// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
import "./BalancerErrors.sol";
import "./IAuthentication.sol";
/**
* @dev Building block for performing access control on external functions.
*
* This contract is used via the `authenticate` modifier (or the `_authenticateCaller` function), which can be applied
* to external functions to only make them callable by authorized accounts.
*
* Derived contracts must implement the `_canPerform` function, which holds the actual access control logic.
*/
abstract contract Authentication is IAuthentication {
bytes32 private immutable _actionIdDisambiguator;
/**
* @dev The main purpose of the `actionIdDisambiguator` is to prevent accidental function selector collisions in
* multi contract systems.
*
* There are two main uses for it:
* - if the contract is a singleton, any unique identifier can be used to make the associated action identifiers
* unique. The contract's own address is a good option.
* - if the contract belongs to a family that shares action identifiers for the same functions, an identifier
* shared by the entire family (and no other contract) should be used instead.
*/
constructor(bytes32 actionIdDisambiguator) {
_actionIdDisambiguator = actionIdDisambiguator;
}
/**
* @dev Reverts unless the caller is allowed to call this function. Should only be applied to external functions.
*/
modifier authenticate() {
_authenticateCaller();
_;
}
/**
* @dev Reverts unless the caller is allowed to call the entry point function.
*/
function _authenticateCaller() internal view {
bytes32 actionId = getActionId(msg.sig);
_require(_canPerform(actionId, msg.sender), Errors.SENDER_NOT_ALLOWED);
}
function getActionId(bytes4 selector) public view override returns (bytes32) {
// Each external function is dynamically assigned an action identifier as the hash of the disambiguator and the
// function selector. Disambiguation is necessary to avoid potential collisions in the function selectors of
// multiple contracts.
return keccak256(abi.encodePacked(_actionIdDisambiguator, selector));
}
function _canPerform(bytes32 actionId, address user) internal view virtual returns (bool);
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
// 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;
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;
// 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 "../lib/math/Math.sol";
import "../lib/openzeppelin/IERC20.sol";
import "../lib/openzeppelin/IERC20Permit.sol";
import "../lib/openzeppelin/EIP712.sol";
/**
* @title Highly opinionated token implementation
* @author Balancer Labs
* @dev
* - Includes functions to increase and decrease allowance as a workaround
* for the well-known issue with `approve`:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
* - Allows for 'infinite allowance', where an allowance of 0xff..ff is not
* decreased by calls to transferFrom
* - Lets a token holder use `transferFrom` to send their own tokens,
* without first setting allowance
* - Emits 'Approval' events whenever allowance is changed by `transferFrom`
*/
contract BalancerPoolToken is IERC20, IERC20Permit, EIP712 {
using Math for uint256;
// State variables
uint8 private constant _DECIMALS = 18;
mapping(address => uint256) private _balance;
mapping(address => mapping(address => uint256)) private _allowance;
uint256 private _totalSupply;
string private _name;
string private _symbol;
mapping(address => uint256) private _nonces;
// solhint-disable-next-line var-name-mixedcase
bytes32 private immutable _PERMIT_TYPE_HASH = keccak256(
"Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)"
);
// Function declarations
constructor(string memory tokenName, string memory tokenSymbol) EIP712(tokenName, "1") {
_name = tokenName;
_symbol = tokenSymbol;
}
// External functions
function allowance(address owner, address spender) external view override returns (uint256) {
return _allowance[owner][spender];
}
function balanceOf(address account) external view override returns (uint256) {
return _balance[account];
}
function approve(address spender, uint256 amount) external override returns (bool) {
_setAllowance(msg.sender, spender, amount);
return true;
}
function increaseApproval(address spender, uint256 amount) external returns (bool) {
_setAllowance(msg.sender, spender, _allowance[msg.sender][spender].add(amount));
return true;
}
function decreaseApproval(address spender, uint256 amount) external returns (bool) {
uint256 currentAllowance = _allowance[msg.sender][spender];
if (amount >= currentAllowance) {
_setAllowance(msg.sender, spender, 0);
} else {
_setAllowance(msg.sender, spender, currentAllowance.sub(amount));
}
return true;
}
function transfer(address recipient, uint256 amount) external override returns (bool) {
_move(msg.sender, recipient, amount);
return true;
}
function transferFrom(
address sender,
address recipient,
uint256 amount
) external override returns (bool) {
uint256 currentAllowance = _allowance[sender][msg.sender];
_require(msg.sender == sender || currentAllowance >= amount, Errors.INSUFFICIENT_ALLOWANCE);
_move(sender, recipient, amount);
if (msg.sender != sender && currentAllowance != uint256(-1)) {
// Because of the previous require, we know that if msg.sender != sender then currentAllowance >= amount
_setAllowance(sender, msg.sender, currentAllowance - amount);
}
return true;
}
function permit(
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) public virtual override {
// solhint-disable-next-line not-rely-on-time
_require(block.timestamp <= deadline, Errors.EXPIRED_PERMIT);
uint256 nonce = _nonces[owner];
bytes32 structHash = keccak256(abi.encode(_PERMIT_TYPE_HASH, owner, spender, value, nonce, deadline));
bytes32 hash = _hashTypedDataV4(structHash);
address signer = ecrecover(hash, v, r, s);
_require((signer != address(0)) && (signer == owner), Errors.INVALID_SIGNATURE);
_nonces[owner] = nonce + 1;
_setAllowance(owner, spender, value);
}
// Public functions
function name() public view returns (string memory) {
return _name;
}
function symbol() public view returns (string memory) {
return _symbol;
}
function decimals() public pure returns (uint8) {
return _DECIMALS;
}
function totalSupply() public view override returns (uint256) {
return _totalSupply;
}
function nonces(address owner) external view override returns (uint256) {
return _nonces[owner];
}
// solhint-disable-next-line func-name-mixedcase
function DOMAIN_SEPARATOR() external view override returns (bytes32) {
return _domainSeparatorV4();
}
// Internal functions
function _mintPoolTokens(address recipient, uint256 amount) internal {
_balance[recipient] = _balance[recipient].add(amount);
_totalSupply = _totalSupply.add(amount);
emit Transfer(address(0), recipient, amount);
}
function _burnPoolTokens(address sender, uint256 amount) internal {
uint256 currentBalance = _balance[sender];
_require(currentBalance >= amount, Errors.INSUFFICIENT_BALANCE);
_balance[sender] = currentBalance - amount;
_totalSupply = _totalSupply.sub(amount);
emit Transfer(sender, address(0), amount);
}
function _move(
address sender,
address recipient,
uint256 amount
) internal {
uint256 currentBalance = _balance[sender];
_require(currentBalance >= amount, Errors.INSUFFICIENT_BALANCE);
// Prohibit transfers to the zero address to avoid confusion with the
// Transfer event emitted by `_burnPoolTokens`
_require(recipient != address(0), Errors.ERC20_TRANSFER_TO_ZERO_ADDRESS);
_balance[sender] = currentBalance - amount;
_balance[recipient] = _balance[recipient].add(amount);
emit Transfer(sender, recipient, amount);
}
// Private functions
function _setAllowance(
address owner,
address spender,
uint256 amount
) private {
_allowance[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
pragma experimental ABIEncoderV2;
import "./BasePool.sol";
import "../vault/interfaces/IMinimalSwapInfoPool.sol";
/**
* @dev Extension of `BasePool`, adding a handler for `IMinimalSwapInfoPool.onSwap`.
*
* Derived contracts must implement `_onSwapGivenIn` and `_onSwapGivenOut` along with `BasePool`'s virtual functions.
*/
abstract contract BaseMinimalSwapInfoPool is IMinimalSwapInfoPool, BasePool {
constructor(
IVault vault,
string memory name,
string memory symbol,
IERC20[] memory tokens,
uint256 swapFeePercentage,
uint256 pauseWindowDuration,
uint256 bufferPeriodDuration,
address owner
)
BasePool(
vault,
tokens.length == 2 ? IVault.PoolSpecialization.TWO_TOKEN : IVault.PoolSpecialization.MINIMAL_SWAP_INFO,
name,
symbol,
tokens,
swapFeePercentage,
pauseWindowDuration,
bufferPeriodDuration,
owner
)
{
// solhint-disable-previous-line no-empty-blocks
}
// Swap Hooks
function onSwap(
SwapRequest memory request,
uint256 balanceTokenIn,
uint256 balanceTokenOut
) external view virtual override returns (uint256) {
uint256 scalingFactorTokenIn = _scalingFactor(request.tokenIn);
uint256 scalingFactorTokenOut = _scalingFactor(request.tokenOut);
if (request.kind == IVault.SwapKind.GIVEN_IN) {
// Fees are subtracted before scaling, to reduce the complexity of the rounding direction analysis.
request.amount = _subtractSwapFeeAmount(request.amount);
// All token amounts are upscaled.
balanceTokenIn = _upscale(balanceTokenIn, scalingFactorTokenIn);
balanceTokenOut = _upscale(balanceTokenOut, scalingFactorTokenOut);
request.amount = _upscale(request.amount, scalingFactorTokenIn);
uint256 amountOut = _onSwapGivenIn(request, balanceTokenIn, balanceTokenOut);
// amountOut tokens are exiting the Pool, so we round down.
return _downscaleDown(amountOut, scalingFactorTokenOut);
} else {
// All token amounts are upscaled.
balanceTokenIn = _upscale(balanceTokenIn, scalingFactorTokenIn);
balanceTokenOut = _upscale(balanceTokenOut, scalingFactorTokenOut);
request.amount = _upscale(request.amount, scalingFactorTokenOut);
uint256 amountIn = _onSwapGivenOut(request, balanceTokenIn, balanceTokenOut);
// amountIn tokens are entering the Pool, so we round up.
amountIn = _downscaleUp(amountIn, scalingFactorTokenIn);
// Fees are added after scaling happens, to reduce the complexity of the rounding direction analysis.
return _addSwapFeeAmount(amountIn);
}
}
/*
* @dev Called when a swap with the Pool occurs, where the amount of tokens entering the Pool is known.
*
* Returns the amount of tokens that will be taken from the Pool in return.
*
* All amounts inside `swapRequest`, `balanceTokenIn` and `balanceTokenOut` are upscaled. The swap fee has already
* been deducted from `swapRequest.amount`.
*
* The return value is also considered upscaled, and will be downscaled (rounding down) before returning it to the
* Vault.
*/
function _onSwapGivenIn(
SwapRequest memory swapRequest,
uint256 balanceTokenIn,
uint256 balanceTokenOut
) internal view virtual returns (uint256);
/*
* @dev Called when a swap with the Pool occurs, where the amount of tokens exiting the Pool is known.
*
* Returns the amount of tokens that will be granted to the Pool in return.
*
* All amounts inside `swapRequest`, `balanceTokenIn` and `balanceTokenOut` are upscaled.
*
* The return value is also considered upscaled, and will be downscaled (rounding up) before applying the swap fee
* and returning it to the Vault.
*/
function _onSwapGivenOut(
SwapRequest memory swapRequest,
uint256 balanceTokenIn,
uint256 balanceTokenOut
) internal view 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;
pragma experimental ABIEncoderV2;
import "../lib/math/FixedPoint.sol";
import "../lib/helpers/InputHelpers.sol";
import "../lib/helpers/TemporarilyPausable.sol";
import "../lib/openzeppelin/ERC20.sol";
import "./BalancerPoolToken.sol";
import "./BasePoolAuthorization.sol";
import "../vault/interfaces/IVault.sol";
import "../vault/interfaces/IBasePool.sol";
// This contract relies on tons of immutable state variables to perform efficient lookup, without resorting to storage
// reads. Because immutable arrays are not supported, we instead declare a fixed set of state variables plus a total
// count, resulting in a large number of state variables.
// solhint-disable max-states-count
/**
* @dev Reference implementation for the base layer of a Pool contract that manages a single Pool with an immutable set
* of registered tokens, no Asset Managers, an admin-controlled swap fee percentage, and an emergency pause mechanism.
*
* Note that neither swap fees nor the pause mechanism are used by this contract. They are passed through so that
* derived contracts can use them via the `_addSwapFeeAmount` and `_subtractSwapFeeAmount` functions, and the
* `whenNotPaused` modifier.
*
* No admin permissions are checked here: instead, this contract delegates that to the Vault's own Authorizer.
*
* Because this contract doesn't implement the swap hooks, derived contracts should generally inherit from
* BaseGeneralPool or BaseMinimalSwapInfoPool. Otherwise, subclasses must inherit from the corresponding interfaces
* and implement the swap callbacks themselves.
*/
abstract contract BasePool is IBasePool, BasePoolAuthorization, BalancerPoolToken, TemporarilyPausable {
using FixedPoint for uint256;
uint256 private constant _MIN_TOKENS = 2;
uint256 private constant _MAX_TOKENS = 8;
// 1e18 corresponds to 1.0, or a 100% fee
uint256 private constant _MIN_SWAP_FEE_PERCENTAGE = 1e12; // 0.0001%
uint256 private constant _MAX_SWAP_FEE_PERCENTAGE = 1e17; // 10%
uint256 private constant _MINIMUM_BPT = 1e6;
uint256 internal _swapFeePercentage;
IVault private immutable _vault;
bytes32 private immutable _poolId;
uint256 private immutable _totalTokens;
IERC20 internal immutable _token0;
IERC20 internal immutable _token1;
IERC20 internal immutable _token2;
IERC20 internal immutable _token3;
IERC20 internal immutable _token4;
IERC20 internal immutable _token5;
IERC20 internal immutable _token6;
IERC20 internal immutable _token7;
// All token balances are normalized to behave as if the token had 18 decimals. We assume a token's decimals will
// not change throughout its lifetime, and store the corresponding scaling factor for each at construction time.
// These factors are always greater than or equal to one: tokens with more than 18 decimals are not supported.
uint256 internal immutable _scalingFactor0;
uint256 internal immutable _scalingFactor1;
uint256 internal immutable _scalingFactor2;
uint256 internal immutable _scalingFactor3;
uint256 internal immutable _scalingFactor4;
uint256 internal immutable _scalingFactor5;
uint256 internal immutable _scalingFactor6;
uint256 internal immutable _scalingFactor7;
event SwapFeePercentageChanged(uint256 swapFeePercentage);
constructor(
IVault vault,
IVault.PoolSpecialization specialization,
string memory name,
string memory symbol,
IERC20[] memory tokens,
uint256 swapFeePercentage,
uint256 pauseWindowDuration,
uint256 bufferPeriodDuration,
address owner
)
// Base Pools are expected to be deployed using factories. By using the factory address as the action
// disambiguator, we make all Pools deployed by the same factory share action identifiers. This allows for
// simpler management of permissions (such as being able to manage granting the 'set fee percentage' action in
// any Pool created by the same factory), while still making action identifiers unique among different factories
// if the selectors match, preventing accidental errors.
Authentication(bytes32(uint256(msg.sender)))
BalancerPoolToken(name, symbol)
BasePoolAuthorization(owner)
TemporarilyPausable(pauseWindowDuration, bufferPeriodDuration)
{
_require(tokens.length >= _MIN_TOKENS, Errors.MIN_TOKENS);
_require(tokens.length <= _MAX_TOKENS, Errors.MAX_TOKENS);
// The Vault only requires the token list to be ordered for the Two Token Pools specialization. However,
// to make the developer experience consistent, we are requiring this condition for all the native pools.
// Also, since these Pools will register tokens only once, we can ensure the Pool tokens will follow the same
// order. We rely on this property to make Pools simpler to write, as it lets us assume that the
// order of token-specific parameters (such as token weights) will not change.
InputHelpers.ensureArrayIsSorted(tokens);
_setSwapFeePercentage(swapFeePercentage);
bytes32 poolId = vault.registerPool(specialization);
// Pass in zero addresses for Asset Managers
vault.registerTokens(poolId, tokens, new address[](tokens.length));
// Set immutable state variables - these cannot be read from during construction
_vault = vault;
_poolId = poolId;
_totalTokens = tokens.length;
// Immutable variables cannot be initialized inside an if statement, so we must do conditional assignments
_token0 = tokens.length > 0 ? tokens[0] : IERC20(0);
_token1 = tokens.length > 1 ? tokens[1] : IERC20(0);
_token2 = tokens.length > 2 ? tokens[2] : IERC20(0);
_token3 = tokens.length > 3 ? tokens[3] : IERC20(0);
_token4 = tokens.length > 4 ? tokens[4] : IERC20(0);
_token5 = tokens.length > 5 ? tokens[5] : IERC20(0);
_token6 = tokens.length > 6 ? tokens[6] : IERC20(0);
_token7 = tokens.length > 7 ? tokens[7] : IERC20(0);
_scalingFactor0 = tokens.length > 0 ? _computeScalingFactor(tokens[0]) : 0;
_scalingFactor1 = tokens.length > 1 ? _computeScalingFactor(tokens[1]) : 0;
_scalingFactor2 = tokens.length > 2 ? _computeScalingFactor(tokens[2]) : 0;
_scalingFactor3 = tokens.length > 3 ? _computeScalingFactor(tokens[3]) : 0;
_scalingFactor4 = tokens.length > 4 ? _computeScalingFactor(tokens[4]) : 0;
_scalingFactor5 = tokens.length > 5 ? _computeScalingFactor(tokens[5]) : 0;
_scalingFactor6 = tokens.length > 6 ? _computeScalingFactor(tokens[6]) : 0;
_scalingFactor7 = tokens.length > 7 ? _computeScalingFactor(tokens[7]) : 0;
}
// Getters / Setters
function getVault() public view returns (IVault) {
return _vault;
}
function getPoolId() public view returns (bytes32) {
return _poolId;
}
function _getTotalTokens() internal view returns (uint256) {
return _totalTokens;
}
function getSwapFeePercentage() external view returns (uint256) {
return _swapFeePercentage;
}
// Caller must be approved by the Vault's Authorizer
function setSwapFeePercentage(uint256 swapFeePercentage) external virtual authenticate whenNotPaused {
_setSwapFeePercentage(swapFeePercentage);
}
function _setSwapFeePercentage(uint256 swapFeePercentage) private {
_require(swapFeePercentage >= _MIN_SWAP_FEE_PERCENTAGE, Errors.MIN_SWAP_FEE_PERCENTAGE);
_require(swapFeePercentage <= _MAX_SWAP_FEE_PERCENTAGE, Errors.MAX_SWAP_FEE_PERCENTAGE);
_swapFeePercentage = swapFeePercentage;
emit SwapFeePercentageChanged(swapFeePercentage);
}
// Caller must be approved by the Vault's Authorizer
function setPaused(bool paused) external authenticate {
_setPaused(paused);
}
// Join / Exit Hooks
modifier onlyVault(bytes32 poolId) {
_require(msg.sender == address(getVault()), Errors.CALLER_NOT_VAULT);
_require(poolId == getPoolId(), Errors.INVALID_POOL_ID);
_;
}
function onJoinPool(
bytes32 poolId,
address sender,
address recipient,
uint256[] memory balances,
uint256 lastChangeBlock,
uint256 protocolSwapFeePercentage,
bytes memory userData
) external virtual override onlyVault(poolId) returns (uint256[] memory, uint256[] memory) {
uint256[] memory scalingFactors = _scalingFactors();
if (totalSupply() == 0) {
(uint256 bptAmountOut, uint256[] memory amountsIn) = _onInitializePool(poolId, sender, recipient, userData);
// On initialization, we lock _MINIMUM_BPT by minting it for the zero address. This BPT acts as a minimum
// as it will never be burned, which reduces potential issues with rounding, and also prevents the Pool from
// ever being fully drained.
_require(bptAmountOut >= _MINIMUM_BPT, Errors.MINIMUM_BPT);
_mintPoolTokens(address(0), _MINIMUM_BPT);
_mintPoolTokens(recipient, bptAmountOut - _MINIMUM_BPT);
// amountsIn are amounts entering the Pool, so we round up.
_downscaleUpArray(amountsIn, scalingFactors);
return (amountsIn, new uint256[](_getTotalTokens()));
} else {
_upscaleArray(balances, scalingFactors);
(uint256 bptAmountOut, uint256[] memory amountsIn, uint256[] memory dueProtocolFeeAmounts) = _onJoinPool(
poolId,
sender,
recipient,
balances,
lastChangeBlock,
protocolSwapFeePercentage,
userData
);
// Note we no longer use `balances` after calling `_onJoinPool`, which may mutate it.
_mintPoolTokens(recipient, bptAmountOut);
// amountsIn are amounts entering the Pool, so we round up.
_downscaleUpArray(amountsIn, scalingFactors);
// dueProtocolFeeAmounts are amounts exiting the Pool, so we round down.
_downscaleDownArray(dueProtocolFeeAmounts, scalingFactors);
return (amountsIn, dueProtocolFeeAmounts);
}
}
function onExitPool(
bytes32 poolId,
address sender,
address recipient,
uint256[] memory balances,
uint256 lastChangeBlock,
uint256 protocolSwapFeePercentage,
bytes memory userData
) external virtual override onlyVault(poolId) returns (uint256[] memory, uint256[] memory) {
uint256[] memory scalingFactors = _scalingFactors();
_upscaleArray(balances, scalingFactors);
(uint256 bptAmountIn, uint256[] memory amountsOut, uint256[] memory dueProtocolFeeAmounts) = _onExitPool(
poolId,
sender,
recipient,
balances,
lastChangeBlock,
protocolSwapFeePercentage,
userData
);
// Note we no longer use `balances` after calling `_onExitPool`, which may mutate it.
_burnPoolTokens(sender, bptAmountIn);
// Both amountsOut and dueProtocolFeeAmounts are amounts exiting the Pool, so we round down.
_downscaleDownArray(amountsOut, scalingFactors);
_downscaleDownArray(dueProtocolFeeAmounts, scalingFactors);
return (amountsOut, dueProtocolFeeAmounts);
}
// Query functions
/**
* @dev Returns the amount of BPT that would be granted to `recipient` if the `onJoinPool` hook were called by the
* Vault with the same arguments, along with the number of tokens `sender` would have to supply.
*
* This function is not meant to be called directly, but rather from a helper contract that fetches current Vault
* data, such as the protocol swap fee percentage and Pool balances.
*
* Like `IVault.queryBatchSwap`, this function is not view due to internal implementation details: the caller must
* explicitly use eth_call instead of eth_sendTransaction.
*/
function queryJoin(
bytes32 poolId,
address sender,
address recipient,
uint256[] memory balances,
uint256 lastChangeBlock,
uint256 protocolSwapFeePercentage,
bytes memory userData
) external returns (uint256 bptOut, uint256[] memory amountsIn) {
InputHelpers.ensureInputLengthMatch(balances.length, _getTotalTokens());
_queryAction(
poolId,
sender,
recipient,
balances,
lastChangeBlock,
protocolSwapFeePercentage,
userData,
_onJoinPool,
_downscaleUpArray
);
// The `return` opcode is executed directly inside `_queryAction`, so execution never reaches this statement,
// and we don't need to return anything here - it just silences compiler warnings.
return (bptOut, amountsIn);
}
/**
* @dev Returns the amount of BPT that would be burned from `sender` if the `onExitPool` hook were called by the
* Vault with the same arguments, along with the number of tokens `recipient` would receive.
*
* This function is not meant to be called directly, but rather from a helper contract that fetches current Vault
* data, such as the protocol swap fee percentage and Pool balances.
*
* Like `IVault.queryBatchSwap`, this function is not view due to internal implementation details: the caller must
* explicitly use eth_call instead of eth_sendTransaction.
*/
function queryExit(
bytes32 poolId,
address sender,
address recipient,
uint256[] memory balances,
uint256 lastChangeBlock,
uint256 protocolSwapFeePercentage,
bytes memory userData
) external returns (uint256 bptIn, uint256[] memory amountsOut) {
InputHelpers.ensureInputLengthMatch(balances.length, _getTotalTokens());
_queryAction(
poolId,
sender,
recipient,
balances,
lastChangeBlock,
protocolSwapFeePercentage,
userData,
_onExitPool,
_downscaleDownArray
);
// The `return` opcode is executed directly inside `_queryAction`, so execution never reaches this statement,
// and we don't need to return anything here - it just silences compiler warnings.
return (bptIn, amountsOut);
}
// Internal hooks to be overridden by derived contracts - all token amounts (except BPT) in these interfaces are
// upscaled.
/**
* @dev Called when the Pool is joined for the first time; that is, when the BPT total supply is zero.
*
* Returns the amount of BPT to mint, and the token amounts the Pool will receive in return.
*
* Minted BPT will be sent to `recipient`, except for _MINIMUM_BPT, which will be deducted from this amount and sent
* to the zero address instead. This will cause that BPT to remain forever locked there, preventing total BTP from
* ever dropping below that value, and ensuring `_onInitializePool` can only be called once in the entire Pool's
* lifetime.
*
* The tokens granted to the Pool will be transferred from `sender`. These amounts are considered upscaled and will
* be downscaled (rounding up) before being returned to the Vault.
*/
function _onInitializePool(
bytes32 poolId,
address sender,
address recipient,
bytes memory userData
) internal virtual returns (uint256 bptAmountOut, uint256[] memory amountsIn);
/**
* @dev Called whenever the Pool is joined after the first initialization join (see `_onInitializePool`).
*
* Returns the amount of BPT to mint, the token amounts that the Pool will receive in return, and the number of
* tokens to pay in protocol swap fees.
*
* Implementations of this function might choose to mutate the `balances` array to save gas (e.g. when
* performing intermediate calculations, such as subtraction of due protocol fees). This can be done safely.
*
* Minted BPT will be sent to `recipient`.
*
* The tokens granted to the Pool will be transferred from `sender`. These amounts are considered upscaled and will
* be downscaled (rounding up) before being returned to the Vault.
*
* Due protocol swap fees will be taken from the Pool's balance in the Vault (see `IBasePool.onJoinPool`). These
* amounts are considered upscaled and will be downscaled (rounding down) before being returned to the Vault.
*/
function _onJoinPool(
bytes32 poolId,
address sender,
address recipient,
uint256[] memory balances,
uint256 lastChangeBlock,
uint256 protocolSwapFeePercentage,
bytes memory userData
)
internal
virtual
returns (
uint256 bptAmountOut,
uint256[] memory amountsIn,
uint256[] memory dueProtocolFeeAmounts
);
/**
* @dev Called whenever the Pool is exited.
*
* Returns the amount of BPT to burn, the token amounts for each Pool token that the Pool will grant in return, and
* the number of tokens to pay in protocol swap fees.
*
* Implementations of this function might choose to mutate the `balances` array to save gas (e.g. when
* performing intermediate calculations, such as subtraction of due protocol fees). This can be done safely.
*
* BPT will be burnt from `sender`.
*
* The Pool will grant tokens to `recipient`. These amounts are considered upscaled and will be downscaled
* (rounding down) before being returned to the Vault.
*
* Due protocol swap fees will be taken from the Pool's balance in the Vault (see `IBasePool.onExitPool`). These
* amounts are considered upscaled and will be downscaled (rounding down) before being returned to the Vault.
*/
function _onExitPool(
bytes32 poolId,
address sender,
address recipient,
uint256[] memory balances,
uint256 lastChangeBlock,
uint256 protocolSwapFeePercentage,
bytes memory userData
)
internal
virtual
returns (
uint256 bptAmountIn,
uint256[] memory amountsOut,
uint256[] memory dueProtocolFeeAmounts
);
// Internal functions
/**
* @dev Adds swap fee amount to `amount`, returning a higher value.
*/
function _addSwapFeeAmount(uint256 amount) internal view returns (uint256) {
// This returns amount + fee amount, so we round up (favoring a higher fee amount).
return amount.divUp(_swapFeePercentage.complement());
}
/**
* @dev Subtracts swap fee amount from `amount`, returning a lower value.
*/
function _subtractSwapFeeAmount(uint256 amount) internal view returns (uint256) {
// This returns amount - fee amount, so we round up (favoring a higher fee amount).
uint256 feeAmount = amount.mulUp(_swapFeePercentage);
return amount.sub(feeAmount);
}
// Scaling
/**
* @dev Returns a scaling factor that, when multiplied to a token amount for `token`, normalizes its balance as if
* it had 18 decimals.
*/
function _computeScalingFactor(IERC20 token) private view returns (uint256) {
// Tokens that don't implement the `decimals` method are not supported.
uint256 tokenDecimals = ERC20(address(token)).decimals();
// Tokens with more than 18 decimals are not supported.
uint256 decimalsDifference = Math.sub(18, tokenDecimals);
return 10**decimalsDifference;
}
/**
* @dev Returns the scaling factor for one of the Pool's tokens. Reverts if `token` is not a token registered by the
* Pool.
*/
function _scalingFactor(IERC20 token) internal view returns (uint256) {
// prettier-ignore
if (token == _token0) { return _scalingFactor0; }
else if (token == _token1) { return _scalingFactor1; }
else if (token == _token2) { return _scalingFactor2; }
else if (token == _token3) { return _scalingFactor3; }
else if (token == _token4) { return _scalingFactor4; }
else if (token == _token5) { return _scalingFactor5; }
else if (token == _token6) { return _scalingFactor6; }
else if (token == _token7) { return _scalingFactor7; }
else {
_revert(Errors.INVALID_TOKEN);
}
}
/**
* @dev Returns all the scaling factors in the same order as the registered tokens. The Vault will always
* pass balances in this order when calling any of the Pool hooks
*/
function _scalingFactors() internal view returns (uint256[] memory) {
uint256 totalTokens = _getTotalTokens();
uint256[] memory scalingFactors = new uint256[](totalTokens);
// prettier-ignore
{
if (totalTokens > 0) { scalingFactors[0] = _scalingFactor0; } else { return scalingFactors; }
if (totalTokens > 1) { scalingFactors[1] = _scalingFactor1; } else { return scalingFactors; }
if (totalTokens > 2) { scalingFactors[2] = _scalingFactor2; } else { return scalingFactors; }
if (totalTokens > 3) { scalingFactors[3] = _scalingFactor3; } else { return scalingFactors; }
if (totalTokens > 4) { scalingFactors[4] = _scalingFactor4; } else { return scalingFactors; }
if (totalTokens > 5) { scalingFactors[5] = _scalingFactor5; } else { return scalingFactors; }
if (totalTokens > 6) { scalingFactors[6] = _scalingFactor6; } else { return scalingFactors; }
if (totalTokens > 7) { scalingFactors[7] = _scalingFactor7; } else { return scalingFactors; }
}
return scalingFactors;
}
/**
* @dev Applies `scalingFactor` to `amount`, resulting in a larger or equal value depending on whether it needed
* scaling or not.
