Michael.W基于Foundry精读Openzeppelin第67期——BeaconProxy.sol

Michael.W
更新于 2024-07-23 17:05
阅读 890

BeaconProxy库是信标代理合约的实现。与ERC1967Proxy和TransparentUpgradeableProxy两种代理合约不同，信标代理合约背后的逻辑合约地址并不是存储在代理合约内，而是存储于信标合约中。信标代理合约自身只存储信标合约的地址。

### 0. 版本

[openzeppelin]：v4.8.3，[forge-std]：v1.5.6

#### 0.1 BeaconProxy.sol

Github: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v4.8.3/contracts/proxy/beacon/BeaconProxy.sol

BeaconProxy库是信标代理合约的实现。与ERC1967Proxy和TransparentUpgradeableProxy两种代理合约不同，信标代理合约背后的逻辑合约地址并不是存储在代理合约内，而是存储于信标合约中。信标代理合约自身只存储信标合约的地址（基于ERC1967标准），这样就可以实现了多代理合约对一逻辑合约的信标代理模式。

注：

- ERC1967标准详解参见：https://learnblockchain.cn/article/8581 ；
- ERC1967Proxy库详解参见：https://learnblockchain.cn/article/8594 ；
- TransparentUpgradeableProxy库详解参见：https://learnblockchain.cn/article/8770

### 1. 目标合约

继承BeaconProxy合约：

Github: https://github.com/RevelationOfTuring/foundry-openzeppelin-contracts/blob/master/src/proxy/beacon/BeaconProxy/MockBeaconProxy.sol

```solidity
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.0;

import "openzeppelin-contracts/contracts/proxy/beacon/BeaconProxy.sol";

contract MockBeaconProxy is BeaconProxy {

constructor(address beacon_, bytes memory data) payable
    BeaconProxy(beacon_, data)
    {}

function beacon() external view returns (address) {
        return _beacon();
    }

function implementation() external view returns (address) {
        return _implementation();
    }

// deprecated
    function setBeacon(address beacon_, bytes memory data) external payable {
        _setBeacon(beacon_, data);
    }
}
```

全部foundry测试合约：

Github: https://github.com/RevelationOfTuring/foundry-openzeppelin-contracts/blob/master/test/proxy/beacon/BeaconProxy/BeaconProxy.t.sol

测试使用的物料合约：

Github: https://github.com/RevelationOfTuring/foundry-openzeppelin-contracts/blob/master/test/proxy/beacon/BeaconProxy/Beacon.sol

```solidity
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.0;

import "openzeppelin-contracts/contracts/proxy/beacon/IBeacon.sol";

contract Beacon is IBeacon {
    address public implementation;

constructor(address newImplementation){
        implementation = newImplementation;
    }
}
```

Github: https://github.com/RevelationOfTuring/foundry-openzeppelin-contracts/blob/master/test/proxy/beacon/BeaconProxy/Implementation.sol

```solidity
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.0;

interface IImplementation {
    event ChangeStorageUint(uint, uint);
}

contract Implementation is IImplementation {
    // storage
    uint public i;

function __Implementation_init(uint i_) external {
        i = i_;
    }

function addI(uint i_) external payable {
        i += i_;
        emit ChangeStorageUint(i, msg.value);
    }
}
```

### 2. 代码精读

#### 2.1 constructor(address beacon, bytes memory data)

设置信标合约地址为beacon。如果data不为空，则随后以data为calldata执行一次delegatecall到存储在beacon中的逻辑合约地址上。

注：信标合约beacon必须实现IBeacon接口且beacon地址与其内部存储的逻辑合约地址必须是合约地址，否则revert。

```solidity
    constructor(address beacon, bytes memory data) payable {
        // 调用ERC1967Upgrade._upgradeBeaconToAndCall()来设置信标合约地址。如果data不为空，则随后以data为calldata执行一次delegatecall到存储在信标合约中的逻辑合约地址上
        // 注：ERC1967Upgrade._upgradeBeaconToAndCall()详解参见：https://learnblockchain.cn/article/8581
        _upgradeBeaconToAndCall(beacon, data, false);
    }
```

