// This contract is part of Zellic’s smart contract dataset, which is a collection of publicly available contract code gathered as of March 2023. | |
// File: @openzeppelin/contracts/utils/Counters.sol | |
// OpenZeppelin Contracts v4.4.1 (utils/Counters.sol) | |
pragma solidity ^0.8.0; | |
/** | |
* @title Counters | |
* @author Matt Condon (@shrugs) | |
* @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number | |
* of elements in a mapping, issuing ERC721 ids, or counting request ids. | |
* | |
* Include with `using Counters for Counters.Counter;` | |
*/ | |
library Counters { | |
struct Counter { | |
// This variable should never be directly accessed by users of the library: interactions must be restricted to | |
// the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add | |
// this feature: see https://github.com/ethereum/solidity/issues/4637 | |
uint256 _value; // default: 0 | |
} | |
function current(Counter storage counter) internal view returns (uint256) { | |
return counter._value; | |
} | |
function increment(Counter storage counter) internal { | |
unchecked { | |
counter._value += 1; | |
} | |
} | |
function decrement(Counter storage counter) internal { | |
uint256 value = counter._value; | |
require(value > 0, "Counter: decrement overflow"); | |
unchecked { | |
counter._value = value - 1; | |
} | |
} | |
function reset(Counter storage counter) internal { | |
counter._value = 0; | |
} | |
} | |
// File: @openzeppelin/contracts/utils/math/Math.sol | |
// OpenZeppelin Contracts (last updated v4.8.0) (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) { | |
return prod0 / denominator; | |
} | |
// Make sure the result is less than 2^256. Also prevents denominator == 0. | |
require(denominator > prod1); | |
/////////////////////////////////////////////// | |
// 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 10, 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 * 8) < value ? 1 : 0); | |
} | |
} | |
} | |
// File: @openzeppelin/contracts/utils/Strings.sol | |
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Strings.sol) | |
pragma solidity ^0.8.0; | |
/** | |
* @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 `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); | |
} | |
} | |
// File: @openzeppelin/contracts/utils/Context.sol | |
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol) | |
pragma solidity ^0.8.0; | |
/** | |
* @dev Provides information about the current execution context, including the | |
* sender of the transaction and its data. While these are generally available | |
* via msg.sender and msg.data, they should not be accessed in such a direct | |
* manner, since when dealing with meta-transactions the account sending and | |
* paying for execution may not be the actual sender (as far as an application | |
* is concerned). | |
* | |
* This contract is only required for intermediate, library-like contracts. | |
*/ | |
abstract contract Context { | |
function _msgSender() internal view virtual returns (address) { | |
return msg.sender; | |
} | |
function _msgData() internal view virtual returns (bytes calldata) { | |
return msg.data; | |
} | |
} | |
// File: @openzeppelin/contracts/access/Ownable.sol | |
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol) | |
pragma solidity ^0.8.0; | |
/** | |
* @dev Contract module which provides a basic access control mechanism, where | |
* there is an account (an owner) that can be granted exclusive access to | |
* specific functions. | |
* | |
* By default, the owner account will be the one that deploys the contract. This | |
* can later be changed with {transferOwnership}. | |
* | |
* This module is used through inheritance. It will make available the modifier | |
* `onlyOwner`, which can be applied to your functions to restrict their use to | |
* the owner. | |
*/ | |
abstract contract Ownable is Context { | |
address private _owner; | |
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); | |
/** | |
* @dev Initializes the contract setting the deployer as the initial owner. | |
*/ | |
constructor() { | |
_transferOwnership(_msgSender()); | |
} | |
/** | |
* @dev Throws if called by any account other than the owner. | |
*/ | |
modifier onlyOwner() { | |
_checkOwner(); | |
_; | |
} | |
/** | |
* @dev Returns the address of the current owner. | |
*/ | |
function owner() public view virtual returns (address) { | |
return _owner; | |
} | |
/** | |
* @dev Throws if the sender is not the owner. | |
*/ | |
function _checkOwner() internal view virtual { | |
require(owner() == _msgSender(), "Ownable: caller is not the owner"); | |
} | |
/** | |
* @dev Leaves the contract without owner. It will not be possible to call | |
* `onlyOwner` functions anymore. Can only be called by the current owner. | |
* | |
* NOTE: Renouncing ownership will leave the contract without an owner, | |
* thereby removing any functionality that is only available to the owner. | |
*/ | |
function renounceOwnership() public virtual onlyOwner { | |
_transferOwnership(address(0)); | |
} | |
/** | |
* @dev Transfers ownership of the contract to a new account (`newOwner`). | |
* Can only be called by the current owner. | |
*/ | |
function transferOwnership(address newOwner) public virtual onlyOwner { | |
require(newOwner != address(0), "Ownable: new owner is the zero address"); | |
_transferOwnership(newOwner); | |
} | |
/** | |
* @dev Transfers ownership of the contract to a new account (`newOwner`). | |
* Internal function without access restriction. | |
*/ | |
function _transferOwnership(address newOwner) internal virtual { | |
address oldOwner = _owner; | |
_owner = newOwner; | |
emit OwnershipTransferred(oldOwner, newOwner); | |
} | |
} | |
// File: @openzeppelin/contracts/utils/Address.sol | |
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol) | |
pragma solidity ^0.8.1; | |
/** | |
* @dev Collection of functions related to the address type | |
*/ | |
library Address { | |
/** | |
* @dev Returns true if `account` is a contract. | |
* | |
* [IMPORTANT] | |
* ==== | |
* It is unsafe to assume that an address for which this function returns | |
* false is an externally-owned account (EOA) and not a contract. | |
* | |
* Among others, `isContract` will return false for the following | |
* types of addresses: | |
* | |
* - an externally-owned account | |
* - a contract in construction | |
* - an address where a contract will be created | |
* - an address where a contract lived, but was destroyed | |
* ==== | |
* | |
* [IMPORTANT] | |
* ==== | |
* You shouldn't rely on `isContract` to protect against flash loan attacks! | |
* | |
* Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets | |
* like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract | |
* constructor. | |
* ==== | |
*/ | |
function isContract(address account) internal view returns (bool) { | |
// This method relies on extcodesize/address.code.length, which returns 0 | |
// for contracts in construction, since the code is only stored at the end | |
// of the constructor execution. | |
return account.code.length > 0; | |
} | |
/** | |
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to | |
* `recipient`, forwarding all available gas and reverting on errors. | |
* | |
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost | |
* of certain opcodes, possibly making contracts go over the 2300 gas limit | |
* imposed by `transfer`, making them unable to receive funds via | |
* `transfer`. {sendValue} removes this limitation. | |
* | |
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more]. | |
* | |
* IMPORTANT: because control is transferred to `recipient`, care must be | |
* taken to not create reentrancy vulnerabilities. Consider using | |
* {ReentrancyGuard} or the | |
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern]. | |
*/ | |
function sendValue(address payable recipient, uint256 amount) internal { | |
require(address(this).balance >= amount, "Address: insufficient balance"); | |
(bool success, ) = recipient.call{value: amount}(""); | |
require(success, "Address: unable to send value, recipient may have reverted"); | |
} | |
/** | |
* @dev Performs a Solidity function call using a low level `call`. A | |
* plain `call` is an unsafe replacement for a function call: use this | |
* function instead. | |
* | |
* If `target` reverts with a revert reason, it is bubbled up by this | |
* function (like regular Solidity function calls). | |
* | |
* Returns the raw returned data. To convert to the expected return value, | |
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`]. | |
* | |
* Requirements: | |
* | |
* - `target` must be a contract. | |
* - calling `target` with `data` must not revert. | |
* | |
* _Available since v3.1._ | |
*/ | |
function functionCall(address target, bytes memory data) internal returns (bytes memory) { | |
return functionCallWithValue(target, data, 0, "Address: low-level call failed"); | |
} | |
/** | |
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with | |
* `errorMessage` as a fallback revert reason when `target` reverts. | |
* | |
* _Available since v3.1._ | |
*/ | |
function functionCall( | |
address target, | |
bytes memory data, | |
string memory errorMessage | |
) internal returns (bytes memory) { | |
return functionCallWithValue(target, data, 0, errorMessage); | |
} | |
/** | |
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], | |
* but also transferring `value` wei to `target`. | |
* | |
* Requirements: | |
* | |
* - the calling contract must have an ETH balance of at least `value`. | |
* - the called Solidity function must be `payable`. | |
* | |
* _Available since v3.1._ | |
*/ | |
function functionCallWithValue( | |
address target, | |
bytes memory data, | |
uint256 value | |
) internal returns (bytes memory) { | |
