Contract Source Code:
// SPDX-License-Identifier: AGPL-3.0
pragma solidity 0.8.9;
import "Pausable.sol";
import "ERC721ABurnable.sol";
abstract contract ContractGlossary {
function getAddress(string memory name)
public
view
virtual
returns (address);
}
abstract contract Farmer {
function minFarmSizeByType(string memory name)
public
view
virtual
returns (uint256);
function minStableTerm() public view virtual returns (uint256);
function maxStableTerm() public view virtual returns (uint256);
function maxFarmSize() public view virtual returns (uint256);
function minDestablingFee() public view virtual returns (uint256);
function maxOwnerFee() public view virtual returns (uint256);
}
abstract contract Stabler {
function ownerOf(uint256 tokenId) public view virtual returns (address);
}
contract Land is ERC721ABurnable, Pausable {
uint256 public _tokenIdCounter;
address public skyFallsPyramidAddress;
address private extMintAddress;
address public FarmAddress;
Farmer FarmContract;
string public _baseTokenURI;
uint256 private _maxSupply;
mapping(uint256 => string) public landTypes;
mapping(uint256 => bool) public FreeStable;
ContractGlossary Index;
event LandMinted(
uint256 amount_req,
uint256 indexed _tokenIdCounter,
string landType,
bool freeStable
);
event NContigLandMinted(
uint256 amount_req,
uint256 indexed _tokenIdCounter,
string landType,
bool freeStable
);
constructor(
string memory name,
string memory symbol,
string memory baseTokenURI,
uint256 maxSupply,
address indexContract
) ERC721A(name, symbol) {
_maxSupply = maxSupply;
_baseTokenURI = baseTokenURI;
_tokenIdCounter = 0;
Index = ContractGlossary(indexContract);
}
function pause() external onlyOwner {
_pause();
}
function unpause() external onlyOwner {
_unpause();
}
function mintTransfer(address to, uint256 amount_req)
external
whenNotPaused
{
require(
msg.sender == Index.getAddress("SkyFalls"),
"Must be called from Pyramid Contract"
);
ensureMintConditions(amount_req);
emit LandMinted(amount_req, _tokenIdCounter, "SkyFalls", true);
//Mint number of tokens
for (uint256 i = 1; i <= amount_req; i++) {
landTypes[_tokenIdCounter + i] = "SkyFalls";
FreeStable[_tokenIdCounter + i] = true;
}
_safeMint(to, amount_req);
_tokenIdCounter += amount_req;
}
function setBaseUri(string memory baseUri) external onlyOwner {
_baseTokenURI = baseUri;
}
function mint(
address to,
uint256 amount_req,
string memory landType,
bool freeStable
) external onlyOwner {
ensureMintConditions(amount_req);
emit NContigLandMinted(
amount_req,
_tokenIdCounter,
landType,
freeStable
);
//Mint number of tokens
for (uint256 i = 1; i <= amount_req; i++) {
landTypes[_tokenIdCounter + i] = landType;
FreeStable[_tokenIdCounter + i] = freeStable;
}
_safeMint(to, amount_req);
_tokenIdCounter += amount_req;
}
function eMint(
address to,
uint256 amount_req,
string memory landType,
bool freeStable
) external whenNotPaused {
require(
msg.sender == extMintAddress,
"MUST BE CALLED BY SPECIFIED EXTERNAL MINT ADDRESS"
);
emit NContigLandMinted(
amount_req,
_tokenIdCounter,
landType,
freeStable
);
//Mint number of tokens
for (uint256 i = 1; i <= amount_req; i++) {
landTypes[_tokenIdCounter + i] = landType;
FreeStable[_tokenIdCounter + i] = freeStable;
}
ensureMintConditions(amount_req);
_safeMint(to, amount_req);
_tokenIdCounter += amount_req;
}
function eBurn(uint256 tokenID) public {
require(
msg.sender == extMintAddress,
"MUST BE CALLED BY SPECIFIED EXTERNAL MINT ADDRESS"
);
burn(tokenID);
}
function setExtMintAddress(address contractAddress) public onlyOwner {
require(contractAddress != address(0), "CANNOT BE 0x0 ADDRESS");
extMintAddress = contractAddress;
}
function MAX_TOTAL_MINT() public view returns (uint256) {
return _maxSupply;
}
function _baseURI() internal view virtual override returns (string memory) {
return string(abi.encodePacked(_baseTokenURI));
}
function ensureMintConditions(uint256 count) internal view {
require(totalSupply() + count <= _maxSupply, "EXCEEDS_MAX_SUPPLY");
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/Pausable.sol)
pragma solidity ^0.8.0;
import "Context.sol";
/**
* @dev Contract module which allows children to implement an emergency stop
* mechanism that can be triggered by an authorized account.
*
* This module is used through inheritance. It will make available the
* modifiers `whenNotPaused` and `whenPaused`, which can be applied to
* the functions of your contract. Note that they will not be pausable by
* simply including this module, only once the modifiers are put in place.
*/
abstract contract Pausable is Context {
/**
* @dev Emitted when the pause is triggered by `account`.
*/
event Paused(address account);
/**
* @dev Emitted when the pause is lifted by `account`.
*/
event Unpaused(address account);
bool private _paused;
/**
* @dev Initializes the contract in unpaused state.
*/
constructor() {
_paused = false;
}
/**
* @dev Returns true if the contract is paused, and false otherwise.
*/
function paused() public view virtual returns (bool) {
return _paused;
}
/**
* @dev Modifier to make a function callable only when the contract is not paused.
