Question

我正在学习如何使用websockets。我通过正常的ws.send从服务器返回数据到前端但我同时希望有一个设置的间隔时间来ping前端以查看clints是否仍然存在。这是我目前正在使用的代码。

ws.on('connection', function connection(ws, req) {

  ws.on('message', function incoming(message) {
    return_data = message;
    heart_beat = {status:"Accepted", currentTime:"2013-02-01T20:53:32.486Z", "heartbeatInterval":300}

    ws.send(JSON.stringify(heart_beat));
    const interval = setInterval(function ping() {
    ws.clients.forEach(function each(ws) {
      if (ws.isAlive === false) return ws.terminate();

        ws.isAlive = false;
        ws.ping('', false, true);
      });
  }, 300);
  });
});

我想等待300秒，如果前端没有响应，我会在第一次发送心跳后终止websocket

这是我的前端代码。

ws.onopen = function(){
    console.log("Connected");
}
ws.onclose = function(){
    console.log("Disconnected");
    ws.send('Disconnected');
}

现在发生的事情是，当我在前端关闭浏览器时，后端的服务器仍在ping，如果我是console.log它。

Answer 1

您必须使用 clearInterval

清除超时

以下是uWebSocket的一个工作示例：

'use strict';

const uws = require('uws');

const PORT = 3000


/*********************************************************************
*                               Server                               *
*********************************************************************/

var wsServer = new uws.Server({ 'port': PORT });

let nextId=1;

wsServer.on('connection', function(ws) {
    console.log('connection !');

    ws.id='cnx'+nextId++;

    ws.on('message', function(mess){console.log('message : '+mess); });

    ws.on('error', function(error) {
        console.log('Cannot start server');
    });

    ws.on('close', function(code, message) {
            console.log('Disconnection: ' + code + ', ' + message);
            clearInterval(ws.timer);
            });

    ws.on('pong',function(mess) { console.log(ws.id+' receive a pong : '+mess); });

    ws.timer=setInterval(function(){pingpong(ws);},1000);

});

function pingpong(ws) {
    console.log(ws.id+' send a ping');
    ws.ping('coucou',{},true);
} // end of pingpong


/*********************************************************************
*                               Client                               *
*********************************************************************/

var wsClient1 = createClient('client1');
var wsClient2 = createClient('client2');

function createClient(id) {
    var client = new uws('ws://localhost:'+PORT);
    client.id=id;
    client.on('ping',function(mess){ console.log(this.id+' receive a ping : '+mess); } );
    client.on('message',function(mess){ console.log(this.id+' receive a message : '+mess); } );
    client.on('close',function(){ console.log(this.id+' closed'); } );
    return client;
}

function closeClient(client) {
    console.log('close '+client.id); client.close();
}

setTimeout(function(){ closeClient(wsClient1); closeClient(wsClient2); wsServer.close(); },2500);

输出是：

connection !
connection !
cnx1 send a ping
cnx2 send a ping
client2 receive a ping : coucou
client1 receive a ping : coucou
cnx1 receive a pong : coucou
cnx2 receive a pong : coucou
cnx1 send a ping
cnx2 send a ping
client2 receive a ping : coucou
client1 receive a ping : coucou
cnx1 receive a pong : coucou
cnx2 receive a pong : coucou
close client1
close client2
client1 closed
client2 closed
Disconnection: 0,
Disconnection: 0,

websocket ping与节点js

1 个答案: