Transaction Hash:
Block:
14977548 at Jun-17-2022 05:45:54 AM +UTC
Transaction Fee:
0.000818760183071818 ETH
$1.97
Gas Used:
46,126 Gas / 17.750513443 Gwei
Emitted Events:
229 |
LastEssence.ApprovalForAll( owner=[Sender] 0x1e613416513a0cbbcf2c930e1488ffc9fa73ca2f, operator=0x1E004978...d54003c71, approved=True )
|
Account State Difference:
Address | Before | After | State Difference | ||
---|---|---|---|---|---|
0x1e613416...9Fa73CA2F |
2.090952725609359944 Eth
Nonce: 807
|
2.090133965426288126 Eth
Nonce: 808
| 0.000818760183071818 | ||
0x2B934DB3...5df8f8b05 | |||||
0x7F101fE4...353f2B90c
Miner
| (Flexpool.io) | 6,323.7130596398586309 Eth | 6,323.7131749548586309 Eth | 0.000115315 |
Execution Trace
LastEssence.setApprovalForAll( operator=0x1E0049783F008A0085193E00003D00cd54003c71, approved=True )
setApprovalForAll[ERC721A (ln:436)]
_msgSender[ERC721A (ln:440)]
_msgSender[ERC721A (ln:441)]
ApprovalForAll[ERC721A (ln:442)]
_msgSender[ERC721A (ln:442)]
// SPDX-License-Identifier: MIT pragma solidity >=0.8.13; import {ERC721A} from "ERC721A.sol"; import {Ownable} from "Ownable.sol"; import {ReentrancyGuard} from "ReentrancyGuard.sol"; import {Strings} from "Strings.sol"; import {PaymentSplitter} from "PaymentSplitter.sol"; import {MerkleProof} from "MerkleProof.sol"; error SaleNotStarted(); error NotOnReservedList(); error AlreadyClaimed(); error QuantityOffLimits(); error MaxSupplyReached(); error InsufficientFunds(); error NonExistentTokenURI(); contract LastEssence is Ownable, ERC721A, ReentrancyGuard, PaymentSplitter { using Strings for uint256; uint256 public immutable maxSupply = 3444; uint256 public immutable reserveSupply = 2254; uint256 public maxTokensPerTx = 5; uint256 public price = 0.022 ether; uint256 public reserveSaleStart = 1654444800; uint256 public reserveSaleEnd = reserveSaleStart + 7 hours; uint256 public claimed; bool public revealed; bytes32 public merkleRoot; string private _baseTokenURI; string private notRevealedUri; mapping(address => bool) private reserveClaimed; constructor( string memory name_, string memory symbol_, string memory _initNotRevealedUri, uint256 maxBatchSize_, address[] memory payees_, uint256[] memory shares_ ) ERC721A(name_, symbol_, maxBatchSize_) PaymentSplitter(payees_, shares_) { reserveForTeam(); setNotRevealedURI(_initNotRevealedUri); } function reserveSaleMint(uint256 quantity, bytes32[] memory proof) external payable { // Validation if ( block.timestamp < reserveSaleStart || block.timestamp > reserveSaleEnd ) revert SaleNotStarted(); if ( !( MerkleProof.verify( proof, merkleRoot, keccak256(abi.encodePacked(msg.sender)) ) ) ) revert NotOnReservedList(); if (totalSupply() + quantity > maxSupply || claimed + 1 > reserveSupply) revert MaxSupplyReached(); if (quantity == 0 || quantity > maxTokensPerTx) revert QuantityOffLimits(); if (reserveClaimed[msg.sender]) revert AlreadyClaimed(); // State changes reserveClaimed[msg.sender] = true; claimed++; // Interactions // if public supply is minted, only one per address can be minted if (totalSupply() + quantity > maxSupply - reserveSupply + claimed) { if (msg.value < price) revert InsufficientFunds(); _safeMint(msg.sender, 1); // if msg.value is for larger quantity, send the rest back if (msg.value > price) { payable(msg.sender).transfer(msg.value - price); } } else { if (msg.value != price * quantity) revert InsufficientFunds(); _safeMint(msg.sender, quantity); } } function publicSaleMint(uint256 quantity) external payable { // Validation if (block.timestamp < reserveSaleStart) revert SaleNotStarted(); if (msg.value != price * quantity) revert InsufficientFunds(); if (quantity == 0 || quantity > maxTokensPerTx) revert QuantityOffLimits(); // check if reserve sale period is over if (block.timestamp > reserveSaleEnd) { // reserve sale ended so all available for public if (totalSupply() + quantity > maxSupply) revert MaxSupplyReached(); } else { // reserve sale open so limited supply for public if (totalSupply() + quantity > maxSupply - reserveSupply + claimed) revert MaxSupplyReached(); } // Interactions _safeMint(msg.sender, quantity); } function isSaleOpen() public view returns (bool) { if (block.timestamp < reserveSaleStart) { return false; } return true; } function isReserveSaleOver() public view returns (bool) { if (block.timestamp < reserveSaleEnd) { return false; } return true; } function isAlreadyClaimed(address user) public view returns (bool) { if (reserveClaimed[user]) { return true; } return false; } function airdrop(address _to, uint256 quantity) external onlyOwner { if (totalSupply() + quantity > maxSupply) revert MaxSupplyReached(); _safeMint(_to, quantity); } function setReserveSaleStart(uint256 _timestamp) external onlyOwner { reserveSaleStart = _timestamp; } function setReserveSaleEnd(uint256 _timestamp) external onlyOwner { reserveSaleEnd = _timestamp; } function setPrice(uint64 _price) external onlyOwner { price = _price; } function setMaxTokensPerTx(uint256 _maxTokensPerTx) external onlyOwner { maxTokensPerTx = _maxTokensPerTx; } function setMerkleRoot(bytes32 _merkleRoot) external onlyOwner { merkleRoot = _merkleRoot; } function _baseURI() internal view virtual override returns (string memory) { return _baseTokenURI; } function setBaseURI(string calldata baseURI) external onlyOwner { _baseTokenURI = baseURI; } function setNotRevealedURI(string memory _notRevealedURI) public onlyOwner { notRevealedUri = _notRevealedURI; } function reserveForTeam() internal { _safeMint(0x6Cef9181747B2139CE4410a123997146e247DeBe, 5); _safeMint(0x0010F22e270Ea56eAA66Ca9D801F516A0853aaA6, 5); _safeMint(0xe9F37DCa944c8Bb9b71A0ee28202CED03390136B, 5); _safeMint(0x83882460157B1a14EA50A7e47a992aF0BEAb9331, 5); _safeMint(0x97956FCcEF9AFFC8fFb0D2a6C35a3b8D108F048b, 5); _safeMint(0x044Ab09cFd9312695F390AE1689C4661454fB64B, 5); _safeMint(0xE576C0f771BC3B4E5eabCCb425Ae533D9e00E953, 5); _safeMint(0x2bDAC6F14d46bd7e4e12d4865e92183DA34c8a99, 5); _safeMint(0xe5E334D0BB07B54B8f308871B793222186d15BCa, 5); _safeMint(0xbd4886Ab438a530a9f51fbc07Cb78597Eaf79eCF, 5); _safeMint(0x020cA4Aa1A32814a80Bde4c0ED67e1495836d27f, 5); _safeMint(0xec7d9C4462Cc30B102dF9e8Dfb8dA85a28C993EA, 45); } function setOwnersExplicit(uint256 quantity) external onlyOwner nonReentrant { _setOwnersExplicit(quantity); } function numberMinted(address owner) public view returns (uint256) { return _numberMinted(owner); } function getOwnerOfToken(uint256 tokenId) external view returns (TokenOwnership memory) { return ownershipOf(tokenId); } function reveal() public onlyOwner { revealed = true; } function tokenURI(uint256 tokenId) public view virtual override returns (string memory) { if (!