go语言使用protobuf与c++做数据通信。

首先，安装google的protobuf。安装流程请参见我以前的博客

http://blog.csdn.net/eclipser1987/article/details/8525383

安装proto的go语言插件

go get code.google.com/p/goprotobuf/{proto,protoc-gen-go}

编写一个简单的事例，go与c++网络通信：

RegMessage.proto

package cn.vicky.model.seri;

message RegMessage {
    required int32 id = 1; // 主键,唯一
    required string username = 2; // 帐号
    required string password = 3; // 密码
    optional string email = 4; // 邮箱(可选)
}

执行：
protoc --cpp_out=. RegMessage.proto

protoc --go_out=. RegMessage.proto

生成对应的c++源文件和go源文件

RegMessage.pb.h

RegMessage.pb.cc

RegMessage.pb.go

go语言做客户端代码：

// Code generated by protoc-gen-go.
// source: RegMessage.proto
// DO NOT EDIT!

package main

import "fmt"
import "os"
import "net"
import proto "code.google.com/p/goprotobuf/proto"
import json "encoding/json"
import math "math"

// Reference proto, json, and math imports to suppress error if they are not otherwise used.
var _ = proto.Marshal
var _ = &json.SyntaxError{}
var _ = math.Inf

type RegMessage struct {
	Id               *int32  `protobuf:"varint,10001,req,name=id" json:"id,omitempty"`
	Username         *string `protobuf:"bytes,2,req,name=username" json:"username,omitempty"`
	Password         *string `protobuf:"bytes,3,req,name=password" json:"password,omitempty"`
	Email            *string `protobuf:"bytes,4,opt,name=email" json:"email,omitempty"`
	XXX_unrecognized []byte  `json:"-"`
}

func (m *RegMessage) Reset()         { *m = RegMessage{} }
func (m *RegMessage) String() string { return proto.CompactTextString(m) }
func (*RegMessage) ProtoMessage()    {}

func (m *RegMessage) GetId() int32 {
	if m != nil && m.Id != nil {
		return *m.Id
	}
	return 0
}

func (m *RegMessage) GetUsername() string {
	if m != nil && m.Username != nil {
		return *m.Username
	}
	return ""
}

func (m *RegMessage) GetPassword() string {
	if m != nil && m.Password != nil {
		return *m.Password
	}
	return ""
}

func (m *RegMessage) GetEmail() string {
	if m != nil && m.Email != nil {
		return *m.Email
	}
	return ""
}

func init() {
}

func main() {
	regMessage := &RegMessage{
		Id:       proto.Int32(10001),
		Username: proto.String("vicky"),
		Password: proto.String("123456"),
		Email:    proto.String("eclipser@163.com"),
	}
	buffer, err := proto.Marshal(regMessage)
	if err != nil {
		fmt.Printf("failed: %s\n", err)
		return
	}

	pTCPAddr, err := net.ResolveTCPAddr("tcp", "192.168.1.98:7070")
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error: %s", err.Error())
		return
	}
	pTCPConn, err := net.DialTCP("tcp", nil, pTCPAddr)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error: %s", err.Error())
		return
	}
	pTCPConn.Write(buffer)
}

正常情况下是不建议修改protoc生成的源文件的，我们这里图省事，直接在生成的RegMessage.pb.go添加网络发送代码。

使用C++编写简单的socket服务器：

/* 
 * File:   main.cpp
 * Author: Vicky.H
 * Email:  eclipser@163.com
 */
#include <cstdio>
#include <cstdlib>
#include <iostream>

#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <pthread.h>

#include "RegMessage.pb.h"

void* connHandler(void *pConn) {
    int* _pConn = static_cast<int*> (pConn);
    for (;;) {
        void* buf = malloc(1024);
        int n = read(*_pConn, buf, 1024);
        
        cn::vicky::model::seri::RegMessage regMessage;
        regMessage.ParseFromArray(buf, n);
        
        std::cout << regMessage.id() << std::endl;
        std::cout << regMessage.username() << std::endl;
        std::cout << regMessage.password() << std::endl;
        std::cout << regMessage.email() << std::endl;
        
        close(*_pConn);
        free(buf);
    }
    return pConn;
}

/*
 * 
 */
int main(void) {

    int sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock == -1) {
        perror("创建Socket失败!");
        return EXIT_FAILURE;
    }

    struct sockaddr_in addr;
    addr.sin_port = htons(7070);
    inet_pton(AF_INET, "192.168.1.98", &addr.sin_addr);

    int result;
    result = bind(sock, (struct sockaddr*) &addr, sizeof (struct sockaddr_in));
    if (result != 0) {
        perror("绑定地址失败！");
        return EXIT_FAILURE;
    }

    result = listen(sock, 10);
    if (result != 0) {
        perror("监听失败！");
        return EXIT_FAILURE;
    }

    for (;;) {
        int conn = accept(sock, NULL, NULL);
        if (conn == -1) {
            perror("与客户端建立连接失败!");
            continue;
        }
        pthread_t thread;
        pthread_create(&thread, NULL, connHandler, (void*) &conn);
    }

    return 0;
}

需要连接 -lpthread -lprotobuf 

分别运行c++程序，go run RegMessage.pb.go

打印:

1
vicky
123456
eclipser@163.com

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