Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;
import {FixedPointMathLib} from "solmate/utils/FixedPointMathLib.sol";
/// @title GOO (Gradual Ownership Optimization) Issuance
/// @author transmissions11 <[email protected]>
/// @author FrankieIsLost <[email protected]>
/// @notice Implementation of the GOO Issuance mechanism.
library LibGOO {
using FixedPointMathLib for uint256;
/// @notice Compute goo balance based on emission multiple, last balance, and time elapsed.
/// @param emissionMultiple The multiple on emissions to consider when computing the balance.
/// @param lastBalanceWad The last checkpointed balance to apply the emission multiple over time to, scaled by 1e18.
/// @param timeElapsedWad The time elapsed since the last checkpoint, scaled by 1e18.
function computeGOOBalance(
uint256 emissionMultiple,
uint256 lastBalanceWad,
uint256 timeElapsedWad
) internal pure returns (uint256) {
unchecked {
// We use wad math here because timeElapsedWad is, as the name indicates, a wad.
uint256 timeElapsedSquaredWad = timeElapsedWad.mulWadDown(timeElapsedWad);
// prettier-ignore
return lastBalanceWad + // The last recorded balance.
// Don't need to do wad multiplication since we're
// multiplying by a plain integer with no decimals.
// Shift right by 2 is equivalent to division by 4.
((emissionMultiple * timeElapsedSquaredWad) >> 2) +
timeElapsedWad.mulWadDown( // Terms are wads, so must mulWad.
// No wad multiplication for emissionMultiple * lastBalance
// because emissionMultiple is a plain integer with no decimals.
// We multiply the sqrt's radicand by 1e18 because it expects ints.
(emissionMultiple * lastBalanceWad * 1e18).sqrt()
);
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
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 Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/
function _checkOwner() internal view virtual {
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 (last updated v4.7.0) (token/ERC721/ERC721.sol)
pragma solidity ^0.8.0;
import "./IERC721.sol";
import "./IERC721Receiver.sol";
import "./extensions/IERC721Metadata.sol";
import "../../utils/Address.sol";
import "../../utils/Context.sol";
import "../../utils/Strings.sol";
import "../../utils/introspection/ERC165.sol";
/**
* @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
* the Metadata extension, but not including the Enumerable extension, which is available separately as
* {ERC721Enumerable}.
*/
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
using Address for address;
using Strings for uint256;
// Token name
string private _name;
// Token symbol
string private _symbol;
// Mapping from token ID to owner address
mapping(uint256 => address) private _owners;
// Mapping owner address to token count
mapping(address => uint256) private _balances;
// 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 Initializes the contract by setting a `name` and a `symbol` to the token collection.
*/
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @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 ||
super.supportsInterface(interfaceId);
}
/**
* @dev See {IERC721-balanceOf}.
*/
function balanceOf(address owner) public view virtual override returns (uint256) {
require(owner != address(0), "ERC721: address zero is not a valid owner");
return _balances[owner];
}
/**
* @dev See {IERC721-ownerOf}.
*/
function ownerOf(uint256 tokenId) public view virtual override returns (address) {
address owner = _owners[tokenId];
require(owner != address(0), "ERC721: invalid token ID");
return owner;
}
/**
* @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) {
_requireMinted(tokenId);
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 overridden in child contracts.
*/
function _baseURI() internal view virtual returns (string memory) {
return "";
}
/**
* @dev See {IERC721-approve}.
*/
function approve(address to, uint256 tokenId) public virtual override {
address owner = ERC721.ownerOf(tokenId);
require(to != owner, "ERC721: approval to current owner");
require(
_msgSender() == owner || isApprovedForAll(owner, _msgSender()),
"ERC721: approve caller is not token owner or approved for all"
);
_approve(to, tokenId);
}
/**
* @dev See {IERC721-getApproved}.
*/
function getApproved(uint256 tokenId) public view virtual override returns (address) {
_requireMinted(tokenId);
return _tokenApprovals[tokenId];
}
/**
* @dev See {IERC721-setApprovalForAll}.
*/
function setApprovalForAll(address operator, bool approved) public virtual override {
_setApprovalForAll(_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 virtual override {
//solhint-disable-next-line max-line-length
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: caller is not token owner or approved");
_transfer(from, to, tokenId);
}
/**
* @dev See {IERC721-safeTransferFrom}.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) public virtual override {
safeTransferFrom(from, to, tokenId, "");
}
/**
* @dev See {IERC721-safeTransferFrom}.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId,
bytes memory data
) public virtual override {
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: caller is not token owner or approved");
_safeTransfer(from, to, tokenId, data);
}
/**
* @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.
*
* `data` is additional data, it has no specified format and it is sent in call to `to`.
*
* This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
* implement alternative mechanisms to perform token transfer, such as signature-based.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function _safeTransfer(
address from,
address to,
uint256 tokenId,
bytes memory data
) internal virtual {
_transfer(from, to, tokenId);
require(_checkOnERC721Received(from, to, tokenId, data), "ERC721: 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`),
* and stop existing when they are burned (`_burn`).
*/
function _exists(uint256 tokenId) internal view virtual returns (bool) {
return _owners[tokenId] != address(0);
}
/**
* @dev Returns whether `spender` is allowed to manage `tokenId`.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
address owner = ERC721.ownerOf(tokenId);
return (spender == owner || isApprovedForAll(owner, spender) || getApproved(tokenId) == spender);
}
/**
* @dev Safely mints `tokenId` and transfers it to `to`.
*
* Requirements:
*
* - `tokenId` must not exist.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function _safeMint(address to, uint256 tokenId) internal virtual {
_safeMint(to, tokenId, "");
}
/**
* @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
* forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
*/
function _safeMint(
address to,
uint256 tokenId,
bytes memory data
) internal virtual {
_mint(to, tokenId);
require(
_checkOnERC721Received(address(0), to, tokenId, data),
"ERC721: transfer to non ERC721Receiver implementer"
);
}
/**
* @dev Mints `tokenId` and transfers it to `to`.