_exists(tokenId)) revert NonExistentTokenURI(); if (revealed == false) { return notRevealedUri; } string memory baseURI = _baseURI(); return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString(), ".json")) : ""; } } // SPDX-License-Identifier: MIT // Creator: Chiru Labs pragma solidity ^0.8.0; import "IERC721.sol"; import "IERC721Receiver.sol"; import "IERC721Metadata.sol"; import "IERC721Enumerable.sol"; import "Address.sol"; import "Context.sol"; import "Strings.sol"; import "ERC165.sol"; /** * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including * the Metadata and Enumerable extension. Built to optimize for lower gas during batch mints. * * Assumes serials are sequentially minted starting at 0 (e.g. 0, 1, 2, 3..). * * Does not support burning tokens to address(0). */ contract ERC721A is Context, ERC165, IERC721, IERC721Metadata, IERC721Enumerable { using Address for address; using Strings for uint256; struct TokenOwnership { address addr; uint64 startTimestamp; } struct AddressData { uint128 balance; uint128 numberMinted; } uint256 private currentIndex = 0; uint256 internal immutable maxBatchSize; // 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 ownershipOf implementation for details. mapping(uint256 => TokenOwnership) private _ownerships; // Mapping owner address to address data mapping(address => AddressData) private _addressData; // Mapping from token ID to approved address mapping(uint256 => address) private _tokenApprovals; // Mapping from owner to operator approvals mapping(address => mapping(address => bool)) private _operatorApprovals; /** * @dev * `maxBatchSize` refers to how much a minter can mint at a time. */ constructor( string memory name_, string memory symbol_, uint256 maxBatchSize_ ) { require(maxBatchSize_ > 0, "ERC721A: max batch size must be nonzero"); _name = name_; _symbol = symbol_; maxBatchSize = maxBatchSize_; } /** * @dev See {IERC721Enumerable-totalSupply}. */ function totalSupply() public view override returns (uint256) { return currentIndex; } /** * @dev See {IERC721Enumerable-tokenByIndex}. */ function tokenByIndex(uint256 index) public view override returns (uint256) { require(index < totalSupply(), "ERC721A: global index out of bounds"); return index; } /** * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}. * This read function is O(totalSupply). If calling from a separate contract, be sure to test gas first. * It may also degrade with extremely large collection sizes (e.g >> 10000), test for your use case. */ function tokenOfOwnerByIndex(address owner, uint256 index) public view override returns (uint256) { require(index < balanceOf(owner), "ERC721A: owner index out of bounds"); uint256 numMintedSoFar = totalSupply(); uint256 tokenIdsIdx = 0; address currOwnershipAddr = address(0); for (uint256 i = 0; i < numMintedSoFar; i++) { TokenOwnership memory ownership = _ownerships[i]; if (ownership.addr != address(0)) { currOwnershipAddr = ownership.addr; } if (currOwnershipAddr == owner) { if (tokenIdsIdx == index) { return i; } tokenIdsIdx++; } } revert("ERC721A: unable to get token of owner by index"); } /** * @dev See {IERC165-supportsInterface}. */ function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) { return interfaceId == type(IERC721).interfaceId || interfaceId == type(IERC721Metadata).interfaceId || interfaceId == type(IERC721Enumerable).interfaceId || super.supportsInterface(interfaceId); } /** * @dev See {IERC721-balanceOf}. */ function balanceOf(address owner) public view override returns (uint256) { require( owner != address(0), "ERC721A: balance query for the zero address" ); return uint256(_addressData[owner].balance); } function _numberMinted(address owner) internal view returns (uint256) { require( owner != address(0), "ERC721A: number minted query for the zero address" ); return uint256(_addressData[owner].numberMinted); } function ownershipOf(uint256 tokenId) internal view returns (TokenOwnership memory) { require(_exists(tokenId), "ERC721A: owner query for nonexistent token"); uint256 lowestTokenToCheck; if (tokenId >= maxBatchSize) { lowestTokenToCheck = tokenId - maxBatchSize + 1; } for (uint256 curr = tokenId; curr >= lowestTokenToCheck; curr--) { TokenOwnership memory ownership = _ownerships[curr]; if (ownership.addr != address(0)) { return ownership; } } revert("ERC721A: unable to determine the owner of token"); } /** * @dev See {IERC721-ownerOf}. */ function ownerOf(uint256 tokenId) public view override returns (address) { return ownershipOf(tokenId).addr; } /** * @dev See {IERC721Metadata-name}. */ function name() public view virtual override returns (string memory) { return _name; } /** * @dev See {IERC721Metadata-symbol}. */ function symbol() public view virtual override returns (string memory) { return _symbol; } /** * @dev See {IERC721Metadata-tokenURI}. */ function tokenURI(uint256 tokenId) public view virtual override returns (string memory) { require( _exists(tokenId), "ERC721Metadata: URI query for nonexistent token" ); string memory baseURI = _baseURI(); return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : ""; } /** * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each * token will be the concatenation of the `baseURI` and the `tokenId`. Empty * by default, can be overriden in child contracts. */ function _baseURI() internal view virtual returns (string memory) { return ""; } /** * @dev See {IERC721-approve}. */ function approve(address to, uint256 tokenId) public override { address owner = ERC721A.ownerOf(tokenId); require(to != owner, "ERC721A: approval to current owner"); require( _msgSender() == owner || isApprovedForAll(owner, _msgSender()), "ERC721A: approve caller is not owner nor approved for all" ); _approve(to, tokenId, owner); } /** * @dev See {IERC721-getApproved}. */ function getApproved(uint256 tokenId) public view override returns (address) { require( _exists(tokenId), "ERC721A: approved query for nonexistent token" ); return _tokenApprovals[tokenId]; } /** * @dev See {IERC721-setApprovalForAll}. */ function setApprovalForAll(address operator, bool approved) public override { require(operator != _msgSender(), "ERC721A: approve to caller"); _operatorApprovals[_msgSender()][operator] = approved; emit ApprovalForAll(_msgSender(), operator, approved); } /** * @dev See {IERC721-isApprovedForAll}. */ function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) { return _operatorApprovals[owner][operator]; } /** * @dev See {IERC721-transferFrom}. */ function transferFrom( address from, address to, uint256 tokenId ) public override { _transfer(from, to, tokenId); } /** * @dev See {IERC721-safeTransferFrom}. */ function safeTransferFrom( address from, address to, uint256 tokenId ) public override { safeTransferFrom(from, to, tokenId, ""); } /** * @dev See {IERC721-safeTransferFrom}. */ function safeTransferFrom( address from, address to, uint256 tokenId, bytes memory _data ) public override { _transfer(from, to, tokenId); require( _checkOnERC721Received(from, to, tokenId, _data), "ERC721A: transfer to non ERC721Receiver implementer" ); } /** * @dev Returns whether `tokenId` exists. * * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}. * * Tokens start existing when they are minted (`_mint`), */ function _exists(uint256 tokenId) internal view returns (bool) { return tokenId < currentIndex; } function _safeMint(address to, uint256 quantity) internal { _safeMint(to, quantity, ""); } /** * @dev Mints `quantity` tokens and transfers them to `to`. * * Requirements: * * - `to` cannot be the zero address. * - `quantity` cannot be larger than the max batch size. * * Emits a {Transfer} event. */ function _safeMint( address to, uint256 quantity, bytes memory _data ) internal { uint256 startTokenId = currentIndex; require(to != address(0), "ERC721A: mint to the zero address"); // We know if the first token in the batch doesn't exist, the other ones don't as well, because of serial ordering. require(!_exists(startTokenId), "ERC721A: token already minted"); require(quantity <= maxBatchSize, "ERC721A: quantity to mint too high"); _beforeTokenTransfers(address(0), to, startTokenId, quantity); AddressData memory addressData = _addressData[to]; _addressData[to] = AddressData( addressData.balance + uint128(quantity), addressData.numberMinted + uint128(quantity) ); _ownerships[startTokenId] = TokenOwnership(to, uint64(block.timestamp)); uint256 updatedIndex = startTokenId; for (uint256 i = 0; i < quantity; i++) { emit Transfer(address(0), to, updatedIndex); require( _checkOnERC721Received(address(0), to, updatedIndex, _data), "ERC721A: transfer to non ERC721Receiver implementer" ); updatedIndex++; } currentIndex = updatedIndex; _afterTokenTransfers(address(0), to, startTokenId, quantity); } /** * @dev Transfers `tokenId` from `from` to `to`. * * Requirements: * * - `to` cannot be the zero address. * - `tokenId` token must be owned by `from`. * * Emits a {Transfer} event. */ function _transfer( address from, address to, uint256 tokenId ) private { TokenOwnership memory prevOwnership = ownershipOf(tokenId); bool isApprovedOrOwner = (_msgSender() == prevOwnership.addr || getApproved(tokenId) == _msgSender() || isApprovedForAll(prevOwnership.addr, _msgSender())); require( isApprovedOrOwner, "ERC721A: transfer caller is not owner nor approved" ); require( prevOwnership.addr == from, "ERC721A: transfer from incorrect owner" ); require(to != address(0), "ERC721A: transfer to the zero address"); _beforeTokenTransfers(from, to, tokenId, 1); // Clear approvals from the previous owner _approve(address(0), tokenId, prevOwnership.addr); _addressData[from].balance -= 1; _addressData[to].balance += 1; _ownerships[tokenId] = TokenOwnership(to, uint64(block.timestamp)); // If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it. // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls. uint256 nextTokenId = tokenId + 1; if (_ownerships[nextTokenId].addr == address(0)) { if (_exists(nextTokenId)) { _ownerships[nextTokenId] = TokenOwnership( prevOwnership.addr, prevOwnership.startTimestamp ); } } emit Transfer(from, to, tokenId); _afterTokenTransfers(from, to, tokenId, 1); } /** * @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); } uint256 public nextOwnerToExplicitlySet = 0; /** * @dev Explicitly set `owners` to eliminate loops in future calls of ownerOf(). */ function _setOwnersExplicit(uint256 quantity) internal { uint256 oldNextOwnerToSet = nextOwnerToExplicitlySet; require(quantity > 0, "quantity must be nonzero"); uint256 endIndex = oldNextOwnerToSet + quantity - 1; if (endIndex > currentIndex - 1) { endIndex = currentIndex - 1; } // We know if the last one in the group exists, all in the group exist, due to serial ordering. require(_exists(endIndex), "not enough minted yet for this cleanup"); for (uint256 i = oldNextOwnerToSet; i <= endIndex; i++) { if (_ownerships[i].addr == address(0)) { TokenOwnership memory ownership = ownershipOf(i); _ownerships[i] = TokenOwnership( ownership.addr, ownership.startTimestamp ); } } nextOwnerToExplicitlySet = endIndex + 1; } /** * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address. * The call is not executed if the target address is not a contract. * * @param from address representing the previous owner of the given token ID * @param to target address that will receive the tokens * @param tokenId uint256 ID of the token to be transferred * @param _data bytes optional data to send along with the call * @return bool whether the call correctly returned the expected magic value */ function _checkOnERC721Received( address from, address to, uint256 tokenId, bytes memory _data ) private returns (bool) { if (to.isContract()) { try IERC721Receiver(to).onERC721Received( _msgSender(), from, tokenId, _data ) returns (bytes4 retval) { return retval == IERC721Receiver(to).onERC721Received.selector; } catch (bytes memory reason) { if (reason.length == 0) { revert( "ERC721A: transfer to non ERC721Receiver implementer" ); } else { assembly { revert(add(32, reason), mload(reason)) } } } } else { return true; } } /** * @dev Hook that is called before a set of serially-ordered token ids are about to be transferred. This includes minting. * * 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`. */ 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. * * 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` and `to` are never both zero. */ function _afterTokenTransfers( address from, address to, uint256 startTokenId, uint256 quantity ) internal virtual {} } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol) pragma solidity ^0.8.0; import "IERC165.sol"; /** * @dev Required interface of an ERC721 compliant contract. */ interface IERC721 is IERC165 { /** * @dev Emitted when `tokenId` token is transferred from `from` to `to`. */ event Transfer(address indexed from, address indexed to, uint256 indexed tokenId); /** * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token. */ event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId); /** * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets. */ event ApprovalForAll(address indexed owner, address indexed operator, bool approved); /** * @dev Returns the number of tokens in ``owner``'s account. */ function balanceOf(address owner) external view returns (uint256 balance); /** * @dev Returns the owner of the `tokenId` token. * * Requirements: * * - `tokenId` must exist. */ function ownerOf(uint256 tokenId) external view returns (address owner); /** * @dev Safely transfers `tokenId` token from `from` to `to`, 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 ) external; /** * @dev Transfers `tokenId` token 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; /** * @dev Gives permission to `to` to transfer `tokenId` token to another account. * The approval is cleared when the token is transferred. * * Only a single account can be approved at a time, so approving the zero address clears previous approvals. * * Requirements: * * - The caller must own the token or be an approved operator. * - `tokenId` must exist. * * Emits an {Approval} event. */ function approve(address to, uint256 tokenId) external; /** * @dev Returns the account approved for `tokenId` token. * * Requirements: * * - `tokenId` must exist. */ function getApproved(uint256 tokenId) external view returns (address operator); /** * @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 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); /** * @dev Safely transfers `tokenId` token from `from` to `to`. * * Requirements: * * - `from` cannot be the zero address. * - `to` cannot be the zero address. * - `tokenId` token must exist and be owned by `from`. * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}. * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer. * * Emits a {Transfer} event. */ function safeTransferFrom( address from, address to, uint256 tokenId, bytes calldata data ) external; } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol) pragma solidity ^0.8.0; /** * @dev Interface of the ERC165 standard, as defined in the * https://eips.ethereum.org/EIPS/eip-165[EIP]. * * Implementers can declare support of contract interfaces, which can then be * queried by others ({ERC165Checker}). * * For an implementation, see {ERC165}. */ interface IERC165 { /** * @dev Returns true if this contract implements the interface defined by * `interfaceId`. See the corresponding * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section] * to learn more about how these ids are created. * * This function call must use less than 30 000 gas. */ function supportsInterface(bytes4 interfaceId) external view returns (bool); } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721Receiver.sol) pragma solidity ^0.8.0; /** * @title ERC721 token receiver interface * @dev Interface for any contract that wants to support safeTransfers * from ERC721 asset contracts. */ interface IERC721Receiver { /** * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom} * by `operator` from `from`, this function is called. * * It must return its Solidity selector to confirm the token transfer. * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted. * * The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`. */ function onERC721Received( address operator, address from, uint256 tokenId, bytes calldata data ) external returns (bytes4); } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol) pragma solidity ^0.8.0; import "IERC721.sol"; /** * @title ERC-721 Non-Fungible Token Standard, optional metadata extension * @dev See https://eips.ethereum.org/EIPS/eip-721 */ interface IERC721Metadata is IERC721 { /** * @dev Returns the token collection name. */ function name() external view returns (string memory); /** * @dev Returns the token collection symbol. */ function symbol() external view returns (string memory); /** * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token. */ function tokenURI(uint256 tokenId) external view returns (string memory); } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/extensions/IERC721Enumerable.sol) pragma solidity ^0.8.0; import "IERC721.sol"; /** * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension * @dev See https://eips.ethereum.org/EIPS/eip-721 */ interface IERC721Enumerable is IERC721 { /** * @dev Returns the total amount of tokens stored by the contract. */ function totalSupply() external view returns (uint256); /** * @dev Returns a token ID owned by `owner` at a given `index` of its token list. * Use along with {balanceOf} to enumerate all of ``owner``'s tokens. */ function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256); /** * @dev Returns a token ID at a given `index` of all the tokens stored by the contract. * Use along with {totalSupply} to enumerate all tokens. */ function tokenByIndex(uint256 index) external view returns (uint256); } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol) pragma solidity ^0.8.1; /** * @dev Collection of functions related to the address type */ library Address { /** * @dev Returns true if `account` is a contract. * * [IMPORTANT] * ==== * It is unsafe to assume that an address for which this function returns * false is an externally-owned account (EOA) and not a contract. * * Among others, `isContract` will return false for the following * types of addresses: * * - an externally-owned account * - a contract in construction * - an address where a contract will be created * - an address where a contract lived, but was destroyed * ==== * * [IMPORTANT] * ==== * You shouldn't rely on `isContract` to protect against flash loan attacks! * * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract * constructor. * ==== */ function isContract(address account) internal view returns (bool) { // This method relies on extcodesize/address.code.length, which returns 0 // for contracts in construction, since the code is only stored at the end // of the constructor execution. return account.code.length > 0; } /** * @dev Replacement for Solidity's `transfer`: sends `amount` wei to * `recipient`, forwarding all available gas and reverting on errors. * * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost * of certain opcodes, possibly making contracts go over the 2300 gas limit * imposed by `transfer`, making them unable to receive funds via * `transfer`. {sendValue} removes this limitation. * * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more]. * * IMPORTANT: because control is transferred to `recipient`, care must be * taken to not create reentrancy vulnerabilities. Consider using * {ReentrancyGuard} or the * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern]. */ function sendValue(address payable recipient, uint256 amount) internal { require(address(this).balance >= amount, "Address: insufficient balance"); (bool success, ) = recipient.call{value: amount}(""); require(success, "Address: unable to send value, recipient may have reverted"); } /** * @dev Performs a Solidity function call using a low level `call`. A * plain `call` is an unsafe replacement for a function call: use this * function instead. * * If `target` reverts with a revert reason, it is bubbled up by this * function (like regular Solidity function calls). * * Returns the raw returned data. To convert to the expected return value, * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`]. * * Requirements: * * - `target` must be a contract. * - calling `target` with `data` must not revert. * * _Available since v3.1._ */ function functionCall(address target, bytes memory data) internal returns (bytes memory) { return functionCall(target, data, "Address: low-level call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with * `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCall( address target, bytes memory data, string memory errorMessage ) internal returns (bytes memory) { return functionCallWithValue(target, data, 0, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but also transferring `value` wei to `target`. * * Requirements: * * - the calling contract must have an ETH balance of at least `value`. * - the called Solidity function must be `payable`. * * _Available since v3.1._ */ function functionCallWithValue( address target, bytes memory data, uint256 value ) internal returns (bytes memory) { return functionCallWithValue(target, data, value, "Address: low-level call with value failed"); } /** * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but * with `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCallWithValue( address target, bytes memory data, uint256 value, string memory errorMessage ) internal returns (bytes memory) { require(address(this).balance >= value, "Address: insufficient balance for call"); require(isContract(target), "Address: call to non-contract"); (bool success, bytes memory returndata) = target.call{value: value}(data); return verifyCallResult(success, returndata, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but performing a static call. * * _Available since v3.3._ */ function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) { return functionStaticCall(target, data, "Address: low-level static call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`], * but performing a static call. * * _Available since v3.3._ */ function functionStaticCall( address target, bytes memory data, string memory errorMessage ) internal view returns (bytes memory) { require(isContract(target), "Address: static call to non-contract"); (bool success, bytes memory returndata) = target.staticcall(data); return verifyCallResult(success, returndata, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but performing a delegate call. * * _Available since v3.4._ */ function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) { return functionDelegateCall(target, data, "Address: low-level delegate call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`], * but performing a delegate call. * * _Available since v3.4._ */ function functionDelegateCall( address target, bytes memory data, string memory errorMessage ) internal returns (bytes memory) { require(isContract(target), "Address: delegate call to non-contract"); (bool success, bytes memory returndata) = target.delegatecall(data); return verifyCallResult(success, returndata, errorMessage); } /** * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the * revert reason using the provided one. * * _Available since v4.3._ */ function verifyCallResult( bool success, bytes memory returndata, string memory errorMessage ) internal pure returns (bytes memory) { if (success) { return returndata; } else { // Look for revert reason and bubble it up if present if (returndata.length > 0) { // The easiest way to bubble the revert reason is using memory via assembly assembly { let returndata_size := mload(returndata) revert(add(32, returndata), returndata_size) } } else { revert(errorMessage); } } } } // 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 // OpenZeppelin Contracts v4.4.1 (utils/Strings.sol) pragma solidity ^0.8.0; /** * @dev String operations. */ library Strings { bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef"; /** * @dev Converts a `uint256` to its ASCII `string` decimal representation. */ function toString(uint256 value) internal pure returns (string memory) { // Inspired by OraclizeAPI's implementation - MIT licence // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol if (value == 0) { return "0"; } uint256 temp = value; uint256 digits; while (temp != 0) { digits++; temp /= 10; } bytes memory buffer = new bytes(digits); while (value != 0) { digits -= 1; buffer[digits] = bytes1(uint8(48 + uint256(value % 10))); value /= 10; } return string(buffer); } /** * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation. */ function toHexString(uint256 value) internal pure returns (string memory) { if (value == 0) { return "0x00"; } uint256 temp = value; uint256 length = 0; while (temp != 0) { length++; temp >>= 8; } return toHexString(value, length); } /** * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length. */ function toHexString(uint256 value, uint256 length) internal pure returns (string memory) { bytes memory buffer = new bytes(2 * length + 2); buffer[0] = "0"; buffer[1] = "x"; for (uint256 i = 2 * length + 1; i > 1; --i) { buffer[i] = _HEX_SYMBOLS[value & 0xf]; value >>= 4; } require(value == 0, "Strings: hex length insufficient"); return string(buffer); } } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol) pragma solidity ^0.8.0; import "IERC165.sol"; /** * @dev Implementation of the {IERC165} interface. * * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check * for the additional interface id that will be supported. For example: * * ```solidity * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) { * return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId); * } * ``` * * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation. */ abstract contract ERC165 is IERC165 { /** * @dev See {IERC165-supportsInterface}. */ function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) { return interfaceId == type(IERC165).interfaceId; } } // 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 // OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol) pragma solidity ^0.8.0; /** * @dev Contract module that helps prevent reentrant calls to a function. * * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier * available, which can be applied to functions to make sure there are no nested * (reentrant) calls to them. * * Note that because there is a single `nonReentrant` guard, functions marked as * `nonReentrant` may not call one another. This can be worked around by making * those functions `private`, and then adding `external` `nonReentrant` entry * points to them. * * TIP: If you would like to learn more about reentrancy and alternative ways * to protect against it, check out our blog post * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul]. */ abstract contract ReentrancyGuard { // Booleans are more expensive than uint256 or any type that takes up a full // word because each write operation emits an extra SLOAD to first read the // slot's contents, replace the bits taken up by the boolean, and then write // back. This is the compiler's defense against contract upgrades and // pointer aliasing, and it cannot be disabled. // The values being non-zero value makes deployment a bit more expensive, // but in exchange the refund on every call to nonReentrant will be lower in // amount. Since refunds are capped to a percentage of the total // transaction's gas, it is best to keep them low in cases like this one, to // increase the likelihood of the full refund coming into effect. uint256 private constant _NOT_ENTERED = 1; uint256 private constant _ENTERED = 2; uint256 private _status; constructor() { _status = _NOT_ENTERED; } /** * @dev Prevents a contract from calling itself, directly or indirectly. * Calling a `nonReentrant` function from another `nonReentrant` * function is not supported. It is possible to prevent this from happening * by making the `nonReentrant` function external, and making it call a * `private` function that does the actual work. */ modifier nonReentrant() { // On the first call to nonReentrant, _notEntered will be true require(_status != _ENTERED, "ReentrancyGuard: reentrant call"); // Any calls to nonReentrant after this point will fail _status = _ENTERED; _; // By storing the original value once again, a refund is triggered (see // https://eips.ethereum.org/EIPS/eip-2200) _status = _NOT_ENTERED; } } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (finance/PaymentSplitter.sol) pragma solidity ^0.8.0; import "SafeERC20.sol"; import "Address.sol"; import "Context.sol"; /** * @title PaymentSplitter * @dev This contract allows to split Ether payments among a group of accounts. The sender does not need to be aware * that the Ether will be split in this way, since it is handled transparently by the contract. * * The split can be in equal parts or in any other arbitrary proportion. The way this is specified is by assigning each * account to a number of shares. Of all the Ether that this contract receives, each account will then be able to claim * an amount proportional to the percentage of total shares they were assigned. * * `PaymentSplitter` follows a _pull payment_ model. This means that payments are not automatically forwarded to the * accounts but kept in this contract, and the actual transfer is triggered as a separate step by calling the {release} * function. * * NOTE: This contract assumes that ERC20 tokens will behave similarly to native tokens (Ether). Rebasing tokens, and * tokens that apply fees during transfers, are likely to not be supported as expected. If in doubt, we encourage you * to run tests before sending real value to this contract. */ contract PaymentSplitter is Context { event PayeeAdded(address account, uint256 shares); event PaymentReleased(address to, uint256 amount); event ERC20PaymentReleased(IERC20 indexed token, address to, uint256 amount); event PaymentReceived(address from, uint256 