ETH Price: $2,178.53 (+0.64%)

Transaction Decoder

Block:
19788848 at May-03-2024 09:59:23 AM +UTC
Transaction Fee:
0.00070631490113088 ETH $1.54
Gas Used:
98,430 Gas / 7.175809216 Gwei

Emitted Events:

332 Vault.Swap( poolId=8BD4A1E74A27182D23B98C10FD21D4FBB0ED4BA00002000000000000000004ED, tokenIn=TempleERC20Token, tokenOut=Dai, amountIn=1000000000000000000000, amountOut=1189258139407452543940 )
333 TempleERC20Token.Transfer( from=[Sender] 0x8995bdaec00ef18fe33425c9d367f87615f9a4df, to=[Receiver] Vault, value=1000000000000000000000 )
334 TempleERC20Token.Approval( owner=[Sender] 0x8995bdaec00ef18fe33425c9d367f87615f9a4df, spender=[Receiver] Vault, value=99987000000000000000000000 )
335 Dai.Transfer( src=[Receiver] Vault, dst=[Sender] 0x8995bdaec00ef18fe33425c9d367f87615f9a4df, wad=1189258139407452543940 )

Account State Difference:

  Address   Before After State Difference Code
0x470EBf5f...2e77CF1b7
(Titan Builder)
5.837637797485324278 Eth5.837665308136735248 Eth0.00002751065141097
0x6B175474...495271d0F
0x8995bdae...615f9a4Df
0.229807028658800448 Eth
Nonce: 240
0.229100713757669568 Eth
Nonce: 241
0.00070631490113088
0xBA122222...d566BF2C8
(Balancer: Vault)

