Contract Source Code:
pragma solidity ^0.8.22;
import '@uniswap/v2-core/contracts/interfaces/IUniswapV2Pair.sol';
import '@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol';
import '@openzeppelin/contracts/access/Ownable.sol';
import "abdk-libraries-solidity/ABDKMath64x64.sol";
import './ERC20PresetMinterRebaser.sol';
import './interfaces/ISoup.sol';
// Welcome to THE SOUP GAME.
// lfg to https://soup.game and play.
//
// Yes, this contract will be renounced once game
// mechanics are proven to be fair and balanced.
//
// SOUP, because... it's what the people want.
// Obviously.
/**
* @title Soup Token Contract
* @dev ERC20 token with deflationary mechanics and reward freezing functionality
*/
contract Soup is ERC20PresetMinterRebaser, Ownable {
using ABDKMath64x64 for int128;
/**
* @notice Internal decimals used to handle scaling factor
*/
uint256 public constant internalDecimals = 10**18;
int128 public MIN_SCALE_FACTOR = ABDKMath64x64.fromUInt(1e9).div(ABDKMath64x64.fromUInt(10**18));
mapping(address => uint256) internal _soupBalances;
mapping(address => mapping(address => uint256)) internal _allowedFragments;
int128 public deflationRate;
uint256 public _debaseStartedAt;
uint256 public _lastDebasedAt;
uint256 public rewardsRequestedAt;
uint256 public totalUnderlyingSupply;
uint256 public _frozen;
// keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
bytes32 public constant PERMIT_TYPEHASH =
0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
bytes32 public DOMAIN_SEPARATOR;
mapping(address => uint256) public nonces;
/// @notice The EIP-712 typehash for the contract's domain
bytes32 public constant DOMAIN_TYPEHASH =
keccak256("EIP712Domain(string name,uint256 chainId,address verifyingContract)");
uint256 public initialSupply;
// Soup island:
uint256 public frozenForRewards;
event Mint(address to, uint256 amount);
event Burn(address from, uint256 amount);
modifier validRecipient(address to) {
require(to != address(0));
require(to != address(this));
_;
}
int128 public scaleFactor;
/**
* @dev Constructor initializes the token with an initial supply and sets the domain separator
*/
constructor() ERC20PresetMinterRebaser("soup.game", "SOUP") {
initialSupply = 100_000_000 * 10**decimals();
setDomainSeparator();
int128 one = ABDKMath64x64.fromUInt(1);
deflationRate = one.sub(ABDKMath64x64.divu(3, 10000000));
scaleFactor = deflationRate.pow(0);
uint256 rewards = initialSupply * 7 / 10;
freezeForRewards(rewards);
_mint(owner(), initialSupply - rewards);
}
/**
* @dev Sets the domain separator for EIP-712
*/
function setDomainSeparator() internal {
uint256 chainId_;
assembly { chainId_ := chainid() }
DOMAIN_SEPARATOR = keccak256(
abi.encode(
keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"),
keccak256(bytes("SOUP")),
keccak256(bytes("1")),
chainId_,
address(this)
)
);
}
/**
* @dev Starts the debase process by setting the debase start timestamp
*/
function startDebase() external onlyOwner {
_debaseStartedAt = block.timestamp;
}
/**
* @notice Gets the timestamp when debase started
* @return The timestamp when debase started
*/
function debaseStartedAt() public view returns (uint256){
return _debaseStartedAt == 0 ? block.timestamp : _debaseStartedAt;
}
/**
* @notice Gets the current scaling factor
* @return The current scaling factor
*/
function soupScalingFactor() public view returns (uint256) {
return scaleFactor.mulu(internalDecimals);
}
/**
* @notice Gets the duration of the debase period
* @return The duration of the debase period in seconds
*/
function debaseDuration() public view returns (uint256) {
return block.timestamp - debaseStartedAt();
}
/**
* @dev Debases the token by updating the scaling factor
*/
function debase() public {
if ( _debaseStartedAt > 0 && block.timestamp - _lastDebasedAt > 60) {
int128 newScaleFactor = deflationRate.pow(debaseDuration());
if (newScaleFactor >= MIN_SCALE_FACTOR) {
_lastDebasedAt = block.timestamp;
scaleFactor = newScaleFactor;
if (address(lpPair) != address(0)) lpPair.sync();
}
}
}
/**
* @notice Gets the total supply of tokens
* @return The total supply of tokens
*/
function totalSupply() public view override returns (uint256) {
return maxSupply() - frozenForRewards;
}
/**
* @notice Gets the total liquid supply of tokens
* @return The total liquid supply of tokens
*/
function totalLiquidSupply() public view returns (uint256) {
return _soupToFragment(totalUnderlyingSupply);
}
/**
* @notice Gets the maximum supply of tokens
* @return The maximum supply of tokens
*/
function maxSupply() public view returns (uint256) {
return totalLiquidSupply() + _frozen;
}
/**
* @notice Gets the maximum scaling factor
* @return The maximum scaling factor
*/
function maxScalingFactor() public view returns (uint256) {
return uint256(int256(-1)) / totalUnderlyingSupply;
}
/**
* @notice Requests a percentage of the remaining
* rewards by unfreezing tokens
* @param rewardBips Basis points of the rewards to request
*/
function requestRewards(uint256 rewardBips) external {
require(hasRole(MINTER_ROLE, _msgSender()), "Must have minter role");
uint256 amount = frozenForRewards * rewardBips / 10_000;
frozenForRewards -= amount;
unfreeze(msg.sender, amount);
}
/**
* @dev Freezes tokens for rewards
* @param amount The amount of tokens to freeze
*/
function freezeForRewards(uint256 amount) internal {
frozenForRewards = amount;
_frozen += amount;
}
/**
* @notice Freezes tokens from the caller's balance
* @param amount The amount of tokens to freeze
*/
function freeze(uint256 amount) public {
require(hasRole(MINTER_ROLE, _msgSender()), "Must have minter role");
_burn(amount, msg.sender);
_frozen += amount;
}
/**
* @notice Unfreezes tokens to a specified address
* @param to The address to receive the unfrozen tokens
* @param amount The amount of tokens to unfreeze
* @return True on success, false otherwise
*/
function unfreeze(address to, uint256 amount) public returns (bool) {
require(hasRole(MINTER_ROLE, _msgSender()), "Must have minter role");
_frozen -= amount;
_mint(to, amount);
return true;
}
/**
* @notice Mints new tokens, increasing totalSupply, totalUnderlyingSupply, and the user's balance
* @param to The address to receive the minted tokens
* @param amount The amount of tokens to mint
* @return True on success, false otherwise
*/
function mint(address to, uint256 amount) external returns (bool) {
require(hasRole(MINTER_ROLE, _msgSender()), "Must have minter role");
_mint(to, amount);
return true;
}
/**
* @dev Internal function to mint new tokens
* @param to The address to receive the minted tokens
* @param amount The amount of tokens to mint
*/
function _mint(address to, uint256 amount) internal override {
uint256 soupValue = _fragmentToSoup(amount);
totalUnderlyingSupply += soupValue;
_soupBalances[to] += soupValue;
emit Mint(to, amount);
emit Transfer(address(0), to, amount);
}
/**
* @notice Burns tokens from the caller's balance
* @param amount The amount of tokens to burn
*/
function burn(uint256 amount) public override {
_burn(amount, msg.sender);
}
/**
* @dev Internal function to burn tokens from a specified address
* @param amount The amount of tokens to burn
* @param from The address from which to burn tokens
*/
function _burn(uint256 amount, address from) internal {
uint256 soupValue = _fragmentToSoup(amount);
totalUnderlyingSupply -= soupValue;
_soupBalances[from] -= soupValue;
emit Burn(from, amount);
emit Transfer(from, address(0), amount);
}
/**
* @notice Mints new tokens using underlying amount,
* increasing totalSupply, totalUnderlyingSupply, and the user's balance
*
* @param to The address to receive the minted tokens
* @param amount The amount of underlying tokens to mint
* @return True on success, false otherwise
*/
function mintUnderlying(address to, uint256 amount) public returns (bool) {
require(hasRole(MINTER_ROLE, _msgSender()), "Must have minter role");
_mintUnderlying(to, amount);
return true;
}
/**
* @dev Internal function to mint new tokens using underlying amount
* @param to The address to receive the minted tokens
* @param amount The amount of underlying tokens to mint
*/
function _mintUnderlying(address to, uint256 amount) internal {
uint256 scaledAmount = _soupToFragment(amount);
totalUnderlyingSupply += amount;
_soupBalances[to] += amount;
emit Mint(to, scaledAmount);
emit Transfer(address(0), to, scaledAmount);
}
/**
* @notice Transfers underlying balance to a specified address
* @param to The address to transfer to
* @param value The amount to be transferred
* @return True on success, false otherwise
*/
function transferUnderlying(address to, uint256 value) public validRecipient(to) returns (bool) {
_soupBalances[msg.sender] -= value;
_soupBalances[to] += value;
emit Transfer(msg.sender, to, _soupToFragment(value));
return true;
}
/* - ERC20 functionality - */
/**
* @notice Transfers tokens to a specified address
* @param to The address to transfer to
* @param value The amount to be transferred
* @return True on success, false otherwise
*/
function transfer(address to, uint256 value) public override validRecipient(to) returns (bool) {
uint256 soupValue = _fragmentToSoup(value);
_soupBalances[msg.sender] -= soupValue;
_soupBalances[to] += soupValue;
emit Transfer(msg.sender, to, value);
return true;
}
IUniswapV2Pair public lpPair;
/**
* @notice Sets the Uniswap pair address
* @param pairAddress The address of the Uniswap pair
*/
function setPair(IUniswapV2Pair pairAddress) external onlyOwner {
lpPair = pairAddress;
}
/**
* @notice Transfers tokens from one address to another
* @param from The address to send tokens from
* @param to The address to transfer to
* @param value The amount of tokens to be transferred
* @return True on success, false otherwise
*/
function transferFrom(address from, address to, uint256 value) public override validRecipient(to) returns (bool) {
