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tcp_Calculator(自定义协议，序列化，反序列化)

news 2025/11/17 7:02:56

前言：

本文实现了一个基于TCP协议的简单计算器服务器系统，主要包括以下组件：1. Socket封装类(Sock)处理网络通信基础功能；2. 自定义协议(Protocol)实现请求/响应的序列化与反序列化，支持文本和JSON两种格式；3. 计算器服务(Calculator)完成算术运算；4. TcpServer类管理服务器生命周期，采用多进程模型处理客户端请求；5. 客户端程序可发送随机算术请求并解析响应。系统实现了网络通信、协议解析、业务处理等完整流程，采用进程池处理并发请求，并包含日志记录功能。

1.封装Socket.hpp:

#pragma once#include <iostream>
#include <string>
#include <unistd.h>
#include <cstring>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include "Log.hpp"enum
{SocketErr = 2,BindErr,ListenErr,
};// TODO
const int backlog = 10;class Sock
{
public:Sock(){}~Sock(){}public:void Socket(){sockfd_ = socket(AF_INET, SOCK_STREAM, 0);if (sockfd_ < 0){lg(Fatal, "socker error, %s: %d", strerror(errno), errno);exit(SocketErr);}}void Bind(uint16_t port){struct sockaddr_in local;memset(&local, 0, sizeof(local));local.sin_family = AF_INET;local.sin_port = htons(port);local.sin_addr.s_addr = INADDR_ANY;if (bind(sockfd_, (struct sockaddr *)&local, sizeof(local)) < 0){lg(Fatal, "bind error, %s: %d", strerror(errno), errno);exit(BindErr);}}void Listen(){if (listen(sockfd_, backlog) < 0){lg(Fatal, "listen error, %s: %d", strerror(errno), errno);exit(ListenErr);}}int Accept(std::string *clientip, uint16_t *clientport){struct sockaddr_in peer;socklen_t len = sizeof(peer);int newfd = accept(sockfd_, (struct sockaddr*)&peer, &len);if(newfd < 0){lg(Warning, "accept error, %s: %d", strerror(errno), errno);return -1;}char ipstr[64];inet_ntop(AF_INET, &peer.sin_addr, ipstr, sizeof(ipstr));*clientip = ipstr;*clientport = ntohs(peer.sin_port);return newfd;}bool Connect(const std::string &ip, const uint16_t &port){struct sockaddr_in peer;memset(&peer, 0, sizeof(peer));peer.sin_family = AF_INET;peer.sin_port = htons(port);inet_pton(AF_INET, ip.c_str(), &(peer.sin_addr));int n = connect(sockfd_, (struct sockaddr*)&peer, sizeof(peer));if(n == -1) {std::cerr << "connect to " << ip << ":" << port << " error" << std::endl;return false;}return true;}void Close(){close(sockfd_);}int Fd(){return sockfd_;}private:int sockfd_;
};

2.定制协议 protocol.hpp:

2.1 Request:

2.1.1 序列化:

    bool Serialize(std::string *out){
#ifdef MySelf// 构建报文的有效载荷// struct => string, "x op y"std::string s = std::to_string(x);s += blank_space_sep;s += op;s += blank_space_sep;s += std::to_string(y);*out = s;return true;
#elseJson::Value root;root["x"] = x;root["y"] = y;root["op"] = op;// Json::FastWriter w;Json::StyledWriter w;*out = w.write(root);return true;
#endif}

2.1.1 反序列化:

 bool Deserialize(const std::string &in) // "x op y"{
#ifdef MySelfstd::size_t left = in.find(blank_space_sep);if (left == std::string::npos)return false;std::string part_x = in.substr(0, left);std::size_t right = in.rfind(blank_space_sep);if (right == std::string::npos)return false;std::string part_y = in.substr(right + 1);if (left + 2 != right)return false;op = in[left + 1];x = std::stoi(part_x);y = std::stoi(part_y);return true;
#elseJson::Value root;Json::Reader r;r.parse(in, root);x = root["x"].asInt();y = root["y"].asInt();op = root["op"].asInt();return true;
#endif}

2.2 Response:

 bool Serialize(std::string *out){
#ifdef MySelf// "result code"// 构建报文的有效载荷std::string s = std::to_string(result);s += blank_space_sep;s += std::to_string(code);*out = s;return true;
#elseJson::Value root;root["result"] = result;root["code"] = code;// Json::FastWriter w;Json::StyledWriter w;*out = w.write(root);return true;
#endif}

2.2.1 序列化:

    bool Serialize(std::string *out){
#ifdef MySelf// "result code"// 构建报文的有效载荷std::string s = std::to_string(result);s += blank_space_sep;s += std::to_string(code);*out = s;return true;
#elseJson::Value root;root["result"] = result;root["code"] = code;// Json::FastWriter w;Json::StyledWriter w;*out = w.write(root);return true;
#endif}

2.2.1 反序列化:

    bool Deserialize(const std::string &in) // "result code"{
#ifdef MySelfstd::size_t pos = in.find(blank_space_sep);if (pos == std::string::npos)return false;std::string part_left = in.substr(0, pos);std::string part_right = in.substr(pos+1);result = std::stoi(part_left);code = std::stoi(part_right);return true;
#elseJson::Value root;Json::Reader r;r.parse(in, root);//解析result = root["result"].asInt();code = root["code"].asInt();return true;
#endif}

2.3 编码和解码:

2.3.1 编码:

std::string Encode(std::string &content)
{std::string package = std::to_string(content.size());package += protocol_sep;package += content;package += protocol_sep;return package;
}