*/
function _upscale(uint256 amount, uint256 scalingFactor) internal pure returns (uint256) {
return Math.mul(amount, scalingFactor);
}
/**
* @dev Same as `_upscale`, but for an entire array. This function does not return anything, but instead *mutates*
* the `amounts` array.
*/
function _upscaleArray(uint256[] memory amounts, uint256[] memory scalingFactors) internal view {
for (uint256 i = 0; i < _getTotalTokens(); ++i) {
amounts[i] = Math.mul(amounts[i], scalingFactors[i]);
}
}
/**
* @dev Reverses the `scalingFactor` applied to `amount`, resulting in a smaller or equal value depending on
* whether it needed scaling or not. The result is rounded down.
*/
function _downscaleDown(uint256 amount, uint256 scalingFactor) internal pure returns (uint256) {
return Math.divDown(amount, scalingFactor);
}
/**
* @dev Same as `_downscaleDown`, but for an entire array. This function does not return anything, but instead
* *mutates* the `amounts` array.
*/
function _downscaleDownArray(uint256[] memory amounts, uint256[] memory scalingFactors) internal view {
for (uint256 i = 0; i < _getTotalTokens(); ++i) {
amounts[i] = Math.divDown(amounts[i], scalingFactors[i]);
}
}
/**
* @dev Reverses the `scalingFactor` applied to `amount`, resulting in a smaller or equal value depending on
* whether it needed scaling or not. The result is rounded up.
*/
function _downscaleUp(uint256 amount, uint256 scalingFactor) internal pure returns (uint256) {
return Math.divUp(amount, scalingFactor);
}
/**
* @dev Same as `_downscaleUp`, but for an entire array. This function does not return anything, but instead
* *mutates* the `amounts` array.
*/
function _downscaleUpArray(uint256[] memory amounts, uint256[] memory scalingFactors) internal view {
for (uint256 i = 0; i < _getTotalTokens(); ++i) {
amounts[i] = Math.divUp(amounts[i], scalingFactors[i]);
}
}
function _getAuthorizer() internal view override returns (IAuthorizer) {
// Access control management is delegated to the Vault's Authorizer. This lets Balancer Governance manage which
// accounts can call permissioned functions: for example, to perform emergency pauses.
// If the owner is delegated, then *all* permissioned functions, including `setSwapFeePercentage`, will be under
// Governance control.
return getVault().getAuthorizer();
}
function _queryAction(
bytes32 poolId,
address sender,
address recipient,
uint256[] memory balances,
uint256 lastChangeBlock,
uint256 protocolSwapFeePercentage,
bytes memory userData,
function(bytes32, address, address, uint256[] memory, uint256, uint256, bytes memory)
internal
returns (uint256, uint256[] memory, uint256[] memory) _action,
function(uint256[] memory, uint256[] memory) internal view _downscaleArray
) private {
// This uses the same technique used by the Vault in queryBatchSwap. Refer to that function for a detailed
// explanation.
if (msg.sender != address(this)) {
// We perform an external call to ourselves, forwarding the same calldata. In this call, the else clause of
// the preceding if statement will be executed instead.
// solhint-disable-next-line avoid-low-level-calls
(bool success, ) = address(this).call(msg.data);
// solhint-disable-next-line no-inline-assembly
assembly {
// This call should always revert to decode the bpt and token amounts from the revert reason
switch success
case 0 {
// Note we are manually writing the memory slot 0. We can safely overwrite whatever is
// stored there as we take full control of the execution and then immediately return.
// We copy the first 4 bytes to check if it matches with the expected signature, otherwise
// there was another revert reason and we should forward it.
returndatacopy(0, 0, 0x04)
let error := and(mload(0), 0xffffffff00000000000000000000000000000000000000000000000000000000)
// If the first 4 bytes don't match with the expected signature, we forward the revert reason.
if eq(eq(error, 0x43adbafb00000000000000000000000000000000000000000000000000000000), 0) {
returndatacopy(0, 0, returndatasize())
revert(0, returndatasize())
}
// The returndata contains the signature, followed by the raw memory representation of the
// `bptAmount` and `tokenAmounts` (array: length + data). We need to return an ABI-encoded
// representation of these.
// An ABI-encoded response will include one additional field to indicate the starting offset of
// the `tokenAmounts` array. The `bptAmount` will be laid out in the first word of the
// returndata.
//
// In returndata:
// [ signature ][ bptAmount ][ tokenAmounts length ][ tokenAmounts values ]
// [ 4 bytes ][ 32 bytes ][ 32 bytes ][ (32 * length) bytes ]
//
// We now need to return (ABI-encoded values):
// [ bptAmount ][ tokeAmounts offset ][ tokenAmounts length ][ tokenAmounts values ]
// [ 32 bytes ][ 32 bytes ][ 32 bytes ][ (32 * length) bytes ]
// We copy 32 bytes for the `bptAmount` from returndata into memory.
// Note that we skip the first 4 bytes for the error signature
returndatacopy(0, 0x04, 32)
// The offsets are 32-bytes long, so the array of `tokenAmounts` will start after
// the initial 64 bytes.
mstore(0x20, 64)
// We now copy the raw memory array for the `tokenAmounts` from returndata into memory.
// Since bpt amount and offset take up 64 bytes, we start copying at address 0x40. We also
// skip the first 36 bytes from returndata, which correspond to the signature plus bpt amount.
returndatacopy(0x40, 0x24, sub(returndatasize(), 36))
// We finally return the ABI-encoded uint256 and the array, which has a total length equal to
// the size of returndata, plus the 32 bytes of the offset but without the 4 bytes of the
// error signature.
return(0, add(returndatasize(), 28))
}
default {
// This call should always revert, but we fail nonetheless if that didn't happen
invalid()
}
}
} else {
uint256[] memory scalingFactors = _scalingFactors();
_upscaleArray(balances, scalingFactors);
(uint256 bptAmount, uint256[] memory tokenAmounts, ) = _action(
poolId,
sender,
recipient,
balances,
lastChangeBlock,
protocolSwapFeePercentage,
userData
);
_downscaleArray(tokenAmounts, scalingFactors);
// solhint-disable-next-line no-inline-assembly
assembly {
// We will return a raw representation of `bptAmount` and `tokenAmounts` in memory, which is composed of
// a 32-byte uint256, followed by a 32-byte for the array length, and finally the 32-byte uint256 values
// Because revert expects a size in bytes, we multiply the array length (stored at `tokenAmounts`) by 32
let size := mul(mload(tokenAmounts), 32)
// We store the `bptAmount` in the previous slot to the `tokenAmounts` array. We can make sure there
// will be at least one available slot due to how the memory scratch space works.
// We can safely overwrite whatever is stored in this slot as we will revert immediately after that.
let start := sub(tokenAmounts, 0x20)
mstore(start, bptAmount)
// We send one extra value for the error signature "QueryError(uint256,uint256[])" which is 0x43adbafb
// We use the previous slot to `bptAmount`.
mstore(sub(start, 0x20), 0x0000000000000000000000000000000000000000000000000000000043adbafb)
start := sub(start, 0x04)
// When copying from `tokenAmounts` into returndata, we copy the additional 68 bytes to also return
// the `bptAmount`, the array 's length, and the error signature.
revert(start, add(size, 68))
}
}
}
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
import "../lib/helpers/Authentication.sol";
import "../vault/interfaces/IAuthorizer.sol";
import "./BasePool.sol";
/**
* @dev Base authorization layer implementation for Pools.
*
* The owner account can call some of the permissioned functions - access control of the rest is delegated to the
* Authorizer. Note that this owner is immutable: more sophisticated permission schemes, such as multiple ownership,
* granular roles, etc., could be built on top of this by making the owner a smart contract.
*
* Access control of all other permissioned functions is delegated to an Authorizer. It is also possible to delegate
* control of *all* permissioned functions to the Authorizer by setting the owner address to `_DELEGATE_OWNER`.
*/
abstract contract BasePoolAuthorization is Authentication {
address private immutable _owner;
address private constant _DELEGATE_OWNER = 0xBA1BA1ba1BA1bA1bA1Ba1BA1ba1BA1bA1ba1ba1B;
constructor(address owner) {
_owner = owner;
}
function getOwner() public view returns (address) {
return _owner;
}
function getAuthorizer() external view returns (IAuthorizer) {
return _getAuthorizer();
}
function _canPerform(bytes32 actionId, address account) internal view override returns (bool) {
if ((getOwner() != _DELEGATE_OWNER) && _isOwnerOnlyAction(actionId)) {
// Only the owner can perform "owner only" actions, unless the owner is delegated.
return msg.sender == getOwner();
} else {
// Non-owner actions are always processed via the Authorizer, as "owner only" ones are when delegated.
return _getAuthorizer().canPerform(actionId, account, address(this));
}
}
function _isOwnerOnlyAction(bytes32 actionId) private view returns (bool) {
// This implementation hardcodes the setSwapFeePercentage action identifier.
return actionId == getActionId(BasePool.setSwapFeePercentage.selector);
}
function _getAuthorizer() internal view virtual returns (IAuthorizer);
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
library Buffer {
// The buffer is a circular storage structure with 1024 slots.
// solhint-disable-next-line private-vars-leading-underscore
uint256 internal constant SIZE = 1024;
/**
* @dev Returns the index of the element before the one pointed by `index`.
*/
function prev(uint256 index) internal pure returns (uint256) {
return sub(index, 1);
}
/**
* @dev Returns the index of the element after the one pointed by `index`.
*/
function next(uint256 index) internal pure returns (uint256) {
return add(index, 1);
}
/**
* @dev Returns the index of an element `offset` slots after the one pointed by `index`.
*/
function add(uint256 index, uint256 offset) internal pure returns (uint256) {
return (index + offset) % SIZE;
}
/**
* @dev Returns the index of an element `offset` slots before the one pointed by `index`.
*/
function sub(uint256 index, uint256 offset) internal pure returns (uint256) {
return (index + SIZE - offset) % SIZE;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
* @dev https://eips.ethereum.org/EIPS/eip-712[EIP 712] is a standard for hashing and signing of typed structured data.
*
* The encoding specified in the EIP is very generic, and such a generic implementation in Solidity is not feasible,
* thus this contract does not implement the encoding itself. Protocols need to implement the type-specific encoding
* they need in their contracts using a combination of `abi.encode` and `keccak256`.
*
* This contract implements the EIP 712 domain separator ({_domainSeparatorV4}) that is used as part of the encoding
* scheme, and the final step of the encoding to obtain the message digest that is then signed via ECDSA
* ({_hashTypedDataV4}).
*
* The implementation of the domain separator was designed to be as efficient as possible while still properly updating
* the chain id to protect against replay attacks on an eventual fork of the chain.
*
* NOTE: This contract implements the version of the encoding known as "v4", as implemented by the JSON RPC method
* https://docs.metamask.io/guide/signing-data.html[`eth_signTypedDataV4` in MetaMask].
*
* _Available since v3.4._
*/
abstract contract EIP712 {
/* solhint-disable var-name-mixedcase */
bytes32 private immutable _HASHED_NAME;
bytes32 private immutable _HASHED_VERSION;
bytes32 private immutable _TYPE_HASH;
/* solhint-enable var-name-mixedcase */
/**
* @dev Initializes the domain separator and parameter caches.
*
* The meaning of `name` and `version` is specified in
* https://eips.ethereum.org/EIPS/eip-712#definition-of-domainseparator[EIP 712]:
*
* - `name`: the user readable name of the signing domain, i.e. the name of the DApp or the protocol.
* - `version`: the current major version of the signing domain.
*
* NOTE: These parameters cannot be changed except through a xref:learn::upgrading-smart-contracts.adoc[smart
* contract upgrade].
*/
constructor(string memory name, string memory version) {
_HASHED_NAME = keccak256(bytes(name));
_HASHED_VERSION = keccak256(bytes(version));
_TYPE_HASH = keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)");
}
/**
* @dev Returns the domain separator for the current chain.
*/
function _domainSeparatorV4() internal view virtual returns (bytes32) {
return keccak256(abi.encode(_TYPE_HASH, _HASHED_NAME, _HASHED_VERSION, _getChainId(), address(this)));
}
/**
* @dev Given an already https://eips.ethereum.org/EIPS/eip-712#definition-of-hashstruct[hashed struct], this
* function returns the hash of the fully encoded EIP712 message for this domain.
*
* This hash can be used together with {ECDSA-recover} to obtain the signer of a message. For example:
*
* ```solidity
* bytes32 digest = _hashTypedDataV4(keccak256(abi.encode(
* keccak256("Mail(address to,string contents)"),
* mailTo,
* keccak256(bytes(mailContents))
* )));
* address signer = ECDSA.recover(digest, signature);
* ```
*/
function _hashTypedDataV4(bytes32 structHash) internal view virtual returns (bytes32) {
return keccak256(abi.encodePacked("\x19\x01", _domainSeparatorV4(), structHash));
}
function _getChainId() private view returns (uint256 chainId) {
// Silence state mutability warning without generating bytecode.
// See https://github.com/ethereum/solidity/issues/10090#issuecomment-741789128 and
// https://github.com/ethereum/solidity/issues/2691
this;
// solhint-disable-next-line no-inline-assembly
assembly {
chainId := chainid()
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "../helpers/BalancerErrors.sol";
import "./IERC20.sol";
import "./SafeMath.sol";
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20PresetMinterPauser}.
*
* TIP: For a detailed writeup see our guide
* https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* We have followed general OpenZeppelin guidelines: functions revert instead
* of returning `false` on failure. This behavior is nonetheless conventional
* and does not conflict with the expectations of ERC20 applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/
contract ERC20 is IERC20 {
using SafeMath for uint256;
mapping(address => uint256) private _balances;
mapping(address => mapping(address => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
uint8 private _decimals;
/**
* @dev Sets the values for {name} and {symbol}, initializes {decimals} with
* a default value of 18.
*
* To select a different value for {decimals}, use {_setupDecimals}.
*
* All three of these values are immutable: they can only be set once during
* construction.
*/
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
_decimals = 18;
}
/**
* @dev Returns the name of the token.
*/
function name() public view returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5,05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
* called.
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
function decimals() public view returns (uint8) {
return _decimals;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view override returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view override returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `recipient` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(msg.sender, recipient, amount);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender) public view virtual override returns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
_approve(msg.sender, spender, amount);
return true;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP. See the note at the beginning of {ERC20}.
*
* Requirements:
*
* - `sender` and `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
* - the caller must have allowance for ``sender``'s tokens of at least
* `amount`.
*/
function transferFrom(
address sender,
address recipient,
uint256 amount
) public virtual override returns (bool) {
_transfer(sender, recipient, amount);
_approve(
sender,
msg.sender,
_allowances[sender][msg.sender].sub(amount, Errors.ERC20_TRANSFER_EXCEEDS_ALLOWANCE)
);
return true;
}
/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
_approve(msg.sender, spender, _allowances[msg.sender][spender].add(addedValue));
return true;
}
/**
* @dev Atomically decreases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
_approve(
msg.sender,
spender,
_allowances[msg.sender][spender].sub(subtractedValue, Errors.ERC20_DECREASED_ALLOWANCE_BELOW_ZERO)
);
return true;
}
/**
* @dev Moves tokens `amount` from `sender` to `recipient`.
*
* This is internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `sender` cannot be the zero address.
* - `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
*/
function _transfer(
address sender,
address recipient,
uint256 amount
) internal virtual {
_require(sender != address(0), Errors.ERC20_TRANSFER_FROM_ZERO_ADDRESS);
_require(recipient != address(0), Errors.ERC20_TRANSFER_TO_ZERO_ADDRESS);
_beforeTokenTransfer(sender, recipient, amount);
_balances[sender] = _balances[sender].sub(amount, Errors.ERC20_TRANSFER_EXCEEDS_BALANCE);
_balances[recipient] = _balances[recipient].add(amount);
emit Transfer(sender, recipient, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements:
*
* - `to` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal virtual {
_require(account != address(0), Errors.ERC20_MINT_TO_ZERO_ADDRESS);
_beforeTokenTransfer(address(0), account, amount);
_totalSupply = _totalSupply.add(amount);
_balances[account] = _balances[account].add(amount);
emit Transfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/
function _burn(address account, uint256 amount) internal virtual {
_require(account != address(0), Errors.ERC20_BURN_FROM_ZERO_ADDRESS);
_beforeTokenTransfer(account, address(0), amount);
_balances[account] = _balances[account].sub(amount, Errors.ERC20_BURN_EXCEEDS_ALLOWANCE);
_totalSupply = _totalSupply.sub(amount);
emit Transfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(
address owner,
address spender,
uint256 amount
) internal virtual {
_require(owner != address(0), Errors.ERC20_APPROVE_FROM_ZERO_ADDRESS);
_require(spender != address(0), Errors.ERC20_APPROVE_TO_ZERO_ADDRESS);
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Sets {decimals} to a value other than the default one of 18.
*
* WARNING: This function should only be called from the constructor. Most
* applications that interact with token contracts will not expect
* {decimals} to ever change, and may work incorrectly if it does.
*/
function _setupDecimals(uint8 decimals_) internal {
_decimals = decimals_;
}
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be to transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual {}
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
import "./LogExpMath.sol";
import "../helpers/BalancerErrors.sol";
/* solhint-disable private-vars-leading-underscore */
library FixedPoint {
uint256 internal constant ONE = 1e18; // 18 decimal places
uint256 internal constant MAX_POW_RELATIVE_ERROR = 10000; // 10^(-14)
// Minimum base for the power function when the exponent is 'free' (larger than ONE).
uint256 internal constant MIN_POW_BASE_FREE_EXPONENT = 0.7e18;
function add(uint256 a, uint256 b) internal pure returns (uint256) {
// Fixed Point addition is the same as regular checked addition
uint256 c = a + b;
_require(c >= a, Errors.ADD_OVERFLOW);
return c;
}
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
// Fixed Point addition is the same as regular checked addition
_require(b <= a, Errors.SUB_OVERFLOW);
uint256 c = a - b;
return c;
}
function mulDown(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 product = a * b;
_require(a == 0 || product / a == b, Errors.MUL_OVERFLOW);
return product / ONE;
}
function mulUp(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 product = a * b;
_require(a == 0 || product / a == b, Errors.MUL_OVERFLOW);
if (product == 0) {
return 0;
} else {
// The traditional divUp formula is:
// divUp(x, y) := (x + y - 1) / y
// To avoid intermediate overflow in the addition, we distribute the division and get:
// divUp(x, y) := (x - 1) / y + 1
// Note that this requires x != 0, which we already tested for.
return ((product - 1) / ONE) + 1;
}
}
function divDown(uint256 a, uint256 b) internal pure returns (uint256) {
_require(b != 0, Errors.ZERO_DIVISION);
if (a == 0) {
return 0;
} else {
uint256 aInflated = a * ONE;
_require(aInflated / a == ONE, Errors.DIV_INTERNAL); // mul overflow
return aInflated / b;
}
}
function divUp(uint256 a, uint256 b) internal pure returns (uint256) {
_require(b != 0, Errors.ZERO_DIVISION);
if (a == 0) {
return 0;
} else {
uint256 aInflated = a * ONE;
_require(aInflated / a == ONE, Errors.DIV_INTERNAL); // mul overflow
// The traditional divUp formula is:
// divUp(x, y) := (x + y - 1) / y
// To avoid intermediate overflow in the addition, we distribute the division and get:
// divUp(x, y) := (x - 1) / y + 1
// Note that this requires x != 0, which we already tested for.
return ((aInflated - 1) / b) + 1;
}
}
/**
* @dev Returns x^y, assuming both are fixed point numbers, rounding down. The result is guaranteed to not be above
* the true value (that is, the error function expected - actual is always positive).
*/
function powDown(uint256 x, uint256 y) internal pure returns (uint256) {
uint256 raw = LogExpMath.pow(x, y);
uint256 maxError = add(mulUp(raw, MAX_POW_RELATIVE_ERROR), 1);
if (raw < maxError) {
return 0;
} else {
return sub(raw, maxError);
}
}
/**
* @dev Returns x^y, assuming both are fixed point numbers, rounding up. The result is guaranteed to not be below
* the true value (that is, the error function expected - actual is always negative).
*/
function powUp(uint256 x, uint256 y) internal pure returns (uint256) {
uint256 raw = LogExpMath.pow(x, y);
uint256 maxError = add(mulUp(raw, MAX_POW_RELATIVE_ERROR), 1);
return add(raw, maxError);
}
/**
* @dev Returns the complement of a value (1 - x), capped to 0 if x is larger than 1.
*
* Useful when computing the complement for values with some level of relative error, as it strips this error and
* prevents intermediate negative values.
*/
function complement(uint256 x) internal pure returns (uint256) {
return (x < ONE) ? (ONE - x) : 0;
}
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General 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 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;
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;
pragma experimental ABIEncoderV2;
import "./IVault.sol";
import "./IPoolSwapStructs.sol";
/**
* @dev Interface for adding and removing liquidity that all Pool contracts should implement. Note that this is not
* the complete Pool contract interface, as it is missing the swap hooks. Pool contracts should also inherit from
* either IGeneralPool or IMinimalSwapInfoPool
*/
interface IBasePool is IPoolSwapStructs {
/**
* @dev Called by the Vault when a user calls `IVault.joinPool` to add liquidity to this Pool. Returns how many of
* each registered token the user should provide, as well as the amount of protocol fees the Pool owes to the Vault.
* The Vault will then take tokens from `sender` and add them to the Pool's balances, as well as collect
* the reported amount in protocol fees, which the pool should calculate based on `protocolSwapFeePercentage`.
*
* Protocol fees are reported and charged on join events so that the Pool is free of debt whenever new users join.
*
* `sender` is the account performing the join (from which tokens will be withdrawn), and `recipient` is the account
* designated to receive any benefits (typically pool shares). `currentBalances` contains the total balances
* for each token the Pool registered in the Vault, in the same order that `IVault.getPoolTokens` would return.
*
* `lastChangeBlock` is the last block in which *any* of the Pool's registered tokens last changed its total
* balance.
*
* `userData` contains any pool-specific instructions needed to perform the calculations, such as the type of
* join (e.g., proportional given an amount of pool shares, single-asset, multi-asset, etc.)
*
* Contracts implementing this function should check that the caller is indeed the Vault before performing any
* state-changing operations, such as minting pool shares.
*/
function onJoinPool(
bytes32 poolId,
address sender,
address recipient,
uint256[] memory balances,
uint256 lastChangeBlock,
uint256 protocolSwapFeePercentage,
bytes memory userData
) external returns (uint256[] memory amountsIn, uint256[] memory dueProtocolFeeAmounts);
/**
* @dev Called by the Vault when a user calls `IVault.exitPool` to remove liquidity from this Pool. Returns how many
* tokens the Vault should deduct from the Pool's balances, as well as the amount of protocol fees the Pool owes
* to the Vault. The Vault will then take tokens from the Pool's balances and send them to `recipient`,
* as well as collect the reported amount in protocol fees, which the Pool should calculate based on
* `protocolSwapFeePercentage`.
*
* Protocol fees are charged on exit events to guarantee that users exiting the Pool have paid their share.
*
* `sender` is the account performing the exit (typically the pool shareholder), and `recipient` is the account
* to which the Vault will send the proceeds. `currentBalances` contains the total token balances for each token
* the Pool registered in the Vault, in the same order that `IVault.getPoolTokens` would return.
*
* `lastChangeBlock` is the last block in which *any* of the Pool's registered tokens last changed its total
* balance.
*
* `userData` contains any pool-specific instructions needed to perform the calculations, such as the type of
* exit (e.g., proportional given an amount of pool shares, single-asset, multi-asset, etc.)
*
* Contracts implementing this function should check that the caller is indeed the Vault before performing any
* state-changing operations, such as burning pool shares.
*/
function onExitPool(
bytes32 poolId,
address sender,
address recipient,
uint256[] memory balances,
uint256 lastChangeBlock,
uint256 protocolSwapFeePercentage,
bytes memory userData
) external returns (uint256[] memory amountsOut, uint256[] memory dueProtocolFeeAmounts);
}
// SPDX-License-Identifier: 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: MIT
pragma solidity ^0.7.0;
/**
* @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
* https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
*
* Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
* presenting a message signed by the account. By not relying on `{IERC20-approve}`, the token holder account doesn't
* need to send a transaction, and thus is not required to hold Ether at all.
*/
interface IERC20Permit {
/**
* @dev Sets `value` as the allowance of `spender` over `owner`'s tokens,
* given `owner`'s signed approval.
*
* IMPORTANT: The same issues {IERC20-approve} has related to transaction
* ordering also apply here.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `deadline` must be a timestamp in the future.
* - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
* over the EIP712-formatted function arguments.
* - the signature must use ``owner``'s current nonce (see {nonces}).
*
* For more information on the signature format, see the
* https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
* section].
*/
function permit(
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) external;
/**
* @dev Returns the current nonce for `owner`. This value must be
* included whenever a signature is generated for {permit}.
*
* Every successful call to {permit} increases ``owner``'s nonce by one. This
* prevents a signature from being used multiple times.
*/
function nonces(address owner) external view returns (uint256);
/**
* @dev Returns the domain separator used in the encoding of the signature for `permit`, as defined by {EIP712}.
*/
// solhint-disable-next-line func-name-mixedcase
function DOMAIN_SEPARATOR() external view returns (bytes32);
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
// Inspired by Aave Protocol's IFlashLoanReceiver.
import "../../lib/openzeppelin/IERC20.sol";
interface IFlashLoanRecipient {
/**
* @dev When `flashLoan` is called on the Vault, it invokes the `receiveFlashLoan` hook on the recipient.
*
* At the time of the call, the Vault will have transferred `amounts` for `tokens` to the recipient. Before this
* call returns, the recipient must have transferred `amounts` plus `feeAmounts` for each token back to the
* Vault, or else the entire flash loan will revert.
*
* `userData` is the same value passed in the `IVault.flashLoan` call.
*/
function receiveFlashLoan(
IERC20[] memory tokens,
uint256[] memory amounts,
uint256[] memory feeAmounts,
bytes memory userData
) external;
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
pragma experimental ABIEncoderV2;
import "./IBasePool.sol";
/**
* @dev Pool contracts with the MinimalSwapInfo or TwoToken specialization settings should implement this interface.
*
* This is called by the Vault when a user calls `IVault.swap` or `IVault.batchSwap` to swap with this Pool.
* Returns the number of tokens the Pool will grant to the user in a 'given in' swap, or that the user will grant
* to the pool in a 'given out' swap.
*
* This can often be implemented by a `view` function, since many pricing algorithms don't need to track state
* changes in swaps. However, contracts implementing this in non-view functions should check that the caller is
* indeed the Vault.
*/
interface IMinimalSwapInfoPool is IBasePool {
function onSwap(
SwapRequest memory swapRequest,
uint256 currentBalanceTokenIn,
uint256 currentBalanceTokenOut
) external returns (uint256 amount);
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
pragma experimental ABIEncoderV2;
import "../../lib/openzeppelin/IERC20.sol";
import "./IVault.sol";
interface IPoolSwapStructs {
// This is not really an interface - it just defines common structs used by other interfaces: IGeneralPool and
// IMinimalSwapInfoPool.
//
// This data structure represents a request for a token swap, where `kind` indicates the swap type ('given in' or
// 'given out') which indicates whether or not the amount sent by the pool is known.
//
// The pool receives `tokenIn` and sends `tokenOut`. `amount` is the number of `tokenIn` tokens the pool will take
// in, or the number of `tokenOut` tokens the Pool will send out, depending on the given swap `kind`.
//
// All other fields are not strictly necessary for most swaps, but are provided to support advanced scenarios in
// some Pools.
//
// `poolId` is the ID of the Pool involved in the swap - this is useful for Pool contracts that implement more than
// one Pool.
//
// The meaning of `lastChangeBlock` depends on the Pool specialization:
// - Two Token or Minimal Swap Info: the last block in which either `tokenIn` or `tokenOut` changed its total
// balance.
// - General: the last block in which *any* of the Pool's registered tokens changed its total balance.
//
// `from` is the origin address for the funds the Pool receives, and `to` is the destination address
// where the Pool sends the outgoing tokens.
//
// `userData` is extra data provided by the caller - typically a signature from a trusted party.
struct SwapRequest {
IVault.SwapKind kind;
IERC20 tokenIn;
IERC20 tokenOut;
uint256 amount;
// Misc data
bytes32 poolId;
uint256 lastChangeBlock;
address from;
address to;
bytes userData;
}
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
pragma experimental ABIEncoderV2;
/**
* @dev Interface for querying historical data from a Pool that can be used as a Price Oracle.