*
* Requirements:
*
* - The contract must not be paused.
*/
modifier whenNotPaused() {
require(!paused(), "Pausable: paused");
_;
}
/**
* @dev Modifier to make a function callable only when the contract is paused.
*
* Requirements:
*
* - The contract must be paused.
*/
modifier whenPaused() {
require(paused(), "Pausable: not paused");
_;
}
/**
* @dev Triggers stopped state.
*
* Requirements:
*
* - The contract must not be paused.
*/
function _pause() internal virtual whenNotPaused {
_paused = true;
emit Paused(_msgSender());
}
/**
* @dev Returns to normal state.
*
* Requirements:
*
* - The contract must be paused.
*/
function _unpause() internal virtual whenPaused {
_paused = false;
emit Unpaused(_msgSender());
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
// SPDX-License-Identifier: MIT
// ERC721A Contracts v4.2.3
// Creator: Chiru Labs
pragma solidity 0.8.9;
import "IERC721ABurnable.sol";
import "Ownable.sol";
import "ERC721A.sol";
abstract contract ERC721ABurnable is ERC721A, IERC721ABurnable, Ownable {
modifier isWhitelisted(address _addr) {
require(whitelist[_addr], "You need to be whitelisted to burn assets");
_;
}
mapping(address => bool) public whitelist;
function whiteListChange(address _addr, bool isWhiteListed)
public
onlyOwner
{
whitelist[_addr] = isWhiteListed;
}
function burn(uint256 tokenId)
public
virtual
override
isWhitelisted(msg.sender)
{
_burn(tokenId, true);
}
}
// SPDX-License-Identifier: MIT
// ERC721A Contracts v4.2.3
// Creator: Chiru Labs
pragma solidity ^0.8.4;
import "IERC721A.sol";
/**
* @dev Interface of ERC721ABurnable.
*/
interface IERC721ABurnable is IERC721A {
/**
* @dev Burns `tokenId`. See {ERC721A-_burn}.
*
* Requirements:
*
* - The caller must own `tokenId` or be an approved operator.
*/
function burn(uint256 tokenId) external;
}
// SPDX-License-Identifier: MIT
// ERC721A Contracts v4.2.3
// Creator: Chiru Labs
pragma solidity ^0.8.4;
/**
* @dev Interface of ERC721A.
*/
interface IERC721A {
/**
* The caller must own the token or be an approved operator.
*/
error ApprovalCallerNotOwnerNorApproved();
/**
* The token does not exist.
*/
error ApprovalQueryForNonexistentToken();
/**
* Cannot query the balance for the zero address.
*/
error BalanceQueryForZeroAddress();
/**
* Cannot mint to the zero address.
*/
error MintToZeroAddress();
/**
* The quantity of tokens minted must be more than zero.
*/
error MintZeroQuantity();
/**
* The token does not exist.
*/
error OwnerQueryForNonexistentToken();
/**
* The caller must own the token or be an approved operator.
*/
error TransferCallerNotOwnerNorApproved();
/**
* The token must be owned by `from`.
*/
error TransferFromIncorrectOwner();
/**
* Cannot safely transfer to a contract that does not implement the
* ERC721Receiver interface.
*/
error TransferToNonERC721ReceiverImplementer();
/**
* Cannot transfer to the zero address.
*/
error TransferToZeroAddress();
/**
* The token does not exist.
*/
error URIQueryForNonexistentToken();
/**
* The `quantity` minted with ERC2309 exceeds the safety limit.
*/
error MintERC2309QuantityExceedsLimit();
/**
* The `extraData` cannot be set on an unintialized ownership slot.
*/
error OwnershipNotInitializedForExtraData();
// =============================================================
// STRUCTS
// =============================================================
struct TokenOwnership {
// The address of the owner.
address addr;
// Stores the start time of ownership with minimal overhead for tokenomics.
uint64 startTimestamp;
// Whether the token has been burned.
bool burned;
// Arbitrary data similar to `startTimestamp` that can be set via {_extraData}.
uint24 extraData;
}
// =============================================================
// TOKEN COUNTERS
// =============================================================
/**
* @dev Returns the total number of tokens in existence.
* Burned tokens will reduce the count.
* To get the total number of tokens minted, please see {_totalMinted}.
*/
function totalSupply() external view returns (uint256);
// =============================================================
// IERC165
// =============================================================
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)
* to learn more about how these ids are created.
*
* This function call must use less than 30000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
// =============================================================
// IERC721
// =============================================================
/**
* @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`,
* 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 be 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,
bytes calldata data
) external payable;
/**
* @dev Equivalent to `safeTransferFrom(from, to, tokenId, '')`.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) external payable;
/**
* @dev Transfers `tokenId` from `from` to `to`.
*
* WARNING: Usage of this method is discouraged, use {safeTransferFrom}
* whenever possible.
*
* 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 payable;
/**
* @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 payable;
/**
* @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);
// =============================================================
// IERC721Metadata
// =============================================================
/**
* @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);
// =============================================================
// IERC2309
// =============================================================
/**
* @dev Emitted when tokens in `fromTokenId` to `toTokenId`
* (inclusive) is transferred from `from` to `to`, as defined in the
* [ERC2309](https://eips.ethereum.org/EIPS/eip-2309) standard.
*
* See {_mintERC2309} for more details.
*/
event ConsecutiveTransfer(
uint256 indexed fromTokenId,
uint256 toTokenId,
address indexed from,
address indexed to
);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)
pragma solidity ^0.8.0;
import "Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() {
_transferOwnership(_msgSender());
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// SPDX-License-Identifier: MIT
// ERC721A Contracts v4.2.3
// Creator: Chiru Labs
pragma solidity ^0.8.4;
import "IERC721A.sol";
/**
* @dev Interface of ERC721 token receiver.
