C++搭建集群聊天室（十）：登录与注册

#ifndef CHATSERVICE_H_
#define CHATSERVICE_H_

#include<muduo/net/TcpConnection.h>
#include<unordered_map>
#include<functional>
#include<mutex>

#include "json.hpp"
#include "usermodel.hpp"

using json = nlohmann::json;
using namespace std;
using namespace muduo;
using namespace muduo::net;


//处理消息的事件回调方法类型
using MsgHandler = std::function<void(const TcpConnectionPtr &conn,json &js,Timestamp time)>;

//聊天服务器业务
class ChatService{
public:
    //单例模式
    static ChatService* instance();
    
    void login(const TcpConnectionPtr &conn,json &js,Timestamp time);
    void reg(const TcpConnectionPtr &conn,json &js,Timestamp time);

    //获取消息对应的处理器
    MsgHandler getHandle(int msgid);
private:

    ChatService();

    //存储消息id和对应的处理方法
    unordered_map<int,MsgHandler> _msgHanderMap;

    //存储在线用户连接
    unordered_map<int,TcpConnectionPtr> _userConnMap;
    
    //数据操作类的对象
    UserModel _usermodel;

    //定义互斥锁
    mutex _connMutex;
};


#endif

#include"chatservice.hpp"
#include"public.hpp"
#include<string>
#include<muduo/base/Logging.h>


using namespace std;
using namespace muduo;

ChatService* ChatService::instance(){
    static ChatService service;

    return &service;
}
    
//注册消息以及对应的回调操作
ChatService::ChatService(){
    _msgHanderMap.insert({LOGIN_TYPE,std::bind(&ChatService::login,this,_1,_2,_3)});
    _msgHanderMap.insert({REG_TYPE,std::bind(&ChatService::reg,this,_1,_2,_3)});
}

//获取存储消息id和对应的处理方法
MsgHandler ChatService::getHandle(int msgid){

    //日志记录
    auto it = _msgHanderMap.find(msgid);
    if(it == _msgHanderMap.end()){
        //返回一个lambda表达式，返回一个默认的空处理器，防止业务挂掉，后可做平滑升级处理        
        return [=](const TcpConnectionPtr &conn,json &js,Timestamp time){
            LOG_ERROR<<"msgid:"<<msgid<<"can not find handle!";
        };
    }
    else{
        return _msgHanderMap[msgid];
    }
}

void ChatService::login(const TcpConnectionPtr &conn,json &js,Timestamp time){
    int id = js["id"].get<int>();
    string pwd = js["password"];

    User user = _usermodel.query(id);
    if (user.getID() == id && user.getpassword() == pwd)
    {
        if (user.getstate() == "online")
        {
            // 该用户已经登录，不允许重复登录
            json response;
            response["msgid"] = LOGIN_MSG_ACK;
            response["errno"] = 2;
            response["errmsg"] = "this account is using, input another!";
            conn->send(response.dump());
        }
        else
        {   
            //添加作用域，限制锁的粒度
            {
                lock_guard<mutex> lock(_connMutex);
          
                //记录用户连接
                _userConnMap.insert({id,conn});
            }
            
            // 登录成功，更新用户状态信息 state offline=>online
            user.setstate("online");
            _usermodel.updateState(user);

            json response;
            response["msgid"] = LOGIN_MSG_ACK;
            response["errno"] = 0;
            response["id"] = user.getID();
            response["name"] = user.getname();
            
            conn->send(response.dump());
        }
    }
    else
    {
        // 该用户不存在，用户存在但是密码错误，登录失败
        json response;
        response["msgid"] = LOGIN_MSG_ACK;
        response["errno"] = 1;
        response["errmsg"] = "id or password is invalid!";
        conn->send(response.dump());
    }
}

void ChatService::reg(const TcpConnectionPtr &conn,json &js,Timestamp time){
    string name = js["name"];
    string pwd = js["password"];
    
    User _user;
    _user.setname(name);
    _user.setpassword(pwd);

    bool state = _usermodel.insert(_user);

    if(state){
        //注册成功
        json response;
        response["msgid"] = REG_MSG_ACK;
        response["errno"] = 0;
        response["id"] = _user.getID();

        conn->send(response.dump());
    }
    else{
        //注册失败
        json response;
        response["msgid"] = REG_MSG_ACK;
        response["errno"] = 1;
       
        conn->send(response.dump());
    }
}