*
* This lets third parties retrieve average prices of tokens held by a Pool over a given period of time, as well as the
* price of the Pool share token (BPT) and invariant. Since the invariant is a sensible measure of Pool liquidity, it
* can be used to compare two different price sources, and choose the most liquid one.
*
* Once the oracle is fully initialized, all queries are guaranteed to succeed as long as they require no data that
* is not older than the largest safe query window.
*/
interface IPriceOracle {
// The three values that can be queried:
//
// - PAIR_PRICE: the price of the tokens in the Pool, expressed as the price of the second token in units of the
// first token. For example, if token A is worth $2, and token B is worth $4, the pair price will be 2.0.
// Note that the price is computed *including* the tokens decimals. This means that the pair price of a Pool with
// DAI and USDC will be close to 1.0, despite DAI having 18 decimals and USDC 6.
//
// - BPT_PRICE: the price of the Pool share token (BPT), in units of the first token.
// Note that the price is computed *including* the tokens decimals. This means that the BPT price of a Pool with
// USDC in which BPT is worth $5 will be 5.0, despite the BPT having 18 decimals and USDC 6.
//
// - INVARIANT: the value of the Pool's invariant, which serves as a measure of its liquidity.
enum Variable { PAIR_PRICE, BPT_PRICE, INVARIANT }
/**
* @dev Returns the time average weighted price corresponding to each of `queries`. Prices are represented as 18
* decimal fixed point values.
*/
function getTimeWeightedAverage(OracleAverageQuery[] memory queries)
external
view
returns (uint256[] memory results);
/**
* @dev Returns latest sample of `variable`. Prices are represented as 18 decimal fixed point values.
*/
function getLatest(Variable variable) external view returns (uint256);
/**
* @dev Information for a Time Weighted Average query.
*
* Each query computes the average over a window of duration `secs` seconds that ended `ago` seconds ago. For
* example, the average over the past 30 minutes is computed by settings secs to 1800 and ago to 0. If secs is 1800
* and ago is 1800 as well, the average between 60 and 30 minutes ago is computed instead.
*/
struct OracleAverageQuery {
Variable variable;
uint256 secs;
uint256 ago;
}
/**
* @dev Returns largest time window that can be safely queried, where 'safely' means the Oracle is guaranteed to be
* able to produce a result and not revert.
*
* If a query has a non-zero `ago` value, then `secs + ago` (the oldest point in time) must be smaller than this
* value for 'safe' queries.
*/
function getLargestSafeQueryWindow() external view returns (uint256);
/**
* @dev Returns the accumulators corresponding to each of `queries`.
*/
function getPastAccumulators(OracleAccumulatorQuery[] memory queries)
external
view
returns (int256[] memory results);
/**
* @dev Information for an Accumulator query.
*
* Each query estimates the accumulator at a time `ago` seconds ago.
*/
struct OracleAccumulatorQuery {
Variable variable;
uint256 ago;
}
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
/**
* @dev Interface for the SignatureValidator helper, used to support meta-transactions.
*/
interface ISignaturesValidator {
/**
* @dev Returns the EIP712 domain separator.
*/
function getDomainSeparator() external view returns (bytes32);
/**
* @dev Returns the next nonce used by an address to sign messages.
*/
function getNextNonce(address user) external view returns (uint256);
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
/**
* @dev Interface for the TemporarilyPausable helper.
*/
interface ITemporarilyPausable {
/**
* @dev Emitted every time the pause state changes by `_setPaused`.
*/
event PausedStateChanged(bool paused);
/**
* @dev Returns the current paused state.
*/
function getPausedState()
external
view
returns (
bool paused,
uint256 pauseWindowEndTime,
uint256 bufferPeriodEndTime
);
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma experimental ABIEncoderV2;
import "../../lib/openzeppelin/IERC20.sol";
import "./IWETH.sol";
import "./IAsset.sol";
import "./IAuthorizer.sol";
import "./IFlashLoanRecipient.sol";
import "../ProtocolFeesCollector.sol";
import "../../lib/helpers/ISignaturesValidator.sol";
import "../../lib/helpers/ITemporarilyPausable.sol";
pragma solidity ^0.7.0;
/**
* @dev Full external interface for the Vault core contract - no external or public methods exist in the contract that
* don't override one of these declarations.
*/
interface IVault is ISignaturesValidator, ITemporarilyPausable {
// Generalities about the Vault:
//
// - Whenever documentation refers to 'tokens', it strictly refers to ERC20-compliant token contracts. Tokens are
// transferred out of the Vault by calling the `IERC20.transfer` function, and transferred in by calling
// `IERC20.transferFrom`. In these cases, the sender must have previously allowed the Vault to use their tokens by
// calling `IERC20.approve`. The only deviation from the ERC20 standard that is supported is functions not returning
// a boolean value: in these scenarios, a non-reverting call is assumed to be successful.
//
// - All non-view functions in the Vault are non-reentrant: calling them while another one is mid-execution (e.g.
// while execution control is transferred to a token contract during a swap) will result in a revert. View
// functions can be called in a re-reentrant way, but doing so might cause them to return inconsistent results.
// Contracts calling view functions in the Vault must make sure the Vault has not already been entered.
//
// - View functions revert if referring to either unregistered Pools, or unregistered tokens for registered Pools.
// Authorizer
//
// Some system actions are permissioned, like setting and collecting protocol fees. This permissioning system exists
// outside of the Vault in the Authorizer contract: the Vault simply calls the Authorizer to check if the caller
// can perform a given action.
/**
* @dev Returns the Vault's Authorizer.
*/
function getAuthorizer() external view returns (IAuthorizer);
/**
* @dev Sets a new Authorizer for the Vault. The caller must be allowed by the current Authorizer to do this.
*
* Emits an `AuthorizerChanged` event.
*/
function setAuthorizer(IAuthorizer newAuthorizer) external;
/**
* @dev Emitted when a new authorizer is set by `setAuthorizer`.
*/
event AuthorizerChanged(IAuthorizer indexed newAuthorizer);
// Relayers
//
// Additionally, it is possible for an account to perform certain actions on behalf of another one, using their
// Vault ERC20 allowance and Internal Balance. These accounts are said to be 'relayers' for these Vault functions,
// and are expected to be smart contracts with sound authentication mechanisms. For an account to be able to wield
// this power, two things must occur:
// - The Authorizer must grant the account the permission to be a relayer for the relevant Vault function. This
// means that Balancer governance must approve each individual contract to act as a relayer for the intended
// functions.
// - Each user must approve the relayer to act on their behalf.
// This double protection means users cannot be tricked into approving malicious relayers (because they will not
// have been allowed by the Authorizer via governance), nor can malicious relayers approved by a compromised
// Authorizer or governance drain user funds, since they would also need to be approved by each individual user.
/**
* @dev Returns true if `user` has approved `relayer` to act as a relayer for them.
*/
function hasApprovedRelayer(address user, address relayer) external view returns (bool);
/**
* @dev Allows `relayer` to act as a relayer for `sender` if `approved` is true, and disallows it otherwise.
*
* Emits a `RelayerApprovalChanged` event.
*/
function setRelayerApproval(
address sender,
address relayer,
bool approved
) external;
/**
* @dev Emitted every time a relayer is approved or disapproved by `setRelayerApproval`.
*/
event RelayerApprovalChanged(address indexed relayer, address indexed sender, bool approved);
// Internal Balance
//
// Users can deposit tokens into the Vault, where they are allocated to their Internal Balance, and later
// transferred or withdrawn. It can also be used as a source of tokens when joining Pools, as a destination
// when exiting them, and as either when performing swaps. This usage of Internal Balance results in greatly reduced
// gas costs when compared to relying on plain ERC20 transfers, leading to large savings for frequent users.
//
// Internal Balance management features batching, which means a single contract call can be used to perform multiple
// operations of different kinds, with different senders and recipients, at once.
/**
* @dev Returns `user`'s Internal Balance for a set of tokens.
*/
function getInternalBalance(address user, IERC20[] memory tokens) external view returns (uint256[] memory);
/**
* @dev Performs a set of user balance operations, which involve Internal Balance (deposit, withdraw or transfer)
* and plain ERC20 transfers using the Vault's allowance. This last feature is particularly useful for relayers, as
* it lets integrators reuse a user's Vault allowance.
*
* For each operation, if the caller is not `sender`, it must be an authorized relayer for them.
*/
function manageUserBalance(UserBalanceOp[] memory ops) external payable;
/**
* @dev Data for `manageUserBalance` operations, which include the possibility for ETH to be sent and received
without manual WETH wrapping or unwrapping.
*/
struct UserBalanceOp {
UserBalanceOpKind kind;
IAsset asset;
uint256 amount;
address sender;
address payable recipient;
}
// There are four possible operations in `manageUserBalance`:
//
// - DEPOSIT_INTERNAL
// Increases the Internal Balance of the `recipient` account by transferring tokens from the corresponding
// `sender`. The sender must have allowed the Vault to use their tokens via `IERC20.approve()`.
//
// ETH can be used by passing the ETH sentinel value as the asset and forwarding ETH in the call: it will be wrapped
// and deposited as WETH. Any ETH amount remaining will be sent back to the caller (not the sender, which is
// relevant for relayers).
//
// Emits an `InternalBalanceChanged` event.
//
//
// - WITHDRAW_INTERNAL
// Decreases the Internal Balance of the `sender` account by transferring tokens to the `recipient`.
//
// ETH can be used by passing the ETH sentinel value as the asset. This will deduct WETH instead, unwrap it and send
// it to the recipient as ETH.
//
// Emits an `InternalBalanceChanged` event.
//
//
// - TRANSFER_INTERNAL
// Transfers tokens from the Internal Balance of the `sender` account to the Internal Balance of `recipient`.
//
// Reverts if the ETH sentinel value is passed.
//
// Emits an `InternalBalanceChanged` event.
//
//
// - TRANSFER_EXTERNAL
// Transfers tokens from `sender` to `recipient`, using the Vault's ERC20 allowance. This is typically used by
// relayers, as it lets them reuse a user's Vault allowance.
//
// Reverts if the ETH sentinel value is passed.
//
// Emits an `ExternalBalanceTransfer` event.
enum UserBalanceOpKind { DEPOSIT_INTERNAL, WITHDRAW_INTERNAL, TRANSFER_INTERNAL, TRANSFER_EXTERNAL }
/**
* @dev Emitted when a user's Internal Balance changes, either from calls to `manageUserBalance`, or through
* interacting with Pools using Internal Balance.
*
* Because Internal Balance works exclusively with ERC20 tokens, ETH deposits and withdrawals will use the WETH
* address.
*/
event InternalBalanceChanged(address indexed user, IERC20 indexed token, int256 delta);
/**
* @dev Emitted when a user's Vault ERC20 allowance is used by the Vault to transfer tokens to an external account.
*/
event ExternalBalanceTransfer(IERC20 indexed token, address indexed sender, address recipient, uint256 amount);
// Pools
//
// There are three specialization settings for Pools, which allow for cheaper swaps at the cost of reduced
// functionality:
//
// - General: no specialization, suited for all Pools. IGeneralPool is used for swap request callbacks, passing the
// balance of all tokens in the Pool. These Pools have the largest swap costs (because of the extra storage reads),
// which increase with the number of registered tokens.
//
// - Minimal Swap Info: IMinimalSwapInfoPool is used instead of IGeneralPool, which saves gas by only passing the
// balance of the two tokens involved in the swap. This is suitable for some pricing algorithms, like the weighted
// constant product one popularized by Balancer V1. Swap costs are smaller compared to general Pools, and are
// independent of the number of registered tokens.
//
// - Two Token: only allows two tokens to be registered. This achieves the lowest possible swap gas cost. Like
// minimal swap info Pools, these are called via IMinimalSwapInfoPool.
enum PoolSpecialization { GENERAL, MINIMAL_SWAP_INFO, TWO_TOKEN }
/**
* @dev Registers the caller account as a Pool with a given specialization setting. Returns the Pool's ID, which
* is used in all Pool-related functions. Pools cannot be deregistered, nor can the Pool's specialization be
* changed.
*
* The caller is expected to be a smart contract that implements either `IGeneralPool` or `IMinimalSwapInfoPool`,
* depending on the chosen specialization setting. This contract is known as the Pool's contract.
*
* Note that the same contract may register itself as multiple Pools with unique Pool IDs, or in other words,
* multiple Pools may share the same contract.
*
* Emits a `PoolRegistered` event.
*/
function registerPool(PoolSpecialization specialization) external returns (bytes32);
/**
* @dev Emitted when a Pool is registered by calling `registerPool`.
*/
event PoolRegistered(bytes32 indexed poolId, address indexed poolAddress, PoolSpecialization specialization);
/**
* @dev Returns a Pool's contract address and specialization setting.
*/
function getPool(bytes32 poolId) external view returns (address, PoolSpecialization);
/**
* @dev Registers `tokens` for the `poolId` Pool. Must be called by the Pool's contract.
*
* Pools can only interact with tokens they have registered. Users join a Pool by transferring registered tokens,
* exit by receiving registered tokens, and can only swap registered tokens.
*
* Each token can only be registered once. For Pools with the Two Token specialization, `tokens` must have a length
* of two, that is, both tokens must be registered in the same `registerTokens` call, and they must be sorted in
* ascending order.
*
* The `tokens` and `assetManagers` arrays must have the same length, and each entry in these indicates the Asset
* Manager for the corresponding token. Asset Managers can manage a Pool's tokens via `managePoolBalance`,
* depositing and withdrawing them directly, and can even set their balance to arbitrary amounts. They are therefore
* expected to be highly secured smart contracts with sound design principles, and the decision to register an
* Asset Manager should not be made lightly.
*
* Pools can choose not to assign an Asset Manager to a given token by passing in the zero address. Once an Asset
* Manager is set, it cannot be changed except by deregistering the associated token and registering again with a
* different Asset Manager.
*
* Emits a `TokensRegistered` event.
*/
function registerTokens(
bytes32 poolId,
IERC20[] memory tokens,
address[] memory assetManagers
) external;
/**
* @dev Emitted when a Pool registers tokens by calling `registerTokens`.
*/
event TokensRegistered(bytes32 indexed poolId, IERC20[] tokens, address[] assetManagers);
/**
* @dev Deregisters `tokens` for the `poolId` Pool. Must be called by the Pool's contract.
*
* Only registered tokens (via `registerTokens`) can be deregistered. Additionally, they must have zero total
* balance. For Pools with the Two Token specialization, `tokens` must have a length of two, that is, both tokens
* must be deregistered in the same `deregisterTokens` call.
*
* A deregistered token can be re-registered later on, possibly with a different Asset Manager.
*
* Emits a `TokensDeregistered` event.
*/
function deregisterTokens(bytes32 poolId, IERC20[] memory tokens) external;
/**
* @dev Emitted when a Pool deregisters tokens by calling `deregisterTokens`.
*/
event TokensDeregistered(bytes32 indexed poolId, IERC20[] tokens);
/**
* @dev Returns detailed information for a Pool's registered token.
*
* `cash` is the number of tokens the Vault currently holds for the Pool. `managed` is the number of tokens
* withdrawn and held outside the Vault by the Pool's token Asset Manager. The Pool's total balance for `token`
* equals the sum of `cash` and `managed`.
*
* Internally, `cash` and `managed` are stored using 112 bits. No action can ever cause a Pool's token `cash`,
* `managed` or `total` balance to be greater than 2^112 - 1.
*
* `lastChangeBlock` is the number of the block in which `token`'s total balance was last modified (via either a
* join, exit, swap, or Asset Manager update). This value is useful to avoid so-called 'sandwich attacks', for
* example when developing price oracles. A change of zero (e.g. caused by a swap with amount zero) is considered a
* change for this purpose, and will update `lastChangeBlock`.
*
* `assetManager` is the Pool's token Asset Manager.
*/
function getPoolTokenInfo(bytes32 poolId, IERC20 token)
external
view
returns (
uint256 cash,
uint256 managed,
uint256 lastChangeBlock,
address assetManager
);
/**
* @dev Returns a Pool's registered tokens, the total balance for each, and the latest block when *any* of
* the tokens' `balances` changed.
*
* The order of the `tokens` array is the same order that will be used in `joinPool`, `exitPool`, as well as in all
* Pool hooks (where applicable). Calls to `registerTokens` and `deregisterTokens` may change this order.
*
* If a Pool only registers tokens once, and these are sorted in ascending order, they will be stored in the same
* order as passed to `registerTokens`.
*
* Total balances include both tokens held by the Vault and those withdrawn by the Pool's Asset Managers. These are
* the amounts used by joins, exits and swaps. For a detailed breakdown of token balances, use `getPoolTokenInfo`
* instead.
*/
function getPoolTokens(bytes32 poolId)
external
view
returns (
IERC20[] memory tokens,
uint256[] memory balances,
uint256 lastChangeBlock
);
/**
* @dev Called by users to join a Pool, which transfers tokens from `sender` into the Pool's balance. This will
* trigger custom Pool behavior, which will typically grant something in return to `recipient` - often tokenized
* Pool shares.
*
* If the caller is not `sender`, it must be an authorized relayer for them.
*
* The `assets` and `maxAmountsIn` arrays must have the same length, and each entry indicates the maximum amount
* to send for each asset. The amounts to send are decided by the Pool and not the Vault: it just enforces
* these maximums.
*
* If joining a Pool that holds WETH, it is possible to send ETH directly: the Vault will do the wrapping. To enable
* this mechanism, the IAsset sentinel value (the zero address) must be passed in the `assets` array instead of the
* WETH address. Note that it is not possible to combine ETH and WETH in the same join. Any excess ETH will be sent
* back to the caller (not the sender, which is important for relayers).
*
* `assets` must have the same length and order as the array returned by `getPoolTokens`. This prevents issues when
* interacting with Pools that register and deregister tokens frequently. If sending ETH however, the array must be
* sorted *before* replacing the WETH address with the ETH sentinel value (the zero address), which means the final
* `assets` array might not be sorted. Pools with no registered tokens cannot be joined.
*
* If `fromInternalBalance` is true, the caller's Internal Balance will be preferred: ERC20 transfers will only
* be made for the difference between the requested amount and Internal Balance (if any). Note that ETH cannot be
* withdrawn from Internal Balance: attempting to do so will trigger a revert.
*
* This causes the Vault to call the `IBasePool.onJoinPool` hook on the Pool's contract, where Pools implement
* their own custom logic. This typically requires additional information from the user (such as the expected number
* of Pool shares). This can be encoded in the `userData` argument, which is ignored by the Vault and passed
* directly to the Pool's contract, as is `recipient`.
*
* Emits a `PoolBalanceChanged` event.
*/
function joinPool(
bytes32 poolId,
address sender,
address recipient,
JoinPoolRequest memory request
) external payable;
struct JoinPoolRequest {
IAsset[] assets;
uint256[] maxAmountsIn;
bytes userData;
bool fromInternalBalance;
}
/**
* @dev Called by users to exit a Pool, which transfers tokens from the Pool's balance to `recipient`. This will
* trigger custom Pool behavior, which will typically ask for something in return from `sender` - often tokenized
* Pool shares. The amount of tokens that can be withdrawn is limited by the Pool's `cash` balance (see
* `getPoolTokenInfo`).
*
* If the caller is not `sender`, it must be an authorized relayer for them.
*
* The `tokens` and `minAmountsOut` arrays must have the same length, and each entry in these indicates the minimum
* token amount to receive for each token contract. The amounts to send are decided by the Pool and not the Vault:
* it just enforces these minimums.
*
* If exiting a Pool that holds WETH, it is possible to receive ETH directly: the Vault will do the unwrapping. To
* enable this mechanism, the IAsset sentinel value (the zero address) must be passed in the `assets` array instead
* of the WETH address. Note that it is not possible to combine ETH and WETH in the same exit.
*
* `assets` must have the same length and order as the array returned by `getPoolTokens`. This prevents issues when
* interacting with Pools that register and deregister tokens frequently. If receiving ETH however, the array must
* be sorted *before* replacing the WETH address with the ETH sentinel value (the zero address), which means the
* final `assets` array might not be sorted. Pools with no registered tokens cannot be exited.
*
* If `toInternalBalance` is true, the tokens will be deposited to `recipient`'s Internal Balance. Otherwise,
* an ERC20 transfer will be performed. Note that ETH cannot be deposited to Internal Balance: attempting to
* do so will trigger a revert.
*
* `minAmountsOut` is the minimum amount of tokens the user expects to get out of the Pool, for each token in the
* `tokens` array. This array must match the Pool's registered tokens.
*
* This causes the Vault to call the `IBasePool.onExitPool` hook on the Pool's contract, where Pools implement
* their own custom logic. This typically requires additional information from the user (such as the expected number
* of Pool shares to return). This can be encoded in the `userData` argument, which is ignored by the Vault and
* passed directly to the Pool's contract.
*
* Emits a `PoolBalanceChanged` event.
*/
function exitPool(
bytes32 poolId,
address sender,
address payable recipient,
ExitPoolRequest memory request
) external;
struct ExitPoolRequest {
IAsset[] assets;
uint256[] minAmountsOut;
bytes userData;
bool toInternalBalance;
}
/**
* @dev Emitted when a user joins or exits a Pool by calling `joinPool` or `exitPool`, respectively.
*/
event PoolBalanceChanged(
bytes32 indexed poolId,
address indexed liquidityProvider,
IERC20[] tokens,
int256[] deltas,
uint256[] protocolFeeAmounts
);
enum PoolBalanceChangeKind { JOIN, EXIT }
// Swaps
//
// Users can swap tokens with Pools by calling the `swap` and `batchSwap` functions. To do this,
// they need not trust Pool contracts in any way: all security checks are made by the Vault. They must however be
// aware of the Pools' pricing algorithms in order to estimate the prices Pools will quote.
//
// The `swap` function executes a single swap, while `batchSwap` can perform multiple swaps in sequence.
// In each individual swap, tokens of one kind are sent from the sender to the Pool (this is the 'token in'),
// and tokens of another kind are sent from the Pool to the recipient in exchange (this is the 'token out').
// More complex swaps, such as one token in to multiple tokens out can be achieved by batching together
// individual swaps.
//
// There are two swap kinds:
// - 'given in' swaps, where the amount of tokens in (sent to the Pool) is known, and the Pool determines (via the
// `onSwap` hook) the amount of tokens out (to send to the recipient).
// - 'given out' swaps, where the amount of tokens out (received from the Pool) is known, and the Pool determines
// (via the `onSwap` hook) the amount of tokens in (to receive from the sender).
//
// Additionally, it is possible to chain swaps using a placeholder input amount, which the Vault replaces with
// the calculated output of the previous swap. If the previous swap was 'given in', this will be the calculated
// tokenOut amount. If the previous swap was 'given out', it will use the calculated tokenIn amount. These extended
// swaps are known as 'multihop' swaps, since they 'hop' through a number of intermediate tokens before arriving at
// the final intended token.
//
// In all cases, tokens are only transferred in and out of the Vault (or withdrawn from and deposited into Internal
// Balance) after all individual swaps have been completed, and the net token balance change computed. This makes
// certain swap patterns, such as multihops, or swaps that interact with the same token pair in multiple Pools, cost
// much less gas than they would otherwise.
//
// It also means that under certain conditions it is possible to perform arbitrage by swapping with multiple
// Pools in a way that results in net token movement out of the Vault (profit), with no tokens being sent in (only
// updating the Pool's internal accounting).
//
// To protect users from front-running or the market changing rapidly, they supply a list of 'limits' for each token
// involved in the swap, where either the maximum number of tokens to send (by passing a positive value) or the
// minimum amount of tokens to receive (by passing a negative value) is specified.
//
// Additionally, a 'deadline' timestamp can also be provided, forcing the swap to fail if it occurs after
// this point in time (e.g. if the transaction failed to be included in a block promptly).
//
// If interacting with Pools that hold WETH, it is possible to both send and receive ETH directly: the Vault will do
// the wrapping and unwrapping. To enable this mechanism, the IAsset sentinel value (the zero address) must be
// passed in the `assets` array instead of the WETH address. Note that it is possible to combine ETH and WETH in the
// same swap. Any excess ETH will be sent back to the caller (not the sender, which is relevant for relayers).
//
// Finally, Internal Balance can be used when either sending or receiving tokens.
enum SwapKind { GIVEN_IN, GIVEN_OUT }
/**
* @dev Performs a swap with a single Pool.
*
* If the swap is 'given in' (the number of tokens to send to the Pool is known), it returns the amount of tokens
* taken from the Pool, which must be greater than or equal to `limit`.
*
* If the swap is 'given out' (the number of tokens to take from the Pool is known), it returns the amount of tokens
* sent to the Pool, which must be less than or equal to `limit`.
*
* Internal Balance usage and the recipient are determined by the `funds` struct.
*
* Emits a `Swap` event.
*/
function swap(
SingleSwap memory singleSwap,
FundManagement memory funds,
uint256 limit,
uint256 deadline
) external payable returns (uint256);
/**
* @dev Data for a single swap executed by `swap`. `amount` is either `amountIn` or `amountOut` depending on
* the `kind` value.
*
* `assetIn` and `assetOut` are either token addresses, or the IAsset sentinel value for ETH (the zero address).
* Note that Pools never interact with ETH directly: it will be wrapped to or unwrapped from WETH by the Vault.
*
* The `userData` field is ignored by the Vault, but forwarded to the Pool in the `onSwap` hook, and may be
* used to extend swap behavior.
*/
struct SingleSwap {
bytes32 poolId;
SwapKind kind;
IAsset assetIn;
IAsset assetOut;
uint256 amount;
bytes userData;
}
/**
* @dev Performs a series of swaps with one or multiple Pools. In each individual swap, the caller determines either
* the amount of tokens sent to or received from the Pool, depending on the `kind` value.
*
* Returns an array with the net Vault asset balance deltas. Positive amounts represent tokens (or ETH) sent to the
* Vault, and negative amounts represent tokens (or ETH) sent by the Vault. Each delta corresponds to the asset at
* the same index in the `assets` array.
*
* Swaps are executed sequentially, in the order specified by the `swaps` array. Each array element describes a
* Pool, the token to be sent to this Pool, the token to receive from it, and an amount that is either `amountIn` or
* `amountOut` depending on the swap kind.
*
* Multihop swaps can be executed by passing an `amount` value of zero for a swap. This will cause the amount in/out
* of the previous swap to be used as the amount in for the current one. In a 'given in' swap, 'tokenIn' must equal
* the previous swap's `tokenOut`. For a 'given out' swap, `tokenOut` must equal the previous swap's `tokenIn`.
*
* The `assets` array contains the addresses of all assets involved in the swaps. These are either token addresses,
* or the IAsset sentinel value for ETH (the zero address). Each entry in the `swaps` array specifies tokens in and
* out by referencing an index in `assets`. Note that Pools never interact with ETH directly: it will be wrapped to
* or unwrapped from WETH by the Vault.
*
* Internal Balance usage, sender, and recipient are determined by the `funds` struct. The `limits` array specifies
* the minimum or maximum amount of each token the vault is allowed to transfer.
*
* `batchSwap` can be used to make a single swap, like `swap` does, but doing so requires more gas than the
* equivalent `swap` call.
*
* Emits `Swap` events.
*/
function batchSwap(
SwapKind kind,
BatchSwapStep[] memory swaps,
IAsset[] memory assets,
FundManagement memory funds,
int256[] memory limits,
uint256 deadline
) external payable returns (int256[] memory);
/**
* @dev Data for each individual swap executed by `batchSwap`. The asset in and out fields are indexes into the
* `assets` array passed to that function, and ETH assets are converted to WETH.
*
* If `amount` is zero, the multihop mechanism is used to determine the actual amount based on the amount in/out
* from the previous swap, depending on the swap kind.
*
* The `userData` field is ignored by the Vault, but forwarded to the Pool in the `onSwap` hook, and may be
* used to extend swap behavior.
*/
struct BatchSwapStep {
bytes32 poolId;
uint256 assetInIndex;
uint256 assetOutIndex;
uint256 amount;
bytes userData;
}
/**
* @dev Emitted for each individual swap performed by `swap` or `batchSwap`.
*/
event Swap(
bytes32 indexed poolId,
IERC20 indexed tokenIn,
IERC20 indexed tokenOut,
uint256 amountIn,
uint256 amountOut
);
/**
* @dev All tokens in a swap are either sent from the `sender` account to the Vault, or from the Vault to the
* `recipient` account.
*
* If the caller is not `sender`, it must be an authorized relayer for them.
*
* If `fromInternalBalance` is true, the `sender`'s Internal Balance will be preferred, performing an ERC20
* transfer for the difference between the requested amount and the User's Internal Balance (if any). The `sender`
* must have allowed the Vault to use their tokens via `IERC20.approve()`. This matches the behavior of
* `joinPool`.
*
* If `toInternalBalance` is true, tokens will be deposited to `recipient`'s internal balance instead of
* transferred. This matches the behavior of `exitPool`.
*
* Note that ETH cannot be deposited to or withdrawn from Internal Balance: attempting to do so will trigger a
* revert.
*/
struct FundManagement {
address sender;
bool fromInternalBalance;
address payable recipient;
bool toInternalBalance;
}
/**
* @dev Simulates a call to `batchSwap`, returning an array of Vault asset deltas. Calls to `swap` cannot be
* simulated directly, but an equivalent `batchSwap` call can and will yield the exact same result.
*
* Each element in the array corresponds to the asset at the same index, and indicates the number of tokens (or ETH)
* the Vault would take from the sender (if positive) or send to the recipient (if negative). The arguments it
* receives are the same that an equivalent `batchSwap` call would receive.