*/
interface ERC721A__IERC721Receiver {
function onERC721Received(
address operator,
address from,
uint256 tokenId,
bytes calldata data
) external returns (bytes4);
}
/**
* @title ERC721A
*
* @dev Implementation of the [ERC721](https://eips.ethereum.org/EIPS/eip-721)
* Non-Fungible Token Standard, including the Metadata extension.
* Optimized for lower gas during batch mints.
*
* Token IDs are minted in sequential order (e.g. 0, 1, 2, 3, ...)
* starting from `_startTokenId()`.
*
* Assumptions:
*
* - An owner cannot have more than 2**64 - 1 (max value of uint64) of supply.
* - The maximum token ID cannot exceed 2**256 - 1 (max value of uint256).
*/
contract ERC721A is IERC721A {
// Bypass for a `--via-ir` bug (https://github.com/chiru-labs/ERC721A/pull/364).
struct TokenApprovalRef {
address value;
}
// =============================================================
// CONSTANTS
// =============================================================
// Mask of an entry in packed address data.
uint256 private constant _BITMASK_ADDRESS_DATA_ENTRY = (1 << 64) - 1;
// The bit position of `numberMinted` in packed address data.
uint256 private constant _BITPOS_NUMBER_MINTED = 64;
// The bit position of `numberBurned` in packed address data.
uint256 private constant _BITPOS_NUMBER_BURNED = 128;
// The bit position of `aux` in packed address data.
uint256 private constant _BITPOS_AUX = 192;
// Mask of all 256 bits in packed address data except the 64 bits for `aux`.
uint256 private constant _BITMASK_AUX_COMPLEMENT = (1 << 192) - 1;
// The bit position of `startTimestamp` in packed ownership.
uint256 private constant _BITPOS_START_TIMESTAMP = 160;
// The bit mask of the `burned` bit in packed ownership.
uint256 private constant _BITMASK_BURNED = 1 << 224;
// The bit position of the `nextInitialized` bit in packed ownership.
uint256 private constant _BITPOS_NEXT_INITIALIZED = 225;
// The bit mask of the `nextInitialized` bit in packed ownership.
uint256 private constant _BITMASK_NEXT_INITIALIZED = 1 << 225;
// The bit position of `extraData` in packed ownership.
uint256 private constant _BITPOS_EXTRA_DATA = 232;
// Mask of all 256 bits in a packed ownership except the 24 bits for `extraData`.
uint256 private constant _BITMASK_EXTRA_DATA_COMPLEMENT = (1 << 232) - 1;
// The mask of the lower 160 bits for addresses.
uint256 private constant _BITMASK_ADDRESS = (1 << 160) - 1;
// The maximum `quantity` that can be minted with {_mintERC2309}.
// This limit is to prevent overflows on the address data entries.
// For a limit of 5000, a total of 3.689e15 calls to {_mintERC2309}
// is required to cause an overflow, which is unrealistic.
uint256 private constant _MAX_MINT_ERC2309_QUANTITY_LIMIT = 5000;
// The `Transfer` event signature is given by:
// `keccak256(bytes("Transfer(address,address,uint256)"))`.
bytes32 private constant _TRANSFER_EVENT_SIGNATURE =
0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef;
// =============================================================
// STORAGE
// =============================================================
// The next token ID to be minted.
uint256 private _currentIndex;
// The number of tokens burned.
uint256 private _burnCounter;
// Token name
string private _name;
// Token symbol
string private _symbol;
// Mapping from token ID to ownership details
// An empty struct value does not necessarily mean the token is unowned.
// See {_packedOwnershipOf} implementation for details.
//
// Bits Layout:
// - [0..159] `addr`
// - [160..223] `startTimestamp`
// - [224] `burned`
// - [225] `nextInitialized`
// - [232..255] `extraData`
mapping(uint256 => uint256) private _packedOwnerships;
// Mapping owner address to address data.
//
// Bits Layout:
// - [0..63] `balance`
// - [64..127] `numberMinted`
// - [128..191] `numberBurned`
// - [192..255] `aux`
mapping(address => uint256) private _packedAddressData;
// Mapping from token ID to approved address.
mapping(uint256 => TokenApprovalRef) private _tokenApprovals;
// Mapping from owner to operator approvals
mapping(address => mapping(address => bool)) private _operatorApprovals;
// =============================================================
// CONSTRUCTOR
// =============================================================
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
_currentIndex = _startTokenId();
}
// =============================================================
// TOKEN COUNTING OPERATIONS
// =============================================================
/**
* @dev Returns the starting token ID.
* To change the starting token ID, please override this function.
*/
function _startTokenId() internal view virtual returns (uint256) {
return 0;
}
/**
* @dev Returns the next token ID to be minted.
*/
function _nextTokenId() internal view virtual returns (uint256) {
return _currentIndex;
}
/**
* @dev Returns the total number of tokens in existence.
* Burned tokens will reduce the count.
* To get the total number of tokens minted, please see {_totalMinted}.
*/
function totalSupply() public view virtual override returns (uint256) {
// Counter underflow is impossible as _burnCounter cannot be incremented
// more than `_currentIndex - _startTokenId()` times.
unchecked {
return _currentIndex - _burnCounter - _startTokenId();
}
}
/**
* @dev Returns the total amount of tokens minted in the contract.
