Contract Name:
ReserveManager
Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "openzeppelin-contracts/contracts/access/Ownable.sol";
import "openzeppelin-contracts/contracts/security/ReentrancyGuard.sol";
import "openzeppelin-contracts/contracts/token/ERC20/utils/SafeERC20.sol";
import "../../interfaces/IApeFinance.sol";
import "../../interfaces/IBurner.sol";
import "../../libraries/DataTypes.sol";
import "../../libraries/PauseFlags.sol";
contract ReserveManager is Ownable, ReentrancyGuard {
using SafeERC20 for IERC20;
using PauseFlags for DataTypes.MarketConfig;
/// @notice The maximum ratio
uint16 internal constant MAX_RATIO = 10000; // 100%
/// @notice The maximum reserve factor
uint16 internal constant MAX_RESERVE_FACTOR = 10000; // 100%
/// @notice The ApeFinance contract
IApeFinance public immutable apeFinance;
/// @notice The USDB token address
address public immutable apeUSD;
/// @notice The operator address
address public operator;
/// @notice The treasury address
address public treasury;
/// @notice The fee distribution address
address public feeDist;
/// @notice The ratio of the reserves to reduce
uint16 public reduceRatio;
/// @notice The revenue sharing ratio
uint16 public revenueSharingRatio;
/// @notice The reserves snapshot of each market
mapping(address => uint256) public reservesSnapshots;
struct Burner {
bool manualBurn;
address burner;
}
/// @notice The burners of each market
mapping(address => Burner) public burners;
event OperatorSet(address operator);
event TokenSeized(address token, uint256 amount);
event ReduceRatioSet(uint16 oldRatio, uint16 newRatio);
event RevenueSharingRatioSet(uint16 oldRatio, uint16 newRatio);
event BurnerSet(address market, address burner);
event TreasurySet(address treasury);
event FeeDistSet(address feeDist);
modifier onlyOperator() {
_checkOperator();
_;
}
constructor(address apeFinance_, address apeUSD_) {
apeFinance = IApeFinance(apeFinance_);
apeUSD = apeUSD_;
reduceRatio = 5000; // 50%
revenueSharingRatio = 7000; // 70%
}
/**
* @notice Absorbs the excessive cash to the reserves.
* @param markets The addresses of the markets
*/
function absorbToReserves(address[] memory markets) external onlyOperator {
for (uint256 i = 0; i < markets.length;) {
_absorbToReserves(markets[i]);
unchecked {
i++;
}
}
}
/**
* @notice Reduces the reserves from ApeFinance.
* @param markets The addresses of the markets
*/
function reduceReserves(address[] memory markets) external onlyOperator {
for (uint256 i = 0; i < markets.length;) {
address market = markets[i];
_absorbToReserves(market);
uint256 totalReserves = apeFinance.getTotalReserves(market);
if (totalReserves > reservesSnapshots[market]) {
uint256 reduceAmount = (totalReserves - reservesSnapshots[market]) * reduceRatio / 10000;
_reduceReserves(market, reduceAmount, address(this));
// Fetch total reserves again for updating the snapshot.
reservesSnapshots[market] = apeFinance.getTotalReserves(market);
}
unchecked {
i++;
}
}
}
/**
* @notice Reduces all the reserves from ApeFinance.
* @dev The market must be soft delisted to reduce all the reserves.
* @param market The address of the market
*/
function reduceFullReserves(address market) external onlyOperator {
DataTypes.MarketConfig memory config = apeFinance.getMarketConfiguration(market);
bool isSoftDelisted =
config.isSupplyPaused() && config.isBorrowPaused() && config.reserveFactor == MAX_RESERVE_FACTOR;
require(isSoftDelisted, "market is not soft delisted");
_absorbToReserves(market);
uint256 totalReserves = apeFinance.getTotalReserves(market);
_reduceReserves(market, totalReserves, address(this));
delete reservesSnapshots[market];
}
struct ConvertParams {
address token;
uint256 amountIn;
uint256 amountOutMin;
bytes path;
}
/**
* @notice Converts the reserves to USDB.
* @param convertParams The parameters of the conversion
* @param dispatch Whether to dispatch the USDB
*/
function convertReserves(ConvertParams[] memory convertParams, bool dispatch) external nonReentrant onlyOperator {
for (uint256 i = 0; i < convertParams.length;) {
address token = convertParams[i].token;
Burner memory b = burners[token];
require(b.burner != address(0), "burner not found");
if (b.manualBurn) {
// Send the reserves to the manual burner directly.
