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March 1, 2022 06:10
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| /** | |
| *Submitted for verification at Etherscan.io on 2020-08-27 | |
| */ | |
| pragma solidity ^0.5.0; | |
| contract BuilderShop { | |
| address[] builderInstances; | |
| uint contractId = 0; | |
| //nifty registry is hard coded | |
| address niftyRegistryContract = 0x6e53130dDfF21E3BC963Ee902005223b9A202106; | |
| modifier onlyValidSender() { | |
| NiftyRegistry nftg_registry = NiftyRegistry(niftyRegistryContract); | |
| bool is_valid = nftg_registry.isValidNiftySender(msg.sender); | |
| require(is_valid==true); | |
| _; | |
| } | |
| mapping (address => bool) public BuilderShops; | |
| function isValidBuilderShop(address builder_shop) public view returns (bool isValid) { | |
| //public function, allowing anyone to check if a contract address is a valid nifty gateway contract | |
| return(BuilderShops[builder_shop]); | |
| } | |
| event BuilderInstanceCreated(address new_contract_address, uint contractId); | |
| function createNewBuilderInstance( | |
| string memory _name, | |
| string memory _symbol, | |
| uint num_nifties, | |
| string memory token_base_uri, | |
| string memory creator_name) | |
| public returns (NiftyBuilderInstance tokenAddress) { // <- must replace this !!! | |
| //public onlyValidSender returns (NiftyBuilderInstance tokenAddress) { | |
| contractId = contractId + 1; | |
| NiftyBuilderInstance new_contract = new NiftyBuilderInstance( | |
| _name, | |
| _symbol, | |
| contractId, | |
| num_nifties, | |
| token_base_uri, | |
| creator_name | |
| ); | |
| address externalId = address(new_contract); | |
| BuilderShops[externalId] = true; | |
| emit BuilderInstanceCreated(externalId, contractId); | |
| return (new_contract); | |
| } | |
| } | |
| /* | |
| * @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 GSN 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. | |
| */ | |
| contract Context { | |
| // Empty internal constructor, to prevent people from mistakenly deploying | |
| // an instance of this contract, which should be used via inheritance. | |
| constructor () internal { } | |
| // solhint-disable-previous-line no-empty-blocks | |
| function _msgSender() internal view returns (address payable) { | |
| return msg.sender; | |
| } | |
| function _msgData() internal view returns (bytes memory) { | |
| this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691 | |
| return msg.data; | |
| } | |
| } | |
| /** | |
| * @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); | |
| } | |
| /** | |
| * @dev Implementation of the {IERC165} interface. | |
| * | |
| * Contracts may inherit from this and call {_registerInterface} to declare | |
| * their support of an interface. | |
| */ | |
| contract ERC165 is IERC165 { | |
| /* | |
| * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7 | |
| */ | |
| bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7; | |
| /** | |
| * @dev Mapping of interface ids to whether or not it's supported. | |
| */ | |
| mapping(bytes4 => bool) private _supportedInterfaces; | |
| constructor () internal { | |
| // Derived contracts need only register support for their own interfaces, | |
| // we register support for ERC165 itself here | |
| _registerInterface(_INTERFACE_ID_ERC165); | |
| } | |
| /** | |
| * @dev See {IERC165-supportsInterface}. | |
| * | |
| * Time complexity O(1), guaranteed to always use less than 30 000 gas. | |
| */ | |
| function supportsInterface(bytes4 interfaceId) external view returns (bool) { | |
| return _supportedInterfaces[interfaceId]; | |
| } | |
| /** | |
| * @dev Registers the contract as an implementer of the interface defined by | |
| * `interfaceId`. Support of the actual ERC165 interface is automatic and | |
| * registering its interface id is not required. | |
| * | |
| * See {IERC165-supportsInterface}. | |
| * | |
| * Requirements: | |
| * | |
| * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`). | |
| */ | |
| function _registerInterface(bytes4 interfaceId) internal { | |
| require(interfaceId != 0xffffffff, "ERC165: invalid interface id"); | |
| _supportedInterfaces[interfaceId] = true; | |
| } | |
| } | |
| /** | |
| * @dev Required interface of an ERC721 compliant contract. | |
| */ | |
| contract IERC721 is IERC165 { | |
| event Transfer(address indexed from, address indexed to, uint256 indexed tokenId); | |
| event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId); | |
| event ApprovalForAll(address indexed owner, address indexed operator, bool approved); | |
| /** | |
| * @dev Returns the number of NFTs in `owner`'s account. | |
| */ | |
| function balanceOf(address owner) public view returns (uint256 balance); | |
| /** | |
| * @dev Returns the owner of the NFT specified by `tokenId`. | |
| */ | |
| function ownerOf(uint256 tokenId) public view returns (address owner); | |
| /** | |
| * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to | |
| * another (`to`). | |
| * | |
| * | |
| * | |
| * Requirements: | |
| * - `from`, `to` cannot be zero. | |
| * - `tokenId` must be owned by `from`. | |
| * - If the caller is not `from`, it must be have been allowed to move this | |
| * NFT by either {approve} or {setApprovalForAll}. | |
| */ | |
| function safeTransferFrom(address from, address to, uint256 tokenId) public; | |
| /** | |
| * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to | |
| * another (`to`). | |
| * | |
| * Requirements: | |
| * - If the caller is not `from`, it must be approved to move this NFT by | |
| * either {approve} or {setApprovalForAll}. | |
| */ | |
| function transferFrom(address from, address to, uint256 tokenId) public; | |
| function approve(address to, uint256 tokenId) public; | |
| function getApproved(uint256 tokenId) public view returns (address operator); | |
| function setApprovalForAll(address operator, bool _approved) public; | |
| function isApprovedForAll(address owner, address operator) public view returns (bool); | |