_allowedFragments[from][msg.sender] = _allowedFragments[from][msg.sender] - value;
uint256 soupValue = _fragmentToSoup(value);
_soupBalances[from] = _soupBalances[from] - soupValue;
_soupBalances[to] = _soupBalances[to] + soupValue;
emit Transfer(from, to, value);
return true;
}
/**
* @notice Gets the balance of a specified address
* @param who The address to query
* @return The balance of the specified address
*/
function balanceOf(address who) public view override returns (uint256) {
return _soupToFragment(_soupBalances[who]);
}
/**
* @notice Gets the underlying balance of a specified address
* @param who The address to query
* @return The underlying balance of the specified address
*/
function balanceOfUnderlying(address who) public view returns (uint256) {
return _soupBalances[who];
}
/**
* @notice Gets the amount of tokens that an owner has allowed to a spender
* @param owner_ The address which owns the funds
* @param spender The address which will spend the funds
* @return The number of tokens still available for the spender
*/
function allowance(address owner_, address spender) public view override returns (uint256) {
return _allowedFragments[owner_][spender];
}
/**
* @notice Approves the passed address to spend the specified amount of tokens on behalf of msg.sender
* @param spender The address which will spend the funds
* @param value The amount of tokens to be spent
* @return True on success, false otherwise
*/
function approve(address spender, uint256 value) public override returns (bool) {
_allowedFragments[msg.sender][spender] = value;
emit Approval(msg.sender, spender, value);
return true;
}
/**
* @notice Increases the amount of tokens that an owner has allowed to a spender
* @param spender The address which will spend the funds
* @param addedValue The amount of tokens to increase the allowance by
* @return True on success, false otherwise
*/
function increaseAllowance(address spender, uint256 addedValue) public override returns (bool) {
_allowedFragments[msg.sender][spender] = addedValue;
emit Approval(msg.sender, spender, _allowedFragments[msg.sender][spender]);
return true;
}
/**
* @notice Decreases the amount of tokens that an owner has allowed to a spender
* @param spender The address which will spend the funds
* @param subtractedValue The amount of tokens to decrease the allowance by
* @return True on success, false otherwise
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public override returns (bool) {
uint256 oldValue = _allowedFragments[msg.sender][spender];
if (subtractedValue >= oldValue)
_allowedFragments[msg.sender][spender] = 0;
else _allowedFragments[msg.sender][spender] = oldValue - subtractedValue;
emit Approval(msg.sender, spender, _allowedFragments[msg.sender][spender]);
return true;
}
/**
* @notice Approves a spender via signature
* @param owner The address which owns the funds
* @param spender The address which will spend the funds
* @param value The amount of tokens to be spent
* @param deadline The deadline for the approval to be valid
* @param v The recovery byte of the signature
* @param r Half of the ECDSA signature pair
* @param s Half of the ECDSA signature pair
*/
function permit(
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) public {
require(block.timestamp <= deadline, "SOUP/permit-expired");
bytes32 digest = keccak256(
abi.encodePacked(
"\x19\x01",
DOMAIN_SEPARATOR,
keccak256(
abi.encode(
PERMIT_TYPEHASH,
owner,
spender,
value,
nonces[owner]++,
deadline
)
)
)
);
require(owner != address(0), "SOUP/invalid-address-0");
require(owner == ecrecover(digest, v, r, s), "SOUP/invalid-permit");
_allowedFragments[owner][spender] = value;
emit Approval(owner, spender, value);
}
/**
* @notice Converts soup units to fragment units
* @param soup The amount of soup to convert
* @return The converted amount in fragment units
*/
function soupToFragment(uint256 soup) public view returns (uint256) {
return _soupToFragment(soup);
}
/**
* @notice Converts fragment units to soup units
* @param value The amount of fragments to convert
* @return The converted amount in soup units
*/
function fragmentToSoup(uint256 value) public view returns (uint256) {
return _fragmentToSoup(value);
}
/**
* @dev Internal function to convert soup units to fragment units
* @param soup The amount of soup to convert
* @return The converted amount in fragment units
*/
function _soupToFragment(uint256 soup) internal view returns (uint256) {
return (soup * soupScalingFactor()) / internalDecimals;
}
/**
* @dev Internal function to convert fragment units to soup units
* @param value The amount of fragments to convert
* @return The converted amount in soup units
*/
function _fragmentToSoup(uint256 value) internal view returns (uint256) {
return (value * internalDecimals) / soupScalingFactor();
}
/**
* @notice Rescues tokens to a specified address
* @param token The address of the token contract
* @param to The address to receive the rescued tokens
* @param amount The amount of tokens to rescue
* @return True on success, false otherwise
*/
function rescueTokens(address token, address to, uint256 amount) public onlyOwner returns (bool) {
SafeERC20.safeTransfer(IERC20(token), to, amount);
return true;
}
/**
* @notice Reduces the numerical representation of frozen tokens
* @param leftover The amount of tokens to reduce
*/
function accountForDefrostedDeflation(uint256 leftover) external {
require(hasRole(MINTER_ROLE, _msgSender()), "Must have MINTER_ROLE");
// During defrost period, a portion of liquid soup is subject to deflation.
// But when the liquid Soup is recovered, there is no mathematical
// representation for the soup that deflated during it's defrost period,
// which is why this method is necessary.
//
// This function simply removes these leftover deflated tokens from the
// `_frozen` tally. They were never re-minted to begin with, so no burn is needed.
_frozen -= leftover;
}
}
pragma solidity ^0.8.22;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
interface ISoup is IERC20 {
function debase() external;
function burn(uint256 amount) external;
function freeze(uint256 amount) external;
function mint(address to, uint256 amount) external;
function deflationRate() external returns (int128);
function requestRewards(uint256 rewardBips) external;
function totalLiquidSupply() external view returns (uint256);
function accountForDefrostedDeflation(uint256 leftover) external;
function unfreeze(address to, uint256 amount) external returns (bool);
function soupToFragment(uint256 soup) external view returns (uint256);
function fragmentToSoup(uint256 value) external view returns (uint256);
function balanceOfUnderlying(address who) external view returns (uint256);
function transferUnderlying(address to, uint256 value) external returns (bool);
}
// File: contracts/ERC20PresetMinterRebaser.sol
pragma solidity ^0.8.0;
import '@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol';
import '@openzeppelin/contracts/access/AccessControlEnumerable.sol';
import '@openzeppelin/contracts/utils/Context.sol';
contract ERC20PresetMinterRebaser is
Context,
AccessControlEnumerable,
ERC20Burnable
{
bytes32 public constant MINTER_ROLE = keccak256("MINTER_ROLE");
bytes32 public constant REBASER_ROLE = keccak256("REBASER_ROLE");
constructor(string memory name, string memory symbol) ERC20(name, symbol) {
_setupRole(DEFAULT_ADMIN_ROLE, _msgSender());
_setupRole(MINTER_ROLE, _msgSender());
_setupRole(REBASER_ROLE, _msgSender());
}
}
// SPDX-License-Identifier: BSD-4-Clause
/*
* ABDK Math 64.64 Smart Contract Library. Copyright © 2019 by ABDK Consulting.
* Author: Mikhail Vladimirov <[email protected]>
*/
pragma solidity ^0.8.0;
/**
* Smart contract library of mathematical functions operating with signed
* 64.64-bit fixed point numbers. Signed 64.64-bit fixed point number is
* basically a simple fraction whose numerator is signed 128-bit integer and
* denominator is 2^64. As long as denominator is always the same, there is no
* need to store it, thus in Solidity signed 64.64-bit fixed point numbers are
* represented by int128 type holding only the numerator.
*/
library ABDKMath64x64 {
/*
* Minimum value signed 64.64-bit fixed point number may have.
*/
int128 private constant MIN_64x64 = -0x80000000000000000000000000000000;
/*
* Maximum value signed 64.64-bit fixed point number may have.
*/
int128 private constant MAX_64x64 = 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF;
/**
* Convert signed 256-bit integer number into signed 64.64-bit fixed point
* number. Revert on overflow.
*
* @param x signed 256-bit integer number
* @return signed 64.64-bit fixed point number
*/
function fromInt (int256 x) internal pure returns (int128) {
unchecked {
require (x >= -0x8000000000000000 && x <= 0x7FFFFFFFFFFFFFFF);
return int128 (x << 64);
}
}
/**
* Convert signed 64.64 fixed point number into signed 64-bit integer number
* rounding down.
*
* @param x signed 64.64-bit fixed point number
* @return signed 64-bit integer number
*/
function toInt (int128 x) internal pure returns (int64) {
unchecked {
return int64 (x >> 64);
}
}
/**
* Convert unsigned 256-bit integer number into signed 64.64-bit fixed point
* number. Revert on overflow.
*
* @param x unsigned 256-bit integer number
* @return signed 64.64-bit fixed point number
*/
function fromUInt (uint256 x) internal pure returns (int128) {
unchecked {
require (x <= 0x7FFFFFFFFFFFFFFF);
return int128 (int256 (x << 64));
}
}
/**
* Convert signed 64.64 fixed point number into unsigned 64-bit integer
* number rounding down. Revert on underflow.
*
* @param x signed 64.64-bit fixed point number
* @return unsigned 64-bit integer number
*/
function toUInt (int128 x) internal pure returns (uint64) {
unchecked {
require (x >= 0);
return uint64 (uint128 (x >> 64));
}
}
/**
* Convert signed 128.128 fixed point number into signed 64.64-bit fixed point
* number rounding down. Revert on overflow.
