ParamsControl

一般而言，区块链需要通过硬分叉（hardfork）才能更改区块奖励等全局参数。Conflux引入ParamsControl内置合约，使得DAO能够在链上投票来调整Conflux的链参数，如PoW的每个区块的出块奖励，或PoS链上的利率。ParamsControl内置合约由CIP-94引入，CIP-94 介绍页面进行了一定的介绍。

合约接口

// SPDX-License-Identifier: MIT

pragma solidity >=0.8.0;

interface ParamsControl {
    struct Vote {
        uint16 topic_index;
        uint256[3] votes;
    }

    /*** Query Functions ***/
    /**
     * @dev cast vote for parameters
     * @param vote_round The round to vote for
     * @param vote_data The list of votes to cast
     */
    function castVote(uint64 vote_round, Vote[] calldata vote_data) external;

    /**
     * @dev read the vote data of an account
     * @param addr The address of the account to read
     */
    function readVote(address addr) external view returns (Vote[] memory);

    /**
     * @dev Current vote round
     */
    function currentRound() external view returns (uint64);

    /**
     * @dev read the total votes of given round
     * @param vote_round The vote number
     */
    function totalVotes(uint64 vote_round) external view returns (Vote[] memory);

    /**
     * @dev read the PoS stake for the round.
     */
    function posStakeForVotes(uint64) external view returns (uint256);

    event CastVote(uint64 indexed vote_round, address indexed addr, uint16 indexed topic_index, uint256[3] votes);
    event RevokeVote(uint64 indexed vote_round, address indexed addr, uint16 indexed topic_index, uint256[3] votes);
}