ETH Price: $2,664.97 (+8.51%)

Transaction Decoder

Block:
22296040 at Apr-18-2025 12:59:47 PM +UTC
Transaction Fee:
0.000053556362831483 ETH $0.14
Gas Used:
43,691 Gas / 1.225798513 Gwei

Account State Difference:

  Address   Before After State Difference Code
0x13434606...E8B712361
0.123883326637536625 Eth
Nonce: 48
0.123829770274705142 Eth
Nonce: 49
0.000053556362831483
(Titan Builder)
5.036771893988476965 Eth5.036793739488476965 Eth0.0000218455

Execution Trace

Vault.exitPool( poolId=5EE945D9BFA5AD48C64FC7ACFED497D3546C0D03000200000000000000000000, sender=0x6f198139B06D312E05b602489eDffB44c5621Fe0, recipient=0x6f198139B06D312E05b602489eDffB44c5621Fe0, request=[{name:assets, type:address[], order:1, indexed:false, value:[0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48, 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2], valueString:[0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48, 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2]}, {name:minAmountsOut, type:uint256[], order:2, indexed:false, value:[515687123, 225296892958891887], valueString:[515687123, 225296892958891887]}, {name:userData, type:bytes, order:3, indexed:false, value:0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000F68E7DE8211A9E8316, valueString:0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000F68E7DE8211A9E8316}, {name:toInternalBalance, type:bool, order:4, indexed:false, value:false, valueString:False}] )
  • Authorizer.canPerform( actionId=2A4933A6914916D9DCF1F08473DCE094C2FF15177BED9C663A26E6C63477FD0D, account=0x1343460682d3dBcc7F6aeAc74F209e1E8B712361, 0xd315a9C38eC871068FEC378E4Ce78AF528C76293 ) => ( False )
    File 1 of 2: 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 <0.9.0;
    // 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;
        uint256 internal constant INSUFFICIENT_DATA = 105;
        // 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;
        uint256 internal constant ADD_OR_REMOVE_BPT = 354;
        uint256 internal constant INVALID_CIRCUIT_BREAKER_BOUNDS = 355;
        uint256 internal constant CIRCUIT_BREAKER_TRIPPED = 356;
        uint256 internal constant MALICIOUS_QUERY_REVERT = 357;
        uint256 internal constant JOINS_EXITS_DISABLED = 358;
        // 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;
        uint256 internal constant BURN_FROM_ZERO = 444;
        // 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;
        // FeeSplitter
        uint256 internal constant SPLITTER_FEE_PERCENTAGE_TOO_HIGH = 700;
        // Misc
        uint256 internal constant UNIMPLEMENTED = 998;
        uint256 internal constant SHOULD_NOT_HAPPEN = 999;
    }
    // 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 <0.9.0;
    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 <0.9.0;
    /**
     * @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 <0.9.0;
    /**
     * @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 <0.9.0;
    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: MIT
    pragma solidity >=0.7.0 <0.9.0;
    /**
     * @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 <0.9.0;
    /**
     * @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 <0.9.0;
    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 <0.9.0;
    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 solidity >=0.7.0 <0.9.0;
    // 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 <0.9.0;
    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 <0.9.0;
    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 <0.9.0;
    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 <0.9.0;
    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 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 <0.9.0;
    /**
     * @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;
    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;
    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: 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 "./EOASignaturesValidator.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 `_entrypointTypeHash` function to map function selectors to EIP712 structs.
     */
    abstract contract ExtraCalldataEOASignaturesValidator is EOASignaturesValidator {
        // 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;
        /**
         * @dev Reverts with `errorCode` unless a valid signature for `user` was appended to the calldata.
         */
        function _validateExtraCalldataSignature(address user, uint256 errorCode) internal {
            bytes32 typeHash = _entrypointTypeHash();
            // Prevent accidental signature validation for functions that don't have an associated type hash.