*
* Unlike `batchSwap`, this function performs no checks on the sender or recipient field in the `funds` struct.
* This makes it suitable to be called by off-chain applications via eth_call without needing to hold tokens,
* approve them for the Vault, or even know a user's address.
*
* Note that this function is not 'view' (due to implementation details): the client code must explicitly execute
* eth_call instead of eth_sendTransaction.
*/
function queryBatchSwap(
SwapKind kind,
BatchSwapStep[] memory swaps,
IAsset[] memory assets,
FundManagement memory funds
) external returns (int256[] memory assetDeltas);
// Flash Loans
/**
* @dev Performs a 'flash loan', sending tokens to `recipient`, executing the `receiveFlashLoan` hook on it,
* and then reverting unless the tokens plus a proportional protocol fee have been returned.
*
* The `tokens` and `amounts` arrays must have the same length, and each entry in these indicates the loan amount
* for each token contract. `tokens` must be sorted in ascending order.
*
* The 'userData' field is ignored by the Vault, and forwarded as-is to `recipient` as part of the
* `receiveFlashLoan` call.
*
* Emits `FlashLoan` events.
*/
function flashLoan(
IFlashLoanRecipient recipient,
IERC20[] memory tokens,
uint256[] memory amounts,
bytes memory userData
) external;
/**
* @dev Emitted for each individual flash loan performed by `flashLoan`.
*/
event FlashLoan(IFlashLoanRecipient indexed recipient, IERC20 indexed token, uint256 amount, uint256 feeAmount);
// Asset Management
//
// Each token registered for a Pool can be assigned an Asset Manager, which is able to freely withdraw the Pool's
// tokens from the Vault, deposit them, or assign arbitrary values to its `managed` balance (see
// `getPoolTokenInfo`). This makes them extremely powerful and dangerous. Even if an Asset Manager only directly
// controls one of the tokens in a Pool, a malicious manager could set that token's balance to manipulate the
// prices of the other tokens, and then drain the Pool with swaps. The risk of using Asset Managers is therefore
// not constrained to the tokens they are managing, but extends to the entire Pool's holdings.
//
// However, a properly designed Asset Manager smart contract can be safely used for the Pool's benefit,
// for example by lending unused tokens out for interest, or using them to participate in voting protocols.
//
// This concept is unrelated to the IAsset interface.
/**
* @dev Performs a set of Pool balance operations, which may be either withdrawals, deposits or updates.
*
* Pool Balance management features batching, which means a single contract call can be used to perform multiple
* operations of different kinds, with different Pools and tokens, at once.
*
* For each operation, the caller must be registered as the Asset Manager for `token` in `poolId`.
*/
function managePoolBalance(PoolBalanceOp[] memory ops) external;
struct PoolBalanceOp {
PoolBalanceOpKind kind;
bytes32 poolId;
IERC20 token;
uint256 amount;
}
/**
* Withdrawals decrease the Pool's cash, but increase its managed balance, leaving the total balance unchanged.
*
* Deposits increase the Pool's cash, but decrease its managed balance, leaving the total balance unchanged.
*
* Updates don't affect the Pool's cash balance, but because the managed balance changes, it does alter the total.
* The external amount can be either increased or decreased by this call (i.e., reporting a gain or a loss).
*/
enum PoolBalanceOpKind { WITHDRAW, DEPOSIT, UPDATE }
/**
* @dev Emitted when a Pool's token Asset Manager alters its balance via `managePoolBalance`.
*/
event PoolBalanceManaged(
bytes32 indexed poolId,
address indexed assetManager,
IERC20 indexed token,
int256 cashDelta,
int256 managedDelta
);
// Protocol Fees
//
// Some operations cause the Vault to collect tokens in the form of protocol fees, which can then be withdrawn by
// permissioned accounts.
//
// There are two kinds of protocol fees:
//
// - flash loan fees: charged on all flash loans, as a percentage of the amounts lent.
//
// - swap fees: a percentage of the fees charged by Pools when performing swaps. For a number of reasons, including
// swap gas costs and interface simplicity, protocol swap fees are not charged on each individual swap. Rather,
// Pools are expected to keep track of how much they have charged in swap fees, and pay any outstanding debts to the
// Vault when they are joined or exited. This prevents users from joining a Pool with unpaid debt, as well as
// exiting a Pool in debt without first paying their share.
/**
* @dev Returns the current protocol fee module.
*/
function getProtocolFeesCollector() external view returns (ProtocolFeesCollector);
/**
* @dev Safety mechanism to pause most Vault operations in the event of an emergency - typically detection of an
* error in some part of the system.
*
* The Vault can only be paused during an initial time period, after which pausing is forever disabled.
*
* While the contract is paused, the following features are disabled:
* - depositing and transferring internal balance
* - transferring external balance (using the Vault's allowance)
* - swaps
* - joining Pools
* - Asset Manager interactions
*
* Internal Balance can still be withdrawn, and Pools exited.
*/
function setPaused(bool paused) external;
/**
* @dev Returns the Vault's WETH instance.
*/
function WETH() external view returns (IWETH);
// solhint-disable-previous-line func-name-mixedcase
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
import "../../lib/openzeppelin/IERC20.sol";
/**
* @dev Interface for the WETH token contract used internally for wrapping and unwrapping, to support
* sending and receiving ETH in joins, swaps, and internal balance deposits and withdrawals.
*/
interface IWETH is IERC20 {
function deposit() external payable;
function withdraw(uint256 amount) external;
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
interface IWeightedPoolPriceOracle {
/**
* @dev Returns the raw data of the sample at `index`.
*/
function getSample(uint256 index)
external
view
returns (
int256 logPairPrice,
int256 accLogPairPrice,
int256 logBptPrice,
int256 accLogBptPrice,
int256 logInvariant,
int256 accLogInvariant,
uint256 timestamp
);
/**
* @dev Returns the total number of samples.
*/
function getTotalSamples() external view returns (uint256);
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
import "../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
// 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 "../helpers/BalancerErrors.sol";
/* solhint-disable */
/**
* @dev Exponentiation and logarithm functions for 18 decimal fixed point numbers (both base and exponent/argument).
*
* Exponentiation and logarithm with arbitrary bases (x^y and log_x(y)) are implemented by conversion to natural
* exponentiation and logarithm (where the base is Euler's number).
*
* @author Fernando Martinelli - @fernandomartinelli
* @author Sergio Yuhjtman - @sergioyuhjtman
* @author Daniel Fernandez - @dmf7z
*/
library LogExpMath {
// All fixed point multiplications and divisions are inlined. This means we need to divide by ONE when multiplying
// two numbers, and multiply by ONE when dividing them.
// All arguments and return values are 18 decimal fixed point numbers.
int256 constant ONE_18 = 1e18;
// Internally, intermediate values are computed with higher precision as 20 decimal fixed point numbers, and in the
// case of ln36, 36 decimals.
int256 constant ONE_20 = 1e20;
int256 constant ONE_36 = 1e36;
// The domain of natural exponentiation is bound by the word size and number of decimals used.
//
// Because internally the result will be stored using 20 decimals, the largest possible result is
// (2^255 - 1) / 10^20, which makes the largest exponent ln((2^255 - 1) / 10^20) = 130.700829182905140221.
// The smallest possible result is 10^(-18), which makes largest negative argument
// ln(10^(-18)) = -41.446531673892822312.
// We use 130.0 and -41.0 to have some safety margin.
int256 constant MAX_NATURAL_EXPONENT = 130e18;
int256 constant MIN_NATURAL_EXPONENT = -41e18;
// Bounds for ln_36's argument. Both ln(0.9) and ln(1.1) can be represented with 36 decimal places in a fixed point
// 256 bit integer.
int256 constant LN_36_LOWER_BOUND = ONE_18 - 1e17;
int256 constant LN_36_UPPER_BOUND = ONE_18 + 1e17;
uint256 constant MILD_EXPONENT_BOUND = 2**254 / uint256(ONE_20);
// 18 decimal constants
int256 constant x0 = 128000000000000000000; // 2ˆ7
int256 constant a0 = 38877084059945950922200000000000000000000000000000000000; // eˆ(x0) (no decimals)
int256 constant x1 = 64000000000000000000; // 2ˆ6
int256 constant a1 = 6235149080811616882910000000; // eˆ(x1) (no decimals)
// 20 decimal constants
int256 constant x2 = 3200000000000000000000; // 2ˆ5
int256 constant a2 = 7896296018268069516100000000000000; // eˆ(x2)
int256 constant x3 = 1600000000000000000000; // 2ˆ4
int256 constant a3 = 888611052050787263676000000; // eˆ(x3)
int256 constant x4 = 800000000000000000000; // 2ˆ3
int256 constant a4 = 298095798704172827474000; // eˆ(x4)
int256 constant x5 = 400000000000000000000; // 2ˆ2
int256 constant a5 = 5459815003314423907810; // eˆ(x5)
int256 constant x6 = 200000000000000000000; // 2ˆ1
int256 constant a6 = 738905609893065022723; // eˆ(x6)
int256 constant x7 = 100000000000000000000; // 2ˆ0
int256 constant a7 = 271828182845904523536; // eˆ(x7)
int256 constant x8 = 50000000000000000000; // 2ˆ-1
int256 constant a8 = 164872127070012814685; // eˆ(x8)
int256 constant x9 = 25000000000000000000; // 2ˆ-2
int256 constant a9 = 128402541668774148407; // eˆ(x9)
int256 constant x10 = 12500000000000000000; // 2ˆ-3
int256 constant a10 = 113314845306682631683; // eˆ(x10)
int256 constant x11 = 6250000000000000000; // 2ˆ-4
int256 constant a11 = 106449445891785942956; // eˆ(x11)
/**
* @dev Exponentiation (x^y) with unsigned 18 decimal fixed point base and exponent.
*
* Reverts if ln(x) * y is smaller than `MIN_NATURAL_EXPONENT`, or larger than `MAX_NATURAL_EXPONENT`.
*/
function pow(uint256 x, uint256 y) internal pure returns (uint256) {
if (y == 0) {
// We solve the 0^0 indetermination by making it equal one.
return uint256(ONE_18);
}
if (x == 0) {
return 0;
}
// Instead of computing x^y directly, we instead rely on the properties of logarithms and exponentiation to
// arrive at that result. In particular, exp(ln(x)) = x, and ln(x^y) = y * ln(x). This means
// x^y = exp(y * ln(x)).
// The ln function takes a signed value, so we need to make sure x fits in the signed 256 bit range.
_require(x < 2**255, Errors.X_OUT_OF_BOUNDS);
int256 x_int256 = int256(x);
// We will compute y * ln(x) in a single step. Depending on the value of x, we can either use ln or ln_36. In
// both cases, we leave the division by ONE_18 (due to fixed point multiplication) to the end.
// This prevents y * ln(x) from overflowing, and at the same time guarantees y fits in the signed 256 bit range.
_require(y < MILD_EXPONENT_BOUND, Errors.Y_OUT_OF_BOUNDS);
int256 y_int256 = int256(y);
int256 logx_times_y;
if (LN_36_LOWER_BOUND < x_int256 && x_int256 < LN_36_UPPER_BOUND) {
int256 ln_36_x = _ln_36(x_int256);
// ln_36_x has 36 decimal places, so multiplying by y_int256 isn't as straightforward, since we can't just
// bring y_int256 to 36 decimal places, as it might overflow. Instead, we perform two 18 decimal
// multiplications and add the results: one with the first 18 decimals of ln_36_x, and one with the
// (downscaled) last 18 decimals.
logx_times_y = ((ln_36_x / ONE_18) * y_int256 + ((ln_36_x % ONE_18) * y_int256) / ONE_18);
} else {
logx_times_y = _ln(x_int256) * y_int256;
}
logx_times_y /= ONE_18;
// Finally, we compute exp(y * ln(x)) to arrive at x^y
_require(
MIN_NATURAL_EXPONENT <= logx_times_y && logx_times_y <= MAX_NATURAL_EXPONENT,
Errors.PRODUCT_OUT_OF_BOUNDS
);
return uint256(exp(logx_times_y));
}
/**
* @dev Natural exponentiation (e^x) with signed 18 decimal fixed point exponent.
*
* Reverts if `x` is smaller than MIN_NATURAL_EXPONENT, or larger than `MAX_NATURAL_EXPONENT`.
*/
function exp(int256 x) internal pure returns (int256) {
_require(x >= MIN_NATURAL_EXPONENT && x <= MAX_NATURAL_EXPONENT, Errors.INVALID_EXPONENT);
if (x < 0) {
// We only handle positive exponents: e^(-x) is computed as 1 / e^x. We can safely make x positive since it
// fits in the signed 256 bit range (as it is larger than MIN_NATURAL_EXPONENT).
// Fixed point division requires multiplying by ONE_18.
return ((ONE_18 * ONE_18) / exp(-x));
}
// First, we use the fact that e^(x+y) = e^x * e^y to decompose x into a sum of powers of two, which we call x_n,
// where x_n == 2^(7 - n), and e^x_n = a_n has been precomputed. We choose the first x_n, x0, to equal 2^7
// because all larger powers are larger than MAX_NATURAL_EXPONENT, and therefore not present in the
// decomposition.
// At the end of this process we will have the product of all e^x_n = a_n that apply, and the remainder of this
// decomposition, which will be lower than the smallest x_n.
// exp(x) = k_0 * a_0 * k_1 * a_1 * ... + k_n * a_n * exp(remainder), where each k_n equals either 0 or 1.
// We mutate x by subtracting x_n, making it the remainder of the decomposition.
// The first two a_n (e^(2^7) and e^(2^6)) are too large if stored as 18 decimal numbers, and could cause
// intermediate overflows. Instead we store them as plain integers, with 0 decimals.
// Additionally, x0 + x1 is larger than MAX_NATURAL_EXPONENT, which means they will not both be present in the
// decomposition.
// For each x_n, we test if that term is present in the decomposition (if x is larger than it), and if so deduct
// it and compute the accumulated product.
int256 firstAN;
if (x >= x0) {
x -= x0;
firstAN = a0;
} else if (x >= x1) {
x -= x1;
firstAN = a1;
} else {
firstAN = 1; // One with no decimal places
}
// We now transform x into a 20 decimal fixed point number, to have enhanced precision when computing the
// smaller terms.
x *= 100;
// `product` is the accumulated product of all a_n (except a0 and a1), which starts at 20 decimal fixed point
// one. Recall that fixed point multiplication requires dividing by ONE_20.
int256 product = ONE_20;
if (x >= x2) {
x -= x2;
product = (product * a2) / ONE_20;
}
if (x >= x3) {
x -= x3;
product = (product * a3) / ONE_20;
}
if (x >= x4) {
x -= x4;
product = (product * a4) / ONE_20;
}
if (x >= x5) {
x -= x5;
product = (product * a5) / ONE_20;
}
if (x >= x6) {
x -= x6;
product = (product * a6) / ONE_20;
}
if (x >= x7) {
x -= x7;
product = (product * a7) / ONE_20;
}
if (x >= x8) {
x -= x8;
product = (product * a8) / ONE_20;
}
if (x >= x9) {
x -= x9;
product = (product * a9) / ONE_20;
}
// x10 and x11 are unnecessary here since we have high enough precision already.
// Now we need to compute e^x, where x is small (in particular, it is smaller than x9). We use the Taylor series
// expansion for e^x: 1 + x + (x^2 / 2!) + (x^3 / 3!) + ... + (x^n / n!).
int256 seriesSum = ONE_20; // The initial one in the sum, with 20 decimal places.
int256 term; // Each term in the sum, where the nth term is (x^n / n!).
// The first term is simply x.
term = x;
seriesSum += term;
// Each term (x^n / n!) equals the previous one times x, divided by n. Since x is a fixed point number,
// multiplying by it requires dividing by ONE_20, but dividing by the non-fixed point n values does not.
term = ((term * x) / ONE_20) / 2;
seriesSum += term;
term = ((term * x) / ONE_20) / 3;
seriesSum += term;
term = ((term * x) / ONE_20) / 4;
seriesSum += term;
term = ((term * x) / ONE_20) / 5;
seriesSum += term;
term = ((term * x) / ONE_20) / 6;
seriesSum += term;
term = ((term * x) / ONE_20) / 7;
seriesSum += term;
term = ((term * x) / ONE_20) / 8;
seriesSum += term;
term = ((term * x) / ONE_20) / 9;
seriesSum += term;
term = ((term * x) / ONE_20) / 10;
seriesSum += term;
term = ((term * x) / ONE_20) / 11;
seriesSum += term;
term = ((term * x) / ONE_20) / 12;
seriesSum += term;
// 12 Taylor terms are sufficient for 18 decimal precision.
// We now have the first a_n (with no decimals), and the product of all other a_n present, and the Taylor
// approximation of the exponentiation of the remainder (both with 20 decimals). All that remains is to multiply
// all three (one 20 decimal fixed point multiplication, dividing by ONE_20, and one integer multiplication),
// and then drop two digits to return an 18 decimal value.
return (((product * seriesSum) / ONE_20) * firstAN) / 100;
}
/**
* @dev 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 "../helpers/BalancerErrors.sol";
/**
* @dev Wrappers over Solidity's arithmetic operations with added overflow checks.
* Adapted from OpenZeppelin's SafeMath library
*/
library Math {
/**
* @dev Returns the addition of two unsigned integers of 256 bits, reverting on overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
_require(c >= a, Errors.ADD_OVERFLOW);
return c;
}
/**
* @dev Returns the addition of two signed integers, reverting on overflow.
*/
function add(int256 a, int256 b) internal pure returns (int256) {
int256 c = a + b;
_require((b >= 0 && c >= a) || (b < 0 && c < a), Errors.ADD_OVERFLOW);
return c;
}
/**
* @dev Returns the subtraction of two unsigned integers of 256 bits, reverting on overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
_require(b <= a, Errors.SUB_OVERFLOW);
uint256 c = a - b;
return c;
}
/**
* @dev Returns the subtraction of two signed integers, reverting on overflow.
*/
function sub(int256 a, int256 b) internal pure returns (int256) {
int256 c = a - b;
_require((b >= 0 && c <= a) || (b < 0 && c > a), Errors.SUB_OVERFLOW);
return c;
}
/**
* @dev Returns the largest of two numbers of 256 bits.
*/
function max(uint256 a, uint256 b) internal pure returns (uint256) {
return a >= b ? a : b;
}
/**
* @dev Returns the smallest of two numbers of 256 bits.
*/
function min(uint256 a, uint256 b) internal pure returns (uint256) {
return a < b ? a : b;
}
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a * b;
_require(a == 0 || c / a == b, Errors.MUL_OVERFLOW);
return c;
}
function divDown(uint256 a, uint256 b) internal pure returns (uint256) {
_require(b != 0, Errors.ZERO_DIVISION);
return a / b;
}
function divUp(uint256 a, uint256 b) internal pure returns (uint256) {
_require(b != 0, Errors.ZERO_DIVISION);
if (a == 0) {
return 0;
} else {
return 1 + (a - 1) / b;
}
}
}
// SPDX-License-Identifier: 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 "./Buffer.sol";
import "./Samples.sol";
import "../../lib/helpers/BalancerErrors.sol";
import "./IWeightedPoolPriceOracle.sol";
import "../IPriceOracle.sol";
/**
* @dev This module allows Pools to access historical pricing information.
*
* It uses a 1024 long circular buffer to store past data, where the data within each sample is the result of
* accumulating live data for no more than two minutes. Therefore, assuming the worst case scenario where new data is
* updated in every single block, the oldest samples in the buffer (and therefore largest queryable period) will
* be slightly over 34 hours old.
*
* Usage of this module requires the caller to keep track of two variables: the latest circular buffer index, and the
* timestamp when the index last changed.
*/
contract PoolPriceOracle is IWeightedPoolPriceOracle {
using Buffer for uint256;
using Samples for bytes32;
// Each sample in the buffer accumulates information for up to 2 minutes. This is simply to reduce the size of the
// buffer: small time deviations will not have any significant effect.
// solhint-disable not-rely-on-time
uint256 private constant _MAX_SAMPLE_DURATION = 2 minutes;
// We use a mapping to simulate an array: the buffer won't grow or shrink, and since we will always use valid
// indexes using a mapping saves gas by skipping the bounds checks.
mapping(uint256 => bytes32) internal _samples;
function getSample(uint256 index)
external
view
override
returns (
int256 logPairPrice,
int256 accLogPairPrice,
int256 logBptPrice,
int256 accLogBptPrice,
int256 logInvariant,
int256 accLogInvariant,
uint256 timestamp
)
{
_require(index < Buffer.SIZE, Errors.ORACLE_INVALID_INDEX);
bytes32 sample = _getSample(index);
return sample.unpack();
}
function getTotalSamples() external pure override returns (uint256) {
return Buffer.SIZE;
}
/**
* @dev Processes new price and invariant data, updating the latest sample or creating a new one.
*
* Receives the new logarithms of values to store: `logPairPrice`, `logBptPrice` and `logInvariant`, as well the
* index of the latest sample and the timestamp of its creation.
*
* Returns the index of the latest sample. If different from `latestIndex`, the caller should also store the
* timestamp, and pass it on future calls to this function.
*/
function _processPriceData(
uint256 latestSampleCreationTimestamp,
uint256 latestIndex,
int256 logPairPrice,
int256 logBptPrice,
int256 logInvariant
) internal returns (uint256) {
// Read latest sample, and compute the next one by updating it with the newly received data.
bytes32 sample = _getSample(latestIndex).update(logPairPrice, logBptPrice, logInvariant, block.timestamp);
// We create a new sample if more than _MAX_SAMPLE_DURATION seconds have elapsed since the creation of the
// latest one. In other words, no sample accumulates data over a period larger than _MAX_SAMPLE_DURATION.
bool newSample = block.timestamp - latestSampleCreationTimestamp >= _MAX_SAMPLE_DURATION;
latestIndex = newSample ? latestIndex.next() : latestIndex;
// Store the updated or new sample.
_samples[latestIndex] = sample;
return latestIndex;
}
/**
* @dev Returns the instant value for `variable` in the sample pointed to by `index`.
*/
function _getInstantValue(IPriceOracle.Variable variable, uint256 index) internal view returns (int256) {
bytes32 sample = _getSample(index);
_require(sample.timestamp() > 0, Errors.ORACLE_NOT_INITIALIZED);
return sample.instant(variable);
}
/**
* @dev Returns the value of the accumulator for `variable` `ago` seconds ago. `latestIndex` must be the index of
* the latest sample in the buffer.
*
* Reverts under the following conditions:
* - if the buffer is empty.
* - if querying past information and the buffer has not been fully initialized.
* - if querying older information than available in the buffer. Note that a full buffer guarantees queries for the
* past 34 hours will not revert.
*
* If requesting information for a timestamp later than the latest one, it is extrapolated using the latest
* available data.
*
* When no exact information is available for the requested past timestamp (as usually happens, since at most one
* timestamp is stored every two minutes), it is estimated by performing linear interpolation using the closest
* values. This process is guaranteed to complete performing at most 10 storage reads.
*/
function _getPastAccumulator(
IPriceOracle.Variable variable,
uint256 latestIndex,
uint256 ago
) internal view returns (int256) {
// `ago` must not be before the epoch.
_require(block.timestamp >= ago, Errors.ORACLE_INVALID_SECONDS_QUERY);
uint256 lookUpTime = block.timestamp - ago;
bytes32 latestSample = _getSample(latestIndex);
uint256 latestTimestamp = latestSample.timestamp();
// The latest sample only has a non-zero timestamp if no data was ever processed and stored in the buffer.
_require(latestTimestamp > 0, Errors.ORACLE_NOT_INITIALIZED);
if (latestTimestamp <= lookUpTime) {
// The accumulator at times ahead of the latest one are computed by extrapolating the latest data. This is
// equivalent to the instant value not changing between the last timestamp and the look up time.
// We can use unchecked arithmetic since the accumulator can be represented in 53 bits, timestamps in 31
// bits, and the instant value in 22 bits.
uint256 elapsed = lookUpTime - latestTimestamp;
return latestSample.accumulator(variable) + (latestSample.instant(variable) * int256(elapsed));
} else {
// The look up time is before the latest sample, but we need to make sure that it is not before the oldest
// sample as well.
// Since we use a circular buffer, the oldest sample is simply the next one.
uint256 oldestIndex = latestIndex.next();
{
// Local scope used to prevent stack-too-deep errors.
bytes32 oldestSample = _getSample(oldestIndex);
uint256 oldestTimestamp = oldestSample.timestamp();
// For simplicity's sake, we only perform past queries if the buffer has been fully initialized. This
// means the oldest sample must have a non-zero timestamp.
_require(oldestTimestamp > 0, Errors.ORACLE_NOT_INITIALIZED);
// The only remaining condition to check is for the look up time to be between the oldest and latest
// timestamps.
_require(oldestTimestamp <= lookUpTime, Errors.ORACLE_QUERY_TOO_OLD);
}
// Perform binary search to find nearest samples to the desired timestamp.
(bytes32 prev, bytes32 next) = _findNearestSample(lookUpTime, oldestIndex);
// `next`'s timestamp is guaranteed to be larger than `prev`'s, so we can skip checked arithmetic.
uint256 samplesTimeDiff = next.timestamp() - prev.timestamp();
if (samplesTimeDiff > 0) {
// We estimate the accumulator at the requested look up time by interpolating linearly between the
// previous and next accumulators.
// We can use unchecked arithmetic since the accumulators can be represented in 53 bits, and timestamps
// in 31 bits.
int256 samplesAccDiff = next.accumulator(variable) - prev.accumulator(variable);
uint256 elapsed = lookUpTime - prev.timestamp();
return prev.accumulator(variable) + ((samplesAccDiff * int256(elapsed)) / int256(samplesTimeDiff));
} else {
// Rarely, one of the samples will have the exact requested look up time, which is indicated by `prev`
// and `next` being the same. In this case, we simply return the accumulator at that point in time.
return prev.accumulator(variable);
}
}
}
/**
* @dev Finds the two samples with timestamps before and after `lookUpDate`. If one of the samples matches exactly,
* both `prev` and `next` will be it. `offset` is the index of the oldest sample in the buffer.
*
* Assumes `lookUpDate` is greater or equal than the timestamp of the oldest sample, and less or equal than the
* timestamp of the latest sample.
*/
function _findNearestSample(uint256 lookUpDate, uint256 offset) internal view returns (bytes32 prev, bytes32 next) {
// We're going to perform a binary search in the circular buffer, which requires it to be sorted. To achieve
// this, we offset all buffer accesses by `offset`, making the first element the oldest one.
// Auxiliary variables in a typical binary search: we will look at some value `mid` between `low` and `high`,
// periodically increasing `low` or decreasing `high` until we either find a match or determine the element is
// not in the array.
uint256 low = 0;
uint256 high = Buffer.SIZE - 1;
uint256 mid;
// If the search fails and no sample has a timestamp of `lookUpDate` (as is the most common scenario), `sample`
// will be either the sample with the largest timestamp smaller than `lookUpDate`, or the one with the smallest
// timestamp larger than `lookUpDate`.
bytes32 sample;
uint256 sampleTimestamp;
while (low <= high) {
// Mid is the floor of the average.
uint256 midWithoutOffset = (high + low) / 2;
// Recall that the buffer is not actually sorted: we need to apply the offset to access it in a sorted way.
mid = midWithoutOffset.add(offset);
sample = _getSample(mid);
sampleTimestamp = sample.timestamp();
if (sampleTimestamp < lookUpDate) {
// If the mid sample is bellow the look up date, then increase the low index to start from there.
low = midWithoutOffset + 1;
} else if (sampleTimestamp > lookUpDate) {
// If the mid sample is above the look up date, then decrease the high index to start from there.
// We can skip checked arithmetic: it is impossible for `high` to ever be 0, as a scenario where `low`
// equals 0 and `high` equals 1 would result in `low` increasing to 1 in the previous `if` clause.
high = midWithoutOffset - 1;
} else {
// sampleTimestamp == lookUpDate
// If we have an exact match, return the sample as both `prev` and `next`.
return (sample, sample);
}
}
// In case we reach here, it means we didn't find exactly the sample we where looking for.
return sampleTimestamp < lookUpDate ? (sample, _getSample(mid.next())) : (_getSample(mid.prev()), sample);
}
/**
* @dev Returns the sample that corresponds to a given `index`.
*
* Using this function instead of accessing storage directly results in denser bytecode (since the storage slot is
* only computed here).
*/
function _getSample(uint256 index) internal view returns (bytes32) {
return _samples[index];
}
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
pragma experimental ABIEncoderV2;
import "../lib/openzeppelin/IERC20.sol";
import "../lib/helpers/InputHelpers.sol";
import "../lib/helpers/Authentication.sol";
import "../lib/openzeppelin/ReentrancyGuard.sol";
import "../lib/openzeppelin/SafeERC20.sol";
import "./interfaces/IVault.sol";
import "./interfaces/IAuthorizer.sol";
/**
* @dev This an auxiliary contract to the Vault, deployed by it during construction. It offloads some of the tasks the
* Vault performs to reduce its overall bytecode size.
*
* The current values for all protocol fee percentages are stored here, and any tokens charged as protocol fees are
* sent to this contract, where they may be withdrawn by authorized entities. All authorization tasks are delegated
* to the Vault's own authorizer.
*/
contract ProtocolFeesCollector is Authentication, ReentrancyGuard {
using SafeERC20 for IERC20;
// Absolute maximum fee percentages (1e18 = 100%, 1e16 = 1%).
uint256 private constant _MAX_PROTOCOL_SWAP_FEE_PERCENTAGE = 50e16; // 50%
uint256 private constant _MAX_PROTOCOL_FLASH_LOAN_FEE_PERCENTAGE = 1e16; // 1%
IVault public immutable vault;
// All fee percentages are 18-decimal fixed point numbers.