*
* @param x signed 128.128-bin fixed point number
* @return signed 64.64-bit fixed point number
*/
function from128x128 (int256 x) internal pure returns (int128) {
unchecked {
int256 result = x >> 64;
require (result >= MIN_64x64 && result <= MAX_64x64);
return int128 (result);
}
}
/**
* Convert signed 64.64 fixed point number into signed 128.128 fixed point
* number.
*
* @param x signed 64.64-bit fixed point number
* @return signed 128.128 fixed point number
*/
function to128x128 (int128 x) internal pure returns (int256) {
unchecked {
return int256 (x) << 64;
}
}
/**
* Calculate x + y. Revert on overflow.
*
* @param x signed 64.64-bit fixed point number
* @param y signed 64.64-bit fixed point number
* @return signed 64.64-bit fixed point number
*/
function add (int128 x, int128 y) internal pure returns (int128) {
unchecked {
int256 result = int256(x) + y;
require (result >= MIN_64x64 && result <= MAX_64x64);
return int128 (result);
}
}
/**
* Calculate x - y. Revert on overflow.
*
* @param x signed 64.64-bit fixed point number
* @param y signed 64.64-bit fixed point number
* @return signed 64.64-bit fixed point number
*/
function sub (int128 x, int128 y) internal pure returns (int128) {
unchecked {
int256 result = int256(x) - y;
require (result >= MIN_64x64 && result <= MAX_64x64);
return int128 (result);
}
}
/**
* Calculate x * y rounding down. Revert on overflow.
*
* @param x signed 64.64-bit fixed point number
* @param y signed 64.64-bit fixed point number
* @return signed 64.64-bit fixed point number
*/
function mul (int128 x, int128 y) internal pure returns (int128) {
unchecked {
int256 result = int256(x) * y >> 64;
require (result >= MIN_64x64 && result <= MAX_64x64);
return int128 (result);
}
}
/**
* Calculate x * y rounding towards zero, where x is signed 64.64 fixed point
* number and y is signed 256-bit integer number. Revert on overflow.
*
* @param x signed 64.64 fixed point number
* @param y signed 256-bit integer number
* @return signed 256-bit integer number
*/
function muli (int128 x, int256 y) internal pure returns (int256) {
unchecked {
if (x == MIN_64x64) {
require (y >= -0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF &&
y <= 0x1000000000000000000000000000000000000000000000000);
return -y << 63;
} else {
bool negativeResult = false;
if (x < 0) {
x = -x;
negativeResult = true;
}
if (y < 0) {
y = -y; // We rely on overflow behavior here
negativeResult = !negativeResult;
}
uint256 absoluteResult = mulu (x, uint256 (y));
if (negativeResult) {
require (absoluteResult <=
0x8000000000000000000000000000000000000000000000000000000000000000);
return -int256 (absoluteResult); // We rely on overflow behavior here
} else {
require (absoluteResult <=
0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF);
return int256 (absoluteResult);
}
}
}
}
/**
* Calculate x * y rounding down, where x is signed 64.64 fixed point number
* and y is unsigned 256-bit integer number. Revert on overflow.
*
* @param x signed 64.64 fixed point number
* @param y unsigned 256-bit integer number
* @return unsigned 256-bit integer number
*/
function mulu (int128 x, uint256 y) internal pure returns (uint256) {
unchecked {
if (y == 0) return 0;
require (x >= 0);
uint256 lo = (uint256 (int256 (x)) * (y & 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)) >> 64;
uint256 hi = uint256 (int256 (x)) * (y >> 128);
require (hi <= 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF);
hi <<= 64;
require (hi <=
0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF - lo);
return hi + lo;
}
}
/**
* Calculate x / y rounding towards zero. Revert on overflow or when y is
* zero.
*
* @param x signed 64.64-bit fixed point number
* @param y signed 64.64-bit fixed point number
* @return signed 64.64-bit fixed point number
*/
function div (int128 x, int128 y) internal pure returns (int128) {
unchecked {
require (y != 0);
int256 result = (int256 (x) << 64) / y;
require (result >= MIN_64x64 && result <= MAX_64x64);
return int128 (result);
}
}
/**
* Calculate x / y rounding towards zero, where x and y are signed 256-bit
* integer numbers. Revert on overflow or when y is zero.
*
* @param x signed 256-bit integer number
* @param y signed 256-bit integer number
* @return signed 64.64-bit fixed point number
*/
function divi (int256 x, int256 y) internal pure returns (int128) {
unchecked {
require (y != 0);
bool negativeResult = false;
if (x < 0) {
x = -x; // We rely on overflow behavior here
negativeResult = true;
}
if (y < 0) {
y = -y; // We rely on overflow behavior here
negativeResult = !negativeResult;
}
uint128 absoluteResult = divuu (uint256 (x), uint256 (y));
if (negativeResult) {
require (absoluteResult <= 0x80000000000000000000000000000000);
return -int128 (absoluteResult); // We rely on overflow behavior here
} else {
require (absoluteResult <= 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF);
return int128 (absoluteResult); // We rely on overflow behavior here
}
}
}
/**
* Calculate x / y rounding towards zero, where x and y are unsigned 256-bit
* integer numbers. Revert on overflow or when y is zero.
*
* @param x unsigned 256-bit integer number
* @param y unsigned 256-bit integer number
* @return signed 64.64-bit fixed point number
*/
function divu (uint256 x, uint256 y) internal pure returns (int128) {
unchecked {
require (y != 0);
uint128 result = divuu (x, y);
require (result <= uint128 (MAX_64x64));
return int128 (result);
}
}
/**
* Calculate -x. Revert on overflow.
*
* @param x signed 64.64-bit fixed point number
* @return signed 64.64-bit fixed point number
*/
function neg (int128 x) internal pure returns (int128) {
unchecked {
require (x != MIN_64x64);
return -x;
}
}
/**
* Calculate |x|. Revert on overflow.
*
* @param x signed 64.64-bit fixed point number
* @return signed 64.64-bit fixed point number
*/
function abs (int128 x) internal pure returns (int128) {
unchecked {
require (x != MIN_64x64);
return x < 0 ? -x : x;
}
}
/**
* Calculate 1 / x rounding towards zero. Revert on overflow or when x is
* zero.
*
* @param x signed 64.64-bit fixed point number
* @return signed 64.64-bit fixed point number
*/
function inv (int128 x) internal pure returns (int128) {
unchecked {
require (x != 0);
int256 result = int256 (0x100000000000000000000000000000000) / x;
require (result >= MIN_64x64 && result <= MAX_64x64);
return int128 (result);
}
}
/**
* Calculate arithmetics average of x and y, i.e. (x + y) / 2 rounding down.
*
* @param x signed 64.64-bit fixed point number
* @param y signed 64.64-bit fixed point number
* @return signed 64.64-bit fixed point number
*/
function avg (int128 x, int128 y) internal pure returns (int128) {
unchecked {
return int128 ((int256 (x) + int256 (y)) >> 1);
}
}
/**
* Calculate geometric average of x and y, i.e. sqrt (x * y) rounding down.
* Revert on overflow or in case x * y is negative.
*
* @param x signed 64.64-bit fixed point number
* @param y signed 64.64-bit fixed point number
* @return signed 64.64-bit fixed point number
*/
function gavg (int128 x, int128 y) internal pure returns (int128) {
unchecked {
int256 m = int256 (x) * int256 (y);
require (m >= 0);
require (m <
0x4000000000000000000000000000000000000000000000000000000000000000);
return int128 (sqrtu (uint256 (m)));
}
}
/**
* Calculate x^y assuming 0^0 is 1, where x is signed 64.64 fixed point number
* and y is unsigned 256-bit integer number. Revert on overflow.
*
* @param x signed 64.64-bit fixed point number
* @param y uint256 value
* @return signed 64.64-bit fixed point number
*/
function pow (int128 x, uint256 y) internal pure returns (int128) {
unchecked {
bool negative = x < 0 && y & 1 == 1;
uint256 absX = uint128 (x < 0 ? -x : x);
uint256 absResult;
absResult = 0x100000000000000000000000000000000;
if (absX <= 0x10000000000000000) {
absX <<= 63;
while (y != 0) {
if (y & 0x1 != 0) {
absResult = absResult * absX >> 127;
}
absX = absX * absX >> 127;
if (y & 0x2 != 0) {
absResult = absResult * absX >> 127;
}
absX = absX * absX >> 127;
if (y & 0x4 != 0) {
absResult = absResult * absX >> 127;
}
absX = absX * absX >> 127;
if (y & 0x8 != 0) {
absResult = absResult * absX >> 127;
}
absX = absX * absX >> 127;
y >>= 4;
}
absResult >>= 64;
} else {
uint256 absXShift = 63;
if (absX < 0x1000000000000000000000000) { absX <<= 32; absXShift -= 32; }
if (absX < 0x10000000000000000000000000000) { absX <<= 16; absXShift -= 16; }
if (absX < 0x1000000000000000000000000000000) { absX <<= 8; absXShift -= 8; }
if (absX < 0x10000000000000000000000000000000) { absX <<= 4; absXShift -= 4; }
if (absX < 0x40000000000000000000000000000000) { absX <<= 2; absXShift -= 2; }
if (absX < 0x80000000000000000000000000000000) { absX <<= 1; absXShift -= 1; }
uint256 resultShift = 0;
while (y != 0) {
require (absXShift < 64);
if (y & 0x1 != 0) {
absResult = absResult * absX >> 127;
resultShift += absXShift;
if (absResult > 0x100000000000000000000000000000000) {
absResult >>= 1;
resultShift += 1;
}
}
absX = absX * absX >> 127;
absXShift <<= 1;
if (absX >= 0x100000000000000000000000000000000) {
absX >>= 1;
absXShift += 1;
}
y >>= 1;
}
require (resultShift < 64);
absResult >>= 64 - resultShift;
}
int256 result = negative ? -int256 (absResult) : int256 (absResult);
require (result >= MIN_64x64 && result <= MAX_64x64);
return int128 (result);
}
}
/**
* Calculate sqrt (x) rounding down. Revert if x < 0.