Execution Trace

Vault.swap( singleSwap=[{name:poolId, type:bytes32, order:1, indexed:false, value:8BD4A1E74A27182D23B98C10FD21D4FBB0ED4BA00002000000000000000004ED, valueString:8BD4A1E74A27182D23B98C10FD21D4FBB0ED4BA00002000000000000000004ED}, {name:kind, type:uint8, order:2, indexed:false, value:0, valueString:0}, {name:assetIn, type:address, order:3, indexed:false, value:0x470EBf5f030Ed85Fc1ed4C2d36B9DD02e77CF1b7, valueString:0x470EBf5f030Ed85Fc1ed4C2d36B9DD02e77CF1b7}, {name:assetOut, type:address, order:4, indexed:false, value:0x6B175474E89094C44Da98b954EedeAC495271d0F, valueString:0x6B175474E89094C44Da98b954EedeAC495271d0F}, {name:amount, type:uint256, order:5, indexed:false, value:1000000000000000000000, valueString:1000000000000000000000}, {name:userData, type:bytes, order:6, indexed:false, value:0x, valueString:0x}], funds=[{name:sender, type:address, order:1, indexed:false, value:0x8995bdaeC00EF18fe33425C9D367f87615f9a4Df, valueString:0x8995bdaeC00EF18fe33425C9D367f87615f9a4Df}, {name:fromInternalBalance, type:bool, order:2, indexed:false, value:false, valueString:False}, {name:recipient, type:address, order:3, indexed:false, value:0x8995bdaeC00EF18fe33425C9D367f87615f9a4Df, valueString:0x8995bdaeC00EF18fe33425C9D367f87615f9a4Df}, {name:toInternalBalance, type:bool, order:4, indexed:false, value:false, valueString:False}], limit=1185698033050504323046, deadline=1714731532 ) => ( amountCalculated=1189258139407452543940 )
  • WeightedPool.onSwap( request=[{name:kind, type:uint8, order:1, indexed:false, value:0, valueString:0}, {name:tokenIn, type:address, order:2, indexed:false, value:0x470EBf5f030Ed85Fc1ed4C2d36B9DD02e77CF1b7, valueString:0x470EBf5f030Ed85Fc1ed4C2d36B9DD02e77CF1b7}, {name:tokenOut, type:address, order:3, indexed:false, value:0x6B175474E89094C44Da98b954EedeAC495271d0F, valueString:0x6B175474E89094C44Da98b954EedeAC495271d0F}, {name:amount, type:uint256, order:4, indexed:false, value:1000000000000000000000, valueString:1000000000000000000000}, {name:poolId, type:bytes32, order:5, indexed:false, value:8BD4A1E74A27182D23B98C10FD21D4FBB0ED4BA00002000000000000000004ED, valueString:8BD4A1E74A27182D23B98C10FD21D4FBB0ED4BA00002000000000000000004ED}, {name:lastChangeBlock, type:uint256, order:6, indexed:false, value:19788835, valueString:19788835}, {name:from, type:address, order:7, indexed:false, value:0x8995bdaeC00EF18fe33425C9D367f87615f9a4Df, valueString:0x8995bdaeC00EF18fe33425C9D367f87615f9a4Df}, {name:to, type:address, order:8, indexed:false, value:0x8995bdaeC00EF18fe33425C9D367f87615f9a4Df, valueString:0x8995bdaeC00EF18fe33425C9D367f87615f9a4Df}, {name:userData, type:bytes, order:9, indexed:false, value:0x, valueString:0x}], balanceTokenIn=1000004791746756071577285, balanceTokenOut=1196429296361804325852442 ) => ( 1189258139407452543940 )
  • TempleERC20Token.transferFrom( sender=0x8995bdaeC00EF18fe33425C9D367f87615f9a4Df, recipient=0xBA12222222228d8Ba445958a75a0704d566BF2C8, amount=1000000000000000000000 ) => ( True )
  • Dai.transfer( dst=0x8995bdaeC00EF18fe33425C9D367f87615f9a4Df, wad=1189258139407452543940 ) => ( True )
    swap[Swaps (ln:375)]
    File 1 of 4: Vault
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "./interfaces/IAuthorizer.sol";
    import "./interfaces/IWETH.sol";
    import "./VaultAuthorization.sol";
    import "./FlashLoans.sol";
    import "./Swaps.sol";
    /**
     * @dev The `Vault` is Balancer V2's core contract. A single instance of it exists for the entire network, and it is the
     * entity used to interact with Pools by Liquidity Providers who join and exit them, Traders who swap, and Asset
     * Managers who withdraw and deposit tokens.
     *
     * The `Vault`'s source code is split among a number of sub-contracts, with the goal of improving readability and making
     * understanding the system easier. Most sub-contracts have been marked as `abstract` to explicitly indicate that only
     * the full `Vault` is meant to be deployed.
     *
     * Roughly speaking, these are the contents of each sub-contract:
     *
     *  - `AssetManagers`: Pool token Asset Manager registry, and Asset Manager interactions.
     *  - `Fees`: set and compute protocol fees.
     *  - `FlashLoans`: flash loan transfers and fees.
     *  - `PoolBalances`: Pool joins and exits.
     *  - `PoolRegistry`: Pool registration, ID management, and basic queries.
     *  - `PoolTokens`: Pool token registration and registration, and balance queries.
     *  - `Swaps`: Pool swaps.
     *  - `UserBalance`: manage user balances (Internal Balance operations and external balance transfers)
     *  - `VaultAuthorization`: access control, relayers and signature validation.
     *
     * Additionally, the different Pool specializations are handled by the `GeneralPoolsBalance`,
     * `MinimalSwapInfoPoolsBalance` and `TwoTokenPoolsBalance` sub-contracts, which in turn make use of the
     * `BalanceAllocation` library.
     *
     * The most important goal of the `Vault` is to make token swaps use as little gas as possible. This is reflected in a
     * multitude of design decisions, from minor things like the format used to store Pool IDs, to major features such as
     * the different Pool specialization settings.
     *
     * Finally, the large number of tasks carried out by the Vault means its bytecode is very large, close to exceeding
     * the contract size limit imposed by EIP 170 (https://eips.ethereum.org/EIPS/eip-170). Manual tuning of the source code
     * was required to improve code generation and bring the bytecode size below this limit. This includes extensive
     * utilization of `internal` functions (particularly inside modifiers), usage of named return arguments, dedicated
     * storage access methods, dynamic revert reason generation, and usage of inline assembly, to name a few.
     */
    contract Vault is VaultAuthorization, FlashLoans, Swaps {
        constructor(
            IAuthorizer authorizer,
            IWETH weth,
            uint256 pauseWindowDuration,
            uint256 bufferPeriodDuration
        ) VaultAuthorization(authorizer) AssetHelpers(weth) TemporarilyPausable(pauseWindowDuration, bufferPeriodDuration) {
            // solhint-disable-previous-line no-empty-blocks
        }
        function setPaused(bool paused) external override nonReentrant authenticate {
            _setPaused(paused);
        }
        // solhint-disable-next-line func-name-mixedcase
        function WETH() external view override returns (IWETH) {
            return _WETH();
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    interface IAuthorizer {
        /**
         * @dev Returns true if `account` can perform the action described by `actionId` in the contract `where`.
         */
        function canPerform(
            bytes32 actionId,
            address account,
            address where
        ) external view returns (bool);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "../../lib/openzeppelin/IERC20.sol";
    /**
     * @dev Interface for the WETH token contract used internally for wrapping and unwrapping, to support
     * sending and receiving ETH in joins, swaps, and internal balance deposits and withdrawals.
     */
    interface IWETH is IERC20 {
        function deposit() external payable;
        function withdraw(uint256 amount) external;
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "../lib/helpers/BalancerErrors.sol";
    import "../lib/helpers/Authentication.sol";
    import "../lib/helpers/TemporarilyPausable.sol";
    import "../lib/helpers/BalancerErrors.sol";
    import "../lib/helpers/SignaturesValidator.sol";
    import "../lib/openzeppelin/ReentrancyGuard.sol";
    import "./interfaces/IVault.sol";
    import "./interfaces/IAuthorizer.sol";
    /**
     * @dev Manages access control of Vault permissioned functions by relying on the Authorizer and signature validation.
     *
     * Additionally handles relayer access and approval.
     */
    abstract contract VaultAuthorization is
        IVault,
        ReentrancyGuard,
        Authentication,
        SignaturesValidator,
        TemporarilyPausable
    {
        // Ideally, we'd store the type hashes as immutable state variables to avoid computing the hash at runtime, but
        // unfortunately immutable variables cannot be used in assembly, so we just keep the precomputed hashes instead.
        // _JOIN_TYPE_HASH = keccak256("JoinPool(bytes calldata,address sender,uint256 nonce,uint256 deadline)");
        bytes32 private constant _JOIN_TYPE_HASH = 0x3f7b71252bd19113ff48c19c6e004a9bcfcca320a0d74d58e85877cbd7dcae58;
        // _EXIT_TYPE_HASH = keccak256("ExitPool(bytes calldata,address sender,uint256 nonce,uint256 deadline)");
        bytes32 private constant _EXIT_TYPE_HASH = 0x8bbc57f66ea936902f50a71ce12b92c43f3c5340bb40c27c4e90ab84eeae3353;
        // _SWAP_TYPE_HASH = keccak256("Swap(bytes calldata,address sender,uint256 nonce,uint256 deadline)");
        bytes32 private constant _SWAP_TYPE_HASH = 0xe192dcbc143b1e244ad73b813fd3c097b832ad260a157340b4e5e5beda067abe;
        // _BATCH_SWAP_TYPE_HASH = keccak256("BatchSwap(bytes calldata,address sender,uint256 nonce,uint256 deadline)");
        bytes32 private constant _BATCH_SWAP_TYPE_HASH = 0x9bfc43a4d98313c6766986ffd7c916c7481566d9f224c6819af0a53388aced3a;
        // _SET_RELAYER_TYPE_HASH =
        //     keccak256("SetRelayerApproval(bytes calldata,address sender,uint256 nonce,uint256 deadline)");
        bytes32
            private constant _SET_RELAYER_TYPE_HASH = 0xa3f865aa351e51cfeb40f5178d1564bb629fe9030b83caf6361d1baaf5b90b5a;
        IAuthorizer private _authorizer;
        mapping(address => mapping(address => bool)) private _approvedRelayers;
        /**
         * @dev Reverts unless `user` is the caller, or the caller is approved by the Authorizer to call this function (that
         * is, it is a relayer for that function), and either:
         *  a) `user` approved the caller as a relayer (via `setRelayerApproval`), or
         *  b) a valid signature from them was appended to the calldata.
         *
         * Should only be applied to external functions.
         */
        modifier authenticateFor(address user) {
            _authenticateFor(user);
            _;
        }
        constructor(IAuthorizer authorizer)
            // The Vault is a singleton, so it simply uses its own address to disambiguate action identifiers.
            Authentication(bytes32(uint256(address(this))))
            SignaturesValidator("Balancer V2 Vault")
        {
            _setAuthorizer(authorizer);
        }
        function setAuthorizer(IAuthorizer newAuthorizer) external override nonReentrant authenticate {
            _setAuthorizer(newAuthorizer);
        }
        function _setAuthorizer(IAuthorizer newAuthorizer) private {
            emit AuthorizerChanged(newAuthorizer);
            _authorizer = newAuthorizer;
        }
        function getAuthorizer() external view override returns (IAuthorizer) {
            return _authorizer;
        }
        function setRelayerApproval(
            address sender,
            address relayer,
            bool approved
        ) external override nonReentrant whenNotPaused authenticateFor(sender) {
            _approvedRelayers[sender][relayer] = approved;
            emit RelayerApprovalChanged(relayer, sender, approved);
        }
        function hasApprovedRelayer(address user, address relayer) external view override returns (bool) {
            return _hasApprovedRelayer(user, relayer);
        }
        /**
         * @dev Reverts unless `user` is the caller, or the caller is approved by the Authorizer to call the entry point
         * function (that is, it is a relayer for that function) and either:
         *  a) `user` approved the caller as a relayer (via `setRelayerApproval`), or
         *  b) a valid signature from them was appended to the calldata.
         */
        function _authenticateFor(address user) internal {
            if (msg.sender != user) {
                // In this context, 'permission to call a function' means 'being a relayer for a function'.
                _authenticateCaller();
                // Being a relayer is not sufficient: `user` must have also approved the caller either via
                // `setRelayerApproval`, or by providing a signature appended to the calldata.
                if (!_hasApprovedRelayer(user, msg.sender)) {
                    _validateSignature(user, Errors.USER_DOESNT_ALLOW_RELAYER);
                }
            }
        }
        /**
         * @dev Returns true if `user` approved `relayer` to act as a relayer for them.
         */
        function _hasApprovedRelayer(address user, address relayer) internal view returns (bool) {
            return _approvedRelayers[user][relayer];
        }
        function _canPerform(bytes32 actionId, address user) internal view override returns (bool) {
            // Access control is delegated to the Authorizer.
            return _authorizer.canPerform(actionId, user, address(this));
        }
        function _typeHash() internal pure override returns (bytes32 hash) {
            // This is a simple switch-case statement, trivially written in Solidity by chaining else-if statements, but the
            // assembly implementation results in much denser bytecode.
            // solhint-disable-next-line no-inline-assembly
            assembly {
                // The function selector is located at the first 4 bytes of calldata. We copy the first full calldata
                // 256 word, and then perform a logical shift to the right, moving the selector to the least significant
                // 4 bytes.
                let selector := shr(224, calldataload(0))
                // With the selector in the least significant 4 bytes, we can use 4 byte literals with leading zeros,
                // resulting in dense bytecode (PUSH4 opcodes).
                switch selector
                    case 0xb95cac28 {
                        hash := _JOIN_TYPE_HASH
                    }
                    case 0x8bdb3913 {
                        hash := _EXIT_TYPE_HASH
                    }
                    case 0x52bbbe29 {
                        hash := _SWAP_TYPE_HASH
                    }
                    case 0x945bcec9 {
                        hash := _BATCH_SWAP_TYPE_HASH
                    }
                    case 0xfa6e671d {
                        hash := _SET_RELAYER_TYPE_HASH
                    }
                    default {
                        hash := 0x0000000000000000000000000000000000000000000000000000000000000000
                    }
            }
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    // This flash loan provider was based on the Aave protocol's open source
    // implementation and terminology and interfaces are intentionally kept
    // similar
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "../lib/helpers/BalancerErrors.sol";
    import "../lib/openzeppelin/IERC20.sol";
    import "../lib/openzeppelin/ReentrancyGuard.sol";
    import "../lib/openzeppelin/SafeERC20.sol";
    import "./Fees.sol";
    import "./interfaces/IFlashLoanRecipient.sol";
    /**
     * @dev Handles Flash Loans through the Vault. Calls the `receiveFlashLoan` hook on the flash loan recipient
     * contract, which implements the `IFlashLoanRecipient` interface.
     */
    abstract contract FlashLoans is Fees, ReentrancyGuard, TemporarilyPausable {
        using SafeERC20 for IERC20;
        function flashLoan(
            IFlashLoanRecipient recipient,
            IERC20[] memory tokens,
            uint256[] memory amounts,
            bytes memory userData
        ) external override nonReentrant whenNotPaused {
            InputHelpers.ensureInputLengthMatch(tokens.length, amounts.length);
            uint256[] memory feeAmounts = new uint256[](tokens.length);
            uint256[] memory preLoanBalances = new uint256[](tokens.length);
            // Used to ensure `tokens` is sorted in ascending order, which ensures token uniqueness.
            IERC20 previousToken = IERC20(0);
            for (uint256 i = 0; i < tokens.length; ++i) {
                IERC20 token = tokens[i];
                uint256 amount = amounts[i];
                _require(token > previousToken, token == IERC20(0) ? Errors.ZERO_TOKEN : Errors.UNSORTED_TOKENS);
                previousToken = token;
                preLoanBalances[i] = token.balanceOf(address(this));
                feeAmounts[i] = _calculateFlashLoanFeeAmount(amount);
                _require(preLoanBalances[i] >= amount, Errors.INSUFFICIENT_FLASH_LOAN_BALANCE);
                token.safeTransfer(address(recipient), amount);
            }
            recipient.receiveFlashLoan(tokens, amounts, feeAmounts, userData);
            for (uint256 i = 0; i < tokens.length; ++i) {
                IERC20 token = tokens[i];
                uint256 preLoanBalance = preLoanBalances[i];
                // Checking for loan repayment first (without accounting for fees) makes for simpler debugging, and results
                // in more accurate revert reasons if the flash loan protocol fee percentage is zero.
                uint256 postLoanBalance = token.balanceOf(address(this));
                _require(postLoanBalance >= preLoanBalance, Errors.INVALID_POST_LOAN_BALANCE);
                // No need for checked arithmetic since we know the loan was fully repaid.
                uint256 receivedFeeAmount = postLoanBalance - preLoanBalance;
                _require(receivedFeeAmount >= feeAmounts[i], Errors.INSUFFICIENT_FLASH_LOAN_FEE_AMOUNT);
                _payFeeAmount(token, receivedFeeAmount);
                emit FlashLoan(recipient, token, amounts[i], receivedFeeAmount);
            }
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "../lib/math/Math.sol";
    import "../lib/helpers/BalancerErrors.sol";
    import "../lib/helpers/InputHelpers.sol";
    import "../lib/openzeppelin/EnumerableMap.sol";
    import "../lib/openzeppelin/EnumerableSet.sol";
    import "../lib/openzeppelin/IERC20.sol";
    import "../lib/openzeppelin/ReentrancyGuard.sol";
    import "../lib/openzeppelin/SafeCast.sol";
    import "../lib/openzeppelin/SafeERC20.sol";
    import "./PoolBalances.sol";
    import "./interfaces/IPoolSwapStructs.sol";
    import "./interfaces/IGeneralPool.sol";
    import "./interfaces/IMinimalSwapInfoPool.sol";
    import "./balances/BalanceAllocation.sol";
    /**
     * Implements the Vault's high-level swap functionality.
     *
     * Users can swap tokens with Pools by calling the `swap` and `batchSwap` functions. They need not trust the Pool
     * contracts to do this: all security checks are made by the Vault.
     *
     * The `swap` function executes a single swap, while `batchSwap` can perform multiple swaps in sequence.
     * In each individual swap, tokens of one kind are sent from the sender to the Pool (this is the 'token in'),
     * and tokens of another kind are sent from the Pool to the recipient in exchange (this is the 'token out').
     * More complex swaps, such as one 'token in' to multiple tokens out can be achieved by batching together
     * individual swaps.
     */
    abstract contract Swaps is ReentrancyGuard, PoolBalances {
        using SafeERC20 for IERC20;
        using EnumerableSet for EnumerableSet.AddressSet;
        using EnumerableMap for EnumerableMap.IERC20ToBytes32Map;
        using Math for int256;
        using Math for uint256;
        using SafeCast for uint256;
        using BalanceAllocation for bytes32;
        function swap(
            SingleSwap memory singleSwap,
            FundManagement memory funds,
            uint256 limit,
            uint256 deadline
        )
            external
            payable
            override
            nonReentrant
            whenNotPaused
            authenticateFor(funds.sender)
            returns (uint256 amountCalculated)
        {
            // The deadline is timestamp-based: it should not be relied upon for sub-minute accuracy.
            // solhint-disable-next-line not-rely-on-time
            _require(block.timestamp <= deadline, Errors.SWAP_DEADLINE);
            // This revert reason is for consistency with `batchSwap`: an equivalent `swap` performed using that function
            // would result in this error.
            _require(singleSwap.amount > 0, Errors.UNKNOWN_AMOUNT_IN_FIRST_SWAP);
            IERC20 tokenIn = _translateToIERC20(singleSwap.assetIn);
            IERC20 tokenOut = _translateToIERC20(singleSwap.assetOut);
            _require(tokenIn != tokenOut, Errors.CANNOT_SWAP_SAME_TOKEN);
            // Initializing each struct field one-by-one uses less gas than setting all at once.
            IPoolSwapStructs.SwapRequest memory poolRequest;
            poolRequest.poolId = singleSwap.poolId;
            poolRequest.kind = singleSwap.kind;
            poolRequest.tokenIn = tokenIn;
            poolRequest.tokenOut = tokenOut;
            poolRequest.amount = singleSwap.amount;
            poolRequest.userData = singleSwap.userData;
            poolRequest.from = funds.sender;
            poolRequest.to = funds.recipient;
            // The lastChangeBlock field is left uninitialized.
            uint256 amountIn;
            uint256 amountOut;
            (amountCalculated, amountIn, amountOut) = _swapWithPool(poolRequest);
            _require(singleSwap.kind == SwapKind.GIVEN_IN ? amountOut >= limit : amountIn <= limit, Errors.SWAP_LIMIT);
            _receiveAsset(singleSwap.assetIn, amountIn, funds.sender, funds.fromInternalBalance);
            _sendAsset(singleSwap.assetOut, amountOut, funds.recipient, funds.toInternalBalance);
            // If the asset in is ETH, then `amountIn` ETH was wrapped into WETH.
            _handleRemainingEth(_isETH(singleSwap.assetIn) ? amountIn : 0);
        }
        function batchSwap(
            SwapKind kind,
            BatchSwapStep[] memory swaps,
            IAsset[] memory assets,
            FundManagement memory funds,
            int256[] memory limits,
            uint256 deadline
        )
            external
            payable
            override
            nonReentrant
            whenNotPaused
            authenticateFor(funds.sender)
            returns (int256[] memory assetDeltas)
        {
            // The deadline is timestamp-based: it should not be relied upon for sub-minute accuracy.
            // solhint-disable-next-line not-rely-on-time
            _require(block.timestamp <= deadline, Errors.SWAP_DEADLINE);
            InputHelpers.ensureInputLengthMatch(assets.length, limits.length);
            // Perform the swaps, updating the Pool token balances and computing the net Vault asset deltas.
            assetDeltas = _swapWithPools(swaps, assets, funds, kind);
            // Process asset deltas, by either transferring assets from the sender (for positive deltas) or to the recipient
            // (for negative deltas).
            uint256 wrappedEth = 0;
            for (uint256 i = 0; i < assets.length; ++i) {
                IAsset asset = assets[i];
                int256 delta = assetDeltas[i];
                _require(delta <= limits[i], Errors.SWAP_LIMIT);
                if (delta > 0) {
                    uint256 toReceive = uint256(delta);
                    _receiveAsset(asset, toReceive, funds.sender, funds.fromInternalBalance);
                    if (_isETH(asset)) {
                        wrappedEth = wrappedEth.add(toReceive);
                    }
                } else if (delta < 0) {
                    uint256 toSend = uint256(-delta);
                    _sendAsset(asset, toSend, funds.recipient, funds.toInternalBalance);
                }
            }
            // Handle any used and remaining ETH.
            _handleRemainingEth(wrappedEth);
        }
        // For `_swapWithPools` to handle both 'given in' and 'given out' swaps, it internally tracks the 'given' amount
        // (supplied by the caller), and the 'calculated' amount (returned by the Pool in response to the swap request).
        /**
         * @dev Given the two swap tokens and the swap kind, returns which one is the 'given' token (the token whose
         * amount is supplied by the caller).
         */
        function _tokenGiven(
            SwapKind kind,
            IERC20 tokenIn,
            IERC20 tokenOut
        ) private pure returns (IERC20) {
            return kind == SwapKind.GIVEN_IN ? tokenIn : tokenOut;
        }
        /**
         * @dev Given the two swap tokens and the swap kind, returns which one is the 'calculated' token (the token whose
         * amount is calculated by the Pool).
         */
        function _tokenCalculated(
            SwapKind kind,
            IERC20 tokenIn,
            IERC20 tokenOut
        ) private pure returns (IERC20) {
            return kind == SwapKind.GIVEN_IN ? tokenOut : tokenIn;
        }
        /**
         * @dev Returns an ordered pair (amountIn, amountOut) given the 'given' and 'calculated' amounts, and the swap kind.
         */
        function _getAmounts(
            SwapKind kind,
            uint256 amountGiven,
            uint256 amountCalculated
        ) private pure returns (uint256 amountIn, uint256 amountOut) {
            if (kind == SwapKind.GIVEN_IN) {
                (amountIn, amountOut) = (amountGiven, amountCalculated);
            } else {
                // SwapKind.GIVEN_OUT
                (amountIn, amountOut) = (amountCalculated, amountGiven);
            }
        }
        /**
         * @dev Performs all `swaps`, calling swap hooks on the Pool contracts and updating their balances. Does not cause
         * any transfer of tokens - instead it returns the net Vault token deltas: positive if the Vault should receive
         * tokens, and negative if it should send them.
         */
        function _swapWithPools(
            BatchSwapStep[] memory swaps,
            IAsset[] memory assets,
            FundManagement memory funds,
            SwapKind kind
        ) private returns (int256[] memory assetDeltas) {
            assetDeltas = new int256[](assets.length);
            // These variables could be declared inside the loop, but that causes the compiler to allocate memory on each
            // loop iteration, increasing gas costs.
            BatchSwapStep memory batchSwapStep;
            IPoolSwapStructs.SwapRequest memory poolRequest;
            // These store data about the previous swap here to implement multihop logic across swaps.
            IERC20 previousTokenCalculated;
            uint256 previousAmountCalculated;
            for (uint256 i = 0; i < swaps.length; ++i) {
                batchSwapStep = swaps[i];
                bool withinBounds = batchSwapStep.assetInIndex < assets.length &&
                    batchSwapStep.assetOutIndex < assets.length;
                _require(withinBounds, Errors.OUT_OF_BOUNDS);
                IERC20 tokenIn = _translateToIERC20(assets[batchSwapStep.assetInIndex]);
                IERC20 tokenOut = _translateToIERC20(assets[batchSwapStep.assetOutIndex]);
                _require(tokenIn != tokenOut, Errors.CANNOT_SWAP_SAME_TOKEN);
                // Sentinel value for multihop logic
                if (batchSwapStep.amount == 0) {
                    // When the amount given is zero, we use the calculated amount for the previous swap, as long as the
                    // current swap's given token is the previous calculated token. This makes it possible to swap a
                    // given amount of token A for token B, and then use the resulting token B amount to swap for token C.
                    _require(i > 0, Errors.UNKNOWN_AMOUNT_IN_FIRST_SWAP);
                    bool usingPreviousToken = previousTokenCalculated == _tokenGiven(kind, tokenIn, tokenOut);
                    _require(usingPreviousToken, Errors.MALCONSTRUCTED_MULTIHOP_SWAP);
                    batchSwapStep.amount = previousAmountCalculated;
                }
                // Initializing each struct field one-by-one uses less gas than setting all at once
                poolRequest.poolId = batchSwapStep.poolId;
                poolRequest.kind = kind;
                poolRequest.tokenIn = tokenIn;
                poolRequest.tokenOut = tokenOut;
                poolRequest.amount = batchSwapStep.amount;
                poolRequest.userData = batchSwapStep.userData;
                poolRequest.from = funds.sender;
                poolRequest.to = funds.recipient;
                // The lastChangeBlock field is left uninitialized
                uint256 amountIn;
                uint256 amountOut;
                (previousAmountCalculated, amountIn, amountOut) = _swapWithPool(poolRequest);
                previousTokenCalculated = _tokenCalculated(kind, tokenIn, tokenOut);
                // Accumulate Vault deltas across swaps
                assetDeltas[batchSwapStep.assetInIndex] = assetDeltas[batchSwapStep.assetInIndex].add(amountIn.toInt256());
                assetDeltas[batchSwapStep.assetOutIndex] = assetDeltas[batchSwapStep.assetOutIndex].sub(
                    amountOut.toInt256()
                );
            }
        }
        /**
         * @dev Performs a swap according to the parameters specified in `request`, calling the Pool's contract hook and
         * updating the Pool's balance.
         *
         * Returns the amount of tokens going into or out of the Vault as a result of this swap, depending on the swap kind.
         */
        function _swapWithPool(IPoolSwapStructs.SwapRequest memory request)
            private
            returns (
                uint256 amountCalculated,
                uint256 amountIn,
                uint256 amountOut
            )
        {
            // Get the calculated amount from the Pool and update its balances
            address pool = _getPoolAddress(request.poolId);
            PoolSpecialization specialization = _getPoolSpecialization(request.poolId);
            if (specialization == PoolSpecialization.TWO_TOKEN) {
                amountCalculated = _processTwoTokenPoolSwapRequest(request, IMinimalSwapInfoPool(pool));
            } else if (specialization == PoolSpecialization.MINIMAL_SWAP_INFO) {
                amountCalculated = _processMinimalSwapInfoPoolSwapRequest(request, IMinimalSwapInfoPool(pool));
            } else {
                // PoolSpecialization.GENERAL
                amountCalculated = _processGeneralPoolSwapRequest(request, IGeneralPool(pool));
            }
            (amountIn, amountOut) = _getAmounts(request.kind, request.amount, amountCalculated);
            emit Swap(request.poolId, request.tokenIn, request.tokenOut, amountIn, amountOut);
        }
        function _processTwoTokenPoolSwapRequest(IPoolSwapStructs.SwapRequest memory request, IMinimalSwapInfoPool pool)
            private
            returns (uint256 amountCalculated)
        {
            // For gas efficiency reasons, this function uses low-level knowledge of how Two Token Pool balances are
            // stored internally, instead of using getters and setters for all operations.
            (
                bytes32 tokenABalance,
                bytes32 tokenBBalance,
                TwoTokenPoolBalances storage poolBalances
            ) = _getTwoTokenPoolSharedBalances(request.poolId, request.tokenIn, request.tokenOut);
            // We have the two Pool balances, but we don't know which one is 'token in' or 'token out'.
            bytes32 tokenInBalance;
            bytes32 tokenOutBalance;
            // In Two Token Pools, token A has a smaller address than token B
            if (request.tokenIn < request.tokenOut) {
                // in is A, out is B
                tokenInBalance = tokenABalance;
                tokenOutBalance = tokenBBalance;
            } else {
                // in is B, out is A
                tokenOutBalance = tokenABalance;
                tokenInBalance = tokenBBalance;
            }
            // Perform the swap request and compute the new balances for 'token in' and 'token out' after the swap
            (tokenInBalance, tokenOutBalance, amountCalculated) = _callMinimalSwapInfoPoolOnSwapHook(
                request,
                pool,
                tokenInBalance,
                tokenOutBalance
            );
            // We check the token ordering again to create the new shared cash packed struct
            poolBalances.sharedCash = request.tokenIn < request.tokenOut
                ? BalanceAllocation.toSharedCash(tokenInBalance, tokenOutBalance) // in is A, out is B
                : BalanceAllocation.toSharedCash(tokenOutBalance, tokenInBalance); // in is B, out is A
        }
        function _processMinimalSwapInfoPoolSwapRequest(
            IPoolSwapStructs.SwapRequest memory request,
            IMinimalSwapInfoPool pool
        ) private returns (uint256 amountCalculated) {
            bytes32 tokenInBalance = _getMinimalSwapInfoPoolBalance(request.poolId, request.tokenIn);
            bytes32 tokenOutBalance = _getMinimalSwapInfoPoolBalance(request.poolId, request.tokenOut);
            // Perform the swap request and compute the new balances for 'token in' and 'token out' after the swap
            (tokenInBalance, tokenOutBalance, amountCalculated) = _callMinimalSwapInfoPoolOnSwapHook(
                request,
                pool,
                tokenInBalance,
                tokenOutBalance
            );
            _minimalSwapInfoPoolsBalances[request.poolId][request.tokenIn] = tokenInBalance;
            _minimalSwapInfoPoolsBalances[request.poolId][request.tokenOut] = tokenOutBalance;
        }
        /**
         * @dev Calls the onSwap hook for a Pool that implements IMinimalSwapInfoPool: both Minimal Swap Info and Two Token
         * Pools do this.
         */
        function _callMinimalSwapInfoPoolOnSwapHook(
            IPoolSwapStructs.SwapRequest memory request,
            IMinimalSwapInfoPool pool,
            bytes32 tokenInBalance,
            bytes32 tokenOutBalance
        )
            internal
            returns (
                bytes32 newTokenInBalance,
                bytes32 newTokenOutBalance,
                uint256 amountCalculated
            )
        {
            uint256 tokenInTotal = tokenInBalance.total();
            uint256 tokenOutTotal = tokenOutBalance.total();
            request.lastChangeBlock = Math.max(tokenInBalance.lastChangeBlock(), tokenOutBalance.lastChangeBlock());
            // Perform the swap request callback, and compute the new balances for 'token in' and 'token out' after the swap
            amountCalculated = pool.onSwap(request, tokenInTotal, tokenOutTotal);
            (uint256 amountIn, uint256 amountOut) = _getAmounts(request.kind, request.amount, amountCalculated);
            newTokenInBalance = tokenInBalance.increaseCash(amountIn);
            newTokenOutBalance = tokenOutBalance.decreaseCash(amountOut);
        }
        function _processGeneralPoolSwapRequest(IPoolSwapStructs.SwapRequest memory request, IGeneralPool pool)
            private
            returns (uint256 amountCalculated)
        {
            bytes32 tokenInBalance;
            bytes32 tokenOutBalance;
            // We access both token indexes without checking existence, because we will do it manually immediately after.
            EnumerableMap.IERC20ToBytes32Map storage poolBalances = _generalPoolsBalances[request.poolId];
            uint256 indexIn = poolBalances.unchecked_indexOf(request.tokenIn);
            uint256 indexOut = poolBalances.unchecked_indexOf(request.tokenOut);
            if (indexIn == 0 || indexOut == 0) {
                // The tokens might not be registered because the Pool itself is not registered. We check this to provide a
                // more accurate revert reason.
                _ensureRegisteredPool(request.poolId);
                _revert(Errors.TOKEN_NOT_REGISTERED);
            }
            // EnumerableMap stores indices *plus one* to use the zero index as a sentinel value - because these are valid,
            // we can undo this.
            indexIn -= 1;
            indexOut -= 1;
            uint256 tokenAmount = poolBalances.length();
            uint256[] memory currentBalances = new uint256[](tokenAmount);
            request.lastChangeBlock = 0;
            for (uint256 i = 0; i < tokenAmount; i++) {
                // Because the iteration is bounded by `tokenAmount`, and no tokens are registered or deregistered here, we
                // know `i` is a valid token index and can use `unchecked_valueAt` to save storage reads.
                bytes32 balance = poolBalances.unchecked_valueAt(i);
                currentBalances[i] = balance.total();
                request.lastChangeBlock = Math.max(request.lastChangeBlock, balance.lastChangeBlock());
                if (i == indexIn) {
                    tokenInBalance = balance;
                } else if (i == indexOut) {
                    tokenOutBalance = balance;
                }
            }
            // Perform the swap request callback and compute the new balances for 'token in' and 'token out' after the swap
            amountCalculated = pool.onSwap(request, currentBalances, indexIn, indexOut);
            (uint256 amountIn, uint256 amountOut) = _getAmounts(request.kind, request.amount, amountCalculated);
            tokenInBalance = tokenInBalance.increaseCash(amountIn);
            tokenOutBalance = tokenOutBalance.decreaseCash(amountOut);
            // Because no tokens were registered or deregistered between now or when we retrieved the indexes for
            // 'token in' and 'token out', we can use `unchecked_setAt` to save storage reads.
            poolBalances.unchecked_setAt(indexIn, tokenInBalance);
            poolBalances.unchecked_setAt(indexOut, tokenOutBalance);
        }
        // This function is not marked as `nonReentrant` because the underlying mechanism relies on reentrancy
        function queryBatchSwap(
            SwapKind kind,
            BatchSwapStep[] memory swaps,
            IAsset[] memory assets,
            FundManagement memory funds
        ) external override returns (int256[] memory) {
            // In order to accurately 'simulate' swaps, this function actually does perform the swaps, including calling the
            // Pool hooks and updating balances in storage. However, once it computes the final Vault Deltas, it
            // reverts unconditionally, returning this array as the revert data.
            //
            // By wrapping this reverting call, we can decode the deltas 'returned' and return them as a normal Solidity
            // function would. The only caveat is the function becomes non-view, but off-chain clients can still call it
            // via eth_call to get the expected result.
            //
            // This technique was inspired by the work from the Gnosis team in the Gnosis Safe contract:
            // https://github.com/gnosis/safe-contracts/blob/v1.2.0/contracts/GnosisSafe.sol#L265
            //
            // Most of this function is implemented using inline assembly, as the actual work it needs to do is not
            // significant, and Solidity is not particularly well-suited to generate this behavior, resulting in a large
            // amount of generated bytecode.
            if (msg.sender != address(this)) {
                // We perform an external call to ourselves, forwarding the same calldata. In this call, the else clause of
                // the preceding if statement will be executed instead.
                // solhint-disable-next-line avoid-low-level-calls
                (bool success, ) = address(this).call(msg.data);
                // solhint-disable-next-line no-inline-assembly
                assembly {
                    // This call should always revert to decode the actual asset deltas from the revert reason
                    switch success
                        case 0 {
                            // Note we are manually writing the memory slot 0. We can safely overwrite whatever is
                            // stored there as we take full control of the execution and then immediately return.
                            // We copy the first 4 bytes to check if it matches with the expected signature, otherwise
                            // there was another revert reason and we should forward it.
                            returndatacopy(0, 0, 0x04)
                            let error := and(mload(0), 0xffffffff00000000000000000000000000000000000000000000000000000000)
                            // If the first 4 bytes don't match with the expected signature, we forward the revert reason.
                            if eq(eq(error, 0xfa61cc1200000000000000000000000000000000000000000000000000000000), 0) {
                                returndatacopy(0, 0, returndatasize())
                                revert(0, returndatasize())
                            }
                            // The returndata contains the signature, followed by the raw memory representation of an array:
                            // length + data. We need to return an ABI-encoded representation of this array.
                            // An ABI-encoded array contains an additional field when compared to its raw memory
                            // representation: an offset to the location of the length. The offset itself is 32 bytes long,
                            // so the smallest value we  can use is 32 for the data to be located immediately after it.
                            mstore(0, 32)
                            // We now copy the raw memory array from returndata into memory. Since the offset takes up 32
                            // bytes, we start copying at address 0x20. We also get rid of the error signature, which takes
                            // the first four bytes of returndata.
                            let size := sub(returndatasize(), 0x04)
                            returndatacopy(0x20, 0x04, size)
                            // We finally return the ABI-encoded array, which has a total length equal to that of the array
                            // (returndata), plus the 32 bytes for the offset.
                            return(0, add(size, 32))
                        }
                        default {
                            // This call should always revert, but we fail nonetheless if that didn't happen
                            invalid()
                        }
                }
            } else {
                int256[] memory deltas = _swapWithPools(swaps, assets, funds, kind);
                // solhint-disable-next-line no-inline-assembly
                assembly {
                    // We will return a raw representation of the array in memory, which is composed of a 32 byte length,
                    // followed by the 32 byte int256 values. Because revert expects a size in bytes, we multiply the array
                    // length (stored at `deltas`) by 32.
                    let size := mul(mload(deltas), 32)
                    // We send one extra value for the error signature "QueryError(int256[])" which is 0xfa61cc12.
                    // We store it in the previous slot to the `deltas` array. We know there will be at least one available
                    // slot due to how the memory scratch space works.
                    // We can safely overwrite whatever is stored in this slot as we will revert immediately after that.
                    mstore(sub(deltas, 0x20), 0x00000000000000000000000000000000000000000000000000000000fa61cc12)
                    let start := sub(deltas, 0x04)
                    // When copying from `deltas` into returndata, we copy an additional 36 bytes to also return the array's
                    // length and the error signature.
                    revert(start, add(size, 36))
                }
            }
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.7.0;
    /**
     * @dev Interface of the ERC20 standard as defined in the EIP.
     */
    interface IERC20 {
        /**
         * @dev Returns the amount of tokens in existence.
         */
        function totalSupply() external view returns (uint256);
        /**
         * @dev Returns the amount of tokens owned by `account`.
         */
        function balanceOf(address account) external view returns (uint256);
        /**
         * @dev Moves `amount` tokens from the caller's account to `recipient`.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * Emits a {Transfer} event.
         */
        function transfer(address recipient, uint256 amount) external returns (bool);
        /**
         * @dev Returns the remaining number of tokens that `spender` will be
         * allowed to spend on behalf of `owner` through {transferFrom}. This is
         * zero by default.
         *
         * This value changes when {approve} or {transferFrom} are called.
         */
        function allowance(address owner, address spender) external view returns (uint256);
        /**
         * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * IMPORTANT: Beware that changing an allowance with this method brings the risk
         * that someone may use both the old and the new allowance by unfortunate
         * transaction ordering. One possible solution to mitigate this race
         * condition is to first reduce the spender's allowance to 0 and set the
         * desired value afterwards:
         * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
         *
         * Emits an {Approval} event.
         */
        function approve(address spender, uint256 amount) external returns (bool);
        /**
         * @dev Moves `amount` tokens from `sender` to `recipient` using the
         * allowance mechanism. `amount` is then deducted from the caller's
         * allowance.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * Emits a {Transfer} event.
         */
        function transferFrom(
            address sender,
            address recipient,
            uint256 amount
        ) external returns (bool);
        /**
         * @dev Emitted when `value` tokens are moved from one account (`from`) to
         * another (`to`).
         *
         * Note that `value` may be zero.
         */
        event Transfer(address indexed from, address indexed to, uint256 value);
        /**
         * @dev Emitted when the allowance of a `spender` for an `owner` is set by
         * a call to {approve}. `value` is the new allowance.
         */
        event Approval(address indexed owner, address indexed spender, uint256 value);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    // solhint-disable
    /**
     * @dev Reverts if `condition` is false, with a revert reason containing `errorCode`. Only codes up to 999 are
     * supported.
     */
    function _require(bool condition, uint256 errorCode) pure {
        if (!condition) _revert(errorCode);
    }
    /**
     * @dev Reverts with a revert reason containing `errorCode`. Only codes up to 999 are supported.
     */
    function _revert(uint256 errorCode) pure {
        // We're going to dynamically create a revert string based on the error code, with the following format:
        // 'BAL#{errorCode}'
        // where the code is left-padded with zeroes to three digits (so they range from 000 to 999).
        //
        // We don't have revert strings embedded in the contract to save bytecode size: it takes much less space to store a
        // number (8 to 16 bits) than the individual string characters.
        //
        // The dynamic string creation algorithm that follows could be implemented in Solidity, but assembly allows for a
        // much denser implementation, again saving bytecode size. Given this function unconditionally reverts, this is a
        // safe place to rely on it without worrying about how its usage might affect e.g. memory contents.
        assembly {
            // First, we need to compute the ASCII representation of the error code. We assume that it is in the 0-999
            // range, so we only need to convert three digits. To convert the digits to ASCII, we add 0x30, the value for
            // the '0' character.
            let units := add(mod(errorCode, 10), 0x30)
            errorCode := div(errorCode, 10)
            let tenths := add(mod(errorCode, 10), 0x30)
            errorCode := div(errorCode, 10)
            let hundreds := add(mod(errorCode, 10), 0x30)
            // With the individual characters, we can now construct the full string. The "BAL#" part is a known constant
            // (0x42414c23): we simply shift this by 24 (to provide space for the 3 bytes of the error code), and add the
            // characters to it, each shifted by a multiple of 8.
            // The revert reason is then shifted left by 200 bits (256 minus the length of the string, 7 characters * 8 bits
            // per character = 56) to locate it in the most significant part of the 256 slot (the beginning of a byte
            // array).
            let revertReason := shl(200, add(0x42414c23000000, add(add(units, shl(8, tenths)), shl(16, hundreds))))
            // We can now encode the reason in memory, which can be safely overwritten as we're about to revert. The encoded
            // message will have the following layout:
            // [ revert reason identifier ] [ string location offset ] [ string length ] [ string contents ]
            // The Solidity revert reason identifier is 0x08c739a0, the function selector of the Error(string) function. We
            // also write zeroes to the next 28 bytes of memory, but those are about to be overwritten.
            mstore(0x0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
            // Next is the offset to the location of the string, which will be placed immediately after (20 bytes away).
            mstore(0x04, 0x0000000000000000000000000000000000000000000000000000000000000020)
            // The string length is fixed: 7 characters.
            mstore(0x24, 7)
            // Finally, the string itself is stored.
            mstore(0x44, revertReason)
            // Even if the string is only 7 bytes long, we need to return a full 32 byte slot containing it. The length of
            // the encoded message is therefore 4 + 32 + 32 + 32 = 100.
            revert(0, 100)
        }
    }
    library Errors {
        // Math
        uint256 internal constant ADD_OVERFLOW = 0;
        uint256 internal constant SUB_OVERFLOW = 1;
        uint256 internal constant SUB_UNDERFLOW = 2;
        uint256 internal constant MUL_OVERFLOW = 3;
        uint256 internal constant ZERO_DIVISION = 4;
        uint256 internal constant DIV_INTERNAL = 5;
        uint256 internal constant X_OUT_OF_BOUNDS = 6;
        uint256 internal constant Y_OUT_OF_BOUNDS = 7;
        uint256 internal constant PRODUCT_OUT_OF_BOUNDS = 8;
        uint256 internal constant INVALID_EXPONENT = 9;
        // Input
        uint256 internal constant OUT_OF_BOUNDS = 100;
        uint256 internal constant UNSORTED_ARRAY = 101;
        uint256 internal constant UNSORTED_TOKENS = 102;
        uint256 internal constant INPUT_LENGTH_MISMATCH = 103;
        uint256 internal constant ZERO_TOKEN = 104;
        // Shared pools
        uint256 internal constant MIN_TOKENS = 200;
        uint256 internal constant MAX_TOKENS = 201;
        uint256 internal constant MAX_SWAP_FEE_PERCENTAGE = 202;
        uint256 internal constant MIN_SWAP_FEE_PERCENTAGE = 203;
        uint256 internal constant MINIMUM_BPT = 204;
        uint256 internal constant CALLER_NOT_VAULT = 205;
        uint256 internal constant UNINITIALIZED = 206;
        uint256 internal constant BPT_IN_MAX_AMOUNT = 207;
        uint256 internal constant BPT_OUT_MIN_AMOUNT = 208;
        uint256 internal constant EXPIRED_PERMIT = 209;
        // Pools
        uint256 internal constant MIN_AMP = 300;
        uint256 internal constant MAX_AMP = 301;
        uint256 internal constant MIN_WEIGHT = 302;
        uint256 internal constant MAX_STABLE_TOKENS = 303;
        uint256 internal constant MAX_IN_RATIO = 304;
        uint256 internal constant MAX_OUT_RATIO = 305;
        uint256 internal constant MIN_BPT_IN_FOR_TOKEN_OUT = 306;
        uint256 internal constant MAX_OUT_BPT_FOR_TOKEN_IN = 307;
        uint256 internal constant NORMALIZED_WEIGHT_INVARIANT = 308;
        uint256 internal constant INVALID_TOKEN = 309;
        uint256 internal constant UNHANDLED_JOIN_KIND = 310;
        uint256 internal constant ZERO_INVARIANT = 311;
        // Lib
        uint256 internal constant REENTRANCY = 400;
        uint256 internal constant SENDER_NOT_ALLOWED = 401;
        uint256 internal constant PAUSED = 402;
        uint256 internal constant PAUSE_WINDOW_EXPIRED = 403;
        uint256 internal constant MAX_PAUSE_WINDOW_DURATION = 404;
        uint256 internal constant MAX_BUFFER_PERIOD_DURATION = 405;
        uint256 internal constant INSUFFICIENT_BALANCE = 406;
        uint256 internal constant INSUFFICIENT_ALLOWANCE = 407;
        uint256 internal constant ERC20_TRANSFER_FROM_ZERO_ADDRESS = 408;
        uint256 internal constant ERC20_TRANSFER_TO_ZERO_ADDRESS = 409;
        uint256 internal constant ERC20_MINT_TO_ZERO_ADDRESS = 410;
        uint256 internal constant ERC20_BURN_FROM_ZERO_ADDRESS = 411;
        uint256 internal constant ERC20_APPROVE_FROM_ZERO_ADDRESS = 412;
        uint256 internal constant ERC20_APPROVE_TO_ZERO_ADDRESS = 413;
        uint256 internal constant ERC20_TRANSFER_EXCEEDS_ALLOWANCE = 414;
        uint256 internal constant ERC20_DECREASED_ALLOWANCE_BELOW_ZERO = 415;
        uint256 internal constant ERC20_TRANSFER_EXCEEDS_BALANCE = 416;
        uint256 internal constant ERC20_BURN_EXCEEDS_ALLOWANCE = 417;
        uint256 internal constant SAFE_ERC20_CALL_FAILED = 418;
        uint256 internal constant ADDRESS_INSUFFICIENT_BALANCE = 419;
        uint256 internal constant ADDRESS_CANNOT_SEND_VALUE = 420;
        uint256 internal constant SAFE_CAST_VALUE_CANT_FIT_INT256 = 421;
        uint256 internal constant GRANT_SENDER_NOT_ADMIN = 422;
        uint256 internal constant REVOKE_SENDER_NOT_ADMIN = 423;
        uint256 internal constant RENOUNCE_SENDER_NOT_ALLOWED = 424;
        uint256 internal constant BUFFER_PERIOD_EXPIRED = 425;
        // Vault
        uint256 internal constant INVALID_POOL_ID = 500;
        uint256 internal constant CALLER_NOT_POOL = 501;
        uint256 internal constant SENDER_NOT_ASSET_MANAGER = 502;
        uint256 internal constant USER_DOESNT_ALLOW_RELAYER = 503;
        uint256 internal constant INVALID_SIGNATURE = 504;
        uint256 internal constant EXIT_BELOW_MIN = 505;
        uint256 internal constant JOIN_ABOVE_MAX = 506;
        uint256 internal constant SWAP_LIMIT = 507;
        uint256 internal constant SWAP_DEADLINE = 508;
        uint256 internal constant CANNOT_SWAP_SAME_TOKEN = 509;
        uint256 internal constant UNKNOWN_AMOUNT_IN_FIRST_SWAP = 510;
        uint256 internal constant MALCONSTRUCTED_MULTIHOP_SWAP = 511;
        uint256 internal constant INTERNAL_BALANCE_OVERFLOW = 512;
        uint256 internal constant INSUFFICIENT_INTERNAL_BALANCE = 513;
        uint256 internal constant INVALID_ETH_INTERNAL_BALANCE = 514;
        uint256 internal constant INVALID_POST_LOAN_BALANCE = 515;
        uint256 internal constant INSUFFICIENT_ETH = 516;
        uint256 internal constant UNALLOCATED_ETH = 517;
        uint256 internal constant ETH_TRANSFER = 518;
        uint256 internal constant CANNOT_USE_ETH_SENTINEL = 519;
        uint256 internal constant TOKENS_MISMATCH = 520;
        uint256 internal constant TOKEN_NOT_REGISTERED = 521;
        uint256 internal constant TOKEN_ALREADY_REGISTERED = 522;
        uint256 internal constant TOKENS_ALREADY_SET = 523;
        uint256 internal constant TOKENS_LENGTH_MUST_BE_2 = 524;
        uint256 internal constant NONZERO_TOKEN_BALANCE = 525;
        uint256 internal constant BALANCE_TOTAL_OVERFLOW = 526;
        uint256 internal constant POOL_NO_TOKENS = 527;
        uint256 internal constant INSUFFICIENT_FLASH_LOAN_BALANCE = 528;
        // Fees
        uint256 internal constant SWAP_FEE_PERCENTAGE_TOO_HIGH = 600;
        uint256 internal constant FLASH_LOAN_FEE_PERCENTAGE_TOO_HIGH = 601;
        uint256 internal constant INSUFFICIENT_FLASH_LOAN_FEE_AMOUNT = 602;
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "./BalancerErrors.sol";
    import "./IAuthentication.sol";
    /**
     * @dev Building block for performing access control on external functions.
     *
     * This contract is used via the `authenticate` modifier (or the `_authenticateCaller` function), which can be applied
     * to external functions to only make them callable by authorized accounts.
     *
     * Derived contracts must implement the `_canPerform` function, which holds the actual access control logic.
     */
    abstract contract Authentication is IAuthentication {
        bytes32 private immutable _actionIdDisambiguator;
        /**
         * @dev The main purpose of the `actionIdDisambiguator` is to prevent accidental function selector collisions in
         * multi contract systems.
         *
         * There are two main uses for it:
         *  - if the contract is a singleton, any unique identifier can be used to make the associated action identifiers
         *    unique. The contract's own address is a good option.
         *  - if the contract belongs to a family that shares action identifiers for the same functions, an identifier
         *    shared by the entire family (and no other contract) should be used instead.
         */
        constructor(bytes32 actionIdDisambiguator) {
            _actionIdDisambiguator = actionIdDisambiguator;
        }
        /**
         * @dev Reverts unless the caller is allowed to call this function. Should only be applied to external functions.
         */
        modifier authenticate() {
            _authenticateCaller();
            _;
        }
        /**
         * @dev Reverts unless the caller is allowed to call the entry point function.
         */
        function _authenticateCaller() internal view {
            bytes32 actionId = getActionId(msg.sig);
            _require(_canPerform(actionId, msg.sender), Errors.SENDER_NOT_ALLOWED);
        }
        function getActionId(bytes4 selector) public view override returns (bytes32) {
            // Each external function is dynamically assigned an action identifier as the hash of the disambiguator and the
            // function selector. Disambiguation is necessary to avoid potential collisions in the function selectors of
            // multiple contracts.
            return keccak256(abi.encodePacked(_actionIdDisambiguator, selector));
        }
        function _canPerform(bytes32 actionId, address user) internal view virtual returns (bool);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "./BalancerErrors.sol";
    import "./ITemporarilyPausable.sol";
    /**
     * @dev Allows for a contract to be paused during an initial period after deployment, disabling functionality. Can be
     * used as an emergency switch in case a security vulnerability or threat is identified.
     *
     * The contract can only be paused during the Pause Window, a period that starts at deployment. It can also be
     * unpaused and repaused any number of times during this period. This is intended to serve as a safety measure: it lets
     * system managers react quickly to potentially dangerous situations, knowing that this action is reversible if careful
     * analysis later determines there was a false alarm.
     *
     * If the contract is paused when the Pause Window finishes, it will remain in the paused state through an additional
     * Buffer Period, after which it will be automatically unpaused forever. This is to ensure there is always enough time
     * to react to an emergency, even if the threat is discovered shortly before the Pause Window expires.
     *
     * Note that since the contract can only be paused within the Pause Window, unpausing during the Buffer Period is
     * irreversible.
     */
    abstract contract TemporarilyPausable is ITemporarilyPausable {
        // The Pause Window and Buffer Period are timestamp-based: they should not be relied upon for sub-minute accuracy.
        // solhint-disable not-rely-on-time
        uint256 private constant _MAX_PAUSE_WINDOW_DURATION = 90 days;
        uint256 private constant _MAX_BUFFER_PERIOD_DURATION = 30 days;
        uint256 private immutable _pauseWindowEndTime;
        uint256 private immutable _bufferPeriodEndTime;
        bool private _paused;
        constructor(uint256 pauseWindowDuration, uint256 bufferPeriodDuration) {
            _require(pauseWindowDuration <= _MAX_PAUSE_WINDOW_DURATION, Errors.MAX_PAUSE_WINDOW_DURATION);
            _require(bufferPeriodDuration <= _MAX_BUFFER_PERIOD_DURATION, Errors.MAX_BUFFER_PERIOD_DURATION);
            uint256 pauseWindowEndTime = block.timestamp + pauseWindowDuration;
            _pauseWindowEndTime = pauseWindowEndTime;
            _bufferPeriodEndTime = pauseWindowEndTime + bufferPeriodDuration;
        }
        /**
         * @dev Reverts if the contract is paused.
         */
        modifier whenNotPaused() {
            _ensureNotPaused();
            _;
        }
        /**
         * @dev Returns the current contract pause status, as well as the end times of the Pause Window and Buffer
         * Period.
         */
        function getPausedState()
            external
            view
            override
            returns (
                bool paused,
                uint256 pauseWindowEndTime,
                uint256 bufferPeriodEndTime
            )
        {
            paused = !_isNotPaused();
            pauseWindowEndTime = _getPauseWindowEndTime();
            bufferPeriodEndTime = _getBufferPeriodEndTime();
        }
        /**
         * @dev Sets the pause state to `paused`. The contract can only be paused until the end of the Pause Window, and
         * unpaused until the end of the Buffer Period.
         *
         * Once the Buffer Period expires, this function reverts unconditionally.
         */
        function _setPaused(bool paused) internal {
            if (paused) {
                _require(block.timestamp < _getPauseWindowEndTime(), Errors.PAUSE_WINDOW_EXPIRED);
            } else {
                _require(block.timestamp < _getBufferPeriodEndTime(), Errors.BUFFER_PERIOD_EXPIRED);
            }
            _paused = paused;
            emit PausedStateChanged(paused);
        }
        /**
         * @dev Reverts if the contract is paused.
         */
        function _ensureNotPaused() internal view {
            _require(_isNotPaused(), Errors.PAUSED);
        }
        /**
         * @dev Returns true if the contract is unpaused.
         *
         * Once the Buffer Period expires, the gas cost of calling this function is reduced dramatically, as storage is no
         * longer accessed.
         */
        function _isNotPaused() internal view returns (bool) {
            // After the Buffer Period, the (inexpensive) timestamp check short-circuits the storage access.
            return block.timestamp > _getBufferPeriodEndTime() || !_paused;
        }
        // These getters lead to reduced bytecode size by inlining the immutable variables in a single place.
        function _getPauseWindowEndTime() private view returns (uint256) {
            return _pauseWindowEndTime;
        }
        function _getBufferPeriodEndTime() private view returns (uint256) {
            return _bufferPeriodEndTime;
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "./BalancerErrors.sol";
    import "./ISignaturesValidator.sol";
    import "../openzeppelin/EIP712.sol";
    /**
     * @dev Utility for signing Solidity function calls.
     *
     * This contract relies on the fact that Solidity contracts can be called with extra calldata, and enables
     * meta-transaction schemes by appending an EIP712 signature of the original calldata at the end.
     *
     * Derived contracts must implement the `_typeHash` function to map function selectors to EIP712 structs.
     */
    abstract contract SignaturesValidator is ISignaturesValidator, EIP712 {
        // The appended data consists of a deadline, plus the [v,r,s] signature. For simplicity, we use a full 256 bit slot
        // for each of these values, even if 'v' is typically an 8 bit value.
        uint256 internal constant _EXTRA_CALLDATA_LENGTH = 4 * 32;
        // Replay attack prevention for each user.
        mapping(address => uint256) internal _nextNonce;
        constructor(string memory name) EIP712(name, "1") {
            // solhint-disable-previous-line no-empty-blocks
        }
        function getDomainSeparator() external view override returns (bytes32) {
            return _domainSeparatorV4();
        }
        function getNextNonce(address user) external view override returns (uint256) {
            return _nextNonce[user];
        }
        /**
         * @dev Reverts with `errorCode` unless a valid signature for `user` was appended to the calldata.
         */
        function _validateSignature(address user, uint256 errorCode) internal {
            uint256 nextNonce = _nextNonce[user]++;
            _require(_isSignatureValid(user, nextNonce), errorCode);
        }
        function _isSignatureValid(address user, uint256 nonce) private view returns (bool) {
            uint256 deadline = _deadline();
            // The deadline is timestamp-based: it should not be relied upon for sub-minute accuracy.
            // solhint-disable-next-line not-rely-on-time
            if (deadline < block.timestamp) {
                return false;
            }
            bytes32 typeHash = _typeHash();
            if (typeHash == bytes32(0)) {
                // Prevent accidental signature validation for functions that don't have an associated type hash.
                return false;
            }
            // All type hashes have this format: (bytes calldata, address sender, uint256 nonce, uint256 deadline).
            bytes32 structHash = keccak256(abi.encode(typeHash, keccak256(_calldata()), msg.sender, nonce, deadline));
            bytes32 digest = _hashTypedDataV4(structHash);
            (uint8 v, bytes32 r, bytes32 s) = _signature();
            address recoveredAddress = ecrecover(digest, v, r, s);
            // ecrecover returns the zero address on recover failure, so we need to handle that explicitly.
            return recoveredAddress != address(0) && recoveredAddress == user;
        }
        /**
         * @dev Returns the EIP712 type hash for the current entry point function, which can be identified by its function
         * selector (available as `msg.sig`).
         *
         * The type hash must conform to the following format:
         *  <name>(bytes calldata, address sender, uint256 nonce, uint256 deadline)
         *
         * If 0x00, all signatures will be considered invalid.
         */
        function _typeHash() internal view virtual returns (bytes32);
        /**
         * @dev Extracts the signature deadline from extra calldata.
         *
         * This function returns bogus data if no signature is included.
         */
        function _deadline() internal pure returns (uint256) {
            // The deadline is the first extra argument at the end of the original calldata.
            return uint256(_decodeExtraCalldataWord(0));
        }
        /**
         * @dev Extracts the signature parameters from extra calldata.
         *
         * This function returns bogus data if no signature is included. This is not a security risk, as that data would not
         * be considered a valid signature in the first place.
         */
        function _signature()
            internal
            pure
            returns (
                uint8 v,
                bytes32 r,
                bytes32 s
            )
        {
            // v, r and s are appended after the signature deadline, in that order.
            v = uint8(uint256(_decodeExtraCalldataWord(0x20)));
            r = _decodeExtraCalldataWord(0x40);
            s = _decodeExtraCalldataWord(0x60);
        }
        /**
         * @dev Returns the original calldata, without the extra bytes containing the signature.
         *
         * This function returns bogus data if no signature is included.
         */
        function _calldata() internal pure returns (bytes memory result) {
            result = msg.data; // A calldata to memory assignment results in memory allocation and copy of contents.
            if (result.length > _EXTRA_CALLDATA_LENGTH) {
                // solhint-disable-next-line no-inline-assembly
                assembly {
                    // We simply overwrite the array length with the reduced one.
                    mstore(result, sub(calldatasize(), _EXTRA_CALLDATA_LENGTH))
                }
            }
        }
        /**
         * @dev Returns a 256 bit word from 'extra' calldata, at some offset from the expected end of the original calldata.
         *
         * This function returns bogus data if no signature is included.
         */
        function _decodeExtraCalldataWord(uint256 offset) private pure returns (bytes32 result) {
            // solhint-disable-next-line no-inline-assembly
            assembly {
                result := calldataload(add(sub(calldatasize(), _EXTRA_CALLDATA_LENGTH), offset))
            }
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.7.0;
    import "../helpers/BalancerErrors.sol";
    // Based on the ReentrancyGuard library from OpenZeppelin contracts, altered to reduce bytecode size.
    // Modifier code is inlined by the compiler, which causes its code to appear multiple times in the codebase. By using
    // private functions, we achieve the same end result with slightly higher runtime gas costs but reduced bytecode size.
    /**
     * @dev Contract module that helps prevent reentrant calls to a function.
     *
     * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
     * available, which can be applied to functions to make sure there are no nested
     * (reentrant) calls to them.
     *
     * Note that because there is a single `nonReentrant` guard, functions marked as
     * `nonReentrant` may not call one another. This can be worked around by making
     * those functions `private`, and then adding `external` `nonReentrant` entry
     * points to them.
     *
     * TIP: If you would like to learn more about reentrancy and alternative ways
     * to protect against it, check out our blog post
     * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
     */
    abstract contract ReentrancyGuard {
        // Booleans are more expensive than uint256 or any type that takes up a full
        // word because each write operation emits an extra SLOAD to first read the
        // slot's contents, replace the bits taken up by the boolean, and then write
        // back. This is the compiler's defense against contract upgrades and
        // pointer aliasing, and it cannot be disabled.
        // The values being non-zero value makes deployment a bit more expensive,
        // but in exchange the refund on every call to nonReentrant will be lower in
        // amount. Since refunds are capped to a percentage of the total
        // transaction's gas, it is best to keep them low in cases like this one, to
        // increase the likelihood of the full refund coming into effect.
        uint256 private constant _NOT_ENTERED = 1;
        uint256 private constant _ENTERED = 2;
        uint256 private _status;
        constructor() {
            _status = _NOT_ENTERED;
        }
        /**
         * @dev Prevents a contract from calling itself, directly or indirectly.
         * Calling a `nonReentrant` function from another `nonReentrant`
         * function is not supported. It is possible to prevent this from happening
         * by making the `nonReentrant` function external, and make it call a
         * `private` function that does the actual work.
         */
        modifier nonReentrant() {
            _enterNonReentrant();
            _;
            _exitNonReentrant();
        }
        function _enterNonReentrant() private {
            // On the first call to nonReentrant, _status will be _NOT_ENTERED
            _require(_status != _ENTERED, Errors.REENTRANCY);
            // Any calls to nonReentrant after this point will fail
            _status = _ENTERED;
        }
        function _exitNonReentrant() private {
            // By storing the original value once again, a refund is triggered (see
            // https://eips.ethereum.org/EIPS/eip-2200)
            _status = _NOT_ENTERED;
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma experimental ABIEncoderV2;
    import "../../lib/openzeppelin/IERC20.sol";
    import "./IWETH.sol";
    import "./IAsset.sol";
    import "./IAuthorizer.sol";
    import "./IFlashLoanRecipient.sol";
    import "../ProtocolFeesCollector.sol";
    import "../../lib/helpers/ISignaturesValidator.sol";
    import "../../lib/helpers/ITemporarilyPausable.sol";
    pragma solidity ^0.7.0;
    /**
     * @dev Full external interface for the Vault core contract - no external or public methods exist in the contract that
     * don't override one of these declarations.
     */
    interface IVault is ISignaturesValidator, ITemporarilyPausable {
        // Generalities about the Vault:
        //
        // - Whenever documentation refers to 'tokens', it strictly refers to ERC20-compliant token contracts. Tokens are
        // transferred out of the Vault by calling the `IERC20.transfer` function, and transferred in by calling
        // `IERC20.transferFrom`. In these cases, the sender must have previously allowed the Vault to use their tokens by
        // calling `IERC20.approve`. The only deviation from the ERC20 standard that is supported is functions not returning
        // a boolean value: in these scenarios, a non-reverting call is assumed to be successful.
        //
        // - All non-view functions in the Vault are non-reentrant: calling them while another one is mid-execution (e.g.
        // while execution control is transferred to a token contract during a swap) will result in a revert. View
        // functions can be called in a re-reentrant way, but doing so might cause them to return inconsistent results.
        // Contracts calling view functions in the Vault must make sure the Vault has not already been entered.
        //
        // - View functions revert if referring to either unregistered Pools, or unregistered tokens for registered Pools.
        // Authorizer
        //
        // Some system actions are permissioned, like setting and collecting protocol fees. This permissioning system exists
        // outside of the Vault in the Authorizer contract: the Vault simply calls the Authorizer to check if the caller
        // can perform a given action.
        /**
         * @dev Returns the Vault's Authorizer.
         */
        function getAuthorizer() external view returns (IAuthorizer);
        /**
         * @dev Sets a new Authorizer for the Vault. The caller must be allowed by the current Authorizer to do this.
         *
         * Emits an `AuthorizerChanged` event.
         */
        function setAuthorizer(IAuthorizer newAuthorizer) external;
        /**
         * @dev Emitted when a new authorizer is set by `setAuthorizer`.
         */
        event AuthorizerChanged(IAuthorizer indexed newAuthorizer);
        // Relayers
        //
        // Additionally, it is possible for an account to perform certain actions on behalf of another one, using their
        // Vault ERC20 allowance and Internal Balance. These accounts are said to be 'relayers' for these Vault functions,
        // and are expected to be smart contracts with sound authentication mechanisms. For an account to be able to wield
        // this power, two things must occur:
        //  - The Authorizer must grant the account the permission to be a relayer for the relevant Vault function. This
        //    means that Balancer governance must approve each individual contract to act as a relayer for the intended
        //    functions.
        //  - Each user must approve the relayer to act on their behalf.
        // This double protection means users cannot be tricked into approving malicious relayers (because they will not
        // have been allowed by the Authorizer via governance), nor can malicious relayers approved by a compromised
        // Authorizer or governance drain user funds, since they would also need to be approved by each individual user.
        /**
         * @dev Returns true if `user` has approved `relayer` to act as a relayer for them.
         */
        function hasApprovedRelayer(address user, address relayer) external view returns (bool);
        /**
         * @dev Allows `relayer` to act as a relayer for `sender` if `approved` is true, and disallows it otherwise.
         *
         * Emits a `RelayerApprovalChanged` event.
         */
        function setRelayerApproval(
            address sender,
            address relayer,
            bool approved
        ) external;
        /**
         * @dev Emitted every time a relayer is approved or disapproved by `setRelayerApproval`.
         */
        event RelayerApprovalChanged(address indexed relayer, address indexed sender, bool approved);
        // Internal Balance
        //
        // Users can deposit tokens into the Vault, where they are allocated to their Internal Balance, and later
        // transferred or withdrawn. It can also be used as a source of tokens when joining Pools, as a destination
        // when exiting them, and as either when performing swaps. This usage of Internal Balance results in greatly reduced
        // gas costs when compared to relying on plain ERC20 transfers, leading to large savings for frequent users.
        //
        // Internal Balance management features batching, which means a single contract call can be used to perform multiple
        // operations of different kinds, with different senders and recipients, at once.
        /**
         * @dev Returns `user`'s Internal Balance for a set of tokens.
         */
        function getInternalBalance(address user, IERC20[] memory tokens) external view returns (uint256[] memory);
        /**
         * @dev Performs a set of user balance operations, which involve Internal Balance (deposit, withdraw or transfer)
         * and plain ERC20 transfers using the Vault's allowance. This last feature is particularly useful for relayers, as
         * it lets integrators reuse a user's Vault allowance.
         *
         * For each operation, if the caller is not `sender`, it must be an authorized relayer for them.
         */
        function manageUserBalance(UserBalanceOp[] memory ops) external payable;
        /**
         * @dev Data for `manageUserBalance` operations, which include the possibility for ETH to be sent and received
         without manual WETH wrapping or unwrapping.
         */
        struct UserBalanceOp {
            UserBalanceOpKind kind;
            IAsset asset;
            uint256 amount;
            address sender;
            address payable recipient;
        }
        // There are four possible operations in `manageUserBalance`:
        //
        // - DEPOSIT_INTERNAL
        // Increases the Internal Balance of the `recipient` account by transferring tokens from the corresponding
        // `sender`. The sender must have allowed the Vault to use their tokens via `IERC20.approve()`.
        //
        // ETH can be used by passing the ETH sentinel value as the asset and forwarding ETH in the call: it will be wrapped
        // and deposited as WETH. Any ETH amount remaining will be sent back to the caller (not the sender, which is
        // relevant for relayers).
        //
        // Emits an `InternalBalanceChanged` event.
        //
        //
        // - WITHDRAW_INTERNAL
        // Decreases the Internal Balance of the `sender` account by transferring tokens to the `recipient`.
        //
        // ETH can be used by passing the ETH sentinel value as the asset. This will deduct WETH instead, unwrap it and send
        // it to the recipient as ETH.
        //
        // Emits an `InternalBalanceChanged` event.
        //
        //
        // - TRANSFER_INTERNAL
        // Transfers tokens from the Internal Balance of the `sender` account to the Internal Balance of `recipient`.
        //
        // Reverts if the ETH sentinel value is passed.
        //
        // Emits an `InternalBalanceChanged` event.
        //
        //
        // - TRANSFER_EXTERNAL
        // Transfers tokens from `sender` to `recipient`, using the Vault's ERC20 allowance. This is typically used by
        // relayers, as it lets them reuse a user's Vault allowance.
        //
        // Reverts if the ETH sentinel value is passed.
        //
        // Emits an `ExternalBalanceTransfer` event.
        enum UserBalanceOpKind { DEPOSIT_INTERNAL, WITHDRAW_INTERNAL, TRANSFER_INTERNAL, TRANSFER_EXTERNAL }
        /**
         * @dev Emitted when a user's Internal Balance changes, either from calls to `manageUserBalance`, or through
         * interacting with Pools using Internal Balance.
         *
         * Because Internal Balance works exclusively with ERC20 tokens, ETH deposits and withdrawals will use the WETH
         * address.
         */
        event InternalBalanceChanged(address indexed user, IERC20 indexed token, int256 delta);
        /**
         * @dev Emitted when a user's Vault ERC20 allowance is used by the Vault to transfer tokens to an external account.
         */
        event ExternalBalanceTransfer(IERC20 indexed token, address indexed sender, address recipient, uint256 amount);
        // Pools
        //
        // There are three specialization settings for Pools, which allow for cheaper swaps at the cost of reduced
        // functionality:
        //
        //  - General: no specialization, suited for all Pools. IGeneralPool is used for swap request callbacks, passing the
        // balance of all tokens in the Pool. These Pools have the largest swap costs (because of the extra storage reads),
        // which increase with the number of registered tokens.
        //
        //  - Minimal Swap Info: IMinimalSwapInfoPool is used instead of IGeneralPool, which saves gas by only passing the
        // balance of the two tokens involved in the swap. This is suitable for some pricing algorithms, like the weighted
        // constant product one popularized by Balancer V1. Swap costs are smaller compared to general Pools, and are
        // independent of the number of registered tokens.
        //
        //  - Two Token: only allows two tokens to be registered. This achieves the lowest possible swap gas cost. Like
        // minimal swap info Pools, these are called via IMinimalSwapInfoPool.
        enum PoolSpecialization { GENERAL, MINIMAL_SWAP_INFO, TWO_TOKEN }
        /**
         * @dev Registers the caller account as a Pool with a given specialization setting. Returns the Pool's ID, which
         * is used in all Pool-related functions. Pools cannot be deregistered, nor can the Pool's specialization be
         * changed.
         *
         * The caller is expected to be a smart contract that implements either `IGeneralPool` or `IMinimalSwapInfoPool`,
         * depending on the chosen specialization setting. This contract is known as the Pool's contract.
         *
         * Note that the same contract may register itself as multiple Pools with unique Pool IDs, or in other words,
         * multiple Pools may share the same contract.
         *
         * Emits a `PoolRegistered` event.
         */
        function registerPool(PoolSpecialization specialization) external returns (bytes32);
        /**
         * @dev Emitted when a Pool is registered by calling `registerPool`.
         */
        event PoolRegistered(bytes32 indexed poolId, address indexed poolAddress, PoolSpecialization specialization);
        /**
         * @dev Returns a Pool's contract address and specialization setting.
         */
        function getPool(bytes32 poolId) external view returns (address, PoolSpecialization);
        /**
         * @dev Registers `tokens` for the `poolId` Pool. Must be called by the Pool's contract.
         *
         * Pools can only interact with tokens they have registered. Users join a Pool by transferring registered tokens,
         * exit by receiving registered tokens, and can only swap registered tokens.
         *
         * Each token can only be registered once. For Pools with the Two Token specialization, `tokens` must have a length
         * of two, that is, both tokens must be registered in the same `registerTokens` call, and they must be sorted in
         * ascending order.
         *
         * The `tokens` and `assetManagers` arrays must have the same length, and each entry in these indicates the Asset
         * Manager for the corresponding token. Asset Managers can manage a Pool's tokens via `managePoolBalance`,
         * depositing and withdrawing them directly, and can even set their balance to arbitrary amounts. They are therefore
         * expected to be highly secured smart contracts with sound design principles, and the decision to register an
         * Asset Manager should not be made lightly.
         *
         * Pools can choose not to assign an Asset Manager to a given token by passing in the zero address. Once an Asset
         * Manager is set, it cannot be changed except by deregistering the associated token and registering again with a
         * different Asset Manager.
         *
         * Emits a `TokensRegistered` event.
         */
        function registerTokens(
            bytes32 poolId,
            IERC20[] memory tokens,
            address[] memory assetManagers
        ) external;
        /**
         * @dev Emitted when a Pool registers tokens by calling `registerTokens`.
         */
        event TokensRegistered(bytes32 indexed poolId, IERC20[] tokens, address[] assetManagers);
        /**
         * @dev Deregisters `tokens` for the `poolId` Pool. Must be called by the Pool's contract.
         *
         * Only registered tokens (via `registerTokens`) can be deregistered. Additionally, they must have zero total
         * balance. For Pools with the Two Token specialization, `tokens` must have a length of two, that is, both tokens
         * must be deregistered in the same `deregisterTokens` call.
         *
         * A deregistered token can be re-registered later on, possibly with a different Asset Manager.
         *
         * Emits a `TokensDeregistered` event.
         */
        function deregisterTokens(bytes32 poolId, IERC20[] memory tokens) external;
        /**
         * @dev Emitted when a Pool deregisters tokens by calling `deregisterTokens`.
         */
        event TokensDeregistered(bytes32 indexed poolId, IERC20[] tokens);
        /**
         * @dev Returns detailed information for a Pool's registered token.
         *
         * `cash` is the number of tokens the Vault currently holds for the Pool. `managed` is the number of tokens
         * withdrawn and held outside the Vault by the Pool's token Asset Manager. The Pool's total balance for `token`
         * equals the sum of `cash` and `managed`.
         *
         * Internally, `cash` and `managed` are stored using 112 bits. No action can ever cause a Pool's token `cash`,
         * `managed` or `total` balance to be greater than 2^112 - 1.
         *
         * `lastChangeBlock` is the number of the block in which `token`'s total balance was last modified (via either a
         * join, exit, swap, or Asset Manager update). This value is useful to avoid so-called 'sandwich attacks', for
         * example when developing price oracles. A change of zero (e.g. caused by a swap with amount zero) is considered a
         * change for this purpose, and will update `lastChangeBlock`.
         *
         * `assetManager` is the Pool's token Asset Manager.
         */
        function getPoolTokenInfo(bytes32 poolId, IERC20 token)
            external
            view
            returns (
                uint256 cash,
                uint256 managed,
                uint256 lastChangeBlock,
                address assetManager
            );
        /**
         * @dev Returns a Pool's registered tokens, the total balance for each, and the latest block when *any* of
         * the tokens' `balances` changed.
         *
         * The order of the `tokens` array is the same order that will be used in `joinPool`, `exitPool`, as well as in all
         * Pool hooks (where applicable). Calls to `registerTokens` and `deregisterTokens` may change this order.
         *
         * If a Pool only registers tokens once, and these are sorted in ascending order, they will be stored in the same
         * order as passed to `registerTokens`.
         *
         * Total balances include both tokens held by the Vault and those withdrawn by the Pool's Asset Managers. These are
         * the amounts used by joins, exits and swaps. For a detailed breakdown of token balances, use `getPoolTokenInfo`
         * instead.
         */
        function getPoolTokens(bytes32 poolId)
            external
            view
            returns (
                IERC20[] memory tokens,
                uint256[] memory balances,
                uint256 lastChangeBlock
            );
        /**
         * @dev Called by users to join a Pool, which transfers tokens from `sender` into the Pool's balance. This will
         * trigger custom Pool behavior, which will typically grant something in return to `recipient` - often tokenized
         * Pool shares.
         *
         * If the caller is not `sender`, it must be an authorized relayer for them.
         *
         * The `assets` and `maxAmountsIn` arrays must have the same length, and each entry indicates the maximum amount
         * to send for each asset. The amounts to send are decided by the Pool and not the Vault: it just enforces
         * these maximums.
         *
         * If joining a Pool that holds WETH, it is possible to send ETH directly: the Vault will do the wrapping. To enable
         * this mechanism, the IAsset sentinel value (the zero address) must be passed in the `assets` array instead of the
         * WETH address. Note that it is not possible to combine ETH and WETH in the same join. Any excess ETH will be sent
         * back to the caller (not the sender, which is important for relayers).
         *
         * `assets` must have the same length and order as the array returned by `getPoolTokens`. This prevents issues when
         * interacting with Pools that register and deregister tokens frequently. If sending ETH however, the array must be
         * sorted *before* replacing the WETH address with the ETH sentinel value (the zero address), which means the final
         * `assets` array might not be sorted. Pools with no registered tokens cannot be joined.
         *
         * If `fromInternalBalance` is true, the caller's Internal Balance will be preferred: ERC20 transfers will only
         * be made for the difference between the requested amount and Internal Balance (if any). Note that ETH cannot be
         * withdrawn from Internal Balance: attempting to do so will trigger a revert.
         *
         * This causes the Vault to call the `IBasePool.onJoinPool` hook on the Pool's contract, where Pools implement
         * their own custom logic. This typically requires additional information from the user (such as the expected number
         * of Pool shares). This can be encoded in the `userData` argument, which is ignored by the Vault and passed
         * directly to the Pool's contract, as is `recipient`.
         *
         * Emits a `PoolBalanceChanged` event.
         */
        function joinPool(
            bytes32 poolId,
            address sender,
            address recipient,
            JoinPoolRequest memory request
        ) external payable;
        struct JoinPoolRequest {
            IAsset[] assets;
            uint256[] maxAmountsIn;
            bytes userData;
            bool fromInternalBalance;
        }
        /**
         * @dev Called by users to exit a Pool, which transfers tokens from the Pool's balance to `recipient`. This will
         * trigger custom Pool behavior, which will typically ask for something in return from `sender` - often tokenized
         * Pool shares. The amount of tokens that can be withdrawn is limited by the Pool's `cash` balance (see
         * `getPoolTokenInfo`).
         *
         * If the caller is not `sender`, it must be an authorized relayer for them.
         *
         * The `tokens` and `minAmountsOut` arrays must have the same length, and each entry in these indicates the minimum
         * token amount to receive for each token contract. The amounts to send are decided by the Pool and not the Vault:
         * it just enforces these minimums.
         *
         * If exiting a Pool that holds WETH, it is possible to receive ETH directly: the Vault will do the unwrapping. To
         * enable this mechanism, the IAsset sentinel value (the zero address) must be passed in the `assets` array instead
         * of the WETH address. Note that it is not possible to combine ETH and WETH in the same exit.
         *
         * `assets` must have the same length and order as the array returned by `getPoolTokens`. This prevents issues when
         * interacting with Pools that register and deregister tokens frequently. If receiving ETH however, the array must
         * be sorted *before* replacing the WETH address with the ETH sentinel value (the zero address), which means the
         * final `assets` array might not be sorted. Pools with no registered tokens cannot be exited.
         *
         * If `toInternalBalance` is true, the tokens will be deposited to `recipient`'s Internal Balance. Otherwise,
         * an ERC20 transfer will be performed. Note that ETH cannot be deposited to Internal Balance: attempting to
         * do so will trigger a revert.
         *
         * `minAmountsOut` is the minimum amount of tokens the user expects to get out of the Pool, for each token in the
         * `tokens` array. This array must match the Pool's registered tokens.
         *
         * This causes the Vault to call the `IBasePool.onExitPool` hook on the Pool's contract, where Pools implement
         * their own custom logic. This typically requires additional information from the user (such as the expected number
         * of Pool shares to return). This can be encoded in the `userData` argument, which is ignored by the Vault and
         * passed directly to the Pool's contract.
         *
         * Emits a `PoolBalanceChanged` event.
         */
        function exitPool(
            bytes32 poolId,
            address sender,
            address payable recipient,
            ExitPoolRequest memory request
        ) external;
        struct ExitPoolRequest {
            IAsset[] assets;
            uint256[] minAmountsOut;
            bytes userData;
            bool toInternalBalance;
        }
        /**
         * @dev Emitted when a user joins or exits a Pool by calling `joinPool` or `exitPool`, respectively.
         */
        event PoolBalanceChanged(
            bytes32 indexed poolId,
            address indexed liquidityProvider,
            IERC20[] tokens,
            int256[] deltas,
            uint256[] protocolFeeAmounts
        );
        enum PoolBalanceChangeKind { JOIN, EXIT }
        // Swaps
        //
        // Users can swap tokens with Pools by calling the `swap` and `batchSwap` functions. To do this,
        // they need not trust Pool contracts in any way: all security checks are made by the Vault. They must however be
        // aware of the Pools' pricing algorithms in order to estimate the prices Pools will quote.
        //
        // The `swap` function executes a single swap, while `batchSwap` can perform multiple swaps in sequence.
        // In each individual swap, tokens of one kind are sent from the sender to the Pool (this is the 'token in'),
        // and tokens of another kind are sent from the Pool to the recipient in exchange (this is the 'token out').
        // More complex swaps, such as one token in to multiple tokens out can be achieved by batching together
        // individual swaps.
        //
        // There are two swap kinds:
        //  - 'given in' swaps, where the amount of tokens in (sent to the Pool) is known, and the Pool determines (via the
        // `onSwap` hook) the amount of tokens out (to send to the recipient).
        //  - 'given out' swaps, where the amount of tokens out (received from the Pool) is known, and the Pool determines
        // (via the `onSwap` hook) the amount of tokens in (to receive from the sender).
        //
        // Additionally, it is possible to chain swaps using a placeholder input amount, which the Vault replaces with
        // the calculated output of the previous swap. If the previous swap was 'given in', this will be the calculated
        // tokenOut amount. If the previous swap was 'given out', it will use the calculated tokenIn amount. These extended
        // swaps are known as 'multihop' swaps, since they 'hop' through a number of intermediate tokens before arriving at
        // the final intended token.
        //
        // In all cases, tokens are only transferred in and out of the Vault (or withdrawn from and deposited into Internal
        // Balance) after all individual swaps have been completed, and the net token balance change computed. This makes
        // certain swap patterns, such as multihops, or swaps that interact with the same token pair in multiple Pools, cost
        // much less gas than they would otherwise.
        //
        // It also means that under certain conditions it is possible to perform arbitrage by swapping with multiple
        // Pools in a way that results in net token movement out of the Vault (profit), with no tokens being sent in (only
        // updating the Pool's internal accounting).
        //
        // To protect users from front-running or the market changing rapidly, they supply a list of 'limits' for each token
        // involved in the swap, where either the maximum number of tokens to send (by passing a positive value) or the
        // minimum amount of tokens to receive (by passing a negative value) is specified.
        //
        // Additionally, a 'deadline' timestamp can also be provided, forcing the swap to fail if it occurs after
        // this point in time (e.g. if the transaction failed to be included in a block promptly).
        //
        // If interacting with Pools that hold WETH, it is possible to both send and receive ETH directly: the Vault will do
        // the wrapping and unwrapping. To enable this mechanism, the IAsset sentinel value (the zero address) must be
        // passed in the `assets` array instead of the WETH address. Note that it is possible to combine ETH and WETH in the
        // same swap. Any excess ETH will be sent back to the caller (not the sender, which is relevant for relayers).
        //
        // Finally, Internal Balance can be used when either sending or receiving tokens.
        enum SwapKind { GIVEN_IN, GIVEN_OUT }
        /**
         * @dev Performs a swap with a single Pool.
         *
         * If the swap is 'given in' (the number of tokens to send to the Pool is known), it returns the amount of tokens
         * taken from the Pool, which must be greater than or equal to `limit`.
         *
         * If the swap is 'given out' (the number of tokens to take from the Pool is known), it returns the amount of tokens
         * sent to the Pool, which must be less than or equal to `limit`.
         *
         * Internal Balance usage and the recipient are determined by the `funds` struct.
         *
         * Emits a `Swap` event.
         */
        function swap(
            SingleSwap memory singleSwap,
            FundManagement memory funds,
            uint256 limit,
            uint256 deadline
        ) external payable returns (uint256);
        /**
         * @dev Data for a single swap executed by `swap`. `amount` is either `amountIn` or `amountOut` depending on
         * the `kind` value.
         *
         * `assetIn` and `assetOut` are either token addresses, or the IAsset sentinel value for ETH (the zero address).
         * Note that Pools never interact with ETH directly: it will be wrapped to or unwrapped from WETH by the Vault.
         *
         * The `userData` field is ignored by the Vault, but forwarded to the Pool in the `onSwap` hook, and may be
         * used to extend swap behavior.
         */
        struct SingleSwap {
            bytes32 poolId;
            SwapKind kind;
            IAsset assetIn;
            IAsset assetOut;
            uint256 amount;
            bytes userData;
        }
        /**
         * @dev Performs a series of swaps with one or multiple Pools. In each individual swap, the caller determines either
         * the amount of tokens sent to or received from the Pool, depending on the `kind` value.
         *
         * Returns an array with the net Vault asset balance deltas. Positive amounts represent tokens (or ETH) sent to the
         * Vault, and negative amounts represent tokens (or ETH) sent by the Vault. Each delta corresponds to the asset at
         * the same index in the `assets` array.
         *
         * Swaps are executed sequentially, in the order specified by the `swaps` array. Each array element describes a
         * Pool, the token to be sent to this Pool, the token to receive from it, and an amount that is either `amountIn` or
         * `amountOut` depending on the swap kind.
         *
         * Multihop swaps can be executed by passing an `amount` value of zero for a swap. This will cause the amount in/out
         * of the previous swap to be used as the amount in for the current one. In a 'given in' swap, 'tokenIn' must equal
         * the previous swap's `tokenOut`. For a 'given out' swap, `tokenOut` must equal the previous swap's `tokenIn`.
         *
         * The `assets` array contains the addresses of all assets involved in the swaps. These are either token addresses,
         * or the IAsset sentinel value for ETH (the zero address). Each entry in the `swaps` array specifies tokens in and
         * out by referencing an index in `assets`. Note that Pools never interact with ETH directly: it will be wrapped to
         * or unwrapped from WETH by the Vault.
         *
         * Internal Balance usage, sender, and recipient are determined by the `funds` struct. The `limits` array specifies
         * the minimum or maximum amount of each token the vault is allowed to transfer.
         *
         * `batchSwap` can be used to make a single swap, like `swap` does, but doing so requires more gas than the
         * equivalent `swap` call.
         *
         * Emits `Swap` events.
         */
        function batchSwap(
            SwapKind kind,
            BatchSwapStep[] memory swaps,
            IAsset[] memory assets,
            FundManagement memory funds,
            int256[] memory limits,
            uint256 deadline
        ) external payable returns (int256[] memory);
        /**
         * @dev Data for each individual swap executed by `batchSwap`. The asset in and out fields are indexes into the
         * `assets` array passed to that function, and ETH assets are converted to WETH.
         *
         * If `amount` is zero, the multihop mechanism is used to determine the actual amount based on the amount in/out
         * from the previous swap, depending on the swap kind.
         *
         * The `userData` field is ignored by the Vault, but forwarded to the Pool in the `onSwap` hook, and may be
         * used to extend swap behavior.
         */
        struct BatchSwapStep {
            bytes32 poolId;
            uint256 assetInIndex;
            uint256 assetOutIndex;
            uint256 amount;
            bytes userData;
        }
        /**
         * @dev Emitted for each individual swap performed by `swap` or `batchSwap`.
         */
        event Swap(
            bytes32 indexed poolId,
            IERC20 indexed tokenIn,
            IERC20 indexed tokenOut,
            uint256 amountIn,
            uint256 amountOut
        );
        /**
         * @dev All tokens in a swap are either sent from the `sender` account to the Vault, or from the Vault to the
         * `recipient` account.
         *
         * If the caller is not `sender`, it must be an authorized relayer for them.
         *
         * If `fromInternalBalance` is true, the `sender`'s Internal Balance will be preferred, performing an ERC20
         * transfer for the difference between the requested amount and the User's Internal Balance (if any). The `sender`
         * must have allowed the Vault to use their tokens via `IERC20.approve()`. This matches the behavior of
         * `joinPool`.
         *
         * If `toInternalBalance` is true, tokens will be deposited to `recipient`'s internal balance instead of
         * transferred. This matches the behavior of `exitPool`.
         *
         * Note that ETH cannot be deposited to or withdrawn from Internal Balance: attempting to do so will trigger a
         * revert.
         */
        struct FundManagement {
            address sender;
            bool fromInternalBalance;
            address payable recipient;
            bool toInternalBalance;
        }
        /**
         * @dev Simulates a call to `batchSwap`, returning an array of Vault asset deltas. Calls to `swap` cannot be
         * simulated directly, but an equivalent `batchSwap` call can and will yield the exact same result.
         *
         * Each element in the array corresponds to the asset at the same index, and indicates the number of tokens (or ETH)
         * the Vault would take from the sender (if positive) or send to the recipient (if negative). The arguments it
         * receives are the same that an equivalent `batchSwap` call would receive.
         *
         * Unlike `batchSwap`, this function performs no checks on the sender or recipient field in the `funds` struct.
         * This makes it suitable to be called by off-chain applications via eth_call without needing to hold tokens,
         * approve them for the Vault, or even know a user's address.
         *
         * Note that this function is not 'view' (due to implementation details): the client code must explicitly execute
         * eth_call instead of eth_sendTransaction.
         */
        function queryBatchSwap(
            SwapKind kind,
            BatchSwapStep[] memory swaps,
            IAsset[] memory assets,
            FundManagement memory funds
        ) external returns (int256[] memory assetDeltas);
        // Flash Loans
        /**
         * @dev Performs a 'flash loan', sending tokens to `recipient`, executing the `receiveFlashLoan` hook on it,
         * and then reverting unless the tokens plus a proportional protocol fee have been returned.
         *
         * The `tokens` and `amounts` arrays must have the same length, and each entry in these indicates the loan amount
         * for each token contract. `tokens` must be sorted in ascending order.
         *
         * The 'userData' field is ignored by the Vault, and forwarded as-is to `recipient` as part of the
         * `receiveFlashLoan` call.
         *
         * Emits `FlashLoan` events.
         */
        function flashLoan(
            IFlashLoanRecipient recipient,
            IERC20[] memory tokens,
            uint256[] memory amounts,
            bytes memory userData
        ) external;
        /**
         * @dev Emitted for each individual flash loan performed by `flashLoan`.
         */
        event FlashLoan(IFlashLoanRecipient indexed recipient, IERC20 indexed token, uint256 amount, uint256 feeAmount);
        // Asset Management
        //
        // Each token registered for a Pool can be assigned an Asset Manager, which is able to freely withdraw the Pool's
        // tokens from the Vault, deposit them, or assign arbitrary values to its `managed` balance (see
        // `getPoolTokenInfo`). This makes them extremely powerful and dangerous. Even if an Asset Manager only directly
        // controls one of the tokens in a Pool, a malicious manager could set that token's balance to manipulate the
        // prices of the other tokens, and then drain the Pool with swaps. The risk of using Asset Managers is therefore
        // not constrained to the tokens they are managing, but extends to the entire Pool's holdings.
        //
        // However, a properly designed Asset Manager smart contract can be safely used for the Pool's benefit,
        // for example by lending unused tokens out for interest, or using them to participate in voting protocols.
        //
        // This concept is unrelated to the IAsset interface.
        /**
         * @dev Performs a set of Pool balance operations, which may be either withdrawals, deposits or updates.
         *
         * Pool Balance management features batching, which means a single contract call can be used to perform multiple
         * operations of different kinds, with different Pools and tokens, at once.
         *
         * For each operation, the caller must be registered as the Asset Manager for `token` in `poolId`.
         */
        function managePoolBalance(PoolBalanceOp[] memory ops) external;
        struct PoolBalanceOp {
            PoolBalanceOpKind kind;
            bytes32 poolId;
            IERC20 token;
            uint256 amount;
        }
        /**
         * Withdrawals decrease the Pool's cash, but increase its managed balance, leaving the total balance unchanged.
         *
         * Deposits increase the Pool's cash, but decrease its managed balance, leaving the total balance unchanged.
         *
         * Updates don't affect the Pool's cash balance, but because the managed balance changes, it does alter the total.
         * The external amount can be either increased or decreased by this call (i.e., reporting a gain or a loss).
         */
        enum PoolBalanceOpKind { WITHDRAW, DEPOSIT, UPDATE }
        /**
         * @dev Emitted when a Pool's token Asset Manager alters its balance via `managePoolBalance`.
         */
        event PoolBalanceManaged(
            bytes32 indexed poolId,
            address indexed assetManager,
            IERC20 indexed token,
            int256 cashDelta,
            int256 managedDelta
        );
        // Protocol Fees
        //
        // Some operations cause the Vault to collect tokens in the form of protocol fees, which can then be withdrawn by
        // permissioned accounts.
        //
        // There are two kinds of protocol fees:
        //
        //  - flash loan fees: charged on all flash loans, as a percentage of the amounts lent.
        //
        //  - swap fees: a percentage of the fees charged by Pools when performing swaps. For a number of reasons, including
        // swap gas costs and interface simplicity, protocol swap fees are not charged on each individual swap. Rather,
        // Pools are expected to keep track of how much they have charged in swap fees, and pay any outstanding debts to the
        // Vault when they are joined or exited. This prevents users from joining a Pool with unpaid debt, as well as
        // exiting a Pool in debt without first paying their share.
        /**
         * @dev Returns the current protocol fee module.
         */
        function getProtocolFeesCollector() external view returns (ProtocolFeesCollector);
        /**
         * @dev Safety mechanism to pause most Vault operations in the event of an emergency - typically detection of an
         * error in some part of the system.
         *
         * The Vault can only be paused during an initial time period, after which pausing is forever disabled.
         *
         * While the contract is paused, the following features are disabled:
         * - depositing and transferring internal balance
         * - transferring external balance (using the Vault's allowance)
         * - swaps
         * - joining Pools
         * - Asset Manager interactions
         *
         * Internal Balance can still be withdrawn, and Pools exited.
         */
        function setPaused(bool paused) external;
        /**
         * @dev Returns the Vault's WETH instance.
         */
        function WETH() external view returns (IWETH);
        // solhint-disable-previous-line func-name-mixedcase
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    interface IAuthentication {
        /**
         * @dev Returns the action identifier associated with the external function described by `selector`.
         */
        function getActionId(bytes4 selector) external view returns (bytes32);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    /**
     * @dev Interface for the TemporarilyPausable helper.
     */
    interface ITemporarilyPausable {
        /**
         * @dev Emitted every time the pause state changes by `_setPaused`.
         */
        event PausedStateChanged(bool paused);
        /**
         * @dev Returns the current paused state.
         */
        function getPausedState()
            external
            view
            returns (
                bool paused,
                uint256 pauseWindowEndTime,
                uint256 bufferPeriodEndTime
            );
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    /**
     * @dev Interface for the SignatureValidator helper, used to support meta-transactions.
     */
    interface ISignaturesValidator {
        /**
         * @dev Returns the EIP712 domain separator.
         */
        function getDomainSeparator() external view returns (bytes32);
        /**
         * @dev Returns the next nonce used by an address to sign messages.
         */
        function getNextNonce(address user) external view returns (uint256);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.7.0;
    /**
     * @dev https://eips.ethereum.org/EIPS/eip-712[EIP 712] is a standard for hashing and signing of typed structured data.
     *
     * The encoding specified in the EIP is very generic, and such a generic implementation in Solidity is not feasible,
     * thus this contract does not implement the encoding itself. Protocols need to implement the type-specific encoding
     * they need in their contracts using a combination of `abi.encode` and `keccak256`.
     *
     * This contract implements the EIP 712 domain separator ({_domainSeparatorV4}) that is used as part of the encoding
     * scheme, and the final step of the encoding to obtain the message digest that is then signed via ECDSA
     * ({_hashTypedDataV4}).
     *
     * The implementation of the domain separator was designed to be as efficient as possible while still properly updating
     * the chain id to protect against replay attacks on an eventual fork of the chain.
     *
     * NOTE: This contract implements the version of the encoding known as "v4", as implemented by the JSON RPC method
     * https://docs.metamask.io/guide/signing-data.html[`eth_signTypedDataV4` in MetaMask].
     *
     * _Available since v3.4._
     */
    abstract contract EIP712 {
        /* solhint-disable var-name-mixedcase */
        bytes32 private immutable _HASHED_NAME;
        bytes32 private immutable _HASHED_VERSION;
        bytes32 private immutable _TYPE_HASH;
        /* solhint-enable var-name-mixedcase */
        /**
         * @dev Initializes the domain separator and parameter caches.
         *
         * The meaning of `name` and `version` is specified in
         * https://eips.ethereum.org/EIPS/eip-712#definition-of-domainseparator[EIP 712]:
         *
         * - `name`: the user readable name of the signing domain, i.e. the name of the DApp or the protocol.
         * - `version`: the current major version of the signing domain.
         *
         * NOTE: These parameters cannot be changed except through a xref:learn::upgrading-smart-contracts.adoc[smart
         * contract upgrade].
         */
        constructor(string memory name, string memory version) {
            _HASHED_NAME = keccak256(bytes(name));
            _HASHED_VERSION = keccak256(bytes(version));
            _TYPE_HASH = keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)");
        }
        /**
         * @dev Returns the domain separator for the current chain.
         */
        function _domainSeparatorV4() internal view virtual returns (bytes32) {
            return keccak256(abi.encode(_TYPE_HASH, _HASHED_NAME, _HASHED_VERSION, _getChainId(), address(this)));
        }
        /**
         * @dev Given an already https://eips.ethereum.org/EIPS/eip-712#definition-of-hashstruct[hashed struct], this
         * function returns the hash of the fully encoded EIP712 message for this domain.
         *
         * This hash can be used together with {ECDSA-recover} to obtain the signer of a message. For example:
         *
         * ```solidity
         * bytes32 digest = _hashTypedDataV4(keccak256(abi.encode(
         *     keccak256("Mail(address to,string contents)"),
         *     mailTo,
         *     keccak256(bytes(mailContents))
         * )));
         * address signer = ECDSA.recover(digest, signature);
         * ```
         */
        function _hashTypedDataV4(bytes32 structHash) internal view virtual returns (bytes32) {
            return keccak256(abi.encodePacked("\\x19\\x01", _domainSeparatorV4(), structHash));
        }
        function _getChainId() private view returns (uint256 chainId) {
            // Silence state mutability warning without generating bytecode.
            // See https://github.com/ethereum/solidity/issues/10090#issuecomment-741789128 and
            // https://github.com/ethereum/solidity/issues/2691
            this;
            // solhint-disable-next-line no-inline-assembly
            assembly {
                chainId := chainid()
            }
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    /**
     * @dev This is an empty interface used to represent either ERC20-conforming token contracts or ETH (using the zero
     * address sentinel value). We're just relying on the fact that `interface` can be used to declare new address-like
     * types.
     *
     * This concept is unrelated to a Pool's Asset Managers.
     */
    interface IAsset {
        // solhint-disable-previous-line no-empty-blocks
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    // Inspired by Aave Protocol's IFlashLoanReceiver.
    import "../../lib/openzeppelin/IERC20.sol";
    interface IFlashLoanRecipient {
        /**
         * @dev When `flashLoan` is called on the Vault, it invokes the `receiveFlashLoan` hook on the recipient.
         *
         * At the time of the call, the Vault will have transferred `amounts` for `tokens` to the recipient. Before this
         * call returns, the recipient must have transferred `amounts` plus `feeAmounts` for each token back to the
         * Vault, or else the entire flash loan will revert.
         *
         * `userData` is the same value passed in the `IVault.flashLoan` call.
         */
        function receiveFlashLoan(
            IERC20[] memory tokens,
            uint256[] memory amounts,
            uint256[] memory feeAmounts,
            bytes memory userData
        ) external;
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "../lib/openzeppelin/IERC20.sol";
    import "../lib/helpers/InputHelpers.sol";
    import "../lib/helpers/Authentication.sol";
    import "../lib/openzeppelin/ReentrancyGuard.sol";
    import "../lib/openzeppelin/SafeERC20.sol";
    import "./interfaces/IVault.sol";
    import "./interfaces/IAuthorizer.sol";
    /**
     * @dev This an auxiliary contract to the Vault, deployed by it during construction. It offloads some of the tasks the
     * Vault performs to reduce its overall bytecode size.
     *
     * The current values for all protocol fee percentages are stored here, and any tokens charged as protocol fees are
     * sent to this contract, where they may be withdrawn by authorized entities. All authorization tasks are delegated
     * to the Vault's own authorizer.
     */
    contract ProtocolFeesCollector is Authentication, ReentrancyGuard {
        using SafeERC20 for IERC20;
        // Absolute maximum fee percentages (1e18 = 100%, 1e16 = 1%).
        uint256 private constant _MAX_PROTOCOL_SWAP_FEE_PERCENTAGE = 50e16; // 50%
        uint256 private constant _MAX_PROTOCOL_FLASH_LOAN_FEE_PERCENTAGE = 1e16; // 1%
        IVault public immutable vault;
        // All fee percentages are 18-decimal fixed point numbers.
        // The swap fee is charged whenever a swap occurs, as a percentage of the fee charged by the Pool. These are not
        // actually charged on each individual swap: the `Vault` relies on the Pools being honest and reporting fees due
        // when users join and exit them.
        uint256 private _swapFeePercentage;
        // The flash loan fee is charged whenever a flash loan occurs, as a percentage of the tokens lent.
        uint256 private _flashLoanFeePercentage;
        event SwapFeePercentageChanged(uint256 newSwapFeePercentage);
        event FlashLoanFeePercentageChanged(uint256 newFlashLoanFeePercentage);
        constructor(IVault _vault)
            // The ProtocolFeesCollector is a singleton, so it simply uses its own address to disambiguate action
            // identifiers.
            Authentication(bytes32(uint256(address(this))))
        {
            vault = _vault;
        }
        function withdrawCollectedFees(
            IERC20[] calldata tokens,
            uint256[] calldata amounts,
            address recipient
        ) external nonReentrant authenticate {
            InputHelpers.ensureInputLengthMatch(tokens.length, amounts.length);
            for (uint256 i = 0; i < tokens.length; ++i) {
                IERC20 token = tokens[i];
                uint256 amount = amounts[i];
                token.safeTransfer(recipient, amount);
            }
        }
        function setSwapFeePercentage(uint256 newSwapFeePercentage) external authenticate {
            _require(newSwapFeePercentage <= _MAX_PROTOCOL_SWAP_FEE_PERCENTAGE, Errors.SWAP_FEE_PERCENTAGE_TOO_HIGH);
            _swapFeePercentage = newSwapFeePercentage;
            emit SwapFeePercentageChanged(newSwapFeePercentage);
        }
        function setFlashLoanFeePercentage(uint256 newFlashLoanFeePercentage) external authenticate {
            _require(
                newFlashLoanFeePercentage <= _MAX_PROTOCOL_FLASH_LOAN_FEE_PERCENTAGE,
                Errors.FLASH_LOAN_FEE_PERCENTAGE_TOO_HIGH
            );
            _flashLoanFeePercentage = newFlashLoanFeePercentage;
            emit FlashLoanFeePercentageChanged(newFlashLoanFeePercentage);
        }
        function getSwapFeePercentage() external view returns (uint256) {
            return _swapFeePercentage;
        }
        function getFlashLoanFeePercentage() external view returns (uint256) {
            return _flashLoanFeePercentage;
        }
        function getCollectedFeeAmounts(IERC20[] memory tokens) external view returns (uint256[] memory feeAmounts) {
            feeAmounts = new uint256[](tokens.length);
            for (uint256 i = 0; i < tokens.length; ++i) {
                feeAmounts[i] = tokens[i].balanceOf(address(this));
            }
        }
        function getAuthorizer() external view returns (IAuthorizer) {
            return _getAuthorizer();
        }
        function _canPerform(bytes32 actionId, address account) internal view override returns (bool) {
            return _getAuthorizer().canPerform(actionId, account, address(this));
        }
        function _getAuthorizer() internal view returns (IAuthorizer) {
            return vault.getAuthorizer();
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "../openzeppelin/IERC20.sol";
    import "./BalancerErrors.sol";
    import "../../vault/interfaces/IAsset.sol";
    library InputHelpers {
        function ensureInputLengthMatch(uint256 a, uint256 b) internal pure {
            _require(a == b, Errors.INPUT_LENGTH_MISMATCH);
        }
        function ensureInputLengthMatch(
            uint256 a,
            uint256 b,
            uint256 c
        ) internal pure {
            _require(a == b && b == c, Errors.INPUT_LENGTH_MISMATCH);
        }
        function ensureArrayIsSorted(IAsset[] memory array) internal pure {
            address[] memory addressArray;
            // solhint-disable-next-line no-inline-assembly
            assembly {
                addressArray := array
            }
            ensureArrayIsSorted(addressArray);
        }
        function ensureArrayIsSorted(IERC20[] memory array) internal pure {
            address[] memory addressArray;
            // solhint-disable-next-line no-inline-assembly
            assembly {
                addressArray := array
            }
            ensureArrayIsSorted(addressArray);
        }
        function ensureArrayIsSorted(address[] memory array) internal pure {
            if (array.length < 2) {
                return;
            }
            address previous = array[0];
            for (uint256 i = 1; i < array.length; ++i) {
                address current = array[i];
                _require(previous < current, Errors.UNSORTED_ARRAY);
                previous = current;
            }
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.7.0;
    import "../helpers/BalancerErrors.sol";
    import "./IERC20.sol";
    /**
     * @title SafeERC20
     * @dev Wrappers around ERC20 operations that throw on failure (when the token
     * contract returns false). Tokens that return no value (and instead revert or
     * throw on failure) are also supported, non-reverting calls are assumed to be
     * successful.
     * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
     * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
     */
    library SafeERC20 {
        function safeTransfer(
            IERC20 token,
            address to,
            uint256 value
        ) internal {
            _callOptionalReturn(address(token), abi.encodeWithSelector(token.transfer.selector, to, value));
        }
        function safeTransferFrom(
            IERC20 token,
            address from,
            address to,
            uint256 value
        ) internal {
            _callOptionalReturn(address(token), abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
        }
        /**
         * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
         * on the return value: the return value is optional (but if data is returned, it must not be false).
         *
         * WARNING: `token` is assumed to be a contract: calls to EOAs will *not* revert.
         */
        function _callOptionalReturn(address token, bytes memory data) private {
            // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
            // we're implementing it ourselves.
            (bool success, bytes memory returndata) = token.call(data);
            // If the low-level call didn't succeed we return whatever was returned from it.
            assembly {
                if eq(success, 0) {
                    returndatacopy(0, 0, returndatasize())
                    revert(0, returndatasize())
                }
            }
            // Finally we check the returndata size is either zero or true - note that this check will always pass for EOAs
            _require(returndata.length == 0 || abi.decode(returndata, (bool)), Errors.SAFE_ERC20_CALL_FAILED);
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "../lib/math/FixedPoint.sol";
    import "../lib/helpers/BalancerErrors.sol";
    import "../lib/openzeppelin/IERC20.sol";
    import "../lib/openzeppelin/ReentrancyGuard.sol";
    import "../lib/openzeppelin/SafeERC20.sol";
    import "./ProtocolFeesCollector.sol";
    import "./VaultAuthorization.sol";
    import "./interfaces/IVault.sol";
    /**
     * @dev To reduce the bytecode size of the Vault, most of the protocol fee logic is not here, but in the
     * ProtocolFeesCollector contract.
     */
    abstract contract Fees is IVault {
        using SafeERC20 for IERC20;
        ProtocolFeesCollector private immutable _protocolFeesCollector;
        constructor() {
            _protocolFeesCollector = new ProtocolFeesCollector(IVault(this));
        }
        function getProtocolFeesCollector() public view override returns (ProtocolFeesCollector) {
            return _protocolFeesCollector;
        }
        /**
         * @dev Returns the protocol swap fee percentage.
         */
        function _getProtocolSwapFeePercentage() internal view returns (uint256) {
            return getProtocolFeesCollector().getSwapFeePercentage();
        }
        /**
         * @dev Returns the protocol fee amount to charge for a flash loan of `amount`.
         */
        function _calculateFlashLoanFeeAmount(uint256 amount) internal view returns (uint256) {
            // Fixed point multiplication introduces error: we round up, which means in certain scenarios the charged
            // percentage can be slightly higher than intended.
            uint256 percentage = getProtocolFeesCollector().getFlashLoanFeePercentage();
            return FixedPoint.mulUp(amount, percentage);
        }
        function _payFeeAmount(IERC20 token, uint256 amount) internal {
            if (amount > 0) {
                token.safeTransfer(address(getProtocolFeesCollector()), amount);
            }
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "./LogExpMath.sol";
    import "../helpers/BalancerErrors.sol";
    /* solhint-disable private-vars-leading-underscore */
    library FixedPoint {
        uint256 internal constant ONE = 1e18; // 18 decimal places
        uint256 internal constant MAX_POW_RELATIVE_ERROR = 10000; // 10^(-14)
        // Minimum base for the power function when the exponent is 'free' (larger than ONE).
        uint256 internal constant MIN_POW_BASE_FREE_EXPONENT = 0.7e18;
        function add(uint256 a, uint256 b) internal pure returns (uint256) {
            // Fixed Point addition is the same as regular checked addition
            uint256 c = a + b;
            _require(c >= a, Errors.ADD_OVERFLOW);
            return c;
        }
        function sub(uint256 a, uint256 b) internal pure returns (uint256) {
            // Fixed Point addition is the same as regular checked addition
            _require(b <= a, Errors.SUB_OVERFLOW);
            uint256 c = a - b;
            return c;
        }
        function mulDown(uint256 a, uint256 b) internal pure returns (uint256) {
            uint256 product = a * b;
            _require(a == 0 || product / a == b, Errors.MUL_OVERFLOW);
            return product / ONE;
        }
        function mulUp(uint256 a, uint256 b) internal pure returns (uint256) {
            uint256 product = a * b;
            _require(a == 0 || product / a == b, Errors.MUL_OVERFLOW);
            if (product == 0) {
                return 0;
            } else {
                // The traditional divUp formula is:
                // divUp(x, y) := (x + y - 1) / y
                // To avoid intermediate overflow in the addition, we distribute the division and get:
                // divUp(x, y) := (x - 1) / y + 1
                // Note that this requires x != 0, which we already tested for.
                return ((product - 1) / ONE) + 1;
            }
        }
        function divDown(uint256 a, uint256 b) internal pure returns (uint256) {
            _require(b != 0, Errors.ZERO_DIVISION);
            if (a == 0) {
                return 0;
            } else {
                uint256 aInflated = a * ONE;
                _require(aInflated / a == ONE, Errors.DIV_INTERNAL); // mul overflow
                return aInflated / b;
            }
        }
        function divUp(uint256 a, uint256 b) internal pure returns (uint256) {
            _require(b != 0, Errors.ZERO_DIVISION);
            if (a == 0) {
                return 0;
            } else {
                uint256 aInflated = a * ONE;
                _require(aInflated / a == ONE, Errors.DIV_INTERNAL); // mul overflow
                // The traditional divUp formula is:
                // divUp(x, y) := (x + y - 1) / y
                // To avoid intermediate overflow in the addition, we distribute the division and get:
                // divUp(x, y) := (x - 1) / y + 1
                // Note that this requires x != 0, which we already tested for.
                return ((aInflated - 1) / b) + 1;
            }
        }
        /**
         * @dev Returns x^y, assuming both are fixed point numbers, rounding down. The result is guaranteed to not be above
         * the true value (that is, the error function expected - actual is always positive).
         */
        function powDown(uint256 x, uint256 y) internal pure returns (uint256) {
            uint256 raw = LogExpMath.pow(x, y);
            uint256 maxError = add(mulUp(raw, MAX_POW_RELATIVE_ERROR), 1);
            if (raw < maxError) {
                return 0;
            } else {
                return sub(raw, maxError);
            }
        }
        /**
         * @dev Returns x^y, assuming both are fixed point numbers, rounding up. The result is guaranteed to not be below
         * the true value (that is, the error function expected - actual is always negative).
         */
        function powUp(uint256 x, uint256 y) internal pure returns (uint256) {
            uint256 raw = LogExpMath.pow(x, y);
            uint256 maxError = add(mulUp(raw, MAX_POW_RELATIVE_ERROR), 1);
            return add(raw, maxError);
        }
        /**
         * @dev Returns the complement of a value (1 - x), capped to 0 if x is larger than 1.
         *
         * Useful when computing the complement for values with some level of relative error, as it strips this error and
         * prevents intermediate negative values.
         */
        function complement(uint256 x) internal pure returns (uint256) {
            return (x < ONE) ? (ONE - x) : 0;
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General internal License for more details.
    // You should have received a copy of the GNU General internal License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "../helpers/BalancerErrors.sol";
    /* solhint-disable */
    /**
     * @dev Exponentiation and logarithm functions for 18 decimal fixed point numbers (both base and exponent/argument).
     *
     * Exponentiation and logarithm with arbitrary bases (x^y and log_x(y)) are implemented by conversion to natural
     * exponentiation and logarithm (where the base is Euler's number).
     *
     * @author Fernando Martinelli - @fernandomartinelli
     * @author Sergio Yuhjtman - @sergioyuhjtman
     * @author Daniel Fernandez - @dmf7z
     */
    library LogExpMath {
        // All fixed point multiplications and divisions are inlined. This means we need to divide by ONE when multiplying
        // two numbers, and multiply by ONE when dividing them.
        // All arguments and return values are 18 decimal fixed point numbers.
        int256 constant ONE_18 = 1e18;
        // Internally, intermediate values are computed with higher precision as 20 decimal fixed point numbers, and in the
        // case of ln36, 36 decimals.
        int256 constant ONE_20 = 1e20;
        int256 constant ONE_36 = 1e36;
        // The domain of natural exponentiation is bound by the word size and number of decimals used.
        //
        // Because internally the result will be stored using 20 decimals, the largest possible result is
        // (2^255 - 1) / 10^20, which makes the largest exponent ln((2^255 - 1) / 10^20) = 130.700829182905140221.
        // The smallest possible result is 10^(-18), which makes largest negative argument
        // ln(10^(-18)) = -41.446531673892822312.
        // We use 130.0 and -41.0 to have some safety margin.
        int256 constant MAX_NATURAL_EXPONENT = 130e18;
        int256 constant MIN_NATURAL_EXPONENT = -41e18;
        // Bounds for ln_36's argument. Both ln(0.9) and ln(1.1) can be represented with 36 decimal places in a fixed point
        // 256 bit integer.
        int256 constant LN_36_LOWER_BOUND = ONE_18 - 1e17;
        int256 constant LN_36_UPPER_BOUND = ONE_18 + 1e17;
        uint256 constant MILD_EXPONENT_BOUND = 2**254 / uint256(ONE_20);
        // 18 decimal constants
        int256 constant x0 = 128000000000000000000; // 2ˆ7
        int256 constant a0 = 38877084059945950922200000000000000000000000000000000000; // eˆ(x0) (no decimals)
        int256 constant x1 = 64000000000000000000; // 2ˆ6
        int256 constant a1 = 6235149080811616882910000000; // eˆ(x1) (no decimals)
        // 20 decimal constants
        int256 constant x2 = 3200000000000000000000; // 2ˆ5
        int256 constant a2 = 7896296018268069516100000000000000; // eˆ(x2)
        int256 constant x3 = 1600000000000000000000; // 2ˆ4
        int256 constant a3 = 888611052050787263676000000; // eˆ(x3)
        int256 constant x4 = 800000000000000000000; // 2ˆ3
        int256 constant a4 = 298095798704172827474000; // eˆ(x4)
        int256 constant x5 = 400000000000000000000; // 2ˆ2
        int256 constant a5 = 5459815003314423907810; // eˆ(x5)
        int256 constant x6 = 200000000000000000000; // 2ˆ1
        int256 constant a6 = 738905609893065022723; // eˆ(x6)
        int256 constant x7 = 100000000000000000000; // 2ˆ0
        int256 constant a7 = 271828182845904523536; // eˆ(x7)
        int256 constant x8 = 50000000000000000000; // 2ˆ-1
        int256 constant a8 = 164872127070012814685; // eˆ(x8)
        int256 constant x9 = 25000000000000000000; // 2ˆ-2
        int256 constant a9 = 128402541668774148407; // eˆ(x9)
        int256 constant x10 = 12500000000000000000; // 2ˆ-3
        int256 constant a10 = 113314845306682631683; // eˆ(x10)
        int256 constant x11 = 6250000000000000000; // 2ˆ-4
        int256 constant a11 = 106449445891785942956; // eˆ(x11)
        /**
         * @dev Exponentiation (x^y) with unsigned 18 decimal fixed point base and exponent.
         *
         * Reverts if ln(x) * y is smaller than `MIN_NATURAL_EXPONENT`, or larger than `MAX_NATURAL_EXPONENT`.
         */
        function pow(uint256 x, uint256 y) internal pure returns (uint256) {
            if (y == 0) {
                // We solve the 0^0 indetermination by making it equal one.
                return uint256(ONE_18);
            }
            if (x == 0) {
                return 0;
            }
            // Instead of computing x^y directly, we instead rely on the properties of logarithms and exponentiation to
            // arrive at that result. In particular, exp(ln(x)) = x, and ln(x^y) = y * ln(x). This means
            // x^y = exp(y * ln(x)).
            // The ln function takes a signed value, so we need to make sure x fits in the signed 256 bit range.
            _require(x < 2**255, Errors.X_OUT_OF_BOUNDS);
            int256 x_int256 = int256(x);
            // We will compute y * ln(x) in a single step. Depending on the value of x, we can either use ln or ln_36. In
            // both cases, we leave the division by ONE_18 (due to fixed point multiplication) to the end.
            // This prevents y * ln(x) from overflowing, and at the same time guarantees y fits in the signed 256 bit range.
            _require(y < MILD_EXPONENT_BOUND, Errors.Y_OUT_OF_BOUNDS);
            int256 y_int256 = int256(y);
            int256 logx_times_y;
            if (LN_36_LOWER_BOUND < x_int256 && x_int256 < LN_36_UPPER_BOUND) {
                int256 ln_36_x = ln_36(x_int256);
                // ln_36_x has 36 decimal places, so multiplying by y_int256 isn't as straightforward, since we can't just
                // bring y_int256 to 36 decimal places, as it might overflow. Instead, we perform two 18 decimal
                // multiplications and add the results: one with the first 18 decimals of ln_36_x, and one with the
                // (downscaled) last 18 decimals.
                logx_times_y = ((ln_36_x / ONE_18) * y_int256 + ((ln_36_x % ONE_18) * y_int256) / ONE_18);
            } else {
                logx_times_y = ln(x_int256) * y_int256;
            }
            logx_times_y /= ONE_18;
            // Finally, we compute exp(y * ln(x)) to arrive at x^y
            _require(
                MIN_NATURAL_EXPONENT <= logx_times_y && logx_times_y <= MAX_NATURAL_EXPONENT,
                Errors.PRODUCT_OUT_OF_BOUNDS
            );
            return uint256(exp(logx_times_y));
        }
        /**
         * @dev Natural exponentiation (e^x) with signed 18 decimal fixed point exponent.
         *
         * Reverts if `x` is smaller than MIN_NATURAL_EXPONENT, or larger than `MAX_NATURAL_EXPONENT`.
         */
        function exp(int256 x) internal pure returns (int256) {
            _require(x >= MIN_NATURAL_EXPONENT && x <= MAX_NATURAL_EXPONENT, Errors.INVALID_EXPONENT);
            if (x < 0) {
                // We only handle positive exponents: e^(-x) is computed as 1 / e^x. We can safely make x positive since it
                // fits in the signed 256 bit range (as it is larger than MIN_NATURAL_EXPONENT).
                // Fixed point division requires multiplying by ONE_18.
                return ((ONE_18 * ONE_18) / exp(-x));
            }
            // First, we use the fact that e^(x+y) = e^x * e^y to decompose x into a sum of powers of two, which we call x_n,
            // where x_n == 2^(7 - n), and e^x_n = a_n has been precomputed. We choose the first x_n, x0, to equal 2^7
            // because all larger powers are larger than MAX_NATURAL_EXPONENT, and therefore not present in the
            // decomposition.
            // At the end of this process we will have the product of all e^x_n = a_n that apply, and the remainder of this
            // decomposition, which will be lower than the smallest x_n.
            // exp(x) = k_0 * a_0 * k_1 * a_1 * ... + k_n * a_n * exp(remainder), where each k_n equals either 0 or 1.
            // We mutate x by subtracting x_n, making it the remainder of the decomposition.
            // The first two a_n (e^(2^7) and e^(2^6)) are too large if stored as 18 decimal numbers, and could cause
            // intermediate overflows. Instead we store them as plain integers, with 0 decimals.
            // Additionally, x0 + x1 is larger than MAX_NATURAL_EXPONENT, which means they will not both be present in the
            // decomposition.
            // For each x_n, we test if that term is present in the decomposition (if x is larger than it), and if so deduct
            // it and compute the accumulated product.
            int256 firstAN;
            if (x >= x0) {
                x -= x0;
                firstAN = a0;
            } else if (x >= x1) {
                x -= x1;
                firstAN = a1;
            } else {
                firstAN = 1; // One with no decimal places
            }
            // We now transform x into a 20 decimal fixed point number, to have enhanced precision when computing the
            // smaller terms.
            x *= 100;
            // `product` is the accumulated product of all a_n (except a0 and a1), which starts at 20 decimal fixed point
            // one. Recall that fixed point multiplication requires dividing by ONE_20.
            int256 product = ONE_20;
            if (x >= x2) {
                x -= x2;
                product = (product * a2) / ONE_20;
            }
            if (x >= x3) {
                x -= x3;
                product = (product * a3) / ONE_20;
            }
            if (x >= x4) {
                x -= x4;
                product = (product * a4) / ONE_20;
            }
            if (x >= x5) {
                x -= x5;
                product = (product * a5) / ONE_20;
            }
            if (x >= x6) {
                x -= x6;
                product = (product * a6) / ONE_20;
            }
            if (x >= x7) {
                x -= x7;
                product = (product * a7) / ONE_20;
            }
            if (x >= x8) {
                x -= x8;
                product = (product * a8) / ONE_20;
            }
            if (x >= x9) {
                x -= x9;
                product = (product * a9) / ONE_20;
            }
            // x10 and x11 are unnecessary here since we have high enough precision already.
            // Now we need to compute e^x, where x is small (in particular, it is smaller than x9). We use the Taylor series
            // expansion for e^x: 1 + x + (x^2 / 2!) + (x^3 / 3!) + ... + (x^n / n!).
            int256 seriesSum = ONE_20; // The initial one in the sum, with 20 decimal places.
            int256 term; // Each term in the sum, where the nth term is (x^n / n!).
            // The first term is simply x.
            term = x;
            seriesSum += term;
            // Each term (x^n / n!) equals the previous one times x, divided by n. Since x is a fixed point number,
            // multiplying by it requires dividing by ONE_20, but dividing by the non-fixed point n values does not.
            term = ((term * x) / ONE_20) / 2;
            seriesSum += term;
            term = ((term * x) / ONE_20) / 3;
            seriesSum += term;
            term = ((term * x) / ONE_20) / 4;
            seriesSum += term;
            term = ((term * x) / ONE_20) / 5;
            seriesSum += term;
            term = ((term * x) / ONE_20) / 6;
            seriesSum += term;
            term = ((term * x) / ONE_20) / 7;
            seriesSum += term;
            term = ((term * x) / ONE_20) / 8;
            seriesSum += term;
            term = ((term * x) / ONE_20) / 9;
            seriesSum += term;
            term = ((term * x) / ONE_20) / 10;
            seriesSum += term;
            term = ((term * x) / ONE_20) / 11;
            seriesSum += term;
            term = ((term * x) / ONE_20) / 12;
            seriesSum += term;
            // 12 Taylor terms are sufficient for 18 decimal precision.
            // We now have the first a_n (with no decimals), and the product of all other a_n present, and the Taylor
            // approximation of the exponentiation of the remainder (both with 20 decimals). All that remains is to multiply
            // all three (one 20 decimal fixed point multiplication, dividing by ONE_20, and one integer multiplication),
            // and then drop two digits to return an 18 decimal value.
            return (((product * seriesSum) / ONE_20) * firstAN) / 100;
        }
        /**
         * @dev Natural logarithm (ln(a)) with signed 18 decimal fixed point argument.
         */
        function ln(int256 a) internal pure returns (int256) {
            // The real natural logarithm is not defined for negative numbers or zero.
            _require(a > 0, Errors.OUT_OF_BOUNDS);
            if (a < ONE_18) {
                // Since ln(a^k) = k * ln(a), we can compute ln(a) as ln(a) = ln((1/a)^(-1)) = - ln((1/a)). If a is less
                // than one, 1/a will be greater than one, and this if statement will not be entered in the recursive call.
                // Fixed point division requires multiplying by ONE_18.
                return (-ln((ONE_18 * ONE_18) / a));
            }
            // First, we use the fact that ln^(a * b) = ln(a) + ln(b) to decompose ln(a) into a sum of powers of two, which
            // we call x_n, where x_n == 2^(7 - n), which are the natural logarithm of precomputed quantities a_n (that is,
            // ln(a_n) = x_n). We choose the first x_n, x0, to equal 2^7 because the exponential of all larger powers cannot
            // be represented as 18 fixed point decimal numbers in 256 bits, and are therefore larger than a.
            // At the end of this process we will have the sum of all x_n = ln(a_n) that apply, and the remainder of this
            // decomposition, which will be lower than the smallest a_n.
            // ln(a) = k_0 * x_0 + k_1 * x_1 + ... + k_n * x_n + ln(remainder), where each k_n equals either 0 or 1.
            // We mutate a by subtracting a_n, making it the remainder of the decomposition.
            // For reasons related to how `exp` works, the first two a_n (e^(2^7) and e^(2^6)) are not stored as fixed point
            // numbers with 18 decimals, but instead as plain integers with 0 decimals, so we need to multiply them by
            // ONE_18 to convert them to fixed point.
            // For each a_n, we test if that term is present in the decomposition (if a is larger than it), and if so divide
            // by it and compute the accumulated sum.
            int256 sum = 0;
            if (a >= a0 * ONE_18) {
                a /= a0; // Integer, not fixed point division
                sum += x0;
            }
            if (a >= a1 * ONE_18) {
                a /= a1; // Integer, not fixed point division
                sum += x1;
            }
            // All other a_n and x_n are stored as 20 digit fixed point numbers, so we convert the sum and a to this format.
            sum *= 100;
            a *= 100;
            // Because further a_n are  20 digit fixed point numbers, we multiply by ONE_20 when dividing by them.
            if (a >= a2) {
                a = (a * ONE_20) / a2;
                sum += x2;
            }
            if (a >= a3) {
                a = (a * ONE_20) / a3;
                sum += x3;
            }
            if (a >= a4) {
                a = (a * ONE_20) / a4;
                sum += x4;
            }
            if (a >= a5) {
                a = (a * ONE_20) / a5;
                sum += x5;
            }
            if (a >= a6) {
                a = (a * ONE_20) / a6;
                sum += x6;
            }
            if (a >= a7) {
                a = (a * ONE_20) / a7;
                sum += x7;
            }
            if (a >= a8) {
                a = (a * ONE_20) / a8;
                sum += x8;
            }
            if (a >= a9) {
                a = (a * ONE_20) / a9;
                sum += x9;
            }
            if (a >= a10) {
                a = (a * ONE_20) / a10;
                sum += x10;
            }
            if (a >= a11) {
                a = (a * ONE_20) / a11;
                sum += x11;
            }
            // a is now a small number (smaller than a_11, which roughly equals 1.06). This means we can use a Taylor series
            // that converges rapidly for values of `a` close to one - the same one used in ln_36.
            // Let z = (a - 1) / (a + 1).
            // ln(a) = 2 * (z + z^3 / 3 + z^5 / 5 + z^7 / 7 + ... + z^(2 * n + 1) / (2 * n + 1))
            // Recall that 20 digit fixed point division requires multiplying by ONE_20, and multiplication requires
            // division by ONE_20.
            int256 z = ((a - ONE_20) * ONE_20) / (a + ONE_20);
            int256 z_squared = (z * z) / ONE_20;
            // num is the numerator of the series: the z^(2 * n + 1) term
            int256 num = z;
            // seriesSum holds the accumulated sum of each term in the series, starting with the initial z
            int256 seriesSum = num;
            // In each step, the numerator is multiplied by z^2
            num = (num * z_squared) / ONE_20;
            seriesSum += num / 3;
            num = (num * z_squared) / ONE_20;
            seriesSum += num / 5;
            num = (num * z_squared) / ONE_20;
            seriesSum += num / 7;
            num = (num * z_squared) / ONE_20;
            seriesSum += num / 9;
            num = (num * z_squared) / ONE_20;
            seriesSum += num / 11;
            // 6 Taylor terms are sufficient for 36 decimal precision.
            // Finally, we multiply by 2 (non fixed point) to compute ln(remainder)
            seriesSum *= 2;
            // We now have the sum of all x_n present, and the Taylor approximation of the logarithm of the remainder (both
            // with 20 decimals). All that remains is to sum these two, and then drop two digits to return a 18 decimal
            // value.
            return (sum + seriesSum) / 100;
        }
        /**
         * @dev Logarithm (log(arg, base), with signed 18 decimal fixed point base and argument argument.
         */
        function log(int256 arg, int256 base) internal pure returns (int256) {
            // This performs a simple base change: log(arg, base) = ln(arg) / ln(base).
            // Both logBase and logArg are computed as 36 decimal fixed point numbers, either by using ln_36, or by
            // upscaling.
            int256 logBase;
            if (LN_36_LOWER_BOUND < base && base < LN_36_UPPER_BOUND) {
                logBase = ln_36(base);
            } else {
                logBase = ln(base) * ONE_18;
            }
            int256 logArg;
            if (LN_36_LOWER_BOUND < arg && arg < LN_36_UPPER_BOUND) {
                logArg = ln_36(arg);
            } else {
                logArg = ln(arg) * ONE_18;
            }
            // When dividing, we multiply by ONE_18 to arrive at a result with 18 decimal places
            return (logArg * ONE_18) / logBase;
        }
        /**
         * @dev High precision (36 decimal places) natural logarithm (ln(x)) with signed 18 decimal fixed point argument,
         * for x close to one.
         *
         * Should only be used if x is between LN_36_LOWER_BOUND and LN_36_UPPER_BOUND.
         */
        function ln_36(int256 x) private pure returns (int256) {
            // Since ln(1) = 0, a value of x close to one will yield a very small result, which makes using 36 digits
            // worthwhile.
            // First, we transform x to a 36 digit fixed point value.
            x *= ONE_18;
            // We will use the following Taylor expansion, which converges very rapidly. Let z = (x - 1) / (x + 1).
            // ln(x) = 2 * (z + z^3 / 3 + z^5 / 5 + z^7 / 7 + ... + z^(2 * n + 1) / (2 * n + 1))
            // Recall that 36 digit fixed point division requires multiplying by ONE_36, and multiplication requires
            // division by ONE_36.
            int256 z = ((x - ONE_36) * ONE_36) / (x + ONE_36);
            int256 z_squared = (z * z) / ONE_36;
            // num is the numerator of the series: the z^(2 * n + 1) term
            int256 num = z;
            // seriesSum holds the accumulated sum of each term in the series, starting with the initial z
            int256 seriesSum = num;
            // In each step, the numerator is multiplied by z^2
            num = (num * z_squared) / ONE_36;
            seriesSum += num / 3;
            num = (num * z_squared) / ONE_36;
            seriesSum += num / 5;
            num = (num * z_squared) / ONE_36;
            seriesSum += num / 7;
            num = (num * z_squared) / ONE_36;
            seriesSum += num / 9;
            num = (num * z_squared) / ONE_36;
            seriesSum += num / 11;
            num = (num * z_squared) / ONE_36;
            seriesSum += num / 13;
            num = (num * z_squared) / ONE_36;
            seriesSum += num / 15;
            // 8 Taylor terms are sufficient for 36 decimal precision.
            // All that remains is multiplying by 2 (non fixed point).
            return seriesSum * 2;
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.7.0;
    import "../helpers/BalancerErrors.sol";
    /**
     * @dev Wrappers over Solidity's arithmetic operations with added overflow checks.
     * Adapted from OpenZeppelin's SafeMath library
     */
    library Math {
        /**
         * @dev Returns the addition of two unsigned integers of 256 bits, reverting on overflow.
         */
        function add(uint256 a, uint256 b) internal pure returns (uint256) {
            uint256 c = a + b;
            _require(c >= a, Errors.ADD_OVERFLOW);
            return c;
        }
        /**
         * @dev Returns the addition of two signed integers, reverting on overflow.
         */
        function add(int256 a, int256 b) internal pure returns (int256) {
            int256 c = a + b;
            _require((b >= 0 && c >= a) || (b < 0 && c < a), Errors.ADD_OVERFLOW);
            return c;
        }
        /**
         * @dev Returns the subtraction of two unsigned integers of 256 bits, reverting on overflow.
         */
        function sub(uint256 a, uint256 b) internal pure returns (uint256) {
            _require(b <= a, Errors.SUB_OVERFLOW);
            uint256 c = a - b;
            return c;
        }
        /**
         * @dev Returns the subtraction of two signed integers, reverting on overflow.
         */
        function sub(int256 a, int256 b) internal pure returns (int256) {
            int256 c = a - b;
            _require((b >= 0 && c <= a) || (b < 0 && c > a), Errors.SUB_OVERFLOW);
            return c;
        }
        /**
         * @dev Returns the largest of two numbers of 256 bits.
         */
        function max(uint256 a, uint256 b) internal pure returns (uint256) {
            return a >= b ? a : b;
        }
        /**
         * @dev Returns the smallest of two numbers of 256 bits.
         */
        function min(uint256 a, uint256 b) internal pure returns (uint256) {
            return a < b ? a : b;
        }
        function mul(uint256 a, uint256 b) internal pure returns (uint256) {
            uint256 c = a * b;
            _require(a == 0 || c / a == b, Errors.MUL_OVERFLOW);
            return c;
        }
        function divDown(uint256 a, uint256 b) internal pure returns (uint256) {
            _require(b != 0, Errors.ZERO_DIVISION);
            return a / b;
        }
        function divUp(uint256 a, uint256 b) internal pure returns (uint256) {
            _require(b != 0, Errors.ZERO_DIVISION);
            if (a == 0) {
                return 0;
            } else {
                return 1 + (a - 1) / b;
            }
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.7.0;
    // Based on the EnumerableMap library from OpenZeppelin contracts, altered to include the following:
    //  * a map from IERC20 to bytes32
    //  * entries are stored in mappings instead of arrays, reducing implicit storage reads for out-of-bounds checks
    //  * unchecked_at and unchecked_valueAt, which allow for more gas efficient data reads in some scenarios
    //  * unchecked_indexOf and unchecked_setAt, which allow for more gas efficient data writes in some scenarios
    //
    // Additionally, the base private functions that work on bytes32 were removed and replaced with a native implementation
    // for IERC20 keys, to reduce bytecode size and runtime costs.
    // We're using non-standard casing for the unchecked functions to differentiate them, so we need to turn off that rule
    // solhint-disable func-name-mixedcase
    import "./IERC20.sol";
    import "../helpers/BalancerErrors.sol";
    /**
     * @dev Library for managing an enumerable variant of Solidity's
     * https://solidity.readthedocs.io/en/latest/types.html#mapping-types[`mapping`]
     * type.
     *
     * Maps have the following properties:
     *
     * - Entries are added, removed, and checked for existence in constant time
     * (O(1)).
     * - Entries are enumerated in O(n). No guarantees are made on the ordering.
     *
     * ```
     * contract Example {
     *     // Add the library methods
     *     using EnumerableMap for EnumerableMap.UintToAddressMap;
     *
     *     // Declare a set state variable
     *     EnumerableMap.UintToAddressMap private myMap;
     * }
     * ```
     */
    library EnumerableMap {
        // The original OpenZeppelin implementation uses a generic Map type with bytes32 keys: this was replaced with
        // IERC20ToBytes32Map, which uses IERC20 keys natively, resulting in more dense bytecode.
        struct IERC20ToBytes32MapEntry {
            IERC20 _key;
            bytes32 _value;
        }
        struct IERC20ToBytes32Map {
            // Number of entries in the map
            uint256 _length;
            // Storage of map keys and values
            mapping(uint256 => IERC20ToBytes32MapEntry) _entries;
            // Position of the entry defined by a key in the `entries` array, plus 1
            // because index 0 means a key is not in the map.
            mapping(IERC20 => uint256) _indexes;
        }
        /**
         * @dev Adds a key-value pair to a map, or updates the value for an existing
         * key. O(1).
         *
         * Returns true if the key was added to the map, that is if it was not
         * already present.
         */
        function set(
            IERC20ToBytes32Map storage map,
            IERC20 key,
            bytes32 value
        ) internal returns (bool) {
            // We read and store the key's index to prevent multiple reads from the same storage slot
            uint256 keyIndex = map._indexes[key];
            // Equivalent to !contains(map, key)
            if (keyIndex == 0) {
                uint256 previousLength = map._length;
                map._entries[previousLength] = IERC20ToBytes32MapEntry({ _key: key, _value: value });
                map._length = previousLength + 1;
                // The entry is stored at previousLength, but we add 1 to all indexes
                // and use 0 as a sentinel value
                map._indexes[key] = previousLength + 1;
                return true;
            } else {
                map._entries[keyIndex - 1]._value = value;
                return false;
            }
        }
        /**
         * @dev Updates the value for an entry, given its key's index. The key index can be retrieved via
         * {unchecked_indexOf}, and it should be noted that key indices may change when calling {set} or {remove}. O(1).
         *
         * This function performs one less storage read than {set}, but it should only be used when `index` is known to be
         * within bounds.
         */
        function unchecked_setAt(
            IERC20ToBytes32Map storage map,
            uint256 index,
            bytes32 value
        ) internal {
            map._entries[index]._value = value;
        }
        /**
         * @dev Removes a key-value pair from a map. O(1).
         *
         * Returns true if the key was removed from the map, that is if it was present.
         */
        function remove(IERC20ToBytes32Map storage map, IERC20 key) internal returns (bool) {
            // We read and store the key's index to prevent multiple reads from the same storage slot
            uint256 keyIndex = map._indexes[key];
            // Equivalent to contains(map, key)
            if (keyIndex != 0) {
                // To delete a key-value pair from the _entries pseudo-array in O(1), we swap the entry to delete with the
                // one at the highest index, and then remove this last entry (sometimes called as 'swap and pop').
                // This modifies the order of the pseudo-array, as noted in {at}.
                uint256 toDeleteIndex = keyIndex - 1;
                uint256 lastIndex = map._length - 1;
                // When the entry to delete is the last one, the swap operation is unnecessary. However, since this occurs
                // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.
                IERC20ToBytes32MapEntry storage lastEntry = map._entries[lastIndex];
                // Move the last entry to the index where the entry to delete is
                map._entries[toDeleteIndex] = lastEntry;
                // Update the index for the moved entry
                map._indexes[lastEntry._key] = toDeleteIndex + 1; // All indexes are 1-based
                // Delete the slot where the moved entry was stored
                delete map._entries[lastIndex];
                map._length = lastIndex;
                // Delete the index for the deleted slot
                delete map._indexes[key];
                return true;
            } else {
                return false;
            }
        }
        /**
         * @dev Returns true if the key is in the map. O(1).
         */
        function contains(IERC20ToBytes32Map storage map, IERC20 key) internal view returns (bool) {
            return map._indexes[key] != 0;
        }
        /**
         * @dev Returns the number of key-value pairs in the map. O(1).
         */
        function length(IERC20ToBytes32Map storage map) internal view returns (uint256) {
            return map._length;
        }
        /**
         * @dev Returns the key-value pair stored at position `index` in the map. O(1).
         *
         * Note that there are no guarantees on the ordering of entries inside the
         * array, and it may change when more entries are added or removed.
         *
         * Requirements:
         *
         * - `index` must be strictly less than {length}.
         */
        function at(IERC20ToBytes32Map storage map, uint256 index) internal view returns (IERC20, bytes32) {
            _require(map._length > index, Errors.OUT_OF_BOUNDS);
            return unchecked_at(map, index);
        }
        /**
         * @dev Same as {at}, except this doesn't revert if `index` it outside of the map (i.e. if it is equal or larger
         * than {length}). O(1).
         *
         * This function performs one less storage read than {at}, but should only be used when `index` is known to be
         * within bounds.
         */
        function unchecked_at(IERC20ToBytes32Map storage map, uint256 index) internal view returns (IERC20, bytes32) {
            IERC20ToBytes32MapEntry storage entry = map._entries[index];
            return (entry._key, entry._value);
        }
        /**
         * @dev Same as {unchecked_At}, except it only returns the value and not the key (performing one less storage
         * read). O(1).
         */
        function unchecked_valueAt(IERC20ToBytes32Map storage map, uint256 index) internal view returns (bytes32) {
            return map._entries[index]._value;
        }
        /**
         * @dev Returns the value associated with `key`. O(1).
         *
         * Requirements:
         *
         * - `key` must be in the map. Reverts with `errorCode` otherwise.
         */
        function get(
            IERC20ToBytes32Map storage map,
            IERC20 key,
            uint256 errorCode
        ) internal view returns (bytes32) {
            uint256 index = map._indexes[key];
            _require(index > 0, errorCode);
            return unchecked_valueAt(map, index - 1);
        }
        /**
         * @dev Returns the index for `key` **plus one**. Does not revert if the key is not in the map, and returns 0
         * instead.
         */
        function unchecked_indexOf(IERC20ToBytes32Map storage map, IERC20 key) internal view returns (uint256) {
            return map._indexes[key];
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.7.0;
    import "../helpers/BalancerErrors.sol";
    // Based on the EnumerableSet library from OpenZeppelin contracts, altered to remove the base private functions that
    // work on bytes32, replacing them with a native implementation for address values, to reduce bytecode size and runtime
    // costs.
    // The `unchecked_at` function was also added, which allows for more gas efficient data reads in some scenarios.
    /**
     * @dev Library for managing
     * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
     * types.
     *
     * Sets have the following properties:
     *
     * - Elements are added, removed, and checked for existence in constant time
     * (O(1)).
     * - Elements are enumerated in O(n). No guarantees are made on the ordering.
     *
     * ```
     * contract Example {
     *     // Add the library methods
     *     using EnumerableSet for EnumerableSet.AddressSet;
     *
     *     // Declare a set state variable
     *     EnumerableSet.AddressSet private mySet;
     * }
     * ```
     *
     * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
     * and `uint256` (`UintSet`) are supported.
     */
    library EnumerableSet {
        // The original OpenZeppelin implementation uses a generic Set type with bytes32 values: this was replaced with
        // AddressSet, which uses address keys natively, resulting in more dense bytecode.
        struct AddressSet {
            // Storage of set values
            address[] _values;
            // Position of the value in the `values` array, plus 1 because index 0
            // means a value is not in the set.
            mapping(address => uint256) _indexes;
        }
        /**
         * @dev Add a value to a set. O(1).
         *
         * Returns true if the value was added to the set, that is if it was not
         * already present.
         */
        function add(AddressSet storage set, address value) internal returns (bool) {
            if (!contains(set, value)) {
                set._values.push(value);
                // The value is stored at length-1, but we add 1 to all indexes
                // and use 0 as a sentinel value
                set._indexes[value] = set._values.length;
                return true;
            } else {
                return false;
            }
        }
        /**
         * @dev Removes a value from a set. O(1).
         *
         * Returns true if the value was removed from the set, that is if it was
         * present.
         */
        function remove(AddressSet storage set, address value) internal returns (bool) {
            // We read and store the value's index to prevent multiple reads from the same storage slot
            uint256 valueIndex = set._indexes[value];
            if (valueIndex != 0) {
                // Equivalent to contains(set, value)
                // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
                // the array, and then remove the last element (sometimes called as 'swap and pop').
                // This modifies the order of the array, as noted in {at}.
                uint256 toDeleteIndex = valueIndex - 1;
                uint256 lastIndex = set._values.length - 1;
                // When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs
                // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.
                address lastValue = set._values[lastIndex];
                // Move the last value to the index where the value to delete is
                set._values[toDeleteIndex] = lastValue;
                // Update the index for the moved value
                set._indexes[lastValue] = toDeleteIndex + 1; // All indexes are 1-based
                // Delete the slot where the moved value was stored
                set._values.pop();
                // Delete the index for the deleted slot
                delete set._indexes[value];
                return true;
            } else {
                return false;
            }
        }
        /**
         * @dev Returns true if the value is in the set. O(1).
         */
        function contains(AddressSet storage set, address value) internal view returns (bool) {
            return set._indexes[value] != 0;
        }
        /**
         * @dev Returns the number of values on the set. O(1).
         */
        function length(AddressSet storage set) internal view returns (uint256) {
            return set._values.length;
        }
        /**
         * @dev Returns the value stored at position `index` in the set. O(1).
         *
         * Note that there are no guarantees on the ordering of values inside the
         * array, and it may change when more values are added or removed.
         *
         * Requirements:
         *
         * - `index` must be strictly less than {length}.
         */
        function at(AddressSet storage set, uint256 index) internal view returns (address) {
            _require(set._values.length > index, Errors.OUT_OF_BOUNDS);
            return unchecked_at(set, index);
        }
        /**
         * @dev Same as {at}, except this doesn't revert if `index` it outside of the set (i.e. if it is equal or larger
         * than {length}). O(1).
         *
         * This function performs one less storage read than {at}, but should only be used when `index` is known to be
         * within bounds.
         */
        function unchecked_at(AddressSet storage set, uint256 index) internal view returns (address) {
            return set._values[index];
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.7.0;
    import "../helpers/BalancerErrors.sol";
    /**
     * @dev Wrappers over Solidity's uintXX/intXX casting operators with added overflow
     * checks.
     *
     * Downcasting from uint256/int256 in Solidity does not revert on overflow. This can
     * easily result in undesired exploitation or bugs, since developers usually
     * assume that overflows raise errors. `SafeCast` restores this intuition by
     * reverting the transaction when such an operation overflows.
     *
     * Using this library instead of the unchecked operations eliminates an entire
     * class of bugs, so it's recommended to use it always.
     *
     * Can be combined with {SafeMath} and {SignedSafeMath} to extend it to smaller types, by performing
     * all math on `uint256` and `int256` and then downcasting.
     */
    library SafeCast {
        /**
         * @dev Converts an unsigned uint256 into a signed int256.
         *
         * Requirements:
         *
         * - input must be less than or equal to maxInt256.
         */
        function toInt256(uint256 value) internal pure returns (int256) {
            _require(value < 2**255, Errors.SAFE_CAST_VALUE_CANT_FIT_INT256);
            return int256(value);
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "../lib/math/Math.sol";
    import "../lib/helpers/BalancerErrors.sol";
    import "../lib/helpers/InputHelpers.sol";
    import "../lib/openzeppelin/IERC20.sol";
    import "../lib/openzeppelin/ReentrancyGuard.sol";
    import "../lib/openzeppelin/SafeERC20.sol";
    import "./Fees.sol";
    import "./PoolTokens.sol";
    import "./UserBalance.sol";
    import "./interfaces/IBasePool.sol";
    /**
     * @dev Stores the Asset Managers (by Pool and token), and implements the top level Asset Manager and Pool interfaces,
     * such as registering and deregistering tokens, joining and exiting Pools, and informational functions like `getPool`
     * and `getPoolTokens`, delegating to specialization-specific functions as needed.
     *
     * `managePoolBalance` handles all Asset Manager interactions.
     */
    abstract contract PoolBalances is Fees, ReentrancyGuard, PoolTokens, UserBalance {
        using Math for uint256;
        using SafeERC20 for IERC20;
        using BalanceAllocation for bytes32;
        using BalanceAllocation for bytes32[];
        function joinPool(
            bytes32 poolId,
            address sender,
            address recipient,
            JoinPoolRequest memory request
        ) external payable override whenNotPaused {
            // This function doesn't have the nonReentrant modifier: it is applied to `_joinOrExit` instead.
            // Note that `recipient` is not actually payable in the context of a join - we cast it because we handle both
            // joins and exits at once.
            _joinOrExit(PoolBalanceChangeKind.JOIN, poolId, sender, payable(recipient), _toPoolBalanceChange(request));
        }
        function exitPool(
            bytes32 poolId,
            address sender,
            address payable recipient,
            ExitPoolRequest memory request
        ) external override {
            // This function doesn't have the nonReentrant modifier: it is applied to `_joinOrExit` instead.
            _joinOrExit(PoolBalanceChangeKind.EXIT, poolId, sender, recipient, _toPoolBalanceChange(request));
        }
        // This has the exact same layout as JoinPoolRequest and ExitPoolRequest, except the `maxAmountsIn` and
        // `minAmountsOut` are called `limits`. Internally we use this struct for both since these two functions are quite
        // similar, but expose the others to callers for clarity.
        struct PoolBalanceChange {
            IAsset[] assets;
            uint256[] limits;
            bytes userData;
            bool useInternalBalance;
        }
        /**
         * @dev Converts a JoinPoolRequest into a PoolBalanceChange, with no runtime cost.
         */
        function _toPoolBalanceChange(JoinPoolRequest memory request)
            private
            pure
            returns (PoolBalanceChange memory change)
        {
            // solhint-disable-next-line no-inline-assembly
            assembly {
                change := request
            }
        }
        /**
         * @dev Converts an ExitPoolRequest into a PoolBalanceChange, with no runtime cost.
         */
        function _toPoolBalanceChange(ExitPoolRequest memory request)
            private
            pure
            returns (PoolBalanceChange memory change)
        {
            // solhint-disable-next-line no-inline-assembly
            assembly {
                change := request
            }
        }
        /**
         * @dev Implements both `joinPool` and `exitPool`, based on `kind`.
         */
        function _joinOrExit(
            PoolBalanceChangeKind kind,
            bytes32 poolId,
            address sender,
            address payable recipient,
            PoolBalanceChange memory change
        ) private nonReentrant withRegisteredPool(poolId) authenticateFor(sender) {
            // This function uses a large number of stack variables (poolId, sender and recipient, balances, amounts, fees,
            // etc.), which leads to 'stack too deep' issues. It relies on private functions with seemingly arbitrary
            // interfaces to work around this limitation.
            InputHelpers.ensureInputLengthMatch(change.assets.length, change.limits.length);
            // We first check that the caller passed the Pool's registered tokens in the correct order, and retrieve the
            // current balance for each.
            IERC20[] memory tokens = _translateToIERC20(change.assets);
            bytes32[] memory balances = _validateTokensAndGetBalances(poolId, tokens);
            // The bulk of the work is done here: the corresponding Pool hook is called, its final balances are computed,
            // assets are transferred, and fees are paid.
            (
                bytes32[] memory finalBalances,
                uint256[] memory amountsInOrOut,
                uint256[] memory paidProtocolSwapFeeAmounts
            ) = _callPoolBalanceChange(kind, poolId, sender, recipient, change, balances);
            // All that remains is storing the new Pool balances.
            PoolSpecialization specialization = _getPoolSpecialization(poolId);
            if (specialization == PoolSpecialization.TWO_TOKEN) {
                _setTwoTokenPoolCashBalances(poolId, tokens[0], finalBalances[0], tokens[1], finalBalances[1]);
            } else if (specialization == PoolSpecialization.MINIMAL_SWAP_INFO) {
                _setMinimalSwapInfoPoolBalances(poolId, tokens, finalBalances);
            } else {
                // PoolSpecialization.GENERAL
                _setGeneralPoolBalances(poolId, finalBalances);
            }
            bool positive = kind == PoolBalanceChangeKind.JOIN; // Amounts in are positive, out are negative
            emit PoolBalanceChanged(
                poolId,
                sender,
                tokens,
                // We can unsafely cast to int256 because balances are actually stored as uint112
                _unsafeCastToInt256(amountsInOrOut, positive),
                paidProtocolSwapFeeAmounts
            );
        }
        /**
         * @dev Calls the corresponding Pool hook to get the amounts in/out plus protocol fee amounts, and performs the
         * associated token transfers and fee payments, returning the Pool's final balances.
         */
        function _callPoolBalanceChange(
            PoolBalanceChangeKind kind,
            bytes32 poolId,
            address sender,
            address payable recipient,
            PoolBalanceChange memory change,
            bytes32[] memory balances
        )
            private
            returns (
                bytes32[] memory finalBalances,
                uint256[] memory amountsInOrOut,
                uint256[] memory dueProtocolFeeAmounts
            )
        {
            (uint256[] memory totalBalances, uint256 lastChangeBlock) = balances.totalsAndLastChangeBlock();
            IBasePool pool = IBasePool(_getPoolAddress(poolId));
            (amountsInOrOut, dueProtocolFeeAmounts) = kind == PoolBalanceChangeKind.JOIN
                ? pool.onJoinPool(
                    poolId,
                    sender,
                    recipient,
                    totalBalances,
                    lastChangeBlock,
                    _getProtocolSwapFeePercentage(),
                    change.userData
                )
                : pool.onExitPool(
                    poolId,
                    sender,
                    recipient,
                    totalBalances,
                    lastChangeBlock,
                    _getProtocolSwapFeePercentage(),
                    change.userData
                );
            InputHelpers.ensureInputLengthMatch(balances.length, amountsInOrOut.length, dueProtocolFeeAmounts.length);
            // The Vault ignores the `recipient` in joins and the `sender` in exits: it is up to the Pool to keep track of
            // their participation.
            finalBalances = kind == PoolBalanceChangeKind.JOIN
                ? _processJoinPoolTransfers(sender, change, balances, amountsInOrOut, dueProtocolFeeAmounts)
                : _processExitPoolTransfers(recipient, change, balances, amountsInOrOut, dueProtocolFeeAmounts);
        }
        /**
         * @dev Transfers `amountsIn` from `sender`, checking that they are within their accepted limits, and pays
         * accumulated protocol swap fees.
         *
         * Returns the Pool's final balances, which are the current balances plus `amountsIn` minus accumulated protocol
         * swap fees.
         */
        function _processJoinPoolTransfers(
            address sender,
            PoolBalanceChange memory change,
            bytes32[] memory balances,
            uint256[] memory amountsIn,
            uint256[] memory dueProtocolFeeAmounts
        ) private returns (bytes32[] memory finalBalances) {
            // We need to track how much of the received ETH was used and wrapped into WETH to return any excess.
            uint256 wrappedEth = 0;
            finalBalances = new bytes32[](balances.length);
            for (uint256 i = 0; i < change.assets.length; ++i) {
                uint256 amountIn = amountsIn[i];
                _require(amountIn <= change.limits[i], Errors.JOIN_ABOVE_MAX);
                // Receive assets from the sender - possibly from Internal Balance.
                IAsset asset = change.assets[i];
                _receiveAsset(asset, amountIn, sender, change.useInternalBalance);
                if (_isETH(asset)) {
                    wrappedEth = wrappedEth.add(amountIn);
                }
                uint256 feeAmount = dueProtocolFeeAmounts[i];
                _payFeeAmount(_translateToIERC20(asset), feeAmount);
                // Compute the new Pool balances. Note that the fee amount might be larger than `amountIn`,
                // resulting in an overall decrease of the Pool's balance for a token.
                finalBalances[i] = (amountIn >= feeAmount) // This lets us skip checked arithmetic
                    ? balances[i].increaseCash(amountIn - feeAmount)
                    : balances[i].decreaseCash(feeAmount - amountIn);
            }
            // Handle any used and remaining ETH.
            _handleRemainingEth(wrappedEth);
        }
        /**
         * @dev Transfers `amountsOut` to `recipient`, checking that they are within their accepted limits, and pays
         * accumulated protocol swap fees from the Pool.
         *
         * Returns the Pool's final balances, which are the current `balances` minus `amountsOut` and fees paid
         * (`dueProtocolFeeAmounts`).
         */
        function _processExitPoolTransfers(
            address payable recipient,
            PoolBalanceChange memory change,
            bytes32[] memory balances,
            uint256[] memory amountsOut,
            uint256[] memory dueProtocolFeeAmounts
        ) private returns (bytes32[] memory finalBalances) {
            finalBalances = new bytes32[](balances.length);
            for (uint256 i = 0; i < change.assets.length; ++i) {
                uint256 amountOut = amountsOut[i];
                _require(amountOut >= change.limits[i], Errors.EXIT_BELOW_MIN);
                // Send tokens to the recipient - possibly to Internal Balance
                IAsset asset = change.assets[i];
                _sendAsset(asset, amountOut, recipient, change.useInternalBalance);
                uint256 feeAmount = dueProtocolFeeAmounts[i];
                _payFeeAmount(_translateToIERC20(asset), feeAmount);
                // Compute the new Pool balances. A Pool's token balance always decreases after an exit (potentially by 0).
                finalBalances[i] = balances[i].decreaseCash(amountOut.add(feeAmount));
            }
        }
        /**
         * @dev Returns the total balance for `poolId`'s `expectedTokens`.
         *
         * `expectedTokens` must exactly equal the token array returned by `getPoolTokens`: both arrays must have the same
         * length, elements and order. Additionally, the Pool must have at least one registered token.
         */
        function _validateTokensAndGetBalances(bytes32 poolId, IERC20[] memory expectedTokens)
            private
            view
            returns (bytes32[] memory)
        {
            (IERC20[] memory actualTokens, bytes32[] memory balances) = _getPoolTokens(poolId);
            InputHelpers.ensureInputLengthMatch(actualTokens.length, expectedTokens.length);
            _require(actualTokens.length > 0, Errors.POOL_NO_TOKENS);
            for (uint256 i = 0; i < actualTokens.length; ++i) {
                _require(actualTokens[i] == expectedTokens[i], Errors.TOKENS_MISMATCH);
            }
            return balances;
        }
        /**
         * @dev Casts an array of uint256 to int256, setting the sign of the result according to the `positive` flag,
         * without checking whether the values fit in the signed 256 bit range.
         */
        function _unsafeCastToInt256(uint256[] memory values, bool positive)
            private
            pure
            returns (int256[] memory signedValues)
        {
            signedValues = new int256[](values.length);
            for (uint256 i = 0; i < values.length; i++) {
                signedValues[i] = positive ? int256(values[i]) : -int256(values[i]);
            }
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "../../lib/openzeppelin/IERC20.sol";
    import "./IVault.sol";
    interface IPoolSwapStructs {
        // This is not really an interface - it just defines common structs used by other interfaces: IGeneralPool and
        // IMinimalSwapInfoPool.
        //
        // This data structure represents a request for a token swap, where `kind` indicates the swap type ('given in' or
        // 'given out') which indicates whether or not the amount sent by the pool is known.
        //
        // The pool receives `tokenIn` and sends `tokenOut`. `amount` is the number of `tokenIn` tokens the pool will take
        // in, or the number of `tokenOut` tokens the Pool will send out, depending on the given swap `kind`.
        //
        // All other fields are not strictly necessary for most swaps, but are provided to support advanced scenarios in
        // some Pools.
        //
        // `poolId` is the ID of the Pool involved in the swap - this is useful for Pool contracts that implement more than
        // one Pool.
        //
        // The meaning of `lastChangeBlock` depends on the Pool specialization:
        //  - Two Token or Minimal Swap Info: the last block in which either `tokenIn` or `tokenOut` changed its total
        //    balance.
        //  - General: the last block in which *any* of the Pool's registered tokens changed its total balance.
        //
        // `from` is the origin address for the funds the Pool receives, and `to` is the destination address
        // where the Pool sends the outgoing tokens.
        //
        // `userData` is extra data provided by the caller - typically a signature from a trusted party.
        struct SwapRequest {
            IVault.SwapKind kind;
            IERC20 tokenIn;
            IERC20 tokenOut;
            uint256 amount;
            // Misc data
            bytes32 poolId;
            uint256 lastChangeBlock;
            address from;
            address to;
            bytes userData;
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "./IBasePool.sol";
    /**
     * @dev IPools with the General specialization setting should implement this interface.
     *
     * This is called by the Vault when a user calls `IVault.swap` or `IVault.batchSwap` to swap with this Pool.
     * Returns the number of tokens the Pool will grant to the user in a 'given in' swap, or that the user will
     * grant to the pool in a 'given out' swap.
     *
     * This can often be implemented by a `view` function, since many pricing algorithms don't need to track state
     * changes in swaps. However, contracts implementing this in non-view functions should check that the caller is
     * indeed the Vault.
     */
    interface IGeneralPool is IBasePool {
        function onSwap(
            SwapRequest memory swapRequest,
            uint256[] memory balances,
            uint256 indexIn,
            uint256 indexOut
        ) external returns (uint256 amount);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "./IBasePool.sol";
    /**
     * @dev Pool contracts with the MinimalSwapInfo or TwoToken specialization settings should implement this interface.
     *
     * This is called by the Vault when a user calls `IVault.swap` or `IVault.batchSwap` to swap with this Pool.
     * Returns the number of tokens the Pool will grant to the user in a 'given in' swap, or that the user will grant
     * to the pool in a 'given out' swap.
     *
     * This can often be implemented by a `view` function, since many pricing algorithms don't need to track state
     * changes in swaps. However, contracts implementing this in non-view functions should check that the caller is
     * indeed the Vault.
     */
    interface IMinimalSwapInfoPool is IBasePool {
        function onSwap(
            SwapRequest memory swapRequest,
            uint256 currentBalanceTokenIn,
            uint256 currentBalanceTokenOut
        ) external returns (uint256 amount);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "../../lib/math/Math.sol";
    // This library is used to create a data structure that represents a token's balance for a Pool. 'cash' is how many
    // tokens the Pool has sitting inside of the Vault. 'managed' is how many tokens were withdrawn from the Vault by the
    // Pool's Asset Manager. 'total' is the sum of these two, and represents the Pool's total token balance, including
    // tokens that are *not* inside of the Vault.
    //
    // 'cash' is updated whenever tokens enter and exit the Vault, while 'managed' is only updated if the reason tokens are
    // moving is due to an Asset Manager action. This is reflected in the different methods available: 'increaseCash'
    // and 'decreaseCash' for swaps and add/remove liquidity events, and 'cashToManaged' and 'managedToCash' for events
    // transferring funds to and from the Asset Manager.
    //
    // The Vault disallows the Pool's 'cash' from becoming negative. In other words, it can never use any tokens that are
    // not inside the Vault.
    //
    // One of the goals of this library is to store the entire token balance in a single storage slot, which is why we use
    // 112 bit unsigned integers for 'cash' and 'managed'. For consistency, we also disallow any combination of 'cash' and
    // 'managed' that yields a 'total' that doesn't fit in 112 bits.
    //
    // The remaining 32 bits of the slot are used to store the most recent block when the total balance changed. This
    // can be used to implement price oracles that are resilient to 'sandwich' attacks.
    //
    // We could use a Solidity struct to pack these three values together in a single storage slot, but unfortunately
    // Solidity only allows for structs to live in either storage, calldata or memory. Because a memory struct still takes
    // up a slot in the stack (to store its memory location), and because the entire balance fits in a single stack slot
    // (two 112 bit values plus the 32 bit block), using memory is strictly less gas performant. Therefore, we do manual
    // packing and unpacking.
    //
    // Since we cannot define new types, we rely on bytes32 to represent these values instead, as it doesn't have any
    // associated arithmetic operations and therefore reduces the chance of misuse.
    library BalanceAllocation {
        using Math for uint256;
        // The 'cash' portion of the balance is stored in the least significant 112 bits of a 256 bit word, while the
        // 'managed' part uses the following 112 bits. The most significant 32 bits are used to store the block
        /**
         * @dev Returns the total amount of Pool tokens, including those that are not currently in the Vault ('managed').
         */
        function total(bytes32 balance) internal pure returns (uint256) {
            // Since 'cash' and 'managed' are 112 bit values, we don't need checked arithmetic. Additionally, `toBalance`
            // ensures that 'total' always fits in 112 bits.
            return cash(balance) + managed(balance);
        }
        /**
         * @dev Returns the amount of Pool tokens currently in the Vault.
         */
        function cash(bytes32 balance) internal pure returns (uint256) {
            uint256 mask = 2**(112) - 1;
            return uint256(balance) & mask;
        }
        /**
         * @dev Returns the amount of Pool tokens that are being managed by an Asset Manager.
         */
        function managed(bytes32 balance) internal pure returns (uint256) {
            uint256 mask = 2**(112) - 1;
            return uint256(balance >> 112) & mask;
        }
        /**
         * @dev Returns the last block when the total balance changed.
         */
        function lastChangeBlock(bytes32 balance) internal pure returns (uint256) {
            uint256 mask = 2**(32) - 1;
            return uint256(balance >> 224) & mask;
        }
        /**
         * @dev Returns the difference in 'managed' between two balances.
         */
        function managedDelta(bytes32 newBalance, bytes32 oldBalance) internal pure returns (int256) {
            // Because `managed` is a 112 bit value, we can safely perform unchecked arithmetic in 256 bits.
            return int256(managed(newBalance)) - int256(managed(oldBalance));
        }
        /**
         * @dev Returns the total balance for each entry in `balances`, as well as the latest block when the total
         * balance of *any* of them last changed.
         */
        function totalsAndLastChangeBlock(bytes32[] memory balances)
            internal
            pure
            returns (
                uint256[] memory results,
                uint256 lastChangeBlock_ // Avoid shadowing
            )
        {
            results = new uint256[](balances.length);
            lastChangeBlock_ = 0;
            for (uint256 i = 0; i < results.length; i++) {
                bytes32 balance = balances[i];
                results[i] = total(balance);
                lastChangeBlock_ = Math.max(lastChangeBlock_, lastChangeBlock(balance));
            }
        }
        /**
         * @dev Returns true if `balance`'s 'total' balance is zero. Costs less gas than computing 'total' and comparing
         * with zero.
         */
        function isZero(bytes32 balance) internal pure returns (bool) {
            // We simply need to check the least significant 224 bytes of the word: the block does not affect this.
            uint256 mask = 2**(224) - 1;
            return (uint256(balance) & mask) == 0;
        }
        /**
         * @dev Returns true if `balance`'s 'total' balance is not zero. Costs less gas than computing 'total' and comparing
         * with zero.
         */
        function isNotZero(bytes32 balance) internal pure returns (bool) {
            return !isZero(balance);
        }
        /**
         * @dev Packs together `cash` and `managed` amounts with a block to create a balance value.
         *
         * For consistency, this also checks that the sum of `cash` and `managed` (`total`) fits in 112 bits.
         */
        function toBalance(
            uint256 _cash,
            uint256 _managed,
            uint256 _blockNumber
        ) internal pure returns (bytes32) {
            uint256 _total = _cash + _managed;
            // Since both 'cash' and 'managed' are positive integers, by checking that their sum ('total') fits in 112 bits
            // we are also indirectly checking that both 'cash' and 'managed' themselves fit in 112 bits.
            _require(_total >= _cash && _total < 2**112, Errors.BALANCE_TOTAL_OVERFLOW);
            // We assume the block fits in 32 bits - this is expected to hold for at least a few decades.
            return _pack(_cash, _managed, _blockNumber);
        }
        /**
         * @dev Increases a Pool's 'cash' (and therefore its 'total'). Called when Pool tokens are sent to the Vault (except
         * for Asset Manager deposits).
         *
         * Updates the last total balance change block, even if `amount` is zero.
         */
        function increaseCash(bytes32 balance, uint256 amount) internal view returns (bytes32) {
            uint256 newCash = cash(balance).add(amount);
            uint256 currentManaged = managed(balance);
            uint256 newLastChangeBlock = block.number;
            return toBalance(newCash, currentManaged, newLastChangeBlock);
        }
        /**
         * @dev Decreases a Pool's 'cash' (and therefore its 'total'). Called when Pool tokens are sent from the Vault
         * (except for Asset Manager withdrawals).
         *
         * Updates the last total balance change block, even if `amount` is zero.
         */
        function decreaseCash(bytes32 balance, uint256 amount) internal view returns (bytes32) {
            uint256 newCash = cash(balance).sub(amount);
            uint256 currentManaged = managed(balance);
            uint256 newLastChangeBlock = block.number;
            return toBalance(newCash, currentManaged, newLastChangeBlock);
        }
        /**
         * @dev Moves 'cash' into 'managed', leaving 'total' unchanged. Called when an Asset Manager withdraws Pool tokens
         * from the Vault.
         */
        function cashToManaged(bytes32 balance, uint256 amount) internal pure returns (bytes32) {
            uint256 newCash = cash(balance).sub(amount);
            uint256 newManaged = managed(balance).add(amount);
            uint256 currentLastChangeBlock = lastChangeBlock(balance);
            return toBalance(newCash, newManaged, currentLastChangeBlock);
        }
        /**
         * @dev Moves 'managed' into 'cash', leaving 'total' unchanged. Called when an Asset Manager deposits Pool tokens
         * into the Vault.
         */
        function managedToCash(bytes32 balance, uint256 amount) internal pure returns (bytes32) {
            uint256 newCash = cash(balance).add(amount);
            uint256 newManaged = managed(balance).sub(amount);
            uint256 currentLastChangeBlock = lastChangeBlock(balance);
            return toBalance(newCash, newManaged, currentLastChangeBlock);
        }
        /**
         * @dev Sets 'managed' balance to an arbitrary value, changing 'total'. Called when the Asset Manager reports
         * profits or losses. It's the Manager's responsibility to provide a meaningful value.
         *
         * Updates the last total balance change block, even if `newManaged` is equal to the current 'managed' value.
         */
        function setManaged(bytes32 balance, uint256 newManaged) internal view returns (bytes32) {
            uint256 currentCash = cash(balance);
            uint256 newLastChangeBlock = block.number;
            return toBalance(currentCash, newManaged, newLastChangeBlock);
        }
        // Alternative mode for Pools with the Two Token specialization setting
        // Instead of storing cash and external for each 'token in' a single storage slot, Two Token Pools store the cash
        // for both tokens in the same slot, and the managed for both in another one. This reduces the gas cost for swaps,
        // because the only slot that needs to be updated is the one with the cash. However, it also means that managing
        // balances is more cumbersome, as both tokens need to be read/written at the same time.
        //
        // The field with both cash balances packed is called sharedCash, and the one with external amounts is called
        // sharedManaged. These two are collectively called the 'shared' balance fields. In both of these, the portion
        // that corresponds to token A is stored in the least significant 112 bits of a 256 bit word, while token B's part
        // uses the next least significant 112 bits.
        //
        // Because only cash is written to during a swap, we store the last total balance change block with the
        // packed cash fields. Typically Pools have a distinct block per token: in the case of Two Token Pools they
        // are the same.
        /**
         * @dev Extracts the part of the balance that corresponds to token A. This function can be used to decode both
         * shared cash and managed balances.
         */
        function _decodeBalanceA(bytes32 sharedBalance) private pure returns (uint256) {
            uint256 mask = 2**(112) - 1;
            return uint256(sharedBalance) & mask;
        }
        /**
         * @dev Extracts the part of the balance that corresponds to token B. This function can be used to decode both
         * shared cash and managed balances.
         */
        function _decodeBalanceB(bytes32 sharedBalance) private pure returns (uint256) {
            uint256 mask = 2**(112) - 1;
            return uint256(sharedBalance >> 112) & mask;
        }
        // To decode the last balance change block, we can simply use the `blockNumber` function.
        /**
         * @dev Unpacks the shared token A and token B cash and managed balances into the balance for token A.
         */
        function fromSharedToBalanceA(bytes32 sharedCash, bytes32 sharedManaged) internal pure returns (bytes32) {
            // Note that we extract the block from the sharedCash field, which is the one that is updated by swaps.
            // Both token A and token B use the same block
            return toBalance(_decodeBalanceA(sharedCash), _decodeBalanceA(sharedManaged), lastChangeBlock(sharedCash));
        }
        /**
         * @dev Unpacks the shared token A and token B cash and managed balances into the balance for token B.
         */
        function fromSharedToBalanceB(bytes32 sharedCash, bytes32 sharedManaged) internal pure returns (bytes32) {
            // Note that we extract the block from the sharedCash field, which is the one that is updated by swaps.
            // Both token A and token B use the same block
            return toBalance(_decodeBalanceB(sharedCash), _decodeBalanceB(sharedManaged), lastChangeBlock(sharedCash));
        }
        /**
         * @dev Returns the sharedCash shared field, given the current balances for token A and token B.
         */
        function toSharedCash(bytes32 tokenABalance, bytes32 tokenBBalance) internal pure returns (bytes32) {
            // Both balances are assigned the same block  Since it is possible a single one of them has changed (for
            // example, in an Asset Manager update), we keep the latest (largest) one.
            uint32 newLastChangeBlock = uint32(Math.max(lastChangeBlock(tokenABalance), lastChangeBlock(tokenBBalance)));
            return _pack(cash(tokenABalance), cash(tokenBBalance), newLastChangeBlock);
        }
        /**
         * @dev Returns the sharedManaged shared field, given the current balances for token A and token B.
         */
        function toSharedManaged(bytes32 tokenABalance, bytes32 tokenBBalance) internal pure returns (bytes32) {
            // We don't bother storing a last change block, as it is read from the shared cash field.
            return _pack(managed(tokenABalance), managed(tokenBBalance), 0);
        }
        // Shared functions
        /**
         * @dev Packs together two uint112 and one uint32 into a bytes32
         */
        function _pack(
            uint256 _leastSignificant,
            uint256 _midSignificant,
            uint256 _mostSignificant
        ) private pure returns (bytes32) {
            return bytes32((_mostSignificant << 224) + (_midSignificant << 112) + _leastSignificant);
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "../lib/helpers/BalancerErrors.sol";
    import "../lib/openzeppelin/ReentrancyGuard.sol";
    import "./AssetManagers.sol";
    import "./PoolRegistry.sol";
    import "./balances/BalanceAllocation.sol";
    abstract contract PoolTokens is ReentrancyGuard, PoolRegistry, AssetManagers {
        using BalanceAllocation for bytes32;
        using BalanceAllocation for bytes32[];
        function registerTokens(
            bytes32 poolId,
            IERC20[] memory tokens,
            address[] memory assetManagers
        ) external override nonReentrant whenNotPaused onlyPool(poolId) {
            InputHelpers.ensureInputLengthMatch(tokens.length, assetManagers.length);
            // Validates token addresses and assigns Asset Managers
            for (uint256 i = 0; i < tokens.length; ++i) {
                IERC20 token = tokens[i];
                _require(token != IERC20(0), Errors.INVALID_TOKEN);
                _poolAssetManagers[poolId][token] = assetManagers[i];
            }
            PoolSpecialization specialization = _getPoolSpecialization(poolId);
            if (specialization == PoolSpecialization.TWO_TOKEN) {
                _require(tokens.length == 2, Errors.TOKENS_LENGTH_MUST_BE_2);
                _registerTwoTokenPoolTokens(poolId, tokens[0], tokens[1]);
            } else if (specialization == PoolSpecialization.MINIMAL_SWAP_INFO) {
                _registerMinimalSwapInfoPoolTokens(poolId, tokens);
            } else {
                // PoolSpecialization.GENERAL
                _registerGeneralPoolTokens(poolId, tokens);
            }
            emit TokensRegistered(poolId, tokens, assetManagers);
        }
        function deregisterTokens(bytes32 poolId, IERC20[] memory tokens)
            external
            override
            nonReentrant
            whenNotPaused
            onlyPool(poolId)
        {
            PoolSpecialization specialization = _getPoolSpecialization(poolId);
            if (specialization == PoolSpecialization.TWO_TOKEN) {
                _require(tokens.length == 2, Errors.TOKENS_LENGTH_MUST_BE_2);
                _deregisterTwoTokenPoolTokens(poolId, tokens[0], tokens[1]);
            } else if (specialization == PoolSpecialization.MINIMAL_SWAP_INFO) {
                _deregisterMinimalSwapInfoPoolTokens(poolId, tokens);
            } else {
                // PoolSpecialization.GENERAL
                _deregisterGeneralPoolTokens(poolId, tokens);
            }
            // The deregister calls above ensure the total token balance is zero. Therefore it is now safe to remove any
            // associated Asset Managers, since they hold no Pool balance.
            for (uint256 i = 0; i < tokens.length; ++i) {
                delete _poolAssetManagers[poolId][tokens[i]];
            }
            emit TokensDeregistered(poolId, tokens);
        }
        function getPoolTokens(bytes32 poolId)
            external
            view
            override
            withRegisteredPool(poolId)
            returns (
                IERC20[] memory tokens,
                uint256[] memory balances,
                uint256 lastChangeBlock
            )
        {
            bytes32[] memory rawBalances;
            (tokens, rawBalances) = _getPoolTokens(poolId);
            (balances, lastChangeBlock) = rawBalances.totalsAndLastChangeBlock();
        }
        function getPoolTokenInfo(bytes32 poolId, IERC20 token)
            external
            view
            override
            withRegisteredPool(poolId)
            returns (
                uint256 cash,
                uint256 managed,
                uint256 lastChangeBlock,
                address assetManager
            )
        {
            bytes32 balance;
            PoolSpecialization specialization = _getPoolSpecialization(poolId);
            if (specialization == PoolSpecialization.TWO_TOKEN) {
                balance = _getTwoTokenPoolBalance(poolId, token);
            } else if (specialization == PoolSpecialization.MINIMAL_SWAP_INFO) {
                balance = _getMinimalSwapInfoPoolBalance(poolId, token);
            } else {
                // PoolSpecialization.GENERAL
                balance = _getGeneralPoolBalance(poolId, token);
            }
            cash = balance.cash();
            managed = balance.managed();
            lastChangeBlock = balance.lastChangeBlock();
            assetManager = _poolAssetManagers[poolId][token];
        }
        /**
         * @dev Returns all of `poolId`'s registered tokens, along with their raw balances.
         */
        function _getPoolTokens(bytes32 poolId) internal view returns (IERC20[] memory tokens, bytes32[] memory balances) {
            PoolSpecialization specialization = _getPoolSpecialization(poolId);
            if (specialization == PoolSpecialization.TWO_TOKEN) {
                return _getTwoTokenPoolTokens(poolId);
            } else if (specialization == PoolSpecialization.MINIMAL_SWAP_INFO) {
                return _getMinimalSwapInfoPoolTokens(poolId);
            } else {
                // PoolSpecialization.GENERAL
                return _getGeneralPoolTokens(poolId);
            }
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "../lib/helpers/BalancerErrors.sol";
    import "../lib/math/Math.sol";
    import "../lib/openzeppelin/IERC20.sol";
    import "../lib/openzeppelin/ReentrancyGuard.sol";
    import "../lib/openzeppelin/SafeCast.sol";
    import "../lib/openzeppelin/SafeERC20.sol";
    import "./AssetTransfersHandler.sol";
    import "./VaultAuthorization.sol";
    /**
     * Implement User Balance interactions, which combine Internal Balance and using the Vault's ERC20 allowance.
     *
     * Users can deposit tokens into the Vault, where they are allocated to their Internal Balance, and later
     * transferred or withdrawn. It can also be used as a source of tokens when joining Pools, as a destination
     * when exiting them, and as either when performing swaps. This usage of Internal Balance results in greatly reduced
     * gas costs when compared to relying on plain ERC20 transfers, leading to large savings for frequent users.
     *
     * Internal Balance management features batching, which means a single contract call can be used to perform multiple
     * operations of different kinds, with different senders and recipients, at once.
     */
    abstract contract UserBalance is ReentrancyGuard, AssetTransfersHandler, VaultAuthorization {
        using Math for uint256;
        using SafeCast for uint256;
        using SafeERC20 for IERC20;
        // Internal Balance for each token, for each account.
        mapping(address => mapping(IERC20 => uint256)) private _internalTokenBalance;
        function getInternalBalance(address user, IERC20[] memory tokens)
            external
            view
            override
            returns (uint256[] memory balances)
        {
            balances = new uint256[](tokens.length);
            for (uint256 i = 0; i < tokens.length; i++) {
                balances[i] = _getInternalBalance(user, tokens[i]);
            }
        }
        function manageUserBalance(UserBalanceOp[] memory ops) external payable override nonReentrant {
            // We need to track how much of the received ETH was used and wrapped into WETH to return any excess.
            uint256 ethWrapped = 0;
            // Cache for these checks so we only perform them once (if at all).
            bool checkedCallerIsRelayer = false;
            bool checkedNotPaused = false;
            for (uint256 i = 0; i < ops.length; i++) {
                UserBalanceOpKind kind;
                IAsset asset;
                uint256 amount;
                address sender;
                address payable recipient;
                // This destructuring by calling `_validateUserBalanceOp` seems odd, but results in reduced bytecode size.
                (kind, asset, amount, sender, recipient, checkedCallerIsRelayer) = _validateUserBalanceOp(
                    ops[i],
                    checkedCallerIsRelayer
                );
                if (kind == UserBalanceOpKind.WITHDRAW_INTERNAL) {
                    // Internal Balance withdrawals can always be performed by an authorized account.
                    _withdrawFromInternalBalance(asset, sender, recipient, amount);
                } else {
                    // All other operations are blocked if the contract is paused.
                    // We cache the result of the pause check and skip it for other operations in this same transaction
                    // (if any).
                    if (!checkedNotPaused) {
                        _ensureNotPaused();
                        checkedNotPaused = true;
                    }
                    if (kind == UserBalanceOpKind.DEPOSIT_INTERNAL) {
                        _depositToInternalBalance(asset, sender, recipient, amount);
                        // Keep track of all ETH wrapped into WETH as part of a deposit.
                        if (_isETH(asset)) {
                            ethWrapped = ethWrapped.add(amount);
                        }
                    } else {
                        // Transfers don't support ETH.
                        _require(!_isETH(asset), Errors.CANNOT_USE_ETH_SENTINEL);
                        IERC20 token = _asIERC20(asset);
                        if (kind == UserBalanceOpKind.TRANSFER_INTERNAL) {
                            _transferInternalBalance(token, sender, recipient, amount);
                        } else {
                            // TRANSFER_EXTERNAL
                            _transferToExternalBalance(token, sender, recipient, amount);
                        }
                    }
                }
            }
            // Handle any remaining ETH.
            _handleRemainingEth(ethWrapped);
        }
        function _depositToInternalBalance(
            IAsset asset,
            address sender,
            address recipient,
            uint256 amount
        ) private {
            _increaseInternalBalance(recipient, _translateToIERC20(asset), amount);
            _receiveAsset(asset, amount, sender, false);
        }
        function _withdrawFromInternalBalance(
            IAsset asset,
            address sender,
            address payable recipient,
            uint256 amount
        ) private {
            // A partial decrease of Internal Balance is disallowed: `sender` must have the full `amount`.
            _decreaseInternalBalance(sender, _translateToIERC20(asset), amount, false);
            _sendAsset(asset, amount, recipient, false);
        }
        function _transferInternalBalance(
            IERC20 token,
            address sender,
            address recipient,
            uint256 amount
        ) private {
            // A partial decrease of Internal Balance is disallowed: `sender` must have the full `amount`.
            _decreaseInternalBalance(sender, token, amount, false);
            _increaseInternalBalance(recipient, token, amount);
        }
        function _transferToExternalBalance(
            IERC20 token,
            address sender,
            address recipient,
            uint256 amount
        ) private {
            if (amount > 0) {
                token.safeTransferFrom(sender, recipient, amount);
                emit ExternalBalanceTransfer(token, sender, recipient, amount);
            }
        }
        /**
         * @dev Increases `account`'s Internal Balance for `token` by `amount`.
         */
        function _increaseInternalBalance(
            address account,
            IERC20 token,
            uint256 amount
        ) internal override {
            uint256 currentBalance = _getInternalBalance(account, token);
            uint256 newBalance = currentBalance.add(amount);
            _setInternalBalance(account, token, newBalance, amount.toInt256());
        }
        /**
         * @dev Decreases `account`'s Internal Balance for `token` by `amount`. If `allowPartial` is true, this function
         * doesn't revert if `account` doesn't have enough balance, and sets it to zero and returns the deducted amount
         * instead.
         */
        function _decreaseInternalBalance(
            address account,
            IERC20 token,
            uint256 amount,
            bool allowPartial
        ) internal override returns (uint256 deducted) {
            uint256 currentBalance = _getInternalBalance(account, token);
            _require(allowPartial || (currentBalance >= amount), Errors.INSUFFICIENT_INTERNAL_BALANCE);
            deducted = Math.min(currentBalance, amount);
            // By construction, `deducted` is lower or equal to `currentBalance`, so we don't need to use checked
            // arithmetic.
            uint256 newBalance = currentBalance - deducted;
            _setInternalBalance(account, token, newBalance, -(deducted.toInt256()));
        }
        /**
         * @dev Sets `account`'s Internal Balance for `token` to `newBalance`.
         *
         * Emits an `InternalBalanceChanged` event. This event includes `delta`, which is the amount the balance increased
         * (if positive) or decreased (if negative). To avoid reading the current balance in order to compute the delta,
         * this function relies on the caller providing it directly.
         */
        function _setInternalBalance(
            address account,
            IERC20 token,
            uint256 newBalance,
            int256 delta
        ) private {
            _internalTokenBalance[account][token] = newBalance;
            emit InternalBalanceChanged(account, token, delta);
        }
        /**
         * @dev Returns `account`'s Internal Balance for `token`.
         */
        function _getInternalBalance(address account, IERC20 token) internal view returns (uint256) {
            return _internalTokenBalance[account][token];
        }
        /**
         * @dev Destructures a User Balance operation, validating that the contract caller is allowed to perform it.
         */
        function _validateUserBalanceOp(UserBalanceOp memory op, bool checkedCallerIsRelayer)
            private
            view
            returns (
                UserBalanceOpKind,
                IAsset,
                uint256,
                address,
                address payable,
                bool
            )
        {
            // The only argument we need to validate is `sender`, which can only be either the contract caller, or a
            // relayer approved by `sender`.
            address sender = op.sender;
            if (sender != msg.sender) {
                // We need to check both that the contract caller is a relayer, and that `sender` approved them.
                // Because the relayer check is global (i.e. independent of `sender`), we cache that result and skip it for
                // other operations in this same transaction (if any).
                if (!checkedCallerIsRelayer) {
                    _authenticateCaller();
                    checkedCallerIsRelayer = true;
                }
                _require(_hasApprovedRelayer(sender, msg.sender), Errors.USER_DOESNT_ALLOW_RELAYER);
            }
            return (op.kind, op.asset, op.amount, sender, op.recipient, checkedCallerIsRelayer);
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "./IVault.sol";
    import "./IPoolSwapStructs.sol";
    /**
     * @dev Interface for adding and removing liquidity that all Pool contracts should implement. Note that this is not
     * the complete Pool contract interface, as it is missing the swap hooks. Pool contracts should also inherit from
     * either IGeneralPool or IMinimalSwapInfoPool
     */
    interface IBasePool is IPoolSwapStructs {
        /**
         * @dev Called by the Vault when a user calls `IVault.joinPool` to add liquidity to this Pool. Returns how many of
         * each registered token the user should provide, as well as the amount of protocol fees the Pool owes to the Vault.
         * The Vault will then take tokens from `sender` and add them to the Pool's balances, as well as collect
         * the reported amount in protocol fees, which the pool should calculate based on `protocolSwapFeePercentage`.
         *
         * Protocol fees are reported and charged on join events so that the Pool is free of debt whenever new users join.
         *
         * `sender` is the account performing the join (from which tokens will be withdrawn), and `recipient` is the account
         * designated to receive any benefits (typically pool shares). `currentBalances` contains the total balances
         * for each token the Pool registered in the Vault, in the same order that `IVault.getPoolTokens` would return.
         *
         * `lastChangeBlock` is the last block in which *any* of the Pool's registered tokens last changed its total
         * balance.
         *
         * `userData` contains any pool-specific instructions needed to perform the calculations, such as the type of
         * join (e.g., proportional given an amount of pool shares, single-asset, multi-asset, etc.)
         *
         * Contracts implementing this function should check that the caller is indeed the Vault before performing any
         * state-changing operations, such as minting pool shares.
         */
        function onJoinPool(
            bytes32 poolId,
            address sender,
            address recipient,
            uint256[] memory balances,
            uint256 lastChangeBlock,
            uint256 protocolSwapFeePercentage,
            bytes memory userData
        ) external returns (uint256[] memory amountsIn, uint256[] memory dueProtocolFeeAmounts);
        /**
         * @dev Called by the Vault when a user calls `IVault.exitPool` to remove liquidity from this Pool. Returns how many
         * tokens the Vault should deduct from the Pool's balances, as well as the amount of protocol fees the Pool owes
         * to the Vault. The Vault will then take tokens from the Pool's balances and send them to `recipient`,
         * as well as collect the reported amount in protocol fees, which the Pool should calculate based on
         * `protocolSwapFeePercentage`.
         *
         * Protocol fees are charged on exit events to guarantee that users exiting the Pool have paid their share.
         *
         * `sender` is the account performing the exit (typically the pool shareholder), and `recipient` is the account
         * to which the Vault will send the proceeds. `currentBalances` contains the total token balances for each token
         * the Pool registered in the Vault, in the same order that `IVault.getPoolTokens` would return.
         *
         * `lastChangeBlock` is the last block in which *any* of the Pool's registered tokens last changed its total
         * balance.
         *
         * `userData` contains any pool-specific instructions needed to perform the calculations, such as the type of
         * exit (e.g., proportional given an amount of pool shares, single-asset, multi-asset, etc.)
         *
         * Contracts implementing this function should check that the caller is indeed the Vault before performing any
         * state-changing operations, such as burning pool shares.
         */
        function onExitPool(
            bytes32 poolId,
            address sender,
            address recipient,
            uint256[] memory balances,
            uint256 lastChangeBlock,
            uint256 protocolSwapFeePercentage,
            bytes memory userData
        ) external returns (uint256[] memory amountsOut, uint256[] memory dueProtocolFeeAmounts);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "../lib/math/Math.sol";
    import "../lib/helpers/BalancerErrors.sol";
    import "../lib/helpers/InputHelpers.sol";
    import "../lib/openzeppelin/IERC20.sol";
    import "../lib/openzeppelin/SafeERC20.sol";
    import "../lib/openzeppelin/ReentrancyGuard.sol";
    import "./UserBalance.sol";
    import "./balances/BalanceAllocation.sol";
    import "./balances/GeneralPoolsBalance.sol";
    import "./balances/MinimalSwapInfoPoolsBalance.sol";
    import "./balances/TwoTokenPoolsBalance.sol";
    abstract contract AssetManagers is
        ReentrancyGuard,
        GeneralPoolsBalance,
        MinimalSwapInfoPoolsBalance,
        TwoTokenPoolsBalance
    {
        using Math for uint256;
        using SafeERC20 for IERC20;
        // Stores the Asset Manager for each token of each Pool.
        mapping(bytes32 => mapping(IERC20 => address)) internal _poolAssetManagers;
        function managePoolBalance(PoolBalanceOp[] memory ops) external override nonReentrant whenNotPaused {
            // This variable could be declared inside the loop, but that causes the compiler to allocate memory on each
            // loop iteration, increasing gas costs.
            PoolBalanceOp memory op;
            for (uint256 i = 0; i < ops.length; ++i) {
                // By indexing the array only once, we don't spend extra gas in the same bounds check.
                op = ops[i];
                bytes32 poolId = op.poolId;
                _ensureRegisteredPool(poolId);
                IERC20 token = op.token;
                _require(_isTokenRegistered(poolId, token), Errors.TOKEN_NOT_REGISTERED);
                _require(_poolAssetManagers[poolId][token] == msg.sender, Errors.SENDER_NOT_ASSET_MANAGER);
                PoolBalanceOpKind kind = op.kind;
                uint256 amount = op.amount;
                (int256 cashDelta, int256 managedDelta) = _performPoolManagementOperation(kind, poolId, token, amount);
                emit PoolBalanceManaged(poolId, msg.sender, token, cashDelta, managedDelta);
            }
        }
        /**
         * @dev Performs the `kind` Asset Manager operation on a Pool.
         *
         * Withdrawals will transfer `amount` tokens to the caller, deposits will transfer `amount` tokens from the caller,
         * and updates will set the managed balance to `amount`.
         *
         * Returns a tuple with the 'cash' and 'managed' balance deltas as a result of this call.
         */
        function _performPoolManagementOperation(
            PoolBalanceOpKind kind,
            bytes32 poolId,
            IERC20 token,
            uint256 amount
        ) private returns (int256, int256) {
            PoolSpecialization specialization = _getPoolSpecialization(poolId);
            if (kind == PoolBalanceOpKind.WITHDRAW) {
                return _withdrawPoolBalance(poolId, specialization, token, amount);
            } else if (kind == PoolBalanceOpKind.DEPOSIT) {
                return _depositPoolBalance(poolId, specialization, token, amount);
            } else {
                // PoolBalanceOpKind.UPDATE
                return _updateManagedBalance(poolId, specialization, token, amount);
            }
        }
        /**
         * @dev Moves `amount` tokens from a Pool's 'cash' to 'managed' balance, and transfers them to the caller.
         *
         * Returns the 'cash' and 'managed' balance deltas as a result of this call, which will be complementary.
         */
        function _withdrawPoolBalance(
            bytes32 poolId,
            PoolSpecialization specialization,
            IERC20 token,
            uint256 amount
        ) private returns (int256 cashDelta, int256 managedDelta) {
            if (specialization == PoolSpecialization.TWO_TOKEN) {
                _twoTokenPoolCashToManaged(poolId, token, amount);
            } else if (specialization == PoolSpecialization.MINIMAL_SWAP_INFO) {
                _minimalSwapInfoPoolCashToManaged(poolId, token, amount);
            } else {
                // PoolSpecialization.GENERAL
                _generalPoolCashToManaged(poolId, token, amount);
            }
            if (amount > 0) {
                token.safeTransfer(msg.sender, amount);
            }
            // Since 'cash' and 'managed' are stored as uint112, `amount` is guaranteed to also fit in 112 bits. It will
            // therefore always fit in a 256 bit integer.
            cashDelta = int256(-amount);
            managedDelta = int256(amount);
        }
        /**
         * @dev Moves `amount` tokens from a Pool's 'managed' to 'cash' balance, and transfers them from the caller.
         *
         * Returns the 'cash' and 'managed' balance deltas as a result of this call, which will be complementary.
         */
        function _depositPoolBalance(
            bytes32 poolId,
            PoolSpecialization specialization,
            IERC20 token,
            uint256 amount
        ) private returns (int256 cashDelta, int256 managedDelta) {
            if (specialization == PoolSpecialization.TWO_TOKEN) {
                _twoTokenPoolManagedToCash(poolId, token, amount);
            } else if (specialization == PoolSpecialization.MINIMAL_SWAP_INFO) {
                _minimalSwapInfoPoolManagedToCash(poolId, token, amount);
            } else {
                // PoolSpecialization.GENERAL
                _generalPoolManagedToCash(poolId, token, amount);
            }
            if (amount > 0) {
                token.safeTransferFrom(msg.sender, address(this), amount);
            }
            // Since 'cash' and 'managed' are stored as uint112, `amount` is guaranteed to also fit in 112 bits. It will
            // therefore always fit in a 256 bit integer.
            cashDelta = int256(amount);
            managedDelta = int256(-amount);
        }
        /**
         * @dev Sets a Pool's 'managed' balance to `amount`.
         *
         * Returns the 'cash' and 'managed' balance deltas as a result of this call (the 'cash' delta will always be zero).
         */
        function _updateManagedBalance(
            bytes32 poolId,
            PoolSpecialization specialization,
            IERC20 token,
            uint256 amount
        ) private returns (int256 cashDelta, int256 managedDelta) {
            if (specialization == PoolSpecialization.TWO_TOKEN) {
                managedDelta = _setTwoTokenPoolManagedBalance(poolId, token, amount);
            } else if (specialization == PoolSpecialization.MINIMAL_SWAP_INFO) {
                managedDelta = _setMinimalSwapInfoPoolManagedBalance(poolId, token, amount);
            } else {
                // PoolSpecialization.GENERAL
                managedDelta = _setGeneralPoolManagedBalance(poolId, token, amount);
            }
            cashDelta = 0;
        }
        /**
         * @dev Returns true if `token` is registered for `poolId`.
         */
        function _isTokenRegistered(bytes32 poolId, IERC20 token) private view returns (bool) {
            PoolSpecialization specialization = _getPoolSpecialization(poolId);
            if (specialization == PoolSpecialization.TWO_TOKEN) {
                return _isTwoTokenPoolTokenRegistered(poolId, token);
            } else if (specialization == PoolSpecialization.MINIMAL_SWAP_INFO) {
                return _isMinimalSwapInfoPoolTokenRegistered(poolId, token);
            } else {
                // PoolSpecialization.GENERAL
                return _isGeneralPoolTokenRegistered(poolId, token);
            }
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "../lib/helpers/BalancerErrors.sol";
    import "../lib/openzeppelin/ReentrancyGuard.sol";
    import "./VaultAuthorization.sol";
    /**
     * @dev Maintains the Pool ID data structure, implements Pool ID creation and registration, and defines useful modifiers
     * and helper functions for ensuring correct behavior when working with Pools.
     */
    abstract contract PoolRegistry is ReentrancyGuard, VaultAuthorization {
        // Each pool is represented by their unique Pool ID. We use `bytes32` for them, for lack of a way to define new
        // types.
        mapping(bytes32 => bool) private _isPoolRegistered;
        // We keep an increasing nonce to make Pool IDs unique. It is interpreted as a `uint80`, but storing it as a
        // `uint256` results in reduced bytecode on reads and writes due to the lack of masking.
        uint256 private _nextPoolNonce;
        /**
         * @dev Reverts unless `poolId` corresponds to a registered Pool.
         */
        modifier withRegisteredPool(bytes32 poolId) {
            _ensureRegisteredPool(poolId);
            _;
        }
        /**
         * @dev Reverts unless `poolId` corresponds to a registered Pool, and the caller is the Pool's contract.
         */
        modifier onlyPool(bytes32 poolId) {
            _ensurePoolIsSender(poolId);
            _;
        }
        /**
         * @dev Reverts unless `poolId` corresponds to a registered Pool.
         */
        function _ensureRegisteredPool(bytes32 poolId) internal view {
            _require(_isPoolRegistered[poolId], Errors.INVALID_POOL_ID);
        }
        /**
         * @dev Reverts unless `poolId` corresponds to a registered Pool, and the caller is the Pool's contract.
         */
        function _ensurePoolIsSender(bytes32 poolId) private view {
            _ensureRegisteredPool(poolId);
            _require(msg.sender == _getPoolAddress(poolId), Errors.CALLER_NOT_POOL);
        }
        function registerPool(PoolSpecialization specialization)
            external
            override
            nonReentrant
            whenNotPaused
            returns (bytes32)
        {
            // Each Pool is assigned a unique ID based on an incrementing nonce. This assumes there will never be more than
            // 2**80 Pools, and the nonce will not overflow.
            bytes32 poolId = _toPoolId(msg.sender, specialization, uint80(_nextPoolNonce));
            _require(!_isPoolRegistered[poolId], Errors.INVALID_POOL_ID); // Should never happen as Pool IDs are unique.
            _isPoolRegistered[poolId] = true;
            _nextPoolNonce += 1;
            // Note that msg.sender is the pool's contract
            emit PoolRegistered(poolId, msg.sender, specialization);
            return poolId;
        }
        function getPool(bytes32 poolId)
            external
            view
            override
            withRegisteredPool(poolId)
            returns (address, PoolSpecialization)
        {
            return (_getPoolAddress(poolId), _getPoolSpecialization(poolId));
        }
        /**
         * @dev Creates a Pool ID.
         *
         * These are deterministically created by packing the Pool's contract address and its specialization setting into
         * the ID. This saves gas by making this data easily retrievable from a Pool ID with no storage accesses.
         *
         * Since a single contract can register multiple Pools, a unique nonce must be provided to ensure Pool IDs are
         * unique.
         *
         * Pool IDs have the following layout:
         * | 20 bytes pool contract address | 2 bytes specialization setting | 10 bytes nonce |
         * MSB                                                                              LSB
         *
         * 2 bytes for the specialization setting is a bit overkill: there only three of them, which means two bits would
         * suffice. However, there's nothing else of interest to store in this extra space.
         */
        function _toPoolId(
            address pool,
            PoolSpecialization specialization,
            uint80 nonce
        ) internal pure returns (bytes32) {
            bytes32 serialized;
            serialized |= bytes32(uint256(nonce));
            serialized |= bytes32(uint256(specialization)) << (10 * 8);
            serialized |= bytes32(uint256(pool)) << (12 * 8);
            return serialized;
        }
        /**
         * @dev Returns the address of a Pool's contract.
         *
         * Due to how Pool IDs are created, this is done with no storage accesses and costs little gas.
         */
        function _getPoolAddress(bytes32 poolId) internal pure returns (address) {
            // 12 byte logical shift left to remove the nonce and specialization setting. We don't need to mask,
            // since the logical shift already sets the upper bits to zero.
            return address(uint256(poolId) >> (12 * 8));
        }
        /**
         * @dev Returns the specialization setting of a Pool.
         *
         * Due to how Pool IDs are created, this is done with no storage accesses and costs little gas.
         */
        function _getPoolSpecialization(bytes32 poolId) internal pure returns (PoolSpecialization specialization) {
            // 10 byte logical shift left to remove the nonce, followed by a 2 byte mask to remove the address.
            uint256 value = uint256(poolId >> (10 * 8)) & (2**(2 * 8) - 1);
            // Casting a value into an enum results in a runtime check that reverts unless the value is within the enum's
            // range. Passing an invalid Pool ID to this function would then result in an obscure revert with no reason
            // string: we instead perform the check ourselves to help in error diagnosis.
            // There are three Pool specialization settings: general, minimal swap info and two tokens, which correspond to
            // values 0, 1 and 2.
            _require(value < 3, Errors.INVALID_POOL_ID);
            // Because we have checked that `value` is within the enum range, we can use assembly to skip the runtime check.
            // solhint-disable-next-line no-inline-assembly
            assembly {
                specialization := value
            }
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "../../lib/helpers/BalancerErrors.sol";
    import "../../lib/openzeppelin/EnumerableMap.sol";
    import "../../lib/openzeppelin/IERC20.sol";
    import "./BalanceAllocation.sol";
    abstract contract GeneralPoolsBalance {
        using BalanceAllocation for bytes32;
        using EnumerableMap for EnumerableMap.IERC20ToBytes32Map;
        // Data for Pools with the General specialization setting
        //
        // These Pools use the IGeneralPool interface, which means the Vault must query the balance for *all* of their
        // tokens in every swap. If we kept a mapping of token to balance plus a set (array) of tokens, it'd be very gas
        // intensive to read all token addresses just to then do a lookup on the balance mapping.
        //
        // Instead, we use our customized EnumerableMap, which lets us read the N balances in N+1 storage accesses (one for
        // each token in the Pool), access the index of any 'token in' a single read (required for the IGeneralPool call),
        // and update an entry's value given its index.
        // Map of token -> balance pairs for each Pool with this specialization. Many functions rely on storage pointers to
        // a Pool's EnumerableMap to save gas when computing storage slots.
        mapping(bytes32 => EnumerableMap.IERC20ToBytes32Map) internal _generalPoolsBalances;
        /**
         * @dev Registers a list of tokens in a General Pool.
         *
         * This function assumes `poolId` exists and corresponds to the General specialization setting.
         *
         * Requirements:
         *
         * - `tokens` must not be registered in the Pool
         * - `tokens` must not contain duplicates
         */
        function _registerGeneralPoolTokens(bytes32 poolId, IERC20[] memory tokens) internal {
            EnumerableMap.IERC20ToBytes32Map storage poolBalances = _generalPoolsBalances[poolId];
            for (uint256 i = 0; i < tokens.length; ++i) {
                // EnumerableMaps require an explicit initial value when creating a key-value pair: we use zero, the same
                // value that is found in uninitialized storage, which corresponds to an empty balance.
                bool added = poolBalances.set(tokens[i], 0);
                _require(added, Errors.TOKEN_ALREADY_REGISTERED);
            }
        }
        /**
         * @dev Deregisters a list of tokens in a General Pool.
         *
         * This function assumes `poolId` exists and corresponds to the General specialization setting.
         *
         * Requirements:
         *
         * - `tokens` must be registered in the Pool
         * - `tokens` must have zero balance in the Vault
         * - `tokens` must not contain duplicates
         */
        function _deregisterGeneralPoolTokens(bytes32 poolId, IERC20[] memory tokens) internal {
            EnumerableMap.IERC20ToBytes32Map storage poolBalances = _generalPoolsBalances[poolId];
            for (uint256 i = 0; i < tokens.length; ++i) {
                IERC20 token = tokens[i];
                bytes32 currentBalance = _getGeneralPoolBalance(poolBalances, token);
                _require(currentBalance.isZero(), Errors.NONZERO_TOKEN_BALANCE);
                // We don't need to check remove's return value, since _getGeneralPoolBalance already checks that the token
                // was registered.
                poolBalances.remove(token);
            }
        }
        /**
         * @dev Sets the balances of a General Pool's tokens to `balances`.
         *
         * WARNING: this assumes `balances` has the same length and order as the Pool's tokens.
         */
        function _setGeneralPoolBalances(bytes32 poolId, bytes32[] memory balances) internal {
            EnumerableMap.IERC20ToBytes32Map storage poolBalances = _generalPoolsBalances[poolId];
            for (uint256 i = 0; i < balances.length; ++i) {
                // Since we assume all balances are properly ordered, we can simply use `unchecked_setAt` to avoid one less
                // storage read per token.
                poolBalances.unchecked_setAt(i, balances[i]);
            }
        }
        /**
         * @dev Transforms `amount` of `token`'s balance in a General Pool from cash into managed.
         *
         * This function assumes `poolId` exists, corresponds to the General specialization setting, and that `token` is
         * registered for that Pool.
         */
        function _generalPoolCashToManaged(
            bytes32 poolId,
            IERC20 token,
            uint256 amount
        ) internal {
            _updateGeneralPoolBalance(poolId, token, BalanceAllocation.cashToManaged, amount);
        }
        /**
         * @dev Transforms `amount` of `token`'s balance in a General Pool from managed into cash.
         *
         * This function assumes `poolId` exists, corresponds to the General specialization setting, and that `token` is
         * registered for that Pool.
         */
        function _generalPoolManagedToCash(
            bytes32 poolId,
            IERC20 token,
            uint256 amount
        ) internal {
            _updateGeneralPoolBalance(poolId, token, BalanceAllocation.managedToCash, amount);
        }
        /**
         * @dev Sets `token`'s managed balance in a General Pool to `amount`.
         *
         * This function assumes `poolId` exists, corresponds to the General specialization setting, and that `token` is
         * registered for that Pool.
         *
         * Returns the managed balance delta as a result of this call.
         */
        function _setGeneralPoolManagedBalance(
            bytes32 poolId,
            IERC20 token,
            uint256 amount
        ) internal returns (int256) {
            return _updateGeneralPoolBalance(poolId, token, BalanceAllocation.setManaged, amount);
        }
        /**
         * @dev Sets `token`'s balance in a General Pool to the result of the `mutation` function when called with the
         * current balance and `amount`.
         *
         * This function assumes `poolId` exists, corresponds to the General specialization setting, and that `token` is
         * registered for that Pool.
         *
         * Returns the managed balance delta as a result of this call.
         */
        function _updateGeneralPoolBalance(
            bytes32 poolId,
            IERC20 token,
            function(bytes32, uint256) returns (bytes32) mutation,
            uint256 amount
        ) private returns (int256) {
            EnumerableMap.IERC20ToBytes32Map storage poolBalances = _generalPoolsBalances[poolId];
            bytes32 currentBalance = _getGeneralPoolBalance(poolBalances, token);
            bytes32 newBalance = mutation(currentBalance, amount);
            poolBalances.set(token, newBalance);
            return newBalance.managedDelta(currentBalance);
        }
        /**
         * @dev Returns an array with all the tokens and balances in a General Pool. The order may change when tokens are
         * registered or deregistered.
         *
         * This function assumes `poolId` exists and corresponds to the General specialization setting.
         */
        function _getGeneralPoolTokens(bytes32 poolId)
            internal
            view
            returns (IERC20[] memory tokens, bytes32[] memory balances)
        {
            EnumerableMap.IERC20ToBytes32Map storage poolBalances = _generalPoolsBalances[poolId];
            tokens = new IERC20[](poolBalances.length());
            balances = new bytes32[](tokens.length);
            for (uint256 i = 0; i < tokens.length; ++i) {
                // Because the iteration is bounded by `tokens.length`, which matches the EnumerableMap's length, we can use
                // `unchecked_at` as we know `i` is a valid token index, saving storage reads.
                (tokens[i], balances[i]) = poolBalances.unchecked_at(i);
            }
        }
        /**
         * @dev Returns the balance of a token in a General Pool.
         *
         * This function assumes `poolId` exists and corresponds to the General specialization setting.
         *
         * Requirements:
         *
         * - `token` must be registered in the Pool
         */
        function _getGeneralPoolBalance(bytes32 poolId, IERC20 token) internal view returns (bytes32) {
            EnumerableMap.IERC20ToBytes32Map storage poolBalances = _generalPoolsBalances[poolId];
            return _getGeneralPoolBalance(poolBalances, token);
        }
        /**
         * @dev Same as `_getGeneralPoolBalance` but using a Pool's storage pointer, which saves gas in repeated reads and
         * writes.
         */
        function _getGeneralPoolBalance(EnumerableMap.IERC20ToBytes32Map storage poolBalances, IERC20 token)
            private
            view
            returns (bytes32)
        {
            return poolBalances.get(token, Errors.TOKEN_NOT_REGISTERED);
        }
        /**
         * @dev Returns true if `token` is registered in a General Pool.
         *
         * This function assumes `poolId` exists and corresponds to the General specialization setting.
         */
        function _isGeneralPoolTokenRegistered(bytes32 poolId, IERC20 token) internal view returns (bool) {
            EnumerableMap.IERC20ToBytes32Map storage poolBalances = _generalPoolsBalances[poolId];
            return poolBalances.contains(token);
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "../../lib/helpers/BalancerErrors.sol";
    import "../../lib/openzeppelin/EnumerableSet.sol";
    import "../../lib/openzeppelin/IERC20.sol";
    import "./BalanceAllocation.sol";
    import "../PoolRegistry.sol";
    abstract contract MinimalSwapInfoPoolsBalance is PoolRegistry {
        using BalanceAllocation for bytes32;
        using EnumerableSet for EnumerableSet.AddressSet;
        // Data for Pools with the Minimal Swap Info specialization setting
        //
        // These Pools use the IMinimalSwapInfoPool interface, and so the Vault must read the balance of the two tokens
        // in the swap. The best solution is to use a mapping from token to balance, which lets us read or write any token's
        // balance in a single storage access.
        //
        // We also keep a set of registered tokens. Because tokens with non-zero balance are by definition registered, in
        // some balance getters we skip checking for token registration if a non-zero balance is found, saving gas by
        // performing a single read instead of two.
        mapping(bytes32 => mapping(IERC20 => bytes32)) internal _minimalSwapInfoPoolsBalances;
        mapping(bytes32 => EnumerableSet.AddressSet) internal _minimalSwapInfoPoolsTokens;
        /**
         * @dev Registers a list of tokens in a Minimal Swap Info Pool.
         *
         * This function assumes `poolId` exists and corresponds to the Minimal Swap Info specialization setting.
         *
         * Requirements:
         *
         * - `tokens` must not be registered in the Pool
         * - `tokens` must not contain duplicates
         */
        function _registerMinimalSwapInfoPoolTokens(bytes32 poolId, IERC20[] memory tokens) internal {
            EnumerableSet.AddressSet storage poolTokens = _minimalSwapInfoPoolsTokens[poolId];
            for (uint256 i = 0; i < tokens.length; ++i) {
                bool added = poolTokens.add(address(tokens[i]));
                _require(added, Errors.TOKEN_ALREADY_REGISTERED);
                // Note that we don't initialize the balance mapping: the default value of zero corresponds to an empty
                // balance.
            }
        }
        /**
         * @dev Deregisters a list of tokens in a Minimal Swap Info Pool.
         *
         * This function assumes `poolId` exists and corresponds to the Minimal Swap Info specialization setting.
         *
         * Requirements:
         *
         * - `tokens` must be registered in the Pool
         * - `tokens` must have zero balance in the Vault
         * - `tokens` must not contain duplicates
         */
        function _deregisterMinimalSwapInfoPoolTokens(bytes32 poolId, IERC20[] memory tokens) internal {
            EnumerableSet.AddressSet storage poolTokens = _minimalSwapInfoPoolsTokens[poolId];
            for (uint256 i = 0; i < tokens.length; ++i) {
                IERC20 token = tokens[i];
                _require(_minimalSwapInfoPoolsBalances[poolId][token].isZero(), Errors.NONZERO_TOKEN_BALANCE);
                // For consistency with other Pool specialization settings, we explicitly reset the balance (which may have
                // a non-zero last change block).
                delete _minimalSwapInfoPoolsBalances[poolId][token];
                bool removed = poolTokens.remove(address(token));
                _require(removed, Errors.TOKEN_NOT_REGISTERED);
            }
        }
        /**
         * @dev Sets the balances of a Minimal Swap Info Pool's tokens to `balances`.
         *
         * WARNING: this assumes `balances` has the same length and order as the Pool's tokens.
         */
        function _setMinimalSwapInfoPoolBalances(
            bytes32 poolId,
            IERC20[] memory tokens,
            bytes32[] memory balances
        ) internal {
            for (uint256 i = 0; i < tokens.length; ++i) {
                _minimalSwapInfoPoolsBalances[poolId][tokens[i]] = balances[i];
            }
        }
        /**
         * @dev Transforms `amount` of `token`'s balance in a Minimal Swap Info Pool from cash into managed.
         *
         * This function assumes `poolId` exists, corresponds to the Minimal Swap Info specialization setting, and that
         * `token` is registered for that Pool.
         */
        function _minimalSwapInfoPoolCashToManaged(
            bytes32 poolId,
            IERC20 token,
            uint256 amount
        ) internal {
            _updateMinimalSwapInfoPoolBalance(poolId, token, BalanceAllocation.cashToManaged, amount);
        }
        /**
         * @dev Transforms `amount` of `token`'s balance in a Minimal Swap Info Pool from managed into cash.
         *
         * This function assumes `poolId` exists, corresponds to the Minimal Swap Info specialization setting, and that
         * `token` is registered for that Pool.
         */
        function _minimalSwapInfoPoolManagedToCash(
            bytes32 poolId,
            IERC20 token,
            uint256 amount
        ) internal {
            _updateMinimalSwapInfoPoolBalance(poolId, token, BalanceAllocation.managedToCash, amount);
        }
        /**
         * @dev Sets `token`'s managed balance in a Minimal Swap Info Pool to `amount`.
         *
         * This function assumes `poolId` exists, corresponds to the Minimal Swap Info specialization setting, and that
         * `token` is registered for that Pool.
         *
         * Returns the managed balance delta as a result of this call.
         */
        function _setMinimalSwapInfoPoolManagedBalance(
            bytes32 poolId,
            IERC20 token,
            uint256 amount
        ) internal returns (int256) {
            return _updateMinimalSwapInfoPoolBalance(poolId, token, BalanceAllocation.setManaged, amount);
        }
        /**
         * @dev Sets `token`'s balance in a Minimal Swap Info Pool to the result of the `mutation` function when called with
         * the current balance and `amount`.
         *
         * This function assumes `poolId` exists, corresponds to the Minimal Swap Info specialization setting, and that
         * `token` is registered for that Pool.
         *
         * Returns the managed balance delta as a result of this call.
         */
        function _updateMinimalSwapInfoPoolBalance(
            bytes32 poolId,
            IERC20 token,
            function(bytes32, uint256) returns (bytes32) mutation,
            uint256 amount
        ) internal returns (int256) {
            bytes32 currentBalance = _getMinimalSwapInfoPoolBalance(poolId, token);
            bytes32 newBalance = mutation(currentBalance, amount);
            _minimalSwapInfoPoolsBalances[poolId][token] = newBalance;
            return newBalance.managedDelta(currentBalance);
        }
        /**
         * @dev Returns an array with all the tokens and balances in a Minimal Swap Info Pool. The order may change when
         * tokens are registered or deregistered.
         *
         * This function assumes `poolId` exists and corresponds to the Minimal Swap Info specialization setting.
         */
        function _getMinimalSwapInfoPoolTokens(bytes32 poolId)
            internal
            view
            returns (IERC20[] memory tokens, bytes32[] memory balances)
        {
            EnumerableSet.AddressSet storage poolTokens = _minimalSwapInfoPoolsTokens[poolId];
            tokens = new IERC20[](poolTokens.length());
            balances = new bytes32[](tokens.length);
            for (uint256 i = 0; i < tokens.length; ++i) {
                // Because the iteration is bounded by `tokens.length`, which matches the EnumerableSet's length, we can use
                // `unchecked_at` as we know `i` is a valid token index, saving storage reads.
                IERC20 token = IERC20(poolTokens.unchecked_at(i));
                tokens[i] = token;
                balances[i] = _minimalSwapInfoPoolsBalances[poolId][token];
            }
        }
        /**
         * @dev Returns the balance of a token in a Minimal Swap Info Pool.
         *
         * Requirements:
         *
         * - `poolId` must be a Minimal Swap Info Pool
         * - `token` must be registered in the Pool
         */
        function _getMinimalSwapInfoPoolBalance(bytes32 poolId, IERC20 token) internal view returns (bytes32) {
            bytes32 balance = _minimalSwapInfoPoolsBalances[poolId][token];
            // A non-zero balance guarantees that the token is registered. If zero, we manually check if the token is
            // registered in the Pool. Token registration implies that the Pool is registered as well, which lets us save
            // gas by not performing the check.
            bool tokenRegistered = balance.isNotZero() || _minimalSwapInfoPoolsTokens[poolId].contains(address(token));
            if (!tokenRegistered) {
                // The token might not be registered because the Pool itself is not registered. We check this to provide a
                // more accurate revert reason.
                _ensureRegisteredPool(poolId);
                _revert(Errors.TOKEN_NOT_REGISTERED);
            }
            return balance;
        }
        /**
         * @dev Returns true if `token` is registered in a Minimal Swap Info Pool.
         *
         * This function assumes `poolId` exists and corresponds to the Minimal Swap Info specialization setting.
         */
        function _isMinimalSwapInfoPoolTokenRegistered(bytes32 poolId, IERC20 token) internal view returns (bool) {
            EnumerableSet.AddressSet storage poolTokens = _minimalSwapInfoPoolsTokens[poolId];
            return poolTokens.contains(address(token));
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "../../lib/helpers/BalancerErrors.sol";
    import "../../lib/openzeppelin/IERC20.sol";
    import "./BalanceAllocation.sol";
    import "../PoolRegistry.sol";
    abstract contract TwoTokenPoolsBalance is PoolRegistry {
        using BalanceAllocation for bytes32;
        // Data for Pools with the Two Token specialization setting
        //
        // These are similar to the Minimal Swap Info Pool case (because the Pool only has two tokens, and therefore there
        // are only two balances to read), but there's a key difference in how data is stored. Keeping a set makes little
        // sense, as it will only ever hold two tokens, so we can just store those two directly.
        //
        // The gas savings associated with using these Pools come from how token balances are stored: cash amounts for token
        // A and token B are packed together, as are managed amounts. Because only cash changes in a swap, there's no need
        // to write to this second storage slot. A single last change block number for both tokens is stored with the packed
        // cash fields.
        struct TwoTokenPoolBalances {
            bytes32 sharedCash;
            bytes32 sharedManaged;
        }
        // We could just keep a mapping from Pool ID to TwoTokenSharedBalances, but there's an issue: we wouldn't know to
        // which tokens those balances correspond. This would mean having to also check which are registered with the Pool.
        //
        // What we do instead to save those storage reads is keep a nested mapping from the token pair hash to the balances
        // struct. The Pool only has two tokens, so only a single entry of this mapping is set (the one that corresponds to
        // that pair's hash).
        //
        // This has the trade-off of making Vault code that interacts with these Pools cumbersome: both balances must be
        // accessed at the same time by using both token addresses, and some logic is needed to determine how the pair hash
        // is computed. We do this by sorting the tokens, calling the token with the lowest numerical address value token A,
        // and the other one token B. In functions where the token arguments could be either A or B, we use X and Y instead.
        //
        // If users query a token pair containing an unregistered token, the Pool will generate a hash for a mapping entry
        // that was not set, and return zero balances. Non-zero balances are only possible if both tokens in the pair
        // are registered with the Pool, which means we don't have to check the TwoTokenPoolTokens struct, and can save
        // storage reads.
        struct TwoTokenPoolTokens {
            IERC20 tokenA;
            IERC20 tokenB;
            mapping(bytes32 => TwoTokenPoolBalances) balances;
        }
        mapping(bytes32 => TwoTokenPoolTokens) private _twoTokenPoolTokens;
        /**
         * @dev Registers tokens in a Two Token Pool.
         *
         * This function assumes `poolId` exists and corresponds to the Two Token specialization setting.
         *
         * Requirements:
         *
         * - `tokenX` and `tokenY` must not be the same
         * - The tokens must be ordered: tokenX < tokenY
         */
        function _registerTwoTokenPoolTokens(
            bytes32 poolId,
            IERC20 tokenX,
            IERC20 tokenY
        ) internal {
            // Not technically true since we didn't register yet, but this is consistent with the error messages of other
            // specialization settings.
            _require(tokenX != tokenY, Errors.TOKEN_ALREADY_REGISTERED);
            _require(tokenX < tokenY, Errors.UNSORTED_TOKENS);
            // A Two Token Pool with no registered tokens is identified by having zero addresses for tokens A and B.
            TwoTokenPoolTokens storage poolTokens = _twoTokenPoolTokens[poolId];
            _require(poolTokens.tokenA == IERC20(0) && poolTokens.tokenB == IERC20(0), Errors.TOKENS_ALREADY_SET);
            // Since tokenX < tokenY, tokenX is A and tokenY is B
            poolTokens.tokenA = tokenX;
            poolTokens.tokenB = tokenY;
            // Note that we don't initialize the balance mapping: the default value of zero corresponds to an empty
            // balance.
        }
        /**
         * @dev Deregisters tokens in a Two Token Pool.
         *
         * This function assumes `poolId` exists and corresponds to the Two Token specialization setting.
         *
         * Requirements:
         *
         * - `tokenX` and `tokenY` must be registered in the Pool
         * - both tokens must have zero balance in the Vault
         */
        function _deregisterTwoTokenPoolTokens(
            bytes32 poolId,
            IERC20 tokenX,
            IERC20 tokenY
        ) internal {
            (
                bytes32 balanceA,
                bytes32 balanceB,
                TwoTokenPoolBalances storage poolBalances
            ) = _getTwoTokenPoolSharedBalances(poolId, tokenX, tokenY);
            _require(balanceA.isZero() && balanceB.isZero(), Errors.NONZERO_TOKEN_BALANCE);
            delete _twoTokenPoolTokens[poolId];
            // For consistency with other Pool specialization settings, we explicitly reset the packed cash field (which may
            // have a non-zero last change block).
            delete poolBalances.sharedCash;
        }
        /**
         * @dev Sets the cash balances of a Two Token Pool's tokens.
         *
         * WARNING: this assumes `tokenA` and `tokenB` are the Pool's two registered tokens, and are in the correct order.
         */
        function _setTwoTokenPoolCashBalances(
            bytes32 poolId,
            IERC20 tokenA,
            bytes32 balanceA,
            IERC20 tokenB,
            bytes32 balanceB
        ) internal {
            bytes32 pairHash = _getTwoTokenPairHash(tokenA, tokenB);
            TwoTokenPoolBalances storage poolBalances = _twoTokenPoolTokens[poolId].balances[pairHash];
            poolBalances.sharedCash = BalanceAllocation.toSharedCash(balanceA, balanceB);
        }
        /**
         * @dev Transforms `amount` of `token`'s balance in a Two Token Pool from cash into managed.
         *
         * This function assumes `poolId` exists, corresponds to the Two Token specialization setting, and that `token` is
         * registered for that Pool.
         */
        function _twoTokenPoolCashToManaged(
            bytes32 poolId,
            IERC20 token,
            uint256 amount
        ) internal {
            _updateTwoTokenPoolSharedBalance(poolId, token, BalanceAllocation.cashToManaged, amount);
        }
        /**
         * @dev Transforms `amount` of `token`'s balance in a Two Token Pool from managed into cash.
         *
         * This function assumes `poolId` exists, corresponds to the Two Token specialization setting, and that `token` is
         * registered for that Pool.
         */
        function _twoTokenPoolManagedToCash(
            bytes32 poolId,
            IERC20 token,
            uint256 amount
        ) internal {
            _updateTwoTokenPoolSharedBalance(poolId, token, BalanceAllocation.managedToCash, amount);
        }
        /**
         * @dev Sets `token`'s managed balance in a Two Token Pool to `amount`.
         *
         * This function assumes `poolId` exists, corresponds to the Two Token specialization setting, and that `token` is
         * registered for that Pool.
         *
         * Returns the managed balance delta as a result of this call.
         */
        function _setTwoTokenPoolManagedBalance(
            bytes32 poolId,
            IERC20 token,
            uint256 amount
        ) internal returns (int256) {
            return _updateTwoTokenPoolSharedBalance(poolId, token, BalanceAllocation.setManaged, amount);
        }
        /**
         * @dev Sets `token`'s balance in a Two Token Pool to the result of the `mutation` function when called with
         * the current balance and `amount`.
         *
         * This function assumes `poolId` exists, corresponds to the Two Token specialization setting, and that `token` is
         * registered for that Pool.
         *
         * Returns the managed balance delta as a result of this call.
         */
        function _updateTwoTokenPoolSharedBalance(
            bytes32 poolId,
            IERC20 token,
            function(bytes32, uint256) returns (bytes32) mutation,
            uint256 amount
        ) private returns (int256) {
            (
                TwoTokenPoolBalances storage balances,
                IERC20 tokenA,
                bytes32 balanceA,
                ,
                bytes32 balanceB
            ) = _getTwoTokenPoolBalances(poolId);
            int256 delta;
            if (token == tokenA) {
                bytes32 newBalance = mutation(balanceA, amount);
                delta = newBalance.managedDelta(balanceA);
                balanceA = newBalance;
            } else {
                // token == tokenB
                bytes32 newBalance = mutation(balanceB, amount);
                delta = newBalance.managedDelta(balanceB);
                balanceB = newBalance;
            }
            balances.sharedCash = BalanceAllocation.toSharedCash(balanceA, balanceB);
            balances.sharedManaged = BalanceAllocation.toSharedManaged(balanceA, balanceB);
            return delta;
        }
        /*
         * @dev Returns an array with all the tokens and balances in a Two Token Pool. The order may change when
         * tokens are registered or deregistered.
         *
         * This function assumes `poolId` exists and corresponds to the Two Token specialization setting.
         */
        function _getTwoTokenPoolTokens(bytes32 poolId)
            internal
            view
            returns (IERC20[] memory tokens, bytes32[] memory balances)
        {
            (, IERC20 tokenA, bytes32 balanceA, IERC20 tokenB, bytes32 balanceB) = _getTwoTokenPoolBalances(poolId);
            // Both tokens will either be zero (if unregistered) or non-zero (if registered), but we keep the full check for
            // clarity.
            if (tokenA == IERC20(0) || tokenB == IERC20(0)) {
                return (new IERC20[](0), new bytes32[](0));
            }
            // Note that functions relying on this getter expect tokens to be properly ordered, so we use the (A, B)
            // ordering.
            tokens = new IERC20[](2);
            tokens[0] = tokenA;
            tokens[1] = tokenB;
            balances = new bytes32[](2);
            balances[0] = balanceA;
            balances[1] = balanceB;
        }
        /**
         * @dev Same as `_getTwoTokenPoolTokens`, except it returns the two tokens and balances directly instead of using
         * an array, as well as a storage pointer to the `TwoTokenPoolBalances` struct, which can be used to update it
         * without having to recompute the pair hash and storage slot.
         */
        function _getTwoTokenPoolBalances(bytes32 poolId)
            private
            view
            returns (
                TwoTokenPoolBalances storage poolBalances,
                IERC20 tokenA,
                bytes32 balanceA,
                IERC20 tokenB,
                bytes32 balanceB
            )
        {
            TwoTokenPoolTokens storage poolTokens = _twoTokenPoolTokens[poolId];
            tokenA = poolTokens.tokenA;
            tokenB = poolTokens.tokenB;
            bytes32 pairHash = _getTwoTokenPairHash(tokenA, tokenB);
            poolBalances = poolTokens.balances[pairHash];
            bytes32 sharedCash = poolBalances.sharedCash;
            bytes32 sharedManaged = poolBalances.sharedManaged;
            balanceA = BalanceAllocation.fromSharedToBalanceA(sharedCash, sharedManaged);
            balanceB = BalanceAllocation.fromSharedToBalanceB(sharedCash, sharedManaged);
        }
        /**
         * @dev Returns the balance of a token in a Two Token Pool.
         *
         * This function assumes `poolId` exists and corresponds to the General specialization setting.
         *
         * This function is convenient but not particularly gas efficient, and should be avoided during gas-sensitive
         * operations, such as swaps. For those, _getTwoTokenPoolSharedBalances provides a more flexible interface.
         *
         * Requirements:
         *
         * - `token` must be registered in the Pool
         */
        function _getTwoTokenPoolBalance(bytes32 poolId, IERC20 token) internal view returns (bytes32) {
            // We can't just read the balance of token, because we need to know the full pair in order to compute the pair
            // hash and access the balance mapping. We therefore rely on `_getTwoTokenPoolBalances`.
            (, IERC20 tokenA, bytes32 balanceA, IERC20 tokenB, bytes32 balanceB) = _getTwoTokenPoolBalances(poolId);
            if (token == tokenA) {
                return balanceA;
            } else if (token == tokenB) {
                return balanceB;
            } else {
                _revert(Errors.TOKEN_NOT_REGISTERED);
            }
        }
        /**
         * @dev Returns the balance of the two tokens in a Two Token Pool.
         *
         * The returned balances are those of token A and token B, where token A is the lowest of token X and token Y, and
         * token B the other.
         *
         * This function also returns a storage pointer to the TwoTokenPoolBalances struct associated with the token pair,
         * which can be used to update it without having to recompute the pair hash and storage slot.
         *
         * Requirements:
         *
         * - `poolId` must be a Minimal Swap Info Pool
         * - `tokenX` and `tokenY` must be registered in the Pool
         */
        function _getTwoTokenPoolSharedBalances(
            bytes32 poolId,
            IERC20 tokenX,
            IERC20 tokenY
        )
            internal
            view
            returns (
                bytes32 balanceA,
                bytes32 balanceB,
                TwoTokenPoolBalances storage poolBalances
            )
        {
            (IERC20 tokenA, IERC20 tokenB) = _sortTwoTokens(tokenX, tokenY);
            bytes32 pairHash = _getTwoTokenPairHash(tokenA, tokenB);
            poolBalances = _twoTokenPoolTokens[poolId].balances[pairHash];
            // Because we're reading balances using the pair hash, if either token X or token Y is not registered then
            // *both* balance entries will be zero.
            bytes32 sharedCash = poolBalances.sharedCash;
            bytes32 sharedManaged = poolBalances.sharedManaged;
            // A non-zero balance guarantees that both tokens are registered. If zero, we manually check whether each
            // token is registered in the Pool. Token registration implies that the Pool is registered as well, which
            // lets us save gas by not performing the check.
            bool tokensRegistered = sharedCash.isNotZero() ||
                sharedManaged.isNotZero() ||
                (_isTwoTokenPoolTokenRegistered(poolId, tokenA) && _isTwoTokenPoolTokenRegistered(poolId, tokenB));
            if (!tokensRegistered) {
                // The tokens might not be registered because the Pool itself is not registered. We check this to provide a
                // more accurate revert reason.
                _ensureRegisteredPool(poolId);
                _revert(Errors.TOKEN_NOT_REGISTERED);
            }
            balanceA = BalanceAllocation.fromSharedToBalanceA(sharedCash, sharedManaged);
            balanceB = BalanceAllocation.fromSharedToBalanceB(sharedCash, sharedManaged);
        }
        /**
         * @dev Returns true if `token` is registered in a Two Token Pool.
         *
         * This function assumes `poolId` exists and corresponds to the Two Token specialization setting.
         */
        function _isTwoTokenPoolTokenRegistered(bytes32 poolId, IERC20 token) internal view returns (bool) {
            TwoTokenPoolTokens storage poolTokens = _twoTokenPoolTokens[poolId];
            // The zero address can never be a registered token.
            return (token == poolTokens.tokenA || token == poolTokens.tokenB) && token != IERC20(0);
        }
        /**
         * @dev Returns the hash associated with a given token pair.
         */
        function _getTwoTokenPairHash(IERC20 tokenA, IERC20 tokenB) private pure returns (bytes32) {
            return keccak256(abi.encodePacked(tokenA, tokenB));
        }
        /**
         * @dev Sorts two tokens in ascending order, returning them as a (tokenA, tokenB) tuple.
         */
        function _sortTwoTokens(IERC20 tokenX, IERC20 tokenY) private pure returns (IERC20, IERC20) {
            return tokenX < tokenY ? (tokenX, tokenY) : (tokenY, tokenX);
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "../lib/math/Math.sol";
    import "../lib/helpers/BalancerErrors.sol";
    import "../lib/openzeppelin/IERC20.sol";
    import "../lib/helpers/AssetHelpers.sol";
    import "../lib/openzeppelin/SafeERC20.sol";
    import "../lib/openzeppelin/Address.sol";
    import "./interfaces/IWETH.sol";
    import "./interfaces/IAsset.sol";
    import "./interfaces/IVault.sol";
    abstract contract AssetTransfersHandler is AssetHelpers {
        using SafeERC20 for IERC20;
        using Address for address payable;
        /**
         * @dev Receives `amount` of `asset` from `sender`. If `fromInternalBalance` is true, it first withdraws as much
         * as possible from Internal Balance, then transfers any remaining amount.
         *
         * If `asset` is ETH, `fromInternalBalance` must be false (as ETH cannot be held as internal balance), and the funds
         * will be wrapped into WETH.
         *
         * WARNING: this function does not check that the contract caller has actually supplied any ETH - it is up to the
         * caller of this function to check that this is true to prevent the Vault from using its own ETH (though the Vault
         * typically doesn't hold any).
         */
        function _receiveAsset(
            IAsset asset,
            uint256 amount,
            address sender,
            bool fromInternalBalance
        ) internal {
            if (amount == 0) {
                return;
            }
            if (_isETH(asset)) {
                _require(!fromInternalBalance, Errors.INVALID_ETH_INTERNAL_BALANCE);
                // The ETH amount to receive is deposited into the WETH contract, which will in turn mint WETH for
                // the Vault at a 1:1 ratio.
                // A check for this condition is also introduced by the compiler, but this one provides a revert reason.
                // Note we're checking for the Vault's total balance, *not* ETH sent in this transaction.
                _require(address(this).balance >= amount, Errors.INSUFFICIENT_ETH);
                _WETH().deposit{ value: amount }();
            } else {
                IERC20 token = _asIERC20(asset);
                if (fromInternalBalance) {
                    // We take as many tokens from Internal Balance as possible: any remaining amounts will be transferred.
                    uint256 deductedBalance = _decreaseInternalBalance(sender, token, amount, true);
                    // Because `deductedBalance` will be always the lesser of the current internal balance
                    // and the amount to decrease, it is safe to perform unchecked arithmetic.
                    amount -= deductedBalance;
                }
                if (amount > 0) {
                    token.safeTransferFrom(sender, address(this), amount);
                }
            }
        }
        /**
         * @dev Sends `amount` of `asset` to `recipient`. If `toInternalBalance` is true, the asset is deposited as Internal
         * Balance instead of being transferred.
         *
         * If `asset` is ETH, `toInternalBalance` must be false (as ETH cannot be held as internal balance), and the funds
         * are instead sent directly after unwrapping WETH.
         */
        function _sendAsset(
            IAsset asset,
            uint256 amount,
            address payable recipient,
            bool toInternalBalance
        ) internal {
            if (amount == 0) {
                return;
            }
            if (_isETH(asset)) {
                // Sending ETH is not as involved as receiving it: the only special behavior is it cannot be
                // deposited to Internal Balance.
                _require(!toInternalBalance, Errors.INVALID_ETH_INTERNAL_BALANCE);
                // First, the Vault withdraws deposited ETH from the WETH contract, by burning the same amount of WETH
                // from the Vault. This receipt will be handled by the Vault's `receive`.
                _WETH().withdraw(amount);
                // Then, the withdrawn ETH is sent to the recipient.
                recipient.sendValue(amount);
            } else {
                IERC20 token = _asIERC20(asset);
                if (toInternalBalance) {
                    _increaseInternalBalance(recipient, token, amount);
                } else {
                    token.safeTransfer(recipient, amount);
                }
            }
        }
        /**
         * @dev Returns excess ETH back to the contract caller, assuming `amountUsed` has been spent. Reverts
         * if the caller sent less ETH than `amountUsed`.
         *
         * Because the caller might not know exactly how much ETH a Vault action will require, they may send extra.
         * Note that this excess value is returned *to the contract caller* (msg.sender). If caller and e.g. swap sender are
         * not the same (because the caller is a relayer for the sender), then it is up to the caller to manage this
         * returned ETH.
         */
        function _handleRemainingEth(uint256 amountUsed) internal {
            _require(msg.value >= amountUsed, Errors.INSUFFICIENT_ETH);
            uint256 excess = msg.value - amountUsed;
            if (excess > 0) {
                msg.sender.sendValue(excess);
            }
        }
        /**
         * @dev Enables the Vault to receive ETH. This is required for it to be able to unwrap WETH, which sends ETH to the
         * caller.
         *
         * Any ETH sent to the Vault outside of the WETH unwrapping mechanism would be forever locked inside the Vault, so
         * we prevent that from happening. Other mechanisms used to send ETH to the Vault (such as being the recipient of an
         * ETH swap, Pool exit or withdrawal, contract self-destruction, or receiving the block mining reward) will result
         * in locked funds, but are not otherwise a security or soundness issue. This check only exists as an attempt to
         * prevent user error.
         */
        receive() external payable {
            _require(msg.sender == address(_WETH()), Errors.ETH_TRANSFER);
        }
        // This contract uses virtual internal functions instead of inheriting from the modules that implement them (in
        // this case UserBalance) in order to decouple it from the rest of the system and enable standalone testing by
        // implementing these with mocks.
        function _increaseInternalBalance(
            address account,
            IERC20 token,
            uint256 amount
        ) internal virtual;
        function _decreaseInternalBalance(
            address account,
            IERC20 token,
            uint256 amount,
            bool capped
        ) internal virtual returns (uint256);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "../openzeppelin/IERC20.sol";
    import "../../vault/interfaces/IAsset.sol";
    import "../../vault/interfaces/IWETH.sol";
    abstract contract AssetHelpers {
        // solhint-disable-next-line var-name-mixedcase
        IWETH private immutable _weth;
        // Sentinel value used to indicate WETH with wrapping/unwrapping semantics. The zero address is a good choice for
        // multiple reasons: it is cheap to pass as a calldata argument, it is a known invalid token and non-contract, and
        // it is an address Pools cannot register as a token.
        address private constant _ETH = address(0);
        constructor(IWETH weth) {
            _weth = weth;
        }
        // solhint-disable-next-line func-name-mixedcase
        function _WETH() internal view returns (IWETH) {
            return _weth;
        }
        /**
         * @dev Returns true if `asset` is the sentinel value that represents ETH.
         */
        function _isETH(IAsset asset) internal pure returns (bool) {
            return address(asset) == _ETH;
        }
        /**
         * @dev Translates `asset` into an equivalent IERC20 token address. If `asset` represents ETH, it will be translated
         * to the WETH contract.
         */
        function _translateToIERC20(IAsset asset) internal view returns (IERC20) {
            return _isETH(asset) ? _WETH() : _asIERC20(asset);
        }
        /**
         * @dev Same as `_translateToIERC20(IAsset)`, but for an entire array.
         */
        function _translateToIERC20(IAsset[] memory assets) internal view returns (IERC20[] memory) {
            IERC20[] memory tokens = new IERC20[](assets.length);
            for (uint256 i = 0; i < assets.length; ++i) {
                tokens[i] = _translateToIERC20(assets[i]);
            }
            return tokens;
        }
        /**
         * @dev Interprets `asset` as an IERC20 token. This function should only be called on `asset` if `_isETH` previously
         * returned false for it, that is, if `asset` is guaranteed not to be the ETH sentinel value.
         */
        function _asIERC20(IAsset asset) internal pure returns (IERC20) {
            return IERC20(address(asset));
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.7.0;
    import "../helpers/BalancerErrors.sol";
    /**
     * @dev Collection of functions related to the address type
     */
    library Address {
        /**
         * @dev Returns true if `account` is a contract.
         *
         * [IMPORTANT]
         * ====
         * It is unsafe to assume that an address for which this function returns
         * false is an externally-owned account (EOA) and not a contract.
         *
         * Among others, `isContract` will return false for the following
         * types of addresses:
         *
         *  - an externally-owned account
         *  - a contract in construction
         *  - an address where a contract will be created
         *  - an address where a contract lived, but was destroyed
         * ====
         */
        function isContract(address account) internal view returns (bool) {
            // This method relies on extcodesize, which returns 0 for contracts in
            // construction, since the code is only stored at the end of the
            // constructor execution.
            uint256 size;
            // solhint-disable-next-line no-inline-assembly
            assembly {
                size := extcodesize(account)
            }
            return size > 0;
        }
        /**
         * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
         * `recipient`, forwarding all available gas and reverting on errors.
         *
         * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
         * of certain opcodes, possibly making contracts go over the 2300 gas limit
         * imposed by `transfer`, making them unable to receive funds via
         * `transfer`. {sendValue} removes this limitation.
         *
         * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
         *
         * IMPORTANT: because control is transferred to `recipient`, care must be
         * taken to not create reentrancy vulnerabilities. Consider using
         * {ReentrancyGuard} or the
         * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
         */
        function sendValue(address payable recipient, uint256 amount) internal {
            _require(address(this).balance >= amount, Errors.ADDRESS_INSUFFICIENT_BALANCE);
            // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
            (bool success, ) = recipient.call{ value: amount }("");
            _require(success, Errors.ADDRESS_CANNOT_SEND_VALUE);
        }
    }
    

