مثالی از فراخوانی چندین تابع با یک تراکنش واحد، با استفاده از نماینده تماس بگیرید
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// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;
contract MultiDelegatecall {
error DelegatecallFailed();
function multiDelegatecall(bytes[] memory data)
external
payable
returns (bytes[] memory results)
{
results = new bytes[](data.length);
for (uint256 i; i < data.length; i++) {
(bool ok, bytes memory res) = address(this).delegatecall(data[i]);
if (!ok) {
revert DelegatecallFailed();
}
results[i] = res;
}
}
}
// Why use multi delegatecall? Why not multi call?
// alice -> multi call --- call ---> test (msg.sender = multi call)
// alice -> test --- delegatecall ---> test (msg.sender = alice)
contract TestMultiDelegatecall is MultiDelegatecall {
event Log(address caller, string func, uint256 i);
function func1(uint256 x, uint256 y) external {
// msg.sender = alice
emit Log(msg.sender, "func1", x + y);
}
function func2() external returns (uint256) {
// msg.sender = alice
emit Log(msg.sender, "func2", 2);
return 111;
}
mapping(address => uint256) public balanceOf;
// WARNING: unsafe code when used in combination with multi-delegatecall
// user can mint multiple times for the price of msg.value
function mint() external payable {
balanceOf[msg.sender] += msg.value;
}
}
contract Helper {
function getFunc1Data(uint256 x, uint256 y)
external
pure
returns (bytes memory)
{
return
abi.encodeWithSelector(TestMultiDelegatecall.func1.selector, x, y);
}
function getFunc2Data() external pure returns (bytes memory) {
return abi.encodeWithSelector(TestMultiDelegatecall.func2.selector);
}
function getMintData() external pure returns (bytes memory) {
return abi.encodeWithSelector(TestMultiDelegatecall.mint.selector);
}
}