| function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public; | |
| } | |
| /** | |
| * @title ERC721 token receiver interface | |
| * @dev Interface for any contract that wants to support safeTransfers | |
| * from ERC721 asset contracts. | |
| */ | |
| contract IERC721Receiver { | |
| /** | |
| * @notice Handle the receipt of an NFT | |
| * @dev The ERC721 smart contract calls this function on the recipient | |
| * after a {IERC721-safeTransferFrom}. This function MUST return the function selector, | |
| * otherwise the caller will revert the transaction. The selector to be | |
| * returned can be obtained as `this.onERC721Received.selector`. This | |
| * function MAY throw to revert and reject the transfer. | |
| * Note: the ERC721 contract address is always the message sender. | |
| * @param operator The address which called `safeTransferFrom` function | |
| * @param from The address which previously owned the token | |
| * @param tokenId The NFT identifier which is being transferred | |
| * @param data Additional data with no specified format | |
| * @return bytes4 `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))` | |
| */ | |
| function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data) | |
| public returns (bytes4); | |
| } | |
| /** | |
| * @title ERC721 Non-Fungible Token Standard basic implementation | |
| * @dev see https://eips.ethereum.org/EIPS/eip-721 | |
| */ | |
| contract ERC721 is Context, ERC165, IERC721 { | |
| using SafeMath for uint256; | |
| using Address for address; | |
| using Counters for Counters.Counter; | |
| // Equals to `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))` | |
| // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector` | |
| bytes4 private constant _ERC721_RECEIVED = 0x150b7a02; | |
| // Mapping from token ID to owner | |
| mapping (uint256 => address) private _tokenOwner; | |
| // Mapping from token ID to approved address | |
| mapping (uint256 => address) private _tokenApprovals; | |
| // Mapping from owner to number of owned token | |
| mapping (address => Counters.Counter) private _ownedTokensCount; | |
| // Mapping from owner to operator approvals | |
| mapping (address => mapping (address => bool)) private _operatorApprovals; | |
| /* | |
| * bytes4(keccak256('balanceOf(address)')) == 0x70a08231 | |
| * bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e | |
| * bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3 | |
| * bytes4(keccak256('getApproved(uint256)')) == 0x081812fc | |
| * bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465 | |
| * bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c5 | |
| * bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd | |
| * bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e | |
| * bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde | |
| * | |
| * => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^ | |
| * 0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd | |
| */ | |
| bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd; | |
| constructor () public { | |
| // register the supported interfaces to conform to ERC721 via ERC165 | |
| _registerInterface(_INTERFACE_ID_ERC721); | |
| } | |
| /** | |
| * @dev Gets the balance of the specified address. | |
| * @param owner address to query the balance of | |
| * @return uint256 representing the amount owned by the passed address | |
| */ | |
| function balanceOf(address owner) public view returns (uint256) { | |
| require(owner != address(0), "ERC721: balance query for the zero address"); | |
| return _ownedTokensCount[owner].current(); | |
| } | |
| /** | |
| * @dev Gets the owner of the specified token ID. | |
| * @param tokenId uint256 ID of the token to query the owner of | |
| * @return address currently marked as the owner of the given token ID | |
| */ | |
| function ownerOf(uint256 tokenId) public view returns (address) { | |
| address owner = _tokenOwner[tokenId]; | |
| require(owner != address(0), "ERC721: owner query for nonexistent token"); | |
| return owner; | |
| } | |
| /** | |
| * @dev Approves another address to transfer the given token ID | |
| * The zero address indicates there is no approved address. | |
| * There can only be one approved address per token at a given time. | |
| * Can only be called by the token owner or an approved operator. | |
| * @param to address to be approved for the given token ID | |
| * @param tokenId uint256 ID of the token to be approved | |
| */ | |
| function approve(address to, uint256 tokenId) public { | |
| address owner = ownerOf(tokenId); | |
| require(to != owner, "ERC721: approval to current owner"); | |
| require(_msgSender() == owner || isApprovedForAll(owner, _msgSender()), | |
| "ERC721: approve caller is not owner nor approved for all" | |
| ); | |
| _tokenApprovals[tokenId] = to; | |
| emit Approval(owner, to, tokenId); | |
| } | |
| /** | |
| * @dev Gets the approved address for a token ID, or zero if no address set | |
| * Reverts if the token ID does not exist. | |
| * @param tokenId uint256 ID of the token to query the approval of | |
| * @return address currently approved for the given token ID | |
| */ | |
| function getApproved(uint256 tokenId) public view returns (address) { | |
| require(_exists(tokenId), "ERC721: approved query for nonexistent token"); | |
| return _tokenApprovals[tokenId]; | |
| } | |
| /** | |
| * @dev Sets or unsets the approval of a given operator | |
| * An operator is allowed to transfer all tokens of the sender on their behalf. | |
| * @param to operator address to set the approval | |
| * @param approved representing the status of the approval to be set | |
| */ | |
| function setApprovalForAll(address to, bool approved) public { | |
| require(to != _msgSender(), "ERC721: approve to caller"); | |
| _operatorApprovals[_msgSender()][to] = approved; | |
| emit ApprovalForAll(_msgSender(), to, approved); | |
| } | |
| /** | |