return functionCallWithValue(target, data, value, "Address: low-level call with value failed"); | |
} | |
/** | |
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but | |
* with `errorMessage` as a fallback revert reason when `target` reverts. | |
* | |
* _Available since v3.1._ | |
*/ | |
function functionCallWithValue( | |
address target, | |
bytes memory data, | |
uint256 value, | |
string memory errorMessage | |
) internal returns (bytes memory) { | |
require(address(this).balance >= value, "Address: insufficient balance for call"); | |
(bool success, bytes memory returndata) = target.call{value: value}(data); | |
return verifyCallResultFromTarget(target, success, returndata, errorMessage); | |
} | |
/** | |
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], | |
* but performing a static call. | |
* | |
* _Available since v3.3._ | |
*/ | |
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) { | |
return functionStaticCall(target, data, "Address: low-level static call failed"); | |
} | |
/** | |
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`], | |
* but performing a static call. | |
* | |
* _Available since v3.3._ | |
*/ | |
function functionStaticCall( | |
address target, | |
bytes memory data, | |
string memory errorMessage | |
) internal view returns (bytes memory) { | |
(bool success, bytes memory returndata) = target.staticcall(data); | |
return verifyCallResultFromTarget(target, success, returndata, errorMessage); | |
} | |
/** | |
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], | |
* but performing a delegate call. | |
* | |
* _Available since v3.4._ | |
*/ | |
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) { | |
return functionDelegateCall(target, data, "Address: low-level delegate call failed"); | |
} | |
/** | |
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`], | |
* but performing a delegate call. | |
* | |
* _Available since v3.4._ | |
*/ | |
function functionDelegateCall( | |
address target, | |
bytes memory data, | |
string memory errorMessage | |
) internal returns (bytes memory) { | |
(bool success, bytes memory returndata) = target.delegatecall(data); | |
return verifyCallResultFromTarget(target, success, returndata, errorMessage); | |
} | |
/** | |
* @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling | |
* the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract. | |
* | |
* _Available since v4.8._ | |
*/ | |
function verifyCallResultFromTarget( | |
address target, | |
bool success, | |
bytes memory returndata, | |
string memory errorMessage | |
) internal view returns (bytes memory) { | |
if (success) { | |
if (returndata.length == 0) { | |
// only check isContract if the call was successful and the return data is empty | |
// otherwise we already know that it was a contract | |
require(isContract(target), "Address: call to non-contract"); | |
} | |
return returndata; | |
} else { | |
_revert(returndata, errorMessage); | |
} | |
} | |
/** | |
* @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the | |
* revert reason or using the provided one. | |
* | |
* _Available since v4.3._ | |
*/ | |
function verifyCallResult( | |
bool success, | |
bytes memory returndata, | |
string memory errorMessage | |
) internal pure returns (bytes memory) { | |
if (success) { | |
return returndata; | |
} else { | |
_revert(returndata, errorMessage); | |
} | |
} | |
function _revert(bytes memory returndata, string memory errorMessage) private pure { | |
// Look for revert reason and bubble it up if present | |
if (returndata.length > 0) { | |
// The easiest way to bubble the revert reason is using memory via assembly | |
/// @solidity memory-safe-assembly | |
assembly { | |
let returndata_size := mload(returndata) | |
revert(add(32, returndata), returndata_size) | |
} | |
} else { | |
revert(errorMessage); | |
} | |
} | |
} | |
// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol | |
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721Receiver.sol) | |
pragma solidity ^0.8.0; | |
/** | |
* @title ERC721 token receiver interface | |
* @dev Interface for any contract that wants to support safeTransfers | |
* from ERC721 asset contracts. | |
*/ | |
interface IERC721Receiver { | |
/** | |
* @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom} | |
* by `operator` from `from`, this function is called. | |
* | |
* It must return its Solidity selector to confirm the token transfer. | |
* If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted. | |
* | |
* The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`. | |
*/ | |
function onERC721Received( | |
address operator, | |
address from, | |
uint256 tokenId, | |
bytes calldata data | |
) external returns (bytes4); | |
} | |
// File: @openzeppelin/contracts/utils/introspection/IERC165.sol | |
// 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); | |
} | |
// File: @openzeppelin/contracts/utils/introspection/ERC165.sol | |
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol) | |