    File 2 of 4: TempleERC20Token
    pragma solidity ^0.8.4;
    // SPDX-License-Identifier: GPL-3.0-or-later
    import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
    import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
    import "@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol";
    import "@openzeppelin/contracts/security/Pausable.sol";
    import "@openzeppelin/contracts/access/Ownable.sol";
    import "@openzeppelin/contracts/access/AccessControl.sol";
    contract TempleERC20Token is ERC20, ERC20Burnable, Ownable, AccessControl {
        bytes32 public constant CAN_MINT = keccak256("CAN_MINT");
        constructor() ERC20("Temple", "TEMPLE") {
            _setupRole(DEFAULT_ADMIN_ROLE, owner());
        }
        function mint(address to, uint256 amount) external {
          require(hasRole(CAN_MINT, msg.sender), "Caller cannot mint");
          _mint(to, amount);
        }
        function addMinter(address account) external onlyOwner {
            grantRole(CAN_MINT, account);
        }
        function removeMinter(address account) external onlyOwner {
            revokeRole(CAN_MINT, account);
        }
    }// SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    import "./IERC20.sol";
    import "./extensions/IERC20Metadata.sol";
    import "../../utils/Context.sol";
    /**
     * @dev Implementation of the {IERC20} interface.
     *
     * This implementation is agnostic to the way tokens are created. This means
     * that a supply mechanism has to be added in a derived contract using {_mint}.
     * For a generic mechanism see {ERC20PresetMinterPauser}.
     *
     * TIP: For a detailed writeup see our guide
     * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
     * to implement supply mechanisms].
     *
     * We have followed general OpenZeppelin Contracts guidelines: functions revert
     * instead returning `false` on failure. This behavior is nonetheless
     * conventional and does not conflict with the expectations of ERC20
     * applications.
     *
     * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
     * This allows applications to reconstruct the allowance for all accounts just
     * by listening to said events. Other implementations of the EIP may not emit
     * these events, as it isn't required by the specification.
     *
     * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
     * functions have been added to mitigate the well-known issues around setting
     * allowances. See {IERC20-approve}.
     */
    contract ERC20 is Context, IERC20, IERC20Metadata {
        mapping(address => uint256) private _balances;
        mapping(address => mapping(address => uint256)) private _allowances;
        uint256 private _totalSupply;
        string private _name;
        string private _symbol;
        /**
         * @dev Sets the values for {name} and {symbol}.
         *
         * The default value of {decimals} is 18. To select a different value for
         * {decimals} you should overload it.
         *
         * All two of these values are immutable: they can only be set once during
         * construction.
         */
        constructor(string memory name_, string memory symbol_) {
            _name = name_;
            _symbol = symbol_;
        }
        /**
         * @dev Returns the name of the token.
         */
        function name() public view virtual override returns (string memory) {
            return _name;
        }
        /**
         * @dev Returns the symbol of the token, usually a shorter version of the
         * name.
         */
        function symbol() public view virtual override returns (string memory) {
            return _symbol;
        }
        /**
         * @dev Returns the number of decimals used to get its user representation.
         * For example, if `decimals` equals `2`, a balance of `505` tokens should
         * be displayed to a user as `5.05` (`505 / 10 ** 2`).
         *
         * Tokens usually opt for a value of 18, imitating the relationship between
         * Ether and Wei. This is the value {ERC20} uses, unless this function is
         * overridden;
         *
         * NOTE: This information is only used for _display_ purposes: it in
         * no way affects any of the arithmetic of the contract, including
         * {IERC20-balanceOf} and {IERC20-transfer}.
         */
        function decimals() public view virtual override returns (uint8) {
            return 18;
        }
        /**
         * @dev See {IERC20-totalSupply}.
         */
        function totalSupply() public view virtual override returns (uint256) {
            return _totalSupply;
        }
        /**
         * @dev See {IERC20-balanceOf}.
         */
        function balanceOf(address account) public view virtual override returns (uint256) {
            return _balances[account];
        }
        /**
         * @dev See {IERC20-transfer}.
         *
         * Requirements:
         *
         * - `recipient` cannot be the zero address.
         * - the caller must have a balance of at least `amount`.
         */
        function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
            _transfer(_msgSender(), recipient, amount);
            return true;
        }
        /**
         * @dev See {IERC20-allowance}.
         */
        function allowance(address owner, address spender) public view virtual override returns (uint256) {
            return _allowances[owner][spender];
        }
        /**
         * @dev See {IERC20-approve}.
         *
         * Requirements:
         *
         * - `spender` cannot be the zero address.
         */
        function approve(address spender, uint256 amount) public virtual override returns (bool) {
            _approve(_msgSender(), spender, amount);
            return true;
        }
        /**
         * @dev See {IERC20-transferFrom}.
         *
         * Emits an {Approval} event indicating the updated allowance. This is not
         * required by the EIP. See the note at the beginning of {ERC20}.
         *
         * Requirements:
         *
         * - `sender` and `recipient` cannot be the zero address.
         * - `sender` must have a balance of at least `amount`.
         * - the caller must have allowance for ``sender``'s tokens of at least
         * `amount`.
         */
        function transferFrom(
            address sender,
            address recipient,
            uint256 amount
        ) public virtual override returns (bool) {
            _transfer(sender, recipient, amount);
            uint256 currentAllowance = _allowances[sender][_msgSender()];
            require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
            unchecked {
                _approve(sender, _msgSender(), currentAllowance - amount);
            }
            return true;
        }
        /**
         * @dev Atomically increases the allowance granted to `spender` by the caller.
         *
         * This is an alternative to {approve} that can be used as a mitigation for
         * problems described in {IERC20-approve}.
         *
         * Emits an {Approval} event indicating the updated allowance.
         *
         * Requirements:
         *
         * - `spender` cannot be the zero address.
         */
        function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
            _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
            return true;
        }
        /**
         * @dev Atomically decreases the allowance granted to `spender` by the caller.
         *
         * This is an alternative to {approve} that can be used as a mitigation for
         * problems described in {IERC20-approve}.
         *
         * Emits an {Approval} event indicating the updated allowance.
         *
         * Requirements:
         *
         * - `spender` cannot be the zero address.
         * - `spender` must have allowance for the caller of at least
         * `subtractedValue`.
         */
        function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
            uint256 currentAllowance = _allowances[_msgSender()][spender];
            require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
            unchecked {
                _approve(_msgSender(), spender, currentAllowance - subtractedValue);
            }
            return true;
        }
        /**
         * @dev Moves `amount` of tokens from `sender` to `recipient`.
         *
         * This internal function is equivalent to {transfer}, and can be used to
         * e.g. implement automatic token fees, slashing mechanisms, etc.
         *
         * Emits a {Transfer} event.
         *
         * Requirements:
         *
         * - `sender` cannot be the zero address.
         * - `recipient` cannot be the zero address.
         * - `sender` must have a balance of at least `amount`.
         */
        function _transfer(
            address sender,
            address recipient,
            uint256 amount
        ) internal virtual {
            require(sender != address(0), "ERC20: transfer from the zero address");
            require(recipient != address(0), "ERC20: transfer to the zero address");
            _beforeTokenTransfer(sender, recipient, amount);
            uint256 senderBalance = _balances[sender];
            require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
            unchecked {
                _balances[sender] = senderBalance - amount;
            }
            _balances[recipient] += amount;
            emit Transfer(sender, recipient, amount);
            _afterTokenTransfer(sender, recipient, amount);
        }
        /** @dev Creates `amount` tokens and assigns them to `account`, increasing
         * the total supply.
         *
         * Emits a {Transfer} event with `from` set to the zero address.
         *
         * Requirements:
         *
         * - `account` cannot be the zero address.
         */
        function _mint(address account, uint256 amount) internal virtual {
            require(account != address(0), "ERC20: mint to the zero address");
            _beforeTokenTransfer(address(0), account, amount);
            _totalSupply += amount;
            _balances[account] += amount;
            emit Transfer(address(0), account, amount);
            _afterTokenTransfer(address(0), account, amount);
        }
        /**
         * @dev Destroys `amount` tokens from `account`, reducing the
         * total supply.
         *
         * Emits a {Transfer} event with `to` set to the zero address.
         *
         * Requirements:
         *
         * - `account` cannot be the zero address.
         * - `account` must have at least `amount` tokens.
         */
        function _burn(address account, uint256 amount) internal virtual {
            require(account != address(0), "ERC20: burn from the zero address");
            _beforeTokenTransfer(account, address(0), amount);
            uint256 accountBalance = _balances[account];
            require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
            unchecked {
                _balances[account] = accountBalance - amount;
            }
            _totalSupply -= amount;
            emit Transfer(account, address(0), amount);
            _afterTokenTransfer(account, address(0), amount);
        }
        /**
         * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
         *
         * This internal function is equivalent to `approve`, and can be used to
         * e.g. set automatic allowances for certain subsystems, etc.
         *
         * Emits an {Approval} event.
         *
         * Requirements:
         *
         * - `owner` cannot be the zero address.
         * - `spender` cannot be the zero address.
         */
        function _approve(
            address owner,
            address spender,
            uint256 amount
        ) internal virtual {
            require(owner != address(0), "ERC20: approve from the zero address");
            require(spender != address(0), "ERC20: approve to the zero address");
            _allowances[owner][spender] = amount;
            emit Approval(owner, spender, amount);
        }
        /**
         * @dev Hook that is called before any transfer of tokens. This includes
         * minting and burning.
         *
         * Calling conditions:
         *
         * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
         * will be transferred to `to`.
         * - when `from` is zero, `amount` tokens will be minted for `to`.
         * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
         * - `from` and `to` are never both zero.
         *
         * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
         */
        function _beforeTokenTransfer(
            address from,
            address to,
            uint256 amount
        ) internal virtual {}
        /**
         * @dev Hook that is called after any transfer of tokens. This includes
         * minting and burning.
         *
         * Calling conditions:
         *
         * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
         * has been transferred to `to`.
         * - when `from` is zero, `amount` tokens have been minted for `to`.
         * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
         * - `from` and `to` are never both zero.
         *
         * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
         */
        function _afterTokenTransfer(
            address from,
            address to,
            uint256 amount
        ) internal virtual {}
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    /**
     * @dev Interface of the ERC20 standard as defined in the EIP.
     */
    interface IERC20 {
        /**
         * @dev Returns the amount of tokens in existence.
         */
        function totalSupply() external view returns (uint256);
        /**
         * @dev Returns the amount of tokens owned by `account`.
         */
        function balanceOf(address account) external view returns (uint256);
        /**
         * @dev Moves `amount` tokens from the caller's account to `recipient`.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * Emits a {Transfer} event.
         */
        function transfer(address recipient, uint256 amount) external returns (bool);
        /**
         * @dev Returns the remaining number of tokens that `spender` will be
         * allowed to spend on behalf of `owner` through {transferFrom}. This is
         * zero by default.
         *
         * This value changes when {approve} or {transferFrom} are called.
         */
        function allowance(address owner, address spender) external view returns (uint256);
        /**
         * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * IMPORTANT: Beware that changing an allowance with this method brings the risk
         * that someone may use both the old and the new allowance by unfortunate
         * transaction ordering. One possible solution to mitigate this race
         * condition is to first reduce the spender's allowance to 0 and set the
         * desired value afterwards:
         * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
         *
         * Emits an {Approval} event.
         */
        function approve(address spender, uint256 amount) external returns (bool);
        /**
         * @dev Moves `amount` tokens from `sender` to `recipient` using the
         * allowance mechanism. `amount` is then deducted from the caller's
         * allowance.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * Emits a {Transfer} event.
         */
        function transferFrom(
            address sender,
            address recipient,
            uint256 amount
        ) external returns (bool);
        /**
         * @dev Emitted when `value` tokens are moved from one account (`from`) to
         * another (`to`).
         *
         * Note that `value` may be zero.
         */
        event Transfer(address indexed from, address indexed to, uint256 value);
        /**
         * @dev Emitted when the allowance of a `spender` for an `owner` is set by
         * a call to {approve}. `value` is the new allowance.
         */
        event Approval(address indexed owner, address indexed spender, uint256 value);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    import "../ERC20.sol";
    import "../../../utils/Context.sol";
    /**
     * @dev Extension of {ERC20} that allows token holders to destroy both their own
     * tokens and those that they have an allowance for, in a way that can be
     * recognized off-chain (via event analysis).
     */
    abstract contract ERC20Burnable is Context, ERC20 {
        /**
         * @dev Destroys `amount` tokens from the caller.
         *
         * See {ERC20-_burn}.
         */
        function burn(uint256 amount) public virtual {
            _burn(_msgSender(), amount);
        }
        /**
         * @dev Destroys `amount` tokens from `account`, deducting from the caller's
         * allowance.
         *
         * See {ERC20-_burn} and {ERC20-allowance}.
         *
         * Requirements:
         *
         * - the caller must have allowance for ``accounts``'s tokens of at least
         * `amount`.
         */
        function burnFrom(address account, uint256 amount) public virtual {
            uint256 currentAllowance = allowance(account, _msgSender());
            require(currentAllowance >= amount, "ERC20: burn amount exceeds allowance");
            unchecked {
                _approve(account, _msgSender(), currentAllowance - amount);
            }
            _burn(account, amount);
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    import "../utils/Context.sol";
    /**
     * @dev Contract module which allows children to implement an emergency stop
     * mechanism that can be triggered by an authorized account.
     *
     * This module is used through inheritance. It will make available the
     * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
     * the functions of your contract. Note that they will not be pausable by
     * simply including this module, only once the modifiers are put in place.
     */
    abstract contract Pausable is Context {
        /**
         * @dev Emitted when the pause is triggered by `account`.
         */
        event Paused(address account);
        /**
         * @dev Emitted when the pause is lifted by `account`.
         */
        event Unpaused(address account);
        bool private _paused;
        /**
         * @dev Initializes the contract in unpaused state.
         */
        constructor() {
            _paused = false;
        }
        /**
         * @dev Returns true if the contract is paused, and false otherwise.
         */
        function paused() public view virtual returns (bool) {
            return _paused;
        }
        /**
         * @dev Modifier to make a function callable only when the contract is not paused.
         *
         * Requirements:
         *
         * - The contract must not be paused.
         */
        modifier whenNotPaused() {
            require(!paused(), "Pausable: paused");
            _;
        }
        /**
         * @dev Modifier to make a function callable only when the contract is paused.
         *
         * Requirements:
         *
         * - The contract must be paused.
         */
        modifier whenPaused() {
            require(paused(), "Pausable: not paused");
            _;
        }
        /**
         * @dev Triggers stopped state.
         *
         * Requirements:
         *
         * - The contract must not be paused.
         */
        function _pause() internal virtual whenNotPaused {
            _paused = true;
            emit Paused(_msgSender());
        }
        /**
         * @dev Returns to normal state.
         *
         * Requirements:
         *
         * - The contract must be paused.
         */
        function _unpause() internal virtual whenPaused {
            _paused = false;
            emit Unpaused(_msgSender());
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    import "../utils/Context.sol";
    /**
     * @dev Contract module which provides a basic access control mechanism, where
     * there is an account (an owner) that can be granted exclusive access to
     * specific functions.
     *
     * By default, the owner account will be the one that deploys the contract. This
     * can later be changed with {transferOwnership}.
     *
     * This module is used through inheritance. It will make available the modifier
     * `onlyOwner`, which can be applied to your functions to restrict their use to
     * the owner.
     */
    abstract contract Ownable is Context {
        address private _owner;
        event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
        /**
         * @dev Initializes the contract setting the deployer as the initial owner.
         */
        constructor() {
            _setOwner(_msgSender());
        }
        /**
         * @dev Returns the address of the current owner.
         */
        function owner() public view virtual returns (address) {
            return _owner;
        }
        /**
         * @dev Throws if called by any account other than the owner.
         */
        modifier onlyOwner() {
            require(owner() == _msgSender(), "Ownable: caller is not the owner");
            _;
        }
        /**
         * @dev Leaves the contract without owner. It will not be possible to call
         * `onlyOwner` functions anymore. Can only be called by the current owner.
         *
         * NOTE: Renouncing ownership will leave the contract without an owner,
         * thereby removing any functionality that is only available to the owner.
         */
        function renounceOwnership() public virtual onlyOwner {
            _setOwner(address(0));
        }
        /**
         * @dev Transfers ownership of the contract to a new account (`newOwner`).
         * Can only be called by the current owner.
         */
        function transferOwnership(address newOwner) public virtual onlyOwner {
            require(newOwner != address(0), "Ownable: new owner is the zero address");
            _setOwner(newOwner);
        }
        function _setOwner(address newOwner) private {
            address oldOwner = _owner;
            _owner = newOwner;
            emit OwnershipTransferred(oldOwner, newOwner);
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    import "./IAccessControl.sol";
    import "../utils/Context.sol";
    import "../utils/Strings.sol";
    import "../utils/introspection/ERC165.sol";
    /**
     * @dev Contract module that allows children to implement role-based access
     * control mechanisms. This is a lightweight version that doesn't allow enumerating role
     * members except through off-chain means by accessing the contract event logs. Some
     * applications may benefit from on-chain enumerability, for those cases see
     * {AccessControlEnumerable}.
     *
     * Roles are referred to by their `bytes32` identifier. These should be exposed
     * in the external API and be unique. The best way to achieve this is by
     * using `public constant` hash digests:
     *
     * ```
     * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
     * ```
     *
     * Roles can be used to represent a set of permissions. To restrict access to a
     * function call, use {hasRole}:
     *
     * ```
     * function foo() public {
     *     require(hasRole(MY_ROLE, msg.sender));
     *     ...
     * }
     * ```
     *
     * Roles can be granted and revoked dynamically via the {grantRole} and
     * {revokeRole} functions. Each role has an associated admin role, and only
     * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
     *
     * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
     * that only accounts with this role will be able to grant or revoke other
     * roles. More complex role relationships can be created by using
     * {_setRoleAdmin}.
     *
     * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
     * grant and revoke this role. Extra precautions should be taken to secure
     * accounts that have been granted it.
     */
    abstract contract AccessControl is Context, IAccessControl, ERC165 {
        struct RoleData {
            mapping(address => bool) members;
            bytes32 adminRole;
        }
        mapping(bytes32 => RoleData) private _roles;
        bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
        /**
         * @dev Modifier that checks that an account has a specific role. Reverts
         * with a standardized message including the required role.
         *
         * The format of the revert reason is given by the following regular expression:
         *
         *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
         *
         * _Available since v4.1._
         */
        modifier onlyRole(bytes32 role) {
            _checkRole(role, _msgSender());
            _;
        }
        /**
         * @dev See {IERC165-supportsInterface}.
         */
        function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
            return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId);
        }
        /**
         * @dev Returns `true` if `account` has been granted `role`.
         */
        function hasRole(bytes32 role, address account) public view override returns (bool) {
            return _roles[role].members[account];
        }
        /**
         * @dev Revert with a standard message if `account` is missing `role`.
         *
         * The format of the revert reason is given by the following regular expression:
         *
         *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
         */
        function _checkRole(bytes32 role, address account) internal view {
            if (!hasRole(role, account)) {
                revert(
                    string(
                        abi.encodePacked(
                            "AccessControl: account ",
                            Strings.toHexString(uint160(account), 20),
                            " is missing role ",
                            Strings.toHexString(uint256(role), 32)
                        )
                    )
                );
            }
        }
        /**
         * @dev Returns the admin role that controls `role`. See {grantRole} and
         * {revokeRole}.
         *
         * To change a role's admin, use {_setRoleAdmin}.
         */
        function getRoleAdmin(bytes32 role) public view override returns (bytes32) {
            return _roles[role].adminRole;
        }
        /**
         * @dev Grants `role` to `account`.
         *
         * If `account` had not been already granted `role`, emits a {RoleGranted}
         * event.
         *
         * Requirements:
         *
         * - the caller must have ``role``'s admin role.
         */
        function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
            _grantRole(role, account);
        }
        /**
         * @dev Revokes `role` from `account`.
         *
         * If `account` had been granted `role`, emits a {RoleRevoked} event.
         *
         * Requirements:
         *
         * - the caller must have ``role``'s admin role.
         */
        function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
            _revokeRole(role, account);
        }
        /**
         * @dev Revokes `role` from the calling account.
         *
         * Roles are often managed via {grantRole} and {revokeRole}: this function's
         * purpose is to provide a mechanism for accounts to lose their privileges
         * if they are compromised (such as when a trusted device is misplaced).
         *
         * If the calling account had been granted `role`, emits a {RoleRevoked}
         * event.
         *
         * Requirements:
         *
         * - the caller must be `account`.
         */
        function renounceRole(bytes32 role, address account) public virtual override {
            require(account == _msgSender(), "AccessControl: can only renounce roles for self");
            _revokeRole(role, account);
        }
        /**
         * @dev Grants `role` to `account`.
         *
         * If `account` had not been already granted `role`, emits a {RoleGranted}
         * event. Note that unlike {grantRole}, this function doesn't perform any
         * checks on the calling account.
         *
         * [WARNING]
         * ====
         * This function should only be called from the constructor when setting
         * up the initial roles for the system.
         *
         * Using this function in any other way is effectively circumventing the admin
         * system imposed by {AccessControl}.
         * ====
         */
        function _setupRole(bytes32 role, address account) internal virtual {
            _grantRole(role, account);
        }
        /**
         * @dev Sets `adminRole` as ``role``'s admin role.
         *
         * Emits a {RoleAdminChanged} event.
         */
        function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
            bytes32 previousAdminRole = getRoleAdmin(role);
            _roles[role].adminRole = adminRole;
            emit RoleAdminChanged(role, previousAdminRole, adminRole);
        }
        function _grantRole(bytes32 role, address account) private {
            if (!hasRole(role, account)) {
                _roles[role].members[account] = true;
                emit RoleGranted(role, account, _msgSender());
            }
        }
        function _revokeRole(bytes32 role, address account) private {
            if (hasRole(role, account)) {
                _roles[role].members[account] = false;
                emit RoleRevoked(role, account, _msgSender());
            }
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    import "../IERC20.sol";
    /**
     * @dev Interface for the optional metadata functions from the ERC20 standard.
     *
     * _Available since v4.1._
     */
    interface IERC20Metadata is IERC20 {
        /**
         * @dev Returns the name of the token.
         */
        function name() external view returns (string memory);
        /**
         * @dev Returns the symbol of the token.
         */
        function symbol() external view returns (string memory);
        /**
         * @dev Returns the decimals places of the token.
         */
        function decimals() external view returns (uint8);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    /**
     * @dev Provides information about the current execution context, including the
     * sender of the transaction and its data. While these are generally available
     * via msg.sender and msg.data, they should not be accessed in such a direct
     * manner, since when dealing with meta-transactions the account sending and
     * paying for execution may not be the actual sender (as far as an application
     * is concerned).
     *
     * This contract is only required for intermediate, library-like contracts.
     */
    abstract contract Context {
        function _msgSender() internal view virtual returns (address) {
            return msg.sender;
        }
        function _msgData() internal view virtual returns (bytes calldata) {
            return msg.data;
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    /**
     * @dev External interface of AccessControl declared to support ERC165 detection.
     */
    interface IAccessControl {
        /**
         * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
         *
         * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
         * {RoleAdminChanged} not being emitted signaling this.
         *
         * _Available since v3.1._
         */
        event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
        /**
         * @dev Emitted when `account` is granted `role`.
         *
         * `sender` is the account that originated the contract call, an admin role
         * bearer except when using {AccessControl-_setupRole}.
         */
        event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
        /**
         * @dev Emitted when `account` is revoked `role`.
         *
         * `sender` is the account that originated the contract call:
         *   - if using `revokeRole`, it is the admin role bearer
         *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
         */
        event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
        /**
         * @dev Returns `true` if `account` has been granted `role`.
         */
        function hasRole(bytes32 role, address account) external view returns (bool);
        /**
         * @dev Returns the admin role that controls `role`. See {grantRole} and
         * {revokeRole}.
         *
         * To change a role's admin, use {AccessControl-_setRoleAdmin}.
         */
        function getRoleAdmin(bytes32 role) external view returns (bytes32);
        /**
         * @dev Grants `role` to `account`.
         *
         * If `account` had not been already granted `role`, emits a {RoleGranted}
         * event.
         *
         * Requirements:
         *
         * - the caller must have ``role``'s admin role.
         */
        function grantRole(bytes32 role, address account) external;
        /**
         * @dev Revokes `role` from `account`.
         *
         * If `account` had been granted `role`, emits a {RoleRevoked} event.
         *
         * Requirements:
         *
         * - the caller must have ``role``'s admin role.
         */
        function revokeRole(bytes32 role, address account) external;
        /**
         * @dev Revokes `role` from the calling account.
         *
         * Roles are often managed via {grantRole} and {revokeRole}: this function's
         * purpose is to provide a mechanism for accounts to lose their privileges
         * if they are compromised (such as when a trusted device is misplaced).
         *
         * If the calling account had been granted `role`, emits a {RoleRevoked}
         * event.
         *
         * Requirements:
         *
         * - the caller must be `account`.
         */
        function renounceRole(bytes32 role, address account) external;
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    /**
     * @dev String operations.
     */
    library Strings {
        bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
        /**
         * @dev Converts a `uint256` to its ASCII `string` decimal representation.
         */
        function toString(uint256 value) internal pure returns (string memory) {
            // Inspired by OraclizeAPI's implementation - MIT licence
            // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
            if (value == 0) {
                return "0";
            }
            uint256 temp = value;
            uint256 digits;
            while (temp != 0) {
                digits++;
                temp /= 10;
            }
            bytes memory buffer = new bytes(digits);
            while (value != 0) {
                digits -= 1;
                buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
                value /= 10;
            }
            return string(buffer);
        }
        /**
         * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
         */
        function toHexString(uint256 value) internal pure returns (string memory) {
            if (value == 0) {
                return "0x00";
            }
            uint256 temp = value;
            uint256 length = 0;
            while (temp != 0) {
                length++;
                temp >>= 8;
            }
            return toHexString(value, length);
        }
        /**
         * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
         */
        function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
            bytes memory buffer = new bytes(2 * length + 2);
            buffer[0] = "0";
            buffer[1] = "x";
            for (uint256 i = 2 * length + 1; i > 1; --i) {
                buffer[i] = _HEX_SYMBOLS[value & 0xf];
                value >>= 4;
            }
            require(value == 0, "Strings: hex length insufficient");
            return string(buffer);
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    import "./IERC165.sol";
    /**
     * @dev Implementation of the {IERC165} interface.
     *
     * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
     * for the additional interface id that will be supported. For example:
     *
     * ```solidity
     * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
     *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
     * }
     * ```
     *
     * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
     */
    abstract contract ERC165 is IERC165 {
        /**
         * @dev See {IERC165-supportsInterface}.
         */
        function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
            return interfaceId == type(IERC165).interfaceId;
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    /**
     * @dev Interface of the ERC165 standard, as defined in the
     * https://eips.ethereum.org/EIPS/eip-165[EIP].
     *
     * Implementers can declare support of contract interfaces, which can then be
     * queried by others ({ERC165Checker}).
     *
     * For an implementation, see {ERC165}.
     */
    interface IERC165 {
        /**
         * @dev Returns true if this contract implements the interface defined by
         * `interfaceId`. See the corresponding
         * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
         * to learn more about how these ids are created.
         *
         * This function call must use less than 30 000 gas.
         */
        function supportsInterface(bytes4 interfaceId) external view returns (bool);
    }
    