2.3.2 解码:

bool Decode(std::string &package, std::string *content)
{std::size_t pos = package.find(protocol_sep);if(pos == std::string::npos) return false;std::string len_str = package.substr(0, pos);std::size_t len = std::stoi(len_str);// package = len_str + content_str + 2std::size_t total_len = len_str.size() + len + 2;if(package.size() < total_len) return false;*content = package.substr(pos+1, len);// earse 移除报文 package.erase(0, total_len);package.erase(0, total_len);return true;
}

3. 计算方法 ServerCal.hpp:

3.1 Calculator:

先把package解码，然后发起请求来反序列化，把反序化结果调用CalculatorHelper进行计算，返回请求，再请求进行编码，最后序列化。

std::string Calculator(std::string &package){std::string content;bool r = Decode(package, &content); // "len"\n"10 + 20"\nif (!r)return "";// "10 + 20"Request req;r = req.Deserialize(content); // "10 + 20" ->x=10 op=+ y=20if (!r)return "";content = "";                          //Response resp = CalculatorHelper(req); // result=30 code=0;resp.Serialize(&content);  // "30 0"content = Encode(content); // "len"\n"30 0"return content;}

3.2 CalculatorHelper：

计算的具体实现：

 Response CalculatorHelper(const Request &req){Response resp(0, 0);switch (req.op){case '+':resp.result = req.x + req.y;break;case '-':resp.result = req.x - req.y;break;case '*':resp.result = req.x * req.y;break;case '/':{if (req.y == 0)resp.code = Div_Zero;elseresp.result = req.x / req.y;}break;case '%':{if (req.y == 0)resp.code = Mod_Zero;elseresp.result = req.x % req.y;}break;default:resp.code = Other_Oper;break;}return resp;}

4.TcpServer.hpp:

4.1 InitServer:

 bool InitServer(){listensock_.Socket();listensock_.Bind(port_);listensock_.Listen();lg(Info, "init server .... done");return true;}

4.2 Start:

一个子进程可以读取多次数据，再每次调用callback(Calculator)，得到多个info，再发出去。

    void Start(){signal(SIGCHLD, SIG_IGN);signal(SIGPIPE, SIG_IGN);while (true){std::string clientip;uint16_t clientport;int sockfd = listensock_.Accept(&clientip, &clientport);if (sockfd < 0)continue;lg(Info, "accept a new link, sockfd: %d, clientip: %s, clientport: %d", sockfd, clientip.c_str(), clientport);// 提供服务if (fork() == 0){listensock_.Close();std::string inbuffer_stream;// 数据计算while (true){char buffer[1280];ssize_t n = read(sockfd, buffer, sizeof(buffer));if (n > 0){buffer[n] = 0;inbuffer_stream += buffer;lg(Debug, "debug:\n%s", inbuffer_stream.c_str());while (true){std::string info = callback_(inbuffer_stream);if (info.empty())break;lg(Debug, "debug, response:\n%s", info.c_str());lg(Debug, "debug:\n%s", inbuffer_stream.c_str());write(sockfd, info.c_str(), info.size());}}else if (n == 0)break;elsebreak;}exit(0);}close(sockfd);}}

5.ServerCal.cpp:

static void Usage(const std::string &proc)
{std::cout << "\nUsage: " << proc << " port\n" << std::endl; 
}int main(int argc, char *argv[])
{if(argc != 2){Usage(argv[0]);exit(0);}uint16_t port = std::stoi(argv[1]);ServerCal cal;TcpServer *tsvp = new TcpServer(port, std::bind(&ServerCal::Calculator, &cal, std::placeholders::_1));tsvp->InitServer();// Daemon();daemon(0, 0);tsvp->Start();return 0;
}

6.ClientCal.cc

#include <iostream>
#include <string>
#include <ctime>
#include <cassert>
#include <unistd.h>
#include "Socket.hpp"
#include "Protocol.hpp"static void Usage(const std::string &proc)
{std::cout << "\nUsage: " << proc << " serverip serverport\n"<< std::endl;
}// ./clientcal ip port
int main(int argc, char *argv[])
{if (argc != 3){Usage(argv[0]);exit(0);}std::string serverip = argv[1];uint16_t serverport = std::stoi(argv[2]);Sock sockfd;sockfd.Socket();bool r = sockfd.Connect(serverip, serverport);if(!r) return 1;srand(time(nullptr) ^ getpid());int cnt = 1;const std::string opers = "+-*/%=-=&^";std::string inbuffer_stream;while(cnt <= 10){std::cout << "===============第" << cnt << "次测试....., " << "===============" << std::endl;int x = rand() % 100 + 1;usleep(1234);int y = rand() % 100;usleep(4321);char oper = opers[rand()%opers.size()];Request req(x, y, oper);req.DebugPrint();std::string package;req.Serialize(&package);package = Encode(package);write(sockfd.Fd(), package.c_str(), package.size());char buffer[128];ssize_t n = read(sockfd.Fd(), buffer, sizeof(buffer)); // 我们也无法保证我们能读到一个完整的报文if(n > 0){buffer[n] = 0;inbuffer_stream += buffer; // "len"\n"result code"\nstd::cout << inbuffer_stream << std::endl;std::string content;bool r = Decode(inbuffer_stream, &content); // "result code"assert(r);Response resp;r = resp.Deserialize(content);assert(r);resp.DebugPrint();}std::cout << "=================================================" << std::endl;sleep(1);cnt++;}sockfd.Close();return 0;
}