// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (access/AccessControl.sol)pragmasolidity ^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.
*/abstractcontractAccessControlisContext, IAccessControl, ERC165{
structRoleData {
mapping(address=>bool) members;
bytes32 adminRole;
}
mapping(bytes32=> RoleData) private _roles;
bytes32publicconstant 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})$/
*
* _Available since v4.1._
*/modifieronlyRole(bytes32 role) {
_checkRole(role);
_;
}
/**
* @dev See {IERC165-supportsInterface}.
*/functionsupportsInterface(bytes4 interfaceId) publicviewvirtualoverridereturns (bool) {
return interfaceId ==type(IAccessControl).interfaceId||super.supportsInterface(interfaceId);
}
/**
* @dev Returns `true` if `account` has been granted `role`.
*/functionhasRole(bytes32 role, address account) publicviewvirtualoverridereturns (bool) {
return _roles[role].members[account];
}
/**
* @dev Revert with a standard message if `_msgSender()` is missing `role`.
* Overriding this function changes the behavior of the {onlyRole} modifier.
*
* Format of the revert message is described in {_checkRole}.
*
* _Available since v4.6._
*/function_checkRole(bytes32 role) internalviewvirtual{
_checkRole(role, _msgSender());
}
/**
* @dev Revert with a standard message if `account` is missing `role`.
*
* The format of the revert reason is given by the following regular expression:
*
* /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
*/function_checkRole(bytes32 role, address account) internalviewvirtual{
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}.
*/functiongetRoleAdmin(bytes32 role) publicviewvirtualoverridereturns (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.
*/functiongrantRole(bytes32 role, address account) publicvirtualoverrideonlyRole(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.
*/functionrevokeRole(bytes32 role, address account) publicvirtualoverrideonlyRole(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.
*/functionrenounceRole(bytes32 role, address account) publicvirtualoverride{
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) internalvirtual{
_grantRole(role, account);
}
/**
* @dev Sets `adminRole` as ``role``'s admin role.
*
* Emits a {RoleAdminChanged} event.
*/function_setRoleAdmin(bytes32 role, bytes32 adminRole) internalvirtual{
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) internalvirtual{
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) internalvirtual{
if (hasRole(role, account)) {
_roles[role].members[account] =false;
emit RoleRevoked(role, account, _msgSender());
}
}
}
Contract Source Code
File 2 of 18: Context.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.4) (utils/Context.sol)pragmasolidity ^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.
*/abstractcontractContext{
function_msgSender() internalviewvirtualreturns (address) {
returnmsg.sender;
}
function_msgData() internalviewvirtualreturns (bytescalldata) {
returnmsg.data;
}
function_contextSuffixLength() internalviewvirtualreturns (uint256) {
return0;
}
}
Contract Source Code
File 3 of 18: ERC165.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)pragmasolidity ^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.
*/abstractcontractERC165isIERC165{
/**
* @dev See {IERC165-supportsInterface}.
*/functionsupportsInterface(bytes4 interfaceId) publicviewvirtualoverridereturns (bool) {
return interfaceId ==type(IERC165).interfaceId;
}
}
Contract Source Code
File 4 of 18: IAccessControl.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)pragmasolidity ^0.8.0;/**
* @dev External interface of AccessControl declared to support ERC165 detection.
*/interfaceIAccessControl{
/**
* @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._
*/eventRoleAdminChanged(bytes32indexed role, bytes32indexed previousAdminRole, bytes32indexed 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}.
*/eventRoleGranted(bytes32indexed role, addressindexed account, addressindexed 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`)
*/eventRoleRevoked(bytes32indexed role, addressindexed account, addressindexed sender);
/**
* @dev Returns `true` if `account` has been granted `role`.
*/functionhasRole(bytes32 role, address account) externalviewreturns (bool);
/**
* @dev Returns the admin role that controls `role`. See {grantRole} and
* {revokeRole}.
*
* To change a role's admin, use {AccessControl-_setRoleAdmin}.
*/functiongetRoleAdmin(bytes32 role) externalviewreturns (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.
*/functiongrantRole(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.
*/functionrevokeRole(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`.
*/functionrenounceRole(bytes32 role, address account) external;
}
Contract Source Code
File 5 of 18: IERC165.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)pragmasolidity ^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}.
*/interfaceIERC165{
/**
* @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.
*/functionsupportsInterface(bytes4 interfaceId) externalviewreturns (bool);
}
Contract Source Code
File 6 of 18: IERC20.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)pragmasolidity ^0.8.0;/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/interfaceIERC20{
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/eventTransfer(addressindexedfrom, addressindexed 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.
*/eventApproval(addressindexed owner, addressindexed spender, uint256 value);
/**
* @dev Returns the amount of tokens in existence.