IERC20(token).safeTransfer(b.burner, convertParams[i].amountIn);
} else {
IERC20(token).safeIncreaseAllowance(b.burner, convertParams[i].amountIn);
// Convert the reserves to USDB.
IBurner(b.burner).burn(
token, convertParams[i].amountIn, convertParams[i].amountOutMin, convertParams[i].path
);
}
unchecked {
i++;
}
}
if (dispatch) {
_dispatch();
}
}
/**
* @notice Dispatches the USDB to the fee distribution contract and the treasury.
*/
function dispatchRewards() external onlyOperator {
_dispatch();
}
/* ========== RESTRICTED FUNCTIONS ========== */
/**
* @notice Sets the operator address
* @param _operator The operator address
*/
function setOperator(address _operator) external onlyOwner {
operator = _operator;
emit OperatorSet(_operator);
}
/**
* @notice Seize the token from the contract.
* @param token The address of the token
* @param amount The amount to seize
* @param recipient The address of the recipient
*/
function seize(address token, uint256 amount, address recipient) external onlyOwner {
IERC20(token).safeTransfer(recipient, amount);
emit TokenSeized(token, amount);
}
/**
* @notice Set the reduce ratio.
* @param newRatio The new ratio
*/
function setReduceRatio(uint16 newRatio) external onlyOwner {
require(newRatio <= MAX_RATIO, "invalid ratio");
uint16 oldRatio = reduceRatio;
reduceRatio = newRatio;
emit ReduceRatioSet(oldRatio, newRatio);
}
/**
* @notice Set the revenue sharing ratio.
* @param newRatio The new ratio
*/
function setRevenueSharingRatio(uint16 newRatio) external onlyOwner {
require(newRatio <= MAX_RATIO, "invalid ratio");
uint16 oldRatio = revenueSharingRatio;
revenueSharingRatio = newRatio;
emit RevenueSharingRatioSet(oldRatio, newRatio);
}
/**
* @notice Set the burner of the market.
* @param market The address of the market
* @param manualBurn Whether to manually burn the reserves
* @param burner The address of the burner
*/
function setBurner(address market, bool manualBurn, address burner) external onlyOwner {
burners[market] = Burner({manualBurn: manualBurn, burner: burner});
emit BurnerSet(market, burner);
}
/**
* @notice Set the treasury address.
* @param _treasury The address of the treasury
*/
function setTreasury(address _treasury) external onlyOwner {
treasury = _treasury;
emit TreasurySet(_treasury);
}
/**
* @notice Set the fee distribution address.
* @param _feeDist The address of the fee distribution
*/
function setFeeDist(address _feeDist) external onlyOwner {
feeDist = _feeDist;
emit FeeDistSet(_feeDist);
}
/* ========== INTERNAL FUNCTIONS ========== */
/**
* @dev Checks whether the caller is the operator.
*/
function _checkOperator() internal view {
require(msg.sender == operator, "caller is not the operator");
}
/**
* @dev Absorbs the excessive cash to the reserves.
* @param market The address of the market
*/
function _absorbToReserves(address market) internal {
apeFinance.absorbToReserves(market);
}
/**
* @dev Reduces the reserves from ApeFinance.
* @param market The address of the market
* @param reduceAmount The amount to reduce
* @param recipient The address of the recipient
*/
function _reduceReserves(address market, uint256 reduceAmount, address recipient) internal {
apeFinance.reduceReserves(market, reduceAmount, recipient);
}
/**
* @dev Dispatches the USDB to the fee distribution contract and the treasury.
*/
function _dispatch() internal {
uint256 balance = IERC20(apeUSD).balanceOf(address(this));
uint256 amountToDispatch = balance * revenueSharingRatio / 10000;
uint256 amountToTreasury = balance - amountToDispatch;
if (amountToDispatch > 0) {
require(feeDist != address(0), "fee dist not set");
IERC20(apeUSD).safeTransfer(feeDist, amountToDispatch);
}
if (amountToTreasury > 0) {
require(treasury != address(0), "treasury not set");
IERC20(apeUSD).safeTransfer(treasury, amountToTreasury);
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() {
_transferOwnership(_msgSender());
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/
function _checkOwner() internal view virtual {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (security/ReentrancyGuard.sol)
pragma solidity ^0.8.0;
/**
* @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 making it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
_nonReentrantBefore();
_;
_nonReentrantAfter();
}
function _nonReentrantBefore() private {
// On the first call to nonReentrant, _status will be _NOT_ENTERED
require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
// Any calls to nonReentrant after this point will fail
_status = _ENTERED;
}
function _nonReentrantAfter() 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
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/utils/SafeERC20.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
import "../extensions/draft-IERC20Permit.sol";
import "../../../utils/Address.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 {
using Address for address;
function safeTransfer(
IERC20 token,
address to,
uint256 value
) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
function safeTransferFrom(
IERC20 token,
address from,
address to,
uint256 value
) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
/**
* @dev Deprecated. This function has issues similar to the ones found in
* {IERC20-approve}, and its usage is discouraged.
