forked from DecentralizedClimateFoundation/DCIPs
616 lines
21 KiB
Solidity
616 lines
21 KiB
Solidity
// SPDX-License-Identifier: CC0-1.0
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// Creator: Chiru Labs
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pragma solidity ^0.8.4;
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import '@openzeppelin/contracts/token/ERC721/IERC721.sol';
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import '@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol';
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import '@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol';
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import '@openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol';
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import '@openzeppelin/contracts/utils/Address.sol';
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import '@openzeppelin/contracts/utils/Context.sol';
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import '@openzeppelin/contracts/utils/Strings.sol';
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import '@openzeppelin/contracts/utils/introspection/ERC165.sol';
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error ApprovalCallerNotOwnerNorApproved();
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error ApprovalQueryForNonexistentToken();
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error ApproveToCaller();
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error ApprovalToCurrentOwner();
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error BalanceQueryForZeroAddress();
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error MintedQueryForZeroAddress();
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error BurnedQueryForZeroAddress();
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error AuxQueryForZeroAddress();
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error MintToZeroAddress();
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error MintZeroQuantity();
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error OwnerIndexOutOfBounds();
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error OwnerQueryForNonexistentToken();
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error TokenIndexOutOfBounds();
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error TransferCallerNotOwnerNorApproved();
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error TransferFromIncorrectOwner();
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error TransferToNonERC721ReceiverImplementer();
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error TransferToZeroAddress();
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error URIQueryForNonexistentToken();
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/**
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* @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
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* the Metadata extension. Built to optimize for lower gas during batch mints.
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*
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* Assumes serials are sequentially minted starting at _startTokenId() (defaults to 0, e.g. 0, 1, 2, 3..).
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*
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* Assumes that an owner cannot have more than 2**64 - 1 (max value of uint64) of supply.
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*
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* Assumes that the maximum token id cannot exceed 2**256 - 1 (max value of uint256).
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*/
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contract ERC721A is Context, ERC165, IERC721, IERC721Metadata {
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using Address for address;
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using Strings for uint256;
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// Compiler will pack this into a single 256bit word.
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struct TokenOwnership {
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// The address of the owner.
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address addr;
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// Keeps track of the start time of ownership with minimal overhead for tokenomics.
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uint64 startTimestamp;
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// Whether the token has been burned.
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bool burned;
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}
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// Compiler will pack this into a single 256bit word.
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struct AddressData {
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// Realistically, 2**64-1 is more than enough.
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uint64 balance;
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// Keeps track of mint count with minimal overhead for tokenomics.
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uint64 numberMinted;
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// Keeps track of burn count with minimal overhead for tokenomics.
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uint64 numberBurned;
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// For miscellaneous variable(s) pertaining to the address
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// (e.g. number of whitelist mint slots used).
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// If there are multiple variables, please pack them into a uint64.
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uint64 aux;
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}
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// The tokenId of the next token to be minted.
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uint256 internal _currentIndex;
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// The number of tokens burned.
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uint256 internal _burnCounter;
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// Token name
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string private _name;
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// Token symbol
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string private _symbol;
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// Mapping from token ID to ownership details
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// An empty struct value does not necessarily mean the token is unowned. See ownershipOf implementation for details.
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mapping(uint256 => TokenOwnership) internal _ownerships;
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// Mapping owner address to address data
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mapping(address => AddressData) private _addressData;
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// Mapping from token ID to approved address
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mapping(uint256 => address) private _tokenApprovals;
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// Mapping from owner to operator approvals
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mapping(address => mapping(address => bool)) private _operatorApprovals;
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constructor(string memory name_, string memory symbol_) {
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_name = name_;
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_symbol = symbol_;
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_currentIndex = _startTokenId();
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}
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/**
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* To change the starting tokenId, please override this function.
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*/
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function _startTokenId() internal view virtual returns (uint256) {
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return 0;
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}
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/**
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* @dev See {IERC721Enumerable-totalSupply}.
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* @dev Burned tokens are calculated here, use _totalMinted() if you want to count just minted tokens.
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*/
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function totalSupply() public view returns (uint256) {
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// Counter underflow is impossible as _burnCounter cannot be incremented
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// more than _currentIndex - _startTokenId() times
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unchecked {
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return _currentIndex - _burnCounter - _startTokenId();
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}
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}
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/**
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* Returns the total amount of tokens minted in the contract.
