Solidity Openzeppelin VestingWallet合约
前言
VestingWallet合约用于实现对某个用户地址在一段时间内进行发放eth或erc20代币,发放的方式默认为线性释放,支持重写自定义的释放方式。
一、接口
FUNCTIONS
constructor(beneficiaryAddress, startTimestamp, durationSeconds)
receive()
beneficiary()
start()
duration()
released()
released(token)
release()
release(token)
vestedAmount(timestamp)
vestedAmount(token, timestamp)
_vestingSchedule(totalAllocation, timestamp)
EVENTS
EtherReleased(amount)
ERC20Released(token, amount)
二、Openzeppelin实现及注释
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (finance/VestingWallet.sol)
pragma solidity ^0.8.0;
import "../token/ERC20/utils/SafeERC20.sol";
import "../utils/Address.sol";
import "../utils/Context.sol";
/**
* @title VestingWallet
* @dev This contract handles the vesting of Eth and ERC20 tokens for a given beneficiary. Custody of multiple tokens
* can be given to this contract, which will release the token to the beneficiary following a given vesting schedule.
* The vesting schedule is customizable through the {vestedAmount} function.
*
* Any token transferred to this contract will follow the vesting schedule as if they were locked from the beginning.
* Consequently, if the vesting has already started, any amount of tokens sent to this contract will (at least partly)
* be immediately releasable.
*/
contract VestingWallet is Context {
event EtherReleased(uint256 amount);
event ERC20Released(address indexed token, uint256 amount);
uint256 private _released; //已释放的eth数量
mapping(address => uint256) private _erc20Released;//已释放的erc20代币数量
address private immutable _beneficiary;//被发放地址
uint64 private immutable _start;//发放开始时间
uint64 private immutable _duration;//发放时间间隔
/**构建函数时需要传入发放地址,开始时间及发放间隔
* @dev Set the beneficiary, start timestamp and vesting duration of the vesting wallet.
*/
constructor(
address beneficiaryAddress,
uint64 startTimestamp,
uint64 durationSeconds
) payable {
require(beneficiaryAddress != address(0), "VestingWallet: beneficiary is zero address");
_beneficiary = beneficiaryAddress;
_start = startTimestamp;
_duration = durationSeconds;
}
/**
* @dev The contract should be able to receive Eth.
*/
receive() external payable virtual {
}
/**
* @dev Getter for the beneficiary address.
*/
function beneficiary() public view virtual returns (address) {
return _beneficiary;
}
/**
* @dev Getter for the start timestamp.
*/
function start() public view virtual returns (uint256) {
return _start;
}
/**
* @dev Getter for the vesting duration.
*/
function duration() public view virtual returns (uint256) {
return _duration;
}
/**已释放数量
* @dev Amount of eth already released
*/
function released() public view virtual returns (uint256) {
return _released;
}
/**
* @dev Amount of token already released
*/
function released(address token) public view virtual returns (uint256) {
return _erc20Released[token];
}
/**剩余可释放数量
* @dev Getter for the amount of releasable eth.
*/
function releasable() public view virtual returns (uint256) {
return vestedAmount(uint64(block.timestamp)) - released();
}
/**
* @dev Getter for the amount of releasable `token` tokens. `token` should be the address of an
* IERC20 contract.
*/
function releasable(address token) public view virtual returns (uint256) {
return vestedAmount(token, uint64(block.timestamp)) - released(token);
}
/**将当前可释放的eth份额发放给用户
* @dev Release the native token (ether) that have already vested.
*
* Emits a {EtherReleased} event.
*/
function release() public virtual {
uint256 amount = releasable();
_released += amount;
emit EtherReleased(amount);
Address.sendValue(payable(beneficiary()), amount);
}
/**将当前可释放的erc20份额发放给用户
* @dev Release the tokens that have already vested.
*
* Emits a {ERC20Released} event.
*/
function release(address token) public virtual {
uint256 amount = releasable(token);
_erc20Released[token] += amount;
emit ERC20Released(token, amount);
SafeERC20.safeTransfer(IERC20(token), beneficiary(), amount);
}
/**已发放的eth份额
* @dev Calculates the amount of ether that has already vested. Default implementation is a linear vesting curve.
*/
function vestedAmount(uint64 timestamp) public view virtual returns (uint256) {
return _vestingSchedule(address(this).balance + released(), timestamp);
}
/**已发放的erc20份额
* @dev Calculates the amount of tokens that has already vested. Default implementation is a linear vesting curve.
*/
function vestedAmount(address token, uint64 timestamp) public view virtual returns (uint256) {
return _vestingSchedule(IERC20(token).balanceOf(address(this)) + released(token), timestamp);
}
/**释放计划,默认线性释放
* @dev Virtual implementation of the vesting formula. This returns the amount vested, as a function of time, for
* an asset given its total historical allocation.
*/
function _vestingSchedule(uint256 totalAllocation, uint64 timestamp) internal view virtual returns (uint256) {
if (timestamp < start()) {
return 0;
} else if (timestamp > start() + duration()) {
return totalAllocation;
} else {
return (totalAllocation * (timestamp - start())) / duration();
}
}
}