*
* WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
*
* Requirements:
*
* - `tokenId` must not exist.
* - `to` cannot be the zero address.
*
* Emits a {Transfer} event.
*/
function _mint(address to, uint256 tokenId) internal virtual {
require(to != address(0), "ERC721: mint to the zero address");
require(!_exists(tokenId), "ERC721: token already minted");
_beforeTokenTransfer(address(0), to, tokenId);
// Check that tokenId was not minted by `_beforeTokenTransfer` hook
require(!_exists(tokenId), "ERC721: token already minted");
unchecked {
// Will not overflow unless all 2**256 token ids are minted to the same owner.
// Given that tokens are minted one by one, it is impossible in practice that
// this ever happens. Might change if we allow batch minting.
// The ERC fails to describe this case.
_balances[to] += 1;
}
_owners[tokenId] = to;
emit Transfer(address(0), to, tokenId);
_afterTokenTransfer(address(0), to, tokenId);
}
/**
* @dev Destroys `tokenId`.
* The approval is cleared when the token is burned.
* This is an internal function that does not check if the sender is authorized to operate on the token.
*
* Requirements:
*
* - `tokenId` must exist.
*
* Emits a {Transfer} event.
*/
function _burn(uint256 tokenId) internal virtual {
address owner = ERC721.ownerOf(tokenId);
_beforeTokenTransfer(owner, address(0), tokenId);
// Update ownership in case tokenId was transferred by `_beforeTokenTransfer` hook
owner = ERC721.ownerOf(tokenId);
// Clear approvals
delete _tokenApprovals[tokenId];
unchecked {
// Cannot overflow, as that would require more tokens to be burned/transferred
// out than the owner initially received through minting and transferring in.
_balances[owner] -= 1;
}
delete _owners[tokenId];
emit Transfer(owner, address(0), tokenId);
_afterTokenTransfer(owner, address(0), tokenId);
}
/**
* @dev Transfers `tokenId` from `from` to `to`.
* As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
*
* 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
) internal virtual {
require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner");
require(to != address(0), "ERC721: transfer to the zero address");
_beforeTokenTransfer(from, to, tokenId);
// Check that tokenId was not transferred by `_beforeTokenTransfer` hook
require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner");
// Clear approvals from the previous owner
delete _tokenApprovals[tokenId];
unchecked {
// `_balances[from]` cannot overflow for the same reason as described in `_burn`:
// `from`'s balance is the number of token held, which is at least one before the current
// transfer.
// `_balances[to]` could overflow in the conditions described in `_mint`. That would require
// all 2**256 token ids to be minted, which in practice is impossible.
_balances[from] -= 1;
_balances[to] += 1;
}
_owners[tokenId] = to;
emit Transfer(from, to, tokenId);
_afterTokenTransfer(from, to, tokenId);
}
/**
* @dev Approve `to` to operate on `tokenId`
*
* Emits an {Approval} event.
*/
function _approve(address to, uint256 tokenId) internal virtual {
_tokenApprovals[tokenId] = to;
emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
}
/**
* @dev Approve `operator` to operate on all of `owner` tokens
*
* Emits an {ApprovalForAll} event.
*/
function _setApprovalForAll(
address owner,
address operator,
bool approved
) internal virtual {
require(owner != operator, "ERC721: approve to caller");
_operatorApprovals[owner][operator] = approved;
emit ApprovalForAll(owner, operator, approved);
}
/**
* @dev Reverts if the `tokenId` has not been minted yet.
*/
function _requireMinted(uint256 tokenId) internal view virtual {
require(_exists(tokenId), "ERC721: invalid token ID");
}
/**
* @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.onERC721Received.selector;
} catch (bytes memory reason) {
if (reason.length == 0) {
revert("ERC721: transfer to non ERC721Receiver implementer");
} else {
/// @solidity memory-safe-assembly
assembly {
revert(add(32, reason), mload(reason))
}
}
}
} else {
return true;
}
}
/**
* @dev Hook that is called before any token transfer. This includes minting
* and burning.
*
* Calling conditions:
*
* - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
* transferred to `to`.
* - When `from` is zero, `tokenId` will be minted for `to`.
* - When `to` is zero, ``from``'s `tokenId` will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 tokenId
) internal virtual {}
/**
* @dev Hook that is called after any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _afterTokenTransfer(
address from,
address to,
uint256 tokenId
) internal virtual {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC721/IERC721.sol)
pragma solidity ^0.8.0;
import "../../utils/introspection/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`.
*
* 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;
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Transfers `tokenId` token from `from` to `to`.
*
* WARNING: Note that the caller is responsible to confirm that the recipient is capable of receiving ERC721
* or else they may be permanently lost. Usage of {safeTransferFrom} prevents loss, though the caller must
* understand this adds an external call which potentially creates a reentrancy vulnerability.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
*
* Emits a {Transfer} event.
*/
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 Approve or remove `operator` as an operator for the caller.
* Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
*
* Requirements:
*
* - The `operator` cannot be the caller.
*
* Emits an {ApprovalForAll} event.
*/
function setApprovalForAll(address operator, bool _approved) external;
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function getApproved(uint256 tokenId) external view returns (address operator);
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}
*/
function isApprovedForAll(address owner, address operator) external view returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (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 `IERC721Receiver.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/ERC721Enumerable.sol)
pragma solidity ^0.8.0;
import "../ERC721.sol";
import "./IERC721Enumerable.sol";
/**
* @dev This implements an optional extension of {ERC721} defined in the EIP that adds
* enumerability of all the token ids in the contract as well as all token ids owned by each
* account.