*/
function _totalMinted() internal view virtual returns (uint256) {
// Counter underflow is impossible as `_currentIndex` does not decrement,
// and it is initialized to `_startTokenId()`.
unchecked {
return _currentIndex - _startTokenId();
}
}
/**
* @dev Returns the total number of tokens burned.
*/
function _totalBurned() internal view virtual returns (uint256) {
return _burnCounter;
}
// =============================================================
// ADDRESS DATA OPERATIONS
// =============================================================
/**
* @dev Returns the number of tokens in `owner`'s account.
*/
function balanceOf(address owner)
public
view
virtual
override
returns (uint256)
{
if (owner == address(0)) revert BalanceQueryForZeroAddress();
return _packedAddressData[owner] & _BITMASK_ADDRESS_DATA_ENTRY;
}
/**
* Returns the number of tokens minted by `owner`.
*/
function _numberMinted(address owner) internal view returns (uint256) {
return
(_packedAddressData[owner] >> _BITPOS_NUMBER_MINTED) &
_BITMASK_ADDRESS_DATA_ENTRY;
}
/**
* Returns the number of tokens burned by or on behalf of `owner`.
*/
function _numberBurned(address owner) internal view returns (uint256) {
return
(_packedAddressData[owner] >> _BITPOS_NUMBER_BURNED) &
_BITMASK_ADDRESS_DATA_ENTRY;
}
/**
* Returns the auxiliary data for `owner`. (e.g. number of whitelist mint slots used).
*/
function _getAux(address owner) internal view returns (uint64) {
return uint64(_packedAddressData[owner] >> _BITPOS_AUX);
}
/**
* Sets the auxiliary data for `owner`. (e.g. number of whitelist mint slots used).
* If there are multiple variables, please pack them into a uint64.
*/
function _setAux(address owner, uint64 aux) internal virtual {
uint256 packed = _packedAddressData[owner];
uint256 auxCasted;
// Cast `aux` with assembly to avoid redundant masking.
assembly {
auxCasted := aux
}
packed =
(packed & _BITMASK_AUX_COMPLEMENT) |
(auxCasted << _BITPOS_AUX);
_packedAddressData[owner] = packed;
}
// =============================================================
// IERC165
// =============================================================
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)
* to learn more about how these ids are created.
*
* This function call must use less than 30000 gas.
*/
function supportsInterface(bytes4 interfaceId)
public
view
virtual
override
returns (bool)
{
// The interface IDs are constants representing the first 4 bytes
// of the XOR of all function selectors in the interface.
// See: [ERC165](https://eips.ethereum.org/EIPS/eip-165)
// (e.g. `bytes4(i.functionA.selector ^ i.functionB.selector ^ ...)`)
return
interfaceId == 0x01ffc9a7 || // ERC165 interface ID for ERC165.
interfaceId == 0x80ac58cd || // ERC165 interface ID for ERC721.
interfaceId == 0x5b5e139f; // ERC165 interface ID for ERC721Metadata.
}
// =============================================================
// IERC721Metadata
// =============================================================
/**
* @dev Returns the token collection name.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev Returns the token collection symbol.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
/**
* @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
*/
function tokenURI(uint256 tokenId)
public
view
virtual
override
returns (string memory)
{
if (!_exists(tokenId)) revert URIQueryForNonexistentToken();
string memory baseURI = _baseURI();
return
bytes(baseURI).length != 0
? string(abi.encodePacked(baseURI, _toString(tokenId)))
: "";
}
/**
* @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, it can be overridden in child contracts.
*/
function _baseURI() internal view virtual returns (string memory) {
return "";
}
// =============================================================
// OWNERSHIPS OPERATIONS
// =============================================================
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function ownerOf(uint256 tokenId)
public
view
virtual
override
returns (address)
{
return address(uint160(_packedOwnershipOf(tokenId)));
}
/**
* @dev Gas spent here starts off proportional to the maximum mint batch size.
* It gradually moves to O(1) as tokens get transferred around over time.
*/
function _ownershipOf(uint256 tokenId)
internal
view
virtual
returns (TokenOwnership memory)
{
return _unpackedOwnership(_packedOwnershipOf(tokenId));
}
/**
* @dev Returns the unpacked `TokenOwnership` struct at `index`.
*/
function _ownershipAt(uint256 index)
internal
view
virtual
returns (TokenOwnership memory)
{
return _unpackedOwnership(_packedOwnerships[index]);
}
/**
* @dev Initializes the ownership slot minted at `index` for efficiency purposes.
*/
function _initializeOwnershipAt(uint256 index) internal virtual {
if (_packedOwnerships[index] == 0) {
_packedOwnerships[index] = _packedOwnershipOf(index);
}
}
/**
* Returns the packed ownership data of `tokenId`.
*/
function _packedOwnershipOf(uint256 tokenId)
private
view
returns (uint256 packed)
{
if (_startTokenId() <= tokenId) {
packed = _packedOwnerships[tokenId];
// If not burned.
if (packed & _BITMASK_BURNED == 0) {
// If the data at the starting slot does not exist, start the scan.
if (packed == 0) {
if (tokenId >= _currentIndex)
revert OwnerQueryForNonexistentToken();
// Invariant:
// There will always be an initialized ownership slot
// (i.e. `ownership.addr != address(0) && ownership.burned == false`)
// before an unintialized ownership slot
// (i.e. `ownership.addr == address(0) && ownership.burned == false`)
// Hence, `tokenId` will not underflow.
//
// We can directly compare the packed value.
