// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v5.0.0) (utils/Nonces.sol) pragma solidity ^0.8.20; import {Initializable} from "../proxy/utils/Initializable.sol"; /** * @dev Provides tracking nonces for addresses. Nonces will only increment. */ abstract contract NoncesUpgradeable is Initializable { /** * @dev The nonce used for an `account` is not the expected current nonce. */ error InvalidAccountNonce(address account, uint256 currentNonce); /// @custom:storage-location erc7201:openzeppelin.storage.Nonces struct NoncesStorage { mapping(address account => uint256) _nonces; } // keccak256(abi.encode(uint256(keccak256("openzeppelin.storage.Nonces")) - 1)) & ~bytes32(uint256(0xff)) bytes32 private constant NoncesStorageLocation = 0x5ab42ced628888259c08ac98db1eb0cf702fc1501344311d8b100cd1bfe4bb00; function _getNoncesStorage() private pure returns (NoncesStorage storage $) { assembly { $.slot := NoncesStorageLocation } } function __Nonces_init() internal onlyInitializing { } function __Nonces_init_unchained() internal onlyInitializing { } /** * @dev Returns the next unused nonce for an address. */ function nonces(address owner) public view virtual returns (uint256) { NoncesStorage storage $ = _getNoncesStorage(); return $._nonces[owner]; } /** * @dev Consumes a nonce. * * Returns the current value and increments nonce. */ function _useNonce(address owner) internal virtual returns (uint256) { NoncesStorage storage $ = _getNoncesStorage(); // For each account, the nonce has an initial value of 0, can only be incremented by one, and cannot be // decremented or reset. This guarantees that the nonce never overflows. unchecked { // It is important to do x++ and not ++x here. return $._nonces[owner]++; } } /** * @dev Same as {_useNonce} but checking that `nonce` is the next valid for `owner`. */ function _useCheckedNonce(address owner, uint256 nonce) internal virtual { uint256 current = _useNonce(owner); if (nonce != current) { revert InvalidAccountNonce(owner, current); } } }