amount); uint256 private _totalShares; uint256 private _totalReleased; mapping(address => uint256) private _shares; mapping(address => uint256) private _released; address[] private _payees; mapping(IERC20 => uint256) private _erc20TotalReleased; mapping(IERC20 => mapping(address => uint256)) private _erc20Released; /** * @dev Creates an instance of `PaymentSplitter` where each account in `payees` is assigned the number of shares at * the matching position in the `shares` array. * * All addresses in `payees` must be non-zero. Both arrays must have the same non-zero length, and there must be no * duplicates in `payees`. */ constructor(address[] memory payees, uint256[] memory shares_) payable { require(payees.length == shares_.length, "PaymentSplitter: payees and shares length mismatch"); require(payees.length > 0, "PaymentSplitter: no payees"); for (uint256 i = 0; i < payees.length; i++) { _addPayee(payees[i], shares_[i]); } } /** * @dev The Ether received will be logged with {PaymentReceived} events. Note that these events are not fully * reliable: it's possible for a contract to receive Ether without triggering this function. This only affects the * reliability of the events, and not the actual splitting of Ether. * * To learn more about this see the Solidity documentation for * https://solidity.readthedocs.io/en/latest/contracts.html#fallback-function[fallback * functions]. */ receive() external payable virtual { emit PaymentReceived(_msgSender(), msg.value); } /** * @dev Getter for the total shares held by payees. */ function totalShares() public view returns (uint256) { return _totalShares; } /** * @dev Getter for the total amount of Ether already released. */ function totalReleased() public view returns (uint256) { return _totalReleased; } /** * @dev Getter for the total amount of `token` already released. `token` should be the address of an IERC20 * contract. */ function totalReleased(IERC20 token) public view returns (uint256) { return _erc20TotalReleased[token]; } /** * @dev Getter for the amount of shares held by an account. */ function shares(address account) public view returns (uint256) { return _shares[account]; } /** * @dev Getter for the amount of Ether already released to a payee. */ function released(address account) public view returns (uint256) { return _released[account]; } /** * @dev Getter for the amount of `token` tokens already released to a payee. `token` should be the address of an * IERC20 contract. */ function released(IERC20 token, address account) public view returns (uint256) { return _erc20Released[token][account]; } /** * @dev Getter for the address of the payee number `index`. */ function payee(uint256 index) public view returns (address) { return _payees[index]; } /** * @dev Triggers a transfer to `account` of the amount of Ether they are owed, according to their percentage of the * total shares and their previous withdrawals. */ function release(address payable account) public virtual { require(_shares[account] > 0, "PaymentSplitter: account has no shares"); uint256 totalReceived = address(this).balance + totalReleased(); uint256 payment = _pendingPayment(account, totalReceived, released(account)); require(payment != 0, "PaymentSplitter: account is not due payment"); _released[account] += payment; _totalReleased += payment; Address.sendValue(account, payment); emit PaymentReleased(account, payment); } /** * @dev Triggers a transfer to `account` of the amount of `token` tokens they are owed, according to their * percentage of the total shares and their previous withdrawals. `token` must be the address of an IERC20 * contract. */ function release(IERC20 token, address account) public virtual { require(_shares[account] > 0, "PaymentSplitter: account has no shares"); uint256 totalReceived = token.balanceOf(address(this)) + totalReleased(token); uint256 payment = _pendingPayment(account, totalReceived, released(token, account)); require(payment != 0, "PaymentSplitter: account is not due payment"); _erc20Released[token][account] += payment; _erc20TotalReleased[token] += payment; SafeERC20.safeTransfer(token, account, payment); emit ERC20PaymentReleased(token, account, payment); } /** * @dev internal logic for computing the pending payment of an `account` given the token historical balances and * already released amounts. */ function _pendingPayment( address account, uint256 totalReceived, uint256 alreadyReleased ) private view returns (uint256) { return (totalReceived * _shares[account]) / _totalShares - alreadyReleased; } /** * @dev Add a new payee to the contract. * @param account The address of the payee to add. * @param shares_ The number of shares owned by the payee. */ function _addPayee(address account, uint256 shares_) private { require(account != address(0), "PaymentSplitter: account is the zero address"); require(shares_ > 0, "PaymentSplitter: shares are 0"); require(_shares[account] == 0, "PaymentSplitter: account already has shares"); _payees.push(account); _shares[account] = shares_; _totalShares = _totalShares + shares_; emit PayeeAdded(account, shares_); } } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol) pragma solidity ^0.8.0; import "IERC20.sol"; import "Address.sol"; /** * @title SafeERC20 * @dev Wrappers around ERC20 operations that throw on failure (when the token * contract returns false). Tokens that return no value (and instead revert or * throw on failure) are also supported, non-reverting calls are assumed to be * successful. * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract, * which allows you to call the safe operations as `token.safeTransfer(...)