// If the address is zero, packed will be zero.
for (;;) {
unchecked {
packed = _packedOwnerships[--tokenId];
}
if (packed == 0) continue;
return packed;
}
}
// Otherwise, the data exists and is not burned. We can skip the scan.
// This is possible because we have already achieved the target condition.
// This saves 2143 gas on transfers of initialized tokens.
return packed;
}
}
revert OwnerQueryForNonexistentToken();
}
/**
* @dev Returns the unpacked `TokenOwnership` struct from `packed`.
*/
function _unpackedOwnership(uint256 packed)
private
pure
returns (TokenOwnership memory ownership)
{
ownership.addr = address(uint160(packed));
ownership.startTimestamp = uint64(packed >> _BITPOS_START_TIMESTAMP);
ownership.burned = packed & _BITMASK_BURNED != 0;
ownership.extraData = uint24(packed >> _BITPOS_EXTRA_DATA);
}
/**
* @dev Packs ownership data into a single uint256.
*/
function _packOwnershipData(address owner, uint256 flags)
private
view
returns (uint256 result)
{
assembly {
// Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.
owner := and(owner, _BITMASK_ADDRESS)
// `owner | (block.timestamp << _BITPOS_START_TIMESTAMP) | flags`.
result := or(
owner,
or(shl(_BITPOS_START_TIMESTAMP, timestamp()), flags)
)
}
}
/**
* @dev Returns the `nextInitialized` flag set if `quantity` equals 1.
*/
function _nextInitializedFlag(uint256 quantity)
private
pure
returns (uint256 result)
{
// For branchless setting of the `nextInitialized` flag.
assembly {
// `(quantity == 1) << _BITPOS_NEXT_INITIALIZED`.
result := shl(_BITPOS_NEXT_INITIALIZED, eq(quantity, 1))
}
}
// =============================================================
// APPROVAL OPERATIONS
// =============================================================
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account. See {ERC721A-_approve}.
*
* Requirements:
*
* - The caller must own the token or be an approved operator.
*/
function approve(address to, uint256 tokenId)
public
payable
virtual
override
{
_approve(to, tokenId, true);
}
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function getApproved(uint256 tokenId)
public
view
virtual
override
returns (address)
{
if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();
return _tokenApprovals[tokenId].value;
}
/**
* @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)
public
virtual
override
{
_operatorApprovals[_msgSenderERC721A()][operator] = approved;
emit ApprovalForAll(_msgSenderERC721A(), operator, approved);
}
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}.
*/
function isApprovedForAll(address owner, address operator)
public
view
virtual
override
returns (bool)
{
return _operatorApprovals[owner][operator];
}
/**
* @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. See {_mint}.
*/
function _exists(uint256 tokenId) internal view virtual returns (bool) {
return
_startTokenId() <= tokenId &&
tokenId < _currentIndex && // If within bounds,
_packedOwnerships[tokenId] & _BITMASK_BURNED == 0; // and not burned.
}
/**
* @dev Returns whether `msgSender` is equal to `approvedAddress` or `owner`.
*/
function _isSenderApprovedOrOwner(
address approvedAddress,
address owner,
address msgSender
) private pure returns (bool result) {
assembly {
// Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.
owner := and(owner, _BITMASK_ADDRESS)
// Mask `msgSender` to the lower 160 bits, in case the upper bits somehow aren't clean.
msgSender := and(msgSender, _BITMASK_ADDRESS)
// `msgSender == owner || msgSender == approvedAddress`.
result := or(eq(msgSender, owner), eq(msgSender, approvedAddress))
}
}
/**
* @dev Returns the storage slot and value for the approved address of `tokenId`.
*/
function _getApprovedSlotAndAddress(uint256 tokenId)
private
view
returns (uint256 approvedAddressSlot, address approvedAddress)
{
TokenApprovalRef storage tokenApproval = _tokenApprovals[tokenId];
// The following is equivalent to `approvedAddress = _tokenApprovals[tokenId].value`.
assembly {
approvedAddressSlot := tokenApproval.slot
approvedAddress := sload(approvedAddressSlot)
}
}
// =============================================================
// TRANSFER OPERATIONS
// =============================================================
/**
* @dev Transfers `tokenId` from `from` to `to`.
*
* 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
) public payable virtual override {
uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);
if (address(uint160(prevOwnershipPacked)) != from)
revert TransferFromIncorrectOwner();
(
uint256 approvedAddressSlot,
address approvedAddress
) = _getApprovedSlotAndAddress(tokenId);
// The nested ifs save around 20+ gas over a compound boolean condition.
if (
!_isSenderApprovedOrOwner(
approvedAddress,
from,
_msgSenderERC721A()
)
)
if (!isApprovedForAll(from, _msgSenderERC721A()))
revert TransferCallerNotOwnerNorApproved();
if (to == address(0)) revert TransferToZeroAddress();
_beforeTokenTransfers(from, to, tokenId, 1);
// Clear approvals from the previous owner.
assembly {
if approvedAddress {
// This is equivalent to `delete _tokenApprovals[tokenId]`.
sstore(approvedAddressSlot, 0)
}
}
// Underflow of the sender's balance is impossible because we check for
// ownership above and the recipient's balance can't realistically overflow.
// Counter overflow is incredibly unrealistic as `tokenId` would have to be 2**256.
unchecked {
// We can directly increment and decrement the balances.
--_packedAddressData[from]; // Updates: `balance -= 1`.
++_packedAddressData[to]; // Updates: `balance += 1`.
// Updates:
// - `address` to the next owner.
// - `startTimestamp` to the timestamp of transfering.
// - `burned` to `false`.
// - `nextInitialized` to `true`.