    File 3 of 4: Dai
    // hevm: flattened sources of /nix/store/8xb41r4qd0cjb63wcrxf1qmfg88p0961-dss-6fd7de0/src/dai.sol
    pragma solidity =0.5.12;
    
    ////// /nix/store/8xb41r4qd0cjb63wcrxf1qmfg88p0961-dss-6fd7de0/src/lib.sol
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    
    /* pragma solidity 0.5.12; */
    
    contract LibNote {
        event LogNote(
            bytes4   indexed  sig,
            address  indexed  usr,
            bytes32  indexed  arg1,
            bytes32  indexed  arg2,
            bytes             data
        ) anonymous;
    
        modifier note {
            _;
            assembly {
                // log an 'anonymous' event with a constant 6 words of calldata
                // and four indexed topics: selector, caller, arg1 and arg2
                let mark := msize                         // end of memory ensures zero
                mstore(0x40, add(mark, 288))              // update free memory pointer
                mstore(mark, 0x20)                        // bytes type data offset
                mstore(add(mark, 0x20), 224)              // bytes size (padded)
                calldatacopy(add(mark, 0x40), 0, 224)     // bytes payload
                log4(mark, 288,                           // calldata
                     shl(224, shr(224, calldataload(0))), // msg.sig
                     caller,                              // msg.sender
                     calldataload(4),                     // arg1
                     calldataload(36)                     // arg2
                    )
            }
        }
    }
    
    ////// /nix/store/8xb41r4qd0cjb63wcrxf1qmfg88p0961-dss-6fd7de0/src/dai.sol
    // Copyright (C) 2017, 2018, 2019 dbrock, rain, mrchico
    
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU Affero General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    //
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU Affero General Public License for more details.
    //
    // You should have received a copy of the GNU Affero General Public License
    // along with this program.  If not, see <https://www.gnu.org/licenses/>.
    
