Merge pull request #532 from isol4te/main

Update 29: Add Calculating Method for Function Signatures with Various Parameter…
AmazingAng · May 12, 2024 · 1405824 · 1405824
2 parents 3e0ab22 + 5a22a2f
commit 1405824
Show file tree

Hide file tree

Showing 4 changed files with 158 additions and 11 deletions.
diff --git a/29_Selector/Selector.sol b/29_Selector/Selector.sol
@@ -1,9 +1,23 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.21;
 
+contract DemoContract {
+    // empty contract
+}
+
 contract Selector{
     // event 返回msg.data
     event Log(bytes data);
+    event SelectorEvent(bytes4);
+
+    // Struct User
+    struct User {
+        uint256 uid;
+        bytes name;
+    }
+
+    // Enum School
+    enum School { SCHOOL1, SCHOOL2, SCHOOL3 }
 
     // 输入参数 to: 0x2c44b726ADF1963cA47Af88B284C06f30380fC78
     function mint(address /*to*/) external{
@@ -16,10 +30,70 @@ contract Selector{
         return bytes4(keccak256("mint(address)"));
     }
 
+    // 无参数selector
+    // 输入： 无
+    // nonParamSelector() ： 0x03817936
+    function nonParamSelector() external returns(bytes4 selectorWithNonParam){
+        emit SelectorEvent(this.nonParamSelector.selector);
+        return bytes4(keccak256("nonParamSelector()"));
+    }
+
+    // elementary（基础）类型参数selector
+    // 输入：param1: 1，param2: 0
+    // elementaryParamSelector(uint256,bool) : 0x3ec37834
+    function elementaryParamSelector(uint256 param1, bool param2) external returns(bytes4 selectorWithElementaryParam){
+        emit SelectorEvent(this.elementaryParamSelector.selector);
+        return bytes4(keccak256("elementaryParamSelector(uint256,bool)"));
+    }
+
+    // fixed size（固定长度）类型参数selector
+    // 输入： param1: [1,2,3]
+    // fixedSizeParamSelector(uint256[3]) : 0xead6b8bd
+    function fixedSizeParamSelector(uint256[3] memory param1) external returns(bytes4 selectorWithFixedSizeParam){
+        emit SelectorEvent(this.fixedSizeParamSelector.selector);
+        return bytes4(keccak256("fixedSizeParamSelector(uint256[3])"));
+    }
+
+    // non-fixed size（可变长度）类型参数selector
+    // 输入： param1: [1,2,3]， param2: "abc"
+    // nonFixedSizeParamSelector(uint256[],string) : 0xf0ca01de
+    function nonFixedSizeParamSelector(uint256[] memory param1,string memory param2) external returns(bytes4 selectorWithNonFixedSizeParam){
+        emit SelectorEvent(this.nonFixedSizeParamSelector.selector);
+        return bytes4(keccak256("nonFixedSizeParamSelector(uint256[],string)"));
+    }
+
+    // mapping（映射）类型参数selector
+    // 输入：demo: 0x9D7f74d0C41E726EC95884E0e97Fa6129e3b5E99， user: [1, "0xa0b1"], count: [1,2,3], mySchool: 1
+    // mappingParamSelector(address,(uint256,bytes),uint256[],uint8) : 0xe355b0ce
+    function mappingParamSelector(DemoContract demo, User memory user, uint256[] memory count, School mySchool) external returns(bytes4 selectorWithMappingParam){
+        emit SelectorEvent(this.mappingParamSelector.selector);
+        return bytes4(keccak256("mappingParamSelector(address,(uint256,bytes),uint256[],uint8)"));
+    }
+
     // 使用selector来调用函数
-    function callWithSignature() external returns(bool, bytes memory){
-        // 只需要利用`abi.encodeWithSelector`将`mint`函数的`selector`和参数打包编码
-        (bool success, bytes memory data) = address(this).call(abi.encodeWithSelector(0x6a627842, 0x2c44b726ADF1963cA47Af88B284C06f30380fC78));
-        return(success, data);
+    function callWithSignature() external{
+        // 初始化uint256数组
+        uint256[] memory param1 = new uint256[](3);
+        param1[0] = 1;
+        param1[1] = 2;
+        param1[2] = 3;
+
+        // 初始化struct
+        User memory user;
+        user.uid = 1;
+        user.name = "0xa0b1";
+
+        // 利用abi.encodeWithSelector将函数的selector和参数打包编码
+        // 调用nonParamSelector函数
+        (bool success0, bytes memory data0) = address(this).call(abi.encodeWithSelector(0x03817936));
+        // 调用elementaryParamSelector函数
+        (bool success1, bytes memory data1) = address(this).call(abi.encodeWithSelector(0x3ec37834, 1, 0));
+        // 调用fixedSizeParamSelector函数
+        (bool success2, bytes memory data2) = address(this).call(abi.encodeWithSelector(0xead6b8bd, [1,2,3]));
+        // 调用nonFixedSizeParamSelector函数
+        (bool success3, bytes memory data3) = address(this).call(abi.encodeWithSelector(0xf0ca01de, param1, "abc"));
+        // 调用mappingParamSelector函数
+        (bool success4, bytes memory data4) = address(this).call(abi.encodeWithSelector(0xe355b0ce, 0x9D7f74d0C41E726EC95884E0e97Fa6129e3b5E99, user, param1, 1));
+        require(success0 && success1 && success2 && success3 && success4);
     }
-}
+}
diff --git a/29_Selector/img/29-2.png b/29_Selector/img/29-2.png
diff --git a/29_Selector/img/29-3.png b/29_Selector/img/29-3.png
diff --git a/29_Selector/readme.md b/29_Selector/readme.md
@@ -80,18 +80,91 @@ function mintSelector() external pure returns(bytes4 mSelector){
 