*/
abstract contract ERC721Enumerable is ERC721, IERC721Enumerable {
// Mapping from owner to list of owned token IDs
mapping(address => mapping(uint256 => 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;
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC721) returns (bool) {
return interfaceId == type(IERC721Enumerable).interfaceId || super.supportsInterface(interfaceId);
}
/**
* @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
*/
function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256) {
require(index < ERC721.balanceOf(owner), "ERC721Enumerable: owner index out of bounds");
return _ownedTokens[owner][index];
}
/**
* @dev See {IERC721Enumerable-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _allTokens.length;
}
/**
* @dev See {IERC721Enumerable-tokenByIndex}.
*/
function tokenByIndex(uint256 index) public view virtual override returns (uint256) {
require(index < ERC721Enumerable.totalSupply(), "ERC721Enumerable: global index out of bounds");
return _allTokens[index];
}
/**
* @dev Hook that is called before any token transfer. This includes minting
* and burning.
*
* Calling conditions:
*
* - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
* transferred to `to`.
* - When `from` is zero, `tokenId` will be minted for `to`.
* - When `to` is zero, ``from``'s `tokenId` will be burned.
* - `from` and 'to' cannot be the zero address at the same time.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 tokenId
) internal virtual override {
super._beforeTokenTransfer(from, to, tokenId);
if (from == address(0)) {
_addTokenToAllTokensEnumeration(tokenId);
} else if (from != to) {
_removeTokenFromOwnerEnumeration(from, tokenId);
}
if (to == address(0)) {
_removeTokenFromAllTokensEnumeration(tokenId);
} else if (to != from) {
_addTokenToOwnerEnumeration(to, tokenId);
}
}
/**
* @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 {
uint256 length = ERC721.balanceOf(to);
_ownedTokens[to][length] = tokenId;
_ownedTokensIndex[tokenId] = length;
}
/**
* @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 = ERC721.balanceOf(from) - 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
delete _ownedTokensIndex[tokenId];
delete _ownedTokens[from][lastTokenIndex];
}
/**
* @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 - 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
delete _allTokensIndex[tokenId];
_allTokens.pop();
}
}
// 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 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 v4.7.0) (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 functionCallWithValue(target, data, 0, "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");
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResultFromTarget(target, 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) {
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResultFromTarget(target, 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) {
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
* the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
*
* _Available since v4.8._
*/
function verifyCallResultFromTarget(
address target,
bool success,
bytes memory returndata,
string memory errorMessage
) internal view returns (bytes memory) {
if (success) {
if (returndata.length == 0) {
// only check isContract if the call was successful and the return data is empty
// otherwise we already know that it was a contract
require(isContract(target), "Address: call to non-contract");
}
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
/**
* @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason or 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 {
_revert(returndata, errorMessage);
}
}
function _revert(bytes memory returndata, string memory errorMessage) private pure {
// 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
/// @solidity memory-safe-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 (last updated v4.7.0) (utils/Strings.sol)
pragma solidity ^0.8.0;
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant _SYMBOLS = "0123456789abcdef";
uint8 private constant _ADDRESS_LENGTH = 20;
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/
function toString(uint256 value) internal pure returns (string memory) {
unchecked {
uint256 length = 1;
// compute log10(value), and add it to length
uint256 valueCopy = value;
if (valueCopy >= 10**64) {
valueCopy /= 10**64;
length += 64;
}
if (valueCopy >= 10**32) {
valueCopy /= 10**32;
length += 32;
}
if (valueCopy >= 10**16) {
valueCopy /= 10**16;
length += 16;
}
if (valueCopy >= 10**8) {
valueCopy /= 10**8;
length += 8;
}
if (valueCopy >= 10**4) {
valueCopy /= 10**4;
length += 4;
}
if (valueCopy >= 10**2) {
valueCopy /= 10**2;
length += 2;
}
if (valueCopy >= 10**1) {
length += 1;
}
// now, length is log10(value) + 1
string memory buffer = new string(length);
uint256 ptr;
/// @solidity memory-safe-assembly
assembly {
ptr := add(buffer, add(32, length))
}
while (true) {
ptr--;
/// @solidity memory-safe-assembly
assembly {
mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
}
value /= 10;
if (value == 0) break;
}
return buffer;
}
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/
function toHexString(uint256 value) internal pure returns (string memory) {
unchecked {
uint256 length = 1;
// compute log256(value), and add it to length
uint256 valueCopy = value;
if (valueCopy >= 1 << 128) {
valueCopy >>= 128;
length += 16;
}
if (valueCopy >= 1 << 64) {
valueCopy >>= 64;
length += 8;
}
if (valueCopy >= 1 << 32) {
valueCopy >>= 32;
length += 4;
}
if (valueCopy >= 1 << 16) {
valueCopy >>= 16;
length += 2;
}
if (valueCopy >= 1 << 8) {
valueCopy >>= 8;
length += 1;
}
// now, length is log256(value) + 1
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] = _SYMBOLS[value & 0xf];
value >>= 4;
}
require(value == 0, "Strings: hex length insufficient");
return string(buffer);
}
/**
* @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
*/
function toHexString(address addr) internal pure returns (string memory) {
return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
}
}
// 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 (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: AGPL-3.0-only
pragma solidity >=0.8.0;
/// @notice Arithmetic library with operations for fixed-point numbers.