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*/
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function _totalMinted() internal view returns (uint256) {
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// Counter underflow is impossible as _currentIndex does not decrement,
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// and it is initialized to _startTokenId()
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unchecked {
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return _currentIndex - _startTokenId();
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}
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}
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/**
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* @dev See {IERC165-supportsInterface}.
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*/
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function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
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return
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interfaceId == type(IERC721).interfaceId ||
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interfaceId == type(IERC721Metadata).interfaceId ||
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super.supportsInterface(interfaceId);
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}
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/**
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* @dev See {IERC721-balanceOf}.
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*/
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function balanceOf(address owner) public view override returns (uint256) {
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if (owner == address(0)) revert BalanceQueryForZeroAddress();
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return uint256(_addressData[owner].balance);
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}
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/**
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* Returns the number of tokens minted by `owner`.
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*/
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function _numberMinted(address owner) internal view returns (uint256) {
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if (owner == address(0)) revert MintedQueryForZeroAddress();
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return uint256(_addressData[owner].numberMinted);
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}
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/**
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* Returns the number of tokens burned by or on behalf of `owner`.
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*/
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function _numberBurned(address owner) internal view returns (uint256) {
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if (owner == address(0)) revert BurnedQueryForZeroAddress();
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return uint256(_addressData[owner].numberBurned);
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}
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/**
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* Returns the auxiliary data for `owner`. (e.g. number of whitelist mint slots used).
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*/
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function _getAux(address owner) internal view returns (uint64) {
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if (owner == address(0)) revert AuxQueryForZeroAddress();
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return _addressData[owner].aux;
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}
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/**
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* Sets the auxiliary data for `owner`. (e.g. number of whitelist mint slots used).
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* If there are multiple variables, please pack them into a uint64.
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*/
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function _setAux(address owner, uint64 aux) internal {
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if (owner == address(0)) revert AuxQueryForZeroAddress();
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_addressData[owner].aux = aux;
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}
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/**
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* Gas spent here starts off proportional to the maximum mint batch size.
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* It gradually moves to O(1) as tokens get transferred around in the collection over time.
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*/
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function ownershipOf(uint256 tokenId) internal view returns (TokenOwnership memory) {
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uint256 curr = tokenId;
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unchecked {
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if (_startTokenId() <= curr && curr < _currentIndex) {
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TokenOwnership memory ownership = _ownerships[curr];
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if (!ownership.burned) {
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if (ownership.addr != address(0)) {
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return ownership;
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}
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// Invariant:
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// There will always be an ownership that has an address and is not burned
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// before an ownership that does not have an address and is not burned.
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// Hence, curr will not underflow.
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while (true) {
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curr--;
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ownership = _ownerships[curr];
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if (ownership.addr != address(0)) {
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return ownership;
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}
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}
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}
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}
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}
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revert OwnerQueryForNonexistentToken();
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}
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/**
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* @dev See {IERC721-ownerOf}.
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*/
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function ownerOf(uint256 tokenId) public view override returns (address) {
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return ownershipOf(tokenId).addr;
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}
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/**
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* @dev See {IERC721Metadata-name}.
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*/
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function name() public view virtual override returns (string memory) {
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return _name;
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}
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/**
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* @dev See {IERC721Metadata-symbol}.
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*/
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function symbol() public view virtual override returns (string memory) {
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return _symbol;
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}
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/**
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* @dev See {IERC721Metadata-tokenURI}.
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*/
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function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
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if (!_exists(tokenId)) revert URIQueryForNonexistentToken();
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string memory baseURI = _baseURI();
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return bytes(baseURI).length != 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : '';
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}
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/**
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* @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
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* token will be the concatenation of the `baseURI` and the `tokenId`. Empty
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* by default, can be overridden in child contracts.
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*/
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function _baseURI() internal view virtual returns (string memory) {
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return '';
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}
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/**
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* @dev See {IERC721-approve}.
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*/
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function approve(address to, uint256 tokenId) public override {
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address owner = ERC721A.ownerOf(tokenId);
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if (to == owner) revert ApprovalToCurrentOwner();
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if (_msgSender() != owner && !isApprovedForAll(owner, _msgSender())) {
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revert ApprovalCallerNotOwnerNorApproved();
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}
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_approve(to, tokenId, owner);
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}
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/**
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* @dev See {IERC721-getApproved}.