_packedOwnerships[tokenId] = _packOwnershipData(
to,
_BITMASK_NEXT_INITIALIZED |
_nextExtraData(from, to, prevOwnershipPacked)
);
// If the next slot may not have been initialized (i.e. `nextInitialized == false`) .
if (prevOwnershipPacked & _BITMASK_NEXT_INITIALIZED == 0) {
uint256 nextTokenId = tokenId + 1;
// If the next slot's address is zero and not burned (i.e. packed value is zero).
if (_packedOwnerships[nextTokenId] == 0) {
// If the next slot is within bounds.
if (nextTokenId != _currentIndex) {
// Initialize the next slot to maintain correctness for `ownerOf(tokenId + 1)`.
_packedOwnerships[nextTokenId] = prevOwnershipPacked;
}
}
}
}
emit Transfer(from, to, tokenId);
_afterTokenTransfers(from, to, tokenId, 1);
}
/**
* @dev Equivalent to `safeTransferFrom(from, to, tokenId, '')`.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) public payable virtual override {
safeTransferFrom(from, to, tokenId, "");
}
/**
* @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 memory _data
) public payable virtual override {
transferFrom(from, to, tokenId);
if (to.code.length != 0)
if (!_checkContractOnERC721Received(from, to, tokenId, _data)) {
revert TransferToNonERC721ReceiverImplementer();
}
}
/**
* @dev Hook that is called before a set of serially-ordered token IDs
* are about to be transferred. This includes minting.
* And also called before burning one token.
*
* `startTokenId` - the first token ID to be transferred.
* `quantity` - the amount to be transferred.
*
* Calling conditions:
*
* - When `from` and `to` are both non-zero, `from`'s `tokenId` will be
* transferred to `to`.
* - When `from` is zero, `tokenId` will be minted for `to`.
* - When `to` is zero, `tokenId` will be burned by `from`.
* - `from` and `to` are never both zero.
*/
function _beforeTokenTransfers(
address from,
address to,
uint256 startTokenId,
uint256 quantity
) internal virtual {}
/**
* @dev Hook that is called after a set of serially-ordered token IDs
* have been transferred. This includes minting.
* And also called after one token has been burned.
*
* `startTokenId` - the first token ID to be transferred.
* `quantity` - the amount to be transferred.
*
* Calling conditions:
*
* - When `from` and `to` are both non-zero, `from`'s `tokenId` has been
* transferred to `to`.
* - When `from` is zero, `tokenId` has been minted for `to`.
* - When `to` is zero, `tokenId` has been burned by `from`.
* - `from` and `to` are never both zero.
*/
function _afterTokenTransfers(
address from,
address to,
uint256 startTokenId,
uint256 quantity
) internal virtual {}
/**
* @dev Private function to invoke {IERC721Receiver-onERC721Received} on a target contract.
*
* `from` - Previous owner of the given token ID.
* `to` - Target address that will receive the token.
* `tokenId` - Token ID to be transferred.
* `_data` - Optional data to send along with the call.
*
* Returns whether the call correctly returned the expected magic value.
*/
function _checkContractOnERC721Received(
address from,
address to,
uint256 tokenId,
bytes memory _data
) private returns (bool) {
try
ERC721A__IERC721Receiver(to).onERC721Received(
_msgSenderERC721A(),
from,
tokenId,
_data
)
returns (bytes4 retval) {
return
retval ==
ERC721A__IERC721Receiver(to).onERC721Received.selector;
} catch (bytes memory reason) {
if (reason.length == 0) {
revert TransferToNonERC721ReceiverImplementer();
} else {
assembly {
revert(add(32, reason), mload(reason))
}
}
}
}
// =============================================================
// MINT OPERATIONS
// =============================================================
/**
* @dev Mints `quantity` tokens and transfers them to `to`.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - `quantity` must be greater than 0.
*
* Emits a {Transfer} event for each mint.
*/
function _mint(address to, uint256 quantity) internal virtual {
uint256 startTokenId = _currentIndex;
if (quantity == 0) revert MintZeroQuantity();
_beforeTokenTransfers(address(0), to, startTokenId, quantity);
// Overflows are incredibly unrealistic.
// `balance` and `numberMinted` have a maximum limit of 2**64.
// `tokenId` has a maximum limit of 2**256.
unchecked {
// Updates:
// - `balance += quantity`.
// - `numberMinted += quantity`.
//
// We can directly add to the `balance` and `numberMinted`.
_packedAddressData[to] +=
quantity *
((1 << _BITPOS_NUMBER_MINTED) | 1);
// Updates:
// - `address` to the owner.
// - `startTimestamp` to the timestamp of minting.
// - `burned` to `false`.
// - `nextInitialized` to `quantity == 1`.
_packedOwnerships[startTokenId] = _packOwnershipData(
to,
_nextInitializedFlag(quantity) |
_nextExtraData(address(0), to, 0)
);
uint256 toMasked;
uint256 end = startTokenId + quantity;
// Use assembly to loop and emit the `Transfer` event for gas savings.
// The duplicated `log4` removes an extra check and reduces stack juggling.
// The assembly, together with the surrounding Solidity code, have been
// delicately arranged to nudge the compiler into producing optimized opcodes.
assembly {
// Mask `to` to the lower 160 bits, in case the upper bits somehow aren't clean.
toMasked := and(to, _BITMASK_ADDRESS)
// Emit the `Transfer` event.
log4(
0, // Start of data (0, since no data).
0, // End of data (0, since no data).
_TRANSFER_EVENT_SIGNATURE, // Signature.