*/functiontotalSupply() externalviewreturns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/functionbalanceOf(address account) externalviewreturns (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.
*/functiontransfer(address to, uint256 amount) externalreturns (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.
*/functionallowance(address owner, address spender) externalviewreturns (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.
*/functionapprove(address spender, uint256 amount) externalreturns (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.
*/functiontransferFrom(addressfrom, address to, uint256 amount) externalreturns (bool);
}
//SPDX-License-Identifier: Unlicensepragmasolidity ^0.8.0;import"@openzeppelin/contracts/utils/Context.sol";
import"@openzeppelin/contracts/token/ERC20/IERC20.sol";
import"../interfaces/ILosslessERC20.sol";
import"../interfaces/ILosslessController.sol";
contractLERC20isContext, ILERC20{
mapping (address=>uint256) private _balances;
mapping (address=>mapping (address=>uint256)) private _allowances;
uint256private _totalSupply;
stringprivate _name;
stringprivate _symbol;
addresspublic recoveryAdmin;
addressprivate recoveryAdminCandidate;
bytes32private recoveryAdminKeyHash;
addressoverridepublic admin;
uint256public timelockPeriod;
uint256public losslessTurnOffTimestamp;
boolpublic isLosslessOn =true;
ILssController public lossless;
constructor(stringmemory name_, stringmemory symbol_, address admin_, address recoveryAdmin_, uint256 timelockPeriod_, address lossless_) {
require(recoveryAdmin_ !=address(0), "LERC20: Recovery admin cannot be zero address");
require(admin_ !=address(0), "LERC20: Recovery admin cannot be zero address");
_name = name_;
_symbol = symbol_;
admin = admin_;
recoveryAdmin = recoveryAdmin_;
recoveryAdminCandidate =address(0);
recoveryAdminKeyHash ="";
require(timelockPeriod_ >2hours, "LERC20: Timelock period must be greater than 0");
require(timelockPeriod_ <2days, "LERC20: Timelock period must be less than 2 days");
// Note: should not be changed after deployment, due to potential security risk in case of loss of owner private key
timelockPeriod = timelockPeriod_;
losslessTurnOffTimestamp =0;
require(lossless_ !=address(0), "LERC20: Lossless cannot be zero address");
lossless = ILssController(lossless_);
}
// --- LOSSLESS modifiers ---modifierlssAprove(address spender, uint256 amount) {
if (isLosslessOn) {
lossless.beforeApprove(_msgSender(), spender, amount);
}
_;
}
modifierlssTransfer(address recipient, uint256 amount) {
if (isLosslessOn) {
lossless.beforeTransfer(_msgSender(), recipient, amount);
}
_;
}
modifierlssTransferFrom(address sender, address recipient, uint256 amount) {
if (isLosslessOn) {
lossless.beforeTransferFrom(_msgSender(),sender, recipient, amount);
}
_;
}
modifierlssIncreaseAllowance(address spender, uint256 addedValue) {
if (isLosslessOn) {
lossless.beforeIncreaseAllowance(_msgSender(), spender, addedValue);
}
_;
}
modifierlssDecreaseAllowance(address spender, uint256 subtractedValue) {
if (isLosslessOn) {
lossless.beforeDecreaseAllowance(_msgSender(), spender, subtractedValue);
}
_;
}
modifieronlyRecoveryAdmin() {
require(_msgSender() == recoveryAdmin, "LERC20: Must be recovery admin");
_;
}
// --- LOSSLESS management ---functiontransferOutBlacklistedFunds(address[] calldatafrom) overrideexternal{
require(_msgSender() ==address(lossless), "LERC20: Only lossless contract");
require(isLosslessOn, "LERC20: Lossless is off");
uint256 fromLength =from.length;
uint256 totalAmount =0;
for (uint256 i =0; i < fromLength; i++) {
address fromAddress =from[i];
uint256 fromBalance = _balances[fromAddress];
_balances[fromAddress] =0;
totalAmount += fromBalance;
emit Transfer(fromAddress, address(lossless), fromBalance);
}
_balances[address(lossless)] += totalAmount;
}
functionsetLosslessAdmin(address newAdmin) overrideexternalonlyRecoveryAdmin{
require(newAdmin != admin, "LERC20: Cannot set same address");
emit NewAdmin(newAdmin);
admin = newAdmin;
}
functiontransferRecoveryAdminOwnership(address candidate, bytes32 keyHash) overrideexternalonlyRecoveryAdmin{
require(candidate !=address(0), "LERC20: Candidate cannot be zero address");
recoveryAdminCandidate = candidate;
recoveryAdminKeyHash = keyHash;
emit NewRecoveryAdminProposal(candidate);
}
functionacceptRecoveryAdminOwnership(bytesmemory key) overrideexternal{
require(_msgSender() == recoveryAdminCandidate, "LERC20: Must be canditate");
require(keccak256(key) == recoveryAdminKeyHash, "LERC20: Invalid key");
emit NewRecoveryAdmin(recoveryAdminCandidate);