*
* @param x signed 64.64-bit fixed point number
* @return signed 64.64-bit fixed point number
*/
function sqrt (int128 x) internal pure returns (int128) {
unchecked {
require (x >= 0);
return int128 (sqrtu (uint256 (int256 (x)) << 64));
}
}
/**
* Calculate binary logarithm of x. Revert if x <= 0.
*
* @param x signed 64.64-bit fixed point number
* @return signed 64.64-bit fixed point number
*/
function log_2 (int128 x) internal pure returns (int128) {
unchecked {
require (x > 0);
int256 msb = 0;
int256 xc = x;
if (xc >= 0x10000000000000000) { xc >>= 64; msb += 64; }
if (xc >= 0x100000000) { xc >>= 32; msb += 32; }
if (xc >= 0x10000) { xc >>= 16; msb += 16; }
if (xc >= 0x100) { xc >>= 8; msb += 8; }
if (xc >= 0x10) { xc >>= 4; msb += 4; }
if (xc >= 0x4) { xc >>= 2; msb += 2; }
if (xc >= 0x2) msb += 1; // No need to shift xc anymore
int256 result = msb - 64 << 64;
uint256 ux = uint256 (int256 (x)) << uint256 (127 - msb);
for (int256 bit = 0x8000000000000000; bit > 0; bit >>= 1) {
ux *= ux;
uint256 b = ux >> 255;
ux >>= 127 + b;
result += bit * int256 (b);
}
return int128 (result);
}
}
/**
* Calculate natural logarithm of x. Revert if x <= 0.
*
* @param x signed 64.64-bit fixed point number
* @return signed 64.64-bit fixed point number
*/
function ln (int128 x) internal pure returns (int128) {
unchecked {
require (x > 0);
return int128 (int256 (
uint256 (int256 (log_2 (x))) * 0xB17217F7D1CF79ABC9E3B39803F2F6AF >> 128));
}
}
/**
* Calculate binary exponent of x. Revert on overflow.
*
* @param x signed 64.64-bit fixed point number
* @return signed 64.64-bit fixed point number
*/
function exp_2 (int128 x) internal pure returns (int128) {
unchecked {
require (x < 0x400000000000000000); // Overflow
if (x < -0x400000000000000000) return 0; // Underflow
uint256 result = 0x80000000000000000000000000000000;
if (x & 0x8000000000000000 > 0)
result = result * 0x16A09E667F3BCC908B2FB1366EA957D3E >> 128;
if (x & 0x4000000000000000 > 0)
result = result * 0x1306FE0A31B7152DE8D5A46305C85EDEC >> 128;
if (x & 0x2000000000000000 > 0)
result = result * 0x1172B83C7D517ADCDF7C8C50EB14A791F >> 128;
if (x & 0x1000000000000000 > 0)
result = result * 0x10B5586CF9890F6298B92B71842A98363 >> 128;
if (x & 0x800000000000000 > 0)
result = result * 0x1059B0D31585743AE7C548EB68CA417FD >> 128;
if (x & 0x400000000000000 > 0)
result = result * 0x102C9A3E778060EE6F7CACA4F7A29BDE8 >> 128;
if (x & 0x200000000000000 > 0)
result = result * 0x10163DA9FB33356D84A66AE336DCDFA3F >> 128;
if (x & 0x100000000000000 > 0)
result = result * 0x100B1AFA5ABCBED6129AB13EC11DC9543 >> 128;
if (x & 0x80000000000000 > 0)
result = result * 0x10058C86DA1C09EA1FF19D294CF2F679B >> 128;
if (x & 0x40000000000000 > 0)
result = result * 0x1002C605E2E8CEC506D21BFC89A23A00F >> 128;
if (x & 0x20000000000000 > 0)
result = result * 0x100162F3904051FA128BCA9C55C31E5DF >> 128;
if (x & 0x10000000000000 > 0)
result = result * 0x1000B175EFFDC76BA38E31671CA939725 >> 128;
if (x & 0x8000000000000 > 0)
result = result * 0x100058BA01FB9F96D6CACD4B180917C3D >> 128;
if (x & 0x4000000000000 > 0)
result = result * 0x10002C5CC37DA9491D0985C348C68E7B3 >> 128;
if (x & 0x2000000000000 > 0)
result = result * 0x1000162E525EE054754457D5995292026 >> 128;
if (x & 0x1000000000000 > 0)
result = result * 0x10000B17255775C040618BF4A4ADE83FC >> 128;
if (x & 0x800000000000 > 0)
result = result * 0x1000058B91B5BC9AE2EED81E9B7D4CFAB >> 128;
if (x & 0x400000000000 > 0)
result = result * 0x100002C5C89D5EC6CA4D7C8ACC017B7C9 >> 128;
if (x & 0x200000000000 > 0)
result = result * 0x10000162E43F4F831060E02D839A9D16D >> 128;
if (x & 0x100000000000 > 0)
result = result * 0x100000B1721BCFC99D9F890EA06911763 >> 128;
if (x & 0x80000000000 > 0)
result = result * 0x10000058B90CF1E6D97F9CA14DBCC1628 >> 128;
if (x & 0x40000000000 > 0)
result = result * 0x1000002C5C863B73F016468F6BAC5CA2B >> 128;
if (x & 0x20000000000 > 0)
result = result * 0x100000162E430E5A18F6119E3C02282A5 >> 128;
if (x & 0x10000000000 > 0)
result = result * 0x1000000B1721835514B86E6D96EFD1BFE >> 128;
if (x & 0x8000000000 > 0)
result = result * 0x100000058B90C0B48C6BE5DF846C5B2EF >> 128;
if (x & 0x4000000000 > 0)
result = result * 0x10000002C5C8601CC6B9E94213C72737A >> 128;
if (x & 0x2000000000 > 0)
result = result * 0x1000000162E42FFF037DF38AA2B219F06 >> 128;
if (x & 0x1000000000 > 0)
result = result * 0x10000000B17217FBA9C739AA5819F44F9 >> 128;
if (x & 0x800000000 > 0)
result = result * 0x1000000058B90BFCDEE5ACD3C1CEDC823 >> 128;
if (x & 0x400000000 > 0)
result = result * 0x100000002C5C85FE31F35A6A30DA1BE50 >> 128;
if (x & 0x200000000 > 0)
result = result * 0x10000000162E42FF0999CE3541B9FFFCF >> 128;
if (x & 0x100000000 > 0)
result = result * 0x100000000B17217F80F4EF5AADDA45554 >> 128;
if (x & 0x80000000 > 0)
result = result * 0x10000000058B90BFBF8479BD5A81B51AD >> 128;
if (x & 0x40000000 > 0)
result = result * 0x1000000002C5C85FDF84BD62AE30A74CC >> 128;
if (x & 0x20000000 > 0)
result = result * 0x100000000162E42FEFB2FED257559BDAA >> 128;
if (x & 0x10000000 > 0)
result = result * 0x1000000000B17217F7D5A7716BBA4A9AE >> 128;
if (x & 0x8000000 > 0)
result = result * 0x100000000058B90BFBE9DDBAC5E109CCE >> 128;
if (x & 0x4000000 > 0)
result = result * 0x10000000002C5C85FDF4B15DE6F17EB0D >> 128;
if (x & 0x2000000 > 0)
result = result * 0x1000000000162E42FEFA494F1478FDE05 >> 128;
if (x & 0x1000000 > 0)
result = result * 0x10000000000B17217F7D20CF927C8E94C >> 128;
if (x & 0x800000 > 0)
result = result * 0x1000000000058B90BFBE8F71CB4E4B33D >> 128;
if (x & 0x400000 > 0)
result = result * 0x100000000002C5C85FDF477B662B26945 >> 128;
if (x & 0x200000 > 0)
result = result * 0x10000000000162E42FEFA3AE53369388C >> 128;
if (x & 0x100000 > 0)
result = result * 0x100000000000B17217F7D1D351A389D40 >> 128;
if (x & 0x80000 > 0)
result = result * 0x10000000000058B90BFBE8E8B2D3D4EDE >> 128;
if (x & 0x40000 > 0)
result = result * 0x1000000000002C5C85FDF4741BEA6E77E >> 128;
if (x & 0x20000 > 0)
result = result * 0x100000000000162E42FEFA39FE95583C2 >> 128;
if (x & 0x10000 > 0)
result = result * 0x1000000000000B17217F7D1CFB72B45E1 >> 128;
if (x & 0x8000 > 0)
result = result * 0x100000000000058B90BFBE8E7CC35C3F0 >> 128;
if (x & 0x4000 > 0)
result = result * 0x10000000000002C5C85FDF473E242EA38 >> 128;
if (x & 0x2000 > 0)
result = result * 0x1000000000000162E42FEFA39F02B772C >> 128;
if (x & 0x1000 > 0)
result = result * 0x10000000000000B17217F7D1CF7D83C1A >> 128;
if (x & 0x800 > 0)
result = result * 0x1000000000000058B90BFBE8E7BDCBE2E >> 128;
if (x & 0x400 > 0)
result = result * 0x100000000000002C5C85FDF473DEA871F >> 128;
if (x & 0x200 > 0)
result = result * 0x10000000000000162E42FEFA39EF44D91 >> 128;
if (x & 0x100 > 0)
result = result * 0x100000000000000B17217F7D1CF79E949 >> 128;
if (x & 0x80 > 0)
result = result * 0x10000000000000058B90BFBE8E7BCE544 >> 128;
if (x & 0x40 > 0)
result = result * 0x1000000000000002C5C85FDF473DE6ECA >> 128;
if (x & 0x20 > 0)
result = result * 0x100000000000000162E42FEFA39EF366F >> 128;
if (x & 0x10 > 0)
result = result * 0x1000000000000000B17217F7D1CF79AFA >> 128;
if (x & 0x8 > 0)
result = result * 0x100000000000000058B90BFBE8E7BCD6D >> 128;
if (x & 0x4 > 0)
result = result * 0x10000000000000002C5C85FDF473DE6B2 >> 128;
if (x & 0x2 > 0)
result = result * 0x1000000000000000162E42FEFA39EF358 >> 128;
if (x & 0x1 > 0)
result = result * 0x10000000000000000B17217F7D1CF79AB >> 128;
result >>= uint256 (int256 (63 - (x >> 64)));
require (result <= uint256 (int256 (MAX_64x64)));
return int128 (int256 (result));
}
}
/**
* Calculate natural exponent of x. Revert on overflow.