**foundry代码验证：**

```solidity
contract BeaconProxyTest is Test, IERC1967, IImplementation {
    Implementation private _implementation = new Implementation();
    Beacon private _beacon = new Beacon(address(_implementation));
    MockBeaconProxy private _testing = new MockBeaconProxy(
        address(_beacon),
        abi.encodeCall(
            _implementation.__Implementation_init,
            (1024)
        )
    );

function test_ConstructorWithEmptyData() external {
        vm.expectEmit();
        emit IERC1967.BeaconUpgraded(address(_beacon));

_testing = new MockBeaconProxy(address(_beacon), "");
        assertEq(Implementation(address(_testing)).i(), 0);

// revert if beacon is not an contract
        vm.expectRevert("ERC1967: new beacon is not a contract");
        new MockBeaconProxy(address(1024), "");

// revert if implementation is not an contract
        _beacon = new Beacon(address(1024));
        vm.expectRevert("ERC1967: beacon implementation is not a contract");
        new MockBeaconProxy(address(_beacon), "");

// revert if beacon isn't an IBeacon contract
        vm.expectRevert();
        new MockBeaconProxy(address(this), "");
    }

function test_ConstructorWithData() external {
        uint ethValue = 1024;
        bytes memory data = abi.encodeCall(
            _implementation.addI,
            (2048)
        );

vm.expectEmit();
        emit IERC1967.BeaconUpgraded(address(_beacon));
        vm.expectEmit();
        emit IImplementation.ChangeStorageUint(2048, ethValue);

_testing = new MockBeaconProxy{value: ethValue}(
            address(_beacon),
            data
        );
        assertEq(Implementation(address(_testing)).i(), 2048);
        assertEq(address(_testing).balance, ethValue);

// revert if beacon is not an contract
        vm.expectRevert("ERC1967: new beacon is not a contract");
        new MockBeaconProxy{value: ethValue}(
            address(1024),
            data
        );

// revert if beacon isn't an IBeacon contract
        vm.expectRevert();
        new MockBeaconProxy{value: ethValue}(
            address(this),
            data
        );
    }
}
```

#### 2.2 _beacon() internal

返回当前的信标合约地址。

```solidity
    function _beacon() internal view virtual returns (address) {
        // 调用ERC1967Upgrade._getBeacon()来返回信标合约地址
        // 注：ERC1967Upgrade._getBeacon()详解参见：https://learnblockchain.cn/article/8581
        return _getBeacon();
    }
```

**foundry代码验证：**

```solidity
contract BeaconProxyTest is Test {
    Implementation private _implementation = new Implementation();
    Beacon private _beacon = new Beacon(address(_implementation));
    MockBeaconProxy private _testing = new MockBeaconProxy(
        address(_beacon),
        abi.encodeCall(
            _implementation.__Implementation_init,
            (1024)
        )
    );

function test_Beacon() external {
        assertEq(_testing.beacon(), address(_beacon));
    }
}
```

#### 2.3 _implementation() internal

重写`Proxy._implementation()`方法，返回当前代理合约背后的存储在信标合约中的逻辑合约地址。在Proxy的fallback处理中会将对本合约的全部call都delegatecall到_implementation()返回的地址上。

注：Proxy._implementation()及其fallback处理详解参见：https://learnblockchain.cn/article/8469

```solidity
    function _implementation() internal view virtual override returns (address) {
        // 调用信标合约的implementation()方法获得逻辑合约地址
        return IBeacon(_getBeacon()).implementation();
    }
```

**foundry代码验证：**

function test_Implementation() external {
        assertEq(_testing.implementation(), _beacon.implementation());
        assertEq(_testing.implementation(), address(_implementation));
    }
}
```

#### 2.4 _setBeacon(address beacon, bytes memory data) internal

更换信标合约地址为beacon。如果data不为空，则随后以data为calldata执行一次delegatecall到存储在beacon中的逻辑合约地址上。

该方法目前**已弃用**。因为对于信标代理合约而言，其信标合约地址往往是固定不变的。想要升级更换逻辑合约，往往是在信标合约中进行升级操作。

注：信标合约beacon必须实现IBeacon接口且beacon地址与其内部存储的逻辑合约地址必须是合约地址，否则revert。