| * @dev Tells whether an operator is approved by a given owner. | |
| * @param owner owner address which you want to query the approval of | |
| * @param operator operator address which you want to query the approval of | |
| * @return bool whether the given operator is approved by the given owner | |
| */ | |
| function isApprovedForAll(address owner, address operator) public view returns (bool) { | |
| return _operatorApprovals[owner][operator]; | |
| } | |
| /** | |
| * @dev Transfers the ownership of a given token ID to another address. | |
| * Usage of this method is discouraged, use {safeTransferFrom} whenever possible. | |
| * Requires the msg.sender to be the owner, approved, or operator. | |
| * @param from current owner of the token | |
| * @param to address to receive the ownership of the given token ID | |
| * @param tokenId uint256 ID of the token to be transferred | |
| */ | |
| function transferFrom(address from, address to, uint256 tokenId) public { | |
| //solhint-disable-next-line max-line-length | |
| require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved"); | |
| _transferFrom(from, to, tokenId); | |
| } | |
| /** | |
| * @dev Safely transfers the ownership of a given token ID to another address | |
| * If the target address is a contract, it must implement {IERC721Receiver-onERC721Received}, | |
| * which is called upon a safe transfer, and return the magic value | |
| * `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise, | |
| * the transfer is reverted. | |
| * Requires the msg.sender to be the owner, approved, or operator | |
| * @param from current owner of the token | |
| * @param to address to receive the ownership of the given token ID | |
| * @param tokenId uint256 ID of the token to be transferred | |
| */ | |
| function safeTransferFrom(address from, address to, uint256 tokenId) public { | |
| safeTransferFrom(from, to, tokenId, ""); | |
| } | |
| /** | |
| * @dev Safely transfers the ownership of a given token ID to another address | |
| * If the target address is a contract, it must implement {IERC721Receiver-onERC721Received}, | |
| * which is called upon a safe transfer, and return the magic value | |
| * `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise, | |
| * the transfer is reverted. | |
| * Requires the _msgSender() to be the owner, approved, or operator | |
| * @param from current owner of the token | |
| * @param to address to receive the ownership of the given token ID | |
| * @param tokenId uint256 ID of the token to be transferred | |
| * @param _data bytes data to send along with a safe transfer check | |
| */ | |
| function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public { | |
| require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved"); | |
| _safeTransferFrom(from, to, tokenId, _data); | |
| } | |
| /** | |
| * @dev Safely transfers the ownership of a given token ID to another address | |
| * If the target address is a contract, it must implement `onERC721Received`, | |
| * which is called upon a safe transfer, and return the magic value | |
| * `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise, | |
| * the transfer is reverted. | |
| * Requires the msg.sender to be the owner, approved, or operator | |
| * @param from current owner of the token | |
| * @param to address to receive the ownership of the given token ID | |
| * @param tokenId uint256 ID of the token to be transferred | |
| * @param _data bytes data to send along with a safe transfer check | |
| */ | |
| function _safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) internal { | |
| _transferFrom(from, to, tokenId); | |
| require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer"); | |
| } | |
| /** | |
| * @dev Returns whether the specified token exists. | |
| * @param tokenId uint256 ID of the token to query the existence of | |
| * @return bool whether the token exists | |
| */ | |
| function _exists(uint256 tokenId) internal view returns (bool) { | |
| address owner = _tokenOwner[tokenId]; | |
| return owner != address(0); | |
| } | |
| /** | |
| * @dev Returns whether the given spender can transfer a given token ID. | |
| * @param spender address of the spender to query | |
| * @param tokenId uint256 ID of the token to be transferred | |
| * @return bool whether the msg.sender is approved for the given token ID, | |
| * is an operator of the owner, or is the owner of the token | |
| */ | |
| function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) { | |
| require(_exists(tokenId), "ERC721: operator query for nonexistent token"); | |
| address owner = ownerOf(tokenId); | |
| return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender)); | |
| } | |
| /** | |
| * @dev Internal function to safely mint a new token. | |
| * Reverts if the given token ID already exists. | |
| * If the target address is a contract, it must implement `onERC721Received`, | |
| * which is called upon a safe transfer, and return the magic value | |
| * `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise, | |
| * the transfer is reverted. | |
| * @param to The address that will own the minted token | |
| * @param tokenId uint256 ID of the token to be minted | |
| */ | |
| function _safeMint(address to, uint256 tokenId) internal { | |
| _safeMint(to, tokenId, ""); | |
| } | |
| /** | |
| * @dev Internal function to safely mint a new token. | |
| * Reverts if the given token ID already exists. | |
| * If the target address is a contract, it must implement `onERC721Received`, | |
| * which is called upon a safe transfer, and return the magic value | |
| * `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise, | |
| * the transfer is reverted. | |
| * @param to The address that will own the minted token | |
| * @param tokenId uint256 ID of the token to be minted | |
| * @param _data bytes data to send along with a safe transfer check | |
| */ | |
| function _safeMint(address to, uint256 tokenId, bytes memory _data) internal { | |
| _mint(to, tokenId); | |
