// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v5.0.0) (access/extensions/AccessControlEnumerable.sol) pragma solidity ^0.8.20; import {IAccessControlEnumerable} from "./IAccessControlEnumerable.sol"; import {AccessControl} from "../AccessControl.sol"; import {EnumerableSet} from "../../utils/structs/EnumerableSet.sol"; /** * @dev Extension of {AccessControl} that allows enumerating the members of each role. */ abstract contract AccessControlEnumerable is IAccessControlEnumerable, AccessControl { using EnumerableSet for EnumerableSet.AddressSet; mapping(bytes32 role => EnumerableSet.AddressSet) private _roleMembers; /** * @dev See {IERC165-supportsInterface}. */ function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) { return interfaceId == type(IAccessControlEnumerable).interfaceId || super.supportsInterface(interfaceId); } /** * @dev Returns one of the accounts that have `role`. `index` must be a * value between 0 and {getRoleMemberCount}, non-inclusive. * * Role bearers are not sorted in any particular way, and their ordering may * change at any point. * * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure * you perform all queries on the same block. See the following * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post] * for more information. */ function getRoleMember(bytes32 role, uint256 index) public view virtual returns (address) { return _roleMembers[role].at(index); } /** * @dev Returns the number of accounts that have `role`. Can be used * together with {getRoleMember} to enumerate all bearers of a role. */ function getRoleMemberCount(bytes32 role) public view virtual returns (uint256) { return _roleMembers[role].length(); } /** * @dev Return all accounts that have `role` * * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that * this function has an unbounded cost, and using it as part of a state-changing function may render the function * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block. */ function getRoleMembers(bytes32 role) public view virtual returns (address[] memory) { return _roleMembers[role].values(); } /** * @dev Overload {AccessControl-_grantRole} to track enumerable memberships */ function _grantRole(bytes32 role, address account) internal virtual override returns (bool) { bool granted = super._grantRole(role, account); if (granted) { _roleMembers[role].add(account); } return granted; } /** * @dev Overload {AccessControl-_revokeRole} to track enumerable memberships */ function _revokeRole(bytes32 role, address account) internal virtual override returns (bool) { bool revoked = super._revokeRole(role, account); if (revoked) { _roleMembers[role].remove(account); } return revoked; } }