            _require(typeHash != bytes32(0), errorCode);
            uint256 deadline = _deadline();
            // All type hashes have this format: (bytes calldata, address sender, uint256 nonce, uint256 deadline).
            bytes32 structHash = keccak256(
                abi.encode(typeHash, keccak256(_calldata()), msg.sender, getNextNonce(user), deadline)
            );
            _ensureValidSignature(user, structHash, _signature(), deadline, errorCode);
        }
        /**
         * @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 _entrypointTypeHash() 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 (bytes memory) {
            // v, r and s are appended after the signature deadline, in that order.
            uint8 v = uint8(uint256(_decodeExtraCalldataWord(0x20)));
            bytes32 r = _decodeExtraCalldataWord(0x40);
            bytes32 s = _decodeExtraCalldataWord(0x60);
            return _toArraySignature(v, r, s);
        }
        /**
         * @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: 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;
    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 immutable _pauseWindowEndTime;
        uint256 private immutable _bufferPeriodEndTime;
        bool private _paused;
        constructor(uint256 pauseWindowDuration, uint256 bufferPeriodDuration) {
            _require(pauseWindowDuration <= PausableConstants.MAX_PAUSE_WINDOW_DURATION, Errors.MAX_PAUSE_WINDOW_DURATION);
            _require(
                bufferPeriodDuration <= PausableConstants.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;
        }
    }
    /**
     * @dev Keep the maximum durations in a single place.
     */
    library PausableConstants {
        uint256 public constant MAX_PAUSE_WINDOW_DURATION = 270 days;
        uint256 public constant MAX_BUFFER_PERIOD_DURATION = 90 days;
    }
    // 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 {
        // solhint-disable no-inline-assembly
        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 result) {
            uint256 product = a * b;
            _require(a == 0 || product / a == b, Errors.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, if x == 0 then the result is zero
            //
            // Equivalent to:
            // result = product == 0 ? 0 : ((product - 1) / FixedPoint.ONE) + 1;
            assembly {
                result := mul(iszero(iszero(product)), add(div(sub(product, 1), ONE), 1))
            }
        }
        function divDown(uint256 a, uint256 b) internal pure returns (uint256) {
            _require(b != 0, Errors.ZERO_DIVISION);
            uint256 aInflated = a * ONE;
            _require(a == 0 || aInflated / a == ONE, Errors.DIV_INTERNAL); // mul overflow
            return aInflated / b;
        }
        function divUp(uint256 a, uint256 b) internal pure returns (uint256 result) {
            _require(b != 0, Errors.ZERO_DIVISION);
            uint256 aInflated = a * ONE;
            _require(a == 0 || 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, if x == 0 then the result is zero
            //
            // Equivalent to:
            // result = a == 0 ? 0 : (a * FixedPoint.ONE - 1) / b + 1;
            assembly {
                result := mul(iszero(iszero(aInflated)), add(div(sub(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 result) {
            // Equivalent to:
            // result = (x < ONE) ? (ONE - x) : 0;
            assembly {
                result := mul(lt(x, ONE), sub(ONE, x))
            }
        }
    }
    // 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: 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 {
        // solhint-disable no-inline-assembly
        /**
         * @dev Returns the absolute value of a signed integer.
         */
        function abs(int256 a) internal pure returns (uint256 result) {
            // Equivalent to:
            // result = a > 0 ? uint256(a) : uint256(-a)
            assembly {
                let s := sar(255, a)
                result := sub(xor(a, s), s)
            }
        }
        /**
         * @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 result) {
            // Equivalent to:
            // result = (a < b) ? b : a;
            assembly {
                result := sub(a, mul(sub(a, b), lt(a, b)))
            }
        }
        /**
         * @dev Returns the smallest of two numbers of 256 bits.
         */
        function min(uint256 a, uint256 b) internal pure returns (uint256 result) {
            // Equivalent to `result = (a < b) ? a : b`
            assembly {
                result := sub(a, mul(sub(a, b), gt(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 result) {
            _require(b != 0, Errors.ZERO_DIVISION);
            // Equivalent to:
            // result = a == 0 ? 0 : 1 + (a - 1) / b;
            assembly {
                result := mul(iszero(iszero(a)), add(1, div(sub(a, 1), b)))
            }
        }
    }
    // SPDX-License-Identifier: MIT
    // Based on the Address library from OpenZeppelin Contracts, altered by removing the `isContract` checks on
    // `functionCall` and `functionDelegateCall` in order to save gas, as the recipients are known to be contracts.
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/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;
        }
        // solhint-disable max-line-length
        /**
         * @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);
        }
        /**
         * @dev Performs a Solidity function call using a low level `call`. A
         * plain `call` is an unsafe replacement for a function call: use this
         * function instead.
