C++ Socket库数据压缩实现

在C++中，使用Socket库进行数据压缩可以通过结合zlib库来实现。zlib是一个广泛使用的压缩库，提供了丰富的压缩和解压缩功能。下面是一个简单的示例，展示了如何在C++ Socket服务器中使用zlib进行数据压缩。

1. 首先，确保已经安装了zlib库。在大多数Linux发行版中，可以使用包管理器安装，例如在Ubuntu中输入以下命令：

sudo apt-get install zlib1g-dev

2. 创建一个C++文件，例如server.cpp，并包含必要的头文件：

#include <iostream>
#include <string>
#include <vector>
#include <zlib.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>

3. 定义一个函数来压缩数据：

std::vector<char> compressData(const std::string &data) {
    z_stream zs;
    zs.zalloc = Z_NULL;
    zs.zfree = Z_NULL;
    zs.opaque = Z_NULL;
    zs.avail_in = data.size();
    zs.next_in = reinterpret_cast<Bytef *>(const_cast<char *>(data.c_str()));

    std::vector<char> compressedData;
    const int bufferSize = 1024;
    char buffer[bufferSize];

    do {
        zs.avail_out = bufferSize;
        zs.next_out = reinterpret_cast<Bytef *>(buffer);

        int ret = deflate(&zs, Z_FINISH);
        if (ret != Z_OK && ret != Z_STREAM_END) {
            std::cerr << "Error compressing data" << std::endl;
            break;
        }

        compressedData.insert(compressedData.end(), buffer, buffer + zs.total_out);
    } while (zs.avail_out == 0);

    return compressedData;
}

4. 创建一个简单的Socket服务器，接收客户端连接并对数据进行压缩：

int main() {
    int serverSocket = socket(AF_INET, SOCK_STREAM, 0);
    if (serverSocket == -1) {
        std::cerr << "Error creating socket" << std::endl;
        return 1;
    }

    struct sockaddr_in serverAddr;
    serverAddr.sin_family = AF_INET;
    serverAddr.sin_addr.s_addr = INADDR_ANY;
    serverAddr.sin_port = htons(12345);

    if (bind(serverSocket, reinterpret_cast<struct sockaddr*>(&serverAddr), sizeof(serverAddr)) == -1) {
        std::cerr << "Error binding socket" << std::endl;
        return 1;
    }

    if (listen(serverSocket, 5) == -1) {
        std::cerr << "Error listening on socket" << std::endl;
        return 1;
    }

    while (true) {
        struct sockaddr_in clientAddr;
        socklen_t clientAddrLen = sizeof(clientAddr);
        int clientSocket = accept(serverSocket, reinterpret_cast<struct sockaddr*>(&clientAddr), &clientAddrLen);
        if (clientSocket == -1) {
            std::cerr << "Error accepting client connection" << std::endl;
            continue;
        }

        char buffer[1024];
        ssize_t bytesReceived = recv(clientSocket, buffer, sizeof(buffer) - 1, 0);
        if (bytesReceived == -1) {
            std::cerr << "Error receiving data from client" << std::endl;
            close(clientSocket);
            continue;
        }

        buffer[bytesReceived] = '\0';
        std::string data(buffer);

        std::vector<char> compressedData = compressData(data);

        send(clientSocket, reinterpret_cast<const char *>(compressedData.data()), compressedData.size(), 0);
        close(clientSocket);
    }

    close(serverSocket);
    return 0;
}

5. 编译并运行服务器：

g++ server.cpp -o server -lzlib
./server

现在，服务器已经启动并监听端口12345。当客户端连接并发送数据时，服务器将使用zlib对数据进行压缩，然后将压缩后的数据发送回客户端。客户端需要解压缩接收到的数据以获取原始数据。