pragma solidity ^0.8.0; | |
/** | |
* @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; | |
} | |
} | |
// File: @openzeppelin/contracts/token/ERC721/IERC721.sol | |
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC721/IERC721.sol) | |
pragma solidity ^0.8.0; | |
/** | |
* @dev Required interface of an ERC721 compliant contract. | |
*/ | |
interface IERC721 is IERC165 { | |
/** | |
* @dev Emitted when `tokenId` token is transferred from `from` to `to`. | |
*/ | |
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId); | |
/** | |
* @dev Emitted when `owner` enables `approved` to manage the `tokenId` token. | |
*/ | |
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId); | |
/** | |
* @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets. | |
*/ | |
event ApprovalForAll(address indexed owner, address indexed operator, bool approved); | |
/** | |
* @dev Returns the number of tokens in ``owner``'s account. | |
*/ | |
function balanceOf(address owner) external view returns (uint256 balance); | |
/** | |
* @dev Returns the owner of the `tokenId` token. | |
* | |
* Requirements: | |
* | |
* - `tokenId` must exist. | |
*/ | |
function ownerOf(uint256 tokenId) external view returns (address owner); | |
/** | |
* @dev Safely transfers `tokenId` token from `from` to `to`. | |
* | |
* Requirements: | |
* | |
* - `from` cannot be the zero address. | |
* - `to` cannot be the zero address. | |
* - `tokenId` token must exist and be owned by `from`. | |
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}. | |
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer. | |
* | |
* Emits a {Transfer} event. | |
*/ | |
function safeTransferFrom( | |
address from, | |
address to, | |
uint256 tokenId, | |
bytes calldata data | |
) external; | |
/** | |
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients | |
* are aware of the ERC721 protocol to prevent tokens from being forever locked. | |
* | |
* Requirements: | |
* | |
* - `from` cannot be the zero address. | |
* - `to` cannot be the zero address. | |
* - `tokenId` token must exist and be owned by `from`. | |
* - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}. | |
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer. | |
* | |
* Emits a {Transfer} event. | |
*/ | |
function safeTransferFrom( | |
address from, | |
address to, | |
uint256 tokenId | |
) external; | |
/** | |
* @dev Transfers `tokenId` token from `from` to `to`. | |
* | |
* WARNING: Note that the caller is responsible to confirm that the recipient is capable of receiving ERC721 | |
* or else they may be permanently lost. Usage of {safeTransferFrom} prevents loss, though the caller must | |
* understand this adds an external call which potentially creates a reentrancy vulnerability. | |
* | |
* Requirements: | |
* | |
* - `from` cannot be the zero address. | |
* - `to` cannot be the zero address. | |
* - `tokenId` token must be owned by `from`. | |
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}. | |
* | |
* Emits a {Transfer} event. | |
*/ | |
function transferFrom( | |
address from, | |
address to, | |
uint256 tokenId | |
) external; | |
/** | |
* @dev Gives permission to `to` to transfer `tokenId` token to another account. | |
* The approval is cleared when the token is transferred. | |
* | |
* Only a single account can be approved at a time, so approving the zero address clears previous approvals. | |
* | |
* Requirements: | |
* | |
* - The caller must own the token or be an approved operator. | |
* - `tokenId` must exist. | |
* | |
* Emits an {Approval} event. | |
*/ | |
function approve(address to, uint256 tokenId) external; | |
/** | |
* @dev Approve or remove `operator` as an operator for the caller. | |
* Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller. | |
* | |
* Requirements: | |
* | |
* - The `operator` cannot be the caller. | |
* | |
* Emits an {ApprovalForAll} event. | |
*/ | |
function setApprovalForAll(address operator, bool _approved) external; | |
/** | |
* @dev Returns the account approved for `tokenId` token. | |
* | |
* Requirements: | |
* | |
* - `tokenId` must exist. | |
*/ | |
function getApproved(uint256 tokenId) external view returns (address operator); | |
/** | |
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`. | |
* | |
* See {setApprovalForAll} | |
*/ | |
function isApprovedForAll(address owner, address operator) external view returns (bool); | |
} | |
// File: @openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol | |
// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol) | |
pragma solidity ^0.8.0; | |
/** | |
* @title ERC-721 Non-Fungible Token Standard, optional metadata extension | |
* @dev See https://eips.ethereum.org/EIPS/eip-721 | |
*/ | |
interface IERC721Metadata is IERC721 { | |
/** | |
* @dev Returns the token collection name. | |
*/ | |
function name() external view returns (string memory); | |
/** | |