 ![method id in remix](./img/29-2.png)
 
-### 使用selector
+由于计算`method id`时，需要通过函数名和函数的参数类型来计算。在`Solidity`中，函数的参数类型主要分为：基础类型参数，固定长度类型参数，可变长度类型参数和映射类型参数。
+
+##### 基础类型参数
+`solidity`中，基础类型的参数有：`uint256`(`uint8`, ... , `uint256`)、`bool`, `address`等。在计算`method id`时，只需要计算`bytes4(keccak256("函数名(参数类型1,参数类型2,...)"))`。例如，如下函数，函数名为`elementaryParamSelector`，参数类型分别为`uint256`和`bool`。所以，只需要计算`bytes4(keccak256("elementaryParamSelector(uint256,bool)"))`便可得到此函数的`method id`。
+```solidity
+    // elementary（基础）类型参数selector
+    // 输入：param1: 1，param2: 0
+    // elementaryParamSelector(uint256,bool) : 0x3ec37834
+    function elementaryParamSelector(uint256 param1, bool param2) external returns(bytes4 selectorWithElementaryParam){
+        emit SelectorEvent(this.elementaryParamSelector.selector);
+        return bytes4(keccak256("elementaryParamSelector(uint256,bool)"));
+    }
+```
 
-我们可以利用`selector`来调用目标函数。例如我想调用`mint`函数，我只需要利用`abi.encodeWithSelector`将`mint`函数的`method id`作为`selector`和参数打包编码，传给`call`函数：
+##### 固定长度类型参数
+固定长度的参数类型通常为固定长度的数组，例如：`uint256[5]`等。例如，如下函数`fixedSizeParamSelector`的参数为`uint256[3]`。因此，在计算该函数的`method id`时，只需要通过`bytes4(keccak256("fixedSizeParamSelector(uint256[3])"))`即可。
 
 ```solidity
-function callWithSignature() external returns(bool, bytes memory){
-    (bool success, bytes memory data) = address(this).call(abi.encodeWithSelector(0x6a627842, 0x2c44b726ADF1963cA47Af88B284C06f30380fC78));
-    return(success, data);
+    // fixed size（固定长度）类型参数selector
+    // 输入： param1: [1,2,3]
+    // fixedSizeParamSelector(uint256[3]) : 0xead6b8bd
+    function fixedSizeParamSelector(uint256[3] memory param1) external returns(bytes4 selectorWithFixedSizeParam){
+        emit SelectorEvent(this.fixedSizeParamSelector.selector);
+        return bytes4(keccak256("fixedSizeParamSelector(uint256[3])"));
+    }
+```
+
+##### 可变长度类型参数
+可变长度参数类型通常为可变长的数组，例如：`address[]`、`uint8[]`、`string`等。例如，如下函数`nonFixedSizeParamSelector`的参数为`uint256[]`和`string`。因此，在计算该函数的`method id`时，只需要通过`bytes4(keccak256("nonFixedSizeParamSelector(uint256[],string)"))`即可。
+
+```solidity
+    // non-fixed size（可变长度）类型参数selector