require(recoveryAdminCandidate !=address(0), "LERC20: Candidate cannot be zero address");
recoveryAdmin = recoveryAdminCandidate;
recoveryAdminCandidate =address(0);
recoveryAdminKeyHash ="";
}
functionproposeLosslessTurnOff() overrideexternalonlyRecoveryAdmin{
require(losslessTurnOffTimestamp ==0, "LERC20: TurnOff already proposed");
require(isLosslessOn, "LERC20: Lossless already off");
losslessTurnOffTimestamp =block.timestamp+ timelockPeriod;
emit LosslessTurnOffProposal(losslessTurnOffTimestamp);
}
functionexecuteLosslessTurnOff() overrideexternalonlyRecoveryAdmin{
require(losslessTurnOffTimestamp !=0, "ERC20: TurnOff not proposed");
require(losslessTurnOffTimestamp <=block.timestamp, "ERC20: Time lock in progress");
isLosslessOn =false;
losslessTurnOffTimestamp =0;
emit LosslessOff();
}
functionexecuteLosslessTurnOn() overrideexternalonlyRecoveryAdmin{
require(!isLosslessOn, "LERC20: Lossless already on");
losslessTurnOffTimestamp =0;
isLosslessOn =true;
emit LosslessOn();
}
functiongetAdmin() overridepublicviewvirtualreturns (address) {
return admin;
}
// --- ERC20 methods ---functionname() overridepublicviewvirtualreturns (stringmemory) {
return _name;
}
functionsymbol() overridepublicviewvirtualreturns (stringmemory) {
return _symbol;
}
functiondecimals() overridepublicviewvirtualreturns (uint8) {
return18;
}
functiontotalSupply() publicviewvirtualoverridereturns (uint256) {
return _totalSupply;
}
functionbalanceOf(address account) publicviewvirtualoverridereturns (uint256) {
return _balances[account];
}
functiontransfer(address recipient, uint256 amount) publicvirtualoverridelssTransfer(recipient, amount) returns (bool) {
_transfer(_msgSender(), recipient, amount);
returntrue;
}
functionallowance(address owner, address spender) publicviewvirtualoverridereturns (uint256) {
return _allowances[owner][spender];
}
functionapprove(address spender, uint256 amount) publicvirtualoverridelssAprove(spender, amount) returns (bool) {
_approve(_msgSender(), spender, amount);
returntrue;
}
functiontransferFrom(address sender, address recipient, uint256 amount) publicvirtualoverridelssTransferFrom(sender, recipient, amount) returns (bool) {
uint256 currentAllowance = _allowances[sender][_msgSender()];
require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
_transfer(sender, recipient, amount);
_approve(sender, _msgSender(), currentAllowance - amount);
returntrue;
}
functionincreaseAllowance(address spender, uint256 addedValue) overridepublicvirtuallssIncreaseAllowance(spender, addedValue) returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
returntrue;
}
functiondecreaseAllowance(address spender, uint256 subtractedValue) overridepublicvirtuallssDecreaseAllowance(spender, subtractedValue) returns (bool) {
uint256 currentAllowance = _allowances[_msgSender()][spender];
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
_approve(_msgSender(), spender, currentAllowance - subtractedValue);
returntrue;
}
function_transfer(address sender, address recipient, uint256 amount) internalvirtual{
require(sender !=address(0), "ERC20: transfer from the zero address");
require(recipient !=address(0), "ERC20: transfer to the zero address");
uint256 senderBalance = _balances[sender];
require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
_balances[sender] = senderBalance - amount;
_balances[recipient] += amount;
emit Transfer(sender, recipient, amount);
}
function_mint(address account, uint256 amount) internalvirtual{
require(account !=address(0), "ERC20: mint to the zero address");
_totalSupply += amount;
// Cannot overflow because the sum of all user// balances can't exceed the max uint256 value.unchecked {
_balances[account] += amount;
}
emit Transfer(address(0), account, amount);
}
function_burn(address account, uint256 amount) internalvirtual{
require(account !=address(0), "ERC20: burn from the zero address");
uint256 accountBalance = _balances[account];
require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
unchecked {
_balances[account] = accountBalance - amount;
}
_totalSupply -= amount;
emit Transfer(account, address(0), amount);
}
function_approve(address owner, address spender, uint256 amount) internalvirtual{
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
functionsupportsInterface(bytes4 interfaceId) publicviewvirtualreturns (bool) {
return interfaceId ==type(IERC20).interfaceId|| interfaceId ==type(ILERC20).interfaceId;
}
}
Contract Source Code
File 14 of 18: Math.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (utils/math/Math.sol)pragmasolidity ^0.8.0;/**
* @dev Standard math utilities missing in the Solidity language.