*
* Whenever possible, use {safeIncreaseAllowance} and
* {safeDecreaseAllowance} instead.
*/
function safeApprove(
IERC20 token,
address spender,
uint256 value
) internal {
// safeApprove should only be called when setting an initial allowance,
// or when resetting it to zero. To increase and decrease it, use
// 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
require(
(value == 0) || (token.allowance(address(this), spender) == 0),
"SafeERC20: approve from non-zero to non-zero allowance"
);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
}
function safeIncreaseAllowance(
IERC20 token,
address spender,
uint256 value
) internal {
uint256 newAllowance = token.allowance(address(this), spender) + value;
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
function safeDecreaseAllowance(
IERC20 token,
address spender,
uint256 value
) internal {
unchecked {
uint256 oldAllowance = token.allowance(address(this), spender);
require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
uint256 newAllowance = oldAllowance - value;
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
}
function safePermit(
IERC20Permit token,
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) internal {
uint256 nonceBefore = token.nonces(owner);
token.permit(owner, spender, value, deadline, v, r, s);
uint256 nonceAfter = token.nonces(owner);
require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
}
/**
* @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).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*/
function _callOptionalReturn(IERC20 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. We use {Address-functionCall} to perform this call, which verifies that
// the target address contains contract code and also asserts for success in the low-level call.
bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
if (returndata.length > 0) {
// Return data is optional
require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../libraries/DataTypes.sol";
interface IApeFinance {
/* ========== USER INTERFACES ========== */
function accrueInterest(address market) external;
function supply(address from, address to, address market, uint256 amount) external;
function borrow(address from, address to, address asset, uint256 amount) external;
function redeem(address from, address to, address asset, uint256 amount) external returns (uint256);
function repay(address from, address to, address asset, uint256 amount) external returns (uint256);
function liquidate(
address liquidator,
address borrower,
address marketBorrow,
address marketCollateral,
uint256 repayAmount
) external returns (uint256, uint256);
function deferLiquidityCheck(address user, bytes memory data) external;
function getBorrowBalance(address user, address market) external view returns (uint256);
function getATokenBalance(address user, address market) external view returns (uint256);
function getSupplyBalance(address user, address market) external view returns (uint256);
function isMarketListed(address market) external view returns (bool);
function getExchangeRate(address market) external view returns (uint256);
function getTotalSupply(address market) external view returns (uint256);
function getTotalBorrow(address market) external view returns (uint256);
function getTotalCash(address market) external view returns (uint256);
function getTotalReserves(address market) external view returns (uint256);
function getAccountLiquidity(address user) external view returns (uint256, uint256, uint256);
function isAllowedExtension(address user, address extension) external view returns (bool);
function transferAToken(address market, address from, address to, uint256 amount) external;
function setSubAccountExtension(address primary, uint256 subAccountId, bool allowed) external;
/* ========== MARKET CONFIGURATOR INTERFACES ========== */
function getMarketConfiguration(address market) external view returns (DataTypes.MarketConfig memory);
function listMarket(address market, DataTypes.MarketConfig calldata config) external;
function delistMarket(address market) external;
function setMarketConfiguration(address market, DataTypes.MarketConfig calldata config) external;
/* ========== CREDIT LIMIT MANAGER INTERFACES ========== */
function getCreditLimit(address user, address market) external view returns (uint256);
function getUserCreditMarkets(address user) external view returns (address[] memory);
function isCreditAccount(address user) external view returns (bool);
function setCreditLimit(address user, address market, uint256 credit) external;
/* ========== RESERVE MANAGER INTERFACES ========== */
function absorbToReserves(address market) external;
function reduceReserves(address market, uint256 aTokenAmount, address recipient) external;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
interface IBurner {
function burn(address token, uint256 amountIn, uint256 amountOutMin, bytes memory path)
external
returns (uint256 amountOut);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
library DataTypes {
struct UserBorrow {
uint256 borrowBalance;
uint256 borrowIndex;
}
struct MarketConfig {
// 1 + 1 + 2 + 2 + 2 + 2 + 1 + 1 = 12
bool isListed;
uint8 pauseFlags;
uint16 collateralFactor;
uint16 liquidationThreshold;
uint16 liquidationBonus;
uint16 reserveFactor;
bool isPToken;
bool isDelisted;
// 20 + 20 + 20 + 32 + 32 + 32
address aTokenAddress;
address debtTokenAddress;
address interestRateModelAddress;
uint256 supplyCap;
uint256 borrowCap;
uint256 initialExchangeRate;
}
struct Market {
MarketConfig config;
uint40 lastUpdateTimestamp;
uint256 totalCash;
uint256 totalBorrow;
uint256 totalSupply;
uint256 totalReserves;
uint256 borrowIndex;
mapping(address => UserBorrow) userBorrows;
mapping(address => uint256) userSupplies;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./DataTypes.sol";
library PauseFlags {
/// @dev Mask for specific actions in the pause flag bit array
uint8 internal constant PAUSE_SUPPLY_MASK = 0xFE;
uint8 internal constant PAUSE_BORROW_MASK = 0xFD;
uint8 internal constant PAUSE_TRANSFER_MASK = 0xFB;
/// @dev Offsets for specific actions in the pause flag bit array
uint8 internal constant PAUSE_SUPPLY_OFFSET = 0;
uint8 internal constant PAUSE_BORROW_OFFSET = 1;
uint8 internal constant PAUSE_TRANSFER_OFFSET = 2;
/// @dev Sets the market supply paused.