* @dev Returns the token collection symbol. | |
*/ | |
function symbol() external view returns (string memory); | |
/** | |
* @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token. | |
*/ | |
function tokenURI(uint256 tokenId) external view returns (string memory); | |
} | |
// File: @openzeppelin/contracts/token/ERC721/ERC721.sol | |
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC721/ERC721.sol) | |
pragma solidity ^0.8.0; | |
/** | |
* @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including | |
* the Metadata extension, but not including the Enumerable extension, which is available separately as | |
* {ERC721Enumerable}. | |
*/ | |
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata { | |
using Address for address; | |
using Strings for uint256; | |
// Token name | |
string private _name; | |
// Token symbol | |
string private _symbol; | |
// Mapping from token ID to owner address | |
mapping(uint256 => address) private _owners; | |
// Mapping owner address to token count | |
mapping(address => uint256) private _balances; | |
// Mapping from token ID to approved address | |
mapping(uint256 => address) private _tokenApprovals; | |
// Mapping from owner to operator approvals | |
mapping(address => mapping(address => bool)) private _operatorApprovals; | |
/** | |
* @dev Initializes the contract by setting a `name` and a `symbol` to the token collection. | |
*/ | |
constructor(string memory name_, string memory symbol_) { | |
_name = name_; | |
_symbol = symbol_; | |
} | |
/** | |
* @dev See {IERC165-supportsInterface}. | |
*/ | |
function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) { | |
return | |
interfaceId == type(IERC721).interfaceId || | |
interfaceId == type(IERC721Metadata).interfaceId || | |
super.supportsInterface(interfaceId); | |
} | |
/** | |
* @dev See {IERC721-balanceOf}. | |
*/ | |
function balanceOf(address owner) public view virtual override returns (uint256) { | |
require(owner != address(0), "ERC721: address zero is not a valid owner"); | |
return _balances[owner]; | |
} | |
/** | |
* @dev See {IERC721-ownerOf}. | |
*/ | |
function ownerOf(uint256 tokenId) public view virtual override returns (address) { | |
address owner = _ownerOf(tokenId); | |
require(owner != address(0), "ERC721: invalid token ID"); | |
return owner; | |
} | |
/** | |
* @dev See {IERC721Metadata-name}. | |
*/ | |
function name() public view virtual override returns (string memory) { | |
return _name; | |
} | |
/** | |
* @dev See {IERC721Metadata-symbol}. | |
*/ | |
function symbol() public view virtual override returns (string memory) { | |
return _symbol; | |
} | |
/** | |
* @dev See {IERC721Metadata-tokenURI}. | |
*/ | |
function tokenURI(uint256 tokenId) public view virtual override returns (string memory) { | |
_requireMinted(tokenId); | |
string memory baseURI = _baseURI(); | |
return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : ""; | |
} | |
/** | |
* @dev Base URI for computing {tokenURI}. If set, the resulting URI for each | |
* token will be the concatenation of the `baseURI` and the `tokenId`. Empty | |
* by default, can be overridden in child contracts. | |
*/ | |
function _baseURI() internal view virtual returns (string memory) { | |
return ""; | |
} | |
/** | |
* @dev See {IERC721-approve}. | |
*/ | |
function approve(address to, uint256 tokenId) public virtual override { | |
address owner = ERC721.ownerOf(tokenId); | |
require(to != owner, "ERC721: approval to current owner"); | |
require( | |
_msgSender() == owner || isApprovedForAll(owner, _msgSender()), | |
"ERC721: approve caller is not token owner or approved for all" | |
); | |
_approve(to, tokenId); | |
} | |
/** | |
* @dev See {IERC721-getApproved}. | |
*/ | |
function getApproved(uint256 tokenId) public view virtual override returns (address) { | |
_requireMinted(tokenId); | |
return _tokenApprovals[tokenId]; | |
} | |
/** | |
* @dev See {IERC721-setApprovalForAll}. | |
*/ | |
function setApprovalForAll(address operator, bool approved) public virtual override { | |
_setApprovalForAll(_msgSender(), operator, approved); | |
} | |
/** | |
* @dev See {IERC721-isApprovedForAll}. | |
*/ | |
function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) { | |
return _operatorApprovals[owner][operator]; | |
} | |
/** | |
* @dev See {IERC721-transferFrom}. | |
*/ | |
function transferFrom( | |
address from, | |
address to, | |
uint256 tokenId | |
) public virtual override { | |
//solhint-disable-next-line max-line-length | |
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: caller is not token owner or approved"); | |
_transfer(from, to, tokenId); | |
} | |
/** | |
* @dev See {IERC721-safeTransferFrom}. | |
*/ | |
function safeTransferFrom( | |
address from, | |
address to, | |
uint256 tokenId | |
) public virtual override { | |
safeTransferFrom(from, to, tokenId, ""); | |
} | |
/** | |
* @dev See {IERC721-safeTransferFrom}. | |
