protobuf: 网络版通讯录

1.客户端

1.协议约定

2..proto文件编写

syntax = "proto3";
package Add_http_contacts;

message AddContactRequest
{
    string name = 1;
    int32 age = 2;
    //里面是电话的字段和类型
    message Phone
    {
        string num = 1;
        enum PhoneType 
        {
        MP = 0; // 移动电话
        TEL = 1; // 固定电话
        }
        PhoneType type = 2;
    }
    repeated Phone phone = 3;
}

message AddContactResponse
{
  bool success = 1;
  string error_desc = 2;
  string uuid = 3;
}

3.Makefile

server:*.cc
    g++ -o $@ $^ -std=c++11 -lpthread -lprotobuf    //-lpthread是因为引入了第三方 httplib库
.PHONY:clean
clean:
    rm -rf server

4.异常类

#include <iostream>
#include <string>

class ContactException
{
private:
    std::string _error;
public:
    ContactException(std::string err = "a problem")
    :_error(err)
    {}
    std::string What() const
    {
        return _error;
    }
};

5.client.cc

#include <iostream>
#include "httplib.h"
#include "ContactException.hpp"
#include "add_contact.pb.h"

using std::cerr;
using std::cin;
using std::cout;
using std::endl;

using namespace httplib;

#define CONTACT_HOST "82.157.3.118"
#define CONTACT_PORT 8888

void menu()
{
    std::cout << "-----------------------------------------------------" << std::endl
              << "--------------- 请选择对通讯录的操作 ----------------" << std::endl
              << "------------------ 1、新增联系⼈ --------------------" << std::endl
              << "------------------ 2、删除联系⼈ --------------------" << std::endl
              << "------------------ 3、查看联系⼈列表 ----------------" << std::endl
              << "------------------ 4、查看联系⼈详细信息 ------------" << std::endl
              << "------------------ 0、退出 --------------------------" << std::endl
              << "-----------------------------------------------------" << std::endl;
}

void BuildAddContactRequest(Add_http_contacts::AddContactRequest *req)
{
    std::cout << "--------------新增联系人--------------" << std::endl;
    std::cout << "请输入联系人的姓名: ";
    std::string name;
    getline(std::cin, name);
    req->set_name(name);

    std::cout << "请输入联系人的年龄: ";
    int age;
    std::cin >> age;
    req->set_age(age);
    std::cin.ignore(256, '\n'); // 清除缓冲区所有内容，直到'\n'，把'\n'删除后结束，或者清除256个字节直接结束

    for (int i = 0;; i++)
    {
        std::cout << "请输入联系人的电话: " << i + 1 << "(只输入回车完成电话新增): ";
        std::string number;
        getline(std::cin, number);
        if (number.empty())
            break;
        // 接收add_phone返回的phone对象
        Add_http_contacts::AddContactRequest_Phone *phone = req->add_phone();
        phone->set_num(number);

        std::cout << "请输入联系人的电话类型:(0.移动电话, 1.固定电话): ";
        int type;
        std::cin >> type;
        std::cin.ignore(256, '\n');
        switch (type)
        {
        case 0:
            phone->set_type(Add_http_contacts::AddContactRequest_Phone_PhoneType::AddContactRequest_Phone_PhoneType_MP);
            break;
        case 1:
            phone->set_type(Add_http_contacts::AddContactRequest_Phone_PhoneType::AddContactRequest_Phone_PhoneType_TEL);
            break;
        default:
            std::cout << "输入有误, 请重新根据提示输入" << std::endl;
            break;
        }
    }
}
void AddContact()
{
    Client client(CONTACT_HOST, CONTACT_PORT);
    // 构建req对象
    Add_http_contacts::AddContactRequest req;
    BuildAddContactRequest(&req);
    // 序列化
    std::string req_str;
    if (!req.SerializeToString(&req_str))
    {
        std::string errstr = "AddContact时,序列化失败";
        throw ContactException(errstr);
    }
    // 发起post请求
    auto post = client.Post("/contacts/add", req_str, "application/protobuf");
    if (!post) 
    {
        std::string err_str = "/contacts/add 链接失败,错误原因: ";
        err_str.append(httplib::to_string(post.error()));
        throw ContactException(err_str);
    }