         *
         * If `target` reverts with a revert reason, it is bubbled up by this
         * function (like regular Solidity function calls).
         *
         * Returns the raw returned data. To convert to the expected return value,
         * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
         *
         * Requirements:
         *
         * - calling `target` with `data` must not revert.
         *
         * _Available since v3.1._
         */
        function functionCall(address target, bytes memory data) internal returns (bytes memory) {
            // solhint-disable-next-line avoid-low-level-calls
            (bool success, bytes memory returndata) = target.call(data);
            return verifyCallResult(success, returndata);
        }
        // solhint-enable max-line-length
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
         * but passing some native ETH as msg.value to the call.
         *
         * _Available since v3.4._
         */
        function functionCallWithValue(
            address target,
            bytes memory data,
            uint256 value
        ) internal returns (bytes memory) {
            // solhint-disable-next-line avoid-low-level-calls
            (bool success, bytes memory returndata) = target.call{ value: value }(data);
            return verifyCallResult(success, returndata);
        }
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
         * but performing a delegate call.
         *
         * _Available since v3.4._
         */
        function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
            // solhint-disable-next-line avoid-low-level-calls
            (bool success, bytes memory returndata) = target.delegatecall(data);
            return verifyCallResult(success, returndata);
        }
        /**
         * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling up the
         * revert reason or using the one provided.
         *
         * _Available since v4.3._
         */
        function verifyCallResult(bool success, bytes memory returndata) internal pure returns (bytes memory) {
            if (success) {
                return returndata;
            } else {
                // Look for revert reason and bubble it up if present
                if (returndata.length > 0) {
                    // The easiest way to bubble the revert reason is using memory via assembly
                    // solhint-disable-next-line no-inline-assembly
                    assembly {
                        let returndata_size := mload(returndata)
                        revert(add(32, returndata), returndata_size)
                    }
                } else {
                    _revert(Errors.LOW_LEVEL_CALL_FAILED);
                }
            }
        }
    }
    // 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));
        }
        // solc-ignore-next-line func-mutability
        function _getChainId() private view returns (uint256 chainId) {
            // solhint-disable-next-line no-inline-assembly
            assembly {
                chainId := chainid()
            }
        }
    }
    // SPDX-License-Identifier: MIT
    // 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
    //  * indexOf, 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.
    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";
    /**
     * @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 and IERC20ToUint256Map, resulting in more dense bytecode (as long as each contract only uses
        // one of these - there'll otherwise be duplicated code).
        // IERC20ToBytes32Map
        // solhint-disable func-name-mixedcase
        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;
                // The swap is only necessary if we're not removing the last element
                if (toDeleteIndex != lastIndex) {
                    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`.
         *
         * Requirements:
         *
         * - `key` must be in the map.
         */
        function indexOf(
            IERC20ToBytes32Map storage map,
            IERC20 key,
            uint256 errorCode
        ) internal view returns (uint256) {
            uint256 uncheckedIndex = unchecked_indexOf(map, key);
            _require(uncheckedIndex != 0, errorCode);
            return uncheckedIndex - 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];
        }
        // IERC20ToUint256Map
        struct IERC20ToUint256MapEntry {
            IERC20 _key;
            uint256 _value;
        }
        struct IERC20ToUint256Map {
            // Number of entries in the map
            uint256 _length;
            // Storage of map keys and values
            mapping(uint256 => IERC20ToUint256MapEntry) _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(
            IERC20ToUint256Map storage map,
            IERC20 key,
            uint256 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] = IERC20ToUint256MapEntry({ _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(
            IERC20ToUint256Map storage map,
            uint256 index,
            uint256 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(IERC20ToUint256Map 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;
                // The swap is only necessary if we're not removing the last element
                if (toDeleteIndex != lastIndex) {
                    IERC20ToUint256MapEntry 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(IERC20ToUint256Map 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(IERC20ToUint256Map 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(IERC20ToUint256Map storage map, uint256 index) internal view returns (IERC20, uint256) {
            _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(IERC20ToUint256Map storage map, uint256 index) internal view returns (IERC20, uint256) {
            IERC20ToUint256MapEntry 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(IERC20ToUint256Map storage map, uint256 index) internal view returns (uint256) {
            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(
            IERC20ToUint256Map storage map,
            IERC20 key,
            uint256 errorCode
        ) internal view returns (uint256) {
            uint256 index = map._indexes[key];
            _require(index > 0, errorCode);
            return unchecked_valueAt(map, index - 1);
        }
        /**
         * @dev Returns the index for `key`.