// The swap fee is charged whenever a swap occurs, as a percentage of the fee charged by the Pool. These are not
// actually charged on each individual swap: the `Vault` relies on the Pools being honest and reporting fees due
// when users join and exit them.
uint256 private _swapFeePercentage;
// The flash loan fee is charged whenever a flash loan occurs, as a percentage of the tokens lent.
uint256 private _flashLoanFeePercentage;
event SwapFeePercentageChanged(uint256 newSwapFeePercentage);
event FlashLoanFeePercentageChanged(uint256 newFlashLoanFeePercentage);
constructor(IVault _vault)
// The ProtocolFeesCollector is a singleton, so it simply uses its own address to disambiguate action
// identifiers.
Authentication(bytes32(uint256(address(this))))
{
vault = _vault;
}
function withdrawCollectedFees(
IERC20[] calldata tokens,
uint256[] calldata amounts,
address recipient
) external nonReentrant authenticate {
InputHelpers.ensureInputLengthMatch(tokens.length, amounts.length);
for (uint256 i = 0; i < tokens.length; ++i) {
IERC20 token = tokens[i];
uint256 amount = amounts[i];
token.safeTransfer(recipient, amount);
}
}
function setSwapFeePercentage(uint256 newSwapFeePercentage) external authenticate {
_require(newSwapFeePercentage <= _MAX_PROTOCOL_SWAP_FEE_PERCENTAGE, Errors.SWAP_FEE_PERCENTAGE_TOO_HIGH);
_swapFeePercentage = newSwapFeePercentage;
emit SwapFeePercentageChanged(newSwapFeePercentage);
}
function setFlashLoanFeePercentage(uint256 newFlashLoanFeePercentage) external authenticate {
_require(
newFlashLoanFeePercentage <= _MAX_PROTOCOL_FLASH_LOAN_FEE_PERCENTAGE,
Errors.FLASH_LOAN_FEE_PERCENTAGE_TOO_HIGH
);
_flashLoanFeePercentage = newFlashLoanFeePercentage;
emit FlashLoanFeePercentageChanged(newFlashLoanFeePercentage);
}
function getSwapFeePercentage() external view returns (uint256) {
return _swapFeePercentage;
}
function getFlashLoanFeePercentage() external view returns (uint256) {
return _flashLoanFeePercentage;
}
function getCollectedFeeAmounts(IERC20[] memory tokens) external view returns (uint256[] memory feeAmounts) {
feeAmounts = new uint256[](tokens.length);
for (uint256 i = 0; i < tokens.length; ++i) {
feeAmounts[i] = tokens[i].balanceOf(address(this));
}
}
function getAuthorizer() external view returns (IAuthorizer) {
return _getAuthorizer();
}
function _canPerform(bytes32 actionId, address account) internal view override returns (bool) {
return _getAuthorizer().canPerform(actionId, account, address(this));
}
function _getAuthorizer() internal view returns (IAuthorizer) {
return vault.getAuthorizer();
}
}
// SPDX-License-Identifier: 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 "../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
// 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 "../helpers/BalancerErrors.sol";
import "./IERC20.sol";
/**
* @title SafeERC20
* @dev Wrappers around ERC20 operations that throw on failure (when the token
* contract returns false). Tokens that return no value (and instead revert or
* throw on failure) are also supported, non-reverting calls are assumed to be
* successful.
* To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
library SafeERC20 {
function safeTransfer(
IERC20 token,
address to,
uint256 value
) internal {
_callOptionalReturn(address(token), abi.encodeWithSelector(token.transfer.selector, to, value));
}
function safeTransferFrom(
IERC20 token,
address from,
address to,
uint256 value
) internal {
_callOptionalReturn(address(token), abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
*
* WARNING: `token` is assumed to be a contract: calls to EOAs will *not* revert.
*/
function _callOptionalReturn(address token, bytes memory data) private {
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
// we're implementing it ourselves.
(bool success, bytes memory returndata) = token.call(data);
// If the low-level call didn't succeed we return whatever was returned from it.
assembly {
if eq(success, 0) {
returndatacopy(0, 0, returndatasize())
revert(0, returndatasize())
}
}
// Finally we check the returndata size is either zero or true - note that this check will always pass for EOAs
_require(returndata.length == 0 || abi.decode(returndata, (bool)), Errors.SAFE_ERC20_CALL_FAILED);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "../helpers/BalancerErrors.sol";
/**
* @dev Wrappers over Solidity's arithmetic operations with added overflow
* checks.
*
* Arithmetic operations in Solidity wrap on overflow. This can easily result
* in bugs, because programmers usually assume that an overflow raises an
* error, which is the standard behavior in high level programming languages.
* `SafeMath` restores this intuition by reverting the transaction when an
* operation overflows.
*
* Using this library instead of the unchecked operations eliminates an entire
* class of bugs, so it's recommended to use it always.
*/
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
*
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
_require(c >= a, Errors.ADD_OVERFLOW);
return c;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return sub(a, b, Errors.SUB_OVERFLOW);
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b, uint256 errorCode) internal pure returns (uint256) {
_require(b <= a, errorCode);
uint256 c = a - b;
return c;
}
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
import "../../lib/helpers/WordCodec.sol";
import "../IPriceOracle.sol";
/**
* @dev This library provides functions to help manipulating samples for Pool Price Oracles. It handles updates,
* encoding, and decoding of samples.
*
* Each sample holds the timestamp of its last update, plus information about three pieces of data: the price pair, the
* price of BPT (the associated Pool token), and the invariant.
*
* Prices and invariant are not stored directly: instead, we store their logarithm. These are known as the 'instant'
* values: the exact value at that timestamp.
*
* Additionally, for each value we keep an accumulator with the sum of all past values, each weighted by the time
* elapsed since the previous update. This lets us later subtract accumulators at different points in time and divide by
* the time elapsed between them, arriving at the geometric mean of the values (also known as log-average).
*
* All samples are stored in a single 256 bit word with the following structure:
*
* [ log pair price | bpt price | invariant ]
* [ instant | accumulator | instant | accumulator | instant | accumulator | timestamp ]
* [ int22 | int53 | int22 | int53 | int22 | int53 | uint31 ]
* MSB LSB
*
* Assuming the timestamp doesn't overflow (which holds until the year 2038), the largest elapsed time is 2^31, which
* means the largest possible accumulator value is 2^21 * 2^31, which can be represented using a signed 53 bit integer.
*/
library Samples {
using WordCodec for int256;
using WordCodec for uint256;
using WordCodec for bytes32;
uint256 internal constant _TIMESTAMP_OFFSET = 0;
uint256 internal constant _ACC_LOG_INVARIANT_OFFSET = 31;
uint256 internal constant _INST_LOG_INVARIANT_OFFSET = 84;
uint256 internal constant _ACC_LOG_BPT_PRICE_OFFSET = 106;
uint256 internal constant _INST_LOG_BPT_PRICE_OFFSET = 159;
uint256 internal constant _ACC_LOG_PAIR_PRICE_OFFSET = 181;
uint256 internal constant _INST_LOG_PAIR_PRICE_OFFSET = 234;
/**
* @dev Updates a sample, accumulating the new data based on the elapsed time since the previous update. Returns the
* updated sample.
*
* IMPORTANT: This function does not perform any arithmetic checks. In particular, it assumes the caller will never
* pass values that cannot be represented as 22 bit signed integers. Additionally, it also assumes
* `currentTimestamp` is greater than `sample`'s timestamp.
*/
function update(
bytes32 sample,
int256 instLogPairPrice,
int256 instLogBptPrice,
int256 instLogInvariant,
uint256 currentTimestamp
) internal pure returns (bytes32) {
// Because elapsed can be represented as a 31 bit unsigned integer, and the received values can be represented
// as 22 bit signed integers, we don't need to perform checked arithmetic.
int256 elapsed = int256(currentTimestamp - timestamp(sample));
int256 accLogPairPrice = _accLogPairPrice(sample) + instLogPairPrice * elapsed;
int256 accLogBptPrice = _accLogBptPrice(sample) + instLogBptPrice * elapsed;
int256 accLogInvariant = _accLogInvariant(sample) + instLogInvariant * elapsed;
return
pack(
instLogPairPrice,
accLogPairPrice,
instLogBptPrice,
accLogBptPrice,
instLogInvariant,
accLogInvariant,
currentTimestamp
);
}
/**
* @dev Returns the instant value stored in `sample` for `variable`.
*/
function instant(bytes32 sample, IPriceOracle.Variable variable) internal pure returns (int256) {
if (variable == IPriceOracle.Variable.PAIR_PRICE) {
return _instLogPairPrice(sample);
} else if (variable == IPriceOracle.Variable.BPT_PRICE) {
return _instLogBptPrice(sample);
} else {
// variable == IPriceOracle.Variable.INVARIANT
return _instLogInvariant(sample);
}
}
/**
* @dev Returns the accumulator value stored in `sample` for `variable`.
*/
function accumulator(bytes32 sample, IPriceOracle.Variable variable) internal pure returns (int256) {
if (variable == IPriceOracle.Variable.PAIR_PRICE) {
return _accLogPairPrice(sample);
} else if (variable == IPriceOracle.Variable.BPT_PRICE) {
return _accLogBptPrice(sample);
} else {
// variable == IPriceOracle.Variable.INVARIANT
return _accLogInvariant(sample);
}
}
/**
* @dev Returns `sample`'s timestamp.
*/
function timestamp(bytes32 sample) internal pure returns (uint256) {
return sample.decodeUint31(_TIMESTAMP_OFFSET);
}
/**
* @dev Returns `sample`'s instant value for the logarithm of the pair price.
*/
function _instLogPairPrice(bytes32 sample) private pure returns (int256) {
return sample.decodeInt22(_INST_LOG_PAIR_PRICE_OFFSET);
}
/**
* @dev Returns `sample`'s accumulator of the logarithm of the pair price.
*/
function _accLogPairPrice(bytes32 sample) private pure returns (int256) {
return sample.decodeInt53(_ACC_LOG_PAIR_PRICE_OFFSET);
}
/**
* @dev Returns `sample`'s instant value for the logarithm of the BPT price.
*/
function _instLogBptPrice(bytes32 sample) private pure returns (int256) {
return sample.decodeInt22(_INST_LOG_BPT_PRICE_OFFSET);
}
/**
* @dev Returns `sample`'s accumulator of the logarithm of the BPT price.
*/
function _accLogBptPrice(bytes32 sample) private pure returns (int256) {
return sample.decodeInt53(_ACC_LOG_BPT_PRICE_OFFSET);
}
/**
* @dev Returns `sample`'s instant value for the logarithm of the invariant.
*/
function _instLogInvariant(bytes32 sample) private pure returns (int256) {
return sample.decodeInt22(_INST_LOG_INVARIANT_OFFSET);
}
/**
* @dev Returns `sample`'s accumulator of the logarithm of the invariant.
*/
function _accLogInvariant(bytes32 sample) private pure returns (int256) {
return sample.decodeInt53(_ACC_LOG_INVARIANT_OFFSET);
}
/**
* @dev Returns a sample created by packing together its components.
*/
function pack(
int256 instLogPairPrice,
int256 accLogPairPrice,
int256 instLogBptPrice,
int256 accLogBptPrice,
int256 instLogInvariant,
int256 accLogInvariant,
uint256 _timestamp
) internal pure returns (bytes32) {
return
instLogPairPrice.encodeInt22(_INST_LOG_PAIR_PRICE_OFFSET) |
accLogPairPrice.encodeInt53(_ACC_LOG_PAIR_PRICE_OFFSET) |
instLogBptPrice.encodeInt22(_INST_LOG_BPT_PRICE_OFFSET) |
accLogBptPrice.encodeInt53(_ACC_LOG_BPT_PRICE_OFFSET) |
instLogInvariant.encodeInt22(_INST_LOG_INVARIANT_OFFSET) |
accLogInvariant.encodeInt53(_ACC_LOG_INVARIANT_OFFSET) |
_timestamp.encodeUint31(_TIMESTAMP_OFFSET);
}
/**
* @dev Unpacks a sample into its components.
*/
function unpack(bytes32 sample)
internal
pure
returns (
int256 logPairPrice,
int256 accLogPairPrice,
int256 logBptPrice,
int256 accLogBptPrice,
int256 logInvariant,
int256 accLogInvariant,
uint256 _timestamp
)
{
logPairPrice = _instLogPairPrice(sample);
accLogPairPrice = _accLogPairPrice(sample);
logBptPrice = _instLogBptPrice(sample);
accLogBptPrice = _accLogBptPrice(sample);
logInvariant = _instLogInvariant(sample);
accLogInvariant = _accLogInvariant(sample);
_timestamp = timestamp(sample);
}
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
import "./BalancerErrors.sol";
import "./ITemporarilyPausable.sol";
/**
* @dev Allows for a contract to be paused during an initial period after deployment, disabling functionality. Can be
* used as an emergency switch in case a security vulnerability or threat is identified.
*
* The contract can only be paused during the Pause Window, a period that starts at deployment. It can also be
* unpaused and repaused any number of times during this period. This is intended to serve as a safety measure: it lets
* system managers react quickly to potentially dangerous situations, knowing that this action is reversible if careful
* analysis later determines there was a false alarm.
*
* If the contract is paused when the Pause Window finishes, it will remain in the paused state through an additional
* Buffer Period, after which it will be automatically unpaused forever. This is to ensure there is always enough time
* to react to an emergency, even if the threat is discovered shortly before the Pause Window expires.
*
* Note that since the contract can only be paused within the Pause Window, unpausing during the Buffer Period is
* irreversible.
*/
abstract contract TemporarilyPausable is ITemporarilyPausable {
// The Pause Window and Buffer Period are timestamp-based: they should not be relied upon for sub-minute accuracy.
// solhint-disable not-rely-on-time
uint256 private constant _MAX_PAUSE_WINDOW_DURATION = 90 days;
uint256 private constant _MAX_BUFFER_PERIOD_DURATION = 30 days;
uint256 private immutable _pauseWindowEndTime;
uint256 private immutable _bufferPeriodEndTime;
bool private _paused;
constructor(uint256 pauseWindowDuration, uint256 bufferPeriodDuration) {
_require(pauseWindowDuration <= _MAX_PAUSE_WINDOW_DURATION, Errors.MAX_PAUSE_WINDOW_DURATION);
_require(bufferPeriodDuration <= _MAX_BUFFER_PERIOD_DURATION, Errors.MAX_BUFFER_PERIOD_DURATION);
uint256 pauseWindowEndTime = block.timestamp + pauseWindowDuration;
_pauseWindowEndTime = pauseWindowEndTime;
_bufferPeriodEndTime = pauseWindowEndTime + bufferPeriodDuration;
}
/**
* @dev Reverts if the contract is paused.
*/
modifier whenNotPaused() {
_ensureNotPaused();
_;
}
/**
* @dev Returns the current contract pause status, as well as the end times of the Pause Window and Buffer
* Period.
*/
function getPausedState()
external
view
override
returns (
bool paused,
uint256 pauseWindowEndTime,
uint256 bufferPeriodEndTime
)
{
paused = !_isNotPaused();
pauseWindowEndTime = _getPauseWindowEndTime();
bufferPeriodEndTime = _getBufferPeriodEndTime();
}
/**
* @dev Sets the pause state to `paused`. The contract can only be paused until the end of the Pause Window, and
* unpaused until the end of the Buffer Period.
*
* Once the Buffer Period expires, this function reverts unconditionally.
*/
function _setPaused(bool paused) internal {
if (paused) {
_require(block.timestamp < _getPauseWindowEndTime(), Errors.PAUSE_WINDOW_EXPIRED);
} else {
_require(block.timestamp < _getBufferPeriodEndTime(), Errors.BUFFER_PERIOD_EXPIRED);
}
_paused = paused;
emit PausedStateChanged(paused);
}
/**
* @dev Reverts if the contract is paused.
*/
function _ensureNotPaused() internal view {
_require(_isNotPaused(), Errors.PAUSED);
}
/**
* @dev Returns true if the contract is unpaused.
*
* Once the Buffer Period expires, the gas cost of calling this function is reduced dramatically, as storage is no
* longer accessed.
*/
function _isNotPaused() internal view returns (bool) {
// After the Buffer Period, the (inexpensive) timestamp check short-circuits the storage access.
return block.timestamp > _getBufferPeriodEndTime() || !_paused;
}
// These getters lead to reduced bytecode size by inlining the immutable variables in a single place.
function _getPauseWindowEndTime() private view returns (uint256) {
return _pauseWindowEndTime;
}
function _getBufferPeriodEndTime() private view returns (uint256) {
return _bufferPeriodEndTime;
}
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
import "../../lib/math/FixedPoint.sol";
import "../../lib/math/Math.sol";
import "../../lib/helpers/InputHelpers.sol";
/* solhint-disable private-vars-leading-underscore */
contract WeightedMath {
using FixedPoint for uint256;
// A minimum normalized weight imposes a maximum weight ratio. We need this due to limitations in the
// implementation of the power function, as these ratios are often exponents.
uint256 internal constant _MIN_WEIGHT = 0.01e18;
// Having a minimum normalized weight imposes a limit on the maximum number of tokens;
// i.e., the largest possible pool is one where all tokens have exactly the minimum weight.
uint256 internal constant _MAX_WEIGHTED_TOKENS = 100;
// Pool limits that arise from limitations in the fixed point power function (and the imposed 1:100 maximum weight
// ratio).
// Swap limits: amounts swapped may not be larger than this percentage of total balance.
uint256 internal constant _MAX_IN_RATIO = 0.3e18;
uint256 internal constant _MAX_OUT_RATIO = 0.3e18;
// Invariant growth limit: non-proportional joins cannot cause the invariant to increase by more than this ratio.
uint256 internal constant _MAX_INVARIANT_RATIO = 3e18;
// Invariant shrink limit: non-proportional exits cannot cause the invariant to decrease by less than this ratio.
uint256 internal constant _MIN_INVARIANT_RATIO = 0.7e18;
// Invariant is used to collect protocol swap fees by comparing its value between two times.
// So we can round always to the same direction. It is also used to initiate the BPT amount
// and, because there is a minimum BPT, we round down the invariant.
function _calculateInvariant(uint256[] memory normalizedWeights, uint256[] memory balances)
internal
pure
returns (uint256 invariant)
{
/**********************************************************************************************
// invariant _____ //
// wi = weight index i | | wi //
// bi = balance index i | | bi ^ = i //
// i = invariant //
**********************************************************************************************/
invariant = FixedPoint.ONE;
for (uint256 i = 0; i < normalizedWeights.length; i++) {
invariant = invariant.mulDown(balances[i].powDown(normalizedWeights[i]));
}
_require(invariant > 0, Errors.ZERO_INVARIANT);
}
// Computes how many tokens can be taken out of a pool if `amountIn` are sent, given the
// current balances and weights.
function _calcOutGivenIn(
uint256 balanceIn,
uint256 weightIn,
uint256 balanceOut,
uint256 weightOut,
uint256 amountIn
) internal pure returns (uint256) {
/**********************************************************************************************
// outGivenIn //
// aO = amountOut //
// bO = balanceOut //
// bI = balanceIn / / bI \ (wI / wO) \ //
// aI = amountIn aO = bO * | 1 - | -------------------------- | ^ | //
// wI = weightIn \ \ ( bI + aI ) / / //
// wO = weightOut //
**********************************************************************************************/
// Amount out, so we round down overall.
// The multiplication rounds down, and the subtrahend (power) rounds up (so the base rounds up too).
// Because bI / (bI + aI) <= 1, the exponent rounds down.
// Cannot exceed maximum in ratio
_require(amountIn <= balanceIn.mulDown(_MAX_IN_RATIO), Errors.MAX_IN_RATIO);
uint256 denominator = balanceIn.add(amountIn);
uint256 base = balanceIn.divUp(denominator);
uint256 exponent = weightIn.divDown(weightOut);
uint256 power = base.powUp(exponent);
return balanceOut.mulDown(power.complement());
}
// Computes how many tokens must be sent to a pool in order to take `amountOut`, given the
// current balances and weights.
function _calcInGivenOut(
uint256 balanceIn,
uint256 weightIn,
uint256 balanceOut,
uint256 weightOut,
uint256 amountOut
) internal pure returns (uint256) {
/**********************************************************************************************
// inGivenOut //
// aO = amountOut //
// bO = balanceOut //
// bI = balanceIn / / bO \ (wO / wI) \ //
// aI = amountIn aI = bI * | | -------------------------- | ^ - 1 | //
// wI = weightIn \ \ ( bO - aO ) / / //
// wO = weightOut //
**********************************************************************************************/
// Amount in, so we round up overall.
// The multiplication rounds up, and the power rounds up (so the base rounds up too).
// Because b0 / (b0 - a0) >= 1, the exponent rounds up.
// Cannot exceed maximum out ratio
_require(amountOut <= balanceOut.mulDown(_MAX_OUT_RATIO), Errors.MAX_OUT_RATIO);
uint256 base = balanceOut.divUp(balanceOut.sub(amountOut));
uint256 exponent = weightOut.divUp(weightIn);
uint256 power = base.powUp(exponent);
// Because the base is larger than one (and the power rounds up), the power should always be larger than one, so
// the following subtraction should never revert.
uint256 ratio = power.sub(FixedPoint.ONE);
return balanceIn.mulUp(ratio);
}
function _calcBptOutGivenExactTokensIn(
uint256[] memory balances,
uint256[] memory normalizedWeights,
uint256[] memory amountsIn,
uint256 bptTotalSupply,
uint256 swapFee
) internal pure returns (uint256) {
// BPT out, so we round down overall.
uint256[] memory balanceRatiosWithFee = new uint256[](amountsIn.length);
uint256 invariantRatioWithFees = 0;
for (uint256 i = 0; i < balances.length; i++) {
balanceRatiosWithFee[i] = balances[i].add(amountsIn[i]).divDown(balances[i]);
invariantRatioWithFees = invariantRatioWithFees.add(balanceRatiosWithFee[i].mulDown(normalizedWeights[i]));
}
uint256 invariantRatio = FixedPoint.ONE;
for (uint256 i = 0; i < balances.length; i++) {
uint256 amountInWithoutFee;
if (balanceRatiosWithFee[i] > invariantRatioWithFees) {
uint256 nonTaxableAmount = balances[i].mulDown(invariantRatioWithFees.sub(FixedPoint.ONE));
uint256 taxableAmount = amountsIn[i].sub(nonTaxableAmount);
amountInWithoutFee = nonTaxableAmount.add(taxableAmount.mulDown(FixedPoint.ONE.sub(swapFee)));
} else {
amountInWithoutFee = amountsIn[i];
}
uint256 balanceRatio = balances[i].add(amountInWithoutFee).divDown(balances[i]);
invariantRatio = invariantRatio.mulDown(balanceRatio.powDown(normalizedWeights[i]));
}
if (invariantRatio >= FixedPoint.ONE) {
return bptTotalSupply.mulDown(invariantRatio.sub(FixedPoint.ONE));
} else {
return 0;
}
}
function _calcTokenInGivenExactBptOut(
uint256 balance,
uint256 normalizedWeight,
uint256 bptAmountOut,
uint256 bptTotalSupply,
uint256 swapFee
) internal pure returns (uint256) {
/******************************************************************************************
// tokenInForExactBPTOut //
// a = amountIn //
// b = balance / / totalBPT + bptOut \ (1 / w) \ //
// bptOut = bptAmountOut a = b * | | -------------------------- | ^ - 1 | //
// bpt = totalBPT \ \ totalBPT / / //
// w = weight //
******************************************************************************************/
// Token in, so we round up overall.
// Calculate the factor by which the invariant will increase after minting BPTAmountOut
uint256 invariantRatio = bptTotalSupply.add(bptAmountOut).divUp(bptTotalSupply);
_require(invariantRatio <= _MAX_INVARIANT_RATIO, Errors.MAX_OUT_BPT_FOR_TOKEN_IN);
// Calculate by how much the token balance has to increase to match the invariantRatio
uint256 balanceRatio = invariantRatio.powUp(FixedPoint.ONE.divUp(normalizedWeight));
uint256 amountInWithoutFee = balance.mulUp(balanceRatio.sub(FixedPoint.ONE));
// We can now compute how much extra balance is being deposited and used in virtual swaps, and charge swap fees
// accordingly.
uint256 taxablePercentage = normalizedWeight.complement();
uint256 taxableAmount = amountInWithoutFee.mulUp(taxablePercentage);
uint256 nonTaxableAmount = amountInWithoutFee.sub(taxableAmount);
return nonTaxableAmount.add(taxableAmount.divUp(swapFee.complement()));
}
function _calcBptInGivenExactTokensOut(
uint256[] memory balances,
uint256[] memory normalizedWeights,
uint256[] memory amountsOut,
uint256 bptTotalSupply,
uint256 swapFee
) internal pure returns (uint256) {
// BPT in, so we round up overall.
uint256[] memory balanceRatiosWithoutFee = new uint256[](amountsOut.length);
uint256 invariantRatioWithoutFees = 0;
for (uint256 i = 0; i < balances.length; i++) {
balanceRatiosWithoutFee[i] = balances[i].sub(amountsOut[i]).divUp(balances[i]);
invariantRatioWithoutFees = invariantRatioWithoutFees.add(
balanceRatiosWithoutFee[i].mulUp(normalizedWeights[i])
);
}
uint256 invariantRatio = FixedPoint.ONE;
for (uint256 i = 0; i < balances.length; i++) {
// Swap fees are typically charged on 'token in', but there is no 'token in' here, so we apply it to
// 'token out'. This results in slightly larger price impact.
uint256 amountOutWithFee;
if (invariantRatioWithoutFees > balanceRatiosWithoutFee[i]) {
uint256 nonTaxableAmount = balances[i].mulDown(invariantRatioWithoutFees.complement());
uint256 taxableAmount = amountsOut[i].sub(nonTaxableAmount);
amountOutWithFee = nonTaxableAmount.add(taxableAmount.divUp(swapFee.complement()));
} else {
amountOutWithFee = amountsOut[i];
}
uint256 balanceRatio = balances[i].sub(amountOutWithFee).divDown(balances[i]);
invariantRatio = invariantRatio.mulDown(balanceRatio.powDown(normalizedWeights[i]));
}
return bptTotalSupply.mulUp(invariantRatio.complement());
}
function _calcTokenOutGivenExactBptIn(
uint256 balance,
uint256 normalizedWeight,
uint256 bptAmountIn,
uint256 bptTotalSupply,
uint256 swapFee
) internal pure returns (uint256) {
/*****************************************************************************************
// exactBPTInForTokenOut //
// a = amountOut //
// b = balance / / totalBPT - bptIn \ (1 / w) \ //
// bptIn = bptAmountIn a = b * | 1 - | -------------------------- | ^ | //
// bpt = totalBPT \ \ totalBPT / / //
// w = weight //
*****************************************************************************************/
// Token out, so we round down overall. The multiplication rounds down, but the power rounds up (so the base
// rounds up). Because (totalBPT - bptIn) / totalBPT <= 1, the exponent rounds down.
// Calculate the factor by which the invariant will decrease after burning BPTAmountIn
uint256 invariantRatio = bptTotalSupply.sub(bptAmountIn).divUp(bptTotalSupply);
_require(invariantRatio >= _MIN_INVARIANT_RATIO, Errors.MIN_BPT_IN_FOR_TOKEN_OUT);
// Calculate by how much the token balance has to decrease to match invariantRatio
uint256 balanceRatio = invariantRatio.powUp(FixedPoint.ONE.divDown(normalizedWeight));
// Because of rounding up, balanceRatio can be greater than one. Using complement prevents reverts.
uint256 amountOutWithoutFee = balance.mulDown(balanceRatio.complement());
// We can now compute how much excess balance is being withdrawn as a result of the virtual swaps, which result
// in swap fees.
uint256 taxablePercentage = normalizedWeight.complement();
// Swap fees are typically charged on 'token in', but there is no 'token in' here, so we apply it
// to 'token out'. This results in slightly larger price impact. Fees are rounded up.
uint256 taxableAmount = amountOutWithoutFee.mulUp(taxablePercentage);
uint256 nonTaxableAmount = amountOutWithoutFee.sub(taxableAmount);
return nonTaxableAmount.add(taxableAmount.mulDown(swapFee.complement()));
}
function _calcTokensOutGivenExactBptIn(
uint256[] memory balances,
uint256 bptAmountIn,
uint256 totalBPT
) internal pure returns (uint256[] memory) {
/**********************************************************************************************
// exactBPTInForTokensOut //
// (per token) //
// aO = amountOut / bptIn \ //
// b = balance a0 = b * | --------------------- | //
// bptIn = bptAmountIn \ totalBPT / //
// bpt = totalBPT //
**********************************************************************************************/
// Since we're computing an amount out, we round down overall. This means rounding down on both the
// multiplication and division.
uint256 bptRatio = bptAmountIn.divDown(totalBPT);
uint256[] memory amountsOut = new uint256[](balances.length);
for (uint256 i = 0; i < balances.length; i++) {
amountsOut[i] = balances[i].mulDown(bptRatio);
}
return amountsOut;
}
function _calcDueTokenProtocolSwapFeeAmount(
uint256 balance,
uint256 normalizedWeight,
uint256 previousInvariant,
uint256 currentInvariant,
uint256 protocolSwapFeePercentage
) internal pure returns (uint256) {
/*********************************************************************************
/* protocolSwapFeePercentage * balanceToken * ( 1 - (previousInvariant / currentInvariant) ^ (1 / weightToken))
*********************************************************************************/
if (currentInvariant <= previousInvariant) {
// This shouldn't happen outside of rounding errors, but have this safeguard nonetheless to prevent the Pool
// from entering a locked state in which joins and exits revert while computing accumulated swap fees.
return 0;
}
// We round down to prevent issues in the Pool's accounting, even if it means paying slightly less in protocol
// fees to the Vault.