    /* pragma solidity 0.5.12; */
    
    /* import "./lib.sol"; */
    
    contract Dai is LibNote {
        // --- Auth ---
        mapping (address => uint) public wards;
        function rely(address guy) external note auth { wards[guy] = 1; }
        function deny(address guy) external note auth { wards[guy] = 0; }
        modifier auth {
            require(wards[msg.sender] == 1, "Dai/not-authorized");
            _;
        }
    
        // --- ERC20 Data ---
        string  public constant name     = "Dai Stablecoin";
        string  public constant symbol   = "DAI";
        string  public constant version  = "1";
        uint8   public constant decimals = 18;
        uint256 public totalSupply;
    
        mapping (address => uint)                      public balanceOf;
        mapping (address => mapping (address => uint)) public allowance;
        mapping (address => uint)                      public nonces;
    
        event Approval(address indexed src, address indexed guy, uint wad);
        event Transfer(address indexed src, address indexed dst, uint wad);
    
        // --- Math ---
        function add(uint x, uint y) internal pure returns (uint z) {
            require((z = x + y) >= x);
        }
        function sub(uint x, uint y) internal pure returns (uint z) {
            require((z = x - y) <= x);
        }
    
        // --- EIP712 niceties ---
        bytes32 public DOMAIN_SEPARATOR;
        // bytes32 public constant PERMIT_TYPEHASH = keccak256("Permit(address holder,address spender,uint256 nonce,uint256 expiry,bool allowed)");
        bytes32 public constant PERMIT_TYPEHASH = 0xea2aa0a1be11a07ed86d755c93467f4f82362b452371d1ba94d1715123511acb;
    
        constructor(uint256 chainId_) public {
            wards[msg.sender] = 1;
            DOMAIN_SEPARATOR = keccak256(abi.encode(
                keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"),
                keccak256(bytes(name)),
                keccak256(bytes(version)),
                chainId_,
                address(this)
            ));
        }
    
        // --- Token ---
        function transfer(address dst, uint wad) external returns (bool) {
            return transferFrom(msg.sender, dst, wad);
        }
        function transferFrom(address src, address dst, uint wad)
            public returns (bool)
        {
            require(balanceOf[src] >= wad, "Dai/insufficient-balance");
            if (src != msg.sender && allowance[src][msg.sender] != uint(-1)) {
                require(allowance[src][msg.sender] >= wad, "Dai/insufficient-allowance");
                allowance[src][msg.sender] = sub(allowance[src][msg.sender], wad);
            }
            balanceOf[src] = sub(balanceOf[src], wad);
            balanceOf[dst] = add(balanceOf[dst], wad);
            emit Transfer(src, dst, wad);
            return true;
        }
        function mint(address usr, uint wad) external auth {
            balanceOf[usr] = add(balanceOf[usr], wad);
            totalSupply    = add(totalSupply, wad);
            emit Transfer(address(0), usr, wad);
        }
        function burn(address usr, uint wad) external {
            require(balanceOf[usr] >= wad, "Dai/insufficient-balance");
            if (usr != msg.sender && allowance[usr][msg.sender] != uint(-1)) {
                require(allowance[usr][msg.sender] >= wad, "Dai/insufficient-allowance");
                allowance[usr][msg.sender] = sub(allowance[usr][msg.sender], wad);
            }
            balanceOf[usr] = sub(balanceOf[usr], wad);
            totalSupply    = sub(totalSupply, wad);
            emit Transfer(usr, address(0), wad);
        }
        function approve(address usr, uint wad) external returns (bool) {
            allowance[msg.sender][usr] = wad;
            emit Approval(msg.sender, usr, wad);
            return true;
        }
    
        // --- Alias ---
        function push(address usr, uint wad) external {
            transferFrom(msg.sender, usr, wad);
        }
        function pull(address usr, uint wad) external {
            transferFrom(usr, msg.sender, wad);
        }
        function move(address src, address dst, uint wad) external {
            transferFrom(src, dst, wad);
        }
    
        // --- Approve by signature ---
        function permit(address holder, address spender, uint256 nonce, uint256 expiry,
                        bool allowed, uint8 v, bytes32 r, bytes32 s) external
        {
            bytes32 digest =
                keccak256(abi.encodePacked(
                    "\x19\x01",
                    DOMAIN_SEPARATOR,
                    keccak256(abi.encode(PERMIT_TYPEHASH,
                                         holder,
                                         spender,
                                         nonce,
                                         expiry,
                                         allowed))
            ));
    
            require(holder != address(0), "Dai/invalid-address-0");
            require(holder == ecrecover(digest, v, r, s), "Dai/invalid-permit");
            require(expiry == 0 || now <= expiry, "Dai/permit-expired");
            require(nonce == nonces[holder]++, "Dai/invalid-nonce");
            uint wad = allowed ? uint(-1) : 0;
            allowance[holder][spender] = wad;
            emit Approval(holder, spender, wad);
        }
    }