         *
         * Requirements:
         *
         * - `key` must be in the map.
         */
        function indexOf(
            IERC20ToUint256Map storage map,
            IERC20 key,
            uint256 errorCode
        ) internal view returns (uint256) {
            uint256 uncheckedIndex = unchecked_indexOf(map, key);
            _require(uncheckedIndex != 0, errorCode);
            return uncheckedIndex - 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(IERC20ToUint256Map storage map, IERC20 key) internal view returns (uint256) {
            return map._indexes[key];
        }
    }
    // SPDX-License-Identifier: MIT
    // 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 and bytes32 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.
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    /**
     * @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, 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;
                // The swap is only necessary if we're not removing the last element
                if (toDeleteIndex != lastIndex) {
                    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.
         */
        // solhint-disable-next-line func-name-mixedcase
        function unchecked_at(AddressSet storage set, uint256 index) internal view returns (address) {
            return set._values[index];
        }
        function rawIndexOf(AddressSet storage set, address value) internal view returns (uint256) {
            return set._indexes[value] - 1;
        }
        struct Bytes32Set {
            // Storage of set values
            bytes32[] _values;
            // Position of the value in the `values` array, plus 1 because index 0
            // means a value is not in the set.
            mapping(bytes32 => 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(Bytes32Set storage set, bytes32 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(Bytes32Set storage set, bytes32 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;
                // The swap is only necessary if we're not removing the last element
                if (toDeleteIndex != lastIndex) {
                    bytes32 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(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
            return set._indexes[value] != 0;
        }
        /**
         * @dev Returns the number of values on the set. O(1).
         */
        function length(Bytes32Set 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(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
            _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.
         */
        // solhint-disable-next-line func-name-mixedcase
        function unchecked_at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
            return set._values[index];
        }
        function rawIndexOf(Bytes32Set storage set, bytes32 value) internal view returns (uint256) {
            return set._indexes[value] - 1;
        }
    }
    // SPDX-License-Identifier: MIT
    // 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.
    pragma solidity ^0.7.0;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    /**
     * @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: 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: MIT
    // Based on the ReentrancyGuard library from OpenZeppelin Contracts, altered to reduce gas costs.
    // The `safeTransfer` and `safeTransferFrom` functions assume that `token` is a contract (an account with code), and
    // work differently from the OpenZeppelin version if it is not.
    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";
    /**
     * @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 safeApprove(
            IERC20 token,
            address to,
            uint256 value
        ) internal {
            // Some contracts need their allowance reduced to 0 before setting it to an arbitrary amount.
            if (value != 0 && token.allowance(address(this), address(to)) != 0) {
                _callOptionalReturn(address(token), abi.encodeWithSelector(token.approve.selector, to, 0));
            }
            _callOptionalReturn(address(token), abi.encodeWithSelector(token.approve.selector, to, value));
        }
        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.
            // solhint-disable-next-line avoid-low-level-calls
            (bool success, bytes memory returndata) = token.call(data);
            // If the low-level call didn't succeed we return whatever was returned from it.
            // solhint-disable-next-line no-inline-assembly
            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;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/openzeppelin/IERC20.sol";
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/misc/IWETH.sol";
    import "@balancer-labs/v2-interfaces/contracts/vault/IAsset.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: 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/solidity-utils/helpers/BalancerErrors.sol";
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/openzeppelin/IERC20.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/ReentrancyGuard.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/SafeERC20.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/helpers/InputHelpers.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/math/Math.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 "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/openzeppelin/IERC20.sol";
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/misc/IWETH.sol";
    import "@balancer-labs/v2-interfaces/contracts/vault/IAsset.sol";
    import "@balancer-labs/v2-interfaces/contracts/vault/IVault.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/SafeERC20.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/Address.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/math/Math.sol";
    import "./AssetHelpers.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 "@balancer-labs/v2-solidity-utils/contracts/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;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/openzeppelin/IERC20.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/EnumerableMap.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 "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/openzeppelin/IERC20.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/EnumerableSet.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 "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/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 "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/openzeppelin/IERC20.sol";
    import "@balancer-labs/v2-interfaces/contracts/vault/IVault.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/ReentrancyGuard.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/math/FixedPoint.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/SafeERC20.sol";
    import "./ProtocolFeesCollector.sol";
    import "./VaultAuthorization.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 (IProtocolFeesCollector) {
            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/>.