/// @author Solmate (https://github.com/transmissions11/solmate/blob/main/src/utils/FixedPointMathLib.sol)
/// @author Inspired by USM (https://github.com/usmfum/USM/blob/master/contracts/WadMath.sol)
library FixedPointMathLib {
/*//////////////////////////////////////////////////////////////
SIMPLIFIED FIXED POINT OPERATIONS
//////////////////////////////////////////////////////////////*/
uint256 internal constant MAX_UINT256 = 2**256 - 1;
uint256 internal constant WAD = 1e18; // The scalar of ETH and most ERC20s.
function mulWadDown(uint256 x, uint256 y) internal pure returns (uint256) {
return mulDivDown(x, y, WAD); // Equivalent to (x * y) / WAD rounded down.
}
function mulWadUp(uint256 x, uint256 y) internal pure returns (uint256) {
return mulDivUp(x, y, WAD); // Equivalent to (x * y) / WAD rounded up.
}
function divWadDown(uint256 x, uint256 y) internal pure returns (uint256) {
return mulDivDown(x, WAD, y); // Equivalent to (x * WAD) / y rounded down.
}
function divWadUp(uint256 x, uint256 y) internal pure returns (uint256) {
return mulDivUp(x, WAD, y); // Equivalent to (x * WAD) / y rounded up.
}
/*//////////////////////////////////////////////////////////////
LOW LEVEL FIXED POINT OPERATIONS
//////////////////////////////////////////////////////////////*/
function mulDivDown(
uint256 x,
uint256 y,
uint256 denominator
) internal pure returns (uint256 z) {
/// @solidity memory-safe-assembly
assembly {
// Equivalent to require(denominator != 0 && (y == 0 || x <= type(uint256).max / y))
if iszero(mul(denominator, iszero(mul(y, gt(x, div(MAX_UINT256, y)))))) {
revert(0, 0)
}
// Divide x * y by the denominator.
z := div(mul(x, y), denominator)
}
}
function mulDivUp(
uint256 x,
uint256 y,
uint256 denominator
) internal pure returns (uint256 z) {
/// @solidity memory-safe-assembly
assembly {
// Equivalent to require(denominator != 0 && (y == 0 || x <= type(uint256).max / y))
if iszero(mul(denominator, iszero(mul(y, gt(x, div(MAX_UINT256, y)))))) {
revert(0, 0)
}
// If x * y modulo the denominator is strictly greater than 0,
// 1 is added to round up the division of x * y by the denominator.
z := add(gt(mod(mul(x, y), denominator), 0), div(mul(x, y), denominator))
}
}
function rpow(
uint256 x,
uint256 n,
uint256 scalar
) internal pure returns (uint256 z) {
/// @solidity memory-safe-assembly
assembly {
switch x
case 0 {
switch n
case 0 {
// 0 ** 0 = 1
z := scalar
}
default {
// 0 ** n = 0
z := 0
}
}
default {
switch mod(n, 2)
case 0 {
// If n is even, store scalar in z for now.
z := scalar
}
default {
// If n is odd, store x in z for now.
z := x
}
// Shifting right by 1 is like dividing by 2.
let half := shr(1, scalar)
for {
// Shift n right by 1 before looping to halve it.
n := shr(1, n)
} n {
// Shift n right by 1 each iteration to halve it.
n := shr(1, n)
} {
// Revert immediately if x ** 2 would overflow.
// Equivalent to iszero(eq(div(xx, x), x)) here.
if shr(128, x) {
revert(0, 0)
}
// Store x squared.
let xx := mul(x, x)
// Round to the nearest number.
let xxRound := add(xx, half)
// Revert if xx + half overflowed.
if lt(xxRound, xx) {
revert(0, 0)
}
// Set x to scaled xxRound.
x := div(xxRound, scalar)
// If n is even:
if mod(n, 2) {
// Compute z * x.
let zx := mul(z, x)
// If z * x overflowed:
if iszero(eq(div(zx, x), z)) {
// Revert if x is non-zero.
if iszero(iszero(x)) {
revert(0, 0)
}
}
// Round to the nearest number.
let zxRound := add(zx, half)
// Revert if zx + half overflowed.
if lt(zxRound, zx) {
revert(0, 0)
}
// Return properly scaled zxRound.
z := div(zxRound, scalar)
}
}
}
}
}
/*//////////////////////////////////////////////////////////////
GENERAL NUMBER UTILITIES
//////////////////////////////////////////////////////////////*/
function sqrt(uint256 x) internal pure returns (uint256 z) {
/// @solidity memory-safe-assembly
assembly {
let y := x // We start y at x, which will help us make our initial estimate.
z := 181 // The "correct" value is 1, but this saves a multiplication later.
// This segment is to get a reasonable initial estimate for the Babylonian method. With a bad
// start, the correct # of bits increases ~linearly each iteration instead of ~quadratically.
// We check y >= 2^(k + 8) but shift right by k bits
// each branch to ensure that if x >= 256, then y >= 256.
if iszero(lt(y, 0x10000000000000000000000000000000000)) {
y := shr(128, y)
z := shl(64, z)
}
if iszero(lt(y, 0x1000000000000000000)) {
y := shr(64, y)
z := shl(32, z)
}
if iszero(lt(y, 0x10000000000)) {
y := shr(32, y)
z := shl(16, z)
}
if iszero(lt(y, 0x1000000)) {
y := shr(16, y)
z := shl(8, z)
}
// Goal was to get z*z*y within a small factor of x. More iterations could
// get y in a tighter range. Currently, we will have y in [256, 256*2^16).
// We ensured y >= 256 so that the relative difference between y and y+1 is small.
// That's not possible if x < 256 but we can just verify those cases exhaustively.
// Now, z*z*y <= x < z*z*(y+1), and y <= 2^(16+8), and either y >= 256, or x < 256.
// Correctness can be checked exhaustively for x < 256, so we assume y >= 256.
// Then z*sqrt(y) is within sqrt(257)/sqrt(256) of sqrt(x), or about 20bps.