*
* @param x signed 64.64-bit fixed point number
* @return signed 64.64-bit fixed point number
*/
function exp (int128 x) internal pure returns (int128) {
unchecked {
require (x < 0x400000000000000000); // Overflow
if (x < -0x400000000000000000) return 0; // Underflow
return exp_2 (
int128 (int256 (x) * 0x171547652B82FE1777D0FFDA0D23A7D12 >> 128));
}
}
/**
* Calculate x / y rounding towards zero, where x and y are unsigned 256-bit
* integer numbers. Revert on overflow or when y is zero.
*
* @param x unsigned 256-bit integer number
* @param y unsigned 256-bit integer number
* @return unsigned 64.64-bit fixed point number
*/
function divuu (uint256 x, uint256 y) private pure returns (uint128) {
unchecked {
require (y != 0);
uint256 result;
if (x <= 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)
result = (x << 64) / y;
else {
uint256 msb = 192;
uint256 xc = x >> 192;
if (xc >= 0x100000000) { xc >>= 32; msb += 32; }
if (xc >= 0x10000) { xc >>= 16; msb += 16; }
if (xc >= 0x100) { xc >>= 8; msb += 8; }
if (xc >= 0x10) { xc >>= 4; msb += 4; }
if (xc >= 0x4) { xc >>= 2; msb += 2; }
if (xc >= 0x2) msb += 1; // No need to shift xc anymore
result = (x << 255 - msb) / ((y - 1 >> msb - 191) + 1);
require (result <= 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF);
uint256 hi = result * (y >> 128);
uint256 lo = result * (y & 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF);
uint256 xh = x >> 192;
uint256 xl = x << 64;
if (xl < lo) xh -= 1;
xl -= lo; // We rely on overflow behavior here
lo = hi << 128;
if (xl < lo) xh -= 1;
xl -= lo; // We rely on overflow behavior here
result += xh == hi >> 128 ? xl / y : 1;
}
require (result <= 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF);
return uint128 (result);
}
}
/**
* Calculate sqrt (x) rounding down, where x is unsigned 256-bit integer
* number.
*
* @param x unsigned 256-bit integer number
* @return unsigned 128-bit integer number
*/
function sqrtu (uint256 x) private pure returns (uint128) {
unchecked {
if (x == 0) return 0;
else {
uint256 xx = x;
uint256 r = 1;
if (xx >= 0x100000000000000000000000000000000) { xx >>= 128; r <<= 64; }
if (xx >= 0x10000000000000000) { xx >>= 64; r <<= 32; }
if (xx >= 0x100000000) { xx >>= 32; r <<= 16; }
if (xx >= 0x10000) { xx >>= 16; r <<= 8; }
if (xx >= 0x100) { xx >>= 8; r <<= 4; }
if (xx >= 0x10) { xx >>= 4; r <<= 2; }
if (xx >= 0x4) { r <<= 1; }
r = (r + x / r) >> 1;
r = (r + x / r) >> 1;
r = (r + x / r) >> 1;
r = (r + x / r) >> 1;
r = (r + x / r) >> 1;
r = (r + x / r) >> 1;
r = (r + x / r) >> 1; // Seven iterations should be enough
uint256 r1 = x / r;
return uint128 (r < r1 ? r : r1);
}
}
}
}
pragma solidity >=0.5.0;
interface IUniswapV2Pair {
event Approval(address indexed owner, address indexed spender, uint value);
event Transfer(address indexed from, address indexed to, uint value);
function name() external pure returns (string memory);
function symbol() external pure returns (string memory);
function decimals() external pure returns (uint8);
function totalSupply() external view returns (uint);
function balanceOf(address owner) external view returns (uint);
function allowance(address owner, address spender) external view returns (uint);
function approve(address spender, uint value) external returns (bool);
function transfer(address to, uint value) external returns (bool);
function transferFrom(address from, address to, uint value) external returns (bool);
function DOMAIN_SEPARATOR() external view returns (bytes32);
function PERMIT_TYPEHASH() external pure returns (bytes32);
function nonces(address owner) external view returns (uint);
function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
event Mint(address indexed sender, uint amount0, uint amount1);
event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
event Swap(
address indexed sender,
uint amount0In,
uint amount1In,
uint amount0Out,
uint amount1Out,
address indexed to
);
event Sync(uint112 reserve0, uint112 reserve1);
function MINIMUM_LIQUIDITY() external pure returns (uint);
function factory() external view returns (address);
function token0() external view returns (address);
function token1() external view returns (address);
function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
function price0CumulativeLast() external view returns (uint);
function price1CumulativeLast() external view returns (uint);
function kLast() external view returns (uint);
function mint(address to) external returns (uint liquidity);
function burn(address to) external returns (uint amount0, uint amount1);
function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
function skim(address to) external;
function sync() external;
function initialize(address, address) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/structs/EnumerableSet.sol)
// This file was procedurally generated from scripts/generate/templates/EnumerableSet.js.
pragma solidity ^0.8.0;
/**
* @dev Library for managing
* https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
* types.
*
* Sets have the following properties:
*
* - Elements are added, removed, and checked for existence in constant time
* (O(1)).
* - Elements are enumerated in O(n). No guarantees are made on the ordering.
*
* ```solidity
* contract Example {
* // Add the library methods
* using EnumerableSet for EnumerableSet.AddressSet;
*
* // Declare a set state variable
* EnumerableSet.AddressSet private mySet;
* }
* ```
*
* As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
* and `uint256` (`UintSet`) are supported.
*
* [WARNING]
* ====
* Trying to delete such a structure from storage will likely result in data corruption, rendering the structure
* unusable.
* See https://github.com/ethereum/solidity/pull/11843[ethereum/solidity#11843] for more info.
*
* In order to clean an EnumerableSet, you can either remove all elements one by one or create a fresh instance using an
* array of EnumerableSet.
* ====
*/
library EnumerableSet {
// To implement this library for multiple types with as little code
// repetition as possible, we write it in terms of a generic Set type with
// bytes32 values.
// The Set implementation uses private functions, and user-facing
// implementations (such as AddressSet) are just wrappers around the
// underlying Set.
// This means that we can only create new EnumerableSets for types that fit
// in bytes32.
struct Set {
// Storage of set values
bytes32[] _values;
// Position of the value in the `values` array, plus 1 because index 0
// means a value is not in the set.
mapping(bytes32 => uint256) _indexes;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function _add(Set storage set, bytes32 value) private returns (bool) {
if (!_contains(set, value)) {
set._values.push(value);
// The value is stored at length-1, but we add 1 to all indexes
// and use 0 as a sentinel value
set._indexes[value] = set._values.length;
return true;
} else {
return false;
}
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function _remove(Set storage set, bytes32 value) private returns (bool) {
// We read and store the value's index to prevent multiple reads from the same storage slot
uint256 valueIndex = set._indexes[value];
if (valueIndex != 0) {
// Equivalent to contains(set, value)
// To delete an element from the _values array in O(1), we swap the element to delete with the last one in
// the array, and then remove the last element (sometimes called as 'swap and pop').
// This modifies the order of the array, as noted in {at}.
uint256 toDeleteIndex = valueIndex - 1;
uint256 lastIndex = set._values.length - 1;
if (lastIndex != toDeleteIndex) {
bytes32 lastValue = set._values[lastIndex];
// Move the last value to the index where the value to delete is
set._values[toDeleteIndex] = lastValue;
// Update the index for the moved value
set._indexes[lastValue] = valueIndex; // Replace lastValue's index to valueIndex
}
// Delete the slot where the moved value was stored
set._values.pop();
// Delete the index for the deleted slot
delete set._indexes[value];
return true;
} else {
return false;
}
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function _contains(Set storage set, bytes32 value) private view returns (bool) {
return set._indexes[value] != 0;
}
/**
* @dev Returns the number of values on the set. O(1).
*/
function _length(Set storage set) private view returns (uint256) {
return set._values.length;
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function _at(Set storage set, uint256 index) private view returns (bytes32) {
return set._values[index];
}
/**
* @dev Return the entire set in an array
*
* WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
* to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
* this function has an unbounded cost, and using it as part of a state-changing function may render the function
* uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
*/
function _values(Set storage set) private view returns (bytes32[] memory) {
return set._values;
}
// Bytes32Set
struct Bytes32Set {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
return _add(set._inner, value);
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
return _remove(set._inner, value);
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
return _contains(set._inner, value);
}
/**
* @dev Returns the number of values in the set. O(1).