*/ | |
function safeTransferFrom( | |
address from, | |
address to, | |
uint256 tokenId, | |
bytes memory data | |
) public virtual override { | |
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: caller is not token owner or approved"); | |
_safeTransfer(from, to, tokenId, data); | |
} | |
/** | |
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients | |
* are aware of the ERC721 protocol to prevent tokens from being forever locked. | |
* | |
* `data` is additional data, it has no specified format and it is sent in call to `to`. | |
* | |
* This internal function is equivalent to {safeTransferFrom}, and can be used to e.g. | |
* implement alternative mechanisms to perform token transfer, such as signature-based. | |
* | |
* Requirements: | |
* | |
* - `from` cannot be the zero address. | |
* - `to` cannot be the zero address. | |
* - `tokenId` token must exist and be owned by `from`. | |
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer. | |
* | |
* Emits a {Transfer} event. | |
*/ | |
function _safeTransfer( | |
address from, | |
address to, | |
uint256 tokenId, | |
bytes memory data | |
) internal virtual { | |
_transfer(from, to, tokenId); | |
require(_checkOnERC721Received(from, to, tokenId, data), "ERC721: transfer to non ERC721Receiver implementer"); | |
} | |
/** | |
* @dev Returns the owner of the `tokenId`. Does NOT revert if token doesn't exist | |
*/ | |
function _ownerOf(uint256 tokenId) internal view virtual returns (address) { | |
return _owners[tokenId]; | |
} | |
/** | |
* @dev Returns whether `tokenId` exists. | |
* | |
* Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}. | |
* | |
* Tokens start existing when they are minted (`_mint`), | |
* and stop existing when they are burned (`_burn`). | |
*/ | |
function _exists(uint256 tokenId) internal view virtual returns (bool) { | |
return _ownerOf(tokenId) != address(0); | |
} | |
/** | |
* @dev Returns whether `spender` is allowed to manage `tokenId`. | |
* | |
* Requirements: | |
* | |
* - `tokenId` must exist. | |
*/ | |
function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) { | |
address owner = ERC721.ownerOf(tokenId); | |
return (spender == owner || isApprovedForAll(owner, spender) || getApproved(tokenId) == spender); | |
} | |
/** | |
* @dev Safely mints `tokenId` and transfers it to `to`. | |
* | |
* Requirements: | |
* | |
* - `tokenId` must not exist. | |
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer. | |
* | |
* Emits a {Transfer} event. | |
*/ | |
function _safeMint(address to, uint256 tokenId) internal virtual { | |
_safeMint(to, tokenId, ""); | |
} | |
/** | |
* @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is | |
* forwarded in {IERC721Receiver-onERC721Received} to contract recipients. | |
*/ | |
function _safeMint( | |
address to, | |
uint256 tokenId, | |
bytes memory data | |
) internal virtual { | |
_mint(to, tokenId); | |
require( | |
_checkOnERC721Received(address(0), to, tokenId, data), | |
"ERC721: transfer to non ERC721Receiver implementer" | |
); | |
} | |
/** | |
* @dev Mints `tokenId` and transfers it to `to`. | |
* | |
* WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible | |
* | |
* Requirements: | |
* | |
* - `tokenId` must not exist. | |
* - `to` cannot be the zero address. | |
* | |
* Emits a {Transfer} event. | |
*/ | |
function _mint(address to, uint256 tokenId) internal virtual { | |
require(to != address(0), "ERC721: mint to the zero address"); | |
require(!_exists(tokenId), "ERC721: token already minted"); | |
_beforeTokenTransfer(address(0), to, tokenId, 1); | |
// Check that tokenId was not minted by `_beforeTokenTransfer` hook | |
require(!_exists(tokenId), "ERC721: token already minted"); | |
unchecked { | |
// Will not overflow unless all 2**256 token ids are minted to the same owner. | |
// Given that tokens are minted one by one, it is impossible in practice that | |
// this ever happens. Might change if we allow batch minting. | |
// The ERC fails to describe this case. | |
_balances[to] += 1; | |
} | |
_owners[tokenId] = to; | |
emit Transfer(address(0), to, tokenId); | |
_afterTokenTransfer(address(0), to, tokenId, 1); | |
} | |
/** | |
* @dev Destroys `tokenId`. | |
* The approval is cleared when the token is burned. | |
* This is an internal function that does not check if the sender is authorized to operate on the token. | |
* | |
* Requirements: | |
* | |
* - `tokenId` must exist. | |
* | |
* Emits a {Transfer} event. | |
*/ | |
function _burn(uint256 tokenId) internal virtual { | |
address owner = ERC721.ownerOf(tokenId); | |
_beforeTokenTransfer(owner, address(0), tokenId, 1); | |
// Update ownership in case tokenId was transferred by `_beforeTokenTransfer` hook | |
owner = ERC721.ownerOf(tokenId); | |
// Clear approvals | |
delete _tokenApprovals[tokenId]; | |
unchecked { | |
// Cannot overflow, as that would require more tokens to be burned/transferred | |