| require(_checkOnERC721Received(address(0), to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer"); | |
| } | |
| /** | |
| * @dev Internal function to mint a new token. | |
| * Reverts if the given token ID already exists. | |
| * @param to The address that will own the minted token | |
| * @param tokenId uint256 ID of the token to be minted | |
| */ | |
| function _mint(address to, uint256 tokenId) internal { | |
| require(to != address(0), "ERC721: mint to the zero address"); | |
| require(!_exists(tokenId), "ERC721: token already minted"); | |
| _tokenOwner[tokenId] = to; | |
| _ownedTokensCount[to].increment(); | |
| emit Transfer(address(0), to, tokenId); | |
| } | |
| /** | |
| * @dev Internal function to burn a specific token. | |
| * Reverts if the token does not exist. | |
| * Deprecated, use {_burn} instead. | |
| * @param owner owner of the token to burn | |
| * @param tokenId uint256 ID of the token being burned | |
| */ | |
| function _burn(address owner, uint256 tokenId) internal { | |
| require(ownerOf(tokenId) == owner, "ERC721: burn of token that is not own"); | |
| _clearApproval(tokenId); | |
| _ownedTokensCount[owner].decrement(); | |
| _tokenOwner[tokenId] = address(0); | |
| emit Transfer(owner, address(0), tokenId); | |
| } | |
| /** | |
| * @dev Internal function to burn a specific token. | |
| * Reverts if the token does not exist. | |
| * @param tokenId uint256 ID of the token being burned | |
| */ | |
| function _burn(uint256 tokenId) internal { | |
| _burn(ownerOf(tokenId), tokenId); | |
| } | |
| /** | |
| * @dev Internal function to transfer ownership of a given token ID to another address. | |
| * As opposed to {transferFrom}, this imposes no restrictions on msg.sender. | |
| * @param from current owner of the token | |
| * @param to address to receive the ownership of the given token ID | |
| * @param tokenId uint256 ID of the token to be transferred | |
| */ | |
| function _transferFrom(address from, address to, uint256 tokenId) internal { | |
| require(ownerOf(tokenId) == from, "ERC721: transfer of token that is not own"); | |
| require(to != address(0), "ERC721: transfer to the zero address"); | |
| _clearApproval(tokenId); | |
| _ownedTokensCount[from].decrement(); | |
| _ownedTokensCount[to].increment(); | |
| _tokenOwner[tokenId] = to; | |
| emit Transfer(from, to, tokenId); | |
| } | |
| /** | |
| * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address. | |
| * The call is not executed if the target address is not a contract. | |
| * | |
| * This function is deprecated. | |
| * @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) | |
| internal returns (bool) | |
| { | |
| if (!to.isContract()) { | |
| return true; | |
| } | |
| bytes4 retval = IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data); | |
| return (retval == _ERC721_RECEIVED); | |
| } | |
| /** | |
| * @dev Private function to clear current approval of a given token ID. | |
| * @param tokenId uint256 ID of the token to be transferred | |
| */ | |
| function _clearApproval(uint256 tokenId) private { | |
| if (_tokenApprovals[tokenId] != address(0)) { | |
| _tokenApprovals[tokenId] = address(0); | |
| } | |
| } | |
| } | |
| /** | |
| * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension | |
| * @dev See https://eips.ethereum.org/EIPS/eip-721 | |
| */ | |
| contract IERC721Enumerable is IERC721 { | |
| function totalSupply() public view returns (uint256); | |
| function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId); | |
| function tokenByIndex(uint256 index) public view returns (uint256); | |
| } | |
| /** | |
| * @title ERC-721 Non-Fungible Token with optional enumeration extension logic | |
| * @dev See https://eips.ethereum.org/EIPS/eip-721 | |
| */ | |
| contract ERC721Enumerable is Context, ERC165, ERC721, IERC721Enumerable { | |
| // Mapping from owner to list of owned token IDs | |
| mapping(address => uint256[]) private _ownedTokens; | |
| // Mapping from token ID to index of the owner tokens list | |
| mapping(uint256 => uint256) private _ownedTokensIndex; | |
| // Array with all token ids, used for enumeration | |
| uint256[] private _allTokens; | |
| // Mapping from token id to position in the allTokens array | |
| mapping(uint256 => uint256) private _allTokensIndex; | |
| /* | |
| * bytes4(keccak256('totalSupply()')) == 0x18160ddd | |
| * bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59 | |
| * bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7 | |
| * | |
| * => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63 | |
| */ | |
| bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63; | |
| /** | |
| * @dev Constructor function. | |
| */ | |
| constructor () public { | |
| // register the supported interface to conform to ERC721Enumerable via ERC165 | |
| _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE); | |
| } | |
| /** | |
| * @dev Gets the token ID at a given index of the tokens list of the requested owner. | |
| * @param owner address owning the tokens list to be accessed | |
| * @param index uint256 representing the index to be accessed of the requested tokens list | |
| * @return uint256 token ID at the given index of the tokens list owned by the requested address | |
| */ | |
| function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) { | |
| require(index < balanceOf(owner), "ERC721Enumerable: owner index out of bounds"); | |
| return _ownedTokens[owner][index]; | |
| } | |
| /** | |
| * @dev Gets the total amount of tokens stored by the contract. | |
| * @return uint256 representing the total amount of tokens | |
| */ | |
| function totalSupply() public view returns (uint256) { | |
| return _allTokens.length; | |
| } | |
| /** | |
| * @dev Gets the token ID at a given index of all the tokens in this contract | |
| * Reverts if the index is greater or equal to the total number of tokens. | |
| * @param index uint256 representing the index to be accessed of the tokens list | |
