[功能重构]: 重构 HTTP 客户端和 TCP 客户端相关代码，优化结构与功能

- 重构 `HttpClient` 类，引入 PIMPL 模式，隐藏实现细节，便于维护和扩展
    - 将私有成员变量和相关函数封装到 `HttpClientPrivate` 类中
    - 优化 HTTP 请求相关函数的实现，如 `get`、`post`、`put` 等
    - 新增 `download`、`upload_put`、`upload_post` 等函数，支持文件下载和上传
- 重构 `HttpClientAsync` 类，引入 PIMPL 模式，优化异步请求处理逻辑
    - 封装异步请求相关数据和函数到 `HttpClientAsyncPrivate` 类
    - 优化异步请求的发起、处理和回调机制
    - 新增异步文件下载和上传相关功能
- 新增 `file_utils.hpp` 和 `file_utils.cc` 文件，提供文件操作相关工具函数
    - `createFile`：创建并写入文件
    - `removeFile`：删除文件
    - `assertFileData`：断言文件内容
    - `formatBytes`：格式化字节大小
- 修改 `CMakeLists.txt` 文件，调整目标链接库和源文件列表，适应代码重构后的变化
- 更新相关测试文件，如 `httpclient_test.cc`、`httpclient_async_test.cc`、`httpclient_file_test.cc`、`httpclient_async_file_test.cc` 等，以适配重构后的类接口和功能
- 重构 `TcpClient` 类，引入 PIMPL 模式，优化 TCP 客户端功能实现
    - 封装私有成员到 `TcpClientPrivate` 类，简化类结构
    - 优化连接、发送、接收等函数的实现，提高代码可读性和可维护性

Author: RealChuan

Curl/CMakeLists.txt

@@ -1,9 +1,32 @@
 add_executable(tcpclient_test tcpclient_test.cc tcpclient.cc tcpclient.hpp)
-target_link_libraries(tcpclient_test PRIVATE CURL::libcurl)
+target_link_libraries(
+  tcpclient_test PRIVATE CURL::libcurl GTest::gtest GTest::gtest_main
+                         GTest::gmock GTest::gmock_main)
 
-add_executable(httpclient_test httpclient_test.cc httpclient.cc httpclient.hpp)
-target_link_libraries(httpclient_test PRIVATE CURL::libcurl)
+set(HttpClientSource file_utils.cc file_utils.hpp httpclient.cc httpclient.hpp)
 
-add_executable(httpclient_async_test httpclient_async_test.cc
-                                     httpclient_async.cc httpclient_async.hpp)
-target_link_libraries(httpclient_async_test PRIVATE CURL::libcurl)
+add_executable(httpclient_test ${HttpClientSource} httpclient_test.cc)
+target_link_libraries(
+  httpclient_test PRIVATE CURL::libcurl GTest::gtest GTest::gtest_main
+                          GTest::gmock GTest::gmock_main)
+
+add_executable(httpclient_file_test ${HttpClientSource} httpclient_file_test.cc)
+target_link_libraries(
+  httpclient_file_test PRIVATE CURL::libcurl GTest::gtest GTest::gtest_main
+                               GTest::gmock GTest::gmock_main)
+
+set(HttpClientAsyncSource file_utils.cc file_utils.hpp httpclient_async.cc
+                          httpclient_async.hpp)
+
+add_executable(httpclient_async_test ${HttpClientAsyncSource}
+                                     httpclient_async_test.cc)
+target_link_libraries(
+  httpclient_async_test PRIVATE CURL::libcurl GTest::gtest GTest::gtest_main
+                                GTest::gmock GTest::gmock_main)
+
+add_executable(httpclient_async_file_test ${HttpClientAsyncSource}
+                                          httpclient_async_file_test.cc)
+target_link_libraries(
+  httpclient_async_file_test
+  PRIVATE CURL::libcurl GTest::gtest GTest::gtest_main GTest::gmock
+          GTest::gmock_main)

Curl/file_utils.cc

@@ -0,0 +1,57 @@
+#include "file_utils.hpp"
+
+#include <gtest/gtest.h>
+
+#include <filesystem>
+#include <fstream>
+#include <iostream>
+
+void createFile(const std::string &filename, const std::string &data)
+{
+    auto filepath = std::filesystem::current_path() / filename;
+    std::ofstream file(filepath);
+    if (!file.is_open()) {
+        std::cerr << "Cannot open the file: " << filepath << std::endl;
+        return;
+    }
+    file << data;
+    file.close();
+}
+
+void removeFile(const std::string &filename)
+{
+    auto filepath = std::filesystem::current_path() / filename;
+    if (std::filesystem::exists(filepath)) {
+        std::filesystem::remove(filepath);
+    }
+}
+
+void assertFileData(const std::string &filename, const std::string &data)
+{
+    auto filepath = std::filesystem::current_path() / filename;
+    std::ifstream file(filepath);
+    if (!file.is_open()) {
+        std::cerr << "Cannot open the file: " << filepath << std::endl;
+        return;
+    }
+    std::string fileData((std::istreambuf_iterator<char>(file)), (std::istreambuf_iterator<char>()));
+    file.close();
+    EXPECT_EQ(fileData, data);
+}
+
+auto formatBytes(double value, int precision) -> std::string
+{
+    std::vector<std::string> units = {"B", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"};
+
+    int i = 0;
+    while (value > 1024) {
+        value /= 1024;
+        i++;
+    }
+
+    std::ostringstream out;
+    out.precision(precision);
+    out << std::fixed << value;
+
+    return out.str() + " " + units[i];
+}

Curl/file_utils.hpp

@@ -0,0 +1,11 @@
+#pragma once
+
+#include <string>
+
+void createFile(const std::string &filename, const std::string &data);
+
+void removeFile(const std::string &filename);
+
+void assertFileData(const std::string &filename, const std::string &data);
+
+auto formatBytes(double value, int precision = 2) -> std::string;