function setSupplyPaused(DataTypes.MarketConfig memory self, bool paused) internal pure {
self.pauseFlags = (self.pauseFlags & PAUSE_SUPPLY_MASK) | (toUInt8(paused) << PAUSE_SUPPLY_OFFSET);
}
/// @dev Returns true if the market supply is paused, and false otherwise.
function isSupplyPaused(DataTypes.MarketConfig memory self) internal pure returns (bool) {
return toBool(self.pauseFlags & ~PAUSE_SUPPLY_MASK);
}
/// @dev Sets the market borrow paused.
function setBorrowPaused(DataTypes.MarketConfig memory self, bool paused) internal pure {
self.pauseFlags = (self.pauseFlags & PAUSE_BORROW_MASK) | (toUInt8(paused) << PAUSE_BORROW_OFFSET);
}
/// @dev Returns true if the market borrow is paused, and false otherwise.
function isBorrowPaused(DataTypes.MarketConfig memory self) internal pure returns (bool) {
return toBool(self.pauseFlags & ~PAUSE_BORROW_MASK);
}
/// @dev Sets the market transfer paused.
function setTransferPaused(DataTypes.MarketConfig memory self, bool paused) internal pure {
self.pauseFlags = (self.pauseFlags & PAUSE_TRANSFER_MASK) | (toUInt8(paused) << PAUSE_TRANSFER_OFFSET);
}
/// @dev Returns true if the market transfer is paused, and false otherwise.
function isTransferPaused(DataTypes.MarketConfig memory self) internal pure returns (bool) {
return toBool(self.pauseFlags & ~PAUSE_TRANSFER_MASK);
}
/// @dev Casts a boolean to uint8.
function toUInt8(bool x) internal pure returns (uint8) {
return x ? 1 : 0;
}
/// @dev Casts a uint8 to boolean.
function toBool(uint8 x) internal pure returns (bool) {
return x != 0;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @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);
/**
* @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 `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address to, 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 `from` to `to` 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 from,
address to,
uint256 amount
) external returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)
pragma solidity ^0.8.0;
/**
* @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: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*
* [IMPORTANT]
* ====
* You shouldn't rely on `isContract` to protect against flash loan attacks!
*
* Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
* like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
* constructor.
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize/address.code.length, which returns 0
// for contracts in construction, since the code is only stored at the end
// of the constructor execution.
return account.code.length > 0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
(bool success, ) = recipient.call{value: amount}("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain `call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value
) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value,
string memory errorMessage
) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(
address target,
bytes memory data,
string memory errorMessage
) internal view returns (bytes memory) {
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
* the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
*
* _Available since v4.8._
*/
function verifyCallResultFromTarget(
address target,
bool success,
bytes memory returndata,
string memory errorMessage
) internal view returns (bytes memory) {
if (success) {
if (returndata.length == 0) {
// only check isContract if the call was successful and the return data is empty
// otherwise we already know that it was a contract
require(isContract(target), "Address: call to non-contract");
}
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
/**
* @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason or using the provided one.
*
* _Available since v4.3._
*/
function verifyCallResult(
bool success,
bytes memory returndata,
string memory errorMessage
) internal pure returns (bytes memory) {
if (success) {
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
function _revert(bytes memory returndata, string memory errorMessage) private pure {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
/// @solidity memory-safe-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}