// Fee percentage and balance multiplications round down, while the subtrahend (power) rounds up (as does the
// base). Because previousInvariant / currentInvariant <= 1, the exponent rounds down.
uint256 base = previousInvariant.divUp(currentInvariant);
uint256 exponent = FixedPoint.ONE.divDown(normalizedWeight);
// Because the exponent is larger than one, the base of the power function has a lower bound. We cap to this
// value to avoid numeric issues, which means in the extreme case (where the invariant growth is larger than
// 1 / min exponent) the Pool will pay less in protocol fees than it should.
base = Math.max(base, FixedPoint.MIN_POW_BASE_FREE_EXPONENT);
uint256 power = base.powUp(exponent);
uint256 tokenAccruedFees = balance.mulDown(power.complement());
return tokenAccruedFees.mulDown(protocolSwapFeePercentage);
}
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
import "../../lib/math//LogExpMath.sol";
import "../../lib/math/FixedPoint.sol";
import "../../lib/math/Math.sol";
import "../../lib/helpers/InputHelpers.sol";
/* solhint-disable private-vars-leading-underscore */
contract WeightedOracleMath {
using FixedPoint for uint256;
int256 private constant _LOG_COMPRESSION_FACTOR = 1e14;
int256 private constant _HALF_LOG_COMPRESSION_FACTOR = 0.5e14;
/**
* @dev Calculates the logarithm of the spot price of token B in token A.
*
* The return value is a 4 decimal fixed-point number: use `_fromLowResLog` to recover the original value.
*/
function _calcLogSpotPrice(
uint256 normalizedWeightA,
uint256 balanceA,
uint256 normalizedWeightB,
uint256 balanceB
) internal pure returns (int256) {
// Max balances are 2^112 and min weights are 0.01, so the division never overflows.
// The rounding direction is irrelevant as we're about to introduce a much larger error when converting to log
// space. We use `divUp` as it prevents the result from being zero, which would make the logarithm revert. A
// result of zero is therefore only possible with zero balances, which are prevented via other means.
uint256 spotPrice = balanceA.divUp(normalizedWeightA).divUp(balanceB.divUp(normalizedWeightB));
return _toLowResLog(spotPrice);
}
/**
* @dev Calculates the price of BPT in a token. `logBptTotalSupply` should be the result of calling `_toLowResLog`
* with the current BPT supply.
*
* The return value is a 4 decimal fixed-point number: use `_fromLowResLog` to recover the original value.
*/
function _calcLogBPTPrice(
uint256 normalizedWeight,
uint256 balance,
int256 logBptTotalSupply
) internal pure returns (int256) {
// BPT price = (balance / weight) / total supply
// Since we already have ln(total supply) and want to compute ln(BPT price), we perform the computation in log
// space directly: ln(BPT price) = ln(balance / weight) - ln(total supply)
// The rounding direction is irrelevant as we're about to introduce a much larger error when converting to log
// space. We use `divUp` as it prevents the result from being zero, which would make the logarithm revert. A
// result of zero is therefore only possible with zero balances, which are prevented via other means.
int256 logBalanceOverWeight = _toLowResLog(balance.divUp(normalizedWeight));
// Because we're subtracting two values in log space, this value has a larger error (+-0.0001 instead of
// +-0.00005), which results in a final larger relative error of around 0.1%.
return logBalanceOverWeight - logBptTotalSupply;
}
/**
* @dev Returns the natural logarithm of `value`, dropping most of the decimal places to arrive at a value that,
* when passed to `_fromLowResLog`, will have a maximum relative error of ~0.05% compared to `value`.
*
* Values returned from this function should not be mixed with other fixed-point values (as they have a different
* number of digits), but can be added or subtracted. Use `_fromLowResLog` to undo this process and return to an
* 18 decimal places fixed point value.
*
* Because so much precision is lost, the logarithmic values can be stored using much fewer bits than the original
* value required.
*/
function _toLowResLog(uint256 value) internal pure returns (int256) {
int256 ln = LogExpMath.ln(int256(value));
// Rounding division for signed numerator
return
(ln > 0 ? ln + _HALF_LOG_COMPRESSION_FACTOR : ln - _HALF_LOG_COMPRESSION_FACTOR) / _LOG_COMPRESSION_FACTOR;
}
/**
* @dev Restores `value` from logarithmic space. `value` is expected to be the result of a call to `_toLowResLog`,
* any other function that returns 4 decimals fixed point logarithms, or the sum of such values.
*/
function _fromLowResLog(int256 value) internal pure returns (uint256) {
return uint256(LogExpMath.exp(value * _LOG_COMPRESSION_FACTOR));
}
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
pragma experimental ABIEncoderV2;
import "../../lib/math/FixedPoint.sol";
import "../../lib/helpers/InputHelpers.sol";
import "../BaseMinimalSwapInfoPool.sol";
import "./WeightedMath.sol";
import "./WeightedPoolUserDataHelpers.sol";
// This contract relies on tons of immutable state variables to perform efficient lookup, without resorting to storage
// reads. Because immutable arrays are not supported, we instead declare a fixed set of state variables plus total
// count, resulting in a large number of state variables.
contract WeightedPool is BaseMinimalSwapInfoPool, WeightedMath {
using FixedPoint for uint256;
using WeightedPoolUserDataHelpers for bytes;
// The protocol fees will always be charged using the token associated with the max weight in the pool.
// Since these Pools will register tokens only once, we can assume this index will be constant.
uint256 private immutable _maxWeightTokenIndex;
uint256 private immutable _normalizedWeight0;
uint256 private immutable _normalizedWeight1;
uint256 private immutable _normalizedWeight2;
uint256 private immutable _normalizedWeight3;
uint256 private immutable _normalizedWeight4;
uint256 private immutable _normalizedWeight5;
uint256 private immutable _normalizedWeight6;
uint256 private immutable _normalizedWeight7;
uint256 private _lastInvariant;
enum JoinKind { INIT, EXACT_TOKENS_IN_FOR_BPT_OUT, TOKEN_IN_FOR_EXACT_BPT_OUT }
enum ExitKind { EXACT_BPT_IN_FOR_ONE_TOKEN_OUT, EXACT_BPT_IN_FOR_TOKENS_OUT, BPT_IN_FOR_EXACT_TOKENS_OUT }
constructor(
IVault vault,
string memory name,
string memory symbol,
IERC20[] memory tokens,
uint256[] memory normalizedWeights,
uint256 swapFeePercentage,
uint256 pauseWindowDuration,
uint256 bufferPeriodDuration,
address owner
)
BaseMinimalSwapInfoPool(
vault,
name,
symbol,
tokens,
swapFeePercentage,
pauseWindowDuration,
bufferPeriodDuration,
owner
)
{
uint256 numTokens = tokens.length;
InputHelpers.ensureInputLengthMatch(numTokens, normalizedWeights.length);
// Ensure each normalized weight is above them minimum and find the token index of the maximum weight
uint256 normalizedSum = 0;
uint256 maxWeightTokenIndex = 0;
uint256 maxNormalizedWeight = 0;
for (uint8 i = 0; i < numTokens; i++) {
uint256 normalizedWeight = normalizedWeights[i];
_require(normalizedWeight >= _MIN_WEIGHT, Errors.MIN_WEIGHT);
normalizedSum = normalizedSum.add(normalizedWeight);
if (normalizedWeight > maxNormalizedWeight) {
maxWeightTokenIndex = i;
maxNormalizedWeight = normalizedWeight;
}
}
// Ensure that the normalized weights sum to ONE
_require(normalizedSum == FixedPoint.ONE, Errors.NORMALIZED_WEIGHT_INVARIANT);
_maxWeightTokenIndex = maxWeightTokenIndex;
_normalizedWeight0 = normalizedWeights.length > 0 ? normalizedWeights[0] : 0;
_normalizedWeight1 = normalizedWeights.length > 1 ? normalizedWeights[1] : 0;
_normalizedWeight2 = normalizedWeights.length > 2 ? normalizedWeights[2] : 0;
_normalizedWeight3 = normalizedWeights.length > 3 ? normalizedWeights[3] : 0;
_normalizedWeight4 = normalizedWeights.length > 4 ? normalizedWeights[4] : 0;
_normalizedWeight5 = normalizedWeights.length > 5 ? normalizedWeights[5] : 0;
_normalizedWeight6 = normalizedWeights.length > 6 ? normalizedWeights[6] : 0;
_normalizedWeight7 = normalizedWeights.length > 7 ? normalizedWeights[7] : 0;
}
function _normalizedWeight(IERC20 token) internal view virtual returns (uint256) {
// prettier-ignore
if (token == _token0) { return _normalizedWeight0; }
else if (token == _token1) { return _normalizedWeight1; }
else if (token == _token2) { return _normalizedWeight2; }
else if (token == _token3) { return _normalizedWeight3; }
else if (token == _token4) { return _normalizedWeight4; }
else if (token == _token5) { return _normalizedWeight5; }
else if (token == _token6) { return _normalizedWeight6; }
else if (token == _token7) { return _normalizedWeight7; }
else {
_revert(Errors.INVALID_TOKEN);
}
}
function _normalizedWeights() internal view virtual returns (uint256[] memory) {
uint256 totalTokens = _getTotalTokens();
uint256[] memory normalizedWeights = new uint256[](totalTokens);
// prettier-ignore
{
if (totalTokens > 0) { normalizedWeights[0] = _normalizedWeight0; } else { return normalizedWeights; }
if (totalTokens > 1) { normalizedWeights[1] = _normalizedWeight1; } else { return normalizedWeights; }
if (totalTokens > 2) { normalizedWeights[2] = _normalizedWeight2; } else { return normalizedWeights; }
if (totalTokens > 3) { normalizedWeights[3] = _normalizedWeight3; } else { return normalizedWeights; }
if (totalTokens > 4) { normalizedWeights[4] = _normalizedWeight4; } else { return normalizedWeights; }
if (totalTokens > 5) { normalizedWeights[5] = _normalizedWeight5; } else { return normalizedWeights; }
if (totalTokens > 6) { normalizedWeights[6] = _normalizedWeight6; } else { return normalizedWeights; }
if (totalTokens > 7) { normalizedWeights[7] = _normalizedWeight7; } else { return normalizedWeights; }
}
return normalizedWeights;
}
function getLastInvariant() external view returns (uint256) {
return _lastInvariant;
}
/**
* @dev Returns the current value of the invariant.
*/
function getInvariant() public view returns (uint256) {
(, uint256[] memory balances, ) = getVault().getPoolTokens(getPoolId());
// Since the Pool hooks always work with upscaled balances, we manually
// upscale here for consistency
_upscaleArray(balances, _scalingFactors());
uint256[] memory normalizedWeights = _normalizedWeights();
return WeightedMath._calculateInvariant(normalizedWeights, balances);
}
function getNormalizedWeights() external view returns (uint256[] memory) {
return _normalizedWeights();
}
// Base Pool handlers
// Swap
function _onSwapGivenIn(
SwapRequest memory swapRequest,
uint256 currentBalanceTokenIn,
uint256 currentBalanceTokenOut
) internal view virtual override whenNotPaused returns (uint256) {
// Swaps are disabled while the contract is paused.
return
WeightedMath._calcOutGivenIn(
currentBalanceTokenIn,
_normalizedWeight(swapRequest.tokenIn),
currentBalanceTokenOut,
_normalizedWeight(swapRequest.tokenOut),
swapRequest.amount
);
}
function _onSwapGivenOut(
SwapRequest memory swapRequest,
uint256 currentBalanceTokenIn,
uint256 currentBalanceTokenOut
) internal view virtual override whenNotPaused returns (uint256) {
// Swaps are disabled while the contract is paused.
return
WeightedMath._calcInGivenOut(
currentBalanceTokenIn,
_normalizedWeight(swapRequest.tokenIn),
currentBalanceTokenOut,
_normalizedWeight(swapRequest.tokenOut),
swapRequest.amount
);
}
// Initialize
function _onInitializePool(
bytes32,
address,
address,
bytes memory userData
) internal virtual override whenNotPaused returns (uint256, uint256[] memory) {
// It would be strange for the Pool to be paused before it is initialized, but for consistency we prevent
// initialization in this case.
WeightedPool.JoinKind kind = userData.joinKind();
_require(kind == WeightedPool.JoinKind.INIT, Errors.UNINITIALIZED);
uint256[] memory amountsIn = userData.initialAmountsIn();
InputHelpers.ensureInputLengthMatch(_getTotalTokens(), amountsIn.length);
_upscaleArray(amountsIn, _scalingFactors());
uint256[] memory normalizedWeights = _normalizedWeights();
uint256 invariantAfterJoin = WeightedMath._calculateInvariant(normalizedWeights, amountsIn);
// Set the initial BPT to the value of the invariant times the number of tokens. This makes BPT supply more
// consistent in Pools with similar compositions but different number of tokens.
uint256 bptAmountOut = Math.mul(invariantAfterJoin, _getTotalTokens());
_lastInvariant = invariantAfterJoin;
return (bptAmountOut, amountsIn);
}
// Join
function _onJoinPool(
bytes32,
address,
address,
uint256[] memory balances,
uint256,
uint256 protocolSwapFeePercentage,
bytes memory userData
)
internal
virtual
override
whenNotPaused
returns (
uint256,
uint256[] memory,
uint256[] memory
)
{
// All joins are disabled while the contract is paused.
uint256[] memory normalizedWeights = _normalizedWeights();
// Due protocol swap fee amounts are computed by measuring the growth of the invariant between the previous join
// or exit event and now - the invariant's growth is due exclusively to swap fees. This avoids spending gas
// computing them on each individual swap
uint256 invariantBeforeJoin = WeightedMath._calculateInvariant(normalizedWeights, balances);
uint256[] memory dueProtocolFeeAmounts = _getDueProtocolFeeAmounts(
balances,
normalizedWeights,
_lastInvariant,
invariantBeforeJoin,
protocolSwapFeePercentage
);
// Update current balances by subtracting the protocol fee amounts
_mutateAmounts(balances, dueProtocolFeeAmounts, FixedPoint.sub);
(uint256 bptAmountOut, uint256[] memory amountsIn) = _doJoin(balances, normalizedWeights, userData);
// Update the invariant with the balances the Pool will have after the join, in order to compute the
// protocol swap fee amounts due in future joins and exits.
_lastInvariant = _invariantAfterJoin(balances, amountsIn, normalizedWeights);
return (bptAmountOut, amountsIn, dueProtocolFeeAmounts);
}
function _doJoin(
uint256[] memory balances,
uint256[] memory normalizedWeights,
bytes memory userData
) private view returns (uint256, uint256[] memory) {
JoinKind kind = userData.joinKind();
if (kind == JoinKind.EXACT_TOKENS_IN_FOR_BPT_OUT) {
return _joinExactTokensInForBPTOut(balances, normalizedWeights, userData);
} else if (kind == JoinKind.TOKEN_IN_FOR_EXACT_BPT_OUT) {
return _joinTokenInForExactBPTOut(balances, normalizedWeights, userData);
} else {
_revert(Errors.UNHANDLED_JOIN_KIND);
}
}
function _joinExactTokensInForBPTOut(
uint256[] memory balances,
uint256[] memory normalizedWeights,
bytes memory userData
) private view returns (uint256, uint256[] memory) {
(uint256[] memory amountsIn, uint256 minBPTAmountOut) = userData.exactTokensInForBptOut();
InputHelpers.ensureInputLengthMatch(_getTotalTokens(), amountsIn.length);
_upscaleArray(amountsIn, _scalingFactors());
uint256 bptAmountOut = WeightedMath._calcBptOutGivenExactTokensIn(
balances,
normalizedWeights,
amountsIn,
totalSupply(),
_swapFeePercentage
);
_require(bptAmountOut >= minBPTAmountOut, Errors.BPT_OUT_MIN_AMOUNT);
return (bptAmountOut, amountsIn);
}
function _joinTokenInForExactBPTOut(
uint256[] memory balances,
uint256[] memory normalizedWeights,
bytes memory userData
) private view returns (uint256, uint256[] memory) {
(uint256 bptAmountOut, uint256 tokenIndex) = userData.tokenInForExactBptOut();
// Note that there is no maximum amountIn parameter: this is handled by `IVault.joinPool`.
_require(tokenIndex < _getTotalTokens(), Errors.OUT_OF_BOUNDS);
uint256[] memory amountsIn = new uint256[](_getTotalTokens());
amountsIn[tokenIndex] = WeightedMath._calcTokenInGivenExactBptOut(
balances[tokenIndex],
normalizedWeights[tokenIndex],
bptAmountOut,
totalSupply(),
_swapFeePercentage
);
return (bptAmountOut, amountsIn);
}
// Exit
function _onExitPool(
bytes32,
address,
address,
uint256[] memory balances,
uint256,
uint256 protocolSwapFeePercentage,
bytes memory userData
)
internal
virtual
override
returns (
uint256 bptAmountIn,
uint256[] memory amountsOut,
uint256[] memory dueProtocolFeeAmounts
)
{
// Exits are not completely disabled while the contract is paused: proportional exits (exact BPT in for tokens
// out) remain functional.
uint256[] memory normalizedWeights = _normalizedWeights();
if (_isNotPaused()) {
// Due protocol swap fee amounts are computed by measuring the growth of the invariant between the previous
// join or exit event and now - the invariant's growth is due exclusively to swap fees. This avoids
// spending gas calculating the fees on each individual swap.
uint256 invariantBeforeExit = WeightedMath._calculateInvariant(normalizedWeights, balances);
dueProtocolFeeAmounts = _getDueProtocolFeeAmounts(
balances,
normalizedWeights,
_lastInvariant,
invariantBeforeExit,
protocolSwapFeePercentage
);
// Update current balances by subtracting the protocol fee amounts
_mutateAmounts(balances, dueProtocolFeeAmounts, FixedPoint.sub);
} else {
// If the contract is paused, swap protocol fee amounts are not charged to avoid extra calculations and
// reduce the potential for errors.
dueProtocolFeeAmounts = new uint256[](_getTotalTokens());
}
(bptAmountIn, amountsOut) = _doExit(balances, normalizedWeights, userData);
// Update the invariant with the balances the Pool will have after the exit, in order to compute the
// protocol swap fees due in future joins and exits.
_lastInvariant = _invariantAfterExit(balances, amountsOut, normalizedWeights);
return (bptAmountIn, amountsOut, dueProtocolFeeAmounts);
}
function _doExit(
uint256[] memory balances,
uint256[] memory normalizedWeights,
bytes memory userData
) private view returns (uint256, uint256[] memory) {
ExitKind kind = userData.exitKind();
if (kind == ExitKind.EXACT_BPT_IN_FOR_ONE_TOKEN_OUT) {
return _exitExactBPTInForTokenOut(balances, normalizedWeights, userData);
} else if (kind == ExitKind.EXACT_BPT_IN_FOR_TOKENS_OUT) {
return _exitExactBPTInForTokensOut(balances, userData);
} else {
// ExitKind.BPT_IN_FOR_EXACT_TOKENS_OUT
return _exitBPTInForExactTokensOut(balances, normalizedWeights, userData);
}
}
function _exitExactBPTInForTokenOut(
uint256[] memory balances,
uint256[] memory normalizedWeights,
bytes memory userData
) private view whenNotPaused returns (uint256, uint256[] memory) {
// This exit function is disabled if the contract is paused.
(uint256 bptAmountIn, uint256 tokenIndex) = userData.exactBptInForTokenOut();
// Note that there is no minimum amountOut parameter: this is handled by `IVault.exitPool`.
_require(tokenIndex < _getTotalTokens(), Errors.OUT_OF_BOUNDS);
// We exit in a single token, so we initialize amountsOut with zeros
uint256[] memory amountsOut = new uint256[](_getTotalTokens());
// And then assign the result to the selected token
amountsOut[tokenIndex] = WeightedMath._calcTokenOutGivenExactBptIn(
balances[tokenIndex],
normalizedWeights[tokenIndex],
bptAmountIn,
totalSupply(),
_swapFeePercentage
);
return (bptAmountIn, amountsOut);
}
function _exitExactBPTInForTokensOut(uint256[] memory balances, bytes memory userData)
private
view
returns (uint256, uint256[] memory)
{
// This exit function is the only one that is not disabled if the contract is paused: it remains unrestricted
// in an attempt to provide users with a mechanism to retrieve their tokens in case of an emergency.
// This particular exit function is the only one that remains available because it is the simplest one, and
// therefore the one with the lowest likelihood of errors.
uint256 bptAmountIn = userData.exactBptInForTokensOut();
// Note that there is no minimum amountOut parameter: this is handled by `IVault.exitPool`.
uint256[] memory amountsOut = WeightedMath._calcTokensOutGivenExactBptIn(balances, bptAmountIn, totalSupply());
return (bptAmountIn, amountsOut);
}
function _exitBPTInForExactTokensOut(
uint256[] memory balances,
uint256[] memory normalizedWeights,
bytes memory userData
) private view whenNotPaused returns (uint256, uint256[] memory) {
// This exit function is disabled if the contract is paused.
(uint256[] memory amountsOut, uint256 maxBPTAmountIn) = userData.bptInForExactTokensOut();
InputHelpers.ensureInputLengthMatch(amountsOut.length, _getTotalTokens());
_upscaleArray(amountsOut, _scalingFactors());
uint256 bptAmountIn = WeightedMath._calcBptInGivenExactTokensOut(
balances,
normalizedWeights,
amountsOut,
totalSupply(),
_swapFeePercentage
);
_require(bptAmountIn <= maxBPTAmountIn, Errors.BPT_IN_MAX_AMOUNT);
return (bptAmountIn, amountsOut);
}
// Helpers
function _getDueProtocolFeeAmounts(
uint256[] memory balances,
uint256[] memory normalizedWeights,
uint256 previousInvariant,
uint256 currentInvariant,
uint256 protocolSwapFeePercentage
) private view returns (uint256[] memory) {
// Initialize with zeros
uint256[] memory dueProtocolFeeAmounts = new uint256[](_getTotalTokens());
// Early return if the protocol swap fee percentage is zero, saving gas.
if (protocolSwapFeePercentage == 0) {
return dueProtocolFeeAmounts;
}
// The protocol swap fees are always paid using the token with the largest weight in the Pool. As this is the
// token that is expected to have the largest balance, using it to pay fees should not unbalance the Pool.
dueProtocolFeeAmounts[_maxWeightTokenIndex] = WeightedMath._calcDueTokenProtocolSwapFeeAmount(
balances[_maxWeightTokenIndex],
normalizedWeights[_maxWeightTokenIndex],
previousInvariant,
currentInvariant,
protocolSwapFeePercentage
);
return dueProtocolFeeAmounts;
}
/**
* @dev Returns the value of the invariant given `balances`, assuming they are increased by `amountsIn`. All
* amounts are expected to be upscaled.
*/
function _invariantAfterJoin(
uint256[] memory balances,
uint256[] memory amountsIn,
uint256[] memory normalizedWeights
) private view returns (uint256) {
_mutateAmounts(balances, amountsIn, FixedPoint.add);
return WeightedMath._calculateInvariant(normalizedWeights, balances);
}
function _invariantAfterExit(
uint256[] memory balances,
uint256[] memory amountsOut,
uint256[] memory normalizedWeights
) private view returns (uint256) {
_mutateAmounts(balances, amountsOut, FixedPoint.sub);
return WeightedMath._calculateInvariant(normalizedWeights, balances);
}
/**
* @dev Mutates `amounts` by applying `mutation` with each entry in `arguments`.
*
* Equivalent to `amounts = amounts.map(mutation)`.
*/
function _mutateAmounts(
uint256[] memory toMutate,
uint256[] memory arguments,
function(uint256, uint256) pure returns (uint256) mutation
) private view {
for (uint256 i = 0; i < _getTotalTokens(); ++i) {
toMutate[i] = mutation(toMutate[i], arguments[i]);
}
}
/**
* @dev This function returns the appreciation of one BPT relative to the
* underlying tokens. This starts at 1 when the pool is created and grows over time
*/
function getRate() public view returns (uint256) {
// The initial BPT supply is equal to the invariant times the number of tokens.
return Math.mul(getInvariant(), _getTotalTokens()).divDown(totalSupply());
}
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
pragma experimental ABIEncoderV2;
import "../../lib/math/FixedPoint.sol";
import "../../lib/helpers/InputHelpers.sol";
import "../../lib/helpers/TemporarilyPausable.sol";
import "../../lib/openzeppelin/ERC20.sol";
import "./WeightedMath.sol";
import "./WeightedOracleMath.sol";
import "./WeightedPool2TokensMiscData.sol";
import "./WeightedPoolUserDataHelpers.sol";
import "../BalancerPoolToken.sol";
import "../BasePoolAuthorization.sol";
import "../oracle/PoolPriceOracle.sol";
import "../oracle/Buffer.sol";
import "../../vault/interfaces/IMinimalSwapInfoPool.sol";
import "../IPriceOracle.sol";
contract WeightedPool2Tokens is
IMinimalSwapInfoPool,
IPriceOracle,
BasePoolAuthorization,
BalancerPoolToken,
TemporarilyPausable,
PoolPriceOracle,
WeightedMath,
WeightedOracleMath
{
using FixedPoint for uint256;
using WeightedPoolUserDataHelpers for bytes;
using WeightedPool2TokensMiscData for bytes32;
uint256 private constant _MINIMUM_BPT = 1e6;
// 1e18 corresponds to 1.0, or a 100% fee
uint256 private constant _MIN_SWAP_FEE_PERCENTAGE = 1e12; // 0.0001%
uint256 private constant _MAX_SWAP_FEE_PERCENTAGE = 1e17; // 10%
// The swap fee is internally stored using 64 bits, which is enough to represent _MAX_SWAP_FEE_PERCENTAGE.
bytes32 internal _miscData;
uint256 private _lastInvariant;
IVault private immutable _vault;
bytes32 private immutable _poolId;
IERC20 internal immutable _token0;
IERC20 internal immutable _token1;
uint256 private immutable _normalizedWeight0;
uint256 private immutable _normalizedWeight1;
// The protocol fees will always be charged using the token associated with the max weight in the pool.
// Since these Pools will register tokens only once, we can assume this index will be constant.
uint256 private immutable _maxWeightTokenIndex;
// All token balances are normalized to behave as if the token had 18 decimals. We assume a token's decimals will
// not change throughout its lifetime, and store the corresponding scaling factor for each at construction time.
// These factors are always greater than or equal to one: tokens with more than 18 decimals are not supported.
uint256 internal immutable _scalingFactor0;
uint256 internal immutable _scalingFactor1;
event OracleEnabledChanged(bool enabled);
event SwapFeePercentageChanged(uint256 swapFeePercentage);
modifier onlyVault(bytes32 poolId) {
_require(msg.sender == address(getVault()), Errors.CALLER_NOT_VAULT);
_require(poolId == getPoolId(), Errors.INVALID_POOL_ID);
_;
}
struct NewPoolParams {
IVault vault;
string name;
string symbol;
IERC20 token0;
IERC20 token1;
uint256 normalizedWeight0;
uint256 normalizedWeight1;
uint256 swapFeePercentage;
uint256 pauseWindowDuration;
uint256 bufferPeriodDuration;
bool oracleEnabled;
address owner;
}
constructor(NewPoolParams memory params)
// Base Pools are expected to be deployed using factories. By using the factory address as the action
// disambiguator, we make all Pools deployed by the same factory share action identifiers. This allows for
// simpler management of permissions (such as being able to manage granting the 'set fee percentage' action in
// any Pool created by the same factory), while still making action identifiers unique among different factories
// if the selectors match, preventing accidental errors.