// For s in the range [1/256, 256], the estimate f(s) = (181/1024) * (s+1) is in the range
// (1/2.84 * sqrt(s), 2.84 * sqrt(s)), with largest error when s = 1 and when s = 256 or 1/256.
// Since y is in [256, 256*2^16), let a = y/65536, so that a is in [1/256, 256). Then we can estimate
// sqrt(y) using sqrt(65536) * 181/1024 * (a + 1) = 181/4 * (y + 65536)/65536 = 181 * (y + 65536)/2^18.
// There is no overflow risk here since y < 2^136 after the first branch above.
z := shr(18, mul(z, add(y, 65536))) // A mul() is saved from starting z at 181.
// Given the worst case multiplicative error of 2.84 above, 7 iterations should be enough.
z := shr(1, add(z, div(x, z)))
z := shr(1, add(z, div(x, z)))
z := shr(1, add(z, div(x, z)))
z := shr(1, add(z, div(x, z)))
z := shr(1, add(z, div(x, z)))
z := shr(1, add(z, div(x, z)))
z := shr(1, add(z, div(x, z)))
// If x+1 is a perfect square, the Babylonian method cycles between
// floor(sqrt(x)) and ceil(sqrt(x)). This statement ensures we return floor.
// See: https://en.wikipedia.org/wiki/Integer_square_root#Using_only_integer_division
// Since the ceil is rare, we save gas on the assignment and repeat division in the rare case.
// If you don't care whether the floor or ceil square root is returned, you can remove this statement.
z := sub(z, lt(div(x, z), z))
}
}
function unsafeMod(uint256 x, uint256 y) internal pure returns (uint256 z) {
/// @solidity memory-safe-assembly
assembly {
// Mod x by y. Note this will return
// 0 instead of reverting if y is zero.
z := mod(x, y)
}
}
function unsafeDiv(uint256 x, uint256 y) internal pure returns (uint256 r) {
/// @solidity memory-safe-assembly
assembly {
// Divide x by y. Note this will return
// 0 instead of reverting if y is zero.
r := div(x, y)
}
}
function unsafeDivUp(uint256 x, uint256 y) internal pure returns (uint256 z) {
/// @solidity memory-safe-assembly
assembly {
// Add 1 to x * y if x % y > 0. Note this will
// return 0 instead of reverting if y is zero.
z := add(gt(mod(x, y), 0), div(x, y))
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;
/// @notice Signed 18 decimal fixed point (wad) arithmetic library.
/// @author Solmate (https://github.com/transmissions11/solmate/blob/main/src/utils/SignedWadMath.sol)
/// @author Modified from Remco Bloemen (https://xn--2-umb.com/22/exp-ln/index.html)
/// @dev Will not revert on overflow, only use where overflow is not possible.
function toWadUnsafe(uint256 x) pure returns (int256 r) {
/// @solidity memory-safe-assembly
assembly {
// Multiply x by 1e18.
r := mul(x, 1000000000000000000)
}
}
/// @dev Takes an integer amount of seconds and converts it to a wad amount of days.
/// @dev Will not revert on overflow, only use where overflow is not possible.
/// @dev Not meant for negative second amounts, it assumes x is positive.
function toDaysWadUnsafe(uint256 x) pure returns (int256 r) {
/// @solidity memory-safe-assembly
assembly {
// Multiply x by 1e18 and then divide it by 86400.
r := div(mul(x, 1000000000000000000), 86400)
}
}
/// @dev Takes a wad amount of days and converts it to an integer amount of seconds.
/// @dev Will not revert on overflow, only use where overflow is not possible.
/// @dev Not meant for negative day amounts, it assumes x is positive.
function fromDaysWadUnsafe(int256 x) pure returns (uint256 r) {
/// @solidity memory-safe-assembly
assembly {
// Multiply x by 86400 and then divide it by 1e18.
r := div(mul(x, 86400), 1000000000000000000)
}
}
/// @dev Will not revert on overflow, only use where overflow is not possible.
function unsafeWadMul(int256 x, int256 y) pure returns (int256 r) {
/// @solidity memory-safe-assembly
assembly {
// Multiply x by y and divide by 1e18.
r := sdiv(mul(x, y), 1000000000000000000)
}
}
/// @dev Will return 0 instead of reverting if y is zero and will
/// not revert on overflow, only use where overflow is not possible.
function unsafeWadDiv(int256 x, int256 y) pure returns (int256 r) {
/// @solidity memory-safe-assembly
assembly {
// Multiply x by 1e18 and divide it by y.
r := sdiv(mul(x, 1000000000000000000), y)
}
}
function wadMul(int256 x, int256 y) pure returns (int256 r) {
/// @solidity memory-safe-assembly
assembly {
// Store x * y in r for now.
r := mul(x, y)
// Equivalent to require(x == 0 || (x * y) / x == y)
if iszero(or(iszero(x), eq(sdiv(r, x), y))) {
revert(0, 0)
}
// Scale the result down by 1e18.
r := sdiv(r, 1000000000000000000)
}
}
function wadDiv(int256 x, int256 y) pure returns (int256 r) {
/// @solidity memory-safe-assembly
assembly {
// Store x * 1e18 in r for now.
r := mul(x, 1000000000000000000)
// Equivalent to require(y != 0 && ((x * 1e18) / 1e18 == x))
if iszero(and(iszero(iszero(y)), eq(sdiv(r, 1000000000000000000), x))) {
revert(0, 0)
}
// Divide r by y.
r := sdiv(r, y)
}
}
function wadExp(int256 x) pure returns (int256 r) {
unchecked {
// When the result is < 0.5 we return zero. This happens when
// x <= floor(log(0.5e18) * 1e18) ~ -42e18
if (x <= -42139678854452767551) return 0;
// When the result is > (2**255 - 1) / 1e18 we can not represent it as an
// int. This happens when x >= floor(log((2**255 - 1) / 1e18) * 1e18) ~ 135.
if (x >= 135305999368893231589) revert("EXP_OVERFLOW");
// x is now in the range (-42, 136) * 1e18. Convert to (-42, 136) * 2**96
// for more intermediate precision and a binary basis. This base conversion
// is a multiplication by 1e18 / 2**96 = 5**18 / 2**78.
x = (x << 78) / 5**18;
// Reduce range of x to (-½ ln 2, ½ ln 2) * 2**96 by factoring out powers
// of two such that exp(x) = exp(x') * 2**k, where k is an integer.