*/
function length(Bytes32Set storage set) internal view returns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
return _at(set._inner, index);
}
/**
* @dev Return the entire set in an array
*
* WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
* to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
* this function has an unbounded cost, and using it as part of a state-changing function may render the function
* uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
*/
function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
bytes32[] memory store = _values(set._inner);
bytes32[] memory result;
/// @solidity memory-safe-assembly
assembly {
result := store
}
return result;
}
// AddressSet
struct AddressSet {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function add(AddressSet storage set, address value) internal returns (bool) {
return _add(set._inner, bytes32(uint256(uint160(value))));
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function remove(AddressSet storage set, address value) internal returns (bool) {
return _remove(set._inner, bytes32(uint256(uint160(value))));
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function contains(AddressSet storage set, address value) internal view returns (bool) {
return _contains(set._inner, bytes32(uint256(uint160(value))));
}
/**
* @dev Returns the number of values in the set. O(1).
*/
function length(AddressSet storage set) internal view returns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function at(AddressSet storage set, uint256 index) internal view returns (address) {
return address(uint160(uint256(_at(set._inner, index))));
}
/**
* @dev Return the entire set in an array
*
* WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
* to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
* this function has an unbounded cost, and using it as part of a state-changing function may render the function
* uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
*/
function values(AddressSet storage set) internal view returns (address[] memory) {
bytes32[] memory store = _values(set._inner);
address[] memory result;
/// @solidity memory-safe-assembly
assembly {
result := store
}
return result;
}
// UintSet
struct UintSet {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function add(UintSet storage set, uint256 value) internal returns (bool) {
return _add(set._inner, bytes32(value));
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function remove(UintSet storage set, uint256 value) internal returns (bool) {
return _remove(set._inner, bytes32(value));
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function contains(UintSet storage set, uint256 value) internal view returns (bool) {
return _contains(set._inner, bytes32(value));
}
/**
* @dev Returns the number of values in the set. O(1).
*/
function length(UintSet storage set) internal view returns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function at(UintSet storage set, uint256 index) internal view returns (uint256) {
return uint256(_at(set._inner, index));
}
/**
* @dev Return the entire set in an array
*
* WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
* to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
* this function has an unbounded cost, and using it as part of a state-changing function may render the function
* uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
*/
function values(UintSet storage set) internal view returns (uint256[] memory) {
bytes32[] memory store = _values(set._inner);
uint256[] memory result;
/// @solidity memory-safe-assembly
assembly {
result := store
}
return result;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/math/SignedMath.sol)
pragma solidity ^0.8.0;
/**
* @dev Standard signed math utilities missing in the Solidity language.
*/
library SignedMath {
/**
* @dev Returns the largest of two signed numbers.
*/
function max(int256 a, int256 b) internal pure returns (int256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two signed numbers.
*/
function min(int256 a, int256 b) internal pure returns (int256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two signed numbers without overflow.
* The result is rounded towards zero.
*/
function average(int256 a, int256 b) internal pure returns (int256) {
// Formula from the book "Hacker's Delight"
int256 x = (a & b) + ((a ^ b) >> 1);
return x + (int256(uint256(x) >> 255) & (a ^ b));
}
/**
* @dev Returns the absolute unsigned value of a signed value.
*/
function abs(int256 n) internal pure returns (uint256) {
unchecked {
// must be unchecked in order to support `n = type(int256).min`
return uint256(n >= 0 ? n : -n);
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/math/Math.sol)
pragma solidity ^0.8.0;
/**
* @dev Standard math utilities missing in the Solidity language.
*/
library Math {
enum Rounding {
Down, // Toward negative infinity
Up, // Toward infinity
Zero // Toward zero
}
/**
* @dev Returns the largest of two numbers.
*/
function max(uint256 a, uint256 b) internal pure returns (uint256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two numbers.
*/
function min(uint256 a, uint256 b) internal pure returns (uint256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two numbers. The result is rounded towards
* zero.
*/
function average(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b) / 2 can overflow.
return (a & b) + (a ^ b) / 2;
}
/**
* @dev Returns the ceiling of the division of two numbers.
*
* This differs from standard division with `/` in that it rounds up instead
* of rounding down.
*/
function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b - 1) / b can overflow on addition, so we distribute.
return a == 0 ? 0 : (a - 1) / b + 1;
}
/**
* @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
* @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
* with further edits by Uniswap Labs also under MIT license.
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
unchecked {
// 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
// use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
// variables such that product = prod1 * 2^256 + prod0.
uint256 prod0; // Least significant 256 bits of the product
uint256 prod1; // Most significant 256 bits of the product
assembly {
let mm := mulmod(x, y, not(0))
prod0 := mul(x, y)
prod1 := sub(sub(mm, prod0), lt(mm, prod0))
}
// Handle non-overflow cases, 256 by 256 division.
if (prod1 == 0) {
// Solidity will revert if denominator == 0, unlike the div opcode on its own.
// The surrounding unchecked block does not change this fact.
// See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
return prod0 / denominator;
}
// Make sure the result is less than 2^256. Also prevents denominator == 0.
require(denominator > prod1, "Math: mulDiv overflow");
///////////////////////////////////////////////
// 512 by 256 division.
///////////////////////////////////////////////
// Make division exact by subtracting the remainder from [prod1 prod0].
uint256 remainder;
assembly {
// Compute remainder using mulmod.
remainder := mulmod(x, y, denominator)
// Subtract 256 bit number from 512 bit number.
prod1 := sub(prod1, gt(remainder, prod0))
prod0 := sub(prod0, remainder)
}
// Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
// See https://cs.stackexchange.com/q/138556/92363.
// Does not overflow because the denominator cannot be zero at this stage in the function.
uint256 twos = denominator & (~denominator + 1);
assembly {
// Divide denominator by twos.
denominator := div(denominator, twos)
// Divide [prod1 prod0] by twos.
prod0 := div(prod0, twos)
// Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
twos := add(div(sub(0, twos), twos), 1)
}
// Shift in bits from prod1 into prod0.
prod0 |= prod1 * twos;
// Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
// that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
// four bits. That is, denominator * inv = 1 mod 2^4.
uint256 inverse = (3 * denominator) ^ 2;
// Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
// in modular arithmetic, doubling the correct bits in each step.
inverse *= 2 - denominator * inverse; // inverse mod 2^8
inverse *= 2 - denominator * inverse; // inverse mod 2^16
inverse *= 2 - denominator * inverse; // inverse mod 2^32
inverse *= 2 - denominator * inverse; // inverse mod 2^64
inverse *= 2 - denominator * inverse; // inverse mod 2^128
inverse *= 2 - denominator * inverse; // inverse mod 2^256
// Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
// This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
// less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
// is no longer required.
result = prod0 * inverse;
return result;
}
}
/**
* @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
uint256 result = mulDiv(x, y, denominator);
if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
result += 1;
}
return result;
}
/**
* @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
*
* Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
*/
function sqrt(uint256 a) internal pure returns (uint256) {
if (a == 0) {
return 0;
}
// For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
//
// We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
// `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
//
// This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
// → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
// → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
//
// Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
uint256 result = 1 << (log2(a) >> 1);
// At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
// since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
// every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
// into the expected uint128 result.
unchecked {
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
return min(result, a / result);
}
}
/**
* @notice Calculates sqrt(a), following the selected rounding direction.
*/
function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = sqrt(a);
return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
}
}
/**
* @dev Return the log in base 2, rounded down, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 128;
}
if (value >> 64 > 0) {
value >>= 64;
result += 64;
}
if (value >> 32 > 0) {
value >>= 32;
result += 32;
}
if (value >> 16 > 0) {
value >>= 16;
result += 16;
}
if (value >> 8 > 0) {
value >>= 8;
result += 8;
}
if (value >> 4 > 0) {
value >>= 4;
result += 4;
}
if (value >> 2 > 0) {
value >>= 2;
result += 2;
}
if (value >> 1 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 2, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log2(value);
return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 10, rounded down, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >= 10 ** 64) {
value /= 10 ** 64;
result += 64;
}
if (value >= 10 ** 32) {
value /= 10 ** 32;
result += 32;
}
if (value >= 10 ** 16) {
value /= 10 ** 16;
result += 16;
}
if (value >= 10 ** 8) {
value /= 10 ** 8;
result += 8;
}
if (value >= 10 ** 4) {
value /= 10 ** 4;
result += 4;
}
if (value >= 10 ** 2) {
value /= 10 ** 2;
result += 2;
}
if (value >= 10 ** 1) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 10, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log10(value);
return result + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 256, rounded down, of a positive value.
* Returns 0 if given 0.
*
* Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
*/
function log256(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 16;
}
if (value >> 64 > 0) {
value >>= 64;
result += 8;
}
if (value >> 32 > 0) {
value >>= 32;
result += 4;
}
if (value >> 16 > 0) {
value >>= 16;
result += 2;
}
if (value >> 8 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 256, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log256(value);
return result + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0);
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/
interface IERC165 {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
pragma solidity ^0.8.0;
import "./IERC165.sol";
/**
* @dev Implementation of the {IERC165} interface.
*
* Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
* for the additional interface id that will be supported. For example:
*
* ```solidity
* function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
* return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
* }
* ```
*
* Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
*/
abstract contract ERC165 is IERC165 {
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IERC165).interfaceId;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/Strings.sol)
pragma solidity ^0.8.0;
import "./math/Math.sol";
import "./math/SignedMath.sol";
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant _SYMBOLS = "0123456789abcdef";
uint8 private constant _ADDRESS_LENGTH = 20;
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/
function toString(uint256 value) internal pure returns (string memory) {
unchecked {
uint256 length = Math.log10(value) + 1;
string memory buffer = new string(length);
uint256 ptr;
/// @solidity memory-safe-assembly
assembly {
ptr := add(buffer, add(32, length))
}
while (true) {
ptr--;
/// @solidity memory-safe-assembly
assembly {
mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
}
value /= 10;
if (value == 0) break;
}
return buffer;
}
}
/**
* @dev Converts a `int256` to its ASCII `string` decimal representation.