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*/
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function getApproved(uint256 tokenId) public view override returns (address) {
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if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();
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return _tokenApprovals[tokenId];
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}
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/**
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* @dev See {IERC721-setApprovalForAll}.
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*/
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function setApprovalForAll(address operator, bool approved) public override {
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if (operator == _msgSender()) revert ApproveToCaller();
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_operatorApprovals[_msgSender()][operator] = approved;
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emit ApprovalForAll(_msgSender(), operator, approved);
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}
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/**
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* @dev See {IERC721-isApprovedForAll}.
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*/
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function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
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return _operatorApprovals[owner][operator];
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}
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/**
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* @dev See {IERC721-transferFrom}.
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*/
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function transferFrom(
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address from,
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address to,
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uint256 tokenId
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) public virtual override {
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_transfer(from, to, tokenId);
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}
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/**
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* @dev See {IERC721-safeTransferFrom}.
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*/
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function safeTransferFrom(
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address from,
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address to,
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uint256 tokenId
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) public virtual override {
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safeTransferFrom(from, to, tokenId, '');
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}
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/**
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* @dev See {IERC721-safeTransferFrom}.
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*/
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function safeTransferFrom(
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address from,
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address to,
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uint256 tokenId,
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bytes memory _data
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) public virtual override {
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_transfer(from, to, tokenId);
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if (to.isContract() && !_checkContractOnERC721Received(from, to, tokenId, _data)) {
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revert TransferToNonERC721ReceiverImplementer();
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}
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}
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/**
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* @dev Returns whether `tokenId` exists.
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*
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* Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
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*
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* Tokens start existing when they are minted (`_mint`),
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*/
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function _exists(uint256 tokenId) internal view returns (bool) {
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return _startTokenId() <= tokenId && tokenId < _currentIndex &&
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!_ownerships[tokenId].burned;
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}
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function _safeMint(address to, uint256 quantity) internal {
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_safeMint(to, quantity, '');
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}
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/**
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* @dev Safely mints `quantity` tokens and transfers them to `to`.
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*
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* Requirements:
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*
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* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called for each safe transfer.
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* - `quantity` must be greater than 0.
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*
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* Emits a {Transfer} event.
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*/
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function _safeMint(
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address to,
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uint256 quantity,
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bytes memory _data
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) internal {
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_mint(to, quantity, _data, true);
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}
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/**
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* @dev Mints `quantity` tokens and transfers them to `to`.
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*
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* Requirements:
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*
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* - `to` cannot be the zero address.
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* - `quantity` must be greater than 0.
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*
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* Emits a {Transfer} event.
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*/
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function _mint(
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address to,
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uint256 quantity,
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bytes memory _data,
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bool safe
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) internal {
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uint256 startTokenId = _currentIndex;
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if (to == address(0)) revert MintToZeroAddress();
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if (quantity == 0) revert MintZeroQuantity();
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_beforeTokenTransfers(address(0), to, startTokenId, quantity);
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// Overflows are incredibly unrealistic.
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// balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1
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// updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1
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unchecked {
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_addressData[to].balance += uint64(quantity);
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_addressData[to].numberMinted += uint64(quantity);
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_ownerships[startTokenId].addr = to;
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_ownerships[startTokenId].startTimestamp = uint64(block.timestamp);
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uint256 updatedIndex = startTokenId;
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uint256 end = updatedIndex + quantity;
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if (safe && to.isContract()) {
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do {
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emit Transfer(address(0), to, updatedIndex);
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if (!_checkContractOnERC721Received(address(0), to, updatedIndex++, _data)) {
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revert TransferToNonERC721ReceiverImplementer();
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}
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} while (updatedIndex != end);
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// Reentrancy protection
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if (_currentIndex != startTokenId) revert();
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} else {
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do {
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emit Transfer(address(0), to, updatedIndex++);
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} while (updatedIndex != end);
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}
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_currentIndex = updatedIndex;
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}
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_afterTokenTransfers(address(0), to, startTokenId, quantity);
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}
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/**
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* @dev Transfers `tokenId` from `from` to `to`.
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*
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* Requirements:
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*
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* - `to` cannot be the zero address.
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* - `tokenId` token must be owned by `from`.
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*
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* Emits a {Transfer} event.