```solidity
    function _setBeacon(address beacon, bytes memory data) internal virtual {
        // 调用ERC1967Upgrade._upgradeBeaconToAndCall()来设置信标合约地址。如果data不为空，则随后以data为calldata执行一次delegatecall到存储在信标合约中的逻辑合约地址上
        // 注：ERC1967Upgrade._upgradeBeaconToAndCall()详解参见：https://learnblockchain.cn/article/8581
        _upgradeBeaconToAndCall(beacon, data, false);
    }
```

**foundry代码验证：**

function test_SetBeacon() external {
        Implementation proxyAsImplementation = Implementation(address(_testing));
        assertEq(proxyAsImplementation.i(), 1024);

Implementation newImplementation = new Implementation();
        Beacon newBeacon = new Beacon(address(newImplementation));

// case 1: with empty data
        vm.expectEmit(address(_testing));
        emit IERC1967.BeaconUpgraded(address(newBeacon));

_testing.setBeacon(address(newBeacon), "");
        // check
        assertEq(proxyAsImplementation.i(), 1024);
        assertEq(_testing.beacon(), address(newBeacon));
        assertEq(_testing.implementation(), newBeacon.implementation());
        assertEq(_testing.implementation(), address(newImplementation));

// case 2: with data
        uint ethValue = 1024;
        assertEq(address(_testing).balance, 0);

vm.expectEmit(address(_testing));
        emit IERC1967.BeaconUpgraded(address(_beacon));
        vm.expectEmit(address(_testing));
        emit IImplementation.ChangeStorageUint(1024 + 2048, ethValue);

_testing.setBeacon{value: ethValue}(
            address(_beacon),
            abi.encodeCall(
                _implementation.addI,
                (2048)
            )
        );
        // check
        assertEq(proxyAsImplementation.i(), 1024 + 2048);
        assertEq(_testing.beacon(), address(_beacon));
        assertEq(_testing.implementation(), _beacon.implementation());
        assertEq(_testing.implementation(), address(_implementation));
        assertEq(address(_testing).balance, ethValue);

// case 3: revert if beacon is not an contract
        vm.expectRevert("ERC1967: new beacon is not a contract");
        _testing.setBeacon(
            address(1024),
            ""
        );

// case 4: revert if implementation is not an contract
        newBeacon = new Beacon(address(1024));
        vm.expectRevert("ERC1967: beacon implementation is not a contract");
        _testing.setBeacon(
            address(newBeacon),
            ""
        );

// case 5: revert if beacon isn't an IBeacon contract
        vm.expectRevert();
        _testing.setBeacon(
            address(this),
            ""
        );
    }
}
```

ps:
本人热爱图灵，热爱中本聪，热爱V神。
以下是我个人的公众号，如果有技术问题可以关注我的公众号来跟我交流。
同时我也会在这个公众号上每周更新我的原创文章，喜欢的小伙伴或者老伙计可以支持一下！
如果需要转发，麻烦注明作者。十分感谢！

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公众号名称：后现代泼痞浪漫主义奠基人

0. 版本

[openzeppelin]：v4.8.3，[forge-std]：v1.5.6

0.1 BeaconProxy.sol

Github: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v4.8.3/contracts/proxy/beacon/BeaconProxy.sol

注：

ERC1967标准详解参见：https://learnblockchain.cn/article/8581 ；
ERC1967Proxy库详解参见：https://learnblockchain.cn/article/8594 ；
TransparentUpgradeableProxy库详解参见：https://learnblockchain.cn/article/8770

1. 目标合约

继承BeaconProxy合约：

Github: https://github.com/RevelationOfTuring/foundry-openzeppelin-contracts/blob/master/src/proxy/beacon/BeaconProxy/MockBeaconProxy.sol

// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.0;

import "openzeppelin-contracts/contracts/proxy/beacon/BeaconProxy.sol";

contract MockBeaconProxy is BeaconProxy {

    constructor(address beacon_, bytes memory data) payable
    BeaconProxy(beacon_, data)
    {}

    function beacon() external view returns (address) {
        return _beacon();
    }

    function implementation() external view returns (address) {
        return _implementation();
    }

    // deprecated
    function setBeacon(address beacon_, bytes memory data) external payable {
        _setBeacon(beacon_, data);
    }
}

全部foundry测试合约：

Github: https://github.com/RevelationOfTuring/foundry-openzeppelin-contracts/blob/master/test/proxy/beacon/BeaconProxy/BeaconProxy.t.sol

测试使用的物料合约：

Github: https://github.com/RevelationOfTuring/foundry-openzeppelin-contracts/blob/master/test/proxy/beacon/BeaconProxy/Beacon.sol

// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.0;

import "openzeppelin-contracts/contracts/proxy/beacon/IBeacon.sol";

contract Beacon is IBeacon {
    address public implementation;

    constructor(address newImplementation){
        implementation = newImplementation;
    }
}

Github: https://github.com/RevelationOfTuring/foundry-openzeppelin-contracts/blob/master/test/proxy/beacon/BeaconProxy/Implementation.sol

// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.0;

interface IImplementation {
    event ChangeStorageUint(uint, uint);
}

contract Implementation is IImplementation {
    // storage
    uint public i;

    function __Implementation_init(uint i_) external {
        i = i_;
    }

    function addI(uint i_) external payable {
        i += i_;
        emit ChangeStorageUint(i, msg.value);
    }
}

2. 代码精读

2.1 constructor(address beacon, bytes memory data)

设置信标合约地址为beacon。如果data不为空，则随后以data为calldata执行一次delegatecall到存储在beacon中的逻辑合约地址上。

注：信标合约beacon必须实现IBeacon接口且beacon地址与其内部存储的逻辑合约地址必须是合约地址，否则revert。

    constructor(address beacon, bytes memory data) payable {
        // 调用ERC1967Upgrade._upgradeBeaconToAndCall()来设置信标合约地址。如果data不为空，则随后以data为calldata执行一次delegatecall到存储在信标合约中的逻辑合约地址上
        // 注：ERC1967Upgrade._upgradeBeaconToAndCall()详解参见：https://learnblockchain.cn/article/8581
        _upgradeBeaconToAndCall(beacon, data, false);
    }

foundry代码验证：

contract BeaconProxyTest is Test, IERC1967, IImplementation {
    Implementation private _implementation = new Implementation();
    Beacon private _beacon = new Beacon(address(_implementation));
    MockBeaconProxy private _testing = new MockBeaconProxy(
        address(_beacon),
        abi.encodeCall(
            _implementation.__Implementation_init,
            (1024)
        )
    );

    function test_ConstructorWithEmptyData() external {
        vm.expectEmit();
        emit IERC1967.BeaconUpgraded(address(_beacon));

        _testing = new MockBeaconProxy(address(_beacon), "");
        assertEq(Implementation(address(_testing)).i(), 0);

        // revert if beacon is not an contract
        vm.expectRevert("ERC1967: new beacon is not a contract");
        new MockBeaconProxy(address(1024), "");

        // revert if implementation is not an contract
        _beacon = new Beacon(address(1024));
        vm.expectRevert("ERC1967: beacon implementation is not a contract");
        new MockBeaconProxy(address(_beacon), "");

        // revert if beacon isn't an IBeacon contract
        vm.expectRevert();
        new MockBeaconProxy(address(this), "");
    }

    function test_ConstructorWithData() external {
        uint ethValue = 1024;
        bytes memory data = abi.encodeCall(
            _implementation.addI,
            (2048)
        );

        vm.expectEmit();
        emit IERC1967.BeaconUpgraded(address(_beacon));
        vm.expectEmit();
        emit IImplementation.ChangeStorageUint(2048, ethValue);

        _testing = new MockBeaconProxy{value: ethValue}(
            address(_beacon),
            data
        );
        assertEq(Implementation(address(_testing)).i(), 2048);
        assertEq(address(_testing).balance, ethValue);

        // revert if beacon is not an contract
        vm.expectRevert("ERC1967: new beacon is not a contract");
        new MockBeaconProxy{value: ethValue}(
            address(1024),
            data
        );

        // revert if implementation is not an contract
        _beacon = new Beacon(address(1024));
        vm.expectRevert("ERC1967: beacon implementation is not a contract");
        new MockBeaconProxy{value: ethValue}(
            address(_beacon),
            data
        );

        // revert if beacon isn't an IBeacon contract
        vm.expectRevert();
        new MockBeaconProxy{value: ethValue}(
            address(this),
            data
        );
    }
}

2.2 _beacon() internal

返回当前的信标合约地址。

    function _beacon() internal view virtual returns (address) {
        // 调用ERC1967Upgrade._getBeacon()来返回信标合约地址
        // 注：ERC1967Upgrade._getBeacon()详解参见：https://learnblockchain.cn/article/8581
        return _getBeacon();
    }

foundry代码验证：

contract BeaconProxyTest is Test {
    Implementation private _implementation = new Implementation();
    Beacon private _beacon = new Beacon(address(_implementation));
    MockBeaconProxy private _testing = new MockBeaconProxy(
        address(_beacon),
        abi.encodeCall(
            _implementation.__Implementation_init,
            (1024)
        )
    );

    function test_Beacon() external {
        assertEq(_testing.beacon(), address(_beacon));
    }
}

2.3 _implementation() internal

重写Proxy._implementation()方法，返回当前代理合约背后的存储在信标合约中的逻辑合约地址。在Proxy的fallback处理中会将对本合约的全部call都delegatecall到_implementation()返回的地址上。