*/libraryMath{
enumRounding {
Down, // Toward negative infinity
Up, // Toward infinity
Zero // Toward zero
}
/**
* @dev Returns the largest of two numbers.
*/functionmax(uint256 a, uint256 b) internalpurereturns (uint256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two numbers.
*/functionmin(uint256 a, uint256 b) internalpurereturns (uint256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two numbers. The result is rounded towards
* zero.
*/functionaverage(uint256 a, uint256 b) internalpurereturns (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.
*/functionceilDiv(uint256 a, uint256 b) internalpurereturns (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.
*/functionmulDiv(uint256 x, uint256 y, uint256 denominator) internalpurereturns (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 productuint256 prod1; // Most significant 256 bits of the productassembly {
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.
*/functionmulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internalpurereturns (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).
*/functionsqrt(uint256 a) internalpurereturns (uint256) {
if (a ==0) {
return0;
}
// 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.
*/functionsqrt(uint256 a, Rounding rounding) internalpurereturns (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.
*/functionlog2(uint256 value) internalpurereturns (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.
*/functionlog2(uint256 value, Rounding rounding) internalpurereturns (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.
*/functionlog10(uint256 value) internalpurereturns (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.
*/functionlog10(uint256 value, Rounding rounding) internalpurereturns (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.
*/functionlog256(uint256 value) internalpurereturns (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.
*/functionlog256(uint256 value, Rounding rounding) internalpurereturns (uint256) {
unchecked {
uint256 result = log256(value);
return result + (rounding == Rounding.Up &&1<< (result <<3) < value ? 1 : 0);
}
}
}
Contract Source Code
File 15 of 18: Ownable.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)pragmasolidity ^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.
*/abstractcontractOwnableisContext{
addressprivate _owner;
eventOwnershipTransferred(addressindexed previousOwner, addressindexed 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.
*/modifieronlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/functionowner() publicviewvirtualreturns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/function_checkOwner() internalviewvirtual{
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.
*/functionrenounceOwnership() publicvirtualonlyOwner{
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/functiontransferOwnership(address newOwner) publicvirtualonlyOwner{
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) internalvirtual{
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.8.0) (utils/math/SignedMath.sol)pragmasolidity ^0.8.0;/**
* @dev Standard signed math utilities missing in the Solidity language.
*/librarySignedMath{
/**
* @dev Returns the largest of two signed numbers.
*/functionmax(int256 a, int256 b) internalpurereturns (int256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two signed numbers.
*/functionmin(int256 a, int256 b) internalpurereturns (int256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two signed numbers without overflow.
* The result is rounded towards zero.
*/functionaverage(int256 a, int256 b) internalpurereturns (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.
*/functionabs(int256 n) internalpurereturns (uint256) {
unchecked {
// must be unchecked in order to support `n = type(int256).min`returnuint256(n >=0 ? n : -n);
}
}
}
Contract Source Code
File 18 of 18: Strings.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (utils/Strings.sol)pragmasolidity ^0.8.0;import"./math/Math.sol";
import"./math/SignedMath.sol";
/**
* @dev String operations.
*/libraryStrings{
bytes16privateconstant _SYMBOLS ="0123456789abcdef";
uint8privateconstant _ADDRESS_LENGTH =20;
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/functiontoString(uint256 value) internalpurereturns (stringmemory) {
unchecked {
uint256 length = Math.log10(value) +1;
stringmemory buffer =newstring(length);
uint256 ptr;
/// @solidity memory-safe-assemblyassembly {
ptr :=add(buffer, add(32, length))
}
while (true) {
ptr--;
/// @solidity memory-safe-assemblyassembly {
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.
*/functiontoString(int256 value) internalpurereturns (stringmemory) {
returnstring(abi.encodePacked(value <0 ? "-" : "", toString(SignedMath.abs(value))));
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/functiontoHexString(uint256 value) internalpurereturns (stringmemory) {
unchecked {
return toHexString(value, Math.log256(value) +1);
}
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
*/functiontoHexString(uint256 value, uint256 length) internalpurereturns (stringmemory) {
bytesmemory buffer =newbytes(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");
returnstring(buffer);
}
/**
* @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
*/functiontoHexString(address addr) internalpurereturns (stringmemory) {
return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
}
/**
* @dev Returns true if the two strings are equal.
*/functionequal(stringmemory a, stringmemory b) internalpurereturns (bool) {
returnkeccak256(bytes(a)) ==keccak256(bytes(b));
}
}