+    // 输入： param1: [1,2,3]， param2: "abc"
+    // nonFixedSizeParamSelector(uint256[],string) : 0xf0ca01de
+    function nonFixedSizeParamSelector(uint256[] memory param1,string memory param2) external returns(bytes4 selectorWithNonFixedSizeParam){
+        emit SelectorEvent(this.nonFixedSizeParamSelector.selector);
+        return bytes4(keccak256("nonFixedSizeParamSelector(uint256[],string)"));
+    }
+```
+
+##### 映射类型参数
+映射类型参数通常有：`contract`、`enum`、`struct`等。在计算`method id`时，需要将该类型转化成为`ABI`类型。
+
+例如，如下函数`mappingParamSelector`中`DemoContract`需要转化为`address`，结构体`User`需要转化为`tuple`类型`(uint256,bytes)`，枚举类型`School`需要转化为`uint8`。因此，计算该函数的`method id`的代码为`bytes4(keccak256("mappingParamSelector(address,(uint256,bytes),uint256[],uint8)"))`。
+
+```solidity
+contract DemoContract {
+    // empty contract
 }
+
+contract Selector{
+    // Struct User
+    struct User {
+        uint256 uid;
+        bytes name;
+    }
+    // Enum School
+    enum School { SCHOOL1, SCHOOL2, SCHOOL3 }
+    ...
+    // mapping（映射）类型参数selector
+    // 输入：demo: 0x9D7f74d0C41E726EC95884E0e97Fa6129e3b5E99， user: [1, "0xa0b1"], count: [1,2,3], mySchool: 1
+    // mappingParamSelector(address,(uint256,bytes),uint256[],uint8) : 0xe355b0ce
+    function mappingParamSelector(DemoContract demo, User memory user, uint256[] memory count, School mySchool) external returns(bytes4 selectorWithMappingParam){
+        emit SelectorEvent(this.mappingParamSelector.selector);
+        return bytes4(keccak256("mappingParamSelector(address,(uint256,bytes),uint256[],uint8)"));
+    }
+    ...
+}
+```
+
+### 使用selector
+
+我们可以利用`selector`来调用目标函数。例如我想调用`elementaryParamSelector`函数，我只需要利用`abi.encodeWithSelector`将`elementaryParamSelector`函数的`method id`作为`selector`和参数打包编码，传给`call`函数：
+
+```solidity
+    // 使用selector来调用函数
+    function callWithSignature() external{
+	...
+        // 调用elementaryParamSelector函数
+        (bool success1, bytes memory data1) = address(this).call(abi.encodeWithSelector(0x3ec37834, 1, 0));
+	...
+    }
 ```
 
-在日志中，我们可以看到`mint`函数被成功调用，并输出`Log`事件。
+在日志中，我们可以看到`elementaryParamSelector`函数被成功调用，并输出`Log`事件。
 
 ![logs in remix](./img/29-3.png)