*/
function toString(int256 value) internal pure returns (string memory) {
return string(abi.encodePacked(value < 0 ? "-" : "", toString(SignedMath.abs(value))));
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/
function toHexString(uint256 value) internal pure returns (string memory) {
unchecked {
return toHexString(value, Math.log256(value) + 1);
}
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
*/
function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
bytes memory buffer = new bytes(2 * length + 2);
buffer[0] = "0";
buffer[1] = "x";
for (uint256 i = 2 * length + 1; i > 1; --i) {
buffer[i] = _SYMBOLS[value & 0xf];
value >>= 4;
}
require(value == 0, "Strings: hex length insufficient");
return string(buffer);
}
/**
* @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
*/
function toHexString(address addr) internal pure returns (string memory) {
return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
}
/**
* @dev Returns true if the two strings are equal.
*/
function equal(string memory a, string memory b) internal pure returns (bool) {
return keccak256(bytes(a)) == keccak256(bytes(b));
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.4) (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;
}
function _contextSuffixLength() internal view virtual returns (uint256) {
return 0;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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
*
* Furthermore, `isContract` will also return true if the target contract within
* the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
* which only has an effect at the end of a transaction.
* ====
*
* [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://consensys.net/diligence/blog/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/v0.8.0/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);
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.3) (token/ERC20/utils/SafeERC20.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
import "../extensions/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;
/**
* @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
* non-reverting calls are assumed to be successful.
*/
function safeTransfer(IERC20 token, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
/**
* @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
* calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
*/
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));
}
/**
* @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful.
*/
function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 oldAllowance = token.allowance(address(this), spender);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
}
/**
* @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful.
*/
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");
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
}
}
/**
* @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
* to be set to zero before setting it to a non-zero value, such as USDT.
*/
function forceApprove(IERC20 token, address spender, uint256 value) internal {
bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value);
if (!_callOptionalReturnBool(token, approvalCall)) {
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0));
_callOptionalReturn(token, approvalCall);
}
}
/**
* @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
* Revert on invalid signature.
*/
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");
require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation 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).
*
* This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
*/
function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
// 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 cannot use {Address-functionCall} here since this should return false
// and not revert is the subcall reverts.
(bool success, bytes memory returndata) = address(token).call(data);
return
success && (returndata.length == 0 || abi.decode(returndata, (bool))) && Address.isContract(address(token));
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.4) (token/ERC20/extensions/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.
*
* ==== Security Considerations
*
* There are two important considerations concerning the use of `permit`. The first is that a valid permit signature
* expresses an allowance, and it should not be assumed to convey additional meaning. In particular, it should not be
* considered as an intention to spend the allowance in any specific way. The second is that because permits have
* built-in replay protection and can be submitted by anyone, they can be frontrun. A protocol that uses permits should
* take this into consideration and allow a `permit` call to fail. Combining these two aspects, a pattern that may be
* generally recommended is:
*
* ```solidity
* function doThingWithPermit(..., uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public {
* try token.permit(msg.sender, address(this), value, deadline, v, r, s) {} catch {}
* doThing(..., value);
* }
*
* function doThing(..., uint256 value) public {
* token.safeTransferFrom(msg.sender, address(this), value);
* ...
* }
* ```
*
* Observe that: 1) `msg.sender` is used as the owner, leaving no ambiguity as to the signer intent, and 2) the use of
* `try/catch` allows the permit to fail and makes the code tolerant to frontrunning. (See also
* {SafeERC20-safeTransferFrom}).
*
* Additionally, note that smart contract wallets (such as Argent or Safe) are not able to produce permit signatures, so
* contracts should have entry points that don't rely on permit.
*/
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].
*
* CAUTION: See Security Considerations above.
*/
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 v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/
interface IERC20Metadata is IERC20 {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);
/**
* @dev Returns the symbol of the token.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the decimals places of the token.
*/
function decimals() external view returns (uint8);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/extensions/ERC20Burnable.sol)
pragma solidity ^0.8.0;
import "../ERC20.sol";
import "../../../utils/Context.sol";
/**
* @dev Extension of {ERC20} that allows token holders to destroy both their own
* tokens and those that they have an allowance for, in a way that can be
* recognized off-chain (via event analysis).
*/
abstract contract ERC20Burnable is Context, ERC20 {
/**
* @dev Destroys `amount` tokens from the caller.
*
* See {ERC20-_burn}.
*/
function burn(uint256 amount) public virtual {
_burn(_msgSender(), amount);
}
/**
* @dev Destroys `amount` tokens from `account`, deducting from the caller's
* allowance.
*
* See {ERC20-_burn} and {ERC20-allowance}.
*
* Requirements:
*
* - the caller must have allowance for ``accounts``'s tokens of at least
* `amount`.
*/
function burnFrom(address account, uint256 amount) public virtual {
_spendAllowance(account, _msgSender(), amount);
_burn(account, amount);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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 (last updated v4.9.0) (token/ERC20/ERC20.sol)
pragma solidity ^0.8.0;
import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20PresetMinterPauser}.
*
* TIP: For a detailed writeup see our guide
* https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* The default value of {decimals} is 18. To change this, you should override
* this function so it returns a different value.
*
* We have followed general OpenZeppelin Contracts guidelines: functions revert
* instead returning `false` on failure. This behavior is nonetheless
* conventional and does not conflict with the expectations of ERC20
* applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/
contract ERC20 is Context, IERC20, IERC20Metadata {
mapping(address => uint256) private _balances;
mapping(address => mapping(address => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
/**
* @dev Sets the values for {name} and {symbol}.
*
* All two of these values are immutable: they can only be set once during
* construction.
*/
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev Returns the name of the token.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5.05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the default value returned by this function, unless
* it's overridden.
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
function decimals() public view virtual override returns (uint8) {
return 18;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address to, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_transfer(owner, to, 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}.
*
* NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
* `transferFrom`. This is semantically equivalent to an infinite approval.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_approve(owner, 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}.
*
* NOTE: Does not update the allowance if the current allowance
* is the maximum `uint256`.
*
* Requirements:
*
* - `from` and `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
* - the caller must have allowance for ``from``'s tokens of at least
* `amount`.
*/
function transferFrom(address from, address to, uint256 amount) public virtual override returns (bool) {
address spender = _msgSender();
_spendAllowance(from, spender, amount);
_transfer(from, to, amount);
return true;
}
/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
address owner = _msgSender();
_approve(owner, spender, allowance(owner, spender) + addedValue);
return true;
}
/**
* @dev Atomically decreases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
address owner = _msgSender();
uint256 currentAllowance = allowance(owner, spender);
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
unchecked {
_approve(owner, spender, currentAllowance - subtractedValue);
}
return true;
}
/**
* @dev Moves `amount` of tokens from `from` to `to`.
*
* This internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
*/
function _transfer(address from, address to, uint256 amount) internal virtual {
require(from != address(0), "ERC20: transfer from the zero address");
require(to != address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(from, to, amount);
uint256 fromBalance = _balances[from];
require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
unchecked {
_balances[from] = fromBalance - amount;
// Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
// decrementing then incrementing.
_balances[to] += amount;
}
emit Transfer(from, to, amount);
_afterTokenTransfer(from, to, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address(0), account, amount);
_totalSupply += amount;
unchecked {
// Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
_balances[account] += amount;
}
emit Transfer(address(0), account, amount);
_afterTokenTransfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/
function _burn(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
uint256 accountBalance = _balances[account];
require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
unchecked {
_balances[account] = accountBalance - amount;
// Overflow not possible: amount <= accountBalance <= totalSupply.
_totalSupply -= amount;
}
emit Transfer(account, address(0), amount);
_afterTokenTransfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(address owner, address spender, uint256 amount) internal virtual {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Updates `owner` s allowance for `spender` based on spent `amount`.
*
* Does not update the allowance amount in case of infinite allowance.
* Revert if not enough allowance is available.
*
* Might emit an {Approval} event.
*/
function _spendAllowance(address owner, address spender, uint256 amount) internal virtual {
uint256 currentAllowance = allowance(owner, spender);
if (currentAllowance != type(uint256).max) {
require(currentAllowance >= amount, "ERC20: insufficient allowance");
unchecked {
_approve(owner, spender, currentAllowance - amount);
}
}
}
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual {}
/**
* @dev Hook that is called after any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* has been transferred to `to`.
* - when `from` is zero, `amount` tokens have been minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens have been burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _afterTokenTransfer(address from, address to, uint256 amount) internal virtual {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby disabling 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 v4.4.1 (access/IAccessControlEnumerable.sol)
pragma solidity ^0.8.0;
import "./IAccessControl.sol";
/**
* @dev External interface of AccessControlEnumerable declared to support ERC165 detection.
*/
interface IAccessControlEnumerable is IAccessControl {
/**
* @dev Returns one of the accounts that have `role`. `index` must be a
* value between 0 and {getRoleMemberCount}, non-inclusive.
*
* Role bearers are not sorted in any particular way, and their ordering may
* change at any point.
*
* WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
* you perform all queries on the same block. See the following
* https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
* for more information.
*/
function getRoleMember(bytes32 role, uint256 index) external view returns (address);
/**
* @dev Returns the number of accounts that have `role`. Can be used
* together with {getRoleMember} to enumerate all bearers of a role.
