You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
84 lines
3.6 KiB
84 lines
3.6 KiB
// SPDX-License-Identifier: MIT
|
|
// OpenZeppelin Contracts (last updated v5.2.0) (governance/utils/VotesExtended.sol)
|
|
pragma solidity ^0.8.20;
|
|
|
|
import {Checkpoints} from "../../utils/structs/Checkpoints.sol";
|
|
import {Votes} from "./Votes.sol";
|
|
import {SafeCast} from "../../utils/math/SafeCast.sol";
|
|
|
|
/**
|
|
* @dev Extension of {Votes} that adds checkpoints for delegations and balances.
|
|
*
|
|
* WARNING: While this contract extends {Votes}, valid uses of {Votes} may not be compatible with
|
|
* {VotesExtended} without additional considerations. This implementation of {_transferVotingUnits} must
|
|
* run AFTER the voting weight movement is registered, such that it is reflected on {_getVotingUnits}.
|
|
*
|
|
* Said differently, {VotesExtended} MUST be integrated in a way that calls {_transferVotingUnits} AFTER the
|
|
* asset transfer is registered and balances are updated:
|
|
*
|
|
* ```solidity
|
|
* contract VotingToken is Token, VotesExtended {
|
|
* function transfer(address from, address to, uint256 tokenId) public override {
|
|
* super.transfer(from, to, tokenId); // <- Perform the transfer first ...
|
|
* _transferVotingUnits(from, to, 1); // <- ... then call _transferVotingUnits.
|
|
* }
|
|
*
|
|
* function _getVotingUnits(address account) internal view override returns (uint256) {
|
|
* return balanceOf(account);
|
|
* }
|
|
* }
|
|
* ```
|
|
*
|
|
* {ERC20Votes} and {ERC721Votes} follow this pattern and are thus safe to use with {VotesExtended}.
|
|
*/
|
|
abstract contract VotesExtended is Votes {
|
|
using Checkpoints for Checkpoints.Trace160;
|
|
using Checkpoints for Checkpoints.Trace208;
|
|
|
|
mapping(address delegator => Checkpoints.Trace160) private _userDelegationCheckpoints;
|
|
mapping(address account => Checkpoints.Trace208) private _userVotingUnitsCheckpoints;
|
|
|
|
/**
|
|
* @dev Returns the delegate of an `account` at a specific moment in the past. If the `clock()` is
|
|
* configured to use block numbers, this will return the value at the end of the corresponding block.
|
|
*
|
|
* Requirements:
|
|
*
|
|
* - `timepoint` must be in the past. If operating using block numbers, the block must be already mined.
|
|
*/
|
|
function getPastDelegate(address account, uint256 timepoint) public view virtual returns (address) {
|
|
return address(_userDelegationCheckpoints[account].upperLookupRecent(_validateTimepoint(timepoint)));
|
|
}
|
|
|
|
/**
|
|
* @dev Returns the `balanceOf` of an `account` at a specific moment in the past. If the `clock()` is
|
|
* configured to use block numbers, this will return the value at the end of the corresponding block.
|
|
*
|
|
* Requirements:
|
|
*
|
|
* - `timepoint` must be in the past. If operating using block numbers, the block must be already mined.
|
|
*/
|
|
function getPastBalanceOf(address account, uint256 timepoint) public view virtual returns (uint256) {
|
|
return _userVotingUnitsCheckpoints[account].upperLookupRecent(_validateTimepoint(timepoint));
|
|
}
|
|
|
|
/// @inheritdoc Votes
|
|
function _delegate(address account, address delegatee) internal virtual override {
|
|
super._delegate(account, delegatee);
|
|
|
|
_userDelegationCheckpoints[account].push(clock(), uint160(delegatee));
|
|
}
|
|
|
|
/// @inheritdoc Votes
|
|
function _transferVotingUnits(address from, address to, uint256 amount) internal virtual override {
|
|
super._transferVotingUnits(from, to, amount);
|
|
if (from != to) {
|
|
if (from != address(0)) {
|
|
_userVotingUnitsCheckpoints[from].push(clock(), SafeCast.toUint208(_getVotingUnits(from)));
|
|
}
|
|
if (to != address(0)) {
|
|
_userVotingUnitsCheckpoints[to].push(clock(), SafeCast.toUint208(_getVotingUnits(to)));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|