高效C++鉤子實現(xiàn)API過濾的方法

在C++中，我們可以使用函數(shù)指針、回調(diào)函數(shù)或者模板方法等技巧來實現(xiàn)API過濾

1. 使用函數(shù)指針：

#include <iostream>
#include <vector>
#include <functional>

// 原始API函數(shù)
void originalApiFunction(int value) {
    std::cout << "Original API function called with value: " << value << std::endl;
}

// 過濾函數(shù)類型
using ApiFilter = std::function<bool(int)>;

// 帶有過濾器的API函數(shù)
void apiFunctionWithFilter(int value, ApiFilter filter) {
    if (filter(value)) {
        originalApiFunction(value);
    } else {
        std::cout << "API function filtered out value: " << value << std::endl;
    }
}

int main() {
    // 創(chuàng)建一個過濾器，只允許偶數(shù)通過
    ApiFilter evenFilter = [](int value) { return value % 2 == 0; };

    // 使用過濾器調(diào)用API函數(shù)
    apiFunctionWithFilter(1, evenFilter); // 輸出：API function filtered out value: 1
    apiFunctionWithFilter(2, evenFilter); // 輸出：Original API function called with value: 2
    apiFunctionWithFilter(3, evenFilter); // 輸出：API function filtered out value: 3

    return 0;
}

2. 使用回調(diào)函數(shù)：

#include <iostream>
#include <vector>

// 原始API函數(shù)
void originalApiFunction(int value) {
    std::cout << "Original API function called with value: " << value << std::endl;
}

// 過濾回調(diào)函數(shù)類型
using ApiFilterCallback = std::function<bool(int)>;

// 帶有過濾器的API函數(shù)
void apiFunctionWithFilter(int value, ApiFilterCallback filterCallback) {
    if (filterCallback(value)) {
        originalApiFunction(value);
    } else {
        std::cout << "API function filtered out value: " << value << std::endl;
    }
}

int main() {
    // 創(chuàng)建一個過濾器，只允許偶數(shù)通過
    auto evenFilterCallback = [](int value) { return value % 2 == 0; };

    // 使用過濾器調(diào)用API函數(shù)
    apiFunctionWithFilter(1, evenFilterCallback); // 輸出：API function filtered out value: 1
    apiFunctionWithFilter(2, evenFilterCallback); // 輸出：Original API function called with value: 2
    apiFunctionWithFilter(3, evenFilterCallback); // 輸出：API function filtered out value: 3

    return 0;
}

3. 使用模板方法（C++11及以上）：

#include <iostream>
#include <vector>

// 原始API函數(shù)
void originalApiFunction(int value) {
    std::cout << "Original API function called with value: " << value << std::endl;
}

// 帶有過濾器的API函數(shù)模板
template<typename Filter>
void apiFunctionWithFilter(int value, Filter filter) {
    if (filter(value)) {
        originalApiFunction(value);
    } else {
        std::cout << "API function filtered out value: " << value << std::endl;
    }
}

int main() {
    // 創(chuàng)建一個過濾器，只允許偶數(shù)通過
    auto evenFilter = [](int value) { return value % 2 == 0; };

    // 使用過濾器調(diào)用API函數(shù)
    apiFunctionWithFilter(1, evenFilter); // 輸出：API function filtered out value: 1
    apiFunctionWithFilter(2, evenFilter); // 輸出：Original API function called with value: 2
    apiFunctionWithFilter(3, evenFilter); // 輸出：API function filtered out value: 3

    return 0;
}

以上三種方法都可以實現(xiàn)API過濾的功能。你可以根據(jù)自己的需求和編程風(fēng)格選擇合適的方法。