// Solving this gives k = round(x / log(2)) and x' = x - k * log(2).
int256 k = ((x << 96) / 54916777467707473351141471128 + 2**95) >> 96;
x = x - k * 54916777467707473351141471128;
// k is in the range [-61, 195].
// Evaluate using a (6, 7)-term rational approximation.
// p is made monic, we'll multiply by a scale factor later.
int256 y = x + 1346386616545796478920950773328;
y = ((y * x) >> 96) + 57155421227552351082224309758442;
int256 p = y + x - 94201549194550492254356042504812;
p = ((p * y) >> 96) + 28719021644029726153956944680412240;
p = p * x + (4385272521454847904659076985693276 << 96);
// We leave p in 2**192 basis so we don't need to scale it back up for the division.
int256 q = x - 2855989394907223263936484059900;
q = ((q * x) >> 96) + 50020603652535783019961831881945;
q = ((q * x) >> 96) - 533845033583426703283633433725380;
q = ((q * x) >> 96) + 3604857256930695427073651918091429;
q = ((q * x) >> 96) - 14423608567350463180887372962807573;
q = ((q * x) >> 96) + 26449188498355588339934803723976023;
/// @solidity memory-safe-assembly
assembly {
// Div in assembly because solidity adds a zero check despite the unchecked.
// The q polynomial won't have zeros in the domain as all its roots are complex.
// No scaling is necessary because p is already 2**96 too large.
r := sdiv(p, q)
}
// r should be in the range (0.09, 0.25) * 2**96.
// We now need to multiply r by:
// * the scale factor s = ~6.031367120.
// * the 2**k factor from the range reduction.
// * the 1e18 / 2**96 factor for base conversion.
// We do this all at once, with an intermediate result in 2**213
// basis, so the final right shift is always by a positive amount.
r = int256((uint256(r) * 3822833074963236453042738258902158003155416615667) >> uint256(195 - k));
}
}
function wadLn(int256 x) pure returns (int256 r) {
unchecked {
require(x > 0, "UNDEFINED");
// We want to convert x from 10**18 fixed point to 2**96 fixed point.
// We do this by multiplying by 2**96 / 10**18. But since
// ln(x * C) = ln(x) + ln(C), we can simply do nothing here
// and add ln(2**96 / 10**18) at the end.
/// @solidity memory-safe-assembly
assembly {
r := shl(7, lt(0xffffffffffffffffffffffffffffffff, x))
r := or(r, shl(6, lt(0xffffffffffffffff, shr(r, x))))
r := or(r, shl(5, lt(0xffffffff, shr(r, x))))
r := or(r, shl(4, lt(0xffff, shr(r, x))))
r := or(r, shl(3, lt(0xff, shr(r, x))))
r := or(r, shl(2, lt(0xf, shr(r, x))))
r := or(r, shl(1, lt(0x3, shr(r, x))))
r := or(r, lt(0x1, shr(r, x)))
}
// Reduce range of x to (1, 2) * 2**96
// ln(2^k * x) = k * ln(2) + ln(x)
int256 k = r - 96;
x <<= uint256(159 - k);
x = int256(uint256(x) >> 159);
// Evaluate using a (8, 8)-term rational approximation.
// p is made monic, we will multiply by a scale factor later.
int256 p = x + 3273285459638523848632254066296;
p = ((p * x) >> 96) + 24828157081833163892658089445524;
p = ((p * x) >> 96) + 43456485725739037958740375743393;
p = ((p * x) >> 96) - 11111509109440967052023855526967;
p = ((p * x) >> 96) - 45023709667254063763336534515857;
p = ((p * x) >> 96) - 14706773417378608786704636184526;
p = p * x - (795164235651350426258249787498 << 96);
// We leave p in 2**192 basis so we don't need to scale it back up for the division.
// q is monic by convention.
int256 q = x + 5573035233440673466300451813936;
q = ((q * x) >> 96) + 71694874799317883764090561454958;
q = ((q * x) >> 96) + 283447036172924575727196451306956;
q = ((q * x) >> 96) + 401686690394027663651624208769553;
q = ((q * x) >> 96) + 204048457590392012362485061816622;
q = ((q * x) >> 96) + 31853899698501571402653359427138;
q = ((q * x) >> 96) + 909429971244387300277376558375;
/// @solidity memory-safe-assembly
assembly {
// Div in assembly because solidity adds a zero check despite the unchecked.
// The q polynomial is known not to have zeros in the domain.
