環(huán)境搭建

這樣四個功能。

但是在這里我們只實現(xiàn)新增聯(lián)系人的功能。

對于服務器端，我們同樣應該具備增刪改查的功能，這里我們也只實現(xiàn)增的功能。

這里我們需要用到一個Httplib庫：

雙方通信的流程?

約定雙方交互req/rsp

syntax = "proto3";
package base_response;message BaseResponse
{bool succes = 1;    // 返回結果string error_desc = 2; // 狀態(tài)碼
}

add_contact_request.proto

syntax = "proto3";
package add_contact_request;message AddContactRequest
{string name = 1; // 姓名int32 age = 2; // 年齡message Phone{string number = 1;enum PhoneType{MP = 0; // 移動電話TEL = 1; // 固定電話}PhoneType type = 2; // 電話類型}repeated Phone phone_numbers = 3; // 電話號碼map<string,string> remark = 4; // 備注
}

add_contact_response.proto

syntax = "proto3";
package add_contact_response;
import "base_response.proto"; // 引入base_responsemessage AddContactResponse 
{base_response.BaseResponse base_resp = 1;string uid = 2; // 聯(lián)系人的uid
}

客戶端部分：
?

定義一個異常類，用于拋異常：
ContactException.h

#pragma once#include <iostream>class ContactException
{
private:std::string message;
public:ContactException(std::string str = "A Problem") : message(str) {}std::string What() const { return message; }
};

?client.cc

#include <iostream>
#include "../add_contact_request.pb.h"
#include "../add_contact_response.pb.h"
#include "../../cpp-httplib/httplib.h"
#include "ContactException.h"using namespace std;
using namespace httplib;
using namespace add_contact_request;
using namespace add_contact_response;const string IP = "127.0.0.1";
const uint16_t PORT = 8080;void addContact();void menu()
{cout << "----------------網(wǎng)絡通訊錄------------------" << endl;cout << "選擇: 1.添加聯(lián)系人  2. 刪除聯(lián)系人  3.查找所有聯(lián)系人  4. 查找一個聯(lián)系人  0.退出" << endl;
}void addContact()
{httplib::Client cli(IP, PORT);AddContactRequest info;cout << "------------添加聯(lián)系人-------------" << endl;cout << "請輸入聯(lián)系人姓名: " << endl;string name;getline(cin, name);info.set_name(name);cout << "請輸入聯(lián)系人年齡: " << endl;int32_t age;cin >> age;cin.ignore(256, '\n'); // 清空一下緩沖區(qū)// info->set_age(age);string numbers;for (int i = 1;; ++i){cout << "請輸入聯(lián)系人的第" << i << "個號碼(直接回車終止輸入)" << endl;getline(cin, numbers);if (numbers.empty())break;cout << "請輸入這個電話的類型(1/移動電話 2/固定電話): " << endl;int num = 0;cin >> num;cin.ignore(256, '\n'); // 清空以下緩沖區(qū)add_contact_request::AddContactRequest_Phone *phone = info.add_phone_numbers();phone->set_number(numbers); // info->add_phones()返回的是一塊開辟好空間的地址// 為了代碼的可擴展性，這里使用switch而不是if語句switch (num){case 1:phone->set_type(add_contact_request::AddContactRequest_Phone_PhoneType::AddContactRequest_Phone_PhoneType_MP);break;case 2:phone->set_type(add_contact_request::AddContactRequest_Phone_PhoneType::AddContactRequest_Phone_PhoneType_TEL);break;default:cout << "選擇有誤,取默認類型" << endl;break;}}for (int i = 1;; ++i){cout << "請輸入備注" << i << "標題(直接回車退出輸入)" << endl;string remark_key;getline(cin, remark_key);if (remark_key.empty())break;cout << "請輸入備注" << i << "內容" << endl;string remark_val;getline(cin, remark_val);info.mutable_remark()->insert({remark_key, remark_val});}string str_req;if (!info.SerializePartialToString(&str_req)){// 失敗拋異常ContactException e("str_req序列化失敗!");throw(e);}// 發(fā)起Post請求auto res = cli.Post("/contacts/add", str_req, "application/protobuf");if (!res){// 失敗拋異常string str_error = "發(fā)起post請求失敗,錯誤類型: ";str_error += httplib::to_string(res.error());ContactException e(str_error);throw(e);}// 反序列化responseAddContactResponse resp;bool parse = resp.ParseFromString(res->body);if(res->status != 200 && !parse){string err_desc;err_desc += "post contact/add 失敗: ";err_desc += std::to_string(res->status);err_desc += "(";err_desc += res->reason;err_desc += ")";throw ContactException(err_desc);}else if(res->status != 200){string err_desc;err_desc += "post contact/add 失敗: ";err_desc += std::to_string(res->status);err_desc += "(";err_desc += res->reason;err_desc += ")";err_desc += resp.base_resp().error_desc();throw ContactException(err_desc);}else if(!parse){string err_desc;err_desc += "post contact/add 反序列化失敗: ";err_desc += resp.base_resp().error_desc();throw ContactException(err_desc);}cout << "新增聯(lián)系人成功,uid = " << resp.uid() << endl;
}int main()
{while (true){menu();int choose;cin >> choose;cin.ignore(256, '\n');try{switch (choose){case 1:addContact();break;case 2:case 3:case 4:break;case 0:cout << "程序退出" << endl;exit(0);default:cout << "選擇有誤" << endl;exit(-1);break;}}catch (const ContactException &e){cerr << "捕獲一個異常:操作通訊錄時!" << endl;cerr << "信息: " << e.What() << endl;}}return 0;
}

makefile:
?

all:client
client:g++ client.cc ../add_contact_request.pb.cc ../add_contact_response.pb.cc ../base_response.pb.cc -o client -std=c++11 -lpthread -lprotobuf.PHONY:clean
clean:rm -f client

?