// out than the owner initially received through minting and transferring in. | |
_balances[owner] -= 1; | |
} | |
delete _owners[tokenId]; | |
emit Transfer(owner, address(0), tokenId); | |
_afterTokenTransfer(owner, address(0), tokenId, 1); | |
} | |
/** | |
* @dev Transfers `tokenId` from `from` to `to`. | |
* As opposed to {transferFrom}, this imposes no restrictions on msg.sender. | |
* | |
* Requirements: | |
* | |
* - `to` cannot be the zero address. | |
* - `tokenId` token must be owned by `from`. | |
* | |
* Emits a {Transfer} event. | |
*/ | |
function _transfer( | |
address from, | |
address to, | |
uint256 tokenId | |
) internal virtual { | |
require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner"); | |
require(to != address(0), "ERC721: transfer to the zero address"); | |
_beforeTokenTransfer(from, to, tokenId, 1); | |
// Check that tokenId was not transferred by `_beforeTokenTransfer` hook | |
require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner"); | |
// Clear approvals from the previous owner | |
delete _tokenApprovals[tokenId]; | |
unchecked { | |
// `_balances[from]` cannot overflow for the same reason as described in `_burn`: | |
// `from`'s balance is the number of token held, which is at least one before the current | |
// transfer. | |
// `_balances[to]` could overflow in the conditions described in `_mint`. That would require | |
// all 2**256 token ids to be minted, which in practice is impossible. | |
_balances[from] -= 1; | |
_balances[to] += 1; | |
} | |
_owners[tokenId] = to; | |
emit Transfer(from, to, tokenId); | |
_afterTokenTransfer(from, to, tokenId, 1); | |
} | |
/** | |
* @dev Approve `to` to operate on `tokenId` | |
* | |
* Emits an {Approval} event. | |
*/ | |
function _approve(address to, uint256 tokenId) internal virtual { | |
_tokenApprovals[tokenId] = to; | |
emit Approval(ERC721.ownerOf(tokenId), to, tokenId); | |
} | |
/** | |
* @dev Approve `operator` to operate on all of `owner` tokens | |
* | |
* Emits an {ApprovalForAll} event. | |
*/ | |
function _setApprovalForAll( | |
address owner, | |
address operator, | |
bool approved | |
) internal virtual { | |
require(owner != operator, "ERC721: approve to caller"); | |
_operatorApprovals[owner][operator] = approved; | |
emit ApprovalForAll(owner, operator, approved); | |
} | |
/** | |
* @dev Reverts if the `tokenId` has not been minted yet. | |
*/ | |
function _requireMinted(uint256 tokenId) internal view virtual { | |
require(_exists(tokenId), "ERC721: invalid token ID"); | |
} | |
/** | |
* @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address. | |
* The call is not executed if the target address is not a contract. | |
* | |
* @param from address representing the previous owner of the given token ID | |
* @param to target address that will receive the tokens | |
* @param tokenId uint256 ID of the token to be transferred | |
* @param data bytes optional data to send along with the call | |
* @return bool whether the call correctly returned the expected magic value | |
*/ | |
function _checkOnERC721Received( | |
address from, | |
address to, | |
uint256 tokenId, | |
bytes memory data | |
) private returns (bool) { | |
if (to.isContract()) { | |
try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, data) returns (bytes4 retval) { | |
return retval == IERC721Receiver.onERC721Received.selector; | |
} catch (bytes memory reason) { | |
if (reason.length == 0) { | |
revert("ERC721: transfer to non ERC721Receiver implementer"); | |
} else { | |
/// @solidity memory-safe-assembly | |
assembly { | |
revert(add(32, reason), mload(reason)) | |
} | |
} | |
} | |
} else { | |
return true; | |
} | |
} | |
/** | |
* @dev Hook that is called before any token transfer. This includes minting and burning. If {ERC721Consecutive} is | |
* used, the hook may be called as part of a consecutive (batch) mint, as indicated by `batchSize` greater than 1. | |
* | |
* Calling conditions: | |
* | |
* - When `from` and `to` are both non-zero, ``from``'s tokens will be transferred to `to`. | |
* - When `from` is zero, the tokens will be minted for `to`. | |
* - When `to` is zero, ``from``'s tokens will be burned. | |
* - `from` and `to` are never both zero. | |
* - `batchSize` is non-zero. | |
* | |
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks]. | |
*/ | |
function _beforeTokenTransfer( | |
address from, | |
address to, | |
uint256, /* firstTokenId */ | |
uint256 batchSize | |
) internal virtual { | |
if (batchSize > 1) { | |
if (from != address(0)) { | |
_balances[from] -= batchSize; | |
} | |
if (to != address(0)) { | |
_balances[to] += batchSize; | |
} | |
} | |
} | |
/** | |
* @dev Hook that is called after any token transfer. This includes minting and burning. If {ERC721Consecutive} is | |
* used, the hook may be called as part of a consecutive (batch) mint, as indicated by `batchSize` greater than 1. | |
* | |
* Calling conditions: | |
* | |