    // 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 "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/openzeppelin/IERC20.sol";
    import "@balancer-labs/v2-interfaces/contracts/vault/IFlashLoanRecipient.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/ReentrancyGuard.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/SafeERC20.sol";
    import "./Fees.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 "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/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;
    pragma experimental ABIEncoderV2;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/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 "@balancer-labs/v2-interfaces/contracts/vault/IProtocolFeesCollector.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/ReentrancyGuard.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/helpers/InputHelpers.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/helpers/Authentication.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/SafeERC20.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 IProtocolFeesCollector, 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 override 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;
        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 override 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 override authenticate {
            _require(newSwapFeePercentage <= _MAX_PROTOCOL_SWAP_FEE_PERCENTAGE, Errors.SWAP_FEE_PERCENTAGE_TOO_HIGH);
            _swapFeePercentage = newSwapFeePercentage;
            emit SwapFeePercentageChanged(newSwapFeePercentage);
        }
        function setFlashLoanFeePercentage(uint256 newFlashLoanFeePercentage) external override 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 override returns (uint256) {
            return _swapFeePercentage;
        }
        function getFlashLoanFeePercentage() external view override returns (uint256) {
            return _flashLoanFeePercentage;
        }
        function getCollectedFeeAmounts(IERC20[] memory tokens)
            external
            view
            override
            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 override 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;
    pragma experimental ABIEncoderV2;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/openzeppelin/IERC20.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/ReentrancyGuard.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/SafeCast.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/SafeERC20.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/math/Math.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 "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    import "@balancer-labs/v2-interfaces/contracts/vault/IVault.sol";
    import "@balancer-labs/v2-interfaces/contracts/vault/IAuthorizer.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/helpers/Authentication.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/helpers/ExtraCalldataEOASignaturesValidator.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/helpers/TemporarilyPausable.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/ReentrancyGuard.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,
        ExtraCalldataEOASignaturesValidator,
        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))))
            EIP712("Balancer V2 Vault", "1")
        {
            _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)) {
                    _validateExtraCalldataSignature(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 _entrypointTypeHash() 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/>.
    pragma solidity ^0.7.0;
    pragma experimental ABIEncoderV2;
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/openzeppelin/IERC20.sol";
    import "@balancer-labs/v2-interfaces/contracts/vault/IBasePool.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/ReentrancyGuard.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/helpers/InputHelpers.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/SafeERC20.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/math/Math.sol";
    import "@balancer-labs/v2-vault/contracts/Fees.sol";
    import "@balancer-labs/v2-vault/contracts/PoolTokens.sol";
    import "@balancer-labs/v2-vault/contracts/UserBalance.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 corresponding Pool hook is called to get the amounts in/out plus protocol fee amounts.
            (
                uint256[] memory amountsInOrOut,
                uint256[] memory dueProtocolFeeAmounts
            ) = _callPoolBalanceChange(kind, poolId, sender, recipient, change, balances);
            // We update the Pool balances based on the amounts in/out and fees paid.
            _updatePoolBalances(kind, poolId, sender, change, tokens, balances, amountsInOrOut, dueProtocolFeeAmounts);
           
            // We handle the necessary transfers and fee payments. 
            kind == PoolBalanceChangeKind.JOIN
                ? _processJoinPoolTransfers(sender, change, balances, amountsInOrOut, dueProtocolFeeAmounts)
                : _processExitPoolTransfers(recipient, change, balances, amountsInOrOut, dueProtocolFeeAmounts);
        }
        /**
         * @dev Calls the corresponding Pool hook to get the amounts in/out plus protocol fee amounts, and returns them.
         */
        function _callPoolBalanceChange(
            PoolBalanceChangeKind kind,
            bytes32 poolId,
            address sender,
            address payable recipient,
            PoolBalanceChange memory change,
            bytes32[] memory balances
        )
            private
            returns (
                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);
        }
        /**
         * @dev Updates the Pool balances based on the amounts in/out and fees paid.