| * @return uint256 token ID at the given index of the tokens list | |
| */ | |
| function tokenByIndex(uint256 index) public view returns (uint256) { | |
| require(index < totalSupply(), "ERC721Enumerable: global index out of bounds"); | |
| return _allTokens[index]; | |
| } | |
| /** | |
| * @dev Internal function to transfer ownership of a given token ID to another address. | |
| * As opposed to transferFrom, this imposes no restrictions on msg.sender. | |
| * @param from current owner of the token | |
| * @param to address to receive the ownership of the given token ID | |
| * @param tokenId uint256 ID of the token to be transferred | |
| */ | |
| function _transferFrom(address from, address to, uint256 tokenId) internal { | |
| super._transferFrom(from, to, tokenId); | |
| _removeTokenFromOwnerEnumeration(from, tokenId); | |
| _addTokenToOwnerEnumeration(to, tokenId); | |
| } | |
| /** | |
| * @dev Internal function to mint a new token. | |
| * Reverts if the given token ID already exists. | |
| * @param to address the beneficiary that will own the minted token | |
| * @param tokenId uint256 ID of the token to be minted | |
| */ | |
| function _mint(address to, uint256 tokenId) internal { | |
| super._mint(to, tokenId); | |
| _addTokenToOwnerEnumeration(to, tokenId); | |
| _addTokenToAllTokensEnumeration(tokenId); | |
| } | |
| /** | |
| * @dev Internal function to burn a specific token. | |
| * Reverts if the token does not exist. | |
| * Deprecated, use {ERC721-_burn} instead. | |
| * @param owner owner of the token to burn | |
| * @param tokenId uint256 ID of the token being burned | |
| */ | |
| function _burn(address owner, uint256 tokenId) internal { | |
| super._burn(owner, tokenId); | |
| _removeTokenFromOwnerEnumeration(owner, tokenId); | |
| // Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund | |
| _ownedTokensIndex[tokenId] = 0; | |
| _removeTokenFromAllTokensEnumeration(tokenId); | |
| } | |
| /** | |
| * @dev Gets the list of token IDs of the requested owner. | |
| * @param owner address owning the tokens | |
| * @return uint256[] List of token IDs owned by the requested address | |
| */ | |
| function _tokensOfOwner(address owner) internal view returns (uint256[] storage) { | |
| return _ownedTokens[owner]; | |
| } | |
| /** | |
| * @dev Private function to add a token to this extension's ownership-tracking data structures. | |
| * @param to address representing the new owner of the given token ID | |
| * @param tokenId uint256 ID of the token to be added to the tokens list of the given address | |
| */ | |
| function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private { | |
| _ownedTokensIndex[tokenId] = _ownedTokens[to].length; | |
| _ownedTokens[to].push(tokenId); | |
| } | |
| /** | |
| * @dev Private function to add a token to this extension's token tracking data structures. | |
| * @param tokenId uint256 ID of the token to be added to the tokens list | |
| */ | |
| function _addTokenToAllTokensEnumeration(uint256 tokenId) private { | |
| _allTokensIndex[tokenId] = _allTokens.length; | |
| _allTokens.push(tokenId); | |
| } | |
| /** | |
| * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that | |
| * while the token is not assigned a new owner, the `_ownedTokensIndex` mapping is _not_ updated: this allows for | |
| * gas optimizations e.g. when performing a transfer operation (avoiding double writes). | |
| * This has O(1) time complexity, but alters the order of the _ownedTokens array. | |
| * @param from address representing the previous owner of the given token ID | |
| * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address | |
| */ | |
| function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private { | |
| // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and | |
| // then delete the last slot (swap and pop). | |
| uint256 lastTokenIndex = _ownedTokens[from].length.sub(1); | |
| uint256 tokenIndex = _ownedTokensIndex[tokenId]; | |
| // When the token to delete is the last token, the swap operation is unnecessary | |
| if (tokenIndex != lastTokenIndex) { | |
| uint256 lastTokenId = _ownedTokens[from][lastTokenIndex]; | |
| _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token | |
| _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index | |
| } | |
| // This also deletes the contents at the last position of the array | |
| _ownedTokens[from].length--; | |
| // Note that _ownedTokensIndex[tokenId] hasn't been cleared: it still points to the old slot (now occupied by | |
| // lastTokenId, or just over the end of the array if the token was the last one). | |
| } | |
| /** | |
| * @dev Private function to remove a token from this extension's token tracking data structures. | |
| * This has O(1) time complexity, but alters the order of the _allTokens array. | |
| * @param tokenId uint256 ID of the token to be removed from the tokens list | |
| */ | |
| function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private { | |
| // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and | |
| // then delete the last slot (swap and pop). | |
| uint256 lastTokenIndex = _allTokens.length.sub(1); | |
| uint256 tokenIndex = _allTokensIndex[tokenId]; | |
| // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so | |
| // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding | |
| // an 'if' statement (like in _removeTokenFromOwnerEnumeration) | |
| uint256 lastTokenId = _allTokens[lastTokenIndex]; | |
| _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token | |
| _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index | |
| // This also deletes the contents at the last position of the array | |
| _allTokens.length--; | |
| _allTokensIndex[tokenId] = 0; | |
| } | |
| } | |
| /** | |
| * @title ERC-721 Non-Fungible Token Standard, optional metadata extension | |
| * @dev See https://eips.ethereum.org/EIPS/eip-721 | |
| */ | |
| contract IERC721Metadata is IERC721 { | |
| function name() external view returns (string memory); | |