注：Proxy._implementation()及其fallback处理详解参见：https://learnblockchain.cn/article/8469

    function _implementation() internal view virtual override returns (address) {
        // 调用信标合约的implementation()方法获得逻辑合约地址
        return IBeacon(_getBeacon()).implementation();
    }

foundry代码验证：

contract BeaconProxyTest is Test {
    Implementation private _implementation = new Implementation();
    Beacon private _beacon = new Beacon(address(_implementation));
    MockBeaconProxy private _testing = new MockBeaconProxy(
        address(_beacon),
        abi.encodeCall(
            _implementation.__Implementation_init,
            (1024)
        )
    );

    function test_Implementation() external {
        assertEq(_testing.implementation(), _beacon.implementation());
        assertEq(_testing.implementation(), address(_implementation));
    }
}

2.4 _setBeacon(address beacon, bytes memory data) internal

更换信标合约地址为beacon。如果data不为空，则随后以data为calldata执行一次delegatecall到存储在beacon中的逻辑合约地址上。

该方法目前已弃用。因为对于信标代理合约而言，其信标合约地址往往是固定不变的。想要升级更换逻辑合约，往往是在信标合约中进行升级操作。

注：信标合约beacon必须实现IBeacon接口且beacon地址与其内部存储的逻辑合约地址必须是合约地址，否则revert。

    function _setBeacon(address beacon, bytes memory data) internal virtual {
        // 调用ERC1967Upgrade._upgradeBeaconToAndCall()来设置信标合约地址。如果data不为空，则随后以data为calldata执行一次delegatecall到存储在信标合约中的逻辑合约地址上
        // 注：ERC1967Upgrade._upgradeBeaconToAndCall()详解参见：https://learnblockchain.cn/article/8581
        _upgradeBeaconToAndCall(beacon, data, false);
    }

foundry代码验证：

contract BeaconProxyTest is Test, IERC1967, IImplementation {
    Implementation private _implementation = new Implementation();
    Beacon private _beacon = new Beacon(address(_implementation));
    MockBeaconProxy private _testing = new MockBeaconProxy(
        address(_beacon),
        abi.encodeCall(
            _implementation.__Implementation_init,
            (1024)
        )
    );

    function test_SetBeacon() external {
        Implementation proxyAsImplementation = Implementation(address(_testing));
        assertEq(proxyAsImplementation.i(), 1024);

        Implementation newImplementation = new Implementation();
        Beacon newBeacon = new Beacon(address(newImplementation));

        // case 1: with empty data
        vm.expectEmit(address(_testing));
        emit IERC1967.BeaconUpgraded(address(newBeacon));

        _testing.setBeacon(address(newBeacon), "");
        // check
        assertEq(proxyAsImplementation.i(), 1024);
        assertEq(_testing.beacon(), address(newBeacon));
        assertEq(_testing.implementation(), newBeacon.implementation());
        assertEq(_testing.implementation(), address(newImplementation));

        // case 2: with data
        uint ethValue = 1024;
        assertEq(address(_testing).balance, 0);

        vm.expectEmit(address(_testing));
        emit IERC1967.BeaconUpgraded(address(_beacon));
        vm.expectEmit(address(_testing));
        emit IImplementation.ChangeStorageUint(1024 + 2048, ethValue);

        _testing.setBeacon{value: ethValue}(
            address(_beacon),
            abi.encodeCall(
                _implementation.addI,
                (2048)
            )
        );
        // check
        assertEq(proxyAsImplementation.i(), 1024 + 2048);
        assertEq(_testing.beacon(), address(_beacon));
        assertEq(_testing.implementation(), _beacon.implementation());
        assertEq(_testing.implementation(), address(_implementation));
        assertEq(address(_testing).balance, ethValue);

        // case 3: revert if beacon is not an contract
        vm.expectRevert("ERC1967: new beacon is not a contract");
        _testing.setBeacon(
            address(1024),
            ""
        );

        // case 4: revert if implementation is not an contract
        newBeacon = new Beacon(address(1024));
        vm.expectRevert("ERC1967: beacon implementation is not a contract");
        _testing.setBeacon(
            address(newBeacon),
            ""
        );

        // case 5: revert if beacon isn't an IBeacon contract
        vm.expectRevert();
        _testing.setBeacon(
            address(this),
            ""
        );
    }
}

ps: 本人热爱图灵，热爱中本聪，热爱V神。以下是我个人的公众号，如果有技术问题可以关注我的公众号来跟我交流。同时我也会在这个公众号上每周更新我的原创文章，喜欢的小伙伴或者老伙计可以支持一下！如果需要转发，麻烦注明作者。十分感谢！