         */
        function _updatePoolBalances(
            PoolBalanceChangeKind kind,
            bytes32 poolId,
            address sender,
            PoolBalanceChange memory change,
            IERC20[] memory tokens,
            bytes32[] memory balances,
            uint256[] memory amountsInOrOut,
            uint256[] memory dueProtocolFeeAmounts
        ) private {
            bytes32[] memory finalBalances = kind == PoolBalanceChangeKind.JOIN
                ? _computeJoinPoolFinalBalances(balances, change.limits, amountsInOrOut, dueProtocolFeeAmounts)
                : _computeExitPoolFinalBalances(balances, change.limits, amountsInOrOut, dueProtocolFeeAmounts);
            // 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),
                dueProtocolFeeAmounts
            );
        
        }
        /**
         * @dev Computes the final balances for a Pool join, which are the current balances plus `amountsIn` minus
         * accumulated protocol swap fees.
         */
        function _computeJoinPoolFinalBalances(
            bytes32[] memory balances,
            uint256[] memory maxAmountsIn,
            uint256[] memory amountsIn,
            uint256[] memory dueProtocolFeeAmounts
        ) private view returns (bytes32[] memory finalBalances) {
            
            uint256 length = balances.length;
            finalBalances = new bytes32[](length);
            for (uint256 i; i < length; ++i) {
                uint256 amountIn = amountsIn[i];
                _require(amountIn <= maxAmountsIn[i], Errors.JOIN_ABOVE_MAX);
                uint256 feeAmount = dueProtocolFeeAmounts[i];
                // 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);
            }
        }
        /**
         * @dev Computes the final balances for a Pool exit, which are the current balances minus `amountsOut` and fees
         * paid (`dueProtocolFeeAmounts`).
         */
        function _computeExitPoolFinalBalances(
            bytes32[] memory balances,
            uint256[] memory minAmountsOut,
            uint256[] memory amountsOut,
            uint256[] memory dueProtocolFeeAmounts
        ) private view returns (bytes32[] memory finalBalances) {
            uint256 length = balances.length;
            finalBalances = new bytes32[](length);
            for (uint256 i; i < length; ++i) {
                uint256 amountOut = amountsOut[i];
                _require(amountOut >= minAmountsOut[i], Errors.EXIT_BELOW_MIN);
                uint256 feeAmount = dueProtocolFeeAmounts[i];
                // 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 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 {
            // We need to track how much of the received ETH was used and wrapped into WETH to return any excess.
            uint256 wrappedEth;
            
            // change.assets.length == balances.length
            uint256 length = balances.length;
            for (uint256 i; i < length; ++i) {
                uint256 amountIn = amountsIn[i];
                // 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);
            }
            // 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 {
            
            uint256 length = balances.length;
            for (uint256 i; i < length; ++i) {
                uint256 amountOut = amountsOut[i];
                // 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);
            }
        }
        /**
         * @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; 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; 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 "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
    import "@balancer-labs/v2-interfaces/contracts/solidity-utils/openzeppelin/IERC20.sol";
    import "@balancer-labs/v2-interfaces/contracts/vault/IPoolSwapStructs.sol";
    import "@balancer-labs/v2-interfaces/contracts/vault/IGeneralPool.sol";
    import "@balancer-labs/v2-interfaces/contracts/vault/IMinimalSwapInfoPool.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/EnumerableSet.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/ReentrancyGuard.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/EnumerableMap.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/SafeCast.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/SafeERC20.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/helpers/InputHelpers.sol";
    import "@balancer-labs/v2-solidity-utils/contracts/math/Math.sol";
    import "./PoolBalances.sol";
    import "@balancer-labs/v2-vault/contracts/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; 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; 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; 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: 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/solidity-utils/misc/IWETH.sol";
    import "@balancer-labs/v2-interfaces/contracts/vault/IAuthorizer.sol";
    import "@balancer-labs/v2-vault/contracts/VaultAuthorization.sol";
    import "@balancer-labs/v2-vault/contracts/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();
        }
    }
    

    File 2 of 2: Authorizer
    // 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 "../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 "./EnumerableSet.sol";
    /**
     * @dev Contract module that allows children to implement role-based access
     * control mechanisms.