| function symbol() external view returns (string memory); | |
| function tokenURI(uint256 tokenId) external view returns (string memory); | |
| } | |
| contract ERC721Metadata is Context, ERC165, ERC721, IERC721Metadata { | |
| // Token name | |
| string private _name; | |
| // Token symbol | |
| string private _symbol; | |
| // Optional mapping for token URIs | |
| mapping(uint256 => string) private _tokenURIs; | |
| //Optional mapping for IPFS link to canonical image file | |
| mapping(uint256 => string) private _tokenIPFSHashes; | |
| /* | |
| * bytes4(keccak256('name()')) == 0x06fdde03 | |
| * bytes4(keccak256('symbol()')) == 0x95d89b41 | |
| * bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd | |
| * | |
| * => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f | |
| */ | |
| bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f; | |
| /** | |
| * @dev Constructor function | |
| */ | |
| constructor (string memory name, string memory symbol) public { | |
| _name = name; | |
| _symbol = symbol; | |
| // register the supported interfaces to conform to ERC721 via ERC165 | |
| _registerInterface(_INTERFACE_ID_ERC721_METADATA); | |
| } | |
| /** | |
| * @dev Gets the token name. | |
| * @return string representing the token name | |
| */ | |
| function name() external view returns (string memory) { | |
| return _name; | |
| } | |
| /** | |
| * @dev Gets the token symbol. | |
| * @return string representing the token symbol | |
| */ | |
| function symbol() external view returns (string memory) { | |
| return _symbol; | |
| } | |
| /** | |
| * @dev Returns an URI for a given token ID. | |
| * Throws if the token ID does not exist. May return an empty string. | |
| * @param tokenId uint256 ID of the token to query | |
| */ | |
| function tokenURI(uint256 tokenId) external view returns (string memory) { | |
| require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token"); | |
| return _tokenURIs[tokenId]; | |
| } | |
| /** | |
| * @dev Returns an URI for a given token ID. | |
| * Throws if the token ID does not exist. May return an empty string. | |
| * @param tokenId uint256 ID of the token to query | |
| */ | |
| function tokenIPFSHash(uint256 tokenId) external view returns (string memory) { | |
| require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token"); | |
| return _tokenIPFSHashes[tokenId]; | |
| } | |
| /** | |
| * @dev Internal function to set the token URI for a given token. | |
| * Reverts if the token ID does not exist. | |
| * @param tokenId uint256 ID of the token to set its URI | |
| * @param uri string URI to assign | |
| */ | |
| function _setTokenURI(uint256 tokenId, string memory uri) internal { | |
| require(_exists(tokenId), "ERC721Metadata: URI set of nonexistent token"); | |
| _tokenURIs[tokenId] = uri; | |
| } | |
| /** | |
| * @dev Internal function to set the token IPFS hash for a given token. | |
| * Reverts if the token ID does not exist. | |
| * @param tokenId uint256 ID of the token to set its URI | |
| * @param ipfs_hash string IPFS link to assign | |
| */ | |
| function _setTokenIPFSHash(uint256 tokenId, string memory ipfs_hash) internal { | |
| require(_exists(tokenId), "ERC721Metadata: URI set of nonexistent token"); | |
| _tokenIPFSHashes[tokenId] = ipfs_hash; | |
| } | |
| /** | |
| * @dev Internal function to burn a specific token. | |
| * Reverts if the token does not exist. | |
| * Deprecated, use _burn(uint256) instead. | |
| * @param owner owner of the token to burn | |
| * @param tokenId uint256 ID of the token being burned by the msg.sender | |
| */ | |
| function _burn(address owner, uint256 tokenId) internal { | |
| super._burn(owner, tokenId); | |
| // Clear metadata (if any) | |
| if (bytes(_tokenURIs[tokenId]).length != 0) { | |
| delete _tokenURIs[tokenId]; | |
| } | |
| } | |
| } | |
| /** | |
| * @title Full ERC721 Token | |
| * @dev This implementation includes all the required and some optional functionality of the ERC721 standard | |
| * Moreover, it includes approve all functionality using operator terminology. | |
| * | |
| * See https://eips.ethereum.org/EIPS/eip-721 | |
| */ | |
| contract ERC721Full is ERC721, ERC721Enumerable, ERC721Metadata { | |
| constructor (string memory name, string memory symbol) public ERC721Metadata(name, symbol) { | |
| // solhint-disable-previous-line no-empty-blocks | |
| } | |
| } | |
| contract NiftyBuilderInstance is ERC721Full { | |
| //MODIFIERS | |
| modifier onlyValidSender() { | |
| NiftyRegistry nftg_registry = NiftyRegistry(niftyRegistryContract); | |
| bool is_valid = nftg_registry.isValidNiftySender(msg.sender); | |
| require(is_valid==true); | |
| _; | |
| } | |
| //CONSTANTS | |
| // how many nifties this contract is selling | |
| // used for metadat retrieval | |
| uint public numNiftiesCurrentlyInContract; | |
| //id of this contract for metadata server | |
| uint public contractId; | |
| //is permanently closed | |
| bool public isClosed = false; | |
| //baseURI for metadata server | |
| string public baseURI; | |
| // //name of creator | |
| // string public creatorName; | |
| string public nameOfCreator; | |
| //nifty registry contract | |
| address public niftyRegistryContract = 0x6e53130dDfF21E3BC963Ee902005223b9A202106; | |
| //master builder - ONLY DOES STATIC CALLS | |
| address public masterBuilderContract = 0x6EFB06cF568253a53C7511BD3c31AB28BecB0192; | |
| using Counters for Counters.Counter; | |
| //MAPPINGS | |
| //mappings for token Ids | |
| mapping (uint => Counters.Counter) public _numNiftyMinted; | |
| mapping (uint => uint) public _niftyPrice; | |
| mapping (uint => string) public _niftyIPFSHashes; | |
| mapping (uint => bool) public _IPFSHashHasBeenSet; | |
| //EVENTS | |
| //purchase + creation events | |
| event NiftyPurchased(address _buyer, uint256 _amount, uint _tokenId); | |
| event NiftyCreated(address new_owner, uint _niftyType, uint _tokenId); | |
| //CONSTRUCTOR FUNCTION | |
| constructor( | |
| string memory _name, | |
| string memory _symbol, | |