*/
function getRoleMemberCount(bytes32 role) external view returns (uint256);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)
pragma solidity ^0.8.0;
/**
* @dev External interface of AccessControl declared to support ERC165 detection.
*/
interface IAccessControl {
/**
* @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
*
* `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
* {RoleAdminChanged} not being emitted signaling this.
*
* _Available since v3.1._
*/
event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
/**
* @dev Emitted when `account` is granted `role`.
*
* `sender` is the account that originated the contract call, an admin role
* bearer except when using {AccessControl-_setupRole}.
*/
event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
/**
* @dev Emitted when `account` is revoked `role`.
*
* `sender` is the account that originated the contract call:
* - if using `revokeRole`, it is the admin role bearer
* - if using `renounceRole`, it is the role bearer (i.e. `account`)
*/
event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
/**
* @dev Returns `true` if `account` has been granted `role`.
*/
function hasRole(bytes32 role, address account) external view returns (bool);
/**
* @dev Returns the admin role that controls `role`. See {grantRole} and
* {revokeRole}.
*
* To change a role's admin, use {AccessControl-_setRoleAdmin}.
*/
function getRoleAdmin(bytes32 role) external view returns (bytes32);
/**
* @dev Grants `role` to `account`.
*
* If `account` had not been already granted `role`, emits a {RoleGranted}
* event.
*
* Requirements:
*
* - the caller must have ``role``'s admin role.
*/
function grantRole(bytes32 role, address account) external;
/**
* @dev Revokes `role` from `account`.
*
* If `account` had been granted `role`, emits a {RoleRevoked} event.
*
* Requirements:
*
* - the caller must have ``role``'s admin role.
*/
function revokeRole(bytes32 role, address account) external;
/**
* @dev Revokes `role` from the calling account.
*
* Roles are often managed via {grantRole} and {revokeRole}: this function's
* purpose is to provide a mechanism for accounts to lose their privileges
* if they are compromised (such as when a trusted device is misplaced).
*
* If the calling account had been granted `role`, emits a {RoleRevoked}
* event.
*
* Requirements:
*
* - the caller must be `account`.
*/
function renounceRole(bytes32 role, address account) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (access/AccessControlEnumerable.sol)
pragma solidity ^0.8.0;
import "./IAccessControlEnumerable.sol";
import "./AccessControl.sol";
import "../utils/structs/EnumerableSet.sol";
/**
* @dev Extension of {AccessControl} that allows enumerating the members of each role.
*/
abstract contract AccessControlEnumerable is IAccessControlEnumerable, AccessControl {
using EnumerableSet for EnumerableSet.AddressSet;
mapping(bytes32 => EnumerableSet.AddressSet) private _roleMembers;
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IAccessControlEnumerable).interfaceId || super.supportsInterface(interfaceId);
}
/**
* @dev Returns one of the accounts that have `role`. `index` must be a
* value between 0 and {getRoleMemberCount}, non-inclusive.
*
* Role bearers are not sorted in any particular way, and their ordering may
* change at any point.
*
* WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
* you perform all queries on the same block. See the following
* https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
* for more information.
*/
function getRoleMember(bytes32 role, uint256 index) public view virtual override returns (address) {
return _roleMembers[role].at(index);
}
/**
* @dev Returns the number of accounts that have `role`. Can be used
* together with {getRoleMember} to enumerate all bearers of a role.
*/
function getRoleMemberCount(bytes32 role) public view virtual override returns (uint256) {
return _roleMembers[role].length();
}
/**
* @dev Overload {_grantRole} to track enumerable memberships
*/
function _grantRole(bytes32 role, address account) internal virtual override {
super._grantRole(role, account);
_roleMembers[role].add(account);
}
/**
* @dev Overload {_revokeRole} to track enumerable memberships
*/
function _revokeRole(bytes32 role, address account) internal virtual override {
super._revokeRole(role, account);
_roleMembers[role].remove(account);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (access/AccessControl.sol)
pragma solidity ^0.8.0;
import "./IAccessControl.sol";
import "../utils/Context.sol";
import "../utils/Strings.sol";
import "../utils/introspection/ERC165.sol";
/**
* @dev Contract module that allows children to implement role-based access
* control mechanisms. This is a lightweight version that doesn't allow enumerating role
* members except through off-chain means by accessing the contract event logs. Some
* applications may benefit from on-chain enumerability, for those cases see
* {AccessControlEnumerable}.
*
* Roles are referred to by their `bytes32` identifier. These should be exposed
* in the external API and be unique. The best way to achieve this is by
* using `public constant` hash digests:
*
* ```solidity
* bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
* ```
*
* Roles can be used to represent a set of permissions. To restrict access to a
* function call, use {hasRole}:
*
* ```solidity
* function foo() public {
* require(hasRole(MY_ROLE, msg.sender));
* ...
* }
* ```
*
* Roles can be granted and revoked dynamically via the {grantRole} and
* {revokeRole} functions. Each role has an associated admin role, and only
* accounts that have a role's admin role can call {grantRole} and {revokeRole}.
*
* By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
* that only accounts with this role will be able to grant or revoke other
* roles. More complex role relationships can be created by using
* {_setRoleAdmin}.
*
* WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
* grant and revoke this role. Extra precautions should be taken to secure
* accounts that have been granted it. We recommend using {AccessControlDefaultAdminRules}
* to enforce additional security measures for this role.
*/
abstract contract AccessControl is Context, IAccessControl, ERC165 {
struct RoleData {
mapping(address => bool) members;
bytes32 adminRole;
}
mapping(bytes32 => RoleData) private _roles;
bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
/**
* @dev Modifier that checks that an account has a specific role. Reverts
* with a standardized message including the required role.
*
* The format of the revert reason is given by the following regular expression:
*
* /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
*
* _Available since v4.1._
*/
modifier onlyRole(bytes32 role) {
_checkRole(role);
_;
}
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId);
}
/**
* @dev Returns `true` if `account` has been granted `role`.
*/
function hasRole(bytes32 role, address account) public view virtual override returns (bool) {
return _roles[role].members[account];
}
/**
* @dev Revert with a standard message if `_msgSender()` is missing `role`.
* Overriding this function changes the behavior of the {onlyRole} modifier.
*
* Format of the revert message is described in {_checkRole}.
*
* _Available since v4.6._
*/
function _checkRole(bytes32 role) internal view virtual {
_checkRole(role, _msgSender());
}
/**
* @dev Revert with a standard message if `account` is missing `role`.
*
* The format of the revert reason is given by the following regular expression:
*
* /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
*/
function _checkRole(bytes32 role, address account) internal view virtual {
if (!hasRole(role, account)) {
revert(
string(
abi.encodePacked(
"AccessControl: account ",
Strings.toHexString(account),
" is missing role ",
Strings.toHexString(uint256(role), 32)
)
)
);
}
}
/**
* @dev Returns the admin role that controls `role`. See {grantRole} and
* {revokeRole}.
*
* To change a role's admin, use {_setRoleAdmin}.
*/
function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {
return _roles[role].adminRole;
}
/**
* @dev Grants `role` to `account`.
*
* If `account` had not been already granted `role`, emits a {RoleGranted}
* event.
*
* Requirements:
*
* - the caller must have ``role``'s admin role.
*
* May emit a {RoleGranted} event.
*/
function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
_grantRole(role, account);
}
/**
* @dev Revokes `role` from `account`.
*
* If `account` had been granted `role`, emits a {RoleRevoked} event.
*
* Requirements:
*
* - the caller must have ``role``'s admin role.
*
* May emit a {RoleRevoked} event.
*/
function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
_revokeRole(role, account);
}
/**
* @dev Revokes `role` from the calling account.
*
* Roles are often managed via {grantRole} and {revokeRole}: this function's
* purpose is to provide a mechanism for accounts to lose their privileges
* if they are compromised (such as when a trusted device is misplaced).
*
* If the calling account had been revoked `role`, emits a {RoleRevoked}
* event.
*
* Requirements:
*
* - the caller must be `account`.
*
* May emit a {RoleRevoked} event.
*/
function renounceRole(bytes32 role, address account) public virtual override {
require(account == _msgSender(), "AccessControl: can only renounce roles for self");
_revokeRole(role, account);
}
/**
* @dev Grants `role` to `account`.
*
* If `account` had not been already granted `role`, emits a {RoleGranted}
* event. Note that unlike {grantRole}, this function doesn't perform any
* checks on the calling account.
*
* May emit a {RoleGranted} event.
*
* [WARNING]
* ====
* This function should only be called from the constructor when setting
* up the initial roles for the system.
*
* Using this function in any other way is effectively circumventing the admin
* system imposed by {AccessControl}.
* ====
*
* NOTE: This function is deprecated in favor of {_grantRole}.
*/
function _setupRole(bytes32 role, address account) internal virtual {
_grantRole(role, account);
}
/**
* @dev Sets `adminRole` as ``role``'s admin role.
*
* Emits a {RoleAdminChanged} event.
*/
function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
bytes32 previousAdminRole = getRoleAdmin(role);
_roles[role].adminRole = adminRole;
emit RoleAdminChanged(role, previousAdminRole, adminRole);
}
/**
* @dev Grants `role` to `account`.
*
* Internal function without access restriction.
*
* May emit a {RoleGranted} event.
*/
function _grantRole(bytes32 role, address account) internal virtual {
if (!hasRole(role, account)) {
_roles[role].members[account] = true;
emit RoleGranted(role, account, _msgSender());
}
}
/**
* @dev Revokes `role` from `account`.
*
* Internal function without access restriction.
*
* May emit a {RoleRevoked} event.
*/
function _revokeRole(bytes32 role, address account) internal virtual {
if (hasRole(role, account)) {
_roles[role].members[account] = false;
emit RoleRevoked(role, account, _msgSender());
}
}
}