javascript - Nodejs，客户端并不总是收到服务器消息

Question

我正在设置一个非常基本的 Node 应用程序，计划是任何人都可以访问该站点并按一个字母，这将增加一个计数器。每个人都可以看到随着全世界的人们都在增加它，计数器在上升。它工作得很好，除了我一开始设置它的方式然后 Node 服务器每秒联系每个客户端 20 次，这是非常浪费的。

因此，为了避免我添加了一个条件，即计数器必须增加才能让 Node 服务器发送消息。但是，当我这样做时，消息并没有真正发送给所有客户，它们发送给客户的方式有些困惑，显然是随机顺序。

这是我的第一个 Node 应用程序，我仍在掌握它的窍门，任何人都可以用它指出正确的方向吗？问题可能出在 increment_time 函数中。

服务器部分:

var http=require('http');
var io=require('socket.io');
var fs=require('fs');

var sockFile=fs.readFileSync('text');
server=http.createServer();

//2. get request, via port, http://localhost:8000
server.on('request', function(req, res){
    console.log('request received');
    res.writeHead(200, {'content-type':'text/html'});
    res.end(sockFile);
    }); 

//have server and socket listen to port 8000.
server.listen(8000);
var socket=io.listen(server);

//the lower the number the less chatty the debug becomes.
socket.set('log level', 1); 

//initiate the counter.
counter=0;
counterp=0;


//3. on client connect.
//http://<address>/apps/press_k
socket.on('connection', function(socket){
    console.log("Client connected.");

    //increment counter on clients command.
    socket.on('s_increment_counter',function(data){
    counter++;
    console.log('New counter:'+counter);
    });

//send the counter to all clients if it has increased.
increment_time_continuously();
function increment_time(){
    //this is the condition that is to limit how often node sends to the clients,
    //but setting it on means the counter will be delivered in some erratic way 
    //to the  clients.
    //if(counter===counterp)  {return;}

    //send current counter to all clients.
    console.log("passed the equals, now broadcast.");
    //this part is clearly only sending to one of them.
    socket.emit('c_display_counter', counter);
    //client.broadcast.emit('c_display_counter', counter)
    //client.send('Welcome client');

    counterp=counter;
    }
function increment_time_continuously(){setInterval(increment_time,50);}
});

相关客户端部分:

//client_to_server:
//-tell server to increment counter.
function s_increment_counter(){
    socket.emit('s_increment_counter',{counter:0});
    }

//server_to_client:
//-when server tells to display counter, display counter.
socket.on('c_display_counter',function(counter){
    //counter=data["counter"];
    k_counter_text.attr({"text":counter});
    });

Answer 1

问题是你不存储你的连接，当你使用 socket.emit 广播时，它只会到达你的最后一个连接，你需要存储每个连接到套接字的连接(在数组或其他东西中)然后迭代通过您的所有连接并广播您想要的消息。

var http=require('http');
var io=require('socket.io');
var fs=require('fs');

var sockFile=fs.readFileSync('text');
server=http.createServer();

//2. get request, via port, http://localhost:8000
server.on('request', function(req, res){
    console.log('request received');
    res.writeHead(200, {'content-type':'text/html'});
    res.end(sockFile);
    }); 

//have server and socket listen to port 8000.
server.listen(8000);
var socket=io.listen(server);

//the lower the number the less chatty the debug becomes.
socket.set('log level', 1); 

//initiate the counter.
counter=0;
counterp=0;
connections = {};




function broadcastToConnections(){
  for(c in connections){
    var con = connections[c];
      con.emit('c_display_counter', counter);
  }
}

function connectionClose(socket){
  delete connections[socket.id];
}


//3. on client connect.
//http://<address>/apps/press_k
socket.on('connection', function(socket){
    console.log("Client connected.");

    //increment counter on clients command.
    socket.on('s_increment_counter',function(data){
      counter++;
      console.log('New counter:'+counter);

      broadcastToConnections();
    });

    connections[socket.id] = socket;//here we store our connection in connections obj

    socket.on('close', connectionClose);//we listen to close event to remove our connection from connection obj

});