服務器部分：
?

這里為了簡單，偷個懶，沒有使用異常了，程序出錯就直接退出

server.cc

#include <iostream>
#include <random>
#include "../../cpp-httplib/httplib.h"
#include "../add_contact_request.pb.h"
#include "../add_contact_response.pb.h"using namespace std;
using namespace httplib;
using namespace add_contact_request;
using namespace add_contact_response;static unsigned int random_char()
{// ?于隨機數(shù)引擎獲得隨機種?std::random_device rd;// mt19937是c++11新特性，它是?種隨機數(shù)算法，?法與rand()函數(shù)類似，但是mt19937// 具有速度快，周期?的特點//  作?是?成偽隨機數(shù)std::mt19937 gen(rd());// 隨機?成?個整數(shù)i 范圍[0, 255]std::uniform_int_distribution<> dis(0, 255);return dis(gen);
}
// ?成 UUID （通?唯?標識符）
static std::string generate_hex(const unsigned int len)
{std::stringstream ss;// ?成 len 個16進制隨機數(shù)，將其拼接?成for (auto i = 0; i < len; i++){const auto rc = random_char();std::stringstream hexstream;hexstream << std::hex << rc;auto hex = hexstream.str();ss << (hex.length() < 2 ? '0' + hex : hex);}return ss.str();
}void PrintPeopelInfo(const AddContactRequest &people_info)
{cout << "-----------新增聯(lián)系人信息---------------" << endl;cout << "姓名: " << people_info.name() << endl;// cout << "年齡: " << people_info.age() << endl;// 打印電話for (int j = 0; j < people_info.phone_numbers().size(); ++j){const add_contact_request::AddContactRequest_Phone &phones = people_info.phone_numbers(j);cout << "第" << j + 1 << "個電話: " << phones.number();int num = phones.type();switch (num){case add_contact_request::AddContactRequest_Phone::PhoneType::AddContactRequest_Phone_PhoneType_MP:cout << "(移動電話MP)" << endl;break;case add_contact_request::AddContactRequest_Phone::PhoneType::AddContactRequest_Phone_PhoneType_TEL:cout << "(固定電話TEL)" << endl;break;default:cerr << "未知類型" << endl;break;}}// 打印備注信息int count = 1;for (auto &pair : people_info.remark()){cout << "備注信息" << count++ << ": ";cout << "(" << pair.first << ") : " << pair.second << endl;;}// 打印未知字段const google::protobuf::Reflection *reflection = people_info.GetReflection();const google::protobuf::UnknownFieldSet &unknown_field_set = reflection->GetUnknownFields(people_info);for (int j = 0; j < unknown_field_set.field_count(); ++j){const google::protobuf::UnknownField &unknown_field = unknown_field_set.field(j);cout << "未知字段" << j + 1<< " 字段編號: " << unknown_field.number()<< " 字段類型: " << unknown_field.type();switch (unknown_field.type()){case google::protobuf::UnknownField::Type::TYPE_VARINT:cout << " 值: " << unknown_field.varint() << endl;break;case google::protobuf::UnknownField::Type::TYPE_LENGTH_DELIMITED:cout << " 值: " << unknown_field.length_delimited() << endl;break;default:cout << "未知" << endl;break;}}cout << "新增聯(lián)系人成功" << endl;
}int main()
{cout << "----------服務器啟動!----------" << endl;httplib::Server svr;// 先設置方法，再進行監(jiān)聽svr.Post("/contacts/add", [](const Request &req, Response &resp){AddContactRequest contact_req;string str_req;if (!contact_req.ParseFromString(req.body)){cerr << "/contacts/add Post,反序列化失敗!" << endl;exit(-1);}PrintPeopelInfo(contact_req); // 打印新增聯(lián)系人信息// 準備響應信息// 這里為了簡單就硬編碼設置了AddContactResponse contact_resp;contact_resp.set_uid(generate_hex(8));string str_resp;if(!contact_resp.SerializePartialToString(&str_resp)){cerr << "序列化響應信息失敗，程序退出!" << endl;exit(-1);}resp.status = 200;resp.body = str_resp;resp.set_header("Content-Type", "application/protobuf");cout << "響應構建成功,準備發(fā)送!" << endl;});svr.listen("0.0.0.0",8080);return 0;
}

在上述過程中，設計了一個能隨機生成uid的函數(shù)，可以了解一下。

makefile：

all:server
server:g++ server.cc ../add_contact_request.pb.cc ../add_contact_response.pb.cc ../base_response.pb.cc -o server -std=c++11 -lpthread -lprotobuf.PHONY:clean
clean:rm -f server

?演示效果：

客戶端的新增聯(lián)系人功能：

這里也簡化了對服務器發(fā)送過來的響應的處理，我們只打印了服務器給我們返回的聯(lián)系人的uid

服務器端的新增聯(lián)系人功能：

?

服務器受到信息后，就會對客戶端那邊設置的信息進行一個打印，然后把生成的uid發(fā)送給客戶端

總結：ProtoBuf的性能與使用場景

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