0, // `address(0)`.
toMasked, // `to`.
startTokenId // `tokenId`.
)
// The `iszero(eq(,))` check ensures that large values of `quantity`
// that overflows uint256 will make the loop run out of gas.
// The compiler will optimize the `iszero` away for performance.
for {
let tokenId := add(startTokenId, 1)
} iszero(eq(tokenId, end)) {
tokenId := add(tokenId, 1)
} {
// Emit the `Transfer` event. Similar to above.
log4(0, 0, _TRANSFER_EVENT_SIGNATURE, 0, toMasked, tokenId)
}
}
if (toMasked == 0) revert MintToZeroAddress();
_currentIndex = end;
}
_afterTokenTransfers(address(0), to, startTokenId, quantity);
}
/**
* @dev Mints `quantity` tokens and transfers them to `to`.
*
* This function is intended for efficient minting only during contract creation.
*
* It emits only one {ConsecutiveTransfer} as defined in
* [ERC2309](https://eips.ethereum.org/EIPS/eip-2309),
* instead of a sequence of {Transfer} event(s).
*
* Calling this function outside of contract creation WILL make your contract
* non-compliant with the ERC721 standard.
* For full ERC721 compliance, substituting ERC721 {Transfer} event(s) with the ERC2309
* {ConsecutiveTransfer} event is only permissible during contract creation.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - `quantity` must be greater than 0.
*
* Emits a {ConsecutiveTransfer} event.
*/
function _mintERC2309(address to, uint256 quantity) internal virtual {
uint256 startTokenId = _currentIndex;
if (to == address(0)) revert MintToZeroAddress();
if (quantity == 0) revert MintZeroQuantity();
if (quantity > _MAX_MINT_ERC2309_QUANTITY_LIMIT)
revert MintERC2309QuantityExceedsLimit();
_beforeTokenTransfers(address(0), to, startTokenId, quantity);
// Overflows are unrealistic due to the above check for `quantity` to be below the limit.
unchecked {
// Updates:
// - `balance += quantity`.
// - `numberMinted += quantity`.
//
// We can directly add to the `balance` and `numberMinted`.
_packedAddressData[to] +=
quantity *
((1 << _BITPOS_NUMBER_MINTED) | 1);
// Updates:
// - `address` to the owner.
// - `startTimestamp` to the timestamp of minting.
// - `burned` to `false`.
// - `nextInitialized` to `quantity == 1`.
_packedOwnerships[startTokenId] = _packOwnershipData(
to,
_nextInitializedFlag(quantity) |
_nextExtraData(address(0), to, 0)
);
emit ConsecutiveTransfer(
startTokenId,
startTokenId + quantity - 1,
address(0),
to
);
_currentIndex = startTokenId + quantity;
}
_afterTokenTransfers(address(0), to, startTokenId, quantity);
}
/**
* @dev Safely mints `quantity` tokens and transfers them to `to`.
*
* Requirements:
*
* - If `to` refers to a smart contract, it must implement
* {IERC721Receiver-onERC721Received}, which is called for each safe transfer.
* - `quantity` must be greater than 0.
*
* See {_mint}.
*
* Emits a {Transfer} event for each mint.
*/
function _safeMint(
address to,
uint256 quantity,
bytes memory _data
) internal virtual {
_mint(to, quantity);
unchecked {
if (to.code.length != 0) {
uint256 end = _currentIndex;
uint256 index = end - quantity;
do {
if (
!_checkContractOnERC721Received(
address(0),
to,
index++,
_data
)
) {
revert TransferToNonERC721ReceiverImplementer();
}
} while (index < end);
// Reentrancy protection.
if (_currentIndex != end) revert();
}
}
}
/**
* @dev Equivalent to `_safeMint(to, quantity, '')`.
*/
function _safeMint(address to, uint256 quantity) internal virtual {
_safeMint(to, quantity, "");
}
// =============================================================
// APPROVAL OPERATIONS
// =============================================================
/**
* @dev Equivalent to `_approve(to, tokenId, false)`.
*/
function _approve(address to, uint256 tokenId) internal virtual {
_approve(to, tokenId, false);
}
/**
* @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:
*
* - `tokenId` must exist.
*
* Emits an {Approval} event.
*/
function _approve(
address to,
uint256 tokenId,
bool approvalCheck
) internal virtual {
address owner = ownerOf(tokenId);
if (approvalCheck)
if (_msgSenderERC721A() != owner)
if (!isApprovedForAll(owner, _msgSenderERC721A())) {
revert ApprovalCallerNotOwnerNorApproved();
}
_tokenApprovals[tokenId].value = to;
emit Approval(owner, to, tokenId);
}
// =============================================================
// BURN OPERATIONS
// =============================================================
/**
* @dev Equivalent to `_burn(tokenId, false)`.
*/
function _burn(uint256 tokenId) internal virtual {
_burn(tokenId, false);
}
/**
* @dev Destroys `tokenId`.
* The approval is cleared when the token is burned.
*
* Requirements:
*
* - `tokenId` must exist.
*
* Emits a {Transfer} event.
*/
function _burn(uint256 tokenId, bool approvalCheck) internal virtual {
uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);
address from = address(uint160(prevOwnershipPacked));
(
uint256 approvedAddressSlot,
address approvedAddress
) = _getApprovedSlotAndAddress(tokenId);
if (approvalCheck) {
// The nested ifs save around 20+ gas over a compound boolean condition.
if (
!_isSenderApprovedOrOwner(
approvedAddress,
from,
_msgSenderERC721A()
)
)
if (!isApprovedForAll(from, _msgSenderERC721A()))
revert TransferCallerNotOwnerNorApproved();
}
_beforeTokenTransfers(from, address(0), tokenId, 1);
// Clear approvals from the previous owner.
assembly {
if approvedAddress {
// This is equivalent to `delete _tokenApprovals[tokenId]`.
sstore(approvedAddressSlot, 0)
}
}
// Underflow of the sender's balance is impossible because we check for
// ownership above and the recipient's balance can't realistically overflow.