| uint contract_id, | |
| uint num_nifties, | |
| string memory base_uri, | |
| string memory name_of_creator) ERC721Full(_name, _symbol) public { | |
| //set local variables based on inputs | |
| contractId = contract_id; | |
| numNiftiesCurrentlyInContract = num_nifties; | |
| baseURI = base_uri; | |
| nameOfCreator = name_of_creator; | |
| //offset starts at 1 - there is no niftyType of 0 | |
| // for (uint i=0; i<(num_nifties); i++) { | |
| // _numNiftyPermitted[i+1] = nifty_quantities[i]; | |
| // } | |
| } | |
| function setNiftyIPFSHash(uint niftyType, | |
| string memory ipfs_hash) onlyValidSender public { | |
| //can only be set once | |
| if (_IPFSHashHasBeenSet[niftyType] == true) { | |
| revert("Can only be set once"); | |
| } else { | |
| _niftyIPFSHashes[niftyType] = ipfs_hash; | |
| _IPFSHashHasBeenSet[niftyType] = true; | |
| } | |
| } | |
| function closeContract() onlyValidSender public { | |
| //permanently close this open edition | |
| isClosed = true; | |
| } | |
| function giftNifty(address collector_address, | |
| uint niftyType) onlyValidSender public { | |
| //master for static calls | |
| BuilderMaster bm = BuilderMaster(masterBuilderContract); | |
| _numNiftyMinted[niftyType].increment(); | |
| //check if this collection is closed | |
| if (isClosed==true) { | |
| revert("This contract is closed!"); | |
| } | |
| //mint a nifty | |
| uint specificTokenId = _numNiftyMinted[niftyType].current(); | |
| uint tokenId = bm.encodeTokenId(contractId, niftyType, specificTokenId); | |
| string memory tokenIdStr = bm.uint2str(tokenId); | |
| string memory tokenURI = bm.strConcat(baseURI, tokenIdStr); | |
| string memory ipfsHash = _niftyIPFSHashes[niftyType]; | |
| //mint token | |
| _mint(collector_address, tokenId); | |
| _setTokenURI(tokenId, tokenURI); | |
| _setTokenIPFSHash(tokenId, ipfsHash); | |
| //do events | |
| emit NiftyCreated(collector_address, niftyType, tokenId); | |
| } | |
| } | |
| contract NiftyRegistry { | |
| function isValidNiftySender(address sending_key) public view returns (bool); | |
| function isOwner(address owner_key) public view returns (bool); | |
| } | |
| contract BuilderMaster { | |
| function getContractId(uint tokenId) public view returns (uint); | |
| function getNiftyTypeId(uint tokenId) public view returns (uint); | |
| function getSpecificNiftyNum(uint tokenId) public view returns (uint); | |
| function encodeTokenId(uint contractId, uint niftyType, uint specificNiftyNum) public view returns (uint); | |
| function strConcat(string memory _a, string memory _b, string memory _c, string memory _d, string memory _e) public view returns (string memory); | |
| function strConcat(string memory _a, string memory _b, string memory _c, string memory _d) public view returns (string memory); | |
| function strConcat(string memory _a, string memory _b, string memory _c) public view returns (string memory); | |
| function strConcat(string memory _a, string memory _b) public view returns (string memory); | |
| function uint2str(uint _i) public view returns (string memory _uintAsString); | |
| } | |
| /** | |
| * Contracts and libraries below are from OpenZeppelin, except nifty builder instance | |
| **/ | |
| /** | |
| * @dev Wrappers over Solidity's arithmetic operations with added overflow | |
| * checks. | |
| * | |
| * Arithmetic operations in Solidity wrap on overflow. This can easily result | |
| * in bugs, because programmers usually assume that an overflow raises an | |
| * error, which is the standard behavior in high level programming languages. | |
| * `SafeMath` restores this intuition by reverting the transaction when an | |
| * operation overflows. | |
| * | |
| * Using this library instead of the unchecked operations eliminates an entire | |
| * class of bugs, so it's recommended to use it always. | |
| */ | |
| library SafeMath { | |
| /** | |
| * @dev Returns the addition of two unsigned integers, reverting on | |
| * overflow. | |
| * | |
| * Counterpart to Solidity's `+` operator. | |
| * | |
| * Requirements: | |
| * - Addition cannot overflow. | |
| */ | |
| function add(uint256 a, uint256 b) internal pure returns (uint256) { | |
| uint256 c = a + b; | |
| require(c >= a, "SafeMath: addition overflow"); | |
| return c; | |
| } | |
| /** | |
| * @dev Returns the subtraction of two unsigned integers, reverting on | |
| * overflow (when the result is negative). | |
| * | |
| * Counterpart to Solidity's `-` operator. | |
| * | |
| * Requirements: | |
| * - Subtraction cannot overflow. | |
| */ | |
| function sub(uint256 a, uint256 b) internal pure returns (uint256) { | |
| return sub(a, b, "SafeMath: subtraction overflow"); | |
| } | |
| /** | |
| * @dev Returns the subtraction of two unsigned integers, reverting with custom message on | |
| * overflow (when the result is negative). | |
| * | |
| * Counterpart to Solidity's `-` operator. | |
| * | |
| * Requirements: | |
| * - Subtraction cannot overflow. | |
| * | |
| * NOTE: This is a feature of the next version of OpenZeppelin Contracts. | |
| * @dev Get it via `npm install @openzeppelin/contracts@next`. | |
| */ | |
| function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { | |
| require(b <= a, errorMessage); | |
| uint256 c = a - b; | |
| return c; | |
| } | |
| /** | |
| * @dev Returns the multiplication of two unsigned integers, reverting on | |
| * overflow. | |
| * | |
| * Counterpart to Solidity's `*` operator. | |
| * | |
| * Requirements: | |
| * - Multiplication cannot overflow. | |
| */ | |
| function mul(uint256 a, uint256 b) internal pure returns (uint256) { | |
| // Gas optimization: this is cheaper than requiring 'a' not being zero, but the | |
| // benefit is lost if 'b' is also tested. | |
| // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522 | |
| if (a == 0) { | |
| return 0; | |
| } | |
| uint256 c = a * b; | |
| require(c / a == b, "SafeMath: multiplication overflow"); | |
| return c; | |
| } | |
| /** | |