    File 4 of 4: WeightedPool
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "./BaseWeightedPool.sol";
    import "./WeightedPoolProtocolFees.sol";
    /**
     * @dev Basic Weighted Pool with immutable weights.
     */
    contract WeightedPool is BaseWeightedPool, WeightedPoolProtocolFees {
        using FixedPoint for uint256;
        uint256 private constant _MAX_TOKENS = 8;
        uint256 private immutable _totalTokens;
        string private _version;
        IERC20 internal immutable _token0;
        IERC20 internal immutable _token1;
        IERC20 internal immutable _token2;
        IERC20 internal immutable _token3;
        IERC20 internal immutable _token4;
        IERC20 internal immutable _token5;
        IERC20 internal immutable _token6;
        IERC20 internal immutable _token7;
        // All token balances are normalized to behave as if the token had 18 decimals. We assume a token's decimals will
        // not change throughout its lifetime, and store the corresponding scaling factor for each at construction time.
        // These factors are always greater than or equal to one: tokens with more than 18 decimals are not supported.
        uint256 internal immutable _scalingFactor0;
        uint256 internal immutable _scalingFactor1;
        uint256 internal immutable _scalingFactor2;
        uint256 internal immutable _scalingFactor3;
        uint256 internal immutable _scalingFactor4;
        uint256 internal immutable _scalingFactor5;
        uint256 internal immutable _scalingFactor6;
        uint256 internal immutable _scalingFactor7;
        uint256 internal immutable _normalizedWeight0;
        uint256 internal immutable _normalizedWeight1;
        uint256 internal immutable _normalizedWeight2;
        uint256 internal immutable _normalizedWeight3;
        uint256 internal immutable _normalizedWeight4;
        uint256 internal immutable _normalizedWeight5;
        uint256 internal immutable _normalizedWeight6;
        uint256 internal immutable _normalizedWeight7;
        struct NewPoolParams {
            string name;
            string symbol;
            IERC20[] tokens;
            uint256[] normalizedWeights;
            IRateProvider[] rateProviders;
            address[] assetManagers;
            uint256 swapFeePercentage;
        }
        constructor(
            NewPoolParams memory params,
            IVault vault,
            IProtocolFeePercentagesProvider protocolFeeProvider,
            uint256 pauseWindowDuration,
            uint256 bufferPeriodDuration,
            address owner,
            string memory version
        )
            BaseWeightedPool(
                vault,
                params.name,
                params.symbol,
                params.tokens,
                params.assetManagers,
                params.swapFeePercentage,
                pauseWindowDuration,
                bufferPeriodDuration,
                owner,
                false
            )
            ProtocolFeeCache(protocolFeeProvider, ProtocolFeeCache.DELEGATE_PROTOCOL_SWAP_FEES_SENTINEL)
            WeightedPoolProtocolFees(params.tokens.length, params.rateProviders)
        {
            uint256 numTokens = params.tokens.length;
            InputHelpers.ensureInputLengthMatch(numTokens, params.normalizedWeights.length);
            _totalTokens = numTokens;
            _version = version;
            // Ensure each normalized weight is above the minimum
            uint256 normalizedSum = 0;
            for (uint8 i = 0; i < numTokens; i++) {
                uint256 normalizedWeight = params.normalizedWeights[i];
                _require(normalizedWeight >= WeightedMath._MIN_WEIGHT, Errors.MIN_WEIGHT);
                normalizedSum = normalizedSum.add(normalizedWeight);
            }
            // Ensure that the normalized weights sum to ONE
            _require(normalizedSum == FixedPoint.ONE, Errors.NORMALIZED_WEIGHT_INVARIANT);
            // Immutable variables cannot be initialized inside an if statement, so we must do conditional assignments
            _token0 = params.tokens[0];
            _token1 = params.tokens[1];
            _token2 = numTokens > 2 ? params.tokens[2] : IERC20(0);
            _token3 = numTokens > 3 ? params.tokens[3] : IERC20(0);
            _token4 = numTokens > 4 ? params.tokens[4] : IERC20(0);
            _token5 = numTokens > 5 ? params.tokens[5] : IERC20(0);
            _token6 = numTokens > 6 ? params.tokens[6] : IERC20(0);
            _token7 = numTokens > 7 ? params.tokens[7] : IERC20(0);
            _scalingFactor0 = _computeScalingFactor(params.tokens[0]);
            _scalingFactor1 = _computeScalingFactor(params.tokens[1]);
            _scalingFactor2 = numTokens > 2 ? _computeScalingFactor(params.tokens[2]) : 0;
            _scalingFactor3 = numTokens > 3 ? _computeScalingFactor(params.tokens[3]) : 0;
            _scalingFactor4 = numTokens > 4 ? _computeScalingFactor(params.tokens[4]) : 0;
            _scalingFactor5 = numTokens > 5 ? _computeScalingFactor(params.tokens[5]) : 0;
            _scalingFactor6 = numTokens > 6 ? _computeScalingFactor(params.tokens[6]) : 0;
            _scalingFactor7 = numTokens > 7 ? _computeScalingFactor(params.tokens[7]) : 0;
            _normalizedWeight0 = params.normalizedWeights[0];
            _normalizedWeight1 = params.normalizedWeights[1];
            _normalizedWeight2 = numTokens > 2 ? params.normalizedWeights[2] : 0;
            _normalizedWeight3 = numTokens > 3 ? params.normalizedWeights[3] : 0;
            _normalizedWeight4 = numTokens > 4 ? params.normalizedWeights[4] : 0;
            _normalizedWeight5 = numTokens > 5 ? params.normalizedWeights[5] : 0;
            _normalizedWeight6 = numTokens > 6 ? params.normalizedWeights[6] : 0;
            _normalizedWeight7 = numTokens > 7 ? params.normalizedWeights[7] : 0;
        }
        /**
         * @dev Ensure we are not in a Vault context when this function is called, by attempting a no-op internal
         * balance operation. If we are already in a Vault transaction (e.g., a swap, join, or exit), the Vault's
         * reentrancy protection will cause this function to revert.
         *
         * The exact function call doesn't really matter: we're just trying to trigger the Vault reentrancy check
         * (and not hurt anything in case it works). An empty operation array with no specific operation at all works
         * for that purpose, and is also the least expensive in terms of gas and bytecode size.
         *
         * Use this modifier with any function that can cause a state change in a pool and is either public itself,
         * or called by a public function *outside* a Vault operation (e.g., join, exit, or swap).
         * See https://forum.balancer.fi/t/reentrancy-vulnerability-scope-expanded/4345 for reference.
         */
        modifier whenNotInVaultContext() {
            _ensureNotInVaultContext();
            _;
        }
        /**
         * @dev Reverts if called in the middle of a Vault operation; has no effect otherwise.
         */
        function _ensureNotInVaultContext() private {
            IVault.UserBalanceOp[] memory noop = new IVault.UserBalanceOp[](0);
            getVault().manageUserBalance(noop);
        }
        function _getNormalizedWeight(IERC20 token) internal view virtual override returns (uint256) {
            // prettier-ignore
            if (token == _token0) { return _normalizedWeight0; }
            else if (token == _token1) { return _normalizedWeight1; }
            else if (token == _token2) { return _normalizedWeight2; }
            else if (token == _token3) { return _normalizedWeight3; }
            else if (token == _token4) { return _normalizedWeight4; }
            else if (token == _token5) { return _normalizedWeight5; }
            else if (token == _token6) { return _normalizedWeight6; }
            else if (token == _token7) { return _normalizedWeight7; }
            else {
                _revert(Errors.INVALID_TOKEN);
            }
        }
        function _getNormalizedWeights() internal view virtual override returns (uint256[] memory) {
            uint256 totalTokens = _getTotalTokens();
            uint256[] memory normalizedWeights = new uint256[](totalTokens);
            // prettier-ignore
            {
                normalizedWeights[0] = _normalizedWeight0;
                normalizedWeights[1] = _normalizedWeight1;
                if (totalTokens > 2) { normalizedWeights[2] = _normalizedWeight2; } else { return normalizedWeights; }
                if (totalTokens > 3) { normalizedWeights[3] = _normalizedWeight3; } else { return normalizedWeights; }
                if (totalTokens > 4) { normalizedWeights[4] = _normalizedWeight4; } else { return normalizedWeights; }
                if (totalTokens > 5) { normalizedWeights[5] = _normalizedWeight5; } else { return normalizedWeights; }
                if (totalTokens > 6) { normalizedWeights[6] = _normalizedWeight6; } else { return normalizedWeights; }
                if (totalTokens > 7) { normalizedWeights[7] = _normalizedWeight7; } else { return normalizedWeights; }
            }
            return normalizedWeights;
        }
        function _getMaxTokens() internal pure virtual override returns (uint256) {
            return _MAX_TOKENS;
        }
        function _getTotalTokens() internal view virtual override returns (uint256) {
            return _totalTokens;
        }
        /**
         * @notice Returns a JSON representation of the contract version containing name, version number and task ID.
         */
        function version() external view returns (string memory) {
            return _version;
        }
        /**
         * @dev Returns the scaling factor for one of the Pool's tokens. Reverts if `token` is not a token registered by the
         * Pool.
         */
        function _scalingFactor(IERC20 token) internal view virtual override returns (uint256) {
            // prettier-ignore
            if (token == _token0) { return _getScalingFactor0(); }
            else if (token == _token1) { return _getScalingFactor1(); }
            else if (token == _token2) { return _getScalingFactor2(); }
            else if (token == _token3) { return _getScalingFactor3(); }
            else if (token == _token4) { return _getScalingFactor4(); }
            else if (token == _token5) { return _getScalingFactor5(); }
            else if (token == _token6) { return _getScalingFactor6(); }
            else if (token == _token7) { return _getScalingFactor7(); }
            else {
                _revert(Errors.INVALID_TOKEN);
            }
        }
        function _scalingFactors() internal view virtual override returns (uint256[] memory) {
            uint256 totalTokens = _getTotalTokens();
            uint256[] memory scalingFactors = new uint256[](totalTokens);
            // prettier-ignore
            {
                scalingFactors[0] = _getScalingFactor0();
                scalingFactors[1] = _getScalingFactor1();
                if (totalTokens > 2) { scalingFactors[2] = _getScalingFactor2(); } else { return scalingFactors; }
                if (totalTokens > 3) { scalingFactors[3] = _getScalingFactor3(); } else { return scalingFactors; }
                if (totalTokens > 4) { scalingFactors[4] = _getScalingFactor4(); } else { return scalingFactors; }
                if (totalTokens > 5) { scalingFactors[5] = _getScalingFactor5(); } else { return scalingFactors; }
                if (totalTokens > 6) { scalingFactors[6] = _getScalingFactor6(); } else { return scalingFactors; }
                if (totalTokens > 7) { scalingFactors[7] = _getScalingFactor7(); } else { return scalingFactors; }
            }
            return scalingFactors;
        }
        // Initialize
        function _onInitializePool(
            bytes32 poolId,
            address sender,
            address recipient,
            uint256[] memory scalingFactors,
            bytes memory userData
        ) internal virtual override returns (uint256, uint256[] memory) {
            // Initialize `_athRateProduct` if the Pool will pay protocol fees on yield.
            // Not initializing this here properly will cause all joins/exits to revert.
            if (!_isExemptFromYieldProtocolFees()) _updateATHRateProduct(_getRateProduct(_getNormalizedWeights()));
            return super._onInitializePool(poolId, sender, recipient, scalingFactors, userData);
        }
        // WeightedPoolProtocolFees functions
        function _beforeJoinExit(uint256[] memory preBalances, uint256[] memory normalizedWeights)
            internal
            virtual
            override
            returns (uint256, uint256)
        {
            uint256 supplyBeforeFeeCollection = totalSupply();
            uint256 invariant = WeightedMath._calculateInvariant(normalizedWeights, preBalances);
            (uint256 protocolFeesToBeMinted, uint256 athRateProduct) = _getPreJoinExitProtocolFees(
                invariant,
                normalizedWeights,
                supplyBeforeFeeCollection
            );
            // We then update the recorded value of `athRateProduct` to ensure we only collect fees on yield once.
            // A zero value for `athRateProduct` represents that it is unchanged so we can skip updating it.
            if (athRateProduct > 0) {
                _updateATHRateProduct(athRateProduct);
            }
            if (protocolFeesToBeMinted > 0) {
                _payProtocolFees(protocolFeesToBeMinted);
            }
            return (supplyBeforeFeeCollection.add(protocolFeesToBeMinted), invariant);
        }
        function _afterJoinExit(
            uint256 preJoinExitInvariant,
            uint256[] memory preBalances,
            uint256[] memory balanceDeltas,
            uint256[] memory normalizedWeights,
            uint256 preJoinExitSupply,
            uint256 postJoinExitSupply
        ) internal virtual override {
            uint256 protocolFeesToBeMinted = _getPostJoinExitProtocolFees(
                preJoinExitInvariant,
                preBalances,
                balanceDeltas,
                normalizedWeights,
                preJoinExitSupply,
                postJoinExitSupply
            );
            if (protocolFeesToBeMinted > 0) {
                _payProtocolFees(protocolFeesToBeMinted);
            }
        }
        function _updatePostJoinExit(uint256 postJoinExitInvariant)
            internal
            virtual
            override(BaseWeightedPool, WeightedPoolProtocolFees)
        {
            WeightedPoolProtocolFees._updatePostJoinExit(postJoinExitInvariant);
        }
        /**
         * @dev This function will revert when called within a Vault context (i.e. in the middle of a join or an exit).
         *
         * This function depends on the invariant value, which may be calculated incorrectly in the middle of a join or
         * an exit, because the state of the pool could be out of sync with the state of the Vault. The modifier
         * `whenNotInVaultContext` prevents calling this function (and in turn, the external
         * `updateProtocolFeePercentageCache`) in such a context.
         *
         * See https://forum.balancer.fi/t/reentrancy-vulnerability-scope-expanded/4345 for reference.
         */
        function _beforeProtocolFeeCacheUpdate() internal override whenNotInVaultContext {
            // The `getRate()` function depends on the actual supply, which in turn depends on the cached protocol fee
            // percentages. Changing these would therefore result in the rate changing, which is not acceptable as this is a
            // sensitive value.
            // Because of this, we pay any due protocol fees *before* updating the cache, making it so that the new
            // percentages only affect future operation of the Pool, and not past fees. As a result, `getRate()` is
            // unaffected by the cached protocol fee percentages changing.
            // Given that this operation is state-changing and relatively complex, we only allow it as long as the Pool is
            // not paused.
            _ensureNotPaused();
            uint256 invariant = getInvariant();
            (uint256 protocolFeesToBeMinted, uint256 athRateProduct) = _getPreJoinExitProtocolFees(
                invariant,
                _getNormalizedWeights(),
                totalSupply()
            );
            if (protocolFeesToBeMinted > 0) {
                _payProtocolFees(protocolFeesToBeMinted);
            }
            // With the fees paid, we now store the current invariant and update the ATH rate product (if necessary),
            // marking the Pool as free of protocol debt.
            _updatePostJoinExit(invariant);
            if (athRateProduct > 0) {
                _updateATHRateProduct(athRateProduct);
            }
        }
        /**
         * @notice Returns the effective BPT supply.
         *
         * @dev This would be the same as `totalSupply` however the Pool owes debt to the Protocol in the form of unminted
         * BPT, which will be minted immediately before the next join or exit. We need to take these into account since,
         * even if they don't yet exist, they will effectively be included in any Pool operation that involves BPT.
         *
         * In the vast majority of cases, this function should be used instead of `totalSupply()`.
         *
         * **IMPORTANT NOTE**: calling this function within a Vault context (i.e. in the middle of a join or an exit) is
         * potentially unsafe, since the returned value is manipulable. It is up to the caller to ensure safety.
         *
         * This is because this function calculates the invariant, which requires the state of the pool to be in sync
         * with the state of the Vault. That condition may not be true in the middle of a join or an exit.
         *
         * To call this function safely, attempt to trigger the reentrancy guard in the Vault by calling a non-reentrant
         * function before calling `getActualSupply`. That will make the transaction revert in an unsafe context.
         * (See `whenNotInVaultContext` in `WeightedPool`).
         *
         * See https://forum.balancer.fi/t/reentrancy-vulnerability-scope-expanded/4345 for reference.
         */
        function getActualSupply() external view returns (uint256) {
            uint256 supply = totalSupply();
            (uint256 protocolFeesToBeMinted, ) = _getPreJoinExitProtocolFees(
                getInvariant(),
                _getNormalizedWeights(),
                supply
            );
            return supply.add(protocolFeesToBeMinted);
        }
        /**
         * @dev This function will revert when called within a Vault context (i.e. in the middle of a join or an exit).
         *
         * This function depends on the invariant value, which may be calculated incorrectly in the middle of a join or
         * an exit, because the state of the pool could be out of sync with the state of the Vault.
         *
         * The modifier `whenNotInVaultContext` prevents calling this function (and in turn, the external
         * `disableRecoveryMode`) in such a context.
         *
         * See https://forum.balancer.fi/t/reentrancy-vulnerability-scope-expanded/4345 for reference.
         */
        function _onDisableRecoveryMode() internal override whenNotInVaultContext {
            // Update the postJoinExitInvariant to the value of the currentInvariant, zeroing out any protocol swap fees.
            _updatePostJoinExit(getInvariant());
            // If the Pool has any protocol yield fees accrued then we update the athRateProduct to zero these out.
            // If the current rate product is less than the athRateProduct then we do not perform this update.
            // This prevents the Pool from paying protocol fees on the same yield twice if the rate product were to drop.
            if (!_isExemptFromYieldProtocolFees()) {
                uint256 athRateProduct = getATHRateProduct();
                uint256 rateProduct = _getRateProduct(_getNormalizedWeights());
                if (rateProduct > athRateProduct) {
                    _updateATHRateProduct(rateProduct);
                }
            }
        }
        function _getScalingFactor0() internal view returns (uint256) {
            return _scalingFactor0;
        }
        function _getScalingFactor1() internal view returns (uint256) {
            return _scalingFactor1;
        }
        function _getScalingFactor2() internal view returns (uint256) {
            return _scalingFactor2;
        }
        function _getScalingFactor3() internal view returns (uint256) {
            return _scalingFactor3;
        }
        function _getScalingFactor4() internal view returns (uint256) {
            return _scalingFactor4;
        }
        function _getScalingFactor5() internal view returns (uint256) {
            return _scalingFactor5;
        }
        function _getScalingFactor6() internal view returns (uint256) {
            return _scalingFactor6;
        }
        function _getScalingFactor7() internal view returns (uint256) {
            return _scalingFactor7;
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "@balancer-labs/v2-interfaces/contracts/pool-weighted/WeightedPoolUserData.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/math/FixedPoint.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/helpers/InputHelpers.sol";
    import "@balancer-labs/v2-pool-utils/contracts/BaseMinimalSwapInfoPool.sol";
    import "./WeightedMath.sol";
    /**
     * @dev Base class for WeightedPools containing swap, join and exit logic, but leaving storage and management of
     * the weights to subclasses. Derived contracts can choose to make weights immutable, mutable, or even dynamic
     *  based on local or external logic.
     */
    abstract contract BaseWeightedPool is BaseMinimalSwapInfoPool {
        using FixedPoint for uint256;
        using WeightedPoolUserData for bytes;
        constructor(
            IVault vault,
            string memory name,
            string memory symbol,
            IERC20[] memory tokens,
            address[] memory assetManagers,
            uint256 swapFeePercentage,
            uint256 pauseWindowDuration,
            uint256 bufferPeriodDuration,
            address owner,
            bool mutableTokens
        )
            BasePool(
                vault,
                // Given BaseMinimalSwapInfoPool supports both of these specializations, and this Pool never registers
                // or deregisters any tokens after construction, picking Two Token when the Pool only has two tokens is free
                // gas savings.
                // If the pool is expected to be able register new tokens in future, we must choose MINIMAL_SWAP_INFO
                // as clearly the TWO_TOKEN specification doesn't support adding extra tokens in future.
                tokens.length == 2 && !mutableTokens
                    ? IVault.PoolSpecialization.TWO_TOKEN
                    : IVault.PoolSpecialization.MINIMAL_SWAP_INFO,
                name,
                symbol,
                tokens,
                assetManagers,
                swapFeePercentage,
                pauseWindowDuration,
                bufferPeriodDuration,
                owner
            )
        {
            // solhint-disable-previous-line no-empty-blocks
        }
        // Virtual functions
        /**
         * @dev Returns the normalized weight of `token`. Weights are fixed point numbers that sum to FixedPoint.ONE.
         */
        function _getNormalizedWeight(IERC20 token) internal view virtual returns (uint256);
        /**
         * @dev Returns all normalized weights, in the same order as the Pool's tokens.
         */
        function _getNormalizedWeights() internal view virtual returns (uint256[] memory);
        /**
         * @dev Returns the current value of the invariant.
         *
         * **IMPORTANT NOTE**: calling this function within a Vault context (i.e. in the middle of a join or an exit) is
         * potentially unsafe, since the returned value is manipulable. It is up to the caller to ensure safety.
         *
         * Calculating the invariant requires the state of the pool to be in sync with the state of the Vault.
         * That condition may not be true in the middle of a join or an exit.
         *
         * To call this function safely, attempt to trigger the reentrancy guard in the Vault by calling a non-reentrant
         * function before calling `getInvariant`. That will make the transaction revert in an unsafe context.
         * (See `whenNotInVaultContext` in `WeightedPool`).
         *
         * See https://forum.balancer.fi/t/reentrancy-vulnerability-scope-expanded/4345 for reference.
         */
        function getInvariant() public view returns (uint256) {
            (, uint256[] memory balances, ) = getVault().getPoolTokens(getPoolId());
            // Since the Pool hooks always work with upscaled balances, we manually
            // upscale here for consistency
            _upscaleArray(balances, _scalingFactors());
            uint256[] memory normalizedWeights = _getNormalizedWeights();
            return WeightedMath._calculateInvariant(normalizedWeights, balances);
        }
        function getNormalizedWeights() external view returns (uint256[] memory) {
            return _getNormalizedWeights();
        }
        // Base Pool handlers
        // Swap
        function _onSwapGivenIn(
            SwapRequest memory swapRequest,
            uint256 currentBalanceTokenIn,
            uint256 currentBalanceTokenOut
        ) internal virtual override returns (uint256) {
            return
                WeightedMath._calcOutGivenIn(
                    currentBalanceTokenIn,
                    _getNormalizedWeight(swapRequest.tokenIn),
                    currentBalanceTokenOut,
                    _getNormalizedWeight(swapRequest.tokenOut),
                    swapRequest.amount
                );
        }
        function _onSwapGivenOut(
            SwapRequest memory swapRequest,
            uint256 currentBalanceTokenIn,
            uint256 currentBalanceTokenOut
        ) internal virtual override returns (uint256) {
            return
                WeightedMath._calcInGivenOut(
                    currentBalanceTokenIn,
                    _getNormalizedWeight(swapRequest.tokenIn),
                    currentBalanceTokenOut,
                    _getNormalizedWeight(swapRequest.tokenOut),
                    swapRequest.amount
                );
        }
        /**
         * @dev Called before any join or exit operation. Returns the Pool's total supply by default, but derived contracts
         * may choose to add custom behavior at these steps. This often has to do with protocol fee processing.
         */
        function _beforeJoinExit(uint256[] memory preBalances, uint256[] memory normalizedWeights)
            internal
            virtual
            returns (uint256, uint256)
        {
            return (totalSupply(), WeightedMath._calculateInvariant(normalizedWeights, preBalances));
        }
        /**
         * @dev Called after any regular join or exit operation. Empty by default, but derived contracts
         * may choose to add custom behavior at these steps. This often has to do with protocol fee processing.
         *
         * If performing a join operation, balanceDeltas are the amounts in: otherwise they are the amounts out.
         *
         * This function is free to mutate the `preBalances` array.
         */
        function _afterJoinExit(
            uint256 preJoinExitInvariant,
            uint256[] memory preBalances,
            uint256[] memory balanceDeltas,
            uint256[] memory normalizedWeights,
            uint256 preJoinExitSupply,
            uint256 postJoinExitSupply
        ) internal virtual {
            // solhint-disable-previous-line no-empty-blocks
        }
        // Derived contracts may call this to update state after a join or exit.
        function _updatePostJoinExit(uint256 postJoinExitInvariant) internal virtual {
            // solhint-disable-previous-line no-empty-blocks
        }
        // Initialize
        function _onInitializePool(
            bytes32,
            address,
            address,
            uint256[] memory scalingFactors,
            bytes memory userData
        ) internal virtual override returns (uint256, uint256[] memory) {
            WeightedPoolUserData.JoinKind kind = userData.joinKind();
            _require(kind == WeightedPoolUserData.JoinKind.INIT, Errors.UNINITIALIZED);
            uint256[] memory amountsIn = userData.initialAmountsIn();
            InputHelpers.ensureInputLengthMatch(amountsIn.length, scalingFactors.length);
            _upscaleArray(amountsIn, scalingFactors);
            uint256[] memory normalizedWeights = _getNormalizedWeights();
            uint256 invariantAfterJoin = WeightedMath._calculateInvariant(normalizedWeights, amountsIn);
            // Set the initial BPT to the value of the invariant times the number of tokens. This makes BPT supply more
            // consistent in Pools with similar compositions but different number of tokens.
            uint256 bptAmountOut = Math.mul(invariantAfterJoin, amountsIn.length);
            // Initialization is still a join, so we need to do post-join work. Since we are not paying protocol fees,
            // and all we need to do is update the invariant, call `_updatePostJoinExit` here instead of `_afterJoinExit`.
            _updatePostJoinExit(invariantAfterJoin);
            return (bptAmountOut, amountsIn);
        }
        // Join
        function _onJoinPool(
            bytes32,
            address sender,
            address,
            uint256[] memory balances,
            uint256,
            uint256,
            uint256[] memory scalingFactors,
            bytes memory userData
        ) internal virtual override returns (uint256, uint256[] memory) {
            uint256[] memory normalizedWeights = _getNormalizedWeights();
            (uint256 preJoinExitSupply, uint256 preJoinExitInvariant) = _beforeJoinExit(balances, normalizedWeights);
            (uint256 bptAmountOut, uint256[] memory amountsIn) = _doJoin(
                sender,
                balances,
                normalizedWeights,
                scalingFactors,
                preJoinExitSupply,
                userData
            );
            _afterJoinExit(
                preJoinExitInvariant,
                balances,
                amountsIn,
                normalizedWeights,
                preJoinExitSupply,
                preJoinExitSupply.add(bptAmountOut)
            );
            return (bptAmountOut, amountsIn);
        }
        /**
         * @dev Dispatch code which decodes the provided userdata to perform the specified join type.
         * Inheriting contracts may override this function to add additional join types or extra conditions to allow
         * or disallow joins under certain circumstances.
         */
        function _doJoin(
            address,
            uint256[] memory balances,
            uint256[] memory normalizedWeights,
            uint256[] memory scalingFactors,
            uint256 totalSupply,
            bytes memory userData
        ) internal view virtual returns (uint256, uint256[] memory) {
            WeightedPoolUserData.JoinKind kind = userData.joinKind();
            if (kind == WeightedPoolUserData.JoinKind.EXACT_TOKENS_IN_FOR_BPT_OUT) {
                return _joinExactTokensInForBPTOut(balances, normalizedWeights, scalingFactors, totalSupply, userData);
            } else if (kind == WeightedPoolUserData.JoinKind.TOKEN_IN_FOR_EXACT_BPT_OUT) {
                return _joinTokenInForExactBPTOut(balances, normalizedWeights, totalSupply, userData);
            } else if (kind == WeightedPoolUserData.JoinKind.ALL_TOKENS_IN_FOR_EXACT_BPT_OUT) {
                return _joinAllTokensInForExactBPTOut(balances, totalSupply, userData);
            } else {
                _revert(Errors.UNHANDLED_JOIN_KIND);
            }
        }
        function _joinExactTokensInForBPTOut(
            uint256[] memory balances,
            uint256[] memory normalizedWeights,
            uint256[] memory scalingFactors,
            uint256 totalSupply,
            bytes memory userData
        ) private view returns (uint256, uint256[] memory) {
            (uint256[] memory amountsIn, uint256 minBPTAmountOut) = userData.exactTokensInForBptOut();
            InputHelpers.ensureInputLengthMatch(balances.length, amountsIn.length);
            _upscaleArray(amountsIn, scalingFactors);
            uint256 bptAmountOut = WeightedMath._calcBptOutGivenExactTokensIn(
                balances,
                normalizedWeights,
                amountsIn,
                totalSupply,
                getSwapFeePercentage()
            );
            _require(bptAmountOut >= minBPTAmountOut, Errors.BPT_OUT_MIN_AMOUNT);
            return (bptAmountOut, amountsIn);
        }
        function _joinTokenInForExactBPTOut(
            uint256[] memory balances,
            uint256[] memory normalizedWeights,
            uint256 totalSupply,
            bytes memory userData
        ) private view returns (uint256, uint256[] memory) {
            (uint256 bptAmountOut, uint256 tokenIndex) = userData.tokenInForExactBptOut();
            // Note that there is no maximum amountIn parameter: this is handled by `IVault.joinPool`.
            _require(tokenIndex < balances.length, Errors.OUT_OF_BOUNDS);
            uint256 amountIn = WeightedMath._calcTokenInGivenExactBptOut(
                balances[tokenIndex],
                normalizedWeights[tokenIndex],
                bptAmountOut,
                totalSupply,
                getSwapFeePercentage()
            );
            // We join in a single token, so we initialize amountsIn with zeros
            uint256[] memory amountsIn = new uint256[](balances.length);
            // And then assign the result to the selected token
            amountsIn[tokenIndex] = amountIn;
            return (bptAmountOut, amountsIn);
        }
        function _joinAllTokensInForExactBPTOut(
            uint256[] memory balances,
            uint256 totalSupply,
            bytes memory userData
        ) private pure returns (uint256, uint256[] memory) {
            uint256 bptAmountOut = userData.allTokensInForExactBptOut();
            // Note that there is no maximum amountsIn parameter: this is handled by `IVault.joinPool`.
            uint256[] memory amountsIn = WeightedMath._calcAllTokensInGivenExactBptOut(balances, bptAmountOut, totalSupply);
            return (bptAmountOut, amountsIn);
        }
        // Exit
        function _onExitPool(
            bytes32,
            address sender,
            address,
            uint256[] memory balances,
            uint256,
            uint256,
            uint256[] memory scalingFactors,
            bytes memory userData
        ) internal virtual override returns (uint256, uint256[] memory) {
            uint256[] memory normalizedWeights = _getNormalizedWeights();
            (uint256 preJoinExitSupply, uint256 preJoinExitInvariant) = _beforeJoinExit(balances, normalizedWeights);
            (uint256 bptAmountIn, uint256[] memory amountsOut) = _doExit(
                sender,
                balances,
                normalizedWeights,
                scalingFactors,
                preJoinExitSupply,
                userData
            );
            _afterJoinExit(
                preJoinExitInvariant,
                balances,
                amountsOut,
                normalizedWeights,
                preJoinExitSupply,
                preJoinExitSupply.sub(bptAmountIn)
            );
            return (bptAmountIn, amountsOut);
        }
        /**
         * @dev Dispatch code which decodes the provided userdata to perform the specified exit type.
         * Inheriting contracts may override this function to add additional exit types or extra conditions to allow
         * or disallow exit under certain circumstances.
         */
        function _doExit(
            address,
            uint256[] memory balances,
            uint256[] memory normalizedWeights,
            uint256[] memory scalingFactors,
            uint256 totalSupply,
            bytes memory userData
        ) internal view virtual returns (uint256, uint256[] memory) {
            WeightedPoolUserData.ExitKind kind = userData.exitKind();
            if (kind == WeightedPoolUserData.ExitKind.EXACT_BPT_IN_FOR_ONE_TOKEN_OUT) {
                return _exitExactBPTInForTokenOut(balances, normalizedWeights, totalSupply, userData);
            } else if (kind == WeightedPoolUserData.ExitKind.EXACT_BPT_IN_FOR_TOKENS_OUT) {
                return _exitExactBPTInForTokensOut(balances, totalSupply, userData);
            } else if (kind == WeightedPoolUserData.ExitKind.BPT_IN_FOR_EXACT_TOKENS_OUT) {
                return _exitBPTInForExactTokensOut(balances, normalizedWeights, scalingFactors, totalSupply, userData);
            } else {
                _revert(Errors.UNHANDLED_EXIT_KIND);
            }
        }
        function _exitExactBPTInForTokenOut(
            uint256[] memory balances,
            uint256[] memory normalizedWeights,
            uint256 totalSupply,
            bytes memory userData
        ) private view returns (uint256, uint256[] memory) {
            (uint256 bptAmountIn, uint256 tokenIndex) = userData.exactBptInForTokenOut();
            // Note that there is no minimum amountOut parameter: this is handled by `IVault.exitPool`.
            _require(tokenIndex < balances.length, Errors.OUT_OF_BOUNDS);
            uint256 amountOut = WeightedMath._calcTokenOutGivenExactBptIn(
                balances[tokenIndex],
                normalizedWeights[tokenIndex],
                bptAmountIn,
                totalSupply,
                getSwapFeePercentage()
            );
            // This is an exceptional situation in which the fee is charged on a token out instead of a token in.
            // We exit in a single token, so we initialize amountsOut with zeros
            uint256[] memory amountsOut = new uint256[](balances.length);
            // And then assign the result to the selected token
            amountsOut[tokenIndex] = amountOut;
            return (bptAmountIn, amountsOut);
        }
        function _exitExactBPTInForTokensOut(
            uint256[] memory balances,
            uint256 totalSupply,
            bytes memory userData
        ) private pure returns (uint256, uint256[] memory) {
            uint256 bptAmountIn = userData.exactBptInForTokensOut();
            // Note that there is no minimum amountOut parameter: this is handled by `IVault.exitPool`.
            uint256[] memory amountsOut = WeightedMath._calcTokensOutGivenExactBptIn(balances, bptAmountIn, totalSupply);
            return (bptAmountIn, amountsOut);
        }
        function _exitBPTInForExactTokensOut(
            uint256[] memory balances,
            uint256[] memory normalizedWeights,
            uint256[] memory scalingFactors,
            uint256 totalSupply,
            bytes memory userData
        ) private view returns (uint256, uint256[] memory) {
            (uint256[] memory amountsOut, uint256 maxBPTAmountIn) = userData.bptInForExactTokensOut();
            InputHelpers.ensureInputLengthMatch(amountsOut.length, balances.length);
            _upscaleArray(amountsOut, scalingFactors);
            // This is an exceptional situation in which the fee is charged on a token out instead of a token in.
            uint256 bptAmountIn = WeightedMath._calcBptInGivenExactTokensOut(
                balances,
                normalizedWeights,
                amountsOut,
                totalSupply,
                getSwapFeePercentage()
            );
            _require(bptAmountIn <= maxBPTAmountIn, Errors.BPT_IN_MAX_AMOUNT);
            return (bptAmountIn, amountsOut);
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "@balancer-labs/v2-interfaces/contracts/pool-utils/IRateProvider.sol";
    import "@balancer-labs/v2-pool-utils/contracts/protocol-fees/ProtocolFeeCache.sol";
    import "@balancer-labs/v2-pool-utils/contracts/protocol-fees/InvariantGrowthProtocolSwapFees.sol";
    import "./BaseWeightedPool.sol";
    abstract contract WeightedPoolProtocolFees is BaseWeightedPool, ProtocolFeeCache {
        using FixedPoint for uint256;
        using WordCodec for bytes32;
        // Rate providers are used only for computing yield fees; they do not inform swap/join/exit.
        IRateProvider internal immutable _rateProvider0;
        IRateProvider internal immutable _rateProvider1;
        IRateProvider internal immutable _rateProvider2;
        IRateProvider internal immutable _rateProvider3;
        IRateProvider internal immutable _rateProvider4;
        IRateProvider internal immutable _rateProvider5;
        IRateProvider internal immutable _rateProvider6;
        IRateProvider internal immutable _rateProvider7;
        bool internal immutable _exemptFromYieldFees;
        // All-time high value of the weighted product of the pool's token rates. Comparing such weighted products across
        // time provides a measure of the pool's growth resulting from rate changes. The pool also grows due to swap fees,
        // but that growth is captured in the invariant; rate growth is not.
        uint256 private _athRateProduct;
        // This Pool pays protocol fees by measuring the growth of the invariant between joins and exits. Since weights are
        // immutable, the invariant only changes due to accumulated swap fees, which saves gas by freeing the Pool
        // from performing any computation or accounting associated with protocol fees during swaps.
        // This mechanism requires keeping track of the invariant after the last join or exit.
        //
        // The maximum value of the invariant is the maximum allowable balance in the Vault (2**112) multiplied by the
        // largest possible scaling factor (10**18 for a zero decimals token). The largest invariant is then
        // 2**112 * 10**18 ~= 2**172, which means that to save gas we can place this in BasePool's `_miscData`.
        uint256 private constant _LAST_POST_JOINEXIT_INVARIANT_OFFSET = 0;
        uint256 private constant _LAST_POST_JOINEXIT_INVARIANT_BIT_LENGTH = 192;
        constructor(uint256 numTokens, IRateProvider[] memory rateProviders) {
            _require(numTokens <= 8, Errors.MAX_TOKENS);
            InputHelpers.ensureInputLengthMatch(numTokens, rateProviders.length);
            _exemptFromYieldFees = _getYieldFeeExemption(rateProviders);
            _rateProvider0 = rateProviders[0];
            _rateProvider1 = rateProviders[1];
            _rateProvider2 = numTokens > 2 ? rateProviders[2] : IRateProvider(0);
            _rateProvider3 = numTokens > 3 ? rateProviders[3] : IRateProvider(0);
            _rateProvider4 = numTokens > 4 ? rateProviders[4] : IRateProvider(0);
            _rateProvider5 = numTokens > 5 ? rateProviders[5] : IRateProvider(0);
            _rateProvider6 = numTokens > 6 ? rateProviders[6] : IRateProvider(0);
            _rateProvider7 = numTokens > 7 ? rateProviders[7] : IRateProvider(0);
        }
        function _getYieldFeeExemption(IRateProvider[] memory rateProviders) internal pure returns (bool) {
            // If we know that no rate providers are set then we can skip yield fees logic.
            // If any tokens have rate providers, then set `_exemptFromYieldFees` to false, otherwise leave it true.
            for (uint256 i = 0; i < rateProviders.length; i++) {
                if (rateProviders[i] != IRateProvider(0)) {
                    return false;
                }
            }
            return true;
        }
        /**
         * @dev Returns whether the pool is exempt from protocol fees on yield.
         */
        function _isExemptFromYieldProtocolFees() internal view returns (bool) {
            return _exemptFromYieldFees;
        }
        /**
         * @notice Returns the value of the invariant after the last join or exit operation.
         */
        function getLastPostJoinExitInvariant() public view returns (uint256) {
            return
                _getMiscData().decodeUint(_LAST_POST_JOINEXIT_INVARIANT_OFFSET, _LAST_POST_JOINEXIT_INVARIANT_BIT_LENGTH);
        }
        /**
         * @notice Returns the all time high value for the weighted product of the Pool's tokens' rates.
         * @dev Yield protocol fees are only charged when this value is exceeded.
         */
        function getATHRateProduct() public view returns (uint256) {
            return _athRateProduct;
        }
        /**
         * @dev Returns the rate providers configured for each token (in the same order as registered).
         */
        function getRateProviders() external view returns (IRateProvider[] memory) {
            uint256 totalTokens = _getTotalTokens();
            IRateProvider[] memory providers = new IRateProvider[](totalTokens);
            // prettier-ignore
            {
                providers[0] = _rateProvider0;
                providers[1] = _rateProvider1;
                if (totalTokens > 2) { providers[2] = _rateProvider2; } else { return providers; }
                if (totalTokens > 3) { providers[3] = _rateProvider3; } else { return providers; }
                if (totalTokens > 4) { providers[4] = _rateProvider4; } else { return providers; }
                if (totalTokens > 5) { providers[5] = _rateProvider5; } else { return providers; }
                if (totalTokens > 6) { providers[6] = _rateProvider6; } else { return providers; }
                if (totalTokens > 7) { providers[7] = _rateProvider7; } else { return providers; }
            }
            return providers;
        }
        // Protocol Fees
        /**
         * @dev Returns the percentage of the Pool's supply which corresponds to protocol fees on swaps accrued by the Pool.
         * @param preJoinExitInvariant - The Pool's invariant prior to the join/exit *before* minting protocol fees.
         * @param protocolSwapFeePercentage - The percentage of swap fees which are paid to the protocol.
         * @return swapProtocolFeesPercentage - The percentage of the Pool which corresponds to protocol fees on swaps.
         */
        function _getSwapProtocolFeesPoolPercentage(uint256 preJoinExitInvariant, uint256 protocolSwapFeePercentage)
            internal
            view
            returns (uint256)
        {
            // Before joins and exits, we measure the growth of the invariant compared to the invariant after the last join
            // or exit, which will have been caused by swap fees, and use it to mint BPT as protocol fees. This dilutes all
            // LPs, which means that new LPs will join the pool debt-free, and exiting LPs will pay any amounts due
            // before leaving.
            return
                InvariantGrowthProtocolSwapFees.getProtocolOwnershipPercentage(
                    preJoinExitInvariant.divDown(getLastPostJoinExitInvariant()),
                    FixedPoint.ONE, // Supply has not changed so supplyGrowthRatio = 1
                    protocolSwapFeePercentage
                );
        }
        /**
         * @dev Returns the percentage of the Pool's supply which corresponds to protocol fees on yield accrued by the Pool.
         * @param normalizedWeights - The Pool's normalized token weights.
         * @return yieldProtocolFeesPercentage - The percentage of the Pool which corresponds to protocol fees on yield.
         * @return athRateProduct - The new all-time-high rate product if it has increased, otherwise zero.
         */
        function _getYieldProtocolFeesPoolPercentage(uint256[] memory normalizedWeights)
            internal
            view
            returns (uint256, uint256)
        {
            if (_isExemptFromYieldProtocolFees()) return (0, 0);
            // Yield manifests in the Pool by individual tokens becoming more valuable, we convert this into comparable
            // units by applying a rate to get the equivalent balance of non-yield-bearing tokens
            //
            // non-yield-bearing balance = rate * yield-bearing balance
            //                       x'i = ri * xi
            //
            // To measure the amount of fees to pay due to yield, we take advantage of the fact that scaling the
            // Pool's balances results in a scaling factor being applied to the original invariant.
            //
            // I(r1 * x1, r2 * x2) = (r1 * x1)^w1 * (r2 * x2)^w2
            //                     = (r1)^w1 * (r2)^w2 * (x1)^w1 * (x2)^w2
            //                     = I(r1, r2) * I(x1, x2)
            //
            // We then only need to measure the growth of this scaling factor to measure how the value of the BPT token
            // increases due to yield; we can ignore the invariant calculated from the Pool's balances as these cancel.
            // We then have the result:
            //
            // invariantGrowthRatio = I(r1_new, r2_new) / I(r1_old, r2_old) = rateProduct / athRateProduct
            uint256 athRateProduct = _athRateProduct;
            uint256 rateProduct = _getRateProduct(normalizedWeights);
            // Only charge yield fees if we've exceeded the all time high of Pool value generated through yield.
            // i.e. if the Pool makes a loss through the yield strategies then it shouldn't charge fees until it's
            // been recovered.
            if (rateProduct <= athRateProduct) return (0, 0);
            return (
                InvariantGrowthProtocolSwapFees.getProtocolOwnershipPercentage(
                    rateProduct.divDown(athRateProduct),
                    FixedPoint.ONE, // Supply has not changed so supplyGrowthRatio = 1
                    getProtocolFeePercentageCache(ProtocolFeeType.YIELD)
                ),
                rateProduct
            );
        }
        function _updateATHRateProduct(uint256 rateProduct) internal {
            _athRateProduct = rateProduct;
        }
        /**
         * @dev Returns the amount of BPT to be minted as protocol fees prior to processing a join/exit.
         * Note that this isn't a view function. This function automatically updates `_athRateProduct`  to ensure that
         * proper accounting is performed to prevent charging duplicate protocol fees.
         * @param preJoinExitInvariant - The Pool's invariant prior to the join/exit.
         * @param normalizedWeights - The Pool's normalized token weights.
         * @param preJoinExitSupply - The Pool's total supply prior to the join/exit *before* minting protocol fees.
         * @return protocolFeesToBeMinted -  The amount of BPT to be minted as protocol fees.
         * @return athRateProduct - The new all-time-high rate product if it has increased, otherwise zero.
         */
        function _getPreJoinExitProtocolFees(
            uint256 preJoinExitInvariant,
            uint256[] memory normalizedWeights,
            uint256 preJoinExitSupply
        ) internal view returns (uint256, uint256) {
            uint256 protocolSwapFeesPoolPercentage = _getSwapProtocolFeesPoolPercentage(
                preJoinExitInvariant,
                getProtocolFeePercentageCache(ProtocolFeeType.SWAP)
            );
            (uint256 protocolYieldFeesPoolPercentage, uint256 athRateProduct) = _getYieldProtocolFeesPoolPercentage(
                normalizedWeights
            );
            return (
                ProtocolFees.bptForPoolOwnershipPercentage(
                    preJoinExitSupply,
                    protocolSwapFeesPoolPercentage + protocolYieldFeesPoolPercentage
                ),
                athRateProduct
            );
        }
        /**
         * @dev Returns the amount of BPT to be minted to pay protocol fees on swap fees accrued during a join/exit.
         * Note that this isn't a view function. This function automatically updates `_lastPostJoinExitInvariant` to
         * ensure that proper accounting is performed to prevent charging duplicate protocol fees.
         * @param preJoinExitInvariant - The Pool's invariant prior to the join/exit.
         * @param preBalances - The Pool's balances prior to the join/exit.
         * @param balanceDeltas - The changes to the Pool's balances due to the join/exit.
         * @param normalizedWeights - The Pool's normalized token weights.
         * @param preJoinExitSupply - The Pool's total supply prior to the join/exit *after* minting protocol fees.
         * @param postJoinExitSupply - The Pool's total supply after the join/exit.
         */
        function _getPostJoinExitProtocolFees(
            uint256 preJoinExitInvariant,
            uint256[] memory preBalances,
            uint256[] memory balanceDeltas,
            uint256[] memory normalizedWeights,
            uint256 preJoinExitSupply,
            uint256 postJoinExitSupply
        ) internal returns (uint256) {
            bool isJoin = postJoinExitSupply >= preJoinExitSupply;
            // Compute the post balances by adding or removing the deltas.
            for (uint256 i = 0; i < preBalances.length; ++i) {
                preBalances[i] = isJoin
                    ? SafeMath.add(preBalances[i], balanceDeltas[i])
                    : SafeMath.sub(preBalances[i], balanceDeltas[i]);
            }
            // preBalances have now been mutated to reflect the postJoinExit balances.
            uint256 postJoinExitInvariant = WeightedMath._calculateInvariant(normalizedWeights, preBalances);
            uint256 protocolSwapFeePercentage = getProtocolFeePercentageCache(ProtocolFeeType.SWAP);
            _updatePostJoinExit(postJoinExitInvariant);
            // We return immediately if the fee percentage is zero to avoid unnecessary computation.
            if (protocolSwapFeePercentage == 0) return 0;
            uint256 protocolFeeAmount = InvariantGrowthProtocolSwapFees.calcDueProtocolFees(
                postJoinExitInvariant.divDown(preJoinExitInvariant),
                preJoinExitSupply,
                postJoinExitSupply,
                protocolSwapFeePercentage
            );
            return protocolFeeAmount;
        }
        function _updatePostJoinExit(uint256 postJoinExitInvariant) internal virtual override {
            // After all joins and exits we store the post join/exit invariant in order to compute growth due to swap fees
            // in the next one.
            _setMiscData(
                _getMiscData().insertUint(
                    postJoinExitInvariant,
                    _LAST_POST_JOINEXIT_INVARIANT_OFFSET,
                    _LAST_POST_JOINEXIT_INVARIANT_BIT_LENGTH
                )
            );
        }
        // Helper functions
        /**
         * @notice Returns the contribution to the total rate product from a token with the given weight and rate provider.
         */
        function _getRateFactor(uint256 normalizedWeight, IRateProvider provider) internal view returns (uint256) {
            return provider == IRateProvider(0) ? FixedPoint.ONE : provider.getRate().powDown(normalizedWeight);
        }
        /**
         * @dev Returns the weighted product of all the token rates.
         */
        function _getRateProduct(uint256[] memory normalizedWeights) internal view returns (uint256) {
            uint256 totalTokens = normalizedWeights.length;
            uint256 rateProduct = FixedPoint.mulDown(
                _getRateFactor(normalizedWeights[0], _rateProvider0),
                _getRateFactor(normalizedWeights[1], _rateProvider1)
            );
            if (totalTokens > 2) {
                rateProduct = rateProduct.mulDown(_getRateFactor(normalizedWeights[2], _rateProvider2));
            } else {
                return rateProduct;
            }
            if (totalTokens > 3) {
                rateProduct = rateProduct.mulDown(_getRateFactor(normalizedWeights[3], _rateProvider3));
            } else {
                return rateProduct;
            }
            if (totalTokens > 4) {
                rateProduct = rateProduct.mulDown(_getRateFactor(normalizedWeights[4], _rateProvider4));
            } else {
                return rateProduct;
            }
            if (totalTokens > 5) {
                rateProduct = rateProduct.mulDown(_getRateFactor(normalizedWeights[5], _rateProvider5));
            } else {
                return rateProduct;
            }
            if (totalTokens > 6) {
                rateProduct = rateProduct.mulDown(_getRateFactor(normalizedWeights[6], _rateProvider6));
            } else {
                return rateProduct;
            }
            if (totalTokens > 7) {
                rateProduct = rateProduct.mulDown(_getRateFactor(normalizedWeights[7], _rateProvider7));
            }
            return rateProduct;
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "../solidity-utils/openzeppelin/IERC20.sol";
    library WeightedPoolUserData {
        // In order to preserve backwards compatibility, make sure new join and exit kinds are added at the end of the enum.
        enum JoinKind {
            INIT,
            EXACT_TOKENS_IN_FOR_BPT_OUT,
            TOKEN_IN_FOR_EXACT_BPT_OUT,
            ALL_TOKENS_IN_FOR_EXACT_BPT_OUT,
            ADD_TOKEN // for Managed Pool
        }
        enum ExitKind {
            EXACT_BPT_IN_FOR_ONE_TOKEN_OUT,
            EXACT_BPT_IN_FOR_TOKENS_OUT,
            BPT_IN_FOR_EXACT_TOKENS_OUT,
            REMOVE_TOKEN // for ManagedPool
        }
        function joinKind(bytes memory self) internal pure returns (JoinKind) {
            return abi.decode(self, (JoinKind));
        }
        function exitKind(bytes memory self) internal pure returns (ExitKind) {
            return abi.decode(self, (ExitKind));
        }
        // Joins
        function initialAmountsIn(bytes memory self) internal pure returns (uint256[] memory amountsIn) {
            (, amountsIn) = abi.decode(self, (JoinKind, uint256[]));
        }
        function exactTokensInForBptOut(bytes memory self)
            internal
            pure
            returns (uint256[] memory amountsIn, uint256 minBPTAmountOut)
        {
            (, amountsIn, minBPTAmountOut) = abi.decode(self, (JoinKind, uint256[], uint256));
        }
        function tokenInForExactBptOut(bytes memory self) internal pure returns (uint256 bptAmountOut, uint256 tokenIndex) {
            (, bptAmountOut, tokenIndex) = abi.decode(self, (JoinKind, uint256, uint256));
        }
        function allTokensInForExactBptOut(bytes memory self) internal pure returns (uint256 bptAmountOut) {
            (, bptAmountOut) = abi.decode(self, (JoinKind, uint256));
        }
        function addToken(bytes memory self) internal pure returns (uint256 amountIn) {
            (, amountIn) = abi.decode(self, (JoinKind, uint256));
        }
        // Exits
        function exactBptInForTokenOut(bytes memory self) internal pure returns (uint256 bptAmountIn, uint256 tokenIndex) {
            (, bptAmountIn, tokenIndex) = abi.decode(self, (ExitKind, uint256, uint256));
        }
        function exactBptInForTokensOut(bytes memory self) internal pure returns (uint256 bptAmountIn) {
            (, bptAmountIn) = abi.decode(self, (ExitKind, uint256));
        }
        function bptInForExactTokensOut(bytes memory self)
            internal
            pure
            returns (uint256[] memory amountsOut, uint256 maxBPTAmountIn)
        {
            (, amountsOut, maxBPTAmountIn) = abi.decode(self, (ExitKind, uint256[], uint256));
        }
        // Managed Pool
        function removeToken(bytes memory self) internal pure returns (uint256 tokenIndex) {
            (, tokenIndex) = abi.decode(self, (ExitKind, uint256));
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    import "./LogExpMath.sol";
    /* solhint-disable private-vars-leading-underscore */
    library FixedPoint {
        uint256 internal constant ONE = 1e18; // 18 decimal places
        uint256 internal constant TWO = 2 * ONE;
        uint256 internal constant FOUR = 4 * ONE;
        uint256 internal constant MAX_POW_RELATIVE_ERROR = 10000; // 10^(-14)
        // Minimum base for the power function when the exponent is 'free' (larger than ONE).
        uint256 internal constant MIN_POW_BASE_FREE_EXPONENT = 0.7e18;
        function add(uint256 a, uint256 b) internal pure returns (uint256) {
            // Fixed Point addition is the same as regular checked addition
            uint256 c = a + b;
            _require(c >= a, Errors.ADD_OVERFLOW);
            return c;
        }
        function sub(uint256 a, uint256 b) internal pure returns (uint256) {
            // Fixed Point addition is the same as regular checked addition
            _require(b <= a, Errors.SUB_OVERFLOW);
            uint256 c = a - b;
            return c;
        }
        function mulDown(uint256 a, uint256 b) internal pure returns (uint256) {
            uint256 product = a * b;
            _require(a == 0 || product / a == b, Errors.MUL_OVERFLOW);
            return product / ONE;
        }
        function mulUp(uint256 a, uint256 b) internal pure returns (uint256) {
            uint256 product = a * b;
            _require(a == 0 || product / a == b, Errors.MUL_OVERFLOW);
            if (product == 0) {
                return 0;
            } else {
                // The traditional divUp formula is:
                // divUp(x, y) := (x + y - 1) / y
                // To avoid intermediate overflow in the addition, we distribute the division and get:
                // divUp(x, y) := (x - 1) / y + 1
                // Note that this requires x != 0, which we already tested for.
                return ((product - 1) / ONE) + 1;
            }
        }
        function divDown(uint256 a, uint256 b) internal pure returns (uint256) {
            _require(b != 0, Errors.ZERO_DIVISION);
            if (a == 0) {
                return 0;
            } else {
                uint256 aInflated = a * ONE;
                _require(aInflated / a == ONE, Errors.DIV_INTERNAL); // mul overflow
                return aInflated / b;
            }
        }
        function divUp(uint256 a, uint256 b) internal pure returns (uint256) {
            _require(b != 0, Errors.ZERO_DIVISION);
            if (a == 0) {
                return 0;
            } else {
                uint256 aInflated = a * ONE;
                _require(aInflated / a == ONE, Errors.DIV_INTERNAL); // mul overflow
                // The traditional divUp formula is:
                // divUp(x, y) := (x + y - 1) / y
                // To avoid intermediate overflow in the addition, we distribute the division and get:
                // divUp(x, y) := (x - 1) / y + 1
                // Note that this requires x != 0, which we already tested for.
                return ((aInflated - 1) / b) + 1;
            }
        }
        /**
         * @dev Returns x^y, assuming both are fixed point numbers, rounding down. The result is guaranteed to not be above
         * the true value (that is, the error function expected - actual is always positive).
         */
        function powDown(uint256 x, uint256 y) internal pure returns (uint256) {
            // Optimize for when y equals 1.0, 2.0 or 4.0, as those are very simple to implement and occur often in 50/50
            // and 80/20 Weighted Pools
            if (y == ONE) {
                return x;
            } else if (y == TWO) {
                return mulDown(x, x);
            } else if (y == FOUR) {
                uint256 square = mulDown(x, x);
                return mulDown(square, square);
            } else {
                uint256 raw = LogExpMath.pow(x, y);
                uint256 maxError = add(mulUp(raw, MAX_POW_RELATIVE_ERROR), 1);
                if (raw < maxError) {
                    return 0;
                } else {
                    return sub(raw, maxError);
                }
            }
        }
        /**
         * @dev Returns x^y, assuming both are fixed point numbers, rounding up. The result is guaranteed to not be below
         * the true value (that is, the error function expected - actual is always negative).
         */
        function powUp(uint256 x, uint256 y) internal pure returns (uint256) {
            // Optimize for when y equals 1.0, 2.0 or 4.0, as those are very simple to implement and occur often in 50/50
            // and 80/20 Weighted Pools
            if (y == ONE) {
                return x;
            } else if (y == TWO) {
                return mulUp(x, x);
            } else if (y == FOUR) {
                uint256 square = mulUp(x, x);
                return mulUp(square, square);
            } else {
                uint256 raw = LogExpMath.pow(x, y);
                uint256 maxError = add(mulUp(raw, MAX_POW_RELATIVE_ERROR), 1);
                return add(raw, maxError);
            }
        }
        /**
         * @dev Returns the complement of a value (1 - x), capped to 0 if x is larger than 1.
         *
         * Useful when computing the complement for values with some level of relative error, as it strips this error and
         * prevents intermediate negative values.
         */
        function complement(uint256 x) internal pure returns (uint256) {
            return (x < ONE) ? (ONE - x) : 0;
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/openzeppelin/IERC20.sol";
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    library InputHelpers {
        function ensureInputLengthMatch(uint256 a, uint256 b) internal pure {
            _require(a == b, Errors.INPUT_LENGTH_MISMATCH);
        }
        function ensureInputLengthMatch(
            uint256 a,
            uint256 b,
            uint256 c
        ) internal pure {
            _require(a == b && b == c, Errors.INPUT_LENGTH_MISMATCH);
        }
        function ensureArrayIsSorted(IERC20[] memory array) internal pure {
            address[] memory addressArray;
            // solhint-disable-next-line no-inline-assembly
            assembly {
                addressArray := array
            }
            ensureArrayIsSorted(addressArray);
        }
        function ensureArrayIsSorted(address[] memory array) internal pure {
            if (array.length < 2) {
                return;
            }
            address previous = array[0];
            for (uint256 i = 1; i < array.length; ++i) {
                address current = array[i];
                _require(previous < current, Errors.UNSORTED_ARRAY);
                previous = current;
            }
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "@balancer-labs/v2-interfaces/contracts/vault/IMinimalSwapInfoPool.sol";
    import "./BasePool.sol";
    /**
     * @dev Extension of `BasePool`, adding a handler for `IMinimalSwapInfoPool.onSwap`.
     *
     * Derived contracts must call `BasePool`'s constructor, and implement `_onSwapGivenIn` and `_onSwapGivenOut` along with
     * `BasePool`'s virtual functions. Inheriting from this contract lets derived contracts choose the Two Token or Minimal
     * Swap Info specialization settings.
     */
    abstract contract BaseMinimalSwapInfoPool is IMinimalSwapInfoPool, BasePool {
        // Swap Hooks
        function onSwap(
            SwapRequest memory request,
            uint256 balanceTokenIn,
            uint256 balanceTokenOut
        ) public override onlyVault(request.poolId) returns (uint256) {
            _beforeSwapJoinExit();
            uint256 scalingFactorTokenIn = _scalingFactor(request.tokenIn);
            uint256 scalingFactorTokenOut = _scalingFactor(request.tokenOut);
            balanceTokenIn = _upscale(balanceTokenIn, scalingFactorTokenIn);
            balanceTokenOut = _upscale(balanceTokenOut, scalingFactorTokenOut);
            if (request.kind == IVault.SwapKind.GIVEN_IN) {
                // Fees are subtracted before scaling, to reduce the complexity of the rounding direction analysis.
                request.amount = _subtractSwapFeeAmount(request.amount);
                // All token amounts are upscaled.
                request.amount = _upscale(request.amount, scalingFactorTokenIn);
                uint256 amountOut = _onSwapGivenIn(request, balanceTokenIn, balanceTokenOut);
                // amountOut tokens are exiting the Pool, so we round down.
                return _downscaleDown(amountOut, scalingFactorTokenOut);
            } else {
                // All token amounts are upscaled.
                request.amount = _upscale(request.amount, scalingFactorTokenOut);
                uint256 amountIn = _onSwapGivenOut(request, balanceTokenIn, balanceTokenOut);
                // amountIn tokens are entering the Pool, so we round up.
                amountIn = _downscaleUp(amountIn, scalingFactorTokenIn);
                // Fees are added after scaling happens, to reduce the complexity of the rounding direction analysis.
                return _addSwapFeeAmount(amountIn);
            }
        }
        /*
         * @dev Called when a swap with the Pool occurs, where the amount of tokens entering the Pool is known.
         *
         * Returns the amount of tokens that will be taken from the Pool in return.
         *
         * All amounts inside `swapRequest`, `balanceTokenIn`, and `balanceTokenOut` are upscaled. The swap fee has already
         * been deducted from `swapRequest.amount`.
         *
         * The return value is also considered upscaled, and will be downscaled (rounding down) before returning it to the
         * Vault.
         */
        function _onSwapGivenIn(
            SwapRequest memory swapRequest,
            uint256 balanceTokenIn,
            uint256 balanceTokenOut
        ) internal virtual returns (uint256);
        /*
         * @dev Called when a swap with the Pool occurs, where the amount of tokens exiting the Pool is known.
         *
         * Returns the amount of tokens that will be granted to the Pool in return.
         *
         * All amounts inside `swapRequest`, `balanceTokenIn`, and `balanceTokenOut` are upscaled.
         *
         * The return value is also considered upscaled, and will be downscaled (rounding up) before applying the swap fee
         * and returning it to the Vault.
         */
        function _onSwapGivenOut(
            SwapRequest memory swapRequest,
            uint256 balanceTokenIn,
            uint256 balanceTokenOut
        ) internal virtual returns (uint256);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-solidity-utils/contracts/helpers/InputHelpers.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/math/FixedPoint.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/math/Math.sol";
    // These functions start with an underscore, as if they were part of a contract and not a library. At some point this
    // should be fixed.
    // solhint-disable private-vars-leading-underscore
    library WeightedMath {
        using FixedPoint for uint256;
        // A minimum normalized weight imposes a maximum weight ratio. We need this due to limitations in the
        // implementation of the power function, as these ratios are often exponents.
        uint256 internal constant _MIN_WEIGHT = 0.01e18;
        // Having a minimum normalized weight imposes a limit on the maximum number of tokens;
        // i.e., the largest possible pool is one where all tokens have exactly the minimum weight.
        uint256 internal constant _MAX_WEIGHTED_TOKENS = 100;
        // Pool limits that arise from limitations in the fixed point power function (and the imposed 1:100 maximum weight
        // ratio).
        // Swap limits: amounts swapped may not be larger than this percentage of total balance.
        uint256 internal constant _MAX_IN_RATIO = 0.3e18;
        uint256 internal constant _MAX_OUT_RATIO = 0.3e18;
        // Invariant growth limit: non-proportional joins cannot cause the invariant to increase by more than this ratio.
        uint256 internal constant _MAX_INVARIANT_RATIO = 3e18;
        // Invariant shrink limit: non-proportional exits cannot cause the invariant to decrease by less than this ratio.
        uint256 internal constant _MIN_INVARIANT_RATIO = 0.7e18;
        // About swap fees on joins and exits:
        // Any join or exit that is not perfectly balanced (e.g. all single token joins or exits) is mathematically
        // equivalent to a perfectly balanced join or exit followed by a series of swaps. Since these swaps would charge
        // swap fees, it follows that (some) joins and exits should as well.
        // On these operations, we split the token amounts in 'taxable' and 'non-taxable' portions, where the 'taxable' part
        // is the one to which swap fees are applied.
        // Invariant is used to collect protocol swap fees by comparing its value between two times.
        // So we can round always to the same direction. It is also used to initiate the BPT amount
        // and, because there is a minimum BPT, we round down the invariant.
        function _calculateInvariant(uint256[] memory normalizedWeights, uint256[] memory balances)
            internal
            pure
            returns (uint256 invariant)
        {
            /**********************************************************************************************
            // invariant               _____                                                             //
            // wi = weight index i      | |      wi                                                      //
            // bi = balance index i     | |  bi ^   = i                                                  //
            // i = invariant                                                                             //
            **********************************************************************************************/
            invariant = FixedPoint.ONE;
            for (uint256 i = 0; i < normalizedWeights.length; i++) {
                invariant = invariant.mulDown(balances[i].powDown(normalizedWeights[i]));
            }
            _require(invariant > 0, Errors.ZERO_INVARIANT);
        }
        // Computes how many tokens can be taken out of a pool if `amountIn` are sent, given the
        // current balances and weights.
        function _calcOutGivenIn(
            uint256 balanceIn,
            uint256 weightIn,
            uint256 balanceOut,
            uint256 weightOut,
            uint256 amountIn
        ) internal pure returns (uint256) {
            /**********************************************************************************************
            // outGivenIn                                                                                //
            // aO = amountOut                                                                            //
            // bO = balanceOut                                                                           //
            // bI = balanceIn              /      /            bI             \\    (wI / wO) \\           //
            // aI = amountIn    aO = bO * |  1 - | --------------------------  | ^            |          //
            // wI = weightIn               \\      \\       ( bI + aI )         /              /           //
            // wO = weightOut                                                                            //
            **********************************************************************************************/
            // Amount out, so we round down overall.
            // The multiplication rounds down, and the subtrahend (power) rounds up (so the base rounds up too).
            // Because bI / (bI + aI) <= 1, the exponent rounds down.
            // Cannot exceed maximum in ratio
            _require(amountIn <= balanceIn.mulDown(_MAX_IN_RATIO), Errors.MAX_IN_RATIO);
            uint256 denominator = balanceIn.add(amountIn);
            uint256 base = balanceIn.divUp(denominator);
            uint256 exponent = weightIn.divDown(weightOut);
            uint256 power = base.powUp(exponent);
            return balanceOut.mulDown(power.complement());
        }
        // Computes how many tokens must be sent to a pool in order to take `amountOut`, given the
        // current balances and weights.
        function _calcInGivenOut(
            uint256 balanceIn,
            uint256 weightIn,
            uint256 balanceOut,
            uint256 weightOut,
            uint256 amountOut
        ) internal pure returns (uint256) {
            /**********************************************************************************************
            // inGivenOut                                                                                //
            // aO = amountOut                                                                            //
            // bO = balanceOut                                                                           //
            // bI = balanceIn              /  /            bO             \\    (wO / wI)      \\          //
            // aI = amountIn    aI = bI * |  | --------------------------  | ^            - 1  |         //
            // wI = weightIn               \\  \\       ( bO - aO )         /                   /          //
            // wO = weightOut                                                                            //
            **********************************************************************************************/
            // Amount in, so we round up overall.
            // The multiplication rounds up, and the power rounds up (so the base rounds up too).
            // Because b0 / (b0 - a0) >= 1, the exponent rounds up.
            // Cannot exceed maximum out ratio
            _require(amountOut <= balanceOut.mulDown(_MAX_OUT_RATIO), Errors.MAX_OUT_RATIO);
            uint256 base = balanceOut.divUp(balanceOut.sub(amountOut));
            uint256 exponent = weightOut.divUp(weightIn);
            uint256 power = base.powUp(exponent);
            // Because the base is larger than one (and the power rounds up), the power should always be larger than one, so
            // the following subtraction should never revert.
            uint256 ratio = power.sub(FixedPoint.ONE);
            return balanceIn.mulUp(ratio);
        }
        function _calcBptOutGivenExactTokensIn(
            uint256[] memory balances,
            uint256[] memory normalizedWeights,
            uint256[] memory amountsIn,
            uint256 bptTotalSupply,
            uint256 swapFeePercentage
        ) internal pure returns (uint256) {
            // BPT out, so we round down overall.
            uint256[] memory balanceRatiosWithFee = new uint256[](amountsIn.length);
            uint256 invariantRatioWithFees = 0;
            for (uint256 i = 0; i < balances.length; i++) {
                balanceRatiosWithFee[i] = balances[i].add(amountsIn[i]).divDown(balances[i]);
                invariantRatioWithFees = invariantRatioWithFees.add(balanceRatiosWithFee[i].mulDown(normalizedWeights[i]));
            }
            uint256 invariantRatio = _computeJoinExactTokensInInvariantRatio(
                balances,
                normalizedWeights,
                amountsIn,
                balanceRatiosWithFee,
                invariantRatioWithFees,
                swapFeePercentage
            );
            uint256 bptOut = (invariantRatio > FixedPoint.ONE)
                ? bptTotalSupply.mulDown(invariantRatio.sub(FixedPoint.ONE))
                : 0;
            return bptOut;
        }
        /**
         * @dev Intermediate function to avoid stack-too-deep errors.
         */
        function _computeJoinExactTokensInInvariantRatio(
            uint256[] memory balances,
            uint256[] memory normalizedWeights,
            uint256[] memory amountsIn,
            uint256[] memory balanceRatiosWithFee,
            uint256 invariantRatioWithFees,
            uint256 swapFeePercentage
        ) private pure returns (uint256 invariantRatio) {
            // Swap fees are charged on all tokens that are being added in a larger proportion than the overall invariant
            // increase.
            invariantRatio = FixedPoint.ONE;
            for (uint256 i = 0; i < balances.length; i++) {
                uint256 amountInWithoutFee;
                if (balanceRatiosWithFee[i] > invariantRatioWithFees) {
                    uint256 nonTaxableAmount = balances[i].mulDown(invariantRatioWithFees.sub(FixedPoint.ONE));
                    uint256 taxableAmount = amountsIn[i].sub(nonTaxableAmount);
                    uint256 swapFee = taxableAmount.mulUp(swapFeePercentage);
                    amountInWithoutFee = nonTaxableAmount.add(taxableAmount.sub(swapFee));
                } else {
                    amountInWithoutFee = amountsIn[i];
                }
                uint256 balanceRatio = balances[i].add(amountInWithoutFee).divDown(balances[i]);
                invariantRatio = invariantRatio.mulDown(balanceRatio.powDown(normalizedWeights[i]));
            }
        }
        function _calcTokenInGivenExactBptOut(
            uint256 balance,
            uint256 normalizedWeight,
            uint256 bptAmountOut,
            uint256 bptTotalSupply,
            uint256 swapFeePercentage
        ) internal pure returns (uint256) {
            /******************************************************************************************
            // tokenInForExactBPTOut                                                                 //
            // a = amountIn                                                                          //
            // b = balance                      /  /    totalBPT + bptOut      \\    (1 / w)       \\  //
            // bptOut = bptAmountOut   a = b * |  | --------------------------  | ^          - 1  |  //
            // bpt = totalBPT                   \\  \\       totalBPT            /                  /  //
            // w = weight                                                                            //
            ******************************************************************************************/
            // Token in, so we round up overall.
            // Calculate the factor by which the invariant will increase after minting BPTAmountOut
            uint256 invariantRatio = bptTotalSupply.add(bptAmountOut).divUp(bptTotalSupply);
            _require(invariantRatio <= _MAX_INVARIANT_RATIO, Errors.MAX_OUT_BPT_FOR_TOKEN_IN);
            // Calculate by how much the token balance has to increase to match the invariantRatio
            uint256 balanceRatio = invariantRatio.powUp(FixedPoint.ONE.divUp(normalizedWeight));
            uint256 amountInWithoutFee = balance.mulUp(balanceRatio.sub(FixedPoint.ONE));
            // We can now compute how much extra balance is being deposited and used in virtual swaps, and charge swap fees
            // accordingly.
            uint256 taxableAmount = amountInWithoutFee.mulUp(normalizedWeight.complement());
            uint256 nonTaxableAmount = amountInWithoutFee.sub(taxableAmount);
            uint256 taxableAmountPlusFees = taxableAmount.divUp(swapFeePercentage.complement());
            return nonTaxableAmount.add(taxableAmountPlusFees);
        }
        function _calcAllTokensInGivenExactBptOut(
            uint256[] memory balances,
            uint256 bptAmountOut,
            uint256 totalBPT
        ) internal pure returns (uint256[] memory) {
            /************************************************************************************
            // tokensInForExactBptOut                                                          //
            // (per token)                                                                     //
            // aI = amountIn                   /   bptOut   \\                                  //
            // b = balance           aI = b * | ------------ |                                 //
            // bptOut = bptAmountOut           \\  totalBPT  /                                  //
            // bpt = totalBPT                                                                  //
            ************************************************************************************/
            // Tokens in, so we round up overall.
            uint256 bptRatio = bptAmountOut.divUp(totalBPT);
            uint256[] memory amountsIn = new uint256[](balances.length);
            for (uint256 i = 0; i < balances.length; i++) {
                amountsIn[i] = balances[i].mulUp(bptRatio);
            }
            return amountsIn;
        }
        function _calcBptInGivenExactTokensOut(
            uint256[] memory balances,
            uint256[] memory normalizedWeights,
            uint256[] memory amountsOut,
            uint256 bptTotalSupply,
            uint256 swapFeePercentage
        ) internal pure returns (uint256) {
            // BPT in, so we round up overall.
            uint256[] memory balanceRatiosWithoutFee = new uint256[](amountsOut.length);
            uint256 invariantRatioWithoutFees = 0;
            for (uint256 i = 0; i < balances.length; i++) {
                balanceRatiosWithoutFee[i] = balances[i].sub(amountsOut[i]).divUp(balances[i]);
                invariantRatioWithoutFees = invariantRatioWithoutFees.add(
                    balanceRatiosWithoutFee[i].mulUp(normalizedWeights[i])
                );
            }
            uint256 invariantRatio = _computeExitExactTokensOutInvariantRatio(
                balances,
                normalizedWeights,
                amountsOut,
                balanceRatiosWithoutFee,
                invariantRatioWithoutFees,
                swapFeePercentage
            );
            return bptTotalSupply.mulUp(invariantRatio.complement());
        }
        /**
         * @dev Intermediate function to avoid stack-too-deep errors.
         */
        function _computeExitExactTokensOutInvariantRatio(
            uint256[] memory balances,
            uint256[] memory normalizedWeights,
            uint256[] memory amountsOut,
            uint256[] memory balanceRatiosWithoutFee,
            uint256 invariantRatioWithoutFees,
            uint256 swapFeePercentage
        ) private pure returns (uint256 invariantRatio) {
            invariantRatio = FixedPoint.ONE;
            for (uint256 i = 0; i < balances.length; i++) {
                // Swap fees are typically charged on 'token in', but there is no 'token in' here, so we apply it to
                // 'token out'. This results in slightly larger price impact.
                uint256 amountOutWithFee;
                if (invariantRatioWithoutFees > balanceRatiosWithoutFee[i]) {
                    uint256 nonTaxableAmount = balances[i].mulDown(invariantRatioWithoutFees.complement());
                    uint256 taxableAmount = amountsOut[i].sub(nonTaxableAmount);
                    uint256 taxableAmountPlusFees = taxableAmount.divUp(swapFeePercentage.complement());
                    amountOutWithFee = nonTaxableAmount.add(taxableAmountPlusFees);
                } else {
                    amountOutWithFee = amountsOut[i];
                }
                uint256 balanceRatio = balances[i].sub(amountOutWithFee).divDown(balances[i]);
                invariantRatio = invariantRatio.mulDown(balanceRatio.powDown(normalizedWeights[i]));
            }
        }
        function _calcTokenOutGivenExactBptIn(
            uint256 balance,
            uint256 normalizedWeight,
            uint256 bptAmountIn,
            uint256 bptTotalSupply,
            uint256 swapFeePercentage
        ) internal pure returns (uint256) {
            /*****************************************************************************************
            // exactBPTInForTokenOut                                                                //
            // a = amountOut                                                                        //
            // b = balance                     /      /    totalBPT - bptIn       \\    (1 / w)  \\   //
            // bptIn = bptAmountIn    a = b * |  1 - | --------------------------  | ^           |  //
            // bpt = totalBPT                  \\      \\       totalBPT            /             /   //
            // w = weight                                                                           //
            *****************************************************************************************/
            // Token out, so we round down overall. The multiplication rounds down, but the power rounds up (so the base
            // rounds up). Because (totalBPT - bptIn) / totalBPT <= 1, the exponent rounds down.
            // Calculate the factor by which the invariant will decrease after burning BPTAmountIn
            uint256 invariantRatio = bptTotalSupply.sub(bptAmountIn).divUp(bptTotalSupply);
            _require(invariantRatio >= _MIN_INVARIANT_RATIO, Errors.MIN_BPT_IN_FOR_TOKEN_OUT);
            // Calculate by how much the token balance has to decrease to match invariantRatio
            uint256 balanceRatio = invariantRatio.powUp(FixedPoint.ONE.divDown(normalizedWeight));
            // Because of rounding up, balanceRatio can be greater than one. Using complement prevents reverts.
            uint256 amountOutWithoutFee = balance.mulDown(balanceRatio.complement());
            // We can now compute how much excess balance is being withdrawn as a result of the virtual swaps, which result
            // in swap fees.
            // Swap fees are typically charged on 'token in', but there is no 'token in' here, so we apply it
            // to 'token out'. This results in slightly larger price impact. Fees are rounded up.
            uint256 taxableAmount = amountOutWithoutFee.mulUp(normalizedWeight.complement());
            uint256 nonTaxableAmount = amountOutWithoutFee.sub(taxableAmount);
            uint256 taxableAmountMinusFees = taxableAmount.mulUp(swapFeePercentage.complement());
            return nonTaxableAmount.add(taxableAmountMinusFees);
        }
        function _calcTokensOutGivenExactBptIn(
            uint256[] memory balances,
            uint256 bptAmountIn,
            uint256 totalBPT
        ) internal pure returns (uint256[] memory) {
            /**********************************************************************************************
            // exactBPTInForTokensOut                                                                    //
            // (per token)                                                                               //
            // aO = amountOut                  /        bptIn         \\                                  //
            // b = balance           a0 = b * | ---------------------  |                                 //
            // bptIn = bptAmountIn             \\       totalBPT       /                                  //
            // bpt = totalBPT                                                                            //
            **********************************************************************************************/
            // Since we're computing an amount out, we round down overall. This means rounding down on both the
            // multiplication and division.
            uint256 bptRatio = bptAmountIn.divDown(totalBPT);
            uint256[] memory amountsOut = new uint256[](balances.length);
            for (uint256 i = 0; i < balances.length; i++) {
                amountsOut[i] = balances[i].mulDown(bptRatio);
            }
            return amountsOut;
        }
        /**
         * @dev Calculate the amount of BPT which should be minted when adding a new token to the Pool.
         *
         * Note that normalizedWeight is set that it corresponds to the desired weight of this token *after* adding it.
         * i.e. For a two token 50:50 pool which we want to turn into a 33:33:33 pool, we use a normalized weight of 33%
         * @param totalSupply - the total supply of the Pool's BPT.
         * @param normalizedWeight - the normalized weight of the token to be added (normalized relative to final weights)
         */
        function _calcBptOutAddToken(uint256 totalSupply, uint256 normalizedWeight) internal pure returns (uint256) {
            // The amount of BPT which is equivalent to the token being added may be calculated by the growth in the
            // sum of the token weights, i.e. if we add a token which will make up 50% of the pool then we should receive
            // 50% of the new supply of BPT.
            //
            // The growth in the total weight of the pool can be easily calculated by:
            //
            // weightSumRatio = totalWeight / (totalWeight - newTokenWeight)
            //
            // As we're working with normalized weights `totalWeight` is equal to 1.
            uint256 weightSumRatio = FixedPoint.ONE.divDown(FixedPoint.ONE.sub(normalizedWeight));
            // The amount of BPT to mint is then simply:
            //
            // toMint = totalSupply * (weightSumRatio - 1)
            return totalSupply.mulDown(weightSumRatio.sub(FixedPoint.ONE));
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.7.0;
    /**
     * @dev Interface of the ERC20 standard as defined in the EIP.
     */
    interface IERC20 {
        /**
         * @dev Returns the amount of tokens in existence.
         */
        function totalSupply() external view returns (uint256);
        /**
         * @dev Returns the amount of tokens owned by `account`.
         */
        function balanceOf(address account) external view returns (uint256);
        /**
         * @dev Moves `amount` tokens from the caller's account to `recipient`.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * Emits a {Transfer} event.
         */
        function transfer(address recipient, uint256 amount) external returns (bool);
        /**
         * @dev Returns the remaining number of tokens that `spender` will be
         * allowed to spend on behalf of `owner` through {transferFrom}. This is
         * zero by default.
         *
         * This value changes when {approve} or {transferFrom} are called.
         */
        function allowance(address owner, address spender) external view returns (uint256);
        /**
         * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * IMPORTANT: Beware that changing an allowance with this method brings the risk
         * that someone may use both the old and the new allowance by unfortunate
         * transaction ordering. One possible solution to mitigate this race
         * condition is to first reduce the spender's allowance to 0 and set the
         * desired value afterwards:
         * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
         *
         * Emits an {Approval} event.
         */
        function approve(address spender, uint256 amount) external returns (bool);
        /**
         * @dev Moves `amount` tokens from `sender` to `recipient` using the
         * allowance mechanism. `amount` is then deducted from the caller's
         * allowance.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * Emits a {Transfer} event.
         */
        function transferFrom(
            address sender,
            address recipient,
            uint256 amount
        ) external returns (bool);
        /**
         * @dev Emitted when `value` tokens are moved from one account (`from`) to
         * another (`to`).
         *
         * Note that `value` may be zero.
         */
        event Transfer(address indexed from, address indexed to, uint256 value);
        /**
         * @dev Emitted when the allowance of a `spender` for an `owner` is set by
         * a call to {approve}. `value` is the new allowance.
         */
        event Approval(address indexed owner, address indexed spender, uint256 value);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    // solhint-disable
    /**
     * @dev Reverts if `condition` is false, with a revert reason containing `errorCode`. Only codes up to 999 are
     * supported.
     * Uses the default 'BAL' prefix for the error code
     */
    function _require(bool condition, uint256 errorCode) pure {
        if (!condition) _revert(errorCode);
    }
    /**
     * @dev Reverts if `condition` is false, with a revert reason containing `errorCode`. Only codes up to 999 are
     * supported.
     */
    function _require(bool condition, uint256 errorCode, bytes3 prefix) pure {
        if (!condition) _revert(errorCode, prefix);
    }
    /**
     * @dev Reverts with a revert reason containing `errorCode`. Only codes up to 999 are supported.
     * Uses the default 'BAL' prefix for the error code
     */
    function _revert(uint256 errorCode) pure {
        _revert(errorCode, 0x42414c); // This is the raw byte representation of "BAL"
    }
    /**
     * @dev Reverts with a revert reason containing `errorCode`. Only codes up to 999 are supported.
     */
    function _revert(uint256 errorCode, bytes3 prefix) pure {
        uint256 prefixUint = uint256(uint24(prefix));
        // We're going to dynamically create a revert string based on the error code, with the following format:
        // 'BAL#{errorCode}'
        // where the code is left-padded with zeroes to three digits (so they range from 000 to 999).
        //
        // We don't have revert strings embedded in the contract to save bytecode size: it takes much less space to store a
        // number (8 to 16 bits) than the individual string characters.
        //
        // The dynamic string creation algorithm that follows could be implemented in Solidity, but assembly allows for a
        // much denser implementation, again saving bytecode size. Given this function unconditionally reverts, this is a
        // safe place to rely on it without worrying about how its usage might affect e.g. memory contents.
        assembly {
            // First, we need to compute the ASCII representation of the error code. We assume that it is in the 0-999
            // range, so we only need to convert three digits. To convert the digits to ASCII, we add 0x30, the value for
            // the '0' character.
            let units := add(mod(errorCode, 10), 0x30)
            errorCode := div(errorCode, 10)
            let tenths := add(mod(errorCode, 10), 0x30)
            errorCode := div(errorCode, 10)
            let hundreds := add(mod(errorCode, 10), 0x30)
            // With the individual characters, we can now construct the full string.
            // We first append the '#' character (0x23) to the prefix. In the case of 'BAL', it results in 0x42414c23 ('BAL#')
            // Then, we shift this by 24 (to provide space for the 3 bytes of the error code), and add the
            // characters to it, each shifted by a multiple of 8.
            // The revert reason is then shifted left by 200 bits (256 minus the length of the string, 7 characters * 8 bits
            // per character = 56) to locate it in the most significant part of the 256 slot (the beginning of a byte
            // array).
            let formattedPrefix := shl(24, add(0x23, shl(8, prefixUint)))
            let revertReason := shl(200, add(formattedPrefix, add(add(units, shl(8, tenths)), shl(16, hundreds))))
            // We can now encode the reason in memory, which can be safely overwritten as we're about to revert. The encoded
            // message will have the following layout:
            // [ revert reason identifier ] [ string location offset ] [ string length ] [ string contents ]
            // The Solidity revert reason identifier is 0x08c739a0, the function selector of the Error(string) function. We
            // also write zeroes to the next 28 bytes of memory, but those are about to be overwritten.
            mstore(0x0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
            // Next is the offset to the location of the string, which will be placed immediately after (20 bytes away).
            mstore(0x04, 0x0000000000000000000000000000000000000000000000000000000000000020)
            // The string length is fixed: 7 characters.
            mstore(0x24, 7)
            // Finally, the string itself is stored.
            mstore(0x44, revertReason)
            // Even if the string is only 7 bytes long, we need to return a full 32 byte slot containing it. The length of
            // the encoded message is therefore 4 + 32 + 32 + 32 = 100.
            revert(0, 100)
        }
    }
    library Errors {
        // Math
        uint256 internal constant ADD_OVERFLOW = 0;
        uint256 internal constant SUB_OVERFLOW = 1;
        uint256 internal constant SUB_UNDERFLOW = 2;
        uint256 internal constant MUL_OVERFLOW = 3;
        uint256 internal constant ZERO_DIVISION = 4;
        uint256 internal constant DIV_INTERNAL = 5;
        uint256 internal constant X_OUT_OF_BOUNDS = 6;
        uint256 internal constant Y_OUT_OF_BOUNDS = 7;
        uint256 internal constant PRODUCT_OUT_OF_BOUNDS = 8;
        uint256 internal constant INVALID_EXPONENT = 9;
        // Input
        uint256 internal constant OUT_OF_BOUNDS = 100;
        uint256 internal constant UNSORTED_ARRAY = 101;
        uint256 internal constant UNSORTED_TOKENS = 102;
        uint256 internal constant INPUT_LENGTH_MISMATCH = 103;
        uint256 internal constant ZERO_TOKEN = 104;
        // Shared pools
        uint256 internal constant MIN_TOKENS = 200;
        uint256 internal constant MAX_TOKENS = 201;
        uint256 internal constant MAX_SWAP_FEE_PERCENTAGE = 202;
        uint256 internal constant MIN_SWAP_FEE_PERCENTAGE = 203;
        uint256 internal constant MINIMUM_BPT = 204;
        uint256 internal constant CALLER_NOT_VAULT = 205;
        uint256 internal constant UNINITIALIZED = 206;
        uint256 internal constant BPT_IN_MAX_AMOUNT = 207;
        uint256 internal constant BPT_OUT_MIN_AMOUNT = 208;
        uint256 internal constant EXPIRED_PERMIT = 209;
        uint256 internal constant NOT_TWO_TOKENS = 210;
        uint256 internal constant DISABLED = 211;
        // Pools
        uint256 internal constant MIN_AMP = 300;
        uint256 internal constant MAX_AMP = 301;
        uint256 internal constant MIN_WEIGHT = 302;
        uint256 internal constant MAX_STABLE_TOKENS = 303;
        uint256 internal constant MAX_IN_RATIO = 304;
        uint256 internal constant MAX_OUT_RATIO = 305;
        uint256 internal constant MIN_BPT_IN_FOR_TOKEN_OUT = 306;
        uint256 internal constant MAX_OUT_BPT_FOR_TOKEN_IN = 307;
        uint256 internal constant NORMALIZED_WEIGHT_INVARIANT = 308;
        uint256 internal constant INVALID_TOKEN = 309;
        uint256 internal constant UNHANDLED_JOIN_KIND = 310;
        uint256 internal constant ZERO_INVARIANT = 311;
        uint256 internal constant ORACLE_INVALID_SECONDS_QUERY = 312;
        uint256 internal constant ORACLE_NOT_INITIALIZED = 313;
        uint256 internal constant ORACLE_QUERY_TOO_OLD = 314;
        uint256 internal constant ORACLE_INVALID_INDEX = 315;
        uint256 internal constant ORACLE_BAD_SECS = 316;
        uint256 internal constant AMP_END_TIME_TOO_CLOSE = 317;
        uint256 internal constant AMP_ONGOING_UPDATE = 318;
        uint256 internal constant AMP_RATE_TOO_HIGH = 319;
        uint256 internal constant AMP_NO_ONGOING_UPDATE = 320;
        uint256 internal constant STABLE_INVARIANT_DIDNT_CONVERGE = 321;
        uint256 internal constant STABLE_GET_BALANCE_DIDNT_CONVERGE = 322;
        uint256 internal constant RELAYER_NOT_CONTRACT = 323;
        uint256 internal constant BASE_POOL_RELAYER_NOT_CALLED = 324;
        uint256 internal constant REBALANCING_RELAYER_REENTERED = 325;
        uint256 internal constant GRADUAL_UPDATE_TIME_TRAVEL = 326;
        uint256 internal constant SWAPS_DISABLED = 327;
        uint256 internal constant CALLER_IS_NOT_LBP_OWNER = 328;
        uint256 internal constant PRICE_RATE_OVERFLOW = 329;
        uint256 internal constant INVALID_JOIN_EXIT_KIND_WHILE_SWAPS_DISABLED = 330;
        uint256 internal constant WEIGHT_CHANGE_TOO_FAST = 331;
        uint256 internal constant LOWER_GREATER_THAN_UPPER_TARGET = 332;
        uint256 internal constant UPPER_TARGET_TOO_HIGH = 333;
        uint256 internal constant UNHANDLED_BY_LINEAR_POOL = 334;
        uint256 internal constant OUT_OF_TARGET_RANGE = 335;
        uint256 internal constant UNHANDLED_EXIT_KIND = 336;
        uint256 internal constant UNAUTHORIZED_EXIT = 337;
        uint256 internal constant MAX_MANAGEMENT_SWAP_FEE_PERCENTAGE = 338;
        uint256 internal constant UNHANDLED_BY_MANAGED_POOL = 339;
        uint256 internal constant UNHANDLED_BY_PHANTOM_POOL = 340;
        uint256 internal constant TOKEN_DOES_NOT_HAVE_RATE_PROVIDER = 341;
        uint256 internal constant INVALID_INITIALIZATION = 342;
        uint256 internal constant OUT_OF_NEW_TARGET_RANGE = 343;
        uint256 internal constant FEATURE_DISABLED = 344;
        uint256 internal constant UNINITIALIZED_POOL_CONTROLLER = 345;
        uint256 internal constant SET_SWAP_FEE_DURING_FEE_CHANGE = 346;
        uint256 internal constant SET_SWAP_FEE_PENDING_FEE_CHANGE = 347;
        uint256 internal constant CHANGE_TOKENS_DURING_WEIGHT_CHANGE = 348;
        uint256 internal constant CHANGE_TOKENS_PENDING_WEIGHT_CHANGE = 349;
        uint256 internal constant MAX_WEIGHT = 350;
        uint256 internal constant UNAUTHORIZED_JOIN = 351;
        uint256 internal constant MAX_MANAGEMENT_AUM_FEE_PERCENTAGE = 352;
        uint256 internal constant FRACTIONAL_TARGET = 353;
        // Lib
        uint256 internal constant REENTRANCY = 400;
        uint256 internal constant SENDER_NOT_ALLOWED = 401;
        uint256 internal constant PAUSED = 402;
        uint256 internal constant PAUSE_WINDOW_EXPIRED = 403;
        uint256 internal constant MAX_PAUSE_WINDOW_DURATION = 404;
        uint256 internal constant MAX_BUFFER_PERIOD_DURATION = 405;
        uint256 internal constant INSUFFICIENT_BALANCE = 406;
        uint256 internal constant INSUFFICIENT_ALLOWANCE = 407;
        uint256 internal constant ERC20_TRANSFER_FROM_ZERO_ADDRESS = 408;
        uint256 internal constant ERC20_TRANSFER_TO_ZERO_ADDRESS = 409;
        uint256 internal constant ERC20_MINT_TO_ZERO_ADDRESS = 410;
        uint256 internal constant ERC20_BURN_FROM_ZERO_ADDRESS = 411;
        uint256 internal constant ERC20_APPROVE_FROM_ZERO_ADDRESS = 412;
        uint256 internal constant ERC20_APPROVE_TO_ZERO_ADDRESS = 413;
        uint256 internal constant ERC20_TRANSFER_EXCEEDS_ALLOWANCE = 414;
        uint256 internal constant ERC20_DECREASED_ALLOWANCE_BELOW_ZERO = 415;
        uint256 internal constant ERC20_TRANSFER_EXCEEDS_BALANCE = 416;
        uint256 internal constant ERC20_BURN_EXCEEDS_ALLOWANCE = 417;
        uint256 internal constant SAFE_ERC20_CALL_FAILED = 418;
        uint256 internal constant ADDRESS_INSUFFICIENT_BALANCE = 419;
        uint256 internal constant ADDRESS_CANNOT_SEND_VALUE = 420;
        uint256 internal constant SAFE_CAST_VALUE_CANT_FIT_INT256 = 421;
        uint256 internal constant GRANT_SENDER_NOT_ADMIN = 422;
        uint256 internal constant REVOKE_SENDER_NOT_ADMIN = 423;
        uint256 internal constant RENOUNCE_SENDER_NOT_ALLOWED = 424;
        uint256 internal constant BUFFER_PERIOD_EXPIRED = 425;
        uint256 internal constant CALLER_IS_NOT_OWNER = 426;
        uint256 internal constant NEW_OWNER_IS_ZERO = 427;
        uint256 internal constant CODE_DEPLOYMENT_FAILED = 428;
        uint256 internal constant CALL_TO_NON_CONTRACT = 429;
        uint256 internal constant LOW_LEVEL_CALL_FAILED = 430;
        uint256 internal constant NOT_PAUSED = 431;
        uint256 internal constant ADDRESS_ALREADY_ALLOWLISTED = 432;
        uint256 internal constant ADDRESS_NOT_ALLOWLISTED = 433;
        uint256 internal constant ERC20_BURN_EXCEEDS_BALANCE = 434;
        uint256 internal constant INVALID_OPERATION = 435;
        uint256 internal constant CODEC_OVERFLOW = 436;
        uint256 internal constant IN_RECOVERY_MODE = 437;
        uint256 internal constant NOT_IN_RECOVERY_MODE = 438;
        uint256 internal constant INDUCED_FAILURE = 439;
        uint256 internal constant EXPIRED_SIGNATURE = 440;
        uint256 internal constant MALFORMED_SIGNATURE = 441;
        uint256 internal constant SAFE_CAST_VALUE_CANT_FIT_UINT64 = 442;
        uint256 internal constant UNHANDLED_FEE_TYPE = 443;
        // Vault
        uint256 internal constant INVALID_POOL_ID = 500;
        uint256 internal constant CALLER_NOT_POOL = 501;
        uint256 internal constant SENDER_NOT_ASSET_MANAGER = 502;
        uint256 internal constant USER_DOESNT_ALLOW_RELAYER = 503;
        uint256 internal constant INVALID_SIGNATURE = 504;
        uint256 internal constant EXIT_BELOW_MIN = 505;
        uint256 internal constant JOIN_ABOVE_MAX = 506;
        uint256 internal constant SWAP_LIMIT = 507;
        uint256 internal constant SWAP_DEADLINE = 508;
        uint256 internal constant CANNOT_SWAP_SAME_TOKEN = 509;
        uint256 internal constant UNKNOWN_AMOUNT_IN_FIRST_SWAP = 510;
        uint256 internal constant MALCONSTRUCTED_MULTIHOP_SWAP = 511;
        uint256 internal constant INTERNAL_BALANCE_OVERFLOW = 512;
        uint256 internal constant INSUFFICIENT_INTERNAL_BALANCE = 513;
        uint256 internal constant INVALID_ETH_INTERNAL_BALANCE = 514;
        uint256 internal constant INVALID_POST_LOAN_BALANCE = 515;
        uint256 internal constant INSUFFICIENT_ETH = 516;
        uint256 internal constant UNALLOCATED_ETH = 517;
        uint256 internal constant ETH_TRANSFER = 518;
        uint256 internal constant CANNOT_USE_ETH_SENTINEL = 519;
        uint256 internal constant TOKENS_MISMATCH = 520;
        uint256 internal constant TOKEN_NOT_REGISTERED = 521;
        uint256 internal constant TOKEN_ALREADY_REGISTERED = 522;
        uint256 internal constant TOKENS_ALREADY_SET = 523;
        uint256 internal constant TOKENS_LENGTH_MUST_BE_2 = 524;
        uint256 internal constant NONZERO_TOKEN_BALANCE = 525;
        uint256 internal constant BALANCE_TOTAL_OVERFLOW = 526;
        uint256 internal constant POOL_NO_TOKENS = 527;
        uint256 internal constant INSUFFICIENT_FLASH_LOAN_BALANCE = 528;
        // Fees
        uint256 internal constant SWAP_FEE_PERCENTAGE_TOO_HIGH = 600;
        uint256 internal constant FLASH_LOAN_FEE_PERCENTAGE_TOO_HIGH = 601;
        uint256 internal constant INSUFFICIENT_FLASH_LOAN_FEE_AMOUNT = 602;
        uint256 internal constant AUM_FEE_PERCENTAGE_TOO_HIGH = 603;
        // Misc
        uint256 internal constant UNIMPLEMENTED = 998;
        uint256 internal constant SHOULD_NOT_HAPPEN = 999;
    }
    // SPDX-License-Identifier: MIT
    // Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
    // documentation files (the “Software”), to deal in the Software without restriction, including without limitation the
    // rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
    // permit persons to whom the Software is furnished to do so, subject to the following conditions:
    // The above copyright notice and this permission notice shall be included in all copies or substantial portions of the
    // Software.
    // THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
    // WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
    // COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
    // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    /* solhint-disable */
    /**
     * @dev Exponentiation and logarithm functions for 18 decimal fixed point numbers (both base and exponent/argument).
     *
     * Exponentiation and logarithm with arbitrary bases (x^y and log_x(y)) are implemented by conversion to natural
     * exponentiation and logarithm (where the base is Euler's number).
     *
     * @author Fernando Martinelli - @fernandomartinelli
     * @author Sergio Yuhjtman - @sergioyuhjtman
     * @author Daniel Fernandez - @dmf7z
     */
    library LogExpMath {
        // All fixed point multiplications and divisions are inlined. This means we need to divide by ONE when multiplying
        // two numbers, and multiply by ONE when dividing them.
        // All arguments and return values are 18 decimal fixed point numbers.
        int256 constant ONE_18 = 1e18;
        // Internally, intermediate values are computed with higher precision as 20 decimal fixed point numbers, and in the
        // case of ln36, 36 decimals.
        int256 constant ONE_20 = 1e20;
        int256 constant ONE_36 = 1e36;
        // The domain of natural exponentiation is bound by the word size and number of decimals used.
        //
        // Because internally the result will be stored using 20 decimals, the largest possible result is
        // (2^255 - 1) / 10^20, which makes the largest exponent ln((2^255 - 1) / 10^20) = 130.700829182905140221.
        // The smallest possible result is 10^(-18), which makes largest negative argument
        // ln(10^(-18)) = -41.446531673892822312.
        // We use 130.0 and -41.0 to have some safety margin.
        int256 constant MAX_NATURAL_EXPONENT = 130e18;
        int256 constant MIN_NATURAL_EXPONENT = -41e18;
        // Bounds for ln_36's argument. Both ln(0.9) and ln(1.1) can be represented with 36 decimal places in a fixed point
        // 256 bit integer.
        int256 constant LN_36_LOWER_BOUND = ONE_18 - 1e17;
        int256 constant LN_36_UPPER_BOUND = ONE_18 + 1e17;
        uint256 constant MILD_EXPONENT_BOUND = 2**254 / uint256(ONE_20);
        // 18 decimal constants
        int256 constant x0 = 128000000000000000000; // 2ˆ7
        int256 constant a0 = 38877084059945950922200000000000000000000000000000000000; // eˆ(x0) (no decimals)
        int256 constant x1 = 64000000000000000000; // 2ˆ6
        int256 constant a1 = 6235149080811616882910000000; // eˆ(x1) (no decimals)
        // 20 decimal constants
        int256 constant x2 = 3200000000000000000000; // 2ˆ5
        int256 constant a2 = 7896296018268069516100000000000000; // eˆ(x2)
        int256 constant x3 = 1600000000000000000000; // 2ˆ4
        int256 constant a3 = 888611052050787263676000000; // eˆ(x3)
        int256 constant x4 = 800000000000000000000; // 2ˆ3
        int256 constant a4 = 298095798704172827474000; // eˆ(x4)
        int256 constant x5 = 400000000000000000000; // 2ˆ2
        int256 constant a5 = 5459815003314423907810; // eˆ(x5)
        int256 constant x6 = 200000000000000000000; // 2ˆ1
        int256 constant a6 = 738905609893065022723; // eˆ(x6)
        int256 constant x7 = 100000000000000000000; // 2ˆ0
        int256 constant a7 = 271828182845904523536; // eˆ(x7)
        int256 constant x8 = 50000000000000000000; // 2ˆ-1
        int256 constant a8 = 164872127070012814685; // eˆ(x8)
        int256 constant x9 = 25000000000000000000; // 2ˆ-2
        int256 constant a9 = 128402541668774148407; // eˆ(x9)
        int256 constant x10 = 12500000000000000000; // 2ˆ-3
        int256 constant a10 = 113314845306682631683; // eˆ(x10)
        int256 constant x11 = 6250000000000000000; // 2ˆ-4
        int256 constant a11 = 106449445891785942956; // eˆ(x11)
        /**
         * @dev Exponentiation (x^y) with unsigned 18 decimal fixed point base and exponent.
         *
         * Reverts if ln(x) * y is smaller than `MIN_NATURAL_EXPONENT`, or larger than `MAX_NATURAL_EXPONENT`.
         */
        function pow(uint256 x, uint256 y) internal pure returns (uint256) {
            if (y == 0) {
                // We solve the 0^0 indetermination by making it equal one.
                return uint256(ONE_18);
            }
            if (x == 0) {
                return 0;
            }
            // Instead of computing x^y directly, we instead rely on the properties of logarithms and exponentiation to
            // arrive at that result. In particular, exp(ln(x)) = x, and ln(x^y) = y * ln(x). This means
            // x^y = exp(y * ln(x)).
            // The ln function takes a signed value, so we need to make sure x fits in the signed 256 bit range.
            _require(x >> 255 == 0, Errors.X_OUT_OF_BOUNDS);
            int256 x_int256 = int256(x);
            // We will compute y * ln(x) in a single step. Depending on the value of x, we can either use ln or ln_36. In
            // both cases, we leave the division by ONE_18 (due to fixed point multiplication) to the end.
            // This prevents y * ln(x) from overflowing, and at the same time guarantees y fits in the signed 256 bit range.
            _require(y < MILD_EXPONENT_BOUND, Errors.Y_OUT_OF_BOUNDS);
            int256 y_int256 = int256(y);
            int256 logx_times_y;
            if (LN_36_LOWER_BOUND < x_int256 && x_int256 < LN_36_UPPER_BOUND) {
                int256 ln_36_x = _ln_36(x_int256);
                // ln_36_x has 36 decimal places, so multiplying by y_int256 isn't as straightforward, since we can't just
                // bring y_int256 to 36 decimal places, as it might overflow. Instead, we perform two 18 decimal
                // multiplications and add the results: one with the first 18 decimals of ln_36_x, and one with the
                // (downscaled) last 18 decimals.
                logx_times_y = ((ln_36_x / ONE_18) * y_int256 + ((ln_36_x % ONE_18) * y_int256) / ONE_18);
            } else {
                logx_times_y = _ln(x_int256) * y_int256;
            }
            logx_times_y /= ONE_18;
            // Finally, we compute exp(y * ln(x)) to arrive at x^y
            _require(
                MIN_NATURAL_EXPONENT <= logx_times_y && logx_times_y <= MAX_NATURAL_EXPONENT,
                Errors.PRODUCT_OUT_OF_BOUNDS
            );
            return uint256(exp(logx_times_y));
        }
        /**
         * @dev Natural exponentiation (e^x) with signed 18 decimal fixed point exponent.
         *
         * Reverts if `x` is smaller than MIN_NATURAL_EXPONENT, or larger than `MAX_NATURAL_EXPONENT`.
         */
        function exp(int256 x) internal pure returns (int256) {
            _require(x >= MIN_NATURAL_EXPONENT && x <= MAX_NATURAL_EXPONENT, Errors.INVALID_EXPONENT);
            if (x < 0) {
                // We only handle positive exponents: e^(-x) is computed as 1 / e^x. We can safely make x positive since it
                // fits in the signed 256 bit range (as it is larger than MIN_NATURAL_EXPONENT).
                // Fixed point division requires multiplying by ONE_18.
                return ((ONE_18 * ONE_18) / exp(-x));
            }
            // First, we use the fact that e^(x+y) = e^x * e^y to decompose x into a sum of powers of two, which we call x_n,
            // where x_n == 2^(7 - n), and e^x_n = a_n has been precomputed. We choose the first x_n, x0, to equal 2^7
            // because all larger powers are larger than MAX_NATURAL_EXPONENT, and therefore not present in the
            // decomposition.
            // At the end of this process we will have the product of all e^x_n = a_n that apply, and the remainder of this
            // decomposition, which will be lower than the smallest x_n.
            // exp(x) = k_0 * a_0 * k_1 * a_1 * ... + k_n * a_n * exp(remainder), where each k_n equals either 0 or 1.
            // We mutate x by subtracting x_n, making it the remainder of the decomposition.
            // The first two a_n (e^(2^7) and e^(2^6)) are too large if stored as 18 decimal numbers, and could cause
            // intermediate overflows. Instead we store them as plain integers, with 0 decimals.
            // Additionally, x0 + x1 is larger than MAX_NATURAL_EXPONENT, which means they will not both be present in the
            // decomposition.
            // For each x_n, we test if that term is present in the decomposition (if x is larger than it), and if so deduct
            // it and compute the accumulated product.
            int256 firstAN;
            if (x >= x0) {
                x -= x0;
                firstAN = a0;
            } else if (x >= x1) {
                x -= x1;
                firstAN = a1;
            } else {
                firstAN = 1; // One with no decimal places
            }
            // We now transform x into a 20 decimal fixed point number, to have enhanced precision when computing the
            // smaller terms.
            x *= 100;
            // `product` is the accumulated product of all a_n (except a0 and a1), which starts at 20 decimal fixed point
            // one. Recall that fixed point multiplication requires dividing by ONE_20.
            int256 product = ONE_20;
            if (x >= x2) {
                x -= x2;
                product = (product * a2) / ONE_20;
            }
            if (x >= x3) {
                x -= x3;
                product = (product * a3) / ONE_20;
            }
            if (x >= x4) {
                x -= x4;
                product = (product * a4) / ONE_20;
            }
            if (x >= x5) {
                x -= x5;
                product = (product * a5) / ONE_20;
            }
            if (x >= x6) {
                x -= x6;
                product = (product * a6) / ONE_20;
            }
            if (x >= x7) {
                x -= x7;
                product = (product * a7) / ONE_20;
            }
            if (x >= x8) {
                x -= x8;
                product = (product * a8) / ONE_20;
            }
            if (x >= x9) {
                x -= x9;
                product = (product * a9) / ONE_20;
            }
            // x10 and x11 are unnecessary here since we have high enough precision already.
            // Now we need to compute e^x, where x is small (in particular, it is smaller than x9). We use the Taylor series
            // expansion for e^x: 1 + x + (x^2 / 2!) + (x^3 / 3!) + ... + (x^n / n!).
            int256 seriesSum = ONE_20; // The initial one in the sum, with 20 decimal places.
            int256 term; // Each term in the sum, where the nth term is (x^n / n!).
            // The first term is simply x.
            term = x;
            seriesSum += term;
            // Each term (x^n / n!) equals the previous one times x, divided by n. Since x is a fixed point number,
            // multiplying by it requires dividing by ONE_20, but dividing by the non-fixed point n values does not.
            term = ((term * x) / ONE_20) / 2;
            seriesSum += term;
            term = ((term * x) / ONE_20) / 3;
            seriesSum += term;
            term = ((term * x) / ONE_20) / 4;
            seriesSum += term;
            term = ((term * x) / ONE_20) / 5;
            seriesSum += term;
            term = ((term * x) / ONE_20) / 6;
            seriesSum += term;
            term = ((term * x) / ONE_20) / 7;
            seriesSum += term;
            term = ((term * x) / ONE_20) / 8;
            seriesSum += term;
            term = ((term * x) / ONE_20) / 9;
            seriesSum += term;
            term = ((term * x) / ONE_20) / 10;
            seriesSum += term;
            term = ((term * x) / ONE_20) / 11;
            seriesSum += term;
            term = ((term * x) / ONE_20) / 12;
            seriesSum += term;
            // 12 Taylor terms are sufficient for 18 decimal precision.
            // We now have the first a_n (with no decimals), and the product of all other a_n present, and the Taylor
            // approximation of the exponentiation of the remainder (both with 20 decimals). All that remains is to multiply
            // all three (one 20 decimal fixed point multiplication, dividing by ONE_20, and one integer multiplication),
            // and then drop two digits to return an 18 decimal value.
            return (((product * seriesSum) / ONE_20) * firstAN) / 100;
        }
        /**
         * @dev Logarithm (log(arg, base), with signed 18 decimal fixed point base and argument.
         */
        function log(int256 arg, int256 base) internal pure returns (int256) {
            // This performs a simple base change: log(arg, base) = ln(arg) / ln(base).
            // Both logBase and logArg are computed as 36 decimal fixed point numbers, either by using ln_36, or by
            // upscaling.
            int256 logBase;
            if (LN_36_LOWER_BOUND < base && base < LN_36_UPPER_BOUND) {
                logBase = _ln_36(base);
            } else {
                logBase = _ln(base) * ONE_18;
            }
            int256 logArg;
            if (LN_36_LOWER_BOUND < arg && arg < LN_36_UPPER_BOUND) {
                logArg = _ln_36(arg);
            } else {
                logArg = _ln(arg) * ONE_18;
            }
            // When dividing, we multiply by ONE_18 to arrive at a result with 18 decimal places
            return (logArg * ONE_18) / logBase;
        }
        /**
         * @dev Natural logarithm (ln(a)) with signed 18 decimal fixed point argument.
         */
        function ln(int256 a) internal pure returns (int256) {
            // The real natural logarithm is not defined for negative numbers or zero.
            _require(a > 0, Errors.OUT_OF_BOUNDS);
            if (LN_36_LOWER_BOUND < a && a < LN_36_UPPER_BOUND) {
                return _ln_36(a) / ONE_18;
            } else {
                return _ln(a);
            }
        }
        /**
         * @dev Internal natural logarithm (ln(a)) with signed 18 decimal fixed point argument.
         */
        function _ln(int256 a) private pure returns (int256) {
            if (a < ONE_18) {
                // Since ln(a^k) = k * ln(a), we can compute ln(a) as ln(a) = ln((1/a)^(-1)) = - ln((1/a)). If a is less
                // than one, 1/a will be greater than one, and this if statement will not be entered in the recursive call.
                // Fixed point division requires multiplying by ONE_18.
                return (-_ln((ONE_18 * ONE_18) / a));
            }
            // First, we use the fact that ln^(a * b) = ln(a) + ln(b) to decompose ln(a) into a sum of powers of two, which
            // we call x_n, where x_n == 2^(7 - n), which are the natural logarithm of precomputed quantities a_n (that is,
            // ln(a_n) = x_n). We choose the first x_n, x0, to equal 2^7 because the exponential of all larger powers cannot
            // be represented as 18 fixed point decimal numbers in 256 bits, and are therefore larger than a.
            // At the end of this process we will have the sum of all x_n = ln(a_n) that apply, and the remainder of this
            // decomposition, which will be lower than the smallest a_n.
            // ln(a) = k_0 * x_0 + k_1 * x_1 + ... + k_n * x_n + ln(remainder), where each k_n equals either 0 or 1.
            // We mutate a by subtracting a_n, making it the remainder of the decomposition.
            // For reasons related to how `exp` works, the first two a_n (e^(2^7) and e^(2^6)) are not stored as fixed point
            // numbers with 18 decimals, but instead as plain integers with 0 decimals, so we need to multiply them by
            // ONE_18 to convert them to fixed point.
            // For each a_n, we test if that term is present in the decomposition (if a is larger than it), and if so divide
            // by it and compute the accumulated sum.
            int256 sum = 0;
            if (a >= a0 * ONE_18) {
                a /= a0; // Integer, not fixed point division
                sum += x0;
            }
            if (a >= a1 * ONE_18) {
                a /= a1; // Integer, not fixed point division
                sum += x1;
            }
            // All other a_n and x_n are stored as 20 digit fixed point numbers, so we convert the sum and a to this format.
            sum *= 100;
            a *= 100;
            // Because further a_n are  20 digit fixed point numbers, we multiply by ONE_20 when dividing by them.
            if (a >= a2) {
                a = (a * ONE_20) / a2;
                sum += x2;
            }
            if (a >= a3) {
                a = (a * ONE_20) / a3;
                sum += x3;
            }
            if (a >= a4) {
                a = (a * ONE_20) / a4;
                sum += x4;
            }
            if (a >= a5) {
                a = (a * ONE_20) / a5;
                sum += x5;
            }
            if (a >= a6) {
                a = (a * ONE_20) / a6;
                sum += x6;
            }
            if (a >= a7) {
                a = (a * ONE_20) / a7;
                sum += x7;
            }
            if (a >= a8) {
                a = (a * ONE_20) / a8;
                sum += x8;
            }
            if (a >= a9) {
                a = (a * ONE_20) / a9;
                sum += x9;
            }
            if (a >= a10) {
                a = (a * ONE_20) / a10;
                sum += x10;
            }
            if (a >= a11) {
                a = (a * ONE_20) / a11;
                sum += x11;
            }
            // a is now a small number (smaller than a_11, which roughly equals 1.06). This means we can use a Taylor series
            // that converges rapidly for values of `a` close to one - the same one used in ln_36.
            // Let z = (a - 1) / (a + 1).
            // ln(a) = 2 * (z + z^3 / 3 + z^5 / 5 + z^7 / 7 + ... + z^(2 * n + 1) / (2 * n + 1))
            // Recall that 20 digit fixed point division requires multiplying by ONE_20, and multiplication requires
            // division by ONE_20.
            int256 z = ((a - ONE_20) * ONE_20) / (a + ONE_20);
            int256 z_squared = (z * z) / ONE_20;
            // num is the numerator of the series: the z^(2 * n + 1) term
            int256 num = z;
            // seriesSum holds the accumulated sum of each term in the series, starting with the initial z
            int256 seriesSum = num;
            // In each step, the numerator is multiplied by z^2
            num = (num * z_squared) / ONE_20;
            seriesSum += num / 3;
            num = (num * z_squared) / ONE_20;
            seriesSum += num / 5;
            num = (num * z_squared) / ONE_20;
            seriesSum += num / 7;
            num = (num * z_squared) / ONE_20;
            seriesSum += num / 9;
            num = (num * z_squared) / ONE_20;
            seriesSum += num / 11;
            // 6 Taylor terms are sufficient for 36 decimal precision.
            // Finally, we multiply by 2 (non fixed point) to compute ln(remainder)
            seriesSum *= 2;
            // We now have the sum of all x_n present, and the Taylor approximation of the logarithm of the remainder (both
            // with 20 decimals). All that remains is to sum these two, and then drop two digits to return a 18 decimal
            // value.
            return (sum + seriesSum) / 100;
        }
        /**
         * @dev Intrnal high precision (36 decimal places) natural logarithm (ln(x)) with signed 18 decimal fixed point argument,
         * for x close to one.
         *
         * Should only be used if x is between LN_36_LOWER_BOUND and LN_36_UPPER_BOUND.
         */
        function _ln_36(int256 x) private pure returns (int256) {
            // Since ln(1) = 0, a value of x close to one will yield a very small result, which makes using 36 digits
            // worthwhile.
            // First, we transform x to a 36 digit fixed point value.
            x *= ONE_18;
            // We will use the following Taylor expansion, which converges very rapidly. Let z = (x - 1) / (x + 1).
            // ln(x) = 2 * (z + z^3 / 3 + z^5 / 5 + z^7 / 7 + ... + z^(2 * n + 1) / (2 * n + 1))
            // Recall that 36 digit fixed point division requires multiplying by ONE_36, and multiplication requires
            // division by ONE_36.
            int256 z = ((x - ONE_36) * ONE_36) / (x + ONE_36);
            int256 z_squared = (z * z) / ONE_36;
            // num is the numerator of the series: the z^(2 * n + 1) term
            int256 num = z;
            // seriesSum holds the accumulated sum of each term in the series, starting with the initial z
            int256 seriesSum = num;
            // In each step, the numerator is multiplied by z^2
            num = (num * z_squared) / ONE_36;
            seriesSum += num / 3;
            num = (num * z_squared) / ONE_36;
            seriesSum += num / 5;
            num = (num * z_squared) / ONE_36;
            seriesSum += num / 7;
            num = (num * z_squared) / ONE_36;
            seriesSum += num / 9;
            num = (num * z_squared) / ONE_36;
            seriesSum += num / 11;
            num = (num * z_squared) / ONE_36;
            seriesSum += num / 13;
            num = (num * z_squared) / ONE_36;
            seriesSum += num / 15;
            // 8 Taylor terms are sufficient for 36 decimal precision.
            // All that remains is multiplying by 2 (non fixed point).
            return seriesSum * 2;
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "./IBasePool.sol";
    /**
     * @dev Pool contracts with the MinimalSwapInfo or TwoToken specialization settings should implement this interface.
     *
     * This is called by the Vault when a user calls `IVault.swap` or `IVault.batchSwap` to swap with this Pool.
     * Returns the number of tokens the Pool will grant to the user in a 'given in' swap, or that the user will grant
     * to the pool in a 'given out' swap.
     *
     * This can often be implemented by a `view` function, since many pricing algorithms don't need to track state
     * changes in swaps. However, contracts implementing this in non-view functions should check that the caller is
     * indeed the Vault.
     */
    interface IMinimalSwapInfoPool is IBasePool {
        function onSwap(
            SwapRequest memory swapRequest,
            uint256 currentBalanceTokenIn,
            uint256 currentBalanceTokenOut
        ) external returns (uint256 amount);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "@balancer-labs/v2-interfaces/contracts/pool-utils/IAssetManager.sol";
    import "@balancer-labs/v2-interfaces/contracts/pool-utils/IControlledPool.sol";
    import "@balancer-labs/v2-interfaces/contracts/vault/IVault.sol";
    import "@balancer-labs/v2-interfaces/contracts/vault/IBasePool.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/helpers/InputHelpers.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/helpers/WordCodec.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/helpers/TemporarilyPausable.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/ERC20.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/math/FixedPoint.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/math/Math.sol";
    import "./BalancerPoolToken.sol";
    import "./BasePoolAuthorization.sol";
    import "./RecoveryMode.sol";
    // solhint-disable max-states-count
    /**
     * @notice Reference implementation for the base layer of a Pool contract.
     * @dev Reference implementation for the base layer of a Pool contract that manages a single Pool with optional
     * Asset Managers, an admin-controlled swap fee percentage, and an emergency pause mechanism.
     *
     * This Pool pays protocol fees by minting BPT directly to the ProtocolFeeCollector instead of using the
     * `dueProtocolFees` return value. This results in the underlying tokens continuing to provide liquidity
     * for traders, while still keeping gas usage to a minimum since only a single token (the BPT) is transferred.
     *
     * Note that neither swap fees nor the pause mechanism are used by this contract. They are passed through so that
     * derived contracts can use them via the `_addSwapFeeAmount` and `_subtractSwapFeeAmount` functions, and the
     * `whenNotPaused` modifier.
     *
     * No admin permissions are checked here: instead, this contract delegates that to the Vault's own Authorizer.
     *
     * Because this contract doesn't implement the swap hooks, derived contracts should generally inherit from
     * BaseGeneralPool or BaseMinimalSwapInfoPool. Otherwise, subclasses must inherit from the corresponding interfaces
     * and implement the swap callbacks themselves.
     */
    abstract contract BasePool is
        IBasePool,
        IControlledPool,
        BasePoolAuthorization,
        BalancerPoolToken,
        TemporarilyPausable,
        RecoveryMode
    {
        using WordCodec for bytes32;
        using FixedPoint for uint256;
        using BasePoolUserData for bytes;
        uint256 private constant _MIN_TOKENS = 2;
        uint256 private constant _DEFAULT_MINIMUM_BPT = 1e6;
        // 1e18 corresponds to 1.0, or a 100% fee
        uint256 private constant _MIN_SWAP_FEE_PERCENTAGE = 1e12; // 0.0001%
        uint256 private constant _MAX_SWAP_FEE_PERCENTAGE = 1e17; // 10% - this fits in 64 bits
        // `_miscData` is a storage slot that can be used to store unrelated pieces of information. All pools store the
        // recovery mode flag and swap fee percentage, but `miscData` can be extended to store more pieces of information.
        // The most signficant bit is reserved for the recovery mode flag, and the swap fee percentage is stored in
        // the next most significant 63 bits, leaving the remaining 192 bits free to store any other information derived
        // pools might need.
        //
        // This slot is preferred for gas-sensitive operations as it is read in all joins, swaps and exits,
        // and therefore warm.
        // [ recovery | swap  fee | available ]
        // [   1 bit  |  63 bits  |  192 bits ]
        // [ MSB                          LSB ]
        bytes32 private _miscData;
        uint256 private constant _SWAP_FEE_PERCENTAGE_OFFSET = 192;
        uint256 private constant _RECOVERY_MODE_BIT_OFFSET = 255;
        // A fee can never be larger than FixedPoint.ONE, which fits in 60 bits, so 63 is more than enough.
        uint256 private constant _SWAP_FEE_PERCENTAGE_BIT_LENGTH = 63;
        bytes32 private immutable _poolId;
        // Note that this value is immutable in the Vault, so we can make it immutable here and save gas
        IProtocolFeesCollector private immutable _protocolFeesCollector;
        event SwapFeePercentageChanged(uint256 swapFeePercentage);
        constructor(
            IVault vault,
            IVault.PoolSpecialization specialization,
            string memory name,
            string memory symbol,
            IERC20[] memory tokens,
            address[] memory assetManagers,
            uint256 swapFeePercentage,
            uint256 pauseWindowDuration,
            uint256 bufferPeriodDuration,
            address owner
        )
            // Base Pools are expected to be deployed using factories. By using the factory address as the action
            // disambiguator, we make all Pools deployed by the same factory share action identifiers. This allows for
            // simpler management of permissions (such as being able to manage granting the 'set fee percentage' action in
            // any Pool created by the same factory), while still making action identifiers unique among different factories
            // if the selectors match, preventing accidental errors.
            Authentication(bytes32(uint256(msg.sender)))
            BalancerPoolToken(name, symbol, vault)
            BasePoolAuthorization(owner)
            TemporarilyPausable(pauseWindowDuration, bufferPeriodDuration)
        {
            _require(tokens.length >= _MIN_TOKENS, Errors.MIN_TOKENS);
            _require(tokens.length <= _getMaxTokens(), Errors.MAX_TOKENS);
            // The Vault only requires the token list to be ordered for the Two Token Pools specialization. However,
            // to make the developer experience consistent, we are requiring this condition for all the native pools.
            // Also, since these Pools will register tokens only once, we can ensure the Pool tokens will follow the same
            // order. We rely on this property to make Pools simpler to write, as it lets us assume that the
            // order of token-specific parameters (such as token weights) will not change.
            InputHelpers.ensureArrayIsSorted(tokens);
            _setSwapFeePercentage(swapFeePercentage);
            bytes32 poolId = vault.registerPool(specialization);
            vault.registerTokens(poolId, tokens, assetManagers);
            // Set immutable state variables - these cannot be read from during construction
            _poolId = poolId;
            _protocolFeesCollector = vault.getProtocolFeesCollector();
        }
        // Getters / Setters
        /**
         * @notice Return the pool id.
         */
        function getPoolId() public view override returns (bytes32) {
            return _poolId;
        }
        function _getTotalTokens() internal view virtual returns (uint256);
        function _getMaxTokens() internal pure virtual returns (uint256);
        /**
         * @dev Returns the minimum BPT supply. This amount is minted to the zero address during initialization, effectively
         * locking it.
         *
         * This is useful to make sure Pool initialization happens only once, but derived Pools can change this value (even
         * to zero) by overriding this function.
         */
        function _getMinimumBpt() internal pure virtual returns (uint256) {
            return _DEFAULT_MINIMUM_BPT;
        }
        /**
         * @notice Return the current value of the swap fee percentage.
         * @dev This is stored in `_miscData`.
         */
        function getSwapFeePercentage() public view virtual override returns (uint256) {
            return _miscData.decodeUint(_SWAP_FEE_PERCENTAGE_OFFSET, _SWAP_FEE_PERCENTAGE_BIT_LENGTH);
        }
        /**
         * @notice Return the ProtocolFeesCollector contract.
         * @dev This is immutable, and retrieved from the Vault on construction. (It is also immutable in the Vault.)
         */
        function getProtocolFeesCollector() public view returns (IProtocolFeesCollector) {
            return _protocolFeesCollector;
        }
        /**
         * @notice Set the swap fee percentage.
         * @dev This is a permissioned function, and disabled if the pool is paused. The swap fee must be within the
         * bounds set by MIN_SWAP_FEE_PERCENTAGE/MAX_SWAP_FEE_PERCENTAGE. Emits the SwapFeePercentageChanged event.
         */
        function setSwapFeePercentage(uint256 swapFeePercentage) public virtual override authenticate whenNotPaused {
            _setSwapFeePercentage(swapFeePercentage);
        }
        function _setSwapFeePercentage(uint256 swapFeePercentage) internal virtual {
            _require(swapFeePercentage >= _getMinSwapFeePercentage(), Errors.MIN_SWAP_FEE_PERCENTAGE);
            _require(swapFeePercentage <= _getMaxSwapFeePercentage(), Errors.MAX_SWAP_FEE_PERCENTAGE);
            _miscData = _miscData.insertUint(
                swapFeePercentage,
                _SWAP_FEE_PERCENTAGE_OFFSET,
                _SWAP_FEE_PERCENTAGE_BIT_LENGTH
            );
            emit SwapFeePercentageChanged(swapFeePercentage);
        }
        function _getMinSwapFeePercentage() internal pure virtual returns (uint256) {
            return _MIN_SWAP_FEE_PERCENTAGE;
        }
        function _getMaxSwapFeePercentage() internal pure virtual returns (uint256) {
            return _MAX_SWAP_FEE_PERCENTAGE;
        }
        /**
         * @notice Returns whether the pool is in Recovery Mode.
         */
        function inRecoveryMode() public view override returns (bool) {
            return _miscData.decodeBool(_RECOVERY_MODE_BIT_OFFSET);
        }
        /**
         * @dev Sets the recoveryMode state, and emits the corresponding event.
         */
        function _setRecoveryMode(bool enabled) internal virtual override {
            _miscData = _miscData.insertBool(enabled, _RECOVERY_MODE_BIT_OFFSET);
            emit RecoveryModeStateChanged(enabled);
            // Some pools need to update their state when leaving recovery mode to ensure proper functioning of the Pool.
            // We do not allow an `_onEnableRecoveryMode()` hook as this may jeopardize the ability to enable Recovery mode.
            if (!enabled) _onDisableRecoveryMode();
        }
        /**
         * @dev Performs any necessary actions on the disabling of Recovery Mode.
         * This is usually to reset any fee collection mechanisms to ensure that they operate correctly going forward.
         */
        function _onDisableRecoveryMode() internal virtual {
            // solhint-disable-previous-line no-empty-blocks
        }
        /**
         * @notice Set the asset manager parameters for the given token.
         * @dev This is a permissioned function, unavailable when the pool is paused.
         * The details of the configuration data are set by each Asset Manager. (For an example, see
         * `RewardsAssetManager`.)
         */
        function setAssetManagerPoolConfig(IERC20 token, bytes memory poolConfig)
            public
            virtual
            override
            authenticate
            whenNotPaused
        {
            _setAssetManagerPoolConfig(token, poolConfig);
        }
        function _setAssetManagerPoolConfig(IERC20 token, bytes memory poolConfig) private {
            bytes32 poolId = getPoolId();
            (, , , address assetManager) = getVault().getPoolTokenInfo(poolId, token);
            IAssetManager(assetManager).setConfig(poolId, poolConfig);
        }
        /**
         * @notice Pause the pool: an emergency action which disables all pool functions.
         * @dev This is a permissioned function that will only work during the Pause Window set during pool factory
         * deployment (see `TemporarilyPausable`).
         */
        function pause() external authenticate {
            _setPaused(true);
        }
        /**
         * @notice Reverse a `pause` operation, and restore a pool to normal functionality.
         * @dev This is a permissioned function that will only work on a paused pool within the Buffer Period set during
         * pool factory deployment (see `TemporarilyPausable`). Note that any paused pools will automatically unpause
         * after the Buffer Period expires.
         */
        function unpause() external authenticate {
            _setPaused(false);
        }
        function _isOwnerOnlyAction(bytes32 actionId) internal view virtual override returns (bool) {
            return
                (actionId == getActionId(this.setSwapFeePercentage.selector)) ||
                (actionId == getActionId(this.setAssetManagerPoolConfig.selector));
        }
        function _getMiscData() internal view returns (bytes32) {
            return _miscData;
        }
        /**
         * @dev Inserts data into the least-significant 192 bits of the misc data storage slot.
         * Note that the remaining 64 bits are used for the swap fee percentage and cannot be overloaded.
         */
        function _setMiscData(bytes32 newData) internal {
            _miscData = _miscData.insertBits192(newData, 0);
        }
        // Join / Exit Hooks
        modifier onlyVault(bytes32 poolId) {
            _require(msg.sender == address(getVault()), Errors.CALLER_NOT_VAULT);
            _require(poolId == getPoolId(), Errors.INVALID_POOL_ID);
            _;
        }
        /**
         * @notice Vault hook for adding liquidity to a pool (including the first time, "initializing" the pool).
         * @dev This function can only be called from the Vault, from `joinPool`.
         */
        function onJoinPool(
            bytes32 poolId,
            address sender,
            address recipient,
            uint256[] memory balances,
            uint256 lastChangeBlock,
            uint256 protocolSwapFeePercentage,
            bytes memory userData
        ) external override onlyVault(poolId) returns (uint256[] memory, uint256[] memory) {
            _beforeSwapJoinExit();
            uint256[] memory scalingFactors = _scalingFactors();
            if (totalSupply() == 0) {
                (uint256 bptAmountOut, uint256[] memory amountsIn) = _onInitializePool(
                    poolId,
                    sender,
                    recipient,
                    scalingFactors,
                    userData
                );
                // On initialization, we lock _getMinimumBpt() by minting it for the zero address. This BPT acts as a
                // minimum as it will never be burned, which reduces potential issues with rounding, and also prevents the
                // Pool from ever being fully drained.
                _require(bptAmountOut >= _getMinimumBpt(), Errors.MINIMUM_BPT);
                _mintPoolTokens(address(0), _getMinimumBpt());
                _mintPoolTokens(recipient, bptAmountOut - _getMinimumBpt());
                // amountsIn are amounts entering the Pool, so we round up.
                _downscaleUpArray(amountsIn, scalingFactors);
                return (amountsIn, new uint256[](balances.length));
            } else {
                _upscaleArray(balances, scalingFactors);
                (uint256 bptAmountOut, uint256[] memory amountsIn) = _onJoinPool(
                    poolId,
                    sender,
                    recipient,
                    balances,
                    lastChangeBlock,
                    inRecoveryMode() ? 0 : protocolSwapFeePercentage, // Protocol fees are disabled while in recovery mode
                    scalingFactors,
                    userData
                );
                // Note we no longer use `balances` after calling `_onJoinPool`, which may mutate it.
                _mintPoolTokens(recipient, bptAmountOut);
                // amountsIn are amounts entering the Pool, so we round up.
                _downscaleUpArray(amountsIn, scalingFactors);
                // This Pool ignores the `dueProtocolFees` return value, so we simply return a zeroed-out array.
                return (amountsIn, new uint256[](balances.length));
            }
        }
        /**
         * @notice Vault hook for removing liquidity from a pool.
         * @dev This function can only be called from the Vault, from `exitPool`.
         */
        function onExitPool(
            bytes32 poolId,
            address sender,
            address recipient,
            uint256[] memory balances,
            uint256 lastChangeBlock,
            uint256 protocolSwapFeePercentage,
            bytes memory userData
        ) external override onlyVault(poolId) returns (uint256[] memory, uint256[] memory) {
            uint256[] memory amountsOut;
            uint256 bptAmountIn;
            // When a user calls `exitPool`, this is the first point of entry from the Vault.
            // We first check whether this is a Recovery Mode exit - if so, we proceed using this special lightweight exit
            // mechanism which avoids computing any complex values, interacting with external contracts, etc., and generally
            // should always work, even if the Pool's mathematics or a dependency break down.
            if (userData.isRecoveryModeExitKind()) {
                // This exit kind is only available in Recovery Mode.
                _ensureInRecoveryMode();
                // Note that we don't upscale balances nor downscale amountsOut - we don't care about scaling factors during
                // a recovery mode exit.
                (bptAmountIn, amountsOut) = _doRecoveryModeExit(balances, totalSupply(), userData);
            } else {
                // Note that we only call this if we're not in a recovery mode exit.
                _beforeSwapJoinExit();
                uint256[] memory scalingFactors = _scalingFactors();
                _upscaleArray(balances, scalingFactors);
                (bptAmountIn, amountsOut) = _onExitPool(
                    poolId,
                    sender,
                    recipient,
                    balances,
                    lastChangeBlock,
                    inRecoveryMode() ? 0 : protocolSwapFeePercentage, // Protocol fees are disabled while in recovery mode
                    scalingFactors,
                    userData
                );
                // amountsOut are amounts exiting the Pool, so we round down.
                _downscaleDownArray(amountsOut, scalingFactors);
            }
            // Note we no longer use `balances` after calling `_onExitPool`, which may mutate it.
            _burnPoolTokens(sender, bptAmountIn);
            // This Pool ignores the `dueProtocolFees` return value, so we simply return a zeroed-out array.
            return (amountsOut, new uint256[](balances.length));
        }
        // Query functions
        /**
         * @notice "Dry run" `onJoinPool`.
         * @dev Returns the amount of BPT that would be granted to `recipient` if the `onJoinPool` hook were called by the
         * Vault with the same arguments, along with the number of tokens `sender` would have to supply.
         *
         * This function is not meant to be called directly, but rather from a helper contract that fetches current Vault
         * data, such as the protocol swap fee percentage and Pool balances.
         *
         * Like `IVault.queryBatchSwap`, this function is not view due to internal implementation details: the caller must
         * explicitly use eth_call instead of eth_sendTransaction.
         */
        function queryJoin(
            bytes32 poolId,
            address sender,
            address recipient,
            uint256[] memory balances,
            uint256 lastChangeBlock,
            uint256 protocolSwapFeePercentage,
            bytes memory userData
        ) external override returns (uint256 bptOut, uint256[] memory amountsIn) {
            InputHelpers.ensureInputLengthMatch(balances.length, _getTotalTokens());
            _queryAction(
                poolId,
                sender,
                recipient,
                balances,
                lastChangeBlock,
                protocolSwapFeePercentage,
                userData,
                _onJoinPool,
                _downscaleUpArray
            );
            // The `return` opcode is executed directly inside `_queryAction`, so execution never reaches this statement,
            // and we don't need to return anything here - it just silences compiler warnings.
            return (bptOut, amountsIn);
        }
        /**
         * @notice "Dry run" `onExitPool`.
         * @dev Returns the amount of BPT that would be burned from `sender` if the `onExitPool` hook were called by the
         * Vault with the same arguments, along with the number of tokens `recipient` would receive.
         *
         * This function is not meant to be called directly, but rather from a helper contract that fetches current Vault
         * data, such as the protocol swap fee percentage and Pool balances.
         *
         * Like `IVault.queryBatchSwap`, this function is not view due to internal implementation details: the caller must
         * explicitly use eth_call instead of eth_sendTransaction.
         */
        function queryExit(
            bytes32 poolId,
            address sender,
            address recipient,
            uint256[] memory balances,
            uint256 lastChangeBlock,
            uint256 protocolSwapFeePercentage,
            bytes memory userData
        ) external override returns (uint256 bptIn, uint256[] memory amountsOut) {
            InputHelpers.ensureInputLengthMatch(balances.length, _getTotalTokens());
            _queryAction(
                poolId,
                sender,
                recipient,
                balances,
                lastChangeBlock,
                protocolSwapFeePercentage,
                userData,
                _onExitPool,
                _downscaleDownArray
            );
            // The `return` opcode is executed directly inside `_queryAction`, so execution never reaches this statement,
            // and we don't need to return anything here - it just silences compiler warnings.