Authentication(bytes32(uint256(msg.sender)))
BalancerPoolToken(params.name, params.symbol)
BasePoolAuthorization(params.owner)
TemporarilyPausable(params.pauseWindowDuration, params.bufferPeriodDuration)
{
_setOracleEnabled(params.oracleEnabled);
_setSwapFeePercentage(params.swapFeePercentage);
bytes32 poolId = params.vault.registerPool(IVault.PoolSpecialization.TWO_TOKEN);
// Pass in zero addresses for Asset Managers
IERC20[] memory tokens = new IERC20[](2);
tokens[0] = params.token0;
tokens[1] = params.token1;
params.vault.registerTokens(poolId, tokens, new address[](2));
// Set immutable state variables - these cannot be read from during construction
_vault = params.vault;
_poolId = poolId;
_token0 = params.token0;
_token1 = params.token1;
_scalingFactor0 = _computeScalingFactor(params.token0);
_scalingFactor1 = _computeScalingFactor(params.token1);
// Ensure each normalized weight is above them minimum and find the token index of the maximum weight
_require(params.normalizedWeight0 >= _MIN_WEIGHT, Errors.MIN_WEIGHT);
_require(params.normalizedWeight1 >= _MIN_WEIGHT, Errors.MIN_WEIGHT);
// Ensure that the normalized weights sum to ONE
uint256 normalizedSum = params.normalizedWeight0.add(params.normalizedWeight1);
_require(normalizedSum == FixedPoint.ONE, Errors.NORMALIZED_WEIGHT_INVARIANT);
_normalizedWeight0 = params.normalizedWeight0;
_normalizedWeight1 = params.normalizedWeight1;
_maxWeightTokenIndex = params.normalizedWeight0 >= params.normalizedWeight1 ? 0 : 1;
}
// Getters / Setters
function getVault() public view returns (IVault) {
return _vault;
}
function getPoolId() public view returns (bytes32) {
return _poolId;
}
function getMiscData()
external
view
returns (
int256 logInvariant,
int256 logTotalSupply,
uint256 oracleSampleCreationTimestamp,
uint256 oracleIndex,
bool oracleEnabled,
uint256 swapFeePercentage
)
{
bytes32 miscData = _miscData;
logInvariant = miscData.logInvariant();
logTotalSupply = miscData.logTotalSupply();
oracleSampleCreationTimestamp = miscData.oracleSampleCreationTimestamp();
oracleIndex = miscData.oracleIndex();
oracleEnabled = miscData.oracleEnabled();
swapFeePercentage = miscData.swapFeePercentage();
}
function getSwapFeePercentage() public view returns (uint256) {
return _miscData.swapFeePercentage();
}
// Caller must be approved by the Vault's Authorizer
function setSwapFeePercentage(uint256 swapFeePercentage) external virtual authenticate whenNotPaused {
_setSwapFeePercentage(swapFeePercentage);
}
function _setSwapFeePercentage(uint256 swapFeePercentage) private {
_require(swapFeePercentage >= _MIN_SWAP_FEE_PERCENTAGE, Errors.MIN_SWAP_FEE_PERCENTAGE);
_require(swapFeePercentage <= _MAX_SWAP_FEE_PERCENTAGE, Errors.MAX_SWAP_FEE_PERCENTAGE);
_miscData = _miscData.setSwapFeePercentage(swapFeePercentage);
emit SwapFeePercentageChanged(swapFeePercentage);
}
/**
* @dev Balancer Governance can always enable the Oracle, even if it was originally not enabled. This allows for
* Pools that unexpectedly drive much more volume and liquidity than expected to serve as Price Oracles.
*
* Note that the Oracle can only be enabled - it can never be disabled.
*/
function enableOracle() external whenNotPaused authenticate {
_setOracleEnabled(true);
// Cache log invariant and supply only if the pool was initialized
if (totalSupply() > 0) {
_cacheInvariantAndSupply();
}
}
function _setOracleEnabled(bool enabled) internal {
_miscData = _miscData.setOracleEnabled(enabled);
emit OracleEnabledChanged(enabled);
}
// Caller must be approved by the Vault's Authorizer
function setPaused(bool paused) external authenticate {
_setPaused(paused);
}
function getNormalizedWeights() external view returns (uint256[] memory) {
return _normalizedWeights();
}
function _normalizedWeights() internal view virtual returns (uint256[] memory) {
uint256[] memory normalizedWeights = new uint256[](2);
normalizedWeights[0] = _normalizedWeights(true);
normalizedWeights[1] = _normalizedWeights(false);
return normalizedWeights;
}
function _normalizedWeights(bool token0) internal view virtual returns (uint256) {
return token0 ? _normalizedWeight0 : _normalizedWeight1;
}
function getLastInvariant() external view returns (uint256) {
return _lastInvariant;
}
/**
* @dev Returns the current value of the invariant.
*/
function getInvariant() public view returns (uint256) {
(, uint256[] memory balances, ) = getVault().getPoolTokens(getPoolId());
// Since the Pool hooks always work with upscaled balances, we manually
// upscale here for consistency
_upscaleArray(balances);
uint256[] memory normalizedWeights = _normalizedWeights();
return WeightedMath._calculateInvariant(normalizedWeights, balances);
}
// Swap Hooks
function onSwap(
SwapRequest memory request,
uint256 balanceTokenIn,
uint256 balanceTokenOut
) external virtual override whenNotPaused onlyVault(request.poolId) returns (uint256) {
bool tokenInIsToken0 = request.tokenIn == _token0;
uint256 scalingFactorTokenIn = _scalingFactor(tokenInIsToken0);
uint256 scalingFactorTokenOut = _scalingFactor(!tokenInIsToken0);
uint256 normalizedWeightIn = _normalizedWeights(tokenInIsToken0);
uint256 normalizedWeightOut = _normalizedWeights(!tokenInIsToken0);
// All token amounts are upscaled.
balanceTokenIn = _upscale(balanceTokenIn, scalingFactorTokenIn);
balanceTokenOut = _upscale(balanceTokenOut, scalingFactorTokenOut);
// Update price oracle with the pre-swap balances
_updateOracle(
request.lastChangeBlock,
tokenInIsToken0 ? balanceTokenIn : balanceTokenOut,
tokenInIsToken0 ? balanceTokenOut : balanceTokenIn
);
if (request.kind == IVault.SwapKind.GIVEN_IN) {
// Fees are subtracted before scaling, to reduce the complexity of the rounding direction analysis.
// This is amount - fee amount, so we round up (favoring a higher fee amount).
uint256 feeAmount = request.amount.mulUp(getSwapFeePercentage());
request.amount = _upscale(request.amount.sub(feeAmount), scalingFactorTokenIn);
uint256 amountOut = _onSwapGivenIn(
request,
balanceTokenIn,
balanceTokenOut,
normalizedWeightIn,
normalizedWeightOut
);
// amountOut tokens are exiting the Pool, so we round down.
return _downscaleDown(amountOut, scalingFactorTokenOut);
} else {
request.amount = _upscale(request.amount, scalingFactorTokenOut);
uint256 amountIn = _onSwapGivenOut(
request,
balanceTokenIn,
balanceTokenOut,
normalizedWeightIn,
normalizedWeightOut
);
// amountIn tokens are entering the Pool, so we round up.
amountIn = _downscaleUp(amountIn, scalingFactorTokenIn);
// Fees are added after scaling happens, to reduce the complexity of the rounding direction analysis.
// This is amount + fee amount, so we round up (favoring a higher fee amount).
return amountIn.divUp(getSwapFeePercentage().complement());
}
}
function _onSwapGivenIn(
SwapRequest memory swapRequest,
uint256 currentBalanceTokenIn,
uint256 currentBalanceTokenOut,
uint256 normalizedWeightIn,
uint256 normalizedWeightOut
) private pure returns (uint256) {
// Swaps are disabled while the contract is paused.
return
WeightedMath._calcOutGivenIn(
currentBalanceTokenIn,
normalizedWeightIn,
currentBalanceTokenOut,
normalizedWeightOut,
swapRequest.amount
);
}
function _onSwapGivenOut(
SwapRequest memory swapRequest,
uint256 currentBalanceTokenIn,
uint256 currentBalanceTokenOut,
uint256 normalizedWeightIn,
uint256 normalizedWeightOut
) private pure returns (uint256) {
// Swaps are disabled while the contract is paused.
return
WeightedMath._calcInGivenOut(
currentBalanceTokenIn,
normalizedWeightIn,
currentBalanceTokenOut,
normalizedWeightOut,
swapRequest.amount
);
}
// Join Hook
function onJoinPool(
bytes32 poolId,
address sender,
address recipient,
uint256[] memory balances,
uint256 lastChangeBlock,
uint256 protocolSwapFeePercentage,
bytes memory userData
)
external
virtual
override
onlyVault(poolId)
whenNotPaused
returns (uint256[] memory amountsIn, uint256[] memory dueProtocolFeeAmounts)
{
// All joins, including initializations, are disabled while the contract is paused.
uint256 bptAmountOut;
if (totalSupply() == 0) {
(bptAmountOut, amountsIn) = _onInitializePool(poolId, sender, recipient, userData);
// On initialization, we lock _MINIMUM_BPT by minting it for the zero address. This BPT acts as a minimum
// as it will never be burned, which reduces potential issues with rounding, and also prevents the Pool from
// ever being fully drained.
_require(bptAmountOut >= _MINIMUM_BPT, Errors.MINIMUM_BPT);
_mintPoolTokens(address(0), _MINIMUM_BPT);
_mintPoolTokens(recipient, bptAmountOut - _MINIMUM_BPT);
// amountsIn are amounts entering the Pool, so we round up.
_downscaleUpArray(amountsIn);
// There are no due protocol fee amounts during initialization
dueProtocolFeeAmounts = new uint256[](2);
} else {
_upscaleArray(balances);
// Update price oracle with the pre-join balances
_updateOracle(lastChangeBlock, balances[0], balances[1]);
(bptAmountOut, amountsIn, dueProtocolFeeAmounts) = _onJoinPool(
poolId,
sender,
recipient,
balances,
lastChangeBlock,
protocolSwapFeePercentage,
userData
);
// Note we no longer use `balances` after calling `_onJoinPool`, which may mutate it.
_mintPoolTokens(recipient, bptAmountOut);
// amountsIn are amounts entering the Pool, so we round up.
_downscaleUpArray(amountsIn);
// dueProtocolFeeAmounts are amounts exiting the Pool, so we round down.
_downscaleDownArray(dueProtocolFeeAmounts);
}
// Update cached total supply and invariant using the results after the join that will be used for future
// oracle updates.
_cacheInvariantAndSupply();
}
/**
* @dev Called when the Pool is joined for the first time; that is, when the BPT total supply is zero.
*
* Returns the amount of BPT to mint, and the token amounts the Pool will receive in return.
*
* Minted BPT will be sent to `recipient`, except for _MINIMUM_BPT, which will be deducted from this amount and sent
* to the zero address instead. This will cause that BPT to remain forever locked there, preventing total BTP from
* ever dropping below that value, and ensuring `_onInitializePool` can only be called once in the entire Pool's
* lifetime.
*
* The tokens granted to the Pool will be transferred from `sender`. These amounts are considered upscaled and will
* be downscaled (rounding up) before being returned to the Vault.
*/
function _onInitializePool(
bytes32,
address,
address,
bytes memory userData
) private returns (uint256, uint256[] memory) {
WeightedPool.JoinKind kind = userData.joinKind();
_require(kind == WeightedPool.JoinKind.INIT, Errors.UNINITIALIZED);
uint256[] memory amountsIn = userData.initialAmountsIn();
InputHelpers.ensureInputLengthMatch(amountsIn.length, 2);
_upscaleArray(amountsIn);
uint256[] memory normalizedWeights = _normalizedWeights();
uint256 invariantAfterJoin = WeightedMath._calculateInvariant(normalizedWeights, amountsIn);
// Set the initial BPT to the value of the invariant times the number of tokens. This makes BPT supply more
// consistent in Pools with similar compositions but different number of tokens.
uint256 bptAmountOut = Math.mul(invariantAfterJoin, 2);
_lastInvariant = invariantAfterJoin;
return (bptAmountOut, amountsIn);
}
/**
* @dev Called whenever the Pool is joined after the first initialization join (see `_onInitializePool`).
*
* Returns the amount of BPT to mint, the token amounts that the Pool will receive in return, and the number of
* tokens to pay in protocol swap fees.
*
* Implementations of this function might choose to mutate the `balances` array to save gas (e.g. when
* performing intermediate calculations, such as subtraction of due protocol fees). This can be done safely.
*
* Minted BPT will be sent to `recipient`.
*
* The tokens granted to the Pool will be transferred from `sender`. These amounts are considered upscaled and will
* be downscaled (rounding up) before being returned to the Vault.
*
* Due protocol swap fees will be taken from the Pool's balance in the Vault (see `IBasePool.onJoinPool`). These
* amounts are considered upscaled and will be downscaled (rounding down) before being returned to the Vault.
*/
function _onJoinPool(
bytes32,
address,
address,
uint256[] memory balances,
uint256,
uint256 protocolSwapFeePercentage,
bytes memory userData
)
private
returns (
uint256,
uint256[] memory,
uint256[] memory
)
{
uint256[] memory normalizedWeights = _normalizedWeights();
// Due protocol swap fee amounts are computed by measuring the growth of the invariant between the previous join
// or exit event and now - the invariant's growth is due exclusively to swap fees. This avoids spending gas
// computing them on each individual swap
uint256 invariantBeforeJoin = WeightedMath._calculateInvariant(normalizedWeights, balances);
uint256[] memory dueProtocolFeeAmounts = _getDueProtocolFeeAmounts(
balances,
normalizedWeights,
_lastInvariant,
invariantBeforeJoin,
protocolSwapFeePercentage
);
// Update current balances by subtracting the protocol fee amounts
_mutateAmounts(balances, dueProtocolFeeAmounts, FixedPoint.sub);
(uint256 bptAmountOut, uint256[] memory amountsIn) = _doJoin(balances, normalizedWeights, userData);
// Update the invariant with the balances the Pool will have after the join, in order to compute the
// protocol swap fee amounts due in future joins and exits.
_mutateAmounts(balances, amountsIn, FixedPoint.add);
_lastInvariant = WeightedMath._calculateInvariant(normalizedWeights, balances);
return (bptAmountOut, amountsIn, dueProtocolFeeAmounts);
}
function _doJoin(
uint256[] memory balances,
uint256[] memory normalizedWeights,
bytes memory userData
) private view returns (uint256, uint256[] memory) {
WeightedPool.JoinKind kind = userData.joinKind();
if (kind == WeightedPool.JoinKind.EXACT_TOKENS_IN_FOR_BPT_OUT) {
return _joinExactTokensInForBPTOut(balances, normalizedWeights, userData);
} else if (kind == WeightedPool.JoinKind.TOKEN_IN_FOR_EXACT_BPT_OUT) {
return _joinTokenInForExactBPTOut(balances, normalizedWeights, userData);
} else {
_revert(Errors.UNHANDLED_JOIN_KIND);
}
}
function _joinExactTokensInForBPTOut(
uint256[] memory balances,
uint256[] memory normalizedWeights,
bytes memory userData
) private view returns (uint256, uint256[] memory) {
(uint256[] memory amountsIn, uint256 minBPTAmountOut) = userData.exactTokensInForBptOut();
InputHelpers.ensureInputLengthMatch(amountsIn.length, 2);
_upscaleArray(amountsIn);
uint256 bptAmountOut = WeightedMath._calcBptOutGivenExactTokensIn(
balances,
normalizedWeights,
amountsIn,
totalSupply(),
getSwapFeePercentage()
);
_require(bptAmountOut >= minBPTAmountOut, Errors.BPT_OUT_MIN_AMOUNT);
return (bptAmountOut, amountsIn);
}
function _joinTokenInForExactBPTOut(
uint256[] memory balances,
uint256[] memory normalizedWeights,
bytes memory userData
) private view returns (uint256, uint256[] memory) {
(uint256 bptAmountOut, uint256 tokenIndex) = userData.tokenInForExactBptOut();
// Note that there is no maximum amountIn parameter: this is handled by `IVault.joinPool`.
_require(tokenIndex < 2, Errors.OUT_OF_BOUNDS);
uint256[] memory amountsIn = new uint256[](2);
amountsIn[tokenIndex] = WeightedMath._calcTokenInGivenExactBptOut(
balances[tokenIndex],
normalizedWeights[tokenIndex],
bptAmountOut,
totalSupply(),
getSwapFeePercentage()
);
return (bptAmountOut, amountsIn);
}
// Exit Hook
function onExitPool(
bytes32 poolId,
address sender,
address recipient,
uint256[] memory balances,
uint256 lastChangeBlock,
uint256 protocolSwapFeePercentage,
bytes memory userData
) external virtual override onlyVault(poolId) returns (uint256[] memory, uint256[] memory) {
_upscaleArray(balances);
(uint256 bptAmountIn, uint256[] memory amountsOut, uint256[] memory dueProtocolFeeAmounts) = _onExitPool(
poolId,
sender,
recipient,
balances,
lastChangeBlock,
protocolSwapFeePercentage,
userData
);
// Note we no longer use `balances` after calling `_onExitPool`, which may mutate it.
_burnPoolTokens(sender, bptAmountIn);
// Both amountsOut and dueProtocolFeeAmounts are amounts exiting the Pool, so we round down.
_downscaleDownArray(amountsOut);
_downscaleDownArray(dueProtocolFeeAmounts);
// Update cached total supply and invariant using the results after the exit that will be used for future
// oracle updates, only if the pool was not paused (to minimize code paths taken while paused).
if (_isNotPaused()) {
_cacheInvariantAndSupply();
}
return (amountsOut, dueProtocolFeeAmounts);
}
/**
* @dev Called whenever the Pool is exited.
*
* Returns the amount of BPT to burn, the token amounts for each Pool token that the Pool will grant in return, and
* the number of tokens to pay in protocol swap fees.
*
* Implementations of this function might choose to mutate the `balances` array to save gas (e.g. when
* performing intermediate calculations, such as subtraction of due protocol fees). This can be done safely.
*
* BPT will be burnt from `sender`.
*
* The Pool will grant tokens to `recipient`. These amounts are considered upscaled and will be downscaled
* (rounding down) before being returned to the Vault.
*
* Due protocol swap fees will be taken from the Pool's balance in the Vault (see `IBasePool.onExitPool`). These
* amounts are considered upscaled and will be downscaled (rounding down) before being returned to the Vault.
*/
function _onExitPool(
bytes32,
address,
address,
uint256[] memory balances,
uint256 lastChangeBlock,
uint256 protocolSwapFeePercentage,
bytes memory userData
)
private
returns (
uint256 bptAmountIn,
uint256[] memory amountsOut,
uint256[] memory dueProtocolFeeAmounts
)
{
// Exits are not completely disabled while the contract is paused: proportional exits (exact BPT in for tokens
// out) remain functional.
uint256[] memory normalizedWeights = _normalizedWeights();
if (_isNotPaused()) {
// Update price oracle with the pre-exit balances
_updateOracle(lastChangeBlock, balances[0], balances[1]);
// Due protocol swap fee amounts are computed by measuring the growth of the invariant between the previous
// join or exit event and now - the invariant's growth is due exclusively to swap fees. This avoids
// spending gas calculating the fees on each individual swap.
uint256 invariantBeforeExit = WeightedMath._calculateInvariant(normalizedWeights, balances);
dueProtocolFeeAmounts = _getDueProtocolFeeAmounts(
balances,
normalizedWeights,
_lastInvariant,
invariantBeforeExit,
protocolSwapFeePercentage
);
// Update current balances by subtracting the protocol fee amounts
_mutateAmounts(balances, dueProtocolFeeAmounts, FixedPoint.sub);
} else {
// If the contract is paused, swap protocol fee amounts are not charged and the oracle is not updated
// to avoid extra calculations and reduce the potential for errors.
dueProtocolFeeAmounts = new uint256[](2);
}
(bptAmountIn, amountsOut) = _doExit(balances, normalizedWeights, userData);
// Update the invariant with the balances the Pool will have after the exit, in order to compute the
// protocol swap fees due in future joins and exits.
_mutateAmounts(balances, amountsOut, FixedPoint.sub);
_lastInvariant = WeightedMath._calculateInvariant(normalizedWeights, balances);
return (bptAmountIn, amountsOut, dueProtocolFeeAmounts);
}
function _doExit(
uint256[] memory balances,
uint256[] memory normalizedWeights,
bytes memory userData
) private view returns (uint256, uint256[] memory) {
WeightedPool.ExitKind kind = userData.exitKind();
if (kind == WeightedPool.ExitKind.EXACT_BPT_IN_FOR_ONE_TOKEN_OUT) {
return _exitExactBPTInForTokenOut(balances, normalizedWeights, userData);
} else if (kind == WeightedPool.ExitKind.EXACT_BPT_IN_FOR_TOKENS_OUT) {
return _exitExactBPTInForTokensOut(balances, userData);
} else {
// ExitKind.BPT_IN_FOR_EXACT_TOKENS_OUT
return _exitBPTInForExactTokensOut(balances, normalizedWeights, userData);
}
}
function _exitExactBPTInForTokenOut(
uint256[] memory balances,
uint256[] memory normalizedWeights,
bytes memory userData
) private view whenNotPaused returns (uint256, uint256[] memory) {
// This exit function is disabled if the contract is paused.
(uint256 bptAmountIn, uint256 tokenIndex) = userData.exactBptInForTokenOut();
// Note that there is no minimum amountOut parameter: this is handled by `IVault.exitPool`.
_require(tokenIndex < 2, Errors.OUT_OF_BOUNDS);
// We exit in a single token, so we initialize amountsOut with zeros
uint256[] memory amountsOut = new uint256[](2);
// And then assign the result to the selected token
amountsOut[tokenIndex] = WeightedMath._calcTokenOutGivenExactBptIn(
balances[tokenIndex],
normalizedWeights[tokenIndex],
bptAmountIn,
totalSupply(),
getSwapFeePercentage()
);
return (bptAmountIn, amountsOut);
}
function _exitExactBPTInForTokensOut(uint256[] memory balances, bytes memory userData)
private
view
returns (uint256, uint256[] memory)
{
// This exit function is the only one that is not disabled if the contract is paused: it remains unrestricted
// in an attempt to provide users with a mechanism to retrieve their tokens in case of an emergency.
// This particular exit function is the only one that remains available because it is the simplest one, and
// therefore the one with the lowest likelihood of errors.
uint256 bptAmountIn = userData.exactBptInForTokensOut();
// Note that there is no minimum amountOut parameter: this is handled by `IVault.exitPool`.
uint256[] memory amountsOut = WeightedMath._calcTokensOutGivenExactBptIn(balances, bptAmountIn, totalSupply());
return (bptAmountIn, amountsOut);
}
function _exitBPTInForExactTokensOut(
uint256[] memory balances,
uint256[] memory normalizedWeights,
bytes memory userData
) private view whenNotPaused returns (uint256, uint256[] memory) {
// This exit function is disabled if the contract is paused.
(uint256[] memory amountsOut, uint256 maxBPTAmountIn) = userData.bptInForExactTokensOut();
InputHelpers.ensureInputLengthMatch(amountsOut.length, 2);
_upscaleArray(amountsOut);
uint256 bptAmountIn = WeightedMath._calcBptInGivenExactTokensOut(
balances,
normalizedWeights,
amountsOut,
totalSupply(),
getSwapFeePercentage()
);
_require(bptAmountIn <= maxBPTAmountIn, Errors.BPT_IN_MAX_AMOUNT);
return (bptAmountIn, amountsOut);
}
// Oracle functions
function getLargestSafeQueryWindow() external pure override returns (uint256) {
return 34 hours;
}
function getLatest(Variable variable) external view override returns (uint256) {
int256 instantValue = _getInstantValue(variable, _miscData.oracleIndex());
return _fromLowResLog(instantValue);
}
function getTimeWeightedAverage(OracleAverageQuery[] memory queries)
external
view
override
returns (uint256[] memory results)
{
results = new uint256[](queries.length);
uint256 oracleIndex = _miscData.oracleIndex();
OracleAverageQuery memory query;
for (uint256 i = 0; i < queries.length; ++i) {
query = queries[i];
_require(query.secs != 0, Errors.ORACLE_BAD_SECS);
int256 beginAccumulator = _getPastAccumulator(query.variable, oracleIndex, query.ago + query.secs);
int256 endAccumulator = _getPastAccumulator(query.variable, oracleIndex, query.ago);
results[i] = _fromLowResLog((endAccumulator - beginAccumulator) / int256(query.secs));
}
}
function getPastAccumulators(OracleAccumulatorQuery[] memory queries)
external
view
override
returns (int256[] memory results)
{
results = new int256[](queries.length);
uint256 oracleIndex = _miscData.oracleIndex();
OracleAccumulatorQuery memory query;
for (uint256 i = 0; i < queries.length; ++i) {
query = queries[i];
results[i] = _getPastAccumulator(query.variable, oracleIndex, query.ago);
}
}
/**
* @dev Updates the Price Oracle based on the Pool's current state (balances, BPT supply and invariant). Must be
* called on *all* state-changing functions with the balances *before* the state change happens, and with
* `lastChangeBlock` as the number of the block in which any of the balances last changed.
*/
function _updateOracle(
uint256 lastChangeBlock,
uint256 balanceToken0,
uint256 balanceToken1
) internal {
bytes32 miscData = _miscData;
if (miscData.oracleEnabled() && block.number > lastChangeBlock) {
int256 logSpotPrice = WeightedOracleMath._calcLogSpotPrice(
_normalizedWeight0,
balanceToken0,
_normalizedWeight1,
balanceToken1
);
int256 logBPTPrice = WeightedOracleMath._calcLogBPTPrice(
_normalizedWeight0,
balanceToken0,
miscData.logTotalSupply()
);
uint256 oracleCurrentIndex = miscData.oracleIndex();
uint256 oracleCurrentSampleInitialTimestamp = miscData.oracleSampleCreationTimestamp();
uint256 oracleUpdatedIndex = _processPriceData(
oracleCurrentSampleInitialTimestamp,
oracleCurrentIndex,
logSpotPrice,
logBPTPrice,
miscData.logInvariant()
);
if (oracleCurrentIndex != oracleUpdatedIndex) {
// solhint-disable not-rely-on-time
miscData = miscData.setOracleIndex(oracleUpdatedIndex);
miscData = miscData.setOracleSampleCreationTimestamp(block.timestamp);
_miscData = miscData;
}
}
}
/**
* @dev Stores the logarithm of the invariant and BPT total supply, to be later used in each oracle update. Because
* it is stored in miscData, which is read in all operations (including swaps), this saves gas by not requiring to
* compute or read these values when updating the oracle.
*
* This function must be called by all actions that update the invariant and BPT supply (joins and exits). Swaps
* also alter the invariant due to collected swap fees, but this growth is considered negligible and not accounted
* for.
*/
function _cacheInvariantAndSupply() internal {
bytes32 miscData = _miscData;
if (miscData.oracleEnabled()) {
miscData = miscData.setLogInvariant(WeightedOracleMath._toLowResLog(_lastInvariant));
miscData = miscData.setLogTotalSupply(WeightedOracleMath._toLowResLog(totalSupply()));
_miscData = miscData;
}
}
// Query functions
/**
* @dev Returns the amount of BPT that would be granted to `recipient` if the `onJoinPool` hook were called by the
* Vault with the same arguments, along with the number of tokens `sender` would have to supply.
*
* This function is not meant to be called directly, but rather from a helper contract that fetches current Vault
* data, such as the protocol swap fee percentage and Pool balances.
*
* Like `IVault.queryBatchSwap`, this function is not view due to internal implementation details: the caller must
* explicitly use eth_call instead of eth_sendTransaction.
*/
function queryJoin(
bytes32 poolId,
address sender,
address recipient,
uint256[] memory balances,
uint256 lastChangeBlock,
uint256 protocolSwapFeePercentage,
bytes memory userData
) external returns (uint256 bptOut, uint256[] memory amountsIn) {
InputHelpers.ensureInputLengthMatch(balances.length, 2);
_queryAction(
poolId,
sender,
recipient,
balances,
lastChangeBlock,
protocolSwapFeePercentage,
userData,
_onJoinPool,
_downscaleUpArray
);
// The `return` opcode is executed directly inside `_queryAction`, so execution never reaches this statement,
// and we don't need to return anything here - it just silences compiler warnings.
return (bptOut, amountsIn);
}
/**
* @dev Returns the amount of BPT that would be burned from `sender` if the `onExitPool` hook were called by the
* Vault with the same arguments, along with the number of tokens `recipient` would receive.
*
* This function is not meant to be called directly, but rather from a helper contract that fetches current Vault
* data, such as the protocol swap fee percentage and Pool balances.
*
* Like `IVault.queryBatchSwap`, this function is not view due to internal implementation details: the caller must
* explicitly use eth_call instead of eth_sendTransaction.
*/
function queryExit(
bytes32 poolId,
address sender,
address recipient,
uint256[] memory balances,
uint256 lastChangeBlock,
uint256 protocolSwapFeePercentage,
bytes memory userData
) external returns (uint256 bptIn, uint256[] memory amountsOut) {
InputHelpers.ensureInputLengthMatch(balances.length, 2);
_queryAction(
poolId,
sender,
recipient,
balances,
lastChangeBlock,
protocolSwapFeePercentage,
userData,
_onExitPool,
_downscaleDownArray
);
// The `return` opcode is executed directly inside `_queryAction`, so execution never reaches this statement,
// and we don't need to return anything here - it just silences compiler warnings.
return (bptIn, amountsOut);
}
// Helpers
function _getDueProtocolFeeAmounts(
uint256[] memory balances,
uint256[] memory normalizedWeights,
uint256 previousInvariant,
uint256 currentInvariant,
uint256 protocolSwapFeePercentage
) private view returns (uint256[] memory) {
// Initialize with zeros
uint256[] memory dueProtocolFeeAmounts = new uint256[](2);
// Early return if the protocol swap fee percentage is zero, saving gas.
if (protocolSwapFeePercentage == 0) {
return dueProtocolFeeAmounts;
}
// The protocol swap fees are always paid using the token with the largest weight in the Pool. As this is the
// token that is expected to have the largest balance, using it to pay fees should not unbalance the Pool.
dueProtocolFeeAmounts[_maxWeightTokenIndex] = WeightedMath._calcDueTokenProtocolSwapFeeAmount(
balances[_maxWeightTokenIndex],
normalizedWeights[_maxWeightTokenIndex],
previousInvariant,
currentInvariant,
protocolSwapFeePercentage
);
return dueProtocolFeeAmounts;
}
/**
* @dev Mutates `amounts` by applying `mutation` with each entry in `arguments`.
*
* Equivalent to `amounts = amounts.map(mutation)`.