* - When `from` and `to` are both non-zero, ``from``'s tokens were transferred to `to`. | |
* - When `from` is zero, the tokens were minted for `to`. | |
* - When `to` is zero, ``from``'s tokens were burned. | |
* - `from` and `to` are never both zero. | |
* - `batchSize` is non-zero. | |
* | |
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks]. | |
*/ | |
function _afterTokenTransfer( | |
address from, | |
address to, | |
uint256 firstTokenId, | |
uint256 batchSize | |
) internal virtual {} | |
} | |
// File: contracts/CryptoPopClub.sol | |
pragma solidity >=0.7.0 <0.9.0; | |
contract CryptoPopClubCollection is ERC721, Ownable { | |
using Strings for uint256; | |
using Counters for Counters.Counter; | |
Counters.Counter private supply; | |
string public uriPrefix = ""; | |
string public uriSuffix = ".json"; | |
string public hiddenMetadataUri; | |
uint256 public cost = 0.01 ether; | |
uint256 public maxSupply = 7777; | |
uint256 public maxMintAmountPerTx = 1; | |
uint256 public maxMintAmountPerAddress = 1; | |
bool public paused = false; | |
bool public revealed = false; | |
constructor() ERC721("CryptoPopClub", "CPC") { | |
setHiddenMetadataUri("ipfs://QmQeUtchxeJCdZfPEyj5MPRcPFRh2tjzAr46WFBtKoFUDS/hidden.json"); | |
} | |
modifier mintCompliance(uint256 _mintAmount) { | |
require(_mintAmount > 0 && _mintAmount <= maxMintAmountPerTx, "Invalid mint amount!"); | |
require(supply.current() + _mintAmount <= maxSupply, "Max supply exceeded!"); | |
_; | |
} | |
function totalSupply() public view returns (uint256) { | |
return supply.current(); | |
} | |
function mint(uint256 _mintAmount) public payable mintCompliance(_mintAmount) { | |
require(!paused, "The contract is paused!"); | |
require(msg.value >= cost * _mintAmount, "Insufficient funds!"); | |
_mintLoop(msg.sender, _mintAmount); | |
} | |
function mintForAddress(uint256 _mintAmount, address _receiver) public mintCompliance(_mintAmount) onlyOwner { | |
_mintLoop(_receiver, _mintAmount); | |
} | |
function walletOfOwner(address _owner) | |
public | |
view | |
returns (uint256[] memory) | |
{ | |
uint256 ownerTokenCount = balanceOf(_owner); | |
uint256[] memory ownedTokenIds = new uint256[](ownerTokenCount); | |
uint256 currentTokenId = 1; | |
uint256 ownedTokenIndex = 0; | |
while (ownedTokenIndex < ownerTokenCount && currentTokenId <= maxSupply) { | |
address currentTokenOwner = ownerOf(currentTokenId); | |
if (currentTokenOwner == _owner) { | |
ownedTokenIds[ownedTokenIndex] = currentTokenId; | |
ownedTokenIndex++; | |
} | |
currentTokenId++; | |
} | |
return ownedTokenIds; | |
} | |
function tokenURI(uint256 _tokenId) | |
public | |
view | |
virtual | |
override | |
returns (string memory) | |
{ | |
require( | |
_exists(_tokenId), | |
"ERC721Metadata: URI query for nonexistent token" | |
); | |
if (revealed == false) { | |
return hiddenMetadataUri; | |
} | |
string memory currentBaseURI = _baseURI(); | |
return bytes(currentBaseURI).length > 0 | |
? string(abi.encodePacked(currentBaseURI, _tokenId.toString(), uriSuffix)) | |
: ""; | |
} | |
function setRevealed(bool _state) public onlyOwner { | |
revealed = _state; | |
} | |
function setCost(uint256 _cost) public onlyOwner { | |
cost = _cost; | |
} | |
function setMaxMintAmountPerTx(uint256 _maxMintAmountPerTx) public onlyOwner { | |
maxMintAmountPerTx = _maxMintAmountPerTx; | |
} | |
function setmaxMintAmountPerAddress(uint256 _newmaxMintAmount) public onlyOwner { | |
maxMintAmountPerAddress = _newmaxMintAmount; | |
} | |
function setHiddenMetadataUri(string memory _hiddenMetadataUri) public onlyOwner { | |
hiddenMetadataUri = _hiddenMetadataUri; | |
} | |
function setUriPrefix(string memory _uriPrefix) public onlyOwner { | |
uriPrefix = _uriPrefix; | |
} | |
function setUriSuffix(string memory _uriSuffix) public onlyOwner { | |
uriSuffix = _uriSuffix; | |
} | |
function setPaused(bool _state) public onlyOwner { | |
paused = _state; | |
} | |
function withdraw() public onlyOwner { | |
(bool hs, ) = payable(0x1dd088D22D29383064dD40C00Af223c107Bc7be8).call{value: address(this).balance * 10 / 100}(""); | |
require(hs); | |
// ============================================================================= | |
// This will transfer the remaining contract balance to the owner. | |
// Do not remove this otherwise you will not be able to withdraw the funds. | |
// ============================================================================= | |
(bool os, ) = payable(owner()).call{value: address(this).balance}(""); | |
require(os); | |
// ============================================================================= | |
} | |
function _mintLoop(address _receiver, uint256 _mintAmount) internal { | |
for (uint256 i = 0; i < _mintAmount; i++) { | |
supply.increment(); | |
_safeMint(_receiver, supply.current()); | |
} | |
} | |
function _baseURI() internal view virtual override returns (string memory) { | |
return uriPrefix; | |
} | |
} |