// No scaling required because p is already 2**96 too large.
r := sdiv(p, q)
}
// r is in the range (0, 0.125) * 2**96
// Finalization, we need to:
// * multiply by the scale factor s = 5.549…
// * add ln(2**96 / 10**18)
// * add k * ln(2)
// * multiply by 10**18 / 2**96 = 5**18 >> 78
// mul s * 5e18 * 2**96, base is now 5**18 * 2**192
r *= 1677202110996718588342820967067443963516166;
// add ln(2) * k * 5e18 * 2**192
r += 16597577552685614221487285958193947469193820559219878177908093499208371 * k;
// add ln(2**96 / 10**18) * 5e18 * 2**192
r += 600920179829731861736702779321621459595472258049074101567377883020018308;
// base conversion: mul 2**18 / 2**192
r >>= 174;
}
}
/// @dev Will return 0 instead of reverting if y is zero.
function unsafeDiv(int256 x, int256 y) pure returns (int256 r) {
/// @solidity memory-safe-assembly
assembly {
// Divide x by y.
r := sdiv(x, y)
}
}
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.13;
import {IERC721, ERC721, ERC721Enumerable} from "@openzeppelin/token/ERC721/extensions/ERC721Enumerable.sol";
import {Ownable} from "@openzeppelin/access/Ownable.sol";
import {toWadUnsafe, toDaysWadUnsafe} from "solmate/utils/SignedWadMath.sol";
import {LibGOO} from "goo-issuance/LibGOO.sol";
/// @dev An enum for representing whether to
/// increase or decrease a user's goo balance.
enum GooBalanceUpdateType {
INCREASE,
DECREASE
}
/// @notice Struct holding data relevant to each user's account.
struct UserData {
// User's goo balance at time of last checkpointing.
uint128 lastBalance;
// Timestamp of the last goo balance checkpoint.
uint64 lastTimestamp;
}
contract OwnedEnumerableNFT is ERC721Enumerable, Ownable {
constructor(string memory name, string memory symbol) ERC721(name, symbol) Ownable() {}
function mint(address recipient) public virtual onlyOwner returns (uint256 id) {
id = totalSupply();
_safeMint(recipient, id);
}
function burn(uint256 id) public onlyOwner {
_burn(id);
}
}
// SPY NFT will produce Goo
contract SpyNFT is OwnedEnumerableNFT {
/*//////////////////////////////////////////////////////////////
Variables
//////////////////////////////////////////////////////////////*/
/// Random emission multiple to massage the curve into place
uint256 public constant EMISSION_MULTIPLE = 69;
/// Keeps track of virtual GOO Balance
mapping(address => UserData) public getUserData;
/*//////////////////////////////////////////////////////////////
Events
//////////////////////////////////////////////////////////////*/
event GooBalanceUpdated(address indexed user, uint256 newGooBalance);
/*//////////////////////////////////////////////////////////////
Errors
//////////////////////////////////////////////////////////////*/
error TooEarly();
/*//////////////////////////////////////////////////////////////
Constructor
//////////////////////////////////////////////////////////////*/
constructor() OwnedEnumerableNFT("Spy", "SPIES") {}
/*//////////////////////////////////////////////////////////////
Goo Functionality (Read only)
//////////////////////////////////////////////////////////////*/
/// @notice Calculate a user's virtual goo balance.
/// @param user The user to query balance for.
function gooBalance(address user) public view returns (uint256) {
// Compute the user's virtual goo balance using LibGOO.
// prettier-ignore
return LibGOO.computeGOOBalance(
EMISSION_MULTIPLE * balanceOf(user),
getUserData[user].lastBalance,
uint256(toDaysWadUnsafe(block.timestamp - getUserData[user].lastTimestamp))
);
}
/*//////////////////////////////////////////////////////////////
Goo Functionality (Permissioned)
//////////////////////////////////////////////////////////////*/
/// @notice Update a user's virtual goo balance.
/// @param user The user whose virtual goo balance we should update.
/// @param gooAmount The amount of goo to update the user's virtual balance by.
/// @param updateType Whether to increase or decrease the user's balance by gooAmount.
function updateUserGooBalance(address user, uint256 gooAmount, GooBalanceUpdateType updateType) public onlyOwner {
// Will revert due to underflow if we're decreasing by more than the user's current balance.
// Don't need to do checked addition in the increase case, but we do it anyway for convenience.
uint256 updatedBalance =
updateType == GooBalanceUpdateType.INCREASE ? gooBalance(user) + gooAmount : gooBalance(user) - gooAmount;
// Snapshot the user's new goo balance with the current timestamp.
getUserData[user].lastBalance = uint128(updatedBalance);
getUserData[user].lastTimestamp = uint64(block.timestamp);
emit GooBalanceUpdated(user, updatedBalance);
}
/// @notice Superuser transferFrom
function sudoTransferFrom(address from, address to, uint256 tokenId) public onlyOwner {
// if (getUserData[from].lastTimestamp == 0) {
// getUserData[from].lastTimestamp = uint64(block.timestamp);
// }
// if (getUserData[to].lastTimestamp == 0) {
// getUserData[to].lastTimestamp = uint64(block.timestamp);
// }
unchecked {
// We update their last balance before updating their emission multiple to avoid
// penalizing them by retroactively applying their new (lower) balanceOf
getUserData[from].lastBalance = uint128(gooBalance(from));
getUserData[from].lastTimestamp = uint64(block.timestamp);
// We update their last balance before updating their emission multiple to avoid
// overpaying them by retroactively applying their new (higher) balanceOf
getUserData[to].lastBalance = uint128(gooBalance(to));
getUserData[to].lastTimestamp = uint64(block.timestamp);
}
// State changes happen *after* gooBalance is update
_transfer(from, to, tokenId);
}
/*//////////////////////////////////////////////////////////////
ERC721 Functionality
//////////////////////////////////////////////////////////////*/
function mint(address recipient, uint256 timestamp) public onlyOwner returns (uint256 id) {