*/
function _mutateAmounts(
uint256[] memory toMutate,
uint256[] memory arguments,
function(uint256, uint256) pure returns (uint256) mutation
) private pure {
toMutate[0] = mutation(toMutate[0], arguments[0]);
toMutate[1] = mutation(toMutate[1], arguments[1]);
}
/**
* @dev This function returns the appreciation of one BPT relative to the
* underlying tokens. This starts at 1 when the pool is created and grows over time
*/
function getRate() public view returns (uint256) {
// The initial BPT supply is equal to the invariant times the number of tokens.
return Math.mul(getInvariant(), 2).divDown(totalSupply());
}
// Scaling
/**
* @dev Returns a scaling factor that, when multiplied to a token amount for `token`, normalizes its balance as if
* it had 18 decimals.
*/
function _computeScalingFactor(IERC20 token) private view returns (uint256) {
// Tokens that don't implement the `decimals` method are not supported.
uint256 tokenDecimals = ERC20(address(token)).decimals();
// Tokens with more than 18 decimals are not supported.
uint256 decimalsDifference = Math.sub(18, tokenDecimals);
return 10**decimalsDifference;
}
/**
* @dev Returns the scaling factor for one of the Pool's tokens. Reverts if `token` is not a token registered by the
* Pool.
*/
function _scalingFactor(bool token0) internal view returns (uint256) {
return token0 ? _scalingFactor0 : _scalingFactor1;
}
/**
* @dev Applies `scalingFactor` to `amount`, resulting in a larger or equal value depending on whether it needed
* scaling or not.
*/
function _upscale(uint256 amount, uint256 scalingFactor) internal pure returns (uint256) {
return Math.mul(amount, scalingFactor);
}
/**
* @dev Same as `_upscale`, but for an entire array (of two elements). This function does not return anything, but
* instead *mutates* the `amounts` array.
*/
function _upscaleArray(uint256[] memory amounts) internal view {
amounts[0] = Math.mul(amounts[0], _scalingFactor(true));
amounts[1] = Math.mul(amounts[1], _scalingFactor(false));
}
/**
* @dev Reverses the `scalingFactor` applied to `amount`, resulting in a smaller or equal value depending on
* whether it needed scaling or not. The result is rounded down.
*/
function _downscaleDown(uint256 amount, uint256 scalingFactor) internal pure returns (uint256) {
return Math.divDown(amount, scalingFactor);
}
/**
* @dev Same as `_downscaleDown`, but for an entire array (of two elements). This function does not return anything,
* but instead *mutates* the `amounts` array.
*/
function _downscaleDownArray(uint256[] memory amounts) internal view {
amounts[0] = Math.divDown(amounts[0], _scalingFactor(true));
amounts[1] = Math.divDown(amounts[1], _scalingFactor(false));
}
/**
* @dev Reverses the `scalingFactor` applied to `amount`, resulting in a smaller or equal value depending on
* whether it needed scaling or not. The result is rounded up.
*/
function _downscaleUp(uint256 amount, uint256 scalingFactor) internal pure returns (uint256) {
return Math.divUp(amount, scalingFactor);
}
/**
* @dev Same as `_downscaleUp`, but for an entire array (of two elements). This function does not return anything,
* but instead *mutates* the `amounts` array.
*/
function _downscaleUpArray(uint256[] memory amounts) internal view {
amounts[0] = Math.divUp(amounts[0], _scalingFactor(true));
amounts[1] = Math.divUp(amounts[1], _scalingFactor(false));
}
function _getAuthorizer() internal view override returns (IAuthorizer) {
// Access control management is delegated to the Vault's Authorizer. This lets Balancer Governance manage which
// accounts can call permissioned functions: for example, to perform emergency pauses.
// If the owner is delegated, then *all* permissioned functions, including `setSwapFeePercentage`, will be under
// Governance control.
return getVault().getAuthorizer();
}
function _queryAction(
bytes32 poolId,
address sender,
address recipient,
uint256[] memory balances,
uint256 lastChangeBlock,
uint256 protocolSwapFeePercentage,
bytes memory userData,
function(bytes32, address, address, uint256[] memory, uint256, uint256, bytes memory)
internal
returns (uint256, uint256[] memory, uint256[] memory) _action,
function(uint256[] memory) internal view _downscaleArray
) private {
// This uses the same technique used by the Vault in queryBatchSwap. Refer to that function for a detailed
// explanation.
if (msg.sender != address(this)) {
// We perform an external call to ourselves, forwarding the same calldata. In this call, the else clause of
// the preceding if statement will be executed instead.
// solhint-disable-next-line avoid-low-level-calls
(bool success, ) = address(this).call(msg.data);
// solhint-disable-next-line no-inline-assembly
assembly {
// This call should always revert to decode the bpt and token amounts from the revert reason
switch success
case 0 {
// Note we are manually writing the memory slot 0. We can safely overwrite whatever is
// stored there as we take full control of the execution and then immediately return.
// We copy the first 4 bytes to check if it matches with the expected signature, otherwise
// there was another revert reason and we should forward it.
returndatacopy(0, 0, 0x04)
let error := and(mload(0), 0xffffffff00000000000000000000000000000000000000000000000000000000)
// If the first 4 bytes don't match with the expected signature, we forward the revert reason.
if eq(eq(error, 0x43adbafb00000000000000000000000000000000000000000000000000000000), 0) {
returndatacopy(0, 0, returndatasize())
revert(0, returndatasize())
}
// The returndata contains the signature, followed by the raw memory representation of the
// `bptAmount` and `tokenAmounts` (array: length + data). We need to return an ABI-encoded
// representation of these.
// An ABI-encoded response will include one additional field to indicate the starting offset of
// the `tokenAmounts` array. The `bptAmount` will be laid out in the first word of the
// returndata.
//
// In returndata:
// [ signature ][ bptAmount ][ tokenAmounts length ][ tokenAmounts values ]
// [ 4 bytes ][ 32 bytes ][ 32 bytes ][ (32 * length) bytes ]
//
// We now need to return (ABI-encoded values):
// [ bptAmount ][ tokeAmounts offset ][ tokenAmounts length ][ tokenAmounts values ]
// [ 32 bytes ][ 32 bytes ][ 32 bytes ][ (32 * length) bytes ]
// We copy 32 bytes for the `bptAmount` from returndata into memory.
// Note that we skip the first 4 bytes for the error signature
returndatacopy(0, 0x04, 32)
// The offsets are 32-bytes long, so the array of `tokenAmounts` will start after
// the initial 64 bytes.
mstore(0x20, 64)
// We now copy the raw memory array for the `tokenAmounts` from returndata into memory.
// Since bpt amount and offset take up 64 bytes, we start copying at address 0x40. We also
// skip the first 36 bytes from returndata, which correspond to the signature plus bpt amount.
returndatacopy(0x40, 0x24, sub(returndatasize(), 36))
// We finally return the ABI-encoded uint256 and the array, which has a total length equal to
// the size of returndata, plus the 32 bytes of the offset but without the 4 bytes of the
// error signature.
return(0, add(returndatasize(), 28))
}
default {
// This call should always revert, but we fail nonetheless if that didn't happen
invalid()
}
}
} else {
_upscaleArray(balances);
(uint256 bptAmount, uint256[] memory tokenAmounts, ) = _action(
poolId,
sender,
recipient,
balances,
lastChangeBlock,
protocolSwapFeePercentage,
userData
);
_downscaleArray(tokenAmounts);
// solhint-disable-next-line no-inline-assembly
assembly {
// We will return a raw representation of `bptAmount` and `tokenAmounts` in memory, which is composed of
// a 32-byte uint256, followed by a 32-byte for the array length, and finally the 32-byte uint256 values
// Because revert expects a size in bytes, we multiply the array length (stored at `tokenAmounts`) by 32
let size := mul(mload(tokenAmounts), 32)
// We store the `bptAmount` in the previous slot to the `tokenAmounts` array. We can make sure there
// will be at least one available slot due to how the memory scratch space works.
// We can safely overwrite whatever is stored in this slot as we will revert immediately after that.
let start := sub(tokenAmounts, 0x20)
mstore(start, bptAmount)
// We send one extra value for the error signature "QueryError(uint256,uint256[])" which is 0x43adbafb
// We use the previous slot to `bptAmount`.
mstore(sub(start, 0x20), 0x0000000000000000000000000000000000000000000000000000000043adbafb)
start := sub(start, 0x04)
// When copying from `tokenAmounts` into returndata, we copy the additional 68 bytes to also return
// the `bptAmount`, the array length, and the error signature.
revert(start, add(size, 68))
}
}
}
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
pragma experimental ABIEncoderV2;
import "../../lib/helpers/WordCodec.sol";
/**
* @dev This module provides an interface to store seemingly unrelated pieces of information, in particular used by
* Weighted Pools of 2 tokens with a price oracle.
*
* These pieces of information are all kept together in a single storage slot to reduce the number of storage reads. In
* particular, we not only store configuration values (such as the swap fee percentage), but also cache
* reduced-precision versions of the total BPT supply and invariant, which lets us not access nor compute these values
* when producing oracle updates during a swap.
*
* Data is stored with the following structure:
*
* [ swap fee pct | oracle enabled | oracle index | oracle sample initial timestamp | log supply | log invariant ]
* [ uint64 | bool | uint10 | uint31 | int22 | int22 ]
*
* Note that we are not using the most-significant 106 bits.
*/
library WeightedPool2TokensMiscData {
using WordCodec for bytes32;
using WordCodec for uint256;
uint256 private constant _LOG_INVARIANT_OFFSET = 0;
uint256 private constant _LOG_TOTAL_SUPPLY_OFFSET = 22;
uint256 private constant _ORACLE_SAMPLE_CREATION_TIMESTAMP_OFFSET = 44;
uint256 private constant _ORACLE_INDEX_OFFSET = 75;
uint256 private constant _ORACLE_ENABLED_OFFSET = 85;
uint256 private constant _SWAP_FEE_PERCENTAGE_OFFSET = 86;
/**
* @dev Returns the cached logarithm of the invariant.
*/
function logInvariant(bytes32 data) internal pure returns (int256) {
return data.decodeInt22(_LOG_INVARIANT_OFFSET);
}
/**
* @dev Returns the cached logarithm of the total supply.
*/
function logTotalSupply(bytes32 data) internal pure returns (int256) {
return data.decodeInt22(_LOG_TOTAL_SUPPLY_OFFSET);
}
/**
* @dev Returns the timestamp of the creation of the oracle's latest sample.
*/
function oracleSampleCreationTimestamp(bytes32 data) internal pure returns (uint256) {
return data.decodeUint31(_ORACLE_SAMPLE_CREATION_TIMESTAMP_OFFSET);
}
/**
* @dev Returns the index of the oracle's latest sample.
*/
function oracleIndex(bytes32 data) internal pure returns (uint256) {
return data.decodeUint10(_ORACLE_INDEX_OFFSET);
}
/**
* @dev Returns true if the oracle is enabled.
*/
function oracleEnabled(bytes32 data) internal pure returns (bool) {
return data.decodeBool(_ORACLE_ENABLED_OFFSET);
}
/**
* @dev Returns the swap fee percentage.
*/
function swapFeePercentage(bytes32 data) internal pure returns (uint256) {
return data.decodeUint64(_SWAP_FEE_PERCENTAGE_OFFSET);
}
/**
* @dev Sets the logarithm of the invariant in `data`, returning the updated value.
*/
function setLogInvariant(bytes32 data, int256 _logInvariant) internal pure returns (bytes32) {
return data.insertInt22(_logInvariant, _LOG_INVARIANT_OFFSET);
}
/**
* @dev Sets the logarithm of the total supply in `data`, returning the updated value.
*/
function setLogTotalSupply(bytes32 data, int256 _logTotalSupply) internal pure returns (bytes32) {
return data.insertInt22(_logTotalSupply, _LOG_TOTAL_SUPPLY_OFFSET);
}
/**
* @dev Sets the timestamp of the creation of the oracle's latest sample in `data`, returning the updated value.
*/
function setOracleSampleCreationTimestamp(bytes32 data, uint256 _initialTimestamp) internal pure returns (bytes32) {
return data.insertUint31(_initialTimestamp, _ORACLE_SAMPLE_CREATION_TIMESTAMP_OFFSET);
}
/**
* @dev Sets the index of the oracle's latest sample in `data`, returning the updated value.
*/
function setOracleIndex(bytes32 data, uint256 _oracleIndex) internal pure returns (bytes32) {
return data.insertUint10(_oracleIndex, _ORACLE_INDEX_OFFSET);
}
/**
* @dev Enables or disables the oracle in `data`, returning the updated value.
*/
function setOracleEnabled(bytes32 data, bool _oracleEnabled) internal pure returns (bytes32) {
return data.insertBoolean(_oracleEnabled, _ORACLE_ENABLED_OFFSET);
}
/**
* @dev Sets the swap fee percentage in `data`, returning the updated value.
*/
function setSwapFeePercentage(bytes32 data, uint256 _swapFeePercentage) internal pure returns (bytes32) {
return data.insertUint64(_swapFeePercentage, _SWAP_FEE_PERCENTAGE_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 "../../lib/openzeppelin/IERC20.sol";
import "./WeightedPool.sol";
library WeightedPoolUserDataHelpers {
function joinKind(bytes memory self) internal pure returns (WeightedPool.JoinKind) {
return abi.decode(self, (WeightedPool.JoinKind));
}
function exitKind(bytes memory self) internal pure returns (WeightedPool.ExitKind) {
return abi.decode(self, (WeightedPool.ExitKind));
}
// Joins
function initialAmountsIn(bytes memory self) internal pure returns (uint256[] memory amountsIn) {
(, amountsIn) = abi.decode(self, (WeightedPool.JoinKind, uint256[]));
}
function exactTokensInForBptOut(bytes memory self)
internal
pure
returns (uint256[] memory amountsIn, uint256 minBPTAmountOut)
{
(, amountsIn, minBPTAmountOut) = abi.decode(self, (WeightedPool.JoinKind, uint256[], uint256));
}
function tokenInForExactBptOut(bytes memory self) internal pure returns (uint256 bptAmountOut, uint256 tokenIndex) {
(, bptAmountOut, tokenIndex) = abi.decode(self, (WeightedPool.JoinKind, uint256, uint256));
}
// Exits
function exactBptInForTokenOut(bytes memory self) internal pure returns (uint256 bptAmountIn, uint256 tokenIndex) {
(, bptAmountIn, tokenIndex) = abi.decode(self, (WeightedPool.ExitKind, uint256, uint256));
}
function exactBptInForTokensOut(bytes memory self) internal pure returns (uint256 bptAmountIn) {
(, bptAmountIn) = abi.decode(self, (WeightedPool.ExitKind, uint256));
}
function bptInForExactTokensOut(bytes memory self)
internal
pure
returns (uint256[] memory amountsOut, uint256 maxBPTAmountIn)
{
(, amountsOut, maxBPTAmountIn) = abi.decode(self, (WeightedPool.ExitKind, uint256[], uint256));
}
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
/**
* @dev Library for encoding and decoding values stored inside a 256 bit word. Typically used to pack multiple values in
* a single storage slot, saving gas by performing less storage accesses.
*
* Each value is defined by its size and the least significant bit in the word, also known as offset. For example, two
* 128 bit values may be encoded in a word by assigning one an offset of 0, and the other an offset of 128.
*/
library WordCodec {
// Masks are values with the least significant N bits set. They can be used to extract an encoded value from a word,
// or to insert a new one replacing the old.
uint256 private constant _MASK_1 = 2**(1) - 1;
uint256 private constant _MASK_10 = 2**(10) - 1;
uint256 private constant _MASK_22 = 2**(22) - 1;
uint256 private constant _MASK_31 = 2**(31) - 1;
uint256 private constant _MASK_53 = 2**(53) - 1;
uint256 private constant _MASK_64 = 2**(64) - 1;
// Largest positive values that can be represented as N bits signed integers.
int256 private constant _MAX_INT_22 = 2**(21) - 1;
int256 private constant _MAX_INT_53 = 2**(52) - 1;
// In-place insertion
/**
* @dev Inserts a boolean value shifted by an offset into a 256 bit word, replacing the old value. Returns the new
* word.
*/
function insertBoolean(
bytes32 word,
bool value,
uint256 offset
) internal pure returns (bytes32) {
bytes32 clearedWord = bytes32(uint256(word) & ~(_MASK_1 << offset));
return clearedWord | bytes32(uint256(value ? 1 : 0) << offset);
}
// Unsigned
/**
* @dev Inserts a 10 bit unsigned integer shifted by an offset into a 256 bit word, replacing the old value. Returns
* the new word.
*
* Assumes `value` can be represented using 10 bits.
*/
function insertUint10(
bytes32 word,
uint256 value,
uint256 offset
) internal pure returns (bytes32) {
bytes32 clearedWord = bytes32(uint256(word) & ~(_MASK_10 << offset));
return clearedWord | bytes32(value << offset);
}
/**
* @dev Inserts a 31 bit unsigned integer shifted by an offset into a 256 bit word, replacing the old value. Returns
* the new word.
*
* Assumes `value` can be represented using 31 bits.
*/
function insertUint31(
bytes32 word,
uint256 value,
uint256 offset
) internal pure returns (bytes32) {
bytes32 clearedWord = bytes32(uint256(word) & ~(_MASK_31 << offset));
return clearedWord | bytes32(value << offset);
}
/**
* @dev Inserts a 64 bit unsigned integer shifted by an offset into a 256 bit word, replacing the old value. Returns
* the new word.
*
* Assumes `value` can be represented using 64 bits.
*/
function insertUint64(
bytes32 word,
uint256 value,
uint256 offset
) internal pure returns (bytes32) {
bytes32 clearedWord = bytes32(uint256(word) & ~(_MASK_64 << offset));
return clearedWord | bytes32(value << offset);
}
// Signed
/**
* @dev Inserts a 22 bits signed integer shifted by an offset into a 256 bit word, replacing the old value. Returns
* the new word.
*
* Assumes `value` can be represented using 22 bits.
*/
function insertInt22(
bytes32 word,
int256 value,
uint256 offset
) internal pure returns (bytes32) {
bytes32 clearedWord = bytes32(uint256(word) & ~(_MASK_22 << offset));
// Integer values need masking to remove the upper bits of negative values.
return clearedWord | bytes32((uint256(value) & _MASK_22) << offset);
}
// Encoding
// Unsigned
/**
* @dev Encodes a 31 bit unsigned integer shifted by an offset.
*
* The return value can be logically ORed with other encoded values to form a 256 bit word.
*/
function encodeUint31(uint256 value, uint256 offset) internal pure returns (bytes32) {
return bytes32(value << offset);
}
// Signed
/**
* @dev Encodes a 22 bits signed integer shifted by an offset.
*
* The return value can be logically ORed with other encoded values to form a 256 bit word.
*/
function encodeInt22(int256 value, uint256 offset) internal pure returns (bytes32) {
// Integer values need masking to remove the upper bits of negative values.
return bytes32((uint256(value) & _MASK_22) << offset);
}
/**
* @dev Encodes a 53 bits signed integer shifted by an offset.
*
* The return value can be logically ORed with other encoded values to form a 256 bit word.
*/
function encodeInt53(int256 value, uint256 offset) internal pure returns (bytes32) {
// Integer values need masking to remove the upper bits of negative values.
return bytes32((uint256(value) & _MASK_53) << offset);
}
// Decoding
/**
* @dev Decodes and returns a boolean shifted by an offset from a 256 bit word.
*/
function decodeBool(bytes32 word, uint256 offset) internal pure returns (bool) {
return (uint256(word >> offset) & _MASK_1) == 1;
}
// Unsigned
/**
* @dev Decodes and returns a 10 bit unsigned integer shifted by an offset from a 256 bit word.
*/
function decodeUint10(bytes32 word, uint256 offset) internal pure returns (uint256) {
return uint256(word >> offset) & _MASK_10;
}
/**
* @dev Decodes and returns a 31 bit unsigned integer shifted by an offset from a 256 bit word.
*/
function decodeUint31(bytes32 word, uint256 offset) internal pure returns (uint256) {
return uint256(word >> offset) & _MASK_31;
}
/**
* @dev Decodes and returns a 64 bit unsigned integer shifted by an offset from a 256 bit word.
*/
function decodeUint64(bytes32 word, uint256 offset) internal pure returns (uint256) {
return uint256(word >> offset) & _MASK_64;
}
// Signed
/**
* @dev Decodes and returns a 22 bits signed integer shifted by an offset from a 256 bit word.
*/
function decodeInt22(bytes32 word, uint256 offset) internal pure returns (int256) {
int256 value = int256(uint256(word >> offset) & _MASK_22);
// In case the decoded value is greater than the max positive integer that can be represented with 22 bits,
// we know it was originally a negative integer. Therefore, we mask it to restore the sign in the 256 bit
// representation.
return value > _MAX_INT_22 ? (value | int256(~_MASK_22)) : value;
}
/**
* @dev Decodes and returns a 53 bits signed integer shifted by an offset from a 256 bit word.
*/
function decodeInt53(bytes32 word, uint256 offset) internal pure returns (int256) {
int256 value = int256(uint256(word >> offset) & _MASK_53);
// In case the decoded value is greater than the max positive integer that can be represented with 53 bits,
// we know it was originally a negative integer. Therefore, we mask it to restore the sign in the 256 bit
// representation.
return value > _MAX_INT_53 ? (value | int256(~_MASK_53)) : value;
}
}
{
"compilationTarget": {
"contracts/pools/weighted/WeightedPool2Tokens.sol": "WeightedPool2Tokens"
},
"evmVersion": "istanbul",
"libraries": {},
"metadata": {
"bytecodeHash": "ipfs"
},
"optimizer": {
"enabled": true,
"runs": 200
},
"remappings": []
}[{"inputs":[{"components":[{"internalType":"contract IVault","name":"vault","type":"address"},{"internalType":"string","name":"name","type":"string"},{"internalType":"string","name":"symbol","type":"string"},{"internalType":"contract IERC20","name":"token0","type":"address"},{"internalType":"contract IERC20","name":"token1","type":"address"},{"internalType":"uint256","name":"normalizedWeight0","type":"uint256"},{"internalType":"uint256","name":"normalizedWeight1","type":"uint256"},{"internalType":"uint256","name":"swapFeePercentage","type":"uint256"},{"internalType":"uint256","name":"pauseWindowDuration","type":"uint256"},{"internalType":"uint256","name":"bufferPeriodDuration","type":"uint256"},{"internalType":"bool","name":"oracleEnabled","type":"bool"},{"internalType":"address","name":"owner","type":"address"}],"internalType":"struct WeightedPool2Tokens.NewPoolParams","name":"params","type":"tuple"}],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"owner","type":"address"},{"indexed":true,"internalType":"address","name":"spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"internalType":"bool","name":"enabled","type":"bool"}],"name":"OracleEnabledChanged","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"internalType":"bool","name":"paused","type":"bool"}],"name":"PausedStateChanged","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"internalType":"uint256","name":"swapFeePercentage","type":"uint256"}],"name":"SwapFeePercentageChanged","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"from","type":"address"},{"indexed":true,"internalType":"address","name":"to","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Transfer","type":"event"},{"inputs":[],"name":"DOMAIN_SEPARATOR","outputs":[{"internalType":"bytes32","name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"owner","type":"address"},{"internalType":"address","name":"spender","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"stateMutability":"pure","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"decreaseApproval","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"enableOracle","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"bytes4","name":"selector","type":"bytes4"}],"name":"getActionId","outputs":[{"internalType":"bytes32","name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"getAuthorizer","outputs":[{"internalType":"contract IAuthorizer","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"getInvariant","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"getLargestSafeQueryWindow","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"pure","type":"function"},{"inputs":[],"name":"getLastInvariant","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"enum IPriceOracle.Variable","name":"variable","type":"uint8"}],"name":"getLatest","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"getMiscData","outputs":[{"internalType":"int256","name":"logInvariant","type":"int256"},{"internalType":"int256","name":"logTotalSupply","type":"int256"},{"internalType":"uint256","name":"oracleSampleCreationTimestamp","type":"uint256"},{"internalType":"uint256","name":"oracleIndex","type":"uint256"},{"internalType":"bool","name":"oracleEnabled","type":"bool"},{"internalType":"uint256","name":"swapFeePercentage","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"getNormalizedWeights","outputs":[{"internalType":"uint256[]","name":"","type":"uint256[]"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"getOwner","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"components":[{"internalType":"enum IPriceOracle.Variable","name":"variable","type":"uint8"},{"internalType":"uint256","name":"ago","type":"uint256"}],"internalType":"struct IPriceOracle.OracleAccumulatorQuery[]","name":"queries","type":"tuple[]"}],"name":"getPastAccumulators","outputs":[{"internalType":"int256[]","name":"results","type":"int256[]"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"getPausedState","outputs":[{"internalType":"bool","name":"paused","type":"bool"},{"internalType":"uint256","name":"pauseWindowEndTime","type":"uint256"},{"internalType":"uint256","name":"bufferPeriodEndTime","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"getPoolId","outputs":[{"internalType":"bytes32","name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"getRate","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"index","type":"uint256"}],"name":"getSample","outputs":[{"internalType":"int256","name":"logPairPrice","type":"int256"},{"internalType":"int256","name":"accLogPairPrice","type":"int256"},{"internalType":"int256","name":"logBptPrice","type":"int256"},{"internalType":"int256","name":"accLogBptPrice","type":"int256"},{"internalType":"int256","name":"logInvariant","type":"int256"},{"internalType":"int256","name":"accLogInvariant","type":"int256"},{"internalType":"uint256","name":"timestamp","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"getSwapFeePercentage","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"components":[{"internalType":"enum IPriceOracle.Variable","name":"variable","type":"uint8"},{"internalType":"uint256","name":"secs","type":"uint256"},{"internalType":"uint256","name":"ago","type":"uint256"}],"internalType":"struct IPriceOracle.OracleAverageQuery[]","name":"queries","type":"tuple[]"}],"name":"getTimeWeightedAverage","outputs":[{"internalType":"uint256[]","name":"results","type":"uint256[]"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"getTotalSamples","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"pure","type":"function"},{"inputs":[],"name":"getVault","outputs":[{"internalType":"contract IVault","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"increaseApproval","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"owner","type":"address"}],"name":"nonces","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"bytes32","name":"poolId","type":"bytes32"},{"internalType":"address","name":"sender","type":"address"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256[]","name":"balances","type":"uint256[]"},{"internalType":"uint256","name":"lastChangeBlock","type":"uint256"},{"internalType":"uint256","name":"protocolSwapFeePercentage","type":"uint256"},{"internalType":"bytes","name":"userData","type":"bytes"}],"name":"onExitPool","outputs":[{"internalType":"uint256[]","name":"","type":"uint256[]"},{"internalType":"uint256[]","name":"","type":"uint256[]"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"bytes32","name":"poolId","type":"bytes32"},{"internalType":"address","name":"sender","type":"address"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256[]","name":"balances","type":"uint256[]"},{"internalType":"uint256","name":"lastChangeBlock","type":"uint256"},{"internalType":"uint256","name":"protocolSwapFeePercentage","type":"uint256"},{"internalType":"bytes","name":"userData","type":"bytes"}],"name":"onJoinPool","outputs":[{"internalType":"uint256[]","name":"amountsIn","type":"uint256[]"},{"internalType":"uint256[]","name":"dueProtocolFeeAmounts","type":"uint256[]"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"components":[{"internalType":"enum IVault.SwapKind","name":"kind","type":"uint8"},{"internalType":"contract IERC20","name":"tokenIn","type":"address"},{"internalType":"contract IERC20","name":"tokenOut","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"},{"internalType":"bytes32","name":"poolId","type":"bytes32"},{"internalType":"uint256","name":"lastChangeBlock","type":"uint256"},{"internalType":"address","name":"from","type":"address"},{"internalType":"address","name":"to","type":"address"},{"internalType":"bytes","name":"userData","type":"bytes"}],"internalType":"struct IPoolSwapStructs.SwapRequest","name":"request","type":"tuple"},{"internalType":"uint256","name":"balanceTokenIn","type":"uint256"},{"internalType":"uint256","name":"balanceTokenOut","type":"uint256"}],"name":"onSwap","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"owner","type":"address"},{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"value","type":"uint256"},{"internalType":"uint256","name":"deadline","type":"uint256"},{"internalType":"uint8","name":"v","type":"uint8"},{"internalType":"bytes32","name":"r","type":"bytes32"},{"internalType":"bytes32","name":"s","type":"bytes32"}],"name":"permit","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"bytes32","name":"poolId","type":"bytes32"},{"internalType":"address","name":"sender","type":"address"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256[]","name":"balances","type":"uint256[]"},{"internalType":"uint256","name":"lastChangeBlock","type":"uint256"},{"internalType":"uint256","name":"protocolSwapFeePercentage","type":"uint256"},{"internalType":"bytes","name":"userData","type":"bytes"}],"name":"queryExit","outputs":[{"internalType":"uint256","name":"bptIn","type":"uint256"},{"internalType":"uint256[]","name":"amountsOut","type":"uint256[]"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"bytes32","name":"poolId","type":"bytes32"},{"internalType":"address","name":"sender","type":"address"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256[]","name":"balances","type":"uint256[]"},{"internalType":"uint256","name":"lastChangeBlock","type":"uint256"},{"internalType":"uint256","name":"protocolSwapFeePercentage","type":"uint256"},{"internalType":"bytes","name":"userData","type":"bytes"}],"name":"queryJoin","outputs":[{"internalType":"uint256","name":"bptOut","type":"uint256"},{"internalType":"uint256[]","name":"amountsIn","type":"uint256[]"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"bool","name":"paused","type":"bool"}],"name":"setPaused","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"uint256","name":"swapFeePercentage","type":"uint256"}],"name":"setSwapFeePercentage","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalSupply","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"sender","type":"address"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"transferFrom","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"}]