            return (bptIn, amountsOut);
        }
        // Internal hooks to be overridden by derived contracts - all token amounts (except BPT) in these interfaces are
        // upscaled.
        /**
         * @dev Called when the Pool is joined for the first time; that is, when the BPT total supply is zero.
         *
         * Returns the amount of BPT to mint, and the token amounts the Pool will receive in return.
         *
         * Minted BPT will be sent to `recipient`, except for _getMinimumBpt(), which will be deducted from this amount and
         * sent to the zero address instead. This will cause that BPT to remain forever locked there, preventing total BTP
         * from ever dropping below that value, and ensuring `_onInitializePool` can only be called once in the entire
         * Pool's lifetime.
         *
         * The tokens granted to the Pool will be transferred from `sender`. These amounts are considered upscaled and will
         * be downscaled (rounding up) before being returned to the Vault.
         */
        function _onInitializePool(
            bytes32 poolId,
            address sender,
            address recipient,
            uint256[] memory scalingFactors,
            bytes memory userData
        ) internal virtual returns (uint256 bptAmountOut, uint256[] memory amountsIn);
        /**
         * @dev Called whenever the Pool is joined after the first initialization join (see `_onInitializePool`).
         *
         * Returns the amount of BPT to mint, the token amounts that the Pool will receive in return, and the number of
         * tokens to pay in protocol swap fees.
         *
         * Implementations of this function might choose to mutate the `balances` array to save gas (e.g. when
         * performing intermediate calculations, such as subtraction of due protocol fees). This can be done safely.
         *
         * Minted BPT will be sent to `recipient`.
         *
         * The tokens granted to the Pool will be transferred from `sender`. These amounts are considered upscaled and will
         * be downscaled (rounding up) before being returned to the Vault.
         *
         * Due protocol swap fees will be taken from the Pool's balance in the Vault (see `IBasePool.onJoinPool`). These
         * amounts are considered upscaled and will be downscaled (rounding down) before being returned to the Vault.
         */
        function _onJoinPool(
            bytes32 poolId,
            address sender,
            address recipient,
            uint256[] memory balances,
            uint256 lastChangeBlock,
            uint256 protocolSwapFeePercentage,
            uint256[] memory scalingFactors,
            bytes memory userData
        ) internal virtual returns (uint256 bptAmountOut, uint256[] memory amountsIn);
        /**
         * @dev Called whenever the Pool is exited.
         *
         * Returns the amount of BPT to burn, the token amounts for each Pool token that the Pool will grant in return, and
         * the number of tokens to pay in protocol swap fees.
         *
         * Implementations of this function might choose to mutate the `balances` array to save gas (e.g. when
         * performing intermediate calculations, such as subtraction of due protocol fees). This can be done safely.
         *
         * BPT will be burnt from `sender`.
         *
         * The Pool will grant tokens to `recipient`. These amounts are considered upscaled and will be downscaled
         * (rounding down) before being returned to the Vault.
         *
         * Due protocol swap fees will be taken from the Pool's balance in the Vault (see `IBasePool.onExitPool`). These
         * amounts are considered upscaled and will be downscaled (rounding down) before being returned to the Vault.
         */
        function _onExitPool(
            bytes32 poolId,
            address sender,
            address recipient,
            uint256[] memory balances,
            uint256 lastChangeBlock,
            uint256 protocolSwapFeePercentage,
            uint256[] memory scalingFactors,
            bytes memory userData
        ) internal virtual returns (uint256 bptAmountIn, uint256[] memory amountsOut);
        /**
         * @dev Called at the very beginning of swaps, joins and exits, even before the scaling factors are read. Derived
         * contracts can extend this implementation to perform any state-changing operations they might need (including e.g.
         * updating the scaling factors),
         *
         * The only scenario in which this function is not called is during a recovery mode exit. This makes it safe to
         * perform non-trivial computations or interact with external dependencies here, as recovery mode will not be
         * affected.
         *
         * Since this contract does not implement swaps, derived contracts must also make sure this function is called on
         * swap handlers.
         */
        function _beforeSwapJoinExit() internal virtual {
            // All joins, exits and swaps are disabled (except recovery mode exits).
            _ensureNotPaused();
        }
        // Internal functions
        /**
         * @dev Pays protocol fees by minting `bptAmount` to the Protocol Fee Collector.
         */
        function _payProtocolFees(uint256 bptAmount) internal {
            _mintPoolTokens(address(getProtocolFeesCollector()), bptAmount);
        }
        /**
         * @dev Adds swap fee amount to `amount`, returning a higher value.
         */
        function _addSwapFeeAmount(uint256 amount) internal view returns (uint256) {
            // This returns amount + fee amount, so we round up (favoring a higher fee amount).
            return amount.divUp(getSwapFeePercentage().complement());
        }
        /**
         * @dev Subtracts swap fee amount from `amount`, returning a lower value.
         */
        function _subtractSwapFeeAmount(uint256 amount) internal view returns (uint256) {
            // This returns amount - fee amount, so we round up (favoring a higher fee amount).
            uint256 feeAmount = amount.mulUp(getSwapFeePercentage());
            return amount.sub(feeAmount);
        }
        // Scaling
        /**
         * @dev Returns a scaling factor that, when multiplied to a token amount for `token`, normalizes its balance as if
         * it had 18 decimals.
         */
        function _computeScalingFactor(IERC20 token) internal view returns (uint256) {
            if (address(token) == address(this)) {
                return FixedPoint.ONE;
            }
            // Tokens that don't implement the `decimals` method are not supported.
            uint256 tokenDecimals = ERC20(address(token)).decimals();
            // Tokens with more than 18 decimals are not supported.
            uint256 decimalsDifference = Math.sub(18, tokenDecimals);
            return FixedPoint.ONE * 10**decimalsDifference;
        }
        /**
         * @dev Returns the scaling factor for one of the Pool's tokens. Reverts if `token` is not a token registered by the
         * Pool.
         *
         * All scaling factors are fixed-point values with 18 decimals, to allow for this function to be overridden by
         * derived contracts that need to apply further scaling, making these factors potentially non-integer.
         *
         * The largest 'base' scaling factor (i.e. in tokens with less than 18 decimals) is 10**18, which in fixed-point is
         * 10**36. This value can be multiplied with a 112 bit Vault balance with no overflow by a factor of ~1e7, making
         * even relatively 'large' factors safe to use.
         *
         * The 1e7 figure is the result of 2**256 / (1e18 * 1e18 * 2**112).
         */
        function _scalingFactor(IERC20 token) internal view virtual returns (uint256);
        /**
         * @dev Same as `_scalingFactor()`, except for all registered tokens (in the same order as registered). The Vault
         * will always pass balances in this order when calling any of the Pool hooks.
         */
        function _scalingFactors() internal view virtual returns (uint256[] memory);
        function getScalingFactors() external view override returns (uint256[] memory) {
            return _scalingFactors();
        }
        /**
         * @dev Applies `scalingFactor` to `amount`, resulting in a larger or equal value depending on whether it needed
         * scaling or not.
         */
        function _upscale(uint256 amount, uint256 scalingFactor) internal pure returns (uint256) {
            // Upscale rounding wouldn't necessarily always go in the same direction: in a swap for example the balance of
            // token in should be rounded up, and that of token out rounded down. This is the only place where we round in
            // the same direction for all amounts, as the impact of this rounding is expected to be minimal (and there's no
            // rounding error unless `_scalingFactor()` is overriden).
            return FixedPoint.mulDown(amount, scalingFactor);
        }
        /**
         * @dev Same as `_upscale`, but for an entire array. This function does not return anything, but instead *mutates*
         * the `amounts` array.
         */
        function _upscaleArray(uint256[] memory amounts, uint256[] memory scalingFactors) internal pure {
            uint256 length = amounts.length;
            InputHelpers.ensureInputLengthMatch(length, scalingFactors.length);
            for (uint256 i = 0; i < length; ++i) {
                amounts[i] = FixedPoint.mulDown(amounts[i], scalingFactors[i]);
            }
        }
        /**
         * @dev Reverses the `scalingFactor` applied to `amount`, resulting in a smaller or equal value depending on
         * whether it needed scaling or not. The result is rounded down.
         */
        function _downscaleDown(uint256 amount, uint256 scalingFactor) internal pure returns (uint256) {
            return FixedPoint.divDown(amount, scalingFactor);
        }
        /**
         * @dev Same as `_downscaleDown`, but for an entire array. This function does not return anything, but instead
         * *mutates* the `amounts` array.
         */
        function _downscaleDownArray(uint256[] memory amounts, uint256[] memory scalingFactors) internal pure {
            uint256 length = amounts.length;
            InputHelpers.ensureInputLengthMatch(length, scalingFactors.length);
            for (uint256 i = 0; i < length; ++i) {
                amounts[i] = FixedPoint.divDown(amounts[i], scalingFactors[i]);
            }
        }
        /**
         * @dev Reverses the `scalingFactor` applied to `amount`, resulting in a smaller or equal value depending on
         * whether it needed scaling or not. The result is rounded up.
         */
        function _downscaleUp(uint256 amount, uint256 scalingFactor) internal pure returns (uint256) {
            return FixedPoint.divUp(amount, scalingFactor);
        }
        /**
         * @dev Same as `_downscaleUp`, but for an entire array. This function does not return anything, but instead
         * *mutates* the `amounts` array.
         */
        function _downscaleUpArray(uint256[] memory amounts, uint256[] memory scalingFactors) internal pure {
            uint256 length = amounts.length;
            InputHelpers.ensureInputLengthMatch(length, scalingFactors.length);
            for (uint256 i = 0; i < length; ++i) {
                amounts[i] = FixedPoint.divUp(amounts[i], scalingFactors[i]);
            }
        }
        function _getAuthorizer() internal view override returns (IAuthorizer) {
            // Access control management is delegated to the Vault's Authorizer. This lets Balancer Governance manage which
            // accounts can call permissioned functions: for example, to perform emergency pauses.
            // If the owner is delegated, then *all* permissioned functions, including `setSwapFeePercentage`, will be under
            // Governance control.
            return getVault().getAuthorizer();
        }
        function _queryAction(
            bytes32 poolId,
            address sender,
            address recipient,
            uint256[] memory balances,
            uint256 lastChangeBlock,
            uint256 protocolSwapFeePercentage,
            bytes memory userData,
            function(bytes32, address, address, uint256[] memory, uint256, uint256, uint256[] memory, bytes memory)
                internal
                returns (uint256, uint256[] memory) _action,
            function(uint256[] memory, uint256[] memory) internal view _downscaleArray
        ) private {
            // This uses the same technique used by the Vault in queryBatchSwap. Refer to that function for a detailed
            // explanation.
            if (msg.sender != address(this)) {
                // We perform an external call to ourselves, forwarding the same calldata. In this call, the else clause of
                // the preceding if statement will be executed instead.
                // solhint-disable-next-line avoid-low-level-calls
                (bool success, ) = address(this).call(msg.data);
                // solhint-disable-next-line no-inline-assembly
                assembly {
                    // This call should always revert to decode the bpt and token amounts from the revert reason
                    switch success
                        case 0 {
                            // Note we are manually writing the memory slot 0. We can safely overwrite whatever is
                            // stored there as we take full control of the execution and then immediately return.
                            // We copy the first 4 bytes to check if it matches with the expected signature, otherwise
                            // there was another revert reason and we should forward it.
                            returndatacopy(0, 0, 0x04)
                            let error := and(mload(0), 0xffffffff00000000000000000000000000000000000000000000000000000000)
                            // If the first 4 bytes don't match with the expected signature, we forward the revert reason.
                            if eq(eq(error, 0x43adbafb00000000000000000000000000000000000000000000000000000000), 0) {
                                returndatacopy(0, 0, returndatasize())
                                revert(0, returndatasize())
                            }
                            // The returndata contains the signature, followed by the raw memory representation of the
                            // `bptAmount` and `tokenAmounts` (array: length + data). We need to return an ABI-encoded
                            // representation of these.
                            // An ABI-encoded response will include one additional field to indicate the starting offset of
                            // the `tokenAmounts` array. The `bptAmount` will be laid out in the first word of the
                            // returndata.
                            //
                            // In returndata:
                            // [ signature ][ bptAmount ][ tokenAmounts length ][ tokenAmounts values ]
                            // [  4 bytes  ][  32 bytes ][       32 bytes      ][ (32 * length) bytes ]
                            //
                            // We now need to return (ABI-encoded values):
                            // [ bptAmount ][ tokeAmounts offset ][ tokenAmounts length ][ tokenAmounts values ]
                            // [  32 bytes ][       32 bytes     ][       32 bytes      ][ (32 * length) bytes ]
                            // We copy 32 bytes for the `bptAmount` from returndata into memory.
                            // Note that we skip the first 4 bytes for the error signature
                            returndatacopy(0, 0x04, 32)
                            // The offsets are 32-bytes long, so the array of `tokenAmounts` will start after
                            // the initial 64 bytes.
                            mstore(0x20, 64)
                            // We now copy the raw memory array for the `tokenAmounts` from returndata into memory.
                            // Since bpt amount and offset take up 64 bytes, we start copying at address 0x40. We also
                            // skip the first 36 bytes from returndata, which correspond to the signature plus bpt amount.
                            returndatacopy(0x40, 0x24, sub(returndatasize(), 36))
                            // We finally return the ABI-encoded uint256 and the array, which has a total length equal to
                            // the size of returndata, plus the 32 bytes of the offset but without the 4 bytes of the
                            // error signature.
                            return(0, add(returndatasize(), 28))
                        }
                        default {
                            // This call should always revert, but we fail nonetheless if that didn't happen
                            invalid()
                        }
                }
            } else {
                // This imitates the relevant parts of the bodies of onJoin and onExit. Since they're not virtual, we know
                // that their implementations will match this regardless of what derived contracts might do.
                _beforeSwapJoinExit();
                uint256[] memory scalingFactors = _scalingFactors();
                _upscaleArray(balances, scalingFactors);
                (uint256 bptAmount, uint256[] memory tokenAmounts) = _action(
                    poolId,
                    sender,
                    recipient,
                    balances,
                    lastChangeBlock,
                    protocolSwapFeePercentage,
                    scalingFactors,
                    userData
                );
                _downscaleArray(tokenAmounts, scalingFactors);
                // solhint-disable-next-line no-inline-assembly
                assembly {
                    // We will return a raw representation of `bptAmount` and `tokenAmounts` in memory, which is composed of
                    // a 32-byte uint256, followed by a 32-byte for the array length, and finally the 32-byte uint256 values
                    // Because revert expects a size in bytes, we multiply the array length (stored at `tokenAmounts`) by 32
                    let size := mul(mload(tokenAmounts), 32)
                    // We store the `bptAmount` in the previous slot to the `tokenAmounts` array. We can make sure there
                    // will be at least one available slot due to how the memory scratch space works.
                    // We can safely overwrite whatever is stored in this slot as we will revert immediately after that.
                    let start := sub(tokenAmounts, 0x20)
                    mstore(start, bptAmount)
                    // We send one extra value for the error signature "QueryError(uint256,uint256[])" which is 0x43adbafb
                    // We use the previous slot to `bptAmount`.
                    mstore(sub(start, 0x20), 0x0000000000000000000000000000000000000000000000000000000043adbafb)
                    start := sub(start, 0x04)
                    // When copying from `tokenAmounts` into returndata, we copy the additional 68 bytes to also return
                    // the `bptAmount`, the array 's length, and the error signature.
                    revert(start, add(size, 68))
                }
            }
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "./IVault.sol";
    import "./IPoolSwapStructs.sol";
    /**
     * @dev Interface for adding and removing liquidity that all Pool contracts should implement. Note that this is not
     * the complete Pool contract interface, as it is missing the swap hooks. Pool contracts should also inherit from
     * either IGeneralPool or IMinimalSwapInfoPool
     */
    interface IBasePool is IPoolSwapStructs {
        /**
         * @dev Called by the Vault when a user calls `IVault.joinPool` to add liquidity to this Pool. Returns how many of
         * each registered token the user should provide, as well as the amount of protocol fees the Pool owes to the Vault.
         * The Vault will then take tokens from `sender` and add them to the Pool's balances, as well as collect
         * the reported amount in protocol fees, which the pool should calculate based on `protocolSwapFeePercentage`.
         *
         * Protocol fees are reported and charged on join events so that the Pool is free of debt whenever new users join.
         *
         * `sender` is the account performing the join (from which tokens will be withdrawn), and `recipient` is the account
         * designated to receive any benefits (typically pool shares). `balances` contains the total balances
         * for each token the Pool registered in the Vault, in the same order that `IVault.getPoolTokens` would return.
         *
         * `lastChangeBlock` is the last block in which *any* of the Pool's registered tokens last changed its total
         * balance.
         *
         * `userData` contains any pool-specific instructions needed to perform the calculations, such as the type of
         * join (e.g., proportional given an amount of pool shares, single-asset, multi-asset, etc.)
         *
         * Contracts implementing this function should check that the caller is indeed the Vault before performing any
         * state-changing operations, such as minting pool shares.
         */
        function onJoinPool(
            bytes32 poolId,
            address sender,
            address recipient,
            uint256[] memory balances,
            uint256 lastChangeBlock,
            uint256 protocolSwapFeePercentage,
            bytes memory userData
        ) external returns (uint256[] memory amountsIn, uint256[] memory dueProtocolFeeAmounts);
        /**
         * @dev Called by the Vault when a user calls `IVault.exitPool` to remove liquidity from this Pool. Returns how many
         * tokens the Vault should deduct from the Pool's balances, as well as the amount of protocol fees the Pool owes
         * to the Vault. The Vault will then take tokens from the Pool's balances and send them to `recipient`,
         * as well as collect the reported amount in protocol fees, which the Pool should calculate based on
         * `protocolSwapFeePercentage`.
         *
         * Protocol fees are charged on exit events to guarantee that users exiting the Pool have paid their share.
         *
         * `sender` is the account performing the exit (typically the pool shareholder), and `recipient` is the account
         * to which the Vault will send the proceeds. `balances` contains the total token balances for each token
         * the Pool registered in the Vault, in the same order that `IVault.getPoolTokens` would return.
         *
         * `lastChangeBlock` is the last block in which *any* of the Pool's registered tokens last changed its total
         * balance.
         *
         * `userData` contains any pool-specific instructions needed to perform the calculations, such as the type of
         * exit (e.g., proportional given an amount of pool shares, single-asset, multi-asset, etc.)
         *
         * Contracts implementing this function should check that the caller is indeed the Vault before performing any
         * state-changing operations, such as burning pool shares.
         */
        function onExitPool(
            bytes32 poolId,
            address sender,
            address recipient,
            uint256[] memory balances,
            uint256 lastChangeBlock,
            uint256 protocolSwapFeePercentage,
            bytes memory userData
        ) external returns (uint256[] memory amountsOut, uint256[] memory dueProtocolFeeAmounts);
        /**
         * @dev Returns this Pool's ID, used when interacting with the Vault (to e.g. join the Pool or swap with it).
         */
        function getPoolId() external view returns (bytes32);
        /**
         * @dev Returns the current swap fee percentage as a 18 decimal fixed point number, so e.g. 1e17 corresponds to a
         * 10% swap fee.
         */
        function getSwapFeePercentage() external view returns (uint256);
        /**
         * @dev Returns the scaling factors of each of the Pool's tokens. This is an implementation detail that is typically
         * not relevant for outside parties, but which might be useful for some types of Pools.
         */
        function getScalingFactors() external view returns (uint256[] memory);
        function queryJoin(
            bytes32 poolId,
            address sender,
            address recipient,
            uint256[] memory balances,
            uint256 lastChangeBlock,
            uint256 protocolSwapFeePercentage,
            bytes memory userData
        ) external returns (uint256 bptOut, uint256[] memory amountsIn);
        function queryExit(
            bytes32 poolId,
            address sender,
            address recipient,
            uint256[] memory balances,
            uint256 lastChangeBlock,
            uint256 protocolSwapFeePercentage,
            bytes memory userData
        ) external returns (uint256 bptIn, uint256[] memory amountsOut);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma experimental ABIEncoderV2;
    import "../solidity-utils/openzeppelin/IERC20.sol";
    import "../solidity-utils/helpers/IAuthentication.sol";
    import "../solidity-utils/helpers/ISignaturesValidator.sol";
    import "../solidity-utils/helpers/ITemporarilyPausable.sol";
    import "../solidity-utils/misc/IWETH.sol";
    import "./IAsset.sol";
    import "./IAuthorizer.sol";
    import "./IFlashLoanRecipient.sol";
    import "./IProtocolFeesCollector.sol";
    pragma solidity ^0.7.0;
    /**
     * @dev Full external interface for the Vault core contract - no external or public methods exist in the contract that
     * don't override one of these declarations.
     */
    interface IVault is ISignaturesValidator, ITemporarilyPausable, IAuthentication {
        // Generalities about the Vault:
        //
        // - Whenever documentation refers to 'tokens', it strictly refers to ERC20-compliant token contracts. Tokens are
        // transferred out of the Vault by calling the `IERC20.transfer` function, and transferred in by calling
        // `IERC20.transferFrom`. In these cases, the sender must have previously allowed the Vault to use their tokens by
        // calling `IERC20.approve`. The only deviation from the ERC20 standard that is supported is functions not returning
        // a boolean value: in these scenarios, a non-reverting call is assumed to be successful.
        //
        // - All non-view functions in the Vault are non-reentrant: calling them while another one is mid-execution (e.g.
        // while execution control is transferred to a token contract during a swap) will result in a revert. View
        // functions can be called in a re-reentrant way, but doing so might cause them to return inconsistent results.
        // Contracts calling view functions in the Vault must make sure the Vault has not already been entered.
        //
        // - View functions revert if referring to either unregistered Pools, or unregistered tokens for registered Pools.
        // Authorizer
        //
        // Some system actions are permissioned, like setting and collecting protocol fees. This permissioning system exists
        // outside of the Vault in the Authorizer contract: the Vault simply calls the Authorizer to check if the caller
        // can perform a given action.
        /**
         * @dev Returns the Vault's Authorizer.
         */
        function getAuthorizer() external view returns (IAuthorizer);
        /**
         * @dev Sets a new Authorizer for the Vault. The caller must be allowed by the current Authorizer to do this.
         *
         * Emits an `AuthorizerChanged` event.
         */
        function setAuthorizer(IAuthorizer newAuthorizer) external;
        /**
         * @dev Emitted when a new authorizer is set by `setAuthorizer`.
         */
        event AuthorizerChanged(IAuthorizer indexed newAuthorizer);
        // Relayers
        //
        // Additionally, it is possible for an account to perform certain actions on behalf of another one, using their
        // Vault ERC20 allowance and Internal Balance. These accounts are said to be 'relayers' for these Vault functions,
        // and are expected to be smart contracts with sound authentication mechanisms. For an account to be able to wield
        // this power, two things must occur:
        //  - The Authorizer must grant the account the permission to be a relayer for the relevant Vault function. This
        //    means that Balancer governance must approve each individual contract to act as a relayer for the intended
        //    functions.
        //  - Each user must approve the relayer to act on their behalf.
        // This double protection means users cannot be tricked into approving malicious relayers (because they will not
        // have been allowed by the Authorizer via governance), nor can malicious relayers approved by a compromised
        // Authorizer or governance drain user funds, since they would also need to be approved by each individual user.
        /**
         * @dev Returns true if `user` has approved `relayer` to act as a relayer for them.
         */
        function hasApprovedRelayer(address user, address relayer) external view returns (bool);
        /**
         * @dev Allows `relayer` to act as a relayer for `sender` if `approved` is true, and disallows it otherwise.
         *
         * Emits a `RelayerApprovalChanged` event.
         */
        function setRelayerApproval(
            address sender,
            address relayer,
            bool approved
        ) external;
        /**
         * @dev Emitted every time a relayer is approved or disapproved by `setRelayerApproval`.
         */
        event RelayerApprovalChanged(address indexed relayer, address indexed sender, bool approved);
        // Internal Balance
        //
        // Users can deposit tokens into the Vault, where they are allocated to their Internal Balance, and later
        // transferred or withdrawn. It can also be used as a source of tokens when joining Pools, as a destination
        // when exiting them, and as either when performing swaps. This usage of Internal Balance results in greatly reduced
        // gas costs when compared to relying on plain ERC20 transfers, leading to large savings for frequent users.
        //
        // Internal Balance management features batching, which means a single contract call can be used to perform multiple
        // operations of different kinds, with different senders and recipients, at once.
        /**
         * @dev Returns `user`'s Internal Balance for a set of tokens.
         */
        function getInternalBalance(address user, IERC20[] memory tokens) external view returns (uint256[] memory);
        /**
         * @dev Performs a set of user balance operations, which involve Internal Balance (deposit, withdraw or transfer)
         * and plain ERC20 transfers using the Vault's allowance. This last feature is particularly useful for relayers, as
         * it lets integrators reuse a user's Vault allowance.
         *
         * For each operation, if the caller is not `sender`, it must be an authorized relayer for them.
         */
        function manageUserBalance(UserBalanceOp[] memory ops) external payable;
        /**
         * @dev Data for `manageUserBalance` operations, which include the possibility for ETH to be sent and received
         without manual WETH wrapping or unwrapping.
         */
        struct UserBalanceOp {
            UserBalanceOpKind kind;
            IAsset asset;
            uint256 amount;
            address sender;
            address payable recipient;
        }
        // There are four possible operations in `manageUserBalance`:
        //
        // - DEPOSIT_INTERNAL
        // Increases the Internal Balance of the `recipient` account by transferring tokens from the corresponding
        // `sender`. The sender must have allowed the Vault to use their tokens via `IERC20.approve()`.
        //
        // ETH can be used by passing the ETH sentinel value as the asset and forwarding ETH in the call: it will be wrapped
        // and deposited as WETH. Any ETH amount remaining will be sent back to the caller (not the sender, which is
        // relevant for relayers).
        //
        // Emits an `InternalBalanceChanged` event.
        //
        //
        // - WITHDRAW_INTERNAL
        // Decreases the Internal Balance of the `sender` account by transferring tokens to the `recipient`.
        //
        // ETH can be used by passing the ETH sentinel value as the asset. This will deduct WETH instead, unwrap it and send
        // it to the recipient as ETH.
        //
        // Emits an `InternalBalanceChanged` event.
        //
        //
        // - TRANSFER_INTERNAL
        // Transfers tokens from the Internal Balance of the `sender` account to the Internal Balance of `recipient`.
        //
        // Reverts if the ETH sentinel value is passed.
        //
        // Emits an `InternalBalanceChanged` event.
        //
        //
        // - TRANSFER_EXTERNAL
        // Transfers tokens from `sender` to `recipient`, using the Vault's ERC20 allowance. This is typically used by
        // relayers, as it lets them reuse a user's Vault allowance.
        //
        // Reverts if the ETH sentinel value is passed.
        //
        // Emits an `ExternalBalanceTransfer` event.
        enum UserBalanceOpKind { DEPOSIT_INTERNAL, WITHDRAW_INTERNAL, TRANSFER_INTERNAL, TRANSFER_EXTERNAL }
        /**
         * @dev Emitted when a user's Internal Balance changes, either from calls to `manageUserBalance`, or through
         * interacting with Pools using Internal Balance.
         *
         * Because Internal Balance works exclusively with ERC20 tokens, ETH deposits and withdrawals will use the WETH
         * address.
         */
        event InternalBalanceChanged(address indexed user, IERC20 indexed token, int256 delta);
        /**
         * @dev Emitted when a user's Vault ERC20 allowance is used by the Vault to transfer tokens to an external account.
         */
        event ExternalBalanceTransfer(IERC20 indexed token, address indexed sender, address recipient, uint256 amount);
        // Pools
        //
        // There are three specialization settings for Pools, which allow for cheaper swaps at the cost of reduced
        // functionality:
        //
        //  - General: no specialization, suited for all Pools. IGeneralPool is used for swap request callbacks, passing the
        // balance of all tokens in the Pool. These Pools have the largest swap costs (because of the extra storage reads),
        // which increase with the number of registered tokens.
        //
        //  - Minimal Swap Info: IMinimalSwapInfoPool is used instead of IGeneralPool, which saves gas by only passing the
        // balance of the two tokens involved in the swap. This is suitable for some pricing algorithms, like the weighted
        // constant product one popularized by Balancer V1. Swap costs are smaller compared to general Pools, and are
        // independent of the number of registered tokens.
        //
        //  - Two Token: only allows two tokens to be registered. This achieves the lowest possible swap gas cost. Like
        // minimal swap info Pools, these are called via IMinimalSwapInfoPool.
        enum PoolSpecialization { GENERAL, MINIMAL_SWAP_INFO, TWO_TOKEN }
        /**
         * @dev Registers the caller account as a Pool with a given specialization setting. Returns the Pool's ID, which
         * is used in all Pool-related functions. Pools cannot be deregistered, nor can the Pool's specialization be
         * changed.
         *
         * The caller is expected to be a smart contract that implements either `IGeneralPool` or `IMinimalSwapInfoPool`,
         * depending on the chosen specialization setting. This contract is known as the Pool's contract.
         *
         * Note that the same contract may register itself as multiple Pools with unique Pool IDs, or in other words,
         * multiple Pools may share the same contract.
         *
         * Emits a `PoolRegistered` event.
         */
        function registerPool(PoolSpecialization specialization) external returns (bytes32);
        /**
         * @dev Emitted when a Pool is registered by calling `registerPool`.
         */
        event PoolRegistered(bytes32 indexed poolId, address indexed poolAddress, PoolSpecialization specialization);
        /**
         * @dev Returns a Pool's contract address and specialization setting.
         */
        function getPool(bytes32 poolId) external view returns (address, PoolSpecialization);
        /**
         * @dev Registers `tokens` for the `poolId` Pool. Must be called by the Pool's contract.
         *
         * Pools can only interact with tokens they have registered. Users join a Pool by transferring registered tokens,
         * exit by receiving registered tokens, and can only swap registered tokens.
         *
         * Each token can only be registered once. For Pools with the Two Token specialization, `tokens` must have a length
         * of two, that is, both tokens must be registered in the same `registerTokens` call, and they must be sorted in
         * ascending order.
         *
         * The `tokens` and `assetManagers` arrays must have the same length, and each entry in these indicates the Asset
         * Manager for the corresponding token. Asset Managers can manage a Pool's tokens via `managePoolBalance`,
         * depositing and withdrawing them directly, and can even set their balance to arbitrary amounts. They are therefore
         * expected to be highly secured smart contracts with sound design principles, and the decision to register an
         * Asset Manager should not be made lightly.
         *
         * Pools can choose not to assign an Asset Manager to a given token by passing in the zero address. Once an Asset
         * Manager is set, it cannot be changed except by deregistering the associated token and registering again with a
         * different Asset Manager.
         *
         * Emits a `TokensRegistered` event.
         */
        function registerTokens(
            bytes32 poolId,
            IERC20[] memory tokens,
            address[] memory assetManagers
        ) external;
        /**
         * @dev Emitted when a Pool registers tokens by calling `registerTokens`.
         */
        event TokensRegistered(bytes32 indexed poolId, IERC20[] tokens, address[] assetManagers);
        /**
         * @dev Deregisters `tokens` for the `poolId` Pool. Must be called by the Pool's contract.
         *
         * Only registered tokens (via `registerTokens`) can be deregistered. Additionally, they must have zero total
         * balance. For Pools with the Two Token specialization, `tokens` must have a length of two, that is, both tokens
         * must be deregistered in the same `deregisterTokens` call.
         *
         * A deregistered token can be re-registered later on, possibly with a different Asset Manager.
         *
         * Emits a `TokensDeregistered` event.
         */
        function deregisterTokens(bytes32 poolId, IERC20[] memory tokens) external;
        /**
         * @dev Emitted when a Pool deregisters tokens by calling `deregisterTokens`.
         */
        event TokensDeregistered(bytes32 indexed poolId, IERC20[] tokens);
        /**
         * @dev Returns detailed information for a Pool's registered token.
         *
         * `cash` is the number of tokens the Vault currently holds for the Pool. `managed` is the number of tokens
         * withdrawn and held outside the Vault by the Pool's token Asset Manager. The Pool's total balance for `token`
         * equals the sum of `cash` and `managed`.
         *
         * Internally, `cash` and `managed` are stored using 112 bits. No action can ever cause a Pool's token `cash`,
         * `managed` or `total` balance to be greater than 2^112 - 1.
         *
         * `lastChangeBlock` is the number of the block in which `token`'s total balance was last modified (via either a
         * join, exit, swap, or Asset Manager update). This value is useful to avoid so-called 'sandwich attacks', for
         * example when developing price oracles. A change of zero (e.g. caused by a swap with amount zero) is considered a
         * change for this purpose, and will update `lastChangeBlock`.
         *
         * `assetManager` is the Pool's token Asset Manager.
         */
        function getPoolTokenInfo(bytes32 poolId, IERC20 token)
            external
            view
            returns (
                uint256 cash,
                uint256 managed,
                uint256 lastChangeBlock,
                address assetManager
            );
        /**
         * @dev Returns a Pool's registered tokens, the total balance for each, and the latest block when *any* of
         * the tokens' `balances` changed.
         *
         * The order of the `tokens` array is the same order that will be used in `joinPool`, `exitPool`, as well as in all
         * Pool hooks (where applicable). Calls to `registerTokens` and `deregisterTokens` may change this order.
         *
         * If a Pool only registers tokens once, and these are sorted in ascending order, they will be stored in the same
         * order as passed to `registerTokens`.
         *
         * Total balances include both tokens held by the Vault and those withdrawn by the Pool's Asset Managers. These are
         * the amounts used by joins, exits and swaps. For a detailed breakdown of token balances, use `getPoolTokenInfo`
         * instead.
         */
        function getPoolTokens(bytes32 poolId)
            external
            view
            returns (
                IERC20[] memory tokens,
                uint256[] memory balances,
                uint256 lastChangeBlock
            );
        /**
         * @dev Called by users to join a Pool, which transfers tokens from `sender` into the Pool's balance. This will
         * trigger custom Pool behavior, which will typically grant something in return to `recipient` - often tokenized
         * Pool shares.
         *
         * If the caller is not `sender`, it must be an authorized relayer for them.
         *
         * The `assets` and `maxAmountsIn` arrays must have the same length, and each entry indicates the maximum amount
         * to send for each asset. The amounts to send are decided by the Pool and not the Vault: it just enforces
         * these maximums.
         *
         * If joining a Pool that holds WETH, it is possible to send ETH directly: the Vault will do the wrapping. To enable
         * this mechanism, the IAsset sentinel value (the zero address) must be passed in the `assets` array instead of the
         * WETH address. Note that it is not possible to combine ETH and WETH in the same join. Any excess ETH will be sent
         * back to the caller (not the sender, which is important for relayers).
         *
         * `assets` must have the same length and order as the array returned by `getPoolTokens`. This prevents issues when
         * interacting with Pools that register and deregister tokens frequently. If sending ETH however, the array must be
         * sorted *before* replacing the WETH address with the ETH sentinel value (the zero address), which means the final
         * `assets` array might not be sorted. Pools with no registered tokens cannot be joined.
         *
         * If `fromInternalBalance` is true, the caller's Internal Balance will be preferred: ERC20 transfers will only
         * be made for the difference between the requested amount and Internal Balance (if any). Note that ETH cannot be
         * withdrawn from Internal Balance: attempting to do so will trigger a revert.
         *
         * This causes the Vault to call the `IBasePool.onJoinPool` hook on the Pool's contract, where Pools implement
         * their own custom logic. This typically requires additional information from the user (such as the expected number
         * of Pool shares). This can be encoded in the `userData` argument, which is ignored by the Vault and passed
         * directly to the Pool's contract, as is `recipient`.
         *
         * Emits a `PoolBalanceChanged` event.
         */
        function joinPool(
            bytes32 poolId,
            address sender,
            address recipient,
            JoinPoolRequest memory request
        ) external payable;
        struct JoinPoolRequest {
            IAsset[] assets;
            uint256[] maxAmountsIn;
            bytes userData;
            bool fromInternalBalance;
        }
        /**
         * @dev Called by users to exit a Pool, which transfers tokens from the Pool's balance to `recipient`. This will
         * trigger custom Pool behavior, which will typically ask for something in return from `sender` - often tokenized
         * Pool shares. The amount of tokens that can be withdrawn is limited by the Pool's `cash` balance (see
         * `getPoolTokenInfo`).
         *
         * If the caller is not `sender`, it must be an authorized relayer for them.
         *
         * The `tokens` and `minAmountsOut` arrays must have the same length, and each entry in these indicates the minimum
         * token amount to receive for each token contract. The amounts to send are decided by the Pool and not the Vault:
         * it just enforces these minimums.
         *
         * If exiting a Pool that holds WETH, it is possible to receive ETH directly: the Vault will do the unwrapping. To
         * enable this mechanism, the IAsset sentinel value (the zero address) must be passed in the `assets` array instead
         * of the WETH address. Note that it is not possible to combine ETH and WETH in the same exit.
         *
         * `assets` must have the same length and order as the array returned by `getPoolTokens`. This prevents issues when
         * interacting with Pools that register and deregister tokens frequently. If receiving ETH however, the array must
         * be sorted *before* replacing the WETH address with the ETH sentinel value (the zero address), which means the
         * final `assets` array might not be sorted. Pools with no registered tokens cannot be exited.
         *
         * If `toInternalBalance` is true, the tokens will be deposited to `recipient`'s Internal Balance. Otherwise,
         * an ERC20 transfer will be performed. Note that ETH cannot be deposited to Internal Balance: attempting to
         * do so will trigger a revert.
         *
         * `minAmountsOut` is the minimum amount of tokens the user expects to get out of the Pool, for each token in the
         * `tokens` array. This array must match the Pool's registered tokens.
         *
         * This causes the Vault to call the `IBasePool.onExitPool` hook on the Pool's contract, where Pools implement
         * their own custom logic. This typically requires additional information from the user (such as the expected number
         * of Pool shares to return). This can be encoded in the `userData` argument, which is ignored by the Vault and
         * passed directly to the Pool's contract.
         *
         * Emits a `PoolBalanceChanged` event.
         */
        function exitPool(
            bytes32 poolId,
            address sender,
            address payable recipient,
            ExitPoolRequest memory request
        ) external;
        struct ExitPoolRequest {
            IAsset[] assets;
            uint256[] minAmountsOut;
            bytes userData;
            bool toInternalBalance;
        }
        /**
         * @dev Emitted when a user joins or exits a Pool by calling `joinPool` or `exitPool`, respectively.
         */
        event PoolBalanceChanged(
            bytes32 indexed poolId,
            address indexed liquidityProvider,
            IERC20[] tokens,
            int256[] deltas,
            uint256[] protocolFeeAmounts
        );
        enum PoolBalanceChangeKind { JOIN, EXIT }
        // Swaps
        //
        // Users can swap tokens with Pools by calling the `swap` and `batchSwap` functions. To do this,
        // they need not trust Pool contracts in any way: all security checks are made by the Vault. They must however be
        // aware of the Pools' pricing algorithms in order to estimate the prices Pools will quote.
        //
        // The `swap` function executes a single swap, while `batchSwap` can perform multiple swaps in sequence.
        // In each individual swap, tokens of one kind are sent from the sender to the Pool (this is the 'token in'),
        // and tokens of another kind are sent from the Pool to the recipient in exchange (this is the 'token out').
        // More complex swaps, such as one token in to multiple tokens out can be achieved by batching together
        // individual swaps.
        //
        // There are two swap kinds:
        //  - 'given in' swaps, where the amount of tokens in (sent to the Pool) is known, and the Pool determines (via the
        // `onSwap` hook) the amount of tokens out (to send to the recipient).
        //  - 'given out' swaps, where the amount of tokens out (received from the Pool) is known, and the Pool determines
        // (via the `onSwap` hook) the amount of tokens in (to receive from the sender).
        //
        // Additionally, it is possible to chain swaps using a placeholder input amount, which the Vault replaces with
        // the calculated output of the previous swap. If the previous swap was 'given in', this will be the calculated
        // tokenOut amount. If the previous swap was 'given out', it will use the calculated tokenIn amount. These extended
        // swaps are known as 'multihop' swaps, since they 'hop' through a number of intermediate tokens before arriving at
        // the final intended token.
        //
        // In all cases, tokens are only transferred in and out of the Vault (or withdrawn from and deposited into Internal
        // Balance) after all individual swaps have been completed, and the net token balance change computed. This makes
        // certain swap patterns, such as multihops, or swaps that interact with the same token pair in multiple Pools, cost
        // much less gas than they would otherwise.
        //
        // It also means that under certain conditions it is possible to perform arbitrage by swapping with multiple
        // Pools in a way that results in net token movement out of the Vault (profit), with no tokens being sent in (only
        // updating the Pool's internal accounting).
        //
        // To protect users from front-running or the market changing rapidly, they supply a list of 'limits' for each token
        // involved in the swap, where either the maximum number of tokens to send (by passing a positive value) or the
        // minimum amount of tokens to receive (by passing a negative value) is specified.
        //
        // Additionally, a 'deadline' timestamp can also be provided, forcing the swap to fail if it occurs after
        // this point in time (e.g. if the transaction failed to be included in a block promptly).
        //
        // If interacting with Pools that hold WETH, it is possible to both send and receive ETH directly: the Vault will do
        // the wrapping and unwrapping. To enable this mechanism, the IAsset sentinel value (the zero address) must be
        // passed in the `assets` array instead of the WETH address. Note that it is possible to combine ETH and WETH in the
        // same swap. Any excess ETH will be sent back to the caller (not the sender, which is relevant for relayers).
        //
        // Finally, Internal Balance can be used when either sending or receiving tokens.
        enum SwapKind { GIVEN_IN, GIVEN_OUT }
        /**
         * @dev Performs a swap with a single Pool.
         *
         * If the swap is 'given in' (the number of tokens to send to the Pool is known), it returns the amount of tokens
         * taken from the Pool, which must be greater than or equal to `limit`.
         *
         * If the swap is 'given out' (the number of tokens to take from the Pool is known), it returns the amount of tokens
         * sent to the Pool, which must be less than or equal to `limit`.
         *
         * Internal Balance usage and the recipient are determined by the `funds` struct.
         *
         * Emits a `Swap` event.
         */
        function swap(
            SingleSwap memory singleSwap,
            FundManagement memory funds,
            uint256 limit,
            uint256 deadline
        ) external payable returns (uint256);
        /**
         * @dev Data for a single swap executed by `swap`. `amount` is either `amountIn` or `amountOut` depending on
         * the `kind` value.
         *
         * `assetIn` and `assetOut` are either token addresses, or the IAsset sentinel value for ETH (the zero address).
         * Note that Pools never interact with ETH directly: it will be wrapped to or unwrapped from WETH by the Vault.
         *
         * The `userData` field is ignored by the Vault, but forwarded to the Pool in the `onSwap` hook, and may be
         * used to extend swap behavior.
         */
        struct SingleSwap {
            bytes32 poolId;
            SwapKind kind;
            IAsset assetIn;
            IAsset assetOut;
            uint256 amount;
            bytes userData;
        }
        /**
         * @dev Performs a series of swaps with one or multiple Pools. In each individual swap, the caller determines either
         * the amount of tokens sent to or received from the Pool, depending on the `kind` value.
         *
         * Returns an array with the net Vault asset balance deltas. Positive amounts represent tokens (or ETH) sent to the
         * Vault, and negative amounts represent tokens (or ETH) sent by the Vault. Each delta corresponds to the asset at
         * the same index in the `assets` array.
         *
         * Swaps are executed sequentially, in the order specified by the `swaps` array. Each array element describes a
         * Pool, the token to be sent to this Pool, the token to receive from it, and an amount that is either `amountIn` or
         * `amountOut` depending on the swap kind.
         *
         * Multihop swaps can be executed by passing an `amount` value of zero for a swap. This will cause the amount in/out
         * of the previous swap to be used as the amount in for the current one. In a 'given in' swap, 'tokenIn' must equal
         * the previous swap's `tokenOut`. For a 'given out' swap, `tokenOut` must equal the previous swap's `tokenIn`.
         *
         * The `assets` array contains the addresses of all assets involved in the swaps. These are either token addresses,
         * or the IAsset sentinel value for ETH (the zero address). Each entry in the `swaps` array specifies tokens in and
         * out by referencing an index in `assets`. Note that Pools never interact with ETH directly: it will be wrapped to
         * or unwrapped from WETH by the Vault.
         *
         * Internal Balance usage, sender, and recipient are determined by the `funds` struct. The `limits` array specifies
         * the minimum or maximum amount of each token the vault is allowed to transfer.
         *
         * `batchSwap` can be used to make a single swap, like `swap` does, but doing so requires more gas than the
         * equivalent `swap` call.
         *
         * Emits `Swap` events.
         */
        function batchSwap(
            SwapKind kind,
            BatchSwapStep[] memory swaps,
            IAsset[] memory assets,
            FundManagement memory funds,
            int256[] memory limits,
            uint256 deadline
        ) external payable returns (int256[] memory);
        /**
         * @dev Data for each individual swap executed by `batchSwap`. The asset in and out fields are indexes into the
         * `assets` array passed to that function, and ETH assets are converted to WETH.
         *
         * If `amount` is zero, the multihop mechanism is used to determine the actual amount based on the amount in/out
         * from the previous swap, depending on the swap kind.
         *
         * The `userData` field is ignored by the Vault, but forwarded to the Pool in the `onSwap` hook, and may be
         * used to extend swap behavior.
         */
        struct BatchSwapStep {
            bytes32 poolId;
            uint256 assetInIndex;
            uint256 assetOutIndex;
            uint256 amount;
            bytes userData;
        }
        /**
         * @dev Emitted for each individual swap performed by `swap` or `batchSwap`.
         */
        event Swap(
            bytes32 indexed poolId,
            IERC20 indexed tokenIn,
            IERC20 indexed tokenOut,
            uint256 amountIn,
            uint256 amountOut
        );
        /**
         * @dev All tokens in a swap are either sent from the `sender` account to the Vault, or from the Vault to the
         * `recipient` account.
         *
         * If the caller is not `sender`, it must be an authorized relayer for them.
         *
         * If `fromInternalBalance` is true, the `sender`'s Internal Balance will be preferred, performing an ERC20
         * transfer for the difference between the requested amount and the User's Internal Balance (if any). The `sender`
         * must have allowed the Vault to use their tokens via `IERC20.approve()`. This matches the behavior of
         * `joinPool`.
         *
         * If `toInternalBalance` is true, tokens will be deposited to `recipient`'s internal balance instead of
         * transferred. This matches the behavior of `exitPool`.
         *
         * Note that ETH cannot be deposited to or withdrawn from Internal Balance: attempting to do so will trigger a
         * revert.
         */
        struct FundManagement {
            address sender;
            bool fromInternalBalance;
            address payable recipient;
            bool toInternalBalance;
        }
        /**
         * @dev Simulates a call to `batchSwap`, returning an array of Vault asset deltas. Calls to `swap` cannot be
         * simulated directly, but an equivalent `batchSwap` call can and will yield the exact same result.
         *
         * Each element in the array corresponds to the asset at the same index, and indicates the number of tokens (or ETH)
         * the Vault would take from the sender (if positive) or send to the recipient (if negative). The arguments it
         * receives are the same that an equivalent `batchSwap` call would receive.
         *
         * Unlike `batchSwap`, this function performs no checks on the sender or recipient field in the `funds` struct.
         * This makes it suitable to be called by off-chain applications via eth_call without needing to hold tokens,
         * approve them for the Vault, or even know a user's address.
         *
         * Note that this function is not 'view' (due to implementation details): the client code must explicitly execute
         * eth_call instead of eth_sendTransaction.
         */
        function queryBatchSwap(
            SwapKind kind,
            BatchSwapStep[] memory swaps,
            IAsset[] memory assets,
            FundManagement memory funds
        ) external returns (int256[] memory assetDeltas);
        // Flash Loans
        /**
         * @dev Performs a 'flash loan', sending tokens to `recipient`, executing the `receiveFlashLoan` hook on it,
         * and then reverting unless the tokens plus a proportional protocol fee have been returned.
         *
         * The `tokens` and `amounts` arrays must have the same length, and each entry in these indicates the loan amount
         * for each token contract. `tokens` must be sorted in ascending order.
         *
         * The 'userData' field is ignored by the Vault, and forwarded as-is to `recipient` as part of the
         * `receiveFlashLoan` call.
         *
         * Emits `FlashLoan` events.
         */
        function flashLoan(
            IFlashLoanRecipient recipient,
            IERC20[] memory tokens,
            uint256[] memory amounts,
            bytes memory userData
        ) external;
        /**
         * @dev Emitted for each individual flash loan performed by `flashLoan`.
         */
        event FlashLoan(IFlashLoanRecipient indexed recipient, IERC20 indexed token, uint256 amount, uint256 feeAmount);
        // Asset Management
        //
        // Each token registered for a Pool can be assigned an Asset Manager, which is able to freely withdraw the Pool's
        // tokens from the Vault, deposit them, or assign arbitrary values to its `managed` balance (see
        // `getPoolTokenInfo`). This makes them extremely powerful and dangerous. Even if an Asset Manager only directly
        // controls one of the tokens in a Pool, a malicious manager could set that token's balance to manipulate the
        // prices of the other tokens, and then drain the Pool with swaps. The risk of using Asset Managers is therefore
        // not constrained to the tokens they are managing, but extends to the entire Pool's holdings.
        //
        // However, a properly designed Asset Manager smart contract can be safely used for the Pool's benefit,
        // for example by lending unused tokens out for interest, or using them to participate in voting protocols.
        //
        // This concept is unrelated to the IAsset interface.
        /**
         * @dev Performs a set of Pool balance operations, which may be either withdrawals, deposits or updates.
         *
         * Pool Balance management features batching, which means a single contract call can be used to perform multiple
         * operations of different kinds, with different Pools and tokens, at once.
         *
         * For each operation, the caller must be registered as the Asset Manager for `token` in `poolId`.
         */
        function managePoolBalance(PoolBalanceOp[] memory ops) external;
        struct PoolBalanceOp {
            PoolBalanceOpKind kind;
            bytes32 poolId;
            IERC20 token;
            uint256 amount;
        }
        /**
         * Withdrawals decrease the Pool's cash, but increase its managed balance, leaving the total balance unchanged.
         *
         * Deposits increase the Pool's cash, but decrease its managed balance, leaving the total balance unchanged.
         *
         * Updates don't affect the Pool's cash balance, but because the managed balance changes, it does alter the total.
         * The external amount can be either increased or decreased by this call (i.e., reporting a gain or a loss).
         */
        enum PoolBalanceOpKind { WITHDRAW, DEPOSIT, UPDATE }
        /**
         * @dev Emitted when a Pool's token Asset Manager alters its balance via `managePoolBalance`.
         */
        event PoolBalanceManaged(
            bytes32 indexed poolId,
            address indexed assetManager,
            IERC20 indexed token,
            int256 cashDelta,
            int256 managedDelta
        );
        // Protocol Fees
        //
        // Some operations cause the Vault to collect tokens in the form of protocol fees, which can then be withdrawn by
        // permissioned accounts.
        //
        // There are two kinds of protocol fees:
        //
        //  - flash loan fees: charged on all flash loans, as a percentage of the amounts lent.
        //
        //  - swap fees: a percentage of the fees charged by Pools when performing swaps. For a number of reasons, including
        // swap gas costs and interface simplicity, protocol swap fees are not charged on each individual swap. Rather,
        // Pools are expected to keep track of how much they have charged in swap fees, and pay any outstanding debts to the
        // Vault when they are joined or exited. This prevents users from joining a Pool with unpaid debt, as well as
        // exiting a Pool in debt without first paying their share.
        /**
         * @dev Returns the current protocol fee module.
         */
        function getProtocolFeesCollector() external view returns (IProtocolFeesCollector);
        /**
         * @dev Safety mechanism to pause most Vault operations in the event of an emergency - typically detection of an
         * error in some part of the system.
         *
         * The Vault can only be paused during an initial time period, after which pausing is forever disabled.
         *
         * While the contract is paused, the following features are disabled:
         * - depositing and transferring internal balance
         * - transferring external balance (using the Vault's allowance)
         * - swaps
         * - joining Pools
         * - Asset Manager interactions
         *
         * Internal Balance can still be withdrawn, and Pools exited.
         */
        function setPaused(bool paused) external;
        /**
         * @dev Returns the Vault's WETH instance.
         */
        function WETH() external view returns (IWETH);
        // solhint-disable-previous-line func-name-mixedcase
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "../solidity-utils/openzeppelin/IERC20.sol";
    import "./IVault.sol";
    interface IPoolSwapStructs {
        // This is not really an interface - it just defines common structs used by other interfaces: IGeneralPool and
        // IMinimalSwapInfoPool.
        //
        // This data structure represents a request for a token swap, where `kind` indicates the swap type ('given in' or
        // 'given out') which indicates whether or not the amount sent by the pool is known.
        //
        // The pool receives `tokenIn` and sends `tokenOut`. `amount` is the number of `tokenIn` tokens the pool will take
        // in, or the number of `tokenOut` tokens the Pool will send out, depending on the given swap `kind`.
        //
        // All other fields are not strictly necessary for most swaps, but are provided to support advanced scenarios in
        // some Pools.
        //
        // `poolId` is the ID of the Pool involved in the swap - this is useful for Pool contracts that implement more than
        // one Pool.
        //
        // The meaning of `lastChangeBlock` depends on the Pool specialization:
        //  - Two Token or Minimal Swap Info: the last block in which either `tokenIn` or `tokenOut` changed its total
        //    balance.
        //  - General: the last block in which *any* of the Pool's registered tokens changed its total balance.
        //
        // `from` is the origin address for the funds the Pool receives, and `to` is the destination address
        // where the Pool sends the outgoing tokens.
        //
        // `userData` is extra data provided by the caller - typically a signature from a trusted party.
        struct SwapRequest {
            IVault.SwapKind kind;
            IERC20 tokenIn;
            IERC20 tokenOut;
            uint256 amount;
            // Misc data
            bytes32 poolId;
            uint256 lastChangeBlock;
            address from;
            address to;
            bytes userData;
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    interface IAuthentication {
        /**
         * @dev Returns the action identifier associated with the external function described by `selector`.
         */
        function getActionId(bytes4 selector) external view returns (bytes32);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    /**
     * @dev Interface for the SignatureValidator helper, used to support meta-transactions.
     */
    interface ISignaturesValidator {
        /**
         * @dev Returns the EIP712 domain separator.
         */
        function getDomainSeparator() external view returns (bytes32);
        /**
         * @dev Returns the next nonce used by an address to sign messages.
         */
        function getNextNonce(address user) external view returns (uint256);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    /**
     * @dev Interface for the TemporarilyPausable helper.
     */
    interface ITemporarilyPausable {
        /**
         * @dev Emitted every time the pause state changes by `_setPaused`.
         */
        event PausedStateChanged(bool paused);
        /**
         * @dev Returns the current paused state.
         */
        function getPausedState()
            external
            view
            returns (
                bool paused,
                uint256 pauseWindowEndTime,
                uint256 bufferPeriodEndTime
            );
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "../openzeppelin/IERC20.sol";
    /**
     * @dev Interface for WETH9.
     * See https://github.com/gnosis/canonical-weth/blob/0dd1ea3e295eef916d0c6223ec63141137d22d67/contracts/WETH9.sol
     */
    interface IWETH is IERC20 {
        function deposit() external payable;
        function withdraw(uint256 amount) external;
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    /**
     * @dev This is an empty interface used to represent either ERC20-conforming token contracts or ETH (using the zero
     * address sentinel value). We're just relying on the fact that `interface` can be used to declare new address-like
     * types.
     *
     * This concept is unrelated to a Pool's Asset Managers.
     */
    interface IAsset {
        // solhint-disable-previous-line no-empty-blocks
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    interface IAuthorizer {
        /**
         * @dev Returns true if `account` can perform the action described by `actionId` in the contract `where`.
         */
        function canPerform(
            bytes32 actionId,
            address account,
            address where
        ) external view returns (bool);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    // Inspired by Aave Protocol's IFlashLoanReceiver.
    import "../solidity-utils/openzeppelin/IERC20.sol";
    interface IFlashLoanRecipient {
        /**
         * @dev When `flashLoan` is called on the Vault, it invokes the `receiveFlashLoan` hook on the recipient.
         *
         * At the time of the call, the Vault will have transferred `amounts` for `tokens` to the recipient. Before this
         * call returns, the recipient must have transferred `amounts` plus `feeAmounts` for each token back to the
         * Vault, or else the entire flash loan will revert.
         *
         * `userData` is the same value passed in the `IVault.flashLoan` call.
         */
        function receiveFlashLoan(
            IERC20[] memory tokens,
            uint256[] memory amounts,
            uint256[] memory feeAmounts,
            bytes memory userData
        ) external;
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "../solidity-utils/openzeppelin/IERC20.sol";
    import "./IVault.sol";
    import "./IAuthorizer.sol";
    interface IProtocolFeesCollector {
        event SwapFeePercentageChanged(uint256 newSwapFeePercentage);
        event FlashLoanFeePercentageChanged(uint256 newFlashLoanFeePercentage);
        function withdrawCollectedFees(
            IERC20[] calldata tokens,
            uint256[] calldata amounts,
            address recipient
        ) external;
        function setSwapFeePercentage(uint256 newSwapFeePercentage) external;
        function setFlashLoanFeePercentage(uint256 newFlashLoanFeePercentage) external;
        function getSwapFeePercentage() external view returns (uint256);
        function getFlashLoanFeePercentage() external view returns (uint256);
        function getCollectedFeeAmounts(IERC20[] memory tokens) external view returns (uint256[] memory feeAmounts);
        function getAuthorizer() external view returns (IAuthorizer);
        function vault() external view returns (IVault);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "../solidity-utils/openzeppelin/IERC20.sol";
    interface IAssetManager {
        /**
         * @notice Emitted when asset manager is rebalanced
         */
        event Rebalance(bytes32 poolId);
        /**
         * @notice Sets the config
         */
        function setConfig(bytes32 poolId, bytes calldata config) external;
        /**
         * Note: No function to read the asset manager config is included in IAssetManager
         * as the signature is expected to vary between asset manager implementations
         */
        /**
         * @notice Returns the asset manager's token
         */
        function getToken() external view returns (IERC20);
        /**
         * @return the current assets under management of this asset manager
         */
        function getAUM(bytes32 poolId) external view returns (uint256);
        /**
         * @return poolCash - The up-to-date cash balance of the pool
         * @return poolManaged - The up-to-date managed balance of the pool
         */
        function getPoolBalances(bytes32 poolId) external view returns (uint256 poolCash, uint256 poolManaged);
        /**
         * @return The difference in tokens between the target investment
         * and the currently invested amount (i.e. the amount that can be invested)
         */
        function maxInvestableBalance(bytes32 poolId) external view returns (int256);
        /**
         * @notice Updates the Vault on the value of the pool's investment returns
         */
        function updateBalanceOfPool(bytes32 poolId) external;
        /**
         * @notice Determines whether the pool should rebalance given the provided balances
         */
        function shouldRebalance(uint256 cash, uint256 managed) external view returns (bool);
        /**
         * @notice Rebalances funds between the pool and the asset manager to maintain target investment percentage.
         * @param poolId - the poolId of the pool to be rebalanced
         * @param force - a boolean representing whether a rebalance should be forced even when the pool is near balance
         */
        function rebalance(bytes32 poolId, bool force) external;
        /**
         * @notice allows an authorized rebalancer to remove capital to facilitate large withdrawals
         * @param poolId - the poolId of the pool to withdraw funds back to
         * @param amount - the amount of tokens to withdraw back to the pool
         */
        function capitalOut(bytes32 poolId, uint256 amount) external;
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "../solidity-utils/openzeppelin/IERC20.sol";
    interface IControlledPool {
        function setSwapFeePercentage(uint256 swapFeePercentage) external;
        function setAssetManagerPoolConfig(IERC20 token, bytes memory poolConfig) external;
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    import "../math/Math.sol";
    /**
     * @dev Library for encoding and decoding values stored inside a 256 bit word. Typically used to pack multiple values in
     * a single storage slot, saving gas by performing less storage accesses.
     *
     * Each value is defined by its size and the least significant bit in the word, also known as offset. For example, two
     * 128 bit values may be encoded in a word by assigning one an offset of 0, and the other an offset of 128.
     *
     * We could use Solidity structs to pack values together in a single storage slot instead of relying on a custom and
     * error-prone library, but unfortunately Solidity only allows for structs to live in either storage, calldata or
     * memory. Because a memory struct uses not just memory but also a slot in the stack (to store its memory location),
     * using memory for word-sized values (i.e. of 256 bits or less) is strictly less gas performant, and doesn't even
     * prevent stack-too-deep issues. This is compounded by the fact that Balancer contracts typically are memory-intensive,
     * and the cost of accesing memory increases quadratically with the number of allocated words. Manual packing and
     * unpacking is therefore the preferred approach.
     */
    library WordCodec {
        // Masks are values with the least significant N bits set. They can be used to extract an encoded value from a word,
        // or to insert a new one replacing the old.
        uint256 private constant _MASK_1 = 2**(1) - 1;
        uint256 private constant _MASK_192 = 2**(192) - 1;
        // In-place insertion
        /**
         * @dev Inserts an unsigned integer of bitLength, shifted by an offset, into a 256 bit word,
         * replacing the old value. Returns the new word.
         */
        function insertUint(
            bytes32 word,
            uint256 value,
            uint256 offset,
            uint256 bitLength
        ) internal pure returns (bytes32) {
            _validateEncodingParams(value, offset, bitLength);
            uint256 mask = (1 << bitLength) - 1;
            bytes32 clearedWord = bytes32(uint256(word) & ~(mask << offset));
            return clearedWord | bytes32(value << offset);
        }
        /**
         * @dev Inserts a signed integer shifted by an offset into a 256 bit word, replacing the old value. Returns
         * the new word.
         *
         * Assumes `value` can be represented using `bitLength` bits.
         */
        function insertInt(
            bytes32 word,
            int256 value,
            uint256 offset,
            uint256 bitLength
        ) internal pure returns (bytes32) {
            _validateEncodingParams(value, offset, bitLength);
            uint256 mask = (1 << bitLength) - 1;
            bytes32 clearedWord = bytes32(uint256(word) & ~(mask << offset));
            // Integer values need masking to remove the upper bits of negative values.
            return clearedWord | bytes32((uint256(value) & mask) << offset);
        }
        // Encoding
        /**
         * @dev Encodes an unsigned integer shifted by an offset. Ensures value fits within
         * `bitLength` bits.
         *
         * The return value can be ORed bitwise with other encoded values to form a 256 bit word.
         */
        function encodeUint(
            uint256 value,
            uint256 offset,
            uint256 bitLength
        ) internal pure returns (bytes32) {
            _validateEncodingParams(value, offset, bitLength);
            return bytes32(value << offset);
        }
        /**
         * @dev Encodes a signed integer shifted by an offset.
         *
         * The return value can be ORed bitwise with other encoded values to form a 256 bit word.
         */
        function encodeInt(
            int256 value,
            uint256 offset,
            uint256 bitLength
        ) internal pure returns (bytes32) {
            _validateEncodingParams(value, offset, bitLength);
            uint256 mask = (1 << bitLength) - 1;
            // Integer values need masking to remove the upper bits of negative values.
            return bytes32((uint256(value) & mask) << offset);
        }
        // Decoding
        /**
         * @dev Decodes and returns an unsigned integer with `bitLength` bits, shifted by an offset, from a 256 bit word.
         */
        function decodeUint(
            bytes32 word,
            uint256 offset,
            uint256 bitLength
        ) internal pure returns (uint256) {
            return uint256(word >> offset) & ((1 << bitLength) - 1);
        }
        /**
         * @dev Decodes and returns a signed integer with `bitLength` bits, shifted by an offset, from a 256 bit word.
         */
        function decodeInt(
            bytes32 word,
            uint256 offset,
            uint256 bitLength
        ) internal pure returns (int256) {
            int256 maxInt = int256((1 << (bitLength - 1)) - 1);
            uint256 mask = (1 << bitLength) - 1;
            int256 value = int256(uint256(word >> offset) & mask);
            // In case the decoded value is greater than the max positive integer that can be represented with bitLength
            // bits, we know it was originally a negative integer. Therefore, we mask it to restore the sign in the 256 bit
            // representation.
            return value > maxInt ? (value | int256(~mask)) : value;
        }
        // Special cases
        /**
         * @dev Decodes and returns a boolean shifted by an offset from a 256 bit word.
         */
        function decodeBool(bytes32 word, uint256 offset) internal pure returns (bool) {
            return (uint256(word >> offset) & _MASK_1) == 1;
        }
        /**
         * @dev Inserts a 192 bit value shifted by an offset into a 256 bit word, replacing the old value.
         * Returns the new word.
         *
         * Assumes `value` can be represented using 192 bits.
         */
        function insertBits192(
            bytes32 word,
            bytes32 value,
            uint256 offset
        ) internal pure returns (bytes32) {
            bytes32 clearedWord = bytes32(uint256(word) & ~(_MASK_192 << offset));
            return clearedWord | bytes32((uint256(value) & _MASK_192) << offset);
        }
        /**
         * @dev Inserts a boolean value shifted by an offset into a 256 bit word, replacing the old value. Returns the new
         * word.
         */
        function insertBool(
            bytes32 word,
            bool value,
            uint256 offset
        ) internal pure returns (bytes32) {
            bytes32 clearedWord = bytes32(uint256(word) & ~(_MASK_1 << offset));
            return clearedWord | bytes32(uint256(value ? 1 : 0) << offset);
        }
        // Helpers
        function _validateEncodingParams(
            uint256 value,
            uint256 offset,
            uint256 bitLength
        ) private pure {
            _require(offset < 256, Errors.OUT_OF_BOUNDS);
            // We never accept 256 bit values (which would make the codec pointless), and the larger the offset the smaller
            // the maximum bit length.
            _require(bitLength >= 1 && bitLength <= Math.min(255, 256 - offset), Errors.OUT_OF_BOUNDS);
            // Testing unsigned values for size is straightforward: their upper bits must be cleared.
            _require(value >> bitLength == 0, Errors.CODEC_OVERFLOW);
        }
        function _validateEncodingParams(
            int256 value,
            uint256 offset,
            uint256 bitLength
        ) private pure {
            _require(offset < 256, Errors.OUT_OF_BOUNDS);
            // We never accept 256 bit values (which would make the codec pointless), and the larger the offset the smaller
            // the maximum bit length.
            _require(bitLength >= 1 && bitLength <= Math.min(255, 256 - offset), Errors.OUT_OF_BOUNDS);
            // Testing signed values for size is a bit more involved.
            if (value >= 0) {
                // For positive values, we can simply check that the upper bits are clear. Notice we remove one bit from the
                // length for the sign bit.
                _require(value >> (bitLength - 1) == 0, Errors.CODEC_OVERFLOW);
            } else {
                // Negative values can receive the same treatment by making them positive, with the caveat that the range
                // for negative values in two's complement supports one more value than for the positive case.
                _require(Math.abs(value + 1) >> (bitLength - 1) == 0, Errors.CODEC_OVERFLOW);
            }
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/ITemporarilyPausable.sol";
    /**
     * @dev Allows for a contract to be paused during an initial period after deployment, disabling functionality. Can be
     * used as an emergency switch in case a security vulnerability or threat is identified.
     *
     * The contract can only be paused during the Pause Window, a period that starts at deployment. It can also be
     * unpaused and repaused any number of times during this period. This is intended to serve as a safety measure: it lets
     * system managers react quickly to potentially dangerous situations, knowing that this action is reversible if careful
     * analysis later determines there was a false alarm.
     *
     * If the contract is paused when the Pause Window finishes, it will remain in the paused state through an additional
     * Buffer Period, after which it will be automatically unpaused forever. This is to ensure there is always enough time
     * to react to an emergency, even if the threat is discovered shortly before the Pause Window expires.
     *
     * Note that since the contract can only be paused within the Pause Window, unpausing during the Buffer Period is
     * irreversible.
     */
    abstract contract TemporarilyPausable is ITemporarilyPausable {
        // The Pause Window and Buffer Period are timestamp-based: they should not be relied upon for sub-minute accuracy.
        // solhint-disable not-rely-on-time
        uint256 private constant _MAX_PAUSE_WINDOW_DURATION = 90 days;
        uint256 private constant _MAX_BUFFER_PERIOD_DURATION = 30 days;
        uint256 private immutable _pauseWindowEndTime;
        uint256 private immutable _bufferPeriodEndTime;
        bool private _paused;
        constructor(uint256 pauseWindowDuration, uint256 bufferPeriodDuration) {
            _require(pauseWindowDuration <= _MAX_PAUSE_WINDOW_DURATION, Errors.MAX_PAUSE_WINDOW_DURATION);
            _require(bufferPeriodDuration <= _MAX_BUFFER_PERIOD_DURATION, Errors.MAX_BUFFER_PERIOD_DURATION);
            uint256 pauseWindowEndTime = block.timestamp + pauseWindowDuration;
            _pauseWindowEndTime = pauseWindowEndTime;
            _bufferPeriodEndTime = pauseWindowEndTime + bufferPeriodDuration;
        }
        /**
         * @dev Reverts if the contract is paused.
         */
        modifier whenNotPaused() {
            _ensureNotPaused();
            _;
        }
        /**
         * @dev Returns the current contract pause status, as well as the end times of the Pause Window and Buffer
         * Period.
         */
        function getPausedState()
            external
            view
            override
            returns (
                bool paused,
                uint256 pauseWindowEndTime,
                uint256 bufferPeriodEndTime
            )
        {
            paused = !_isNotPaused();
            pauseWindowEndTime = _getPauseWindowEndTime();
            bufferPeriodEndTime = _getBufferPeriodEndTime();
        }
        /**
         * @dev Sets the pause state to `paused`. The contract can only be paused until the end of the Pause Window, and
         * unpaused until the end of the Buffer Period.
         *
         * Once the Buffer Period expires, this function reverts unconditionally.
         */
        function _setPaused(bool paused) internal {
            if (paused) {
                _require(block.timestamp < _getPauseWindowEndTime(), Errors.PAUSE_WINDOW_EXPIRED);
            } else {
                _require(block.timestamp < _getBufferPeriodEndTime(), Errors.BUFFER_PERIOD_EXPIRED);
            }
            _paused = paused;
            emit PausedStateChanged(paused);
        }
        /**
         * @dev Reverts if the contract is paused.
         */
        function _ensureNotPaused() internal view {
            _require(_isNotPaused(), Errors.PAUSED);
        }
        /**
         * @dev Reverts if the contract is not paused.
         */
        function _ensurePaused() internal view {
            _require(!_isNotPaused(), Errors.NOT_PAUSED);
        }
        /**
         * @dev Returns true if the contract is unpaused.
         *
         * Once the Buffer Period expires, the gas cost of calling this function is reduced dramatically, as storage is no
         * longer accessed.
         */
        function _isNotPaused() internal view returns (bool) {
            // After the Buffer Period, the (inexpensive) timestamp check short-circuits the storage access.
            return block.timestamp > _getBufferPeriodEndTime() || !_paused;
        }
        // These getters lead to reduced bytecode size by inlining the immutable variables in a single place.
        function _getPauseWindowEndTime() private view returns (uint256) {
            return _pauseWindowEndTime;
        }
        function _getBufferPeriodEndTime() private view returns (uint256) {
            return _bufferPeriodEndTime;
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/openzeppelin/IERC20.sol";
    import "./SafeMath.sol";
    /**
     * @dev Implementation of the {IERC20} interface.
     *
     * This implementation is agnostic to the way tokens are created. This means
     * that a supply mechanism has to be added in a derived contract using {_mint}.
     * For a generic mechanism see {ERC20PresetMinterPauser}.
     *
     * TIP: For a detailed writeup see our guide
     * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
     * to implement supply mechanisms].
     *
     * We have followed general OpenZeppelin guidelines: functions revert instead
     * of returning `false` on failure. This behavior is nonetheless conventional
     * and does not conflict with the expectations of ERC20 applications.
     *
     * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
     * This allows applications to reconstruct the allowance for all accounts just
     * by listening to said events. Other implementations of the EIP may not emit
     * these events, as it isn't required by the specification.
     *
     * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
     * functions have been added to mitigate the well-known issues around setting
     * allowances. See {IERC20-approve}.
     */
    contract ERC20 is IERC20 {
        using SafeMath for uint256;
        mapping(address => uint256) private _balances;
        mapping(address => mapping(address => uint256)) private _allowances;
        uint256 private _totalSupply;
        string private _name;
        string private _symbol;
        uint8 private _decimals;
        /**
         * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
         * a default value of 18.
         *
         * To select a different value for {decimals}, use {_setupDecimals}.
         *
         * All three of these values are immutable: they can only be set once during
         * construction.
         */
        constructor(string memory name_, string memory symbol_) {
            _name = name_;
            _symbol = symbol_;
            _decimals = 18;
        }
        /**
         * @dev Returns the name of the token.
         */
        function name() public view returns (string memory) {
            return _name;
        }
        /**
         * @dev Returns the symbol of the token, usually a shorter version of the
         * name.
         */
        function symbol() public view returns (string memory) {
            return _symbol;
        }
        /**
         * @dev Returns the number of decimals used to get its user representation.
         * For example, if `decimals` equals `2`, a balance of `505` tokens should
         * be displayed to a user as `5,05` (`505 / 10 ** 2`).
         *
         * Tokens usually opt for a value of 18, imitating the relationship between
         * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
         * called.
         *
         * NOTE: This information is only used for _display_ purposes: it in
         * no way affects any of the arithmetic of the contract, including
         * {IERC20-balanceOf} and {IERC20-transfer}.
         */
        function decimals() public view returns (uint8) {
            return _decimals;
        }
        /**
         * @dev See {IERC20-totalSupply}. The total supply should only be read using this function
         *
         * Can be overridden by derived contracts to store the total supply in a different way (e.g. packed with other
         * storage values).
         */
        function totalSupply() public view virtual override returns (uint256) {
            return _totalSupply;
        }
        /**
         * @dev Sets a new value for the total supply. It should only be set using this function.
         *
         * * Can be overridden by derived contracts to store the total supply in a different way (e.g. packed with other
         * storage values).
         */
        function _setTotalSupply(uint256 value) internal virtual {
            _totalSupply = value;
        }
        /**
         * @dev See {IERC20-balanceOf}.
         */
        function balanceOf(address account) public view override returns (uint256) {
            return _balances[account];
        }
        /**
         * @dev See {IERC20-transfer}.
         *
         * Requirements:
         *
         * - `recipient` cannot be the zero address.
         * - the caller must have a balance of at least `amount`.
         */
        function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
            _transfer(msg.sender, recipient, amount);
            return true;
        }
        /**
         * @dev See {IERC20-allowance}.
         */
        function allowance(address owner, address spender) public view virtual override returns (uint256) {
            return _allowances[owner][spender];
        }
        /**
         * @dev See {IERC20-approve}.
         *
         * Requirements:
         *
         * - `spender` cannot be the zero address.
         */
        function approve(address spender, uint256 amount) public virtual override returns (bool) {
            _approve(msg.sender, spender, amount);
            return true;
        }
        /**
         * @dev See {IERC20-transferFrom}.
         *
         * Emits an {Approval} event indicating the updated allowance. This is not
         * required by the EIP. See the note at the beginning of {ERC20}.
         *
         * Requirements:
         *
         * - `sender` and `recipient` cannot be the zero address.
         * - `sender` must have a balance of at least `amount`.
         * - the caller must have allowance for ``sender``'s tokens of at least
         * `amount`.
         */
        function transferFrom(
            address sender,
            address recipient,
            uint256 amount
        ) public virtual override returns (bool) {
            _transfer(sender, recipient, amount);
            _approve(
                sender,
                msg.sender,
                _allowances[sender][msg.sender].sub(amount, Errors.ERC20_TRANSFER_EXCEEDS_ALLOWANCE)
            );
            return true;
        }
        /**
         * @dev Atomically increases the allowance granted to `spender` by the caller.
         *
         * This is an alternative to {approve} that can be used as a mitigation for
         * problems described in {IERC20-approve}.
         *
         * Emits an {Approval} event indicating the updated allowance.
         *
         * Requirements:
         *
         * - `spender` cannot be the zero address.
         */
        function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
            _approve(msg.sender, spender, _allowances[msg.sender][spender].add(addedValue));
            return true;
        }
        /**
         * @dev Atomically decreases the allowance granted to `spender` by the caller.
         *
         * This is an alternative to {approve} that can be used as a mitigation for
         * problems described in {IERC20-approve}.
         *
         * Emits an {Approval} event indicating the updated allowance.
         *
         * Requirements:
         *
         * - `spender` cannot be the zero address.
         * - `spender` must have allowance for the caller of at least
         * `subtractedValue`.
         */
        function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
            _approve(
                msg.sender,
                spender,
                _allowances[msg.sender][spender].sub(subtractedValue, Errors.ERC20_DECREASED_ALLOWANCE_BELOW_ZERO)
            );
            return true;
        }
        /**
         * @dev Moves tokens `amount` from `sender` to `recipient`.
         *
         * This is internal function is equivalent to {transfer}, and can be used to
         * e.g. implement automatic token fees, slashing mechanisms, etc.
         *
         * Emits a {Transfer} event.
         *
         * Requirements:
         *
         * - `sender` cannot be the zero address.
         * - `recipient` cannot be the zero address.
         * - `sender` must have a balance of at least `amount`.
         */
        function _transfer(
            address sender,
            address recipient,
            uint256 amount
        ) internal virtual {
            _require(sender != address(0), Errors.ERC20_TRANSFER_FROM_ZERO_ADDRESS);
            _require(recipient != address(0), Errors.ERC20_TRANSFER_TO_ZERO_ADDRESS);
            _beforeTokenTransfer(sender, recipient, amount);
            _balances[sender] = _balances[sender].sub(amount, Errors.ERC20_TRANSFER_EXCEEDS_BALANCE);
            _balances[recipient] = _balances[recipient].add(amount);
            emit Transfer(sender, recipient, amount);
        }
        /** @dev Creates `amount` tokens and assigns them to `account`, increasing
         * the total supply.
         *
         * Emits a {Transfer} event with `from` set to the zero address.
         *
         * Requirements:
         *
         * - `to` cannot be the zero address.
         */
        function _mint(address account, uint256 amount) internal virtual {
            _beforeTokenTransfer(address(0), account, amount);
            _setTotalSupply(totalSupply().add(amount));
            _balances[account] = _balances[account].add(amount);
            emit Transfer(address(0), account, amount);
        }
        /**
         * @dev Destroys `amount` tokens from `account`, reducing the
         * total supply.
         *
         * Emits a {Transfer} event with `to` set to the zero address.
         *
         * Requirements:
         *
         * - `account` cannot be the zero address.
         * - `account` must have at least `amount` tokens.
         */
        function _burn(address account, uint256 amount) internal virtual {
            _require(account != address(0), Errors.ERC20_BURN_FROM_ZERO_ADDRESS);
            _beforeTokenTransfer(account, address(0), amount);
            _balances[account] = _balances[account].sub(amount, Errors.ERC20_BURN_EXCEEDS_BALANCE);
            _setTotalSupply(totalSupply().sub(amount));
            emit Transfer(account, address(0), amount);
        }
        /**
         * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
         *
         * This internal function is equivalent to `approve`, and can be used to
         * e.g. set automatic allowances for certain subsystems, etc.
         *
         * Emits an {Approval} event.
         *
         * Requirements:
         *
         * - `owner` cannot be the zero address.
         * - `spender` cannot be the zero address.
         */
        function _approve(
            address owner,
            address spender,
            uint256 amount
        ) internal virtual {
            _allowances[owner][spender] = amount;
            emit Approval(owner, spender, amount);
        }
        /**
         * @dev Sets {decimals} to a value other than the default one of 18.
         *
         * WARNING: This function should only be called from the constructor. Most
         * applications that interact with token contracts will not expect
         * {decimals} to ever change, and may work incorrectly if it does.
         */
        function _setupDecimals(uint8 decimals_) internal {
            _decimals = decimals_;
        }
        /**
         * @dev Hook that is called before any transfer of tokens. This includes
         * minting and burning.
         *
         * Calling conditions:
         *
         * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
         * will be to transferred to `to`.
         * - when `from` is zero, `amount` tokens will be minted for `to`.
         * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
         * - `from` and `to` are never both zero.
         *
         * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
         */
        function _beforeTokenTransfer(
            address from,
            address to,
            uint256 amount
        ) internal virtual {
            // solhint-disable-previous-line no-empty-blocks
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    /**
     * @dev Wrappers over Solidity's arithmetic operations with added overflow checks.
     * Adapted from OpenZeppelin's SafeMath library.
     */
    library Math {
        /**
         * @dev Returns the absolute value of a signed integer.
         */
        function abs(int256 a) internal pure returns (uint256) {
            return a > 0 ? uint256(a) : uint256(-a);
        }
        /**
         * @dev Returns the addition of two unsigned integers of 256 bits, reverting on overflow.
         */
        function add(uint256 a, uint256 b) internal pure returns (uint256) {
            uint256 c = a + b;
            _require(c >= a, Errors.ADD_OVERFLOW);
            return c;
        }
        /**
         * @dev Returns the addition of two signed integers, reverting on overflow.
         */
        function add(int256 a, int256 b) internal pure returns (int256) {
            int256 c = a + b;
            _require((b >= 0 && c >= a) || (b < 0 && c < a), Errors.ADD_OVERFLOW);
            return c;
        }
        /**
         * @dev Returns the subtraction of two unsigned integers of 256 bits, reverting on overflow.
         */
        function sub(uint256 a, uint256 b) internal pure returns (uint256) {
            _require(b <= a, Errors.SUB_OVERFLOW);
            uint256 c = a - b;
            return c;
        }
        /**
         * @dev Returns the subtraction of two signed integers, reverting on overflow.
         */
        function sub(int256 a, int256 b) internal pure returns (int256) {
            int256 c = a - b;
            _require((b >= 0 && c <= a) || (b < 0 && c > a), Errors.SUB_OVERFLOW);
            return c;
        }
        /**
         * @dev Returns the largest of two numbers of 256 bits.
         */
        function max(uint256 a, uint256 b) internal pure returns (uint256) {
            return a >= b ? a : b;
        }
        /**
         * @dev Returns the smallest of two numbers of 256 bits.
         */
        function min(uint256 a, uint256 b) internal pure returns (uint256) {
            return a < b ? a : b;
        }
        function mul(uint256 a, uint256 b) internal pure returns (uint256) {
            uint256 c = a * b;
            _require(a == 0 || c / a == b, Errors.MUL_OVERFLOW);
            return c;
        }
        function div(
            uint256 a,
            uint256 b,
            bool roundUp
        ) internal pure returns (uint256) {
            return roundUp ? divUp(a, b) : divDown(a, b);
        }
        function divDown(uint256 a, uint256 b) internal pure returns (uint256) {
            _require(b != 0, Errors.ZERO_DIVISION);
            return a / b;
        }
        function divUp(uint256 a, uint256 b) internal pure returns (uint256) {
            _require(b != 0, Errors.ZERO_DIVISION);
            if (a == 0) {
                return 0;
            } else {
                return 1 + (a - 1) / b;
            }
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-interfaces/contracts/vault/IVault.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/ERC20Permit.sol";
    /**
     * @title Highly opinionated token implementation
     * @author Balancer Labs
     * @dev
     * - Includes functions to increase and decrease allowance as a workaround
     *   for the well-known issue with `approve`:
     *   https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     * - Allows for 'infinite allowance', where an allowance of 0xff..ff is not
     *   decreased by calls to transferFrom
     * - Lets a token holder use `transferFrom` to send their own tokens,
     *   without first setting allowance
     * - Emits 'Approval' events whenever allowance is changed by `transferFrom`
     * - Assigns infinite allowance for all token holders to the Vault
     */
    contract BalancerPoolToken is ERC20Permit {
        IVault private immutable _vault;
        constructor(
            string memory tokenName,
            string memory tokenSymbol,
            IVault vault
        ) ERC20(tokenName, tokenSymbol) ERC20Permit(tokenName) {
            _vault = vault;
        }
        function getVault() public view returns (IVault) {
            return _vault;
        }
        // Overrides
        /**
         * @dev Override to grant the Vault infinite allowance, causing for Pool Tokens to not require approval.
         *
         * This is sound as the Vault already provides authorization mechanisms when initiation token transfers, which this
         * contract inherits.
         */
        function allowance(address owner, address spender) public view override returns (uint256) {
            if (spender == address(getVault())) {
                return uint256(-1);
            } else {
                return super.allowance(owner, spender);
            }
        }
        /**
         * @dev Override to allow for 'infinite allowance' and let the token owner use `transferFrom` with no self-allowance
         */
        function transferFrom(
            address sender,
            address recipient,
            uint256 amount
        ) public override returns (bool) {
            uint256 currentAllowance = allowance(sender, msg.sender);
            _require(msg.sender == sender || currentAllowance >= amount, Errors.ERC20_TRANSFER_EXCEEDS_ALLOWANCE);
            _transfer(sender, recipient, amount);
            if (msg.sender != sender && currentAllowance != uint256(-1)) {
                // Because of the previous require, we know that if msg.sender != sender then currentAllowance >= amount
                _approve(sender, msg.sender, currentAllowance - amount);
            }
            return true;
        }
        /**
         * @dev Override to allow decreasing allowance by more than the current amount (setting it to zero)
         */
        function decreaseAllowance(address spender, uint256 amount) public override returns (bool) {
            uint256 currentAllowance = allowance(msg.sender, spender);
            if (amount >= currentAllowance) {
                _approve(msg.sender, spender, 0);
            } else {
                // No risk of underflow due to if condition
                _approve(msg.sender, spender, currentAllowance - amount);
            }
            return true;
        }
        // Internal functions
        function _mintPoolTokens(address recipient, uint256 amount) internal {
            _mint(recipient, amount);
        }
        function _burnPoolTokens(address sender, uint256 amount) internal {
            _burn(sender, amount);
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-interfaces/contracts/vault/IAuthorizer.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/helpers/Authentication.sol";
    /**
     * @dev Base authorization layer implementation for Pools.
     *
     * The owner account can call some of the permissioned functions - access control of the rest is delegated to the
     * Authorizer. Note that this owner is immutable: more sophisticated permission schemes, such as multiple ownership,
     * granular roles, etc., could be built on top of this by making the owner a smart contract.
     *
     * Access control of all other permissioned functions is delegated to an Authorizer. It is also possible to delegate
     * control of *all* permissioned functions to the Authorizer by setting the owner address to `_DELEGATE_OWNER`.
     */
    abstract contract BasePoolAuthorization is Authentication {
        address private immutable _owner;
        address private constant _DELEGATE_OWNER = 0xBA1BA1ba1BA1bA1bA1Ba1BA1ba1BA1bA1ba1ba1B;
        constructor(address owner) {
            _owner = owner;
        }
        function getOwner() public view returns (address) {
            return _owner;
        }
        function getAuthorizer() external view returns (IAuthorizer) {
            return _getAuthorizer();
        }
        function _canPerform(bytes32 actionId, address account) internal view override returns (bool) {
            if ((getOwner() != _DELEGATE_OWNER) && _isOwnerOnlyAction(actionId)) {
                // Only the owner can perform "owner only" actions, unless the owner is delegated.
                return msg.sender == getOwner();
            } else {
                // Non-owner actions are always processed via the Authorizer, as "owner only" ones are when delegated.
                return _getAuthorizer().canPerform(actionId, account, address(this));
            }
        }
        function _isOwnerOnlyAction(bytes32 actionId) internal view virtual returns (bool);
        function _getAuthorizer() internal view virtual returns (IAuthorizer);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    import "@balancer-labs/v2-interfaces/contracts/pool-utils/BasePoolUserData.sol";
    import "@balancer-labs/v2-interfaces/contracts/pool-utils/IRecoveryMode.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/math/FixedPoint.sol";
    import "./BasePoolAuthorization.sol";
    /**
     * @notice Handle storage and state changes for pools that support "Recovery Mode".
     *
     * @dev This is intended to provide a safe way to exit any pool during some kind of emergency, to avoid locking funds
     * in the event the pool enters a non-functional state (i.e., some code that normally runs during exits is causing
     * them to revert).
     *
     * Recovery Mode is *not* the same as pausing the pool. The pause function is only available during a short window
     * after factory deployment. Pausing can only be intentionally reversed during a buffer period, and the contract
     * will permanently unpause itself thereafter. Paused pools are completely disabled, in a kind of suspended animation,
     * until they are voluntarily or involuntarily unpaused.
     *
     * By contrast, a privileged account - typically a governance multisig - can place a pool in Recovery Mode at any
     * time, and it is always reversible. The pool is *not* disabled while in this mode: though of course whatever
     * condition prompted the transition to Recovery Mode has likely effectively disabled some functions. Rather,
     * a special "clean" exit is enabled, which runs the absolute minimum code necessary to exit proportionally.
     * In particular, stable pools do not attempt to compute the invariant (which is a complex, iterative calculation
     * that can fail in extreme circumstances), and no protocol fees are collected.
     *
     * It is critical to ensure that turning on Recovery Mode would do no harm, if activated maliciously or in error.
     */
    abstract contract RecoveryMode is IRecoveryMode, BasePoolAuthorization {
        using FixedPoint for uint256;
        using BasePoolUserData for bytes;
        /**
         * @dev Reverts if the contract is in Recovery Mode.
         */
        modifier whenNotInRecoveryMode() {
            _ensureNotInRecoveryMode();
            _;
        }
        /**
         * @notice Enable recovery mode, which enables a special safe exit path for LPs.
         * @dev Does not otherwise affect pool operations (beyond deferring payment of protocol fees), though some pools may
         * perform certain operations in a "safer" manner that is less likely to fail, in an attempt to keep the pool
         * running, even in a pathological state. Unlike the Pause operation, which is only available during a short window
         * after factory deployment, Recovery Mode can always be enabled.
         */
        function enableRecoveryMode() external override authenticate {
            _setRecoveryMode(true);
        }
        /**
         * @notice Disable recovery mode, which disables the special safe exit path for LPs.
         * @dev Protocol fees are not paid while in Recovery Mode, so it should only remain active for as long as strictly
         * necessary.
         *
         * This function will revert when called within a Vault context (i.e. in the middle of a join or an exit).
         *
         * This function depends on the invariant value, which may be calculated incorrectly in the middle of a join or
         * an exit, because the state of the pool could be out of sync with the state of the Vault.
         * `_onDisableRecoveryMode` will revert when called from such a context for weighted pools, effectively
         * protecting this function.
         *
         * See https://forum.balancer.fi/t/reentrancy-vulnerability-scope-expanded/4345 for reference.
         */
        function disableRecoveryMode() external override authenticate {
            _setRecoveryMode(false);
        }
        // Defer implementation for functions that require storage
        /**
         * @notice Override to check storage and return whether the pool is in Recovery Mode
         */
        function inRecoveryMode() public view virtual override returns (bool);
        /**
         * @dev Override to update storage and emit the event
         *
         * No complex code or external calls that could fail should be placed in the implementations,
         * which could jeopardize the ability to enable and disable Recovery Mode.
         */
        function _setRecoveryMode(bool enabled) internal virtual;
        /**
         * @dev Reverts if the contract is not in Recovery Mode.
         */
        function _ensureInRecoveryMode() internal view {
            _require(inRecoveryMode(), Errors.NOT_IN_RECOVERY_MODE);
        }
        /**
         * @dev Reverts if the contract is in Recovery Mode.
         */
        function _ensureNotInRecoveryMode() internal view {
            _require(!inRecoveryMode(), Errors.IN_RECOVERY_MODE);
        }
        /**
         * @dev A minimal proportional exit, suitable as is for most pools: though not for pools with preminted BPT
         * or other special considerations. Designed to be overridden if a pool needs to do extra processing,
         * such as scaling a stored invariant, or caching the new total supply.
         *
         * No complex code or external calls should be made in derived contracts that override this!
         */
        function _doRecoveryModeExit(
            uint256[] memory balances,
            uint256 totalSupply,
            bytes memory userData
        ) internal virtual returns (uint256, uint256[] memory) {
            uint256 bptAmountIn = userData.recoveryModeExit();
            uint256[] memory amountsOut = _computeProportionalAmountsOut(balances, totalSupply, bptAmountIn);
            return (bptAmountIn, amountsOut);
        }
        function _computeProportionalAmountsOut(
            uint256[] memory balances,
            uint256 totalSupply,
            uint256 bptAmountIn
        ) internal pure returns (uint256[] memory amountsOut) {
            /**********************************************************************************************
            // exactBPTInForTokensOut                                                                    //
            // (per token)                                                                               //
            // aO = tokenAmountOut             /        bptIn         \\                                  //
            // b = tokenBalance      a0 = b * | ---------------------  |                                 //
            // bptIn = bptAmountIn             \\     bptTotalSupply    /                                 //
            // bpt = bptTotalSupply                                                                      //
            **********************************************************************************************/
            // Since we're computing an amount out, we round down overall. This means rounding down on both the
            // multiplication and division.
            uint256 bptRatio = bptAmountIn.divDown(totalSupply);
            amountsOut = new uint256[](balances.length);
            for (uint256 i = 0; i < balances.length; i++) {
                amountsOut[i] = balances[i].mulDown(bptRatio);
            }
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    /**
     * @dev Wrappers over Solidity's arithmetic operations with added overflow
     * checks.
     *
     * Arithmetic operations in Solidity wrap on overflow. This can easily result
     * in bugs, because programmers usually assume that an overflow raises an
     * error, which is the standard behavior in high level programming languages.
     * `SafeMath` restores this intuition by reverting the transaction when an
     * operation overflows.
     *
     * Using this library instead of the unchecked operations eliminates an entire
     * class of bugs, so it's recommended to use it always.
     */
    library SafeMath {
        /**
         * @dev Returns the addition of two unsigned integers, reverting on
         * overflow.
         *
         * Counterpart to Solidity's `+` operator.
         *
         * Requirements:
         *
         * - Addition cannot overflow.
         */
        function add(uint256 a, uint256 b) internal pure returns (uint256) {
            uint256 c = a + b;
            _require(c >= a, Errors.ADD_OVERFLOW);
            return c;
        }
        /**
         * @dev Returns the subtraction of two unsigned integers, reverting on
         * overflow (when the result is negative).
         *
         * Counterpart to Solidity's `-` operator.
         *
         * Requirements:
         *
         * - Subtraction cannot overflow.
         */
        function sub(uint256 a, uint256 b) internal pure returns (uint256) {
            return sub(a, b, Errors.SUB_OVERFLOW);
        }
        /**
         * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
         * overflow (when the result is negative).
         *
         * Counterpart to Solidity's `-` operator.
         *
         * Requirements:
         *
         * - Subtraction cannot overflow.
         */
        function sub(
            uint256 a,
            uint256 b,
            uint256 errorCode
        ) internal pure returns (uint256) {
            _require(b <= a, errorCode);
            uint256 c = a - b;
            return c;
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/openzeppelin/IERC20Permit.sol";
    import "./ERC20.sol";
    import "../helpers/EOASignaturesValidator.sol";
    /**
     * @dev Implementation of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
     * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
     *
     * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
     * presenting a message signed by the account. By not relying on `{IERC20-approve}`, the token holder account doesn't
     * need to send a transaction, and thus is not required to hold Ether at all.
     *
     * _Available since v3.4._
     */
    abstract contract ERC20Permit is ERC20, IERC20Permit, EOASignaturesValidator {
        // solhint-disable-next-line var-name-mixedcase
        bytes32 private constant _PERMIT_TYPEHASH = keccak256(
            "Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)"
        );
        /**
         * @dev Initializes the {EIP712} domain separator using the `name` parameter, and setting `version` to `"1"`.
         *
         * It's a good idea to use the same `name` that is defined as the ERC20 token name.
         */
        constructor(string memory name) EIP712(name, "1") {
            // solhint-disable-previous-line no-empty-blocks
        }
        /**
         * @dev See {IERC20Permit-permit}.
         */
        function permit(
            address owner,
            address spender,
            uint256 value,
            uint256 deadline,
            uint8 v,
            bytes32 r,
            bytes32 s
        ) public virtual override {
            bytes32 structHash = keccak256(
                abi.encode(_PERMIT_TYPEHASH, owner, spender, value, getNextNonce(owner), deadline)
            );
            _ensureValidSignature(owner, structHash, _toArraySignature(v, r, s), deadline, Errors.INVALID_SIGNATURE);
            _approve(owner, spender, value);
        }
        /**
         * @dev See {IERC20Permit-nonces}.
         */
        function nonces(address owner) public view override returns (uint256) {
            return getNextNonce(owner);
        }
        /**
         * @dev See {IERC20Permit-DOMAIN_SEPARATOR}.
         */
        // solhint-disable-next-line func-name-mixedcase
        function DOMAIN_SEPARATOR() external view override returns (bytes32) {
            return getDomainSeparator();
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.7.0;
    /**
     * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
     * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
     *
     * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
     * presenting a message signed by the account. By not relying on `{IERC20-approve}`, the token holder account doesn't
     * need to send a transaction, and thus is not required to hold Ether at all.
     */
    interface IERC20Permit {
        /**
         * @dev Sets `value` as the allowance of `spender` over `owner`'s tokens,
         * given `owner`'s signed approval.
         *
         * IMPORTANT: The same issues {IERC20-approve} has related to transaction
         * ordering also apply here.
         *
         * Emits an {Approval} event.
         *
         * Requirements:
         *
         * - `spender` cannot be the zero address.
         * - `deadline` must be a timestamp in the future.
         * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
         * over the EIP712-formatted function arguments.
         * - the signature must use ``owner``'s current nonce (see {nonces}).
         *
         * For more information on the signature format, see the
         * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
         * section].
         */
        function permit(
            address owner,
            address spender,
            uint256 value,
            uint256 deadline,
            uint8 v,
            bytes32 r,
            bytes32 s
        ) external;
        /**
         * @dev Returns the current nonce for `owner`. This value must be
         * included whenever a signature is generated for {permit}.
         *
         * Every successful call to {permit} increases ``owner``'s nonce by one. This
         * prevents a signature from being used multiple times.
         */
        function nonces(address owner) external view returns (uint256);
        /**
         * @dev Returns the domain separator used in the encoding of the signature for `permit`, as defined by {EIP712}.
         */
        // solhint-disable-next-line func-name-mixedcase
        function DOMAIN_SEPARATOR() external view returns (bytes32);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/ISignaturesValidator.sol";
    import "../openzeppelin/EIP712.sol";
    /**
     * @dev Utility for signing Solidity function calls.
     */
    abstract contract EOASignaturesValidator is ISignaturesValidator, EIP712 {
        // Replay attack prevention for each account.
        mapping(address => uint256) internal _nextNonce;
        function getDomainSeparator() public view override returns (bytes32) {
            return _domainSeparatorV4();
        }
        function getNextNonce(address account) public view override returns (uint256) {
            return _nextNonce[account];
        }
        function _ensureValidSignature(
            address account,
            bytes32 structHash,
            bytes memory signature,
            uint256 errorCode
        ) internal {
            return _ensureValidSignature(account, structHash, signature, type(uint256).max, errorCode);
        }
        function _ensureValidSignature(
            address account,
            bytes32 structHash,
            bytes memory signature,
            uint256 deadline,
            uint256 errorCode
        ) internal {
            bytes32 digest = _hashTypedDataV4(structHash);
            _require(_isValidSignature(account, digest, signature), errorCode);
            // We could check for the deadline before validating the signature, but this leads to saner error processing (as
            // we only care about expired deadlines if the signature is correct) and only affects the gas cost of the revert
            // scenario, which will only occur infrequently, if ever.
            // The deadline is timestamp-based: it should not be relied upon for sub-minute accuracy.
            // solhint-disable-next-line not-rely-on-time
            _require(deadline >= block.timestamp, Errors.EXPIRED_SIGNATURE);
            // We only advance the nonce after validating the signature. This is irrelevant for this module, but it can be
            // important in derived contracts that override _isValidSignature (e.g. SignaturesValidator), as we want for
            // the observable state to still have the current nonce as the next valid one.
            _nextNonce[account] += 1;
        }
        function _isValidSignature(
            address account,
            bytes32 digest,
            bytes memory signature
        ) internal view virtual returns (bool) {
            _require(signature.length == 65, Errors.MALFORMED_SIGNATURE);
            bytes32 r;
            bytes32 s;
            uint8 v;
            // ecrecover takes the r, s and v signature parameters, and the only way to get them is to use assembly.
            // solhint-disable-next-line no-inline-assembly
            assembly {
                r := mload(add(signature, 0x20))
                s := mload(add(signature, 0x40))
                v := byte(0, mload(add(signature, 0x60)))
            }
            address recoveredAddress = ecrecover(digest, v, r, s);
            // ecrecover returns the zero address on recover failure, so we need to handle that explicitly.
            return (recoveredAddress != address(0) && recoveredAddress == account);
        }
        function _toArraySignature(
            uint8 v,
            bytes32 r,
            bytes32 s
        ) internal pure returns (bytes memory) {
            bytes memory signature = new bytes(65);
            // solhint-disable-next-line no-inline-assembly
            assembly {
                mstore(add(signature, 32), r)
                mstore(add(signature, 64), s)
                mstore8(add(signature, 96), v)
            }
            return signature;
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.7.0;
    /**
     * @dev https://eips.ethereum.org/EIPS/eip-712[EIP 712] is a standard for hashing and signing of typed structured data.
     *
     * The encoding specified in the EIP is very generic, and such a generic implementation in Solidity is not feasible,
     * thus this contract does not implement the encoding itself. Protocols need to implement the type-specific encoding
     * they need in their contracts using a combination of `abi.encode` and `keccak256`.
     *
     * This contract implements the EIP 712 domain separator ({_domainSeparatorV4}) that is used as part of the encoding
     * scheme, and the final step of the encoding to obtain the message digest that is then signed via ECDSA
     * ({_hashTypedDataV4}).
     *
     * The implementation of the domain separator was designed to be as efficient as possible while still properly updating
     * the chain id to protect against replay attacks on an eventual fork of the chain.
     *
     * NOTE: This contract implements the version of the encoding known as "v4", as implemented by the JSON RPC method
     * https://docs.metamask.io/guide/signing-data.html[`eth_signTypedDataV4` in MetaMask].
     *
     * _Available since v3.4._
     */
    abstract contract EIP712 {
        /* solhint-disable var-name-mixedcase */
        bytes32 private immutable _HASHED_NAME;
        bytes32 private immutable _HASHED_VERSION;
        bytes32 private immutable _TYPE_HASH;
        /* solhint-enable var-name-mixedcase */
        /**
         * @dev Initializes the domain separator and parameter caches.
         *
         * The meaning of `name` and `version` is specified in
         * https://eips.ethereum.org/EIPS/eip-712#definition-of-domainseparator[EIP 712]:
         *
         * - `name`: the user readable name of the signing domain, i.e. the name of the DApp or the protocol.
         * - `version`: the current major version of the signing domain.
         *
         * NOTE: These parameters cannot be changed except through a xref:learn::upgrading-smart-contracts.adoc[smart
         * contract upgrade].
         */
        constructor(string memory name, string memory version) {
            _HASHED_NAME = keccak256(bytes(name));
            _HASHED_VERSION = keccak256(bytes(version));
            _TYPE_HASH = keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)");
        }
        /**
         * @dev Returns the domain separator for the current chain.
         */
        function _domainSeparatorV4() internal view virtual returns (bytes32) {
            return keccak256(abi.encode(_TYPE_HASH, _HASHED_NAME, _HASHED_VERSION, _getChainId(), address(this)));
        }
        /**
         * @dev Given an already https://eips.ethereum.org/EIPS/eip-712#definition-of-hashstruct[hashed struct], this
         * function returns the hash of the fully encoded EIP712 message for this domain.
         *
         * This hash can be used together with {ECDSA-recover} to obtain the signer of a message. For example:
         *
         * ```solidity
         * bytes32 digest = _hashTypedDataV4(keccak256(abi.encode(
         *     keccak256("Mail(address to,string contents)"),
         *     mailTo,
         *     keccak256(bytes(mailContents))
         * )));
         * address signer = ECDSA.recover(digest, signature);
         * ```
         */
        function _hashTypedDataV4(bytes32 structHash) internal view virtual returns (bytes32) {
            return keccak256(abi.encodePacked("\\x19\\x01", _domainSeparatorV4(), structHash));
        }
        function _getChainId() private view returns (uint256 chainId) {
            // Silence state mutability warning without generating bytecode.
            // See https://github.com/ethereum/solidity/issues/10090#issuecomment-741789128 and
            // https://github.com/ethereum/solidity/issues/2691
            this;
            // solhint-disable-next-line no-inline-assembly
            assembly {
                chainId := chainid()
            }
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/IAuthentication.sol";
    /**
     * @dev Building block for performing access control on external functions.
     *
     * This contract is used via the `authenticate` modifier (or the `_authenticateCaller` function), which can be applied
     * to external functions to only make them callable by authorized accounts.
     *
     * Derived contracts must implement the `_canPerform` function, which holds the actual access control logic.
     */
    abstract contract Authentication is IAuthentication {
        bytes32 private immutable _actionIdDisambiguator;
        /**
         * @dev The main purpose of the `actionIdDisambiguator` is to prevent accidental function selector collisions in
         * multi contract systems.
         *
         * There are two main uses for it:
         *  - if the contract is a singleton, any unique identifier can be used to make the associated action identifiers
         *    unique. The contract's own address is a good option.
         *  - if the contract belongs to a family that shares action identifiers for the same functions, an identifier
         *    shared by the entire family (and no other contract) should be used instead.
         */
        constructor(bytes32 actionIdDisambiguator) {
            _actionIdDisambiguator = actionIdDisambiguator;
        }
        /**
         * @dev Reverts unless the caller is allowed to call this function. Should only be applied to external functions.
         */
        modifier authenticate() {
            _authenticateCaller();
            _;
        }
        /**
         * @dev Reverts unless the caller is allowed to call the entry point function.
         */
        function _authenticateCaller() internal view {
            bytes32 actionId = getActionId(msg.sig);
            _require(_canPerform(actionId, msg.sender), Errors.SENDER_NOT_ALLOWED);
        }
        function getActionId(bytes4 selector) public view override returns (bytes32) {
            // Each external function is dynamically assigned an action identifier as the hash of the disambiguator and the
            // function selector. Disambiguation is necessary to avoid potential collisions in the function selectors of
            // multiple contracts.
            return keccak256(abi.encodePacked(_actionIdDisambiguator, selector));
        }
        function _canPerform(bytes32 actionId, address user) internal view virtual returns (bool);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    library BasePoolUserData {
        // Special ExitKind for all pools, used in Recovery Mode. Use the max 8-bit value to prevent conflicts
        // with future additions to the ExitKind enums (or any front-end code that maps to existing values)
        uint8 public constant RECOVERY_MODE_EXIT_KIND = 255;
        // Return true if this is the special exit kind.
        function isRecoveryModeExitKind(bytes memory self) internal pure returns (bool) {
            // Check for the "no data" case, or abi.decode would revert
            return self.length > 0 && abi.decode(self, (uint8)) == RECOVERY_MODE_EXIT_KIND;
        }
        // Parse the bptAmountIn out of the userData
        function recoveryModeExit(bytes memory self) internal pure returns (uint256 bptAmountIn) {
            (, bptAmountIn) = abi.decode(self, (uint8, uint256));
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    /**
     * @dev Interface for the RecoveryMode module.
     */
    interface IRecoveryMode {
        /**
         * @dev Emitted when the Recovery Mode status changes.
         */
        event RecoveryModeStateChanged(bool enabled);
        /**
         * @notice Enables Recovery Mode in the Pool, disabling protocol fee collection and allowing for safe proportional
         * exits with low computational complexity and no dependencies.
         */
        function enableRecoveryMode() external;
        /**
         * @notice Disables Recovery Mode in the Pool, restoring protocol fee collection and disallowing proportional exits.
         */
        function disableRecoveryMode() external;
        /**
         * @notice Returns true if the Pool is in Recovery Mode.
         */
        function inRecoveryMode() external view returns (bool);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    interface IRateProvider {
        /**
         * @dev Returns an 18 decimal fixed point number that is the exchange rate of the token to some other underlying
         * token. The meaning of this rate depends on the context.
         */
        function getRate() external view returns (uint256);
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    import "@balancer-labs/v2-interfaces/contracts/standalone-utils/IProtocolFeePercentagesProvider.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/SafeCast.sol";
    import "../RecoveryMode.sol";
    /**
     * @dev The Vault does not provide the protocol swap fee percentage in swap hooks (as swaps don't typically need this
     * value), so for swaps that need this value, we would have to to fetch it ourselves from the
     * ProtocolFeePercentagesProvider. Additionally, other protocol fee types (such as Yield or AUM) can only be obtained
     * by making said call.
     *
     * However, these values change so rarely that it doesn't make sense to perform the required calls to get the current
     * values in every single user interaction. Instead, we keep a local copy that can be permissionlessly updated by anyone
     * with the real value. We also pack these values together, performing a single storage read to get them all.
     *
     * When initialized with a special sentinel value, the swap fee is delegated, meaning the mutable protocol swap fee
     * cache is set to the current value stored in the ProtocolFeePercentagesProvider, and can be updated by anyone with a
     * call to `updateProtocolFeePercentageCache`. Any other value means the protocol swap fee is fixed, so it is instead
     * stored in the immutable `_fixedProtocolSwapFeePercentage`.
     */
    abstract contract ProtocolFeeCache is RecoveryMode {
        using SafeCast for uint256;
        IProtocolFeePercentagesProvider private immutable _protocolFeeProvider;
        // Protocol Fee Percentages can never be larger than 100% (1e18), which fits in ~59 bits, so using 64 for each type
        // is sufficient.
        struct FeeTypeCache {
            uint64 swapFee;
            uint64 yieldFee;
            uint64 aumFee;
        }
        FeeTypeCache private _cache;
        event ProtocolFeePercentageCacheUpdated(uint256 indexed feeType, uint256 protocolFeePercentage);
        // Swap fees can be set to a fixed value at construction, or delegated to the ProtocolFeePercentagesProvider if
        // passing the special sentinel value.
        uint256 public constant DELEGATE_PROTOCOL_SWAP_FEES_SENTINEL = type(uint256).max;
        bool private immutable _delegatedProtocolSwapFees;
        // Only valid when `_delegatedProtocolSwapFees` is false
        uint256 private immutable _fixedProtocolSwapFeePercentage;
        constructor(IProtocolFeePercentagesProvider protocolFeeProvider, uint256 protocolSwapFeePercentage) {
            // Protocol swap fees are delegated to the value reported by the ProtocolFeePercentagesProvider if the sentinel
            // value is passed.
            bool delegatedProtocolSwapFees = protocolSwapFeePercentage == DELEGATE_PROTOCOL_SWAP_FEES_SENTINEL;
            _delegatedProtocolSwapFees = delegatedProtocolSwapFees;
            _protocolFeeProvider = protocolFeeProvider;
            _updateProtocolFeeCache(protocolFeeProvider, ProtocolFeeType.YIELD);
            _updateProtocolFeeCache(protocolFeeProvider, ProtocolFeeType.AUM);
            if (delegatedProtocolSwapFees) {
                _updateProtocolFeeCache(protocolFeeProvider, ProtocolFeeType.SWAP);
            } else {
                _require(
                    protocolSwapFeePercentage <= protocolFeeProvider.getFeeTypeMaximumPercentage(ProtocolFeeType.SWAP),
                    Errors.SWAP_FEE_PERCENTAGE_TOO_HIGH
                );
                // We cannot set `_fixedProtocolSwapFeePercentage` here due to it being immutable so instead we must set it
                // in the main function scope with a value based on whether protocol fees are delegated.
                // Emit an event as we do in `_updateProtocolFeeCache` to appear the same to offchain indexers.
                emit ProtocolFeePercentageCacheUpdated(ProtocolFeeType.SWAP, protocolSwapFeePercentage);
            }
            // As `_fixedProtocolSwapFeePercentage` is immutable we must set a value, but just set to zero if it's not used.
            _fixedProtocolSwapFeePercentage = delegatedProtocolSwapFees ? 0 : protocolSwapFeePercentage;
        }
        /**
         * @dev Returns the cached protocol fee percentage. If `getProtocolSwapFeeDelegation()` is false, this value is
         * immutable for swap fee queries. Alternatively, it will track the global fee percentage set in the
         * ProtocolFeePercentagesProvider.
         */
        function getProtocolFeePercentageCache(uint256 feeType) public view returns (uint256) {
            if (inRecoveryMode()) {
                return 0;
            }
            if (feeType == ProtocolFeeType.SWAP) {
                return getProtocolSwapFeeDelegation() ? _cache.swapFee : _fixedProtocolSwapFeePercentage;
            } else if (feeType == ProtocolFeeType.YIELD) {
                return _cache.yieldFee;
            } else if (feeType == ProtocolFeeType.AUM) {
                return _cache.aumFee;
            } else {
                _revert(Errors.UNHANDLED_FEE_TYPE);
            }
        }
        /**
         * @dev Can be called by anyone to update the cached fee percentages (swap fee is only updated when delegated).
         * Updates the cache to the latest value set by governance.
         *
         * This function will revert when called within a Vault context (i.e. in the middle of a join or an exit).
         *
         * This function depends on the invariant value, which may be calculated incorrectly in the middle of a join or
         * an exit, because the state of the pool could be out of sync with the state of the Vault.
         * `_beforeProtocolFeeCacheUpdate` will revert when called from such a context for weighted pools, effectively
         * protecting this function.
         *
         * See https://forum.balancer.fi/t/reentrancy-vulnerability-scope-expanded/4345 for reference.
         */
        function updateProtocolFeePercentageCache() external {
            _beforeProtocolFeeCacheUpdate();
            if (getProtocolSwapFeeDelegation()) {
                _updateProtocolFeeCache(_protocolFeeProvider, ProtocolFeeType.SWAP);
            }
            _updateProtocolFeeCache(_protocolFeeProvider, ProtocolFeeType.YIELD);
            _updateProtocolFeeCache(_protocolFeeProvider, ProtocolFeeType.AUM);
        }
        /**
         * @dev Override in derived contracts to perform some action before the cache is updated. This is typically relevant
         * to Pools that incur protocol debt between operations. To avoid altering the amount due retroactively, this debt
         * needs to be paid before the fee percentages change.
         */
        function _beforeProtocolFeeCacheUpdate() internal virtual {}
        /**
         * @dev Returns whether this Pool tracks protocol swap fee changes in the IProtocolFeePercentagesProvider.
         */
        function getProtocolSwapFeeDelegation() public view returns (bool) {
            return _delegatedProtocolSwapFees;
        }
        function _updateProtocolFeeCache(IProtocolFeePercentagesProvider protocolFeeProvider, uint256 feeType) private {
            uint256 currentValue = protocolFeeProvider.getFeeTypePercentage(feeType);
            if (feeType == ProtocolFeeType.SWAP) {
                _cache.swapFee = currentValue.toUint64();
            } else if (feeType == ProtocolFeeType.YIELD) {
                _cache.yieldFee = currentValue.toUint64();
            } else if (feeType == ProtocolFeeType.AUM) {
                _cache.aumFee = currentValue.toUint64();
            } else {
                _revert(Errors.UNHANDLED_FEE_TYPE);
            }
            emit ProtocolFeePercentageCacheUpdated(feeType, currentValue);
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-solidity-utils/contracts/math/FixedPoint.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/math/Math.sol";
    import "./ProtocolFees.sol";
    library InvariantGrowthProtocolSwapFees {
        using FixedPoint for uint256;
        function getProtocolOwnershipPercentage(
            uint256 invariantGrowthRatio,
            uint256 supplyGrowthRatio,
            uint256 protocolSwapFeePercentage
        ) internal pure returns (uint256) {
            // Joins and exits are symmetrical; for simplicity, we consider a join, where the invariant and supply
            // both increase.
            // |-------------------------|-- original invariant * invariantGrowthRatio
            // |   increase from fees    |
            // |-------------------------|-- original invariant * supply growth ratio (fee-less invariant)
            // |                         |
            // | increase from balances  |
            // |-------------------------|-- original invariant
            // |                         |
            // |                         |  |------------------|-- currentSupply
            // |                         |  |    BPT minted    |
            // |                         |  |------------------|-- previousSupply
            // |   original invariant    |  |  original supply |
            // |_________________________|  |__________________|
            //
            // If the join is proportional, the invariant and supply will likewise increase proportionally,
            // so the growth ratios (invariantGrowthRatio / supplyGrowthRatio) will be equal. In this case, we do not charge
            // any protocol fees.
            // We also charge no protocol fees in the case where `invariantGrowthRatio < supplyGrowthRatio` to avoid
            // potential underflows, however this should only occur in extremely low volume actions due solely to rounding
            // error.
            if ((supplyGrowthRatio >= invariantGrowthRatio) || (protocolSwapFeePercentage == 0)) return 0;
            // If the join is non-proportional, the supply increase will be proportionally less than the invariant increase,
            // since the BPT minted will be based on fewer tokens (because swap fees are not included). So the supply growth
            // is due entirely to the balance changes, while the invariant growth also includes swap fees.
            //
            // To isolate the amount of increase by fees then, we multiply the original invariant by the supply growth
            // ratio to get the "feeless invariant". The difference between the final invariant and this value is then
            // the amount of the invariant due to fees, which we convert to a percentage by normalizing against the
            // final invariant. This is expressed as the expression below:
            //
            // invariantGrowthFromFees = currentInvariant - supplyGrowthRatio * previousInvariant
            //
            // We then divide through by current invariant so the LHS can be identified as the fraction of the pool which
            // is made up of accumulated swap fees.
            //
            // swapFeesPercentage = 1 - supplyGrowthRatio * previousInvariant / currentInvariant
            //
            // We then define `invariantGrowthRatio` in a similar fashion to `supplyGrowthRatio` to give the result:
            //
            // swapFeesPercentage = 1 - supplyGrowthRatio / invariantGrowthRatio
            //
            // Using this form allows us to consider only the ratios of the two invariants, rather than their absolute
            // values: a useful property, as this is sometimes easier than calculating the full invariant twice.
            // We've already checked that `supplyGrowthRatio` is smaller than `invariantGrowthRatio`, and hence their ratio
            // smaller than FixedPoint.ONE, allowing for unchecked arithmetic.
            uint256 swapFeesPercentage = FixedPoint.ONE - supplyGrowthRatio.divDown(invariantGrowthRatio);
            // We then multiply by the protocol swap fee percentage to get the fraction of the pool which the protocol
            // should own once fees have been collected.
            return swapFeesPercentage.mulDown(protocolSwapFeePercentage);
        }
        function calcDueProtocolFees(
            uint256 invariantGrowthRatio,
            uint256 previousSupply,
            uint256 currentSupply,
            uint256 protocolSwapFeePercentage
        ) internal pure returns (uint256) {
            uint256 protocolOwnershipPercentage = getProtocolOwnershipPercentage(
                invariantGrowthRatio,
                currentSupply.divDown(previousSupply),
                protocolSwapFeePercentage
            );
            return ProtocolFees.bptForPoolOwnershipPercentage(currentSupply, protocolOwnershipPercentage);
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    /**
     * @dev Source of truth for all Protocol Fee percentages, that is, how much the protocol charges certain actions. Some
     * of these values may also be retrievable from other places (such as the swap fee percentage), but this is the
     * preferred source nonetheless.
     */
    interface IProtocolFeePercentagesProvider {
        // All fee percentages are 18-decimal fixed point numbers, so e.g. 1e18 = 100% and 1e16 = 1%.
        // Emitted when a new fee type is registered.
        event ProtocolFeeTypeRegistered(uint256 indexed feeType, string name, uint256 maximumPercentage);
        // Emitted when the value of a fee type changes.
        // IMPORTANT: it is possible for a third party to modify the SWAP and FLASH_LOAN fee type values directly in the
        // ProtocolFeesCollector, which will result in this event not being emitted despite their value changing. Such usage
        // of the ProtocolFeesCollector is however discouraged: all state-changing interactions with it should originate in
        // this contract.
        event ProtocolFeePercentageChanged(uint256 indexed feeType, uint256 percentage);
        /**
         * @dev Registers a new fee type in the system, making it queryable via `getFeeTypePercentage` and `getFeeTypeName`,
         * as well as configurable via `setFeeTypePercentage`.
         *
         * `feeType` can be any arbitrary value (that is not in use).
         *
         * It is not possible to de-register fee types, nor change their name or maximum value.
         */
        function registerFeeType(
            uint256 feeType,
            string memory name,
            uint256 maximumValue,
            uint256 initialValue
        ) external;
        /**
         * @dev Returns true if `feeType` has been registered and can be queried.
         */
        function isValidFeeType(uint256 feeType) external view returns (bool);
        /**
         * @dev Returns true if `value` is a valid percentage value for `feeType`.
         */
        function isValidFeeTypePercentage(uint256 feeType, uint256 value) external view returns (bool);
        /**
         * @dev Sets the percentage value for `feeType` to `newValue`.
         *
         * IMPORTANT: it is possible for a third party to modify the SWAP and FLASH_LOAN fee type values directly in the
         * ProtocolFeesCollector, without invoking this function. This will result in the `ProtocolFeePercentageChanged`
         * event not being emitted despite their value changing. Such usage of the ProtocolFeesCollector is however
         * discouraged: only this contract should be granted permission to call `setSwapFeePercentage` and
         * `setFlashLoanFeePercentage`.
         */
        function setFeeTypePercentage(uint256 feeType, uint256 newValue) external;
        /**
         * @dev Returns the current percentage value for `feeType`. This is the preferred mechanism for querying these -
         * whenever possible, use this fucntion instead of e.g. querying the ProtocolFeesCollector.
         */
        function getFeeTypePercentage(uint256 feeType) external view returns (uint256);
        /**
         * @dev Returns `feeType`'s maximum value.
         */
        function getFeeTypeMaximumPercentage(uint256 feeType) external view returns (uint256);
        /**
         * @dev Returns `feeType`'s name.
         */
        function getFeeTypeName(uint256 feeType) external view returns (string memory);
    }
    library ProtocolFeeType {
        // This list is not exhaustive - more fee types can be added to the system. It is expected for this list to be
        // extended with new fee types as they are registered, to keep them all in one place and reduce
        // likelihood of user error.
        // solhint-disable private-vars-leading-underscore
        uint256 internal constant SWAP = 0;
        uint256 internal constant FLASH_LOAN = 1;
        uint256 internal constant YIELD = 2;
        uint256 internal constant AUM = 3;
        // solhint-enable private-vars-leading-underscore
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    /**
     * @dev Wrappers over Solidity's uintXX/intXX casting operators with added overflow
     * checks.
     *
     * Downcasting from uint256/int256 in Solidity does not revert on overflow. This can
     * easily result in undesired exploitation or bugs, since developers usually
     * assume that overflows raise errors. `SafeCast` restores this intuition by
     * reverting the transaction when such an operation overflows.
     *
     * Using this library instead of the unchecked operations eliminates an entire
     * class of bugs, so it's recommended to use it always.
     *
     * Can be combined with {SafeMath} and {SignedSafeMath} to extend it to smaller types, by performing
     * all math on `uint256` and `int256` and then downcasting.
     */
    library SafeCast {
        /**
         * @dev Converts an unsigned uint256 into a signed int256.
         *
         * Requirements:
         *
         * - input must be less than or equal to maxInt256.
         */
        function toInt256(uint256 value) internal pure returns (int256) {
            _require(value >> 255 == 0, Errors.SAFE_CAST_VALUE_CANT_FIT_INT256);
            return int256(value);
        }
        /**
         * @dev Converts an unsigned uint256 into an unsigned uint64.
         *
         * Requirements:
         *
         * - input must be less than or equal to maxUint64.
         */
        function toUint64(uint256 value) internal pure returns (uint64) {
            _require(value <= type(uint64).max, Errors.SAFE_CAST_VALUE_CANT_FIT_UINT64);
            return uint64(value);
        }
    }
    // SPDX-License-Identifier: GPL-3.0-or-later
    // This program is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    // You should have received a copy of the GNU General Public License
    // along with this program.  If not, see <http://www.gnu.org/licenses/>.
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-solidity-utils/contracts/math/FixedPoint.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/math/Math.sol";
    library ProtocolFees {
        using FixedPoint for uint256;
        /**
         * @dev Calculates the amount of BPT necessary to give ownership of a given percentage of the Pool.
         * Note that this function reverts if `poolPercentage` >= 100%, it's expected that the caller will enforce this.
         * @param totalSupply - The total supply of the pool prior to minting BPT.
         * @param poolOwnershipPercentage - The desired ownership percentage of the pool to have as a result of minting BPT.
         * @return bptAmount - The amount of BPT to mint such that it is `poolPercentage` of the resultant total supply.
         */
        function bptForPoolOwnershipPercentage(uint256 totalSupply, uint256 poolOwnershipPercentage)
            internal
            pure
            returns (uint256)
        {
            // If we mint some amount `bptAmount` of BPT then the percentage ownership of the pool this grants is given by:
            // `poolOwnershipPercentage = bptAmount / (totalSupply + bptAmount)`.
            // Solving for `bptAmount`, we arrive at:
            // `bptAmount = totalSupply * poolOwnershipPercentage / (1 - poolOwnershipPercentage)`.
            return Math.divDown(Math.mul(totalSupply, poolOwnershipPercentage), poolOwnershipPercentage.complement());
        }
    }