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*/
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function _transfer(
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address from,
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address to,
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uint256 tokenId
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) private {
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TokenOwnership memory prevOwnership = ownershipOf(tokenId);
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bool isApprovedOrOwner = (_msgSender() == prevOwnership.addr ||
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isApprovedForAll(prevOwnership.addr, _msgSender()) ||
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getApproved(tokenId) == _msgSender());
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if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
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if (prevOwnership.addr != from) revert TransferFromIncorrectOwner();
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if (to == address(0)) revert TransferToZeroAddress();
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_beforeTokenTransfers(from, to, tokenId, 1);
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// Clear approvals from the previous owner
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_approve(address(0), tokenId, prevOwnership.addr);
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// Underflow of the sender's balance is impossible because we check for
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// ownership above and the recipient's balance can't realistically overflow.
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// Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.
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unchecked {
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_addressData[from].balance -= 1;
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_addressData[to].balance += 1;
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_ownerships[tokenId].addr = to;
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_ownerships[tokenId].startTimestamp = uint64(block.timestamp);
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// If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.
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// Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
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uint256 nextTokenId = tokenId + 1;
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if (_ownerships[nextTokenId].addr == address(0)) {
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// This will suffice for checking _exists(nextTokenId),
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// as a burned slot cannot contain the zero address.
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if (nextTokenId < _currentIndex) {
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_ownerships[nextTokenId].addr = prevOwnership.addr;
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_ownerships[nextTokenId].startTimestamp = prevOwnership.startTimestamp;
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}
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}
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}
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emit Transfer(from, to, tokenId);
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_afterTokenTransfers(from, to, tokenId, 1);
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}
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/**
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* @dev Destroys `tokenId`.
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* The approval is cleared when the token is burned.
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*
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* Requirements:
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*
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* - `tokenId` must exist.
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*
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* Emits a {Transfer} event.
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*/
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function _burn(uint256 tokenId) internal virtual {
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TokenOwnership memory prevOwnership = ownershipOf(tokenId);
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_beforeTokenTransfers(prevOwnership.addr, address(0), tokenId, 1);
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// Clear approvals from the previous owner
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_approve(address(0), tokenId, prevOwnership.addr);
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// Underflow of the sender's balance is impossible because we check for
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// ownership above and the recipient's balance can't realistically overflow.
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// Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.
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unchecked {
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_addressData[prevOwnership.addr].balance -= 1;
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_addressData[prevOwnership.addr].numberBurned += 1;
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// Keep track of who burned the token, and the timestamp of burning.
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_ownerships[tokenId].addr = prevOwnership.addr;
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_ownerships[tokenId].startTimestamp = uint64(block.timestamp);
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_ownerships[tokenId].burned = true;
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// If the ownership slot of tokenId+1 is not explicitly set, that means the burn initiator owns it.
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// Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
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uint256 nextTokenId = tokenId + 1;
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if (_ownerships[nextTokenId].addr == address(0)) {
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// This will suffice for checking _exists(nextTokenId),
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// as a burned slot cannot contain the zero address.
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if (nextTokenId < _currentIndex) {
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_ownerships[nextTokenId].addr = prevOwnership.addr;
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_ownerships[nextTokenId].startTimestamp = prevOwnership.startTimestamp;
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}
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}
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}
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emit Transfer(prevOwnership.addr, address(0), tokenId);
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_afterTokenTransfers(prevOwnership.addr, address(0), tokenId, 1);
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// Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.
|
|
unchecked {
|
|
_burnCounter++;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @dev Approve `to` to operate on `tokenId`
|
|
*
|
|
* Emits a {Approval} event.
|
|
*/
|
|
function _approve(
|
|
address to,
|
|
uint256 tokenId,
|
|
address owner
|
|
) private {
|
|
_tokenApprovals[tokenId] = to;
|
|
emit Approval(owner, to, tokenId);
|
|
}
|
|
|
|
/**
|
|
* @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target 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 _checkContractOnERC721Received(
|
|
address from,
|
|
address to,
|
|
uint256 tokenId,
|
|
bytes memory _data
|
|
) private returns (bool) {
|
|
try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
|
|
return retval == IERC721Receiver(to).onERC721Received.selector;
|
|
} catch (bytes memory reason) {
|
|
if (reason.length == 0) {
|
|
revert TransferToNonERC721ReceiverImplementer();
|
|
} else {
|
|
assembly {
|
|
revert(add(32, reason), mload(reason))
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @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 {}
|
|
} |