    // 反序列化rsp
    Add_http_contacts::AddContactResponse resp;
    bool parse = resp.ParseFromString(post->body);
    if (post->status != 200 && !parse)
    {
        std::string err_str = "调用 /contact/add 失败 ";
        err_str.append(std::to_string(post->status))
            .append("(")
            .append(post->reason)
            .append(")");
        throw ContactException(err_str);
    }
    else if (post->status != 200)
    {
        std::string err_str = "调用 /contact/add 失败 ";
        err_str.append(std::to_string(post->status))
            .append("(")
            .append(post->reason)
            .append(")")
            .append("错误原因: ")
            .append(resp.error_desc());
        throw ContactException(err_str);
    }
    else if (!resp.success())
    {
        std::string err_str = "调用 /contact/add 结果异常 ";
        err_str.append("异常原因: ")
            .append(resp.error_desc());
        throw ContactException(err_str);
    }
    // 打印结果
    cout << "新增联系人成功" << "联系人id: " << resp.uuid() << endl;
}

int main()
{
    enum Option
    {
        Quit = 0,
        Add,
        Del,
        Findone,
        Findall
    };
    menu();
    cout << "---->请选择: ";
    int choose;
    cin >> choose;
    cin.ignore(256, '\n');
    try
    {
        switch (choose)
        {
        case Option::Quit:
            cout << "---->退出" << endl;
            return 1;
        case Option::Add:
            cout << "---->新增联系人" << endl;
            AddContact();
            break;
        case Option::Del:
            cout << "---->暂未实现" << endl;
            break;
        case Option::Findone:
            cout << "---->暂未实现" << endl;
            break;
        case Option::Findall:
            cout << "---->暂未实现" << endl;
            break;
        default:
            cout << "---->选择有误，请重新选择" << endl;
            break;
        };
    }
    catch (const ContactException &e)
    {
        cout << "--->出现错误, 错误原因是: " << e.What() << endl;
    }
}

2.服务端

1.UUIDUtil类

#pragma once
#include <iostream>
#include <sstream>
#include <string>
#include <random>
#include <iomanip>
#include <atomic>

namespace ns_uuid
{
    class UUIDUtil
    {
    public:
        static std::string uuid()
        {
            // 生成机器随机数对象
            std::random_device rd;
            // 用mt算法，以机器随机数对象为种子生成伪随机数对象
            std::mt19937 generator(rd());
            // 构造限定数据范围的伪随机数
            std::uniform_int_distribution<int> distribution(0, 255);
            // ⽣成8个随机数，按照特定格式组织成为16进制数字字符的字符串
            std::stringstream ss;
            for (int i = 0; i < 8; i++)
            {
                if(i == 4 || i == 6) ss << "-";
                ss << std::setw(2) << std::setfill('0') << std::hex << distribution(generator);
            }
            ss << "-";
            // 定义⼀个8字节序号，逐字节组织成为16进制数字字符的字符串
            static std::atomic<int> a(0);
            // size_t 64个bit位
            size_t cur = a.fetch_add(1);
            for (int i = 7; i >= 0; i--)
            {
                if(i == 5) ss << "-";
                ss << std::setw(2) << std::setfill('0') << std::hex << ((cur >> (i*8)) & 0xFF);
            }

            return ss.str();
        }
    };
}

2.server.cc

#include <iostream>
#include "add_contact.pb.h"
#include "ContactException.hpp"
#include <string>
#include "httplib.h"
#include "UUIDUtil.hpp"

using namespace httplib;
using namespace ns_uuid;
using std::cout;
using std::endl;



void PrintContacts(Add_http_contacts::AddContactRequest& request)
{
        std::cout << "联系人姓名：" << request.name() << std::endl;
        std::cout << "联系人年龄：" << request.age() << std::endl;
        for(int j = 0;j<request.phone_size();j++)
        {
            const Add_http_contacts::AddContactRequest_Phone phone = request.phone(j);
            std::cout << "联系人电话" << j+1  << ": "<< phone.num() << "   ";
            std::cout << "电话类型"  << ": ("<< AddContactRequest_Phone_PhoneType_Name(phone.type()) << ")" << std::endl; 
        }
}
int main()
{
    Server server;
    server.Post("/contacts/add", [](const Request &req, Response &resp)
        {
            // 反序列化request : req.body
            Add_http_contacts::AddContactRequest request;
            Add_http_contacts::AddContactResponse response;
            try
            {
                if (!request.ParseFromString(req.body))
                {
                    throw ContactException("request反序列化失败");
                }

                //新增联系人，持久化存储——————这里只是实现打印
                PrintContacts(request);

                // 序列化response
                response.set_success(true);
                
                response.set_uuid(UUIDUtil::uuid());
                std::string resp_str;
                if (!response.SerializeToString(&resp_str))
                {
                    throw ContactException("response序列化失败");
                }
                resp.status = 200;
                resp.body = resp_str;
                resp.set_header("Content-Type", "application/protobuf");
            }
            catch (const ContactException &e)
            {
                resp.status = 500;
                response.set_success(false);
                response.set_error_desc(e.What());
                std::string resp_str;
                if (response.SerializeToString(&resp_str))
                {
                    resp.body = resp_str;
                    resp.set_header("Content-Type", "application/protobuf");
                }
            }
        });

    server.listen("0.0.0.0", 8888);
    return 0;
}

3.总结