// Counter overflow is incredibly unrealistic as `tokenId` would have to be 2**256.
unchecked {
// Updates:
// - `balance -= 1`.
// - `numberBurned += 1`.
//
// We can directly decrement the balance, and increment the number burned.
// This is equivalent to `packed -= 1; packed += 1 << _BITPOS_NUMBER_BURNED;`.
_packedAddressData[from] += (1 << _BITPOS_NUMBER_BURNED) - 1;
// Updates:
// - `address` to the last owner.
// - `startTimestamp` to the timestamp of burning.
// - `burned` to `true`.
// - `nextInitialized` to `true`.
_packedOwnerships[tokenId] = _packOwnershipData(
from,
(_BITMASK_BURNED | _BITMASK_NEXT_INITIALIZED) |
_nextExtraData(from, address(0), prevOwnershipPacked)
);
// If the next slot may not have been initialized (i.e. `nextInitialized == false`) .
if (prevOwnershipPacked & _BITMASK_NEXT_INITIALIZED == 0) {
uint256 nextTokenId = tokenId + 1;
// If the next slot's address is zero and not burned (i.e. packed value is zero).
if (_packedOwnerships[nextTokenId] == 0) {
// If the next slot is within bounds.
if (nextTokenId != _currentIndex) {
// Initialize the next slot to maintain correctness for `ownerOf(tokenId + 1)`.
_packedOwnerships[nextTokenId] = prevOwnershipPacked;
}
}
}
}
emit Transfer(from, address(0), tokenId);
_afterTokenTransfers(from, address(0), tokenId, 1);
// Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.
unchecked {
_burnCounter++;
}
}
// =============================================================
// EXTRA DATA OPERATIONS
// =============================================================
/**
* @dev Directly sets the extra data for the ownership data `index`.
*/
function _setExtraDataAt(uint256 index, uint24 extraData) internal virtual {
uint256 packed = _packedOwnerships[index];
if (packed == 0) revert OwnershipNotInitializedForExtraData();
uint256 extraDataCasted;
// Cast `extraData` with assembly to avoid redundant masking.
assembly {
extraDataCasted := extraData
}
packed =
(packed & _BITMASK_EXTRA_DATA_COMPLEMENT) |
(extraDataCasted << _BITPOS_EXTRA_DATA);
_packedOwnerships[index] = packed;
}
/**
* @dev Called during each token transfer to set the 24bit `extraData` field.
* Intended to be overridden by the cosumer contract.
*
* `previousExtraData` - the value of `extraData` before transfer.
*
* Calling conditions:
*
* - When `from` and `to` are both non-zero, `from`'s `tokenId` will be
* transferred to `to`.
* - When `from` is zero, `tokenId` will be minted for `to`.
* - When `to` is zero, `tokenId` will be burned by `from`.
* - `from` and `to` are never both zero.
*/
function _extraData(
address from,
address to,
uint24 previousExtraData
) internal view virtual returns (uint24) {}
/**
* @dev Returns the next extra data for the packed ownership data.
* The returned result is shifted into position.
*/
function _nextExtraData(
address from,
address to,
uint256 prevOwnershipPacked
) private view returns (uint256) {
uint24 extraData = uint24(prevOwnershipPacked >> _BITPOS_EXTRA_DATA);
return uint256(_extraData(from, to, extraData)) << _BITPOS_EXTRA_DATA;
}
// =============================================================
// OTHER OPERATIONS
// =============================================================
/**
* @dev Returns the message sender (defaults to `msg.sender`).
*
* If you are writing GSN compatible contracts, you need to override this function.
*/
function _msgSenderERC721A() internal view virtual returns (address) {
return msg.sender;
}
/**
* @dev Converts a uint256 to its ASCII string decimal representation.
*/
function _toString(uint256 value)
internal
pure
virtual
returns (string memory str)
{
assembly {
// The maximum value of a uint256 contains 78 digits (1 byte per digit), but
// we allocate 0xa0 bytes to keep the free memory pointer 32-byte word aligned.
// We will need 1 word for the trailing zeros padding, 1 word for the length,
// and 3 words for a maximum of 78 digits. Total: 5 * 0x20 = 0xa0.
let m := add(mload(0x40), 0xa0)
// Update the free memory pointer to allocate.
mstore(0x40, m)
// Assign the `str` to the end.
str := sub(m, 0x20)
// Zeroize the slot after the string.
mstore(str, 0)
// Cache the end of the memory to calculate the length later.
let end := str
// We write the string from rightmost digit to leftmost digit.
// The following is essentially a do-while loop that also handles the zero case.
// prettier-ignore
for { let temp := value } 1 {} {
str := sub(str, 1)
// Write the character to the pointer.
// The ASCII index of the '0' character is 48.
mstore8(str, add(48, mod(temp, 10)))
// Keep dividing `temp` until zero.
temp := div(temp, 10)
// prettier-ignore
if iszero(temp) { break }
}
let length := sub(end, str)
// Move the pointer 32 bytes leftwards to make room for the length.
str := sub(str, 0x20)
// Store the length.
mstore(str, length)
}
}
}