// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (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;
}
}
Contract Source Code
File 2 of 8: 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 3 of 8: IERC721.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC721/IERC721.sol)pragmasolidity ^0.8.0;import"../../utils/introspection/IERC165.sol";
/**
* @dev Required interface of an ERC721 compliant contract.
*/interfaceIERC721isIERC165{
/**
* @dev Emitted when `tokenId` token is transferred from `from` to `to`.
*/eventTransfer(addressindexedfrom, addressindexed to, uint256indexed tokenId);
/**
* @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
*/eventApproval(addressindexed owner, addressindexed approved, uint256indexed tokenId);
/**
* @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
*/eventApprovalForAll(addressindexed owner, addressindexed operator, bool approved);
/**
* @dev Returns the number of tokens in ``owner``'s account.
*/functionbalanceOf(address owner) externalviewreturns (uint256 balance);
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/functionownerOf(uint256 tokenId) externalviewreturns (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.
*/functionsafeTransferFrom(addressfrom,
address to,
uint256 tokenId,
bytescalldata 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.
*/functionsafeTransferFrom(addressfrom,
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.
*/functiontransferFrom(addressfrom,
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.
*/functionapprove(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.
*/functionsetApprovalForAll(address operator, bool _approved) external;
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/functiongetApproved(uint256 tokenId) externalviewreturns (address operator);
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}
*/functionisApprovedForAll(address owner, address operator) externalviewreturns (bool);
}
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.8.0) (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) {
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.
*/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 10, 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 *8) < value ? 1 : 0);
}
}
}
Contract Source Code
File 6 of 8: Ownable.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.7.0) (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 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.
*/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);
}
}