`, etc. */ library SafeERC20 { using Address for address; function safeTransfer( IERC20 token, address to, uint256 value ) internal { _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value)); } function safeTransferFrom( IERC20 token, address from, address to, uint256 value ) internal { _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value)); } /** * @dev Deprecated. This function has issues similar to the ones found in * {IERC20-approve}, and its usage is discouraged. * * Whenever possible, use {safeIncreaseAllowance} and * {safeDecreaseAllowance} instead. */ function safeApprove( IERC20 token, address spender, uint256 value ) internal { // safeApprove should only be called when setting an initial allowance, // or when resetting it to zero. To increase and decrease it, use // 'safeIncreaseAllowance' and 'safeDecreaseAllowance' require( (value == 0) || (token.allowance(address(this), spender) == 0), "SafeERC20: approve from non-zero to non-zero allowance" ); _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value)); } function safeIncreaseAllowance( IERC20 token, address spender, uint256 value ) internal { uint256 newAllowance = token.allowance(address(this), spender) + value; _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance)); } function safeDecreaseAllowance( IERC20 token, address spender, uint256 value ) internal { unchecked { uint256 oldAllowance = token.allowance(address(this), spender); require(oldAllowance >= value, "SafeERC20: decreased allowance below zero"); uint256 newAllowance = oldAllowance - value; _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance)); } } /** * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement * on the return value: the return value is optional (but if data is returned, it must not be false). * @param token The token targeted by the call. * @param data The call data (encoded using abi.encode or one of its variants). */ function _callOptionalReturn(IERC20 token, bytes memory data) private { // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that // the target address contains contract code and also asserts for success in the low-level call. bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed"); if (returndata.length > 0) { // Return data is optional require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed"); } } } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/IERC20.sol) pragma solidity ^0.8.0; /** * @dev Interface of the ERC20 standard as defined in the EIP. */ interface IERC20 { /** * @dev Returns the amount of tokens in existence. */ function totalSupply() external view returns (uint256); /** * @dev Returns the amount of tokens owned by `account`. */ function balanceOf(address account) external view returns (uint256); /** * @dev Moves `amount` tokens from the caller's account to `to`. * * Returns a boolean value indicating whether the operation succeeded. * * Emits a {Transfer} event. */ function transfer(address to, uint256 amount) external returns (bool); /** * @dev Returns the remaining number of tokens that `spender` will be * allowed to spend on behalf of `owner` through {transferFrom}. This is * zero by default. * * This value changes when {approve} or {transferFrom} are called. */ function allowance(address owner, address spender) external view returns (uint256); /** * @dev Sets `amount` as the allowance of `spender` over the caller's tokens. * * Returns a boolean value indicating whether the operation succeeded. * * IMPORTANT: Beware that changing an allowance with this method brings the risk * that someone may use both the old and the new allowance by unfortunate * transaction ordering. One possible solution to mitigate this race * condition is to first reduce the spender's allowance to 0 and set the * desired value afterwards: * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729 * * Emits an {Approval} event. */ function approve(address spender, uint256 amount) external returns (bool); /** * @dev Moves `amount` tokens from `from` to `to` using the * allowance mechanism. `amount` is then deducted from the caller's * allowance. * * Returns a boolean value indicating whether the operation succeeded. * * Emits a {Transfer} event. */ function transferFrom( address from, address to, uint256 amount ) external returns (bool); /** * @dev Emitted when `value` tokens are moved from one account (`from`) to * another (`to`). * * Note that `value` may be zero. */ event Transfer(address indexed from, address indexed to, uint256 value); /** * @dev Emitted when the allowance of a `spender` for an `owner` is set by * a call to {approve}. `value` is the new allowance. */ event Approval(address indexed owner, address indexed spender, uint256 value); } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.5.0) (utils/cryptography/MerkleProof.sol) pragma solidity ^0.8.0; /** * @dev These functions deal with verification of Merkle Trees proofs. * * The proofs can be generated using the JavaScript library * https://github.com/miguelmota/merkletreejs[merkletreejs]. * Note: the hashing algorithm should be keccak256 and pair sorting should be enabled. * * See `test/utils/cryptography/MerkleProof.test.js` for some examples. */ library MerkleProof { /** * @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree * defined by `root`. For this, a `proof` must be provided, containing * sibling hashes on the branch from the leaf to the root of the tree. Each * pair of leaves and each pair of pre-images are assumed to be sorted. */ function verify( bytes32[] memory proof, bytes32 root, bytes32 leaf ) internal pure returns (bool) { return processProof(proof, leaf) == root; } /** * @dev Returns the rebuilt hash obtained by traversing a Merklee tree up * from `leaf` using `proof`. A `proof` is valid if and only if the rebuilt * hash matches the root of the tree. When processing the proof, the pairs * of leafs & pre-images are assumed to be sorted. * * _Available since v4.4._ */ function processProof(bytes32[] memory proof, bytes32 leaf) internal pure returns (bytes32) { bytes32 computedHash = leaf; for (uint256 i = 0; i < proof.length; i++) { bytes32 proofElement = proof[i]; if (computedHash <= proofElement) { // Hash(current computed hash + current element of the proof) computedHash = _efficientHash(computedHash, proofElement); } else { // Hash(current element of the proof + current computed hash) computedHash = _efficientHash(proofElement, computedHash); } } return computedHash; } function _efficientHash(bytes32 a, bytes32 b) private pure returns (bytes32 value) { assembly { mstore(0x00, a) mstore(0x20, b) value := keccak256(0x00, 0x40) } } }