| * @dev Returns the integer division of two unsigned integers. Reverts on | |
| * division by zero. The result is rounded towards zero. | |
| * | |
| * Counterpart to Solidity's `/` operator. Note: this function uses a | |
| * `revert` opcode (which leaves remaining gas untouched) while Solidity | |
| * uses an invalid opcode to revert (consuming all remaining gas). | |
| * | |
| * Requirements: | |
| * - The divisor cannot be zero. | |
| */ | |
| function div(uint256 a, uint256 b) internal pure returns (uint256) { | |
| return div(a, b, "SafeMath: division by zero"); | |
| } | |
| /** | |
| * @dev Returns the integer division of two unsigned integers. Reverts with custom message on | |
| * division by zero. The result is rounded towards zero. | |
| * | |
| * Counterpart to Solidity's `/` operator. Note: this function uses a | |
| * `revert` opcode (which leaves remaining gas untouched) while Solidity | |
| * uses an invalid opcode to revert (consuming all remaining gas). | |
| * | |
| * Requirements: | |
| * - The divisor cannot be zero. | |
| * NOTE: This is a feature of the next version of OpenZeppelin Contracts. | |
| * @dev Get it via `npm install @openzeppelin/contracts@next`. | |
| */ | |
| function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { | |
| // Solidity only automatically asserts when dividing by 0 | |
| require(b > 0, errorMessage); | |
| uint256 c = a / b; | |
| // assert(a == b * c + a % b); // There is no case in which this doesn't hold | |
| return c; | |
| } | |
| /** | |
| * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), | |
| * Reverts when dividing by zero. | |
| * | |
| * Counterpart to Solidity's `%` operator. This function uses a `revert` | |
| * opcode (which leaves remaining gas untouched) while Solidity uses an | |
| * invalid opcode to revert (consuming all remaining gas). | |
| * | |
| * Requirements: | |
| * - The divisor cannot be zero. | |
| */ | |
| function mod(uint256 a, uint256 b) internal pure returns (uint256) { | |
| return mod(a, b, "SafeMath: modulo by zero"); | |
| } | |
| /** | |
| * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), | |
| * Reverts with custom message when dividing by zero. | |
| * | |
| * Counterpart to Solidity's `%` operator. This function uses a `revert` | |
| * opcode (which leaves remaining gas untouched) while Solidity uses an | |
| * invalid opcode to revert (consuming all remaining gas). | |
| * | |
| * Requirements: | |
| * - The divisor cannot be zero. | |
| * | |
| * NOTE: This is a feature of the next version of OpenZeppelin Contracts. | |
| * @dev Get it via `npm install @openzeppelin/contracts@next`. | |
| */ | |
| function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { | |
| require(b != 0, errorMessage); | |
| return a % b; | |
| } | |
| } | |
| /** | |
| * @dev Collection of functions related to the address type | |
| */ | |
| library Address { | |
| /** | |
| * @dev Returns true if `account` is a contract. | |
| * | |
| * This test is non-exhaustive, and there may be false-negatives: during the | |
| * execution of a contract's constructor, its address will be reported as | |
| * not containing 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. | |
| */ | |
| function isContract(address account) internal view returns (bool) { | |
| // This method relies in extcodesize, which returns 0 for contracts in | |
| // construction, since the code is only stored at the end of the | |
| // constructor execution. | |
| // According to EIP-1052, 0x0 is the value returned for not-yet created accounts | |
| // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned | |
| // for accounts without code, i.e. `keccak256('')` | |
| bytes32 codehash; | |
| bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470; | |
| // solhint-disable-next-line no-inline-assembly | |
| assembly { codehash := extcodehash(account) } | |
| return (codehash != 0x0 && codehash != accountHash); | |
| } | |
| /** | |
| * @dev Converts an `address` into `address payable`. Note that this is | |
| * simply a type cast: the actual underlying value is not changed. | |
| * | |
| * NOTE: This is a feature of the next version of OpenZeppelin Contracts. | |
| * @dev Get it via `npm install @openzeppelin/contracts@next`. | |
| */ | |
| function toPayable(address account) internal pure returns (address payable) { | |
| return address(uint160(account)); | |
| } | |
| /** | |
| * @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"); | |
| // solhint-disable-next-line avoid-call-value | |
| (bool success, ) = recipient.call.value(amount)(""); | |
| require(success, "Address: unable to send value, recipient may have reverted"); | |
| } | |
| } | |
| /** | |
| * @title Counters | |
| * @author Matt Condon (@shrugs) | |
| * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number | |
| * of elements in a mapping, issuing ERC721 ids, or counting request ids. | |
| * | |
| * Include with `using Counters for Counters.Counter;` | |
| * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the {SafeMath} | |
| * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never | |
| * directly accessed. | |
| */ | |
| library Counters { | |
| using SafeMath for uint256; | |
| struct Counter { | |
| // This variable should never be directly accessed by users of the library: interactions must be restricted to | |
| // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add | |
| // this feature: see https://github.com/ethereum/solidity/issues/4637 | |
| uint256 _value; // default: 0 | |
| } | |
| function current(Counter storage counter) internal view returns (uint256) { | |
| return counter._value; | |
| } | |
| function increment(Counter storage counter) internal { | |
| // The {SafeMath} overflow check can be skipped here, see the comment at the top | |
| counter._value += 1; | |
| } | |
| function decrement(Counter storage counter) internal { | |
| counter._value = counter._value.sub(1); | |
| } | |
| } |
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