// Prevent bugs
if (timestamp < block.timestamp) {
revert TooEarly();
}
// If we can't get the gooBalance, then minting hasn't start yet
// If we can get the gooBal then we good
try this.gooBalance(recipient) returns (uint256 existingGooBal) {
getUserData[recipient].lastBalance = uint128(existingGooBal);
} catch {}
getUserData[recipient].lastTimestamp = uint64(timestamp);
id = totalSupply();
_safeMint(recipient, id);
}
function transferFrom(address from, address to, uint256 tokenId) public override (ERC721, IERC721) {
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
if (getUserData[from].lastTimestamp == 0) {
getUserData[from].lastTimestamp = uint64(block.timestamp);
}
if (getUserData[to].lastTimestamp == 0) {
getUserData[to].lastTimestamp = uint64(block.timestamp);
}
unchecked {
// We update their last balance before updating their emission multiple to avoid
// penalizing them by retroactively applying their new (lower) balanceOf
getUserData[from].lastBalance = uint128(gooBalance(from));
getUserData[from].lastTimestamp = uint64(block.timestamp);
// We update their last balance before updating their emission multiple to avoid
// overpaying them by retroactively applying their new (higher) balanceOf
getUserData[to].lastBalance = uint128(gooBalance(to));
getUserData[to].lastTimestamp = uint64(block.timestamp);
}
// State changes happen *after* gooBalance is update
_transfer(from, to, tokenId);
}
function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data)
public
override (ERC721, IERC721)
{
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: caller is not token owner or approved");
unchecked {
// We update their last balance before updating their emission multiple to avoid
// penalizing them by retroactively applying their new (lower) balanceOf
getUserData[from].lastBalance = uint128(gooBalance(from));
getUserData[from].lastTimestamp = uint64(block.timestamp);
// We update their last balance before updating their emission multiple to avoid
// overpaying them by retroactively applying their new (higher) balanceOf
getUserData[to].lastBalance = uint128(gooBalance(to));
getUserData[to].lastTimestamp = uint64(block.timestamp);
}
_safeTransfer(from, to, tokenId, data);
}
function tokenURI(uint256 tokenId) public pure override returns (string memory) {
string[4] memory parts;
parts[0] =
'<svg xmlns="http://www.w3.org/2000/svg" preserveAspectRatio="xMinYMin meet" viewBox="0 0 350 350"><style>.base { fill: white; font-family: serif; font-size: 14px; }</style><rect width="100%" height="100%" fill="black" /><text x="10" y="20" class="base">';
parts[1] = "SPY #";
parts[2] = SVGUtils.toString(tokenId);
parts[3] = "</text></svg>";
string memory output = string(abi.encodePacked(parts[0], parts[1], parts[2], parts[3]));
string memory json = Base64.encode(
bytes(
string(
abi.encodePacked(
'{"name": "Spy #',
SVGUtils.toString(tokenId),
'", "description": "A Spy in the Knife Game Universe.", "image": "data:image/svg+xml;base64,',
Base64.encode(bytes(output)),
'"}'
)
)
)
);
output = string(abi.encodePacked("data:application/json;base64,", json));
return output;
}
}
contract KnifeNFT is OwnedEnumerableNFT {
constructor() OwnedEnumerableNFT("Knife", "KNIVES") {}
function sudoTransferFrom(address from, address to, uint256 tokenId) public onlyOwner {
_transfer(from, to, tokenId);
}
function tokenURI(uint256 tokenId) public pure override returns (string memory) {
string[4] memory parts;
parts[0] =
'<svg xmlns="http://www.w3.org/2000/svg" preserveAspectRatio="xMinYMin meet" viewBox="0 0 350 350"><style>.base { fill: white; font-family: serif; font-size: 14px; }</style><rect width="100%" height="100%" fill="black" /><text x="10" y="20" class="base">';
parts[1] = "Knife #";
parts[2] = SVGUtils.toString(tokenId);
parts[3] = "</text></svg>";
string memory output = string(abi.encodePacked(parts[0], parts[1], parts[2], parts[3]));
string memory json = Base64.encode(
bytes(
string(
abi.encodePacked(
'{"name": "Knife #',
SVGUtils.toString(tokenId),
'", "description": "A Knife the Knife Game Universe.", "image": "data:image/svg+xml;base64,',
Base64.encode(bytes(output)),
'"}'
)
)
)
);
output = string(abi.encodePacked("data:application/json;base64,", json));
return output;
}
}
/// [MIT License]
/// @title Base64
/// @notice Provides a function for encoding some bytes in base64
/// @author Brecht Devos <[email protected]>
library Base64 {
bytes internal constant TABLE = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
/// @notice Encodes some bytes to the base64 representation
function encode(bytes memory data) internal pure returns (string memory) {
uint256 len = data.length;
if (len == 0) return "";
// multiply by 4/3 rounded up
uint256 encodedLen = 4 * ((len + 2) / 3);
// Add some extra buffer at the end
bytes memory result = new bytes(encodedLen + 32);
bytes memory table = TABLE;
assembly {
let tablePtr := add(table, 1)
let resultPtr := add(result, 32)
for { let i := 0 } lt(i, len) {} {
i := add(i, 3)
let input := and(mload(add(data, i)), 0xffffff)
let out := mload(add(tablePtr, and(shr(18, input), 0x3F)))
out := shl(8, out)
out := add(out, and(mload(add(tablePtr, and(shr(12, input), 0x3F))), 0xFF))
out := shl(8, out)
out := add(out, and(mload(add(tablePtr, and(shr(6, input), 0x3F))), 0xFF))
out := shl(8, out)
out := add(out, and(mload(add(tablePtr, and(input, 0x3F))), 0xFF))
out := shl(224, out)
mstore(resultPtr, out)
resultPtr := add(resultPtr, 4)
}
switch mod(len, 3)
case 1 { mstore(sub(resultPtr, 2), shl(240, 0x3d3d)) }
case 2 { mstore(sub(resultPtr, 1), shl(248, 0x3d)) }
mstore(result, encodedLen)
}
return string(result);
}
}
library SVGUtils {
function toString(uint256 value) internal pure returns (string memory) {
// Inspired by OraclizeAPI's implementation - MIT license
// 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);
}
}