1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
| // SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;
contract Timelock{
// 事件
// 交易取消事件
event CancelTransaction(bytes32 indexed txHash, address indexed target, uint value, string signature, bytes data, uint executeTime);
// 交易执行事件
event ExecuteTransaction(bytes32 indexed txHash, address indexed target, uint value, string signature, bytes data, uint executeTime);
// 交易创建并进入队列 事件
event QueueTransaction(bytes32 indexed txHash, address indexed target, uint value, string signature, bytes data, uint executeTime);
// 修改管理员地址的事件
event NewAdmin(address indexed newAdmin);
// 状态变量
address public admin; // 管理员地址
uint public constant GRACE_PERIOD = 7 days; // 交易有效期，过期的交易作废
uint public delay; // 交易锁定时间 （秒）
mapping (bytes32 => bool) public queuedTransactions; // txHash到bool，记录所有在时间锁队列中的交易
// onlyOwner modifier
modifier onlyOwner() {
require(msg.sender == admin, "Timelock: Caller not admin");
_;
}
// onlyTimelock modifier
modifier onlyTimelock() {
require(msg.sender == address(this), "Timelock: Caller not Timelock");
_;
}
/**
* @dev 构造函数，初始化交易锁定时间 （秒）和管理员地址
*/
constructor(uint delay_) {
delay = delay_;
admin = msg.sender;
}
/**
* @dev 改变管理员地址，调用者必须是Timelock合约。
*/
function changeAdmin(address newAdmin) public onlyTimelock {
admin = newAdmin;
emit NewAdmin(newAdmin);
}
/**
* @dev 创建交易并添加到时间锁队列中。
* @param target: 目标合约地址
* @param value: 发送eth数额
* @param signature: 要调用的函数签名（function signature）
* @param data: call data，里面是一些参数
* @param executeTime: 交易执行的区块链时间戳
*
* 要求：executeTime 大于 当前区块链时间戳+delay
*/
function queueTransaction(address target, uint256 value, string memory signature, bytes memory data, uint256 executeTime) public onlyOwner returns (bytes32) {
// 检查：交易执行时间满足锁定时间
require(executeTime >= getBlockTimestamp() + delay, "Timelock::queueTransaction: Estimated execution block must satisfy delay.");
// 计算交易的唯一识别符：一堆东西的hash
bytes32 txHash = getTxHash(target, value, signature, data, executeTime);
// 将交易添加到队列
queuedTransactions[txHash] = true;
emit QueueTransaction(txHash, target, value, signature, data, executeTime);
return txHash;
}
/**
* @dev 取消特定交易。
*
* 要求：交易在时间锁队列中
*/
function cancelTransaction(address target, uint256 value, string memory signature, bytes memory data, uint256 executeTime) public onlyOwner{
// 计算交易的唯一识别符：一堆东西的hash
bytes32 txHash = getTxHash(target, value, signature, data, executeTime);
// 检查：交易在时间锁队列中
require(queuedTransactions[txHash], "Timelock::cancelTransaction: Transaction hasn't been queued.");
// 将交易移出队列
queuedTransactions[txHash] = false;
emit CancelTransaction(txHash, target, value, signature, data, executeTime);
}
/**
* @dev 执行特定交易。
*
* 要求：
* 1. 交易在时间锁队列中
* 2. 达到交易的执行时间
* 3. 交易没过期
*/
function executeTransaction(address target, uint256 value, string memory signature, bytes memory data, uint256 executeTime) public payable onlyOwner returns (bytes memory) {
bytes32 txHash = getTxHash(target, value, signature, data, executeTime);
// 检查：交易是否在时间锁队列中
require(queuedTransactions[txHash], "Timelock::executeTransaction: Transaction hasn't been queued.");
// 检查：达到交易的执行时间
require(getBlockTimestamp() >= executeTime, "Timelock::executeTransaction: Transaction hasn't surpassed time lock.");
// 检查：交易没过期
require(getBlockTimestamp() <= executeTime + GRACE_PERIOD, "Timelock::executeTransaction: Transaction is stale.");
// 将交易移出队列
queuedTransactions[txHash] = false;
// 获取call data
bytes memory callData;
if (bytes(signature).length == 0) {
callData = data;
} else {
callData = abi.encodePacked(bytes4(keccak256(bytes(signature))), data);
}
// 利用call执行交易
(bool success, bytes memory returnData) = target.call{value: value}(callData);
require(success, "Timelock::executeTransaction: Transaction execution reverted.");
emit ExecuteTransaction(txHash, target, value, signature, data, executeTime);
return returnData;
}
/**
* @dev 获取当前区块链时间戳
*/
function getBlockTimestamp() public view returns (uint) {
return block.timestamp;
}
/**
* @dev 将一堆东西拼成交易的标识符
*/
function getTxHash(
address target,
uint value,
string memory signature,
bytes memory data,
uint executeTime
) public pure returns (bytes32) {
return keccak256(abi.encode(target, value, signature, data, executeTime));
}
}
|