     *
     * 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 {
        using EnumerableSet for EnumerableSet.AddressSet;
        struct RoleData {
            EnumerableSet.AddressSet members;
            bytes32 adminRole;
        }
        mapping(bytes32 => RoleData) private _roles;
        bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
        /**
         * @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 {_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) public view virtual returns (bool) {
            return _roles[role].members.contains(account);
        }
        /**
         * @dev Returns the number of accounts that have `role`. Can be used
         * together with {getRoleMember} to enumerate all bearers of a role.
         */
        function getRoleMemberCount(bytes32 role) public view returns (uint256) {
            return _roles[role].members.length();
        }
        /**
         * @dev Returns one of the accounts that have `role`. `index` must be a
         * value between 0 and {getRoleMemberCount}, non-inclusive.
         *
         * Role bearers are not sorted in any particular way, and their ordering may
         * change at any point.
         *
         * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
         * you perform all queries on the same block. See the following
         * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
         * for more information.
         */
        function getRoleMember(bytes32 role, uint256 index) public view returns (address) {
            return _roles[role].members.at(index);
        }
        /**
         * @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 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 {
            _require(hasRole(_roles[role].adminRole, msg.sender), Errors.GRANT_SENDER_NOT_ADMIN);
            _grantRole(role, account);
        }
        /**
         * @dev Revokes `role` from `account`.
         *
         * If `account` had already been granted `role`, emits a {RoleRevoked} event.
         *
         * Requirements:
         *
         * - the caller must have ``role``'s admin role.
         */
        function revokeRole(bytes32 role, address account) public virtual {
            _require(hasRole(_roles[role].adminRole, msg.sender), Errors.REVOKE_SENDER_NOT_ADMIN);
            _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 {
            _require(account == msg.sender, Errors.RENOUNCE_SENDER_NOT_ALLOWED);
            _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 {
            emit RoleAdminChanged(role, _roles[role].adminRole, adminRole);
            _roles[role].adminRole = adminRole;
        }
        function _grantRole(bytes32 role, address account) private {
            if (_roles[role].members.add(account)) {
                emit RoleGranted(role, account, msg.sender);
            }
        }
        function _revokeRole(bytes32 role, address account) private {
            if (_roles[role].members.remove(account)) {
                emit RoleRevoked(role, account, msg.sender);
            }
        }
    }
    // 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;
    /**
     * @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;
    import "./interfaces/IAuthorizer.sol";
    import "../lib/openzeppelin/AccessControl.sol";
    import "../lib/helpers/InputHelpers.sol";
    /**
     * @dev Basic Authorizer implementation, based on OpenZeppelin's Access Control.
     *
     * Users are allowed to perform actions if they have the role with the same identifier. In this sense, roles are not
     * being truly used as such, since they each map to a single action identifier.
     *
     * This temporary implementation is expected to be replaced soon after launch by a more sophisticated one, able to
     * manage permissions across multiple contracts and to natively handle timelocks.
     */
    contract Authorizer is AccessControl, IAuthorizer {
        constructor(address admin) {
            _setupRole(DEFAULT_ADMIN_ROLE, admin);
        }
        function canPerform(
            bytes32 actionId,
            address account,
            address
        ) public view override returns (bool) {
            // This Authorizer ignores the 'where' field completely.
            return AccessControl.hasRole(actionId, account);
        }
        /**
         * @dev Grants multiple roles to a single account.
         */
        function grantRoles(bytes32[] memory roles, address account) external {
            for (uint256 i = 0; i < roles.length; i++) {
                grantRole(roles[i], account);
            }
        }
        /**
         * @dev Grants roles to a list of accounts.
         */
        function grantRolesToMany(bytes32[] memory roles, address[] memory accounts) external {
            InputHelpers.ensureInputLengthMatch(roles.length, accounts.length);
            for (uint256 i = 0; i < roles.length; i++) {
                grantRole(roles[i], accounts[i]);
            }
        }
        /**
         * @dev Revokes multiple roles from a single account.
         */
        function revokeRoles(bytes32[] memory roles, address account) external {
            for (uint256 i = 0; i < roles.length; i++) {
                revokeRole(roles[i], account);
            }
        }
        /**
         * @dev Revokes roles from a list of accounts.
         */
        function revokeRolesFromMany(bytes32[] memory roles, address[] memory accounts) external {
            InputHelpers.ensureInputLengthMatch(roles.length, accounts.length);
            for (uint256 i = 0; i < roles.length; i++) {
                revokeRole(roles[i], accounts[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;
    /**
     * @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);
    }