I am trying to keep track of all tcp connections that are made in my server and store it in an array.
My problem begins when some connection is closed, in this situation I should delete it from my array but I can't do it. Can anyone help me? How do I delete a socket that is stored in my array?
var net = require("net");
function Server(port) {
var self = this;
this.conections = [];
this.server = net.createServer(function(socket) {
self.conections.push(socket); //storing the socket in the array
})
this.server.listen(port);
console.log("TCP Server created on port: "+ port);
}
module.exports = Server;
After thinking for a while I realized that I could give an ID to each socket, this way I can monitor each new connection in an array and delete it in case the connection is lost.
var net = require("net");
function Server(port) {
var self = this;
this.connections = [];
this.connectionsId = 0;
this.server = net.createServer(function(socket) {
socket.id = self.connectionsId++;
self.connections.push(socket); //storing the socket in the array
})
//Event that is always trigger when the connection is ended
socket.on('close', function() {
self.connections = self.connections.filter(function(conn) {
return conn.id !== socket.id;
});
});
this.server.listen(port);
console.log("TCP Server created on port: "+ port);
}
module.exports = Server;
Hope it helps somebody!
Related
I'm trying to recreate the functionality of a hardware serial server with Node and it's actually working, but I'm getting errors from socket instances that have been closed.
Here's a simplified version of the app to show what I'm doing...
var net = require('net');
var SerialPort = require('serialport');
var connectionCounter = 0;
var port = new SerialPort('/dev/ttyUSB0', function () {
var server = net.createServer();
server.on('connection',function(socket) {
connectionCounter++;
var connNumber = connectionCounter;
socket.on('error', function () {
console.log('socket ' + connNumber + ' errored');
});
socket.on('data', function(data) {
port.write(data);
});
port.on('data', function(data) {
socket.write(data);
});
});
server.listen(8887, '127.0.0.1');
}
});
So the first chunk of code that's sent into the 8887 port works fine, and it returns the data back out through the socket. The errors start on the second chunk. In the example, I'm keeping a count of the socket instances and outputting the socket instance number with the error. So as the program runs, the number of sockets instances keeps going up. The most recent instance will eventually handle the data, but I can't figure out what I need to delete to clean up all of the previous socket instances so they'll stop trying to process the incoming data.
I've tried socket.end() and socket.destroy(), but those don't seem to work . Do I need to go as far as deleting the server itself and recreating it?
If anyone ever finds this and cares about what was going wrong, I was setting an event listener on the serialport object every time a new net socket was created. So even though I was deleting the socket every time it was closed, the serialport listener was trying to send data to all of the old deleted sockets. So the solution was to removeListeners from the serialport object upon closing the net socket.
you can use array for storing sockets later on you can delete. this is sample code hope you got the idea
var net = require('net');
var SerialPort = require('serialport');
var connectionCounter = 0;
var mySockets = [];
var port = new SerialPort('/dev/ttyUSB0', function () {
var server = net.createServer();
server.on('connection',function(socket) {
mySockets.push(socket);
connectionCounter++;
var connNumber = connectionCounter;
socket.on('error', function () {
console.log('socket ' + connNumber + ' errored');
});
socket.on('data', function(data) {
port.write(data);
});
port.on('data', function(data) {
socket.write(data);
});
});
server.listen(8887, '127.0.0.1');
}
//get the sockets you want to delete
var s = mySockets.pop();
s = null;
});
I'm fairly new to node.js and recently started to make some modules. However I've come to a point where communication between modules is required. Since this is not a problem I've encountered in the past I'm stuck with finding a clean solution.
This is the boilerplate I currently got (Left out some checks to make the code a bit smaller). The basic idea atm is joining any irc channel given by an http post.
bot.js
//Include services
var Webservice = require('./Webservice');
var Ircservice = require('./Ircservice');
//Create service instances
var webservice = new Webservice();
var ircservice = new Ircservice();
//Initialize services
webservice.init(1337);
ircservice.init('alt-irc.snoonet.org', 80, 'User');
//Handle events
ircservice.on('irc-registered', function(msg){
console.log(ircservice.connected);
ircservice.joinChannel('#testchannel')
});
ircservice.on('irc-join', function(channel){
console.log('Successfuly joined: ' + channel);
});
webservice.on('web-join', function(streamer){
ircservice.joinChannel('#' + streamer);
});
Webservice.js
var express = require('express');
var app = express();
var bodyParser = require('body-parser');
var util = require('util');
var EventEmitter = require('events').EventEmitter;
app.use(bodyParser.urlencoded({
extended: true
}));
var Webservice = function(){
EventEmitter.call(this);
};
Webservice.prototype.init = function(port){
app.listen(port, function () {
console.log('Webserver listening on ' + port);
});
this.initRoutes();
};
Webservice.prototype.initRoutes = function(){
var self = this;
//join a irc-channel
app.post('/join', function (req, res) {
var streamer = req.body.name;
self.emit('web-join', streamer);
res.send('Received')
});
};
util.inherits(Webservice, EventEmitter);
module.exports = Webservice;
Ircservice.js
var irc = require('irc');
var util = require('util');
var EventEmitter = require('events').EventEmitter;
var Ircservice = function(){
EventEmitter.call(this);
}
Ircservice.prototype.init = function(server, port, nick){
this.client = new irc.Client(server, nick, {
port: parseInt(port)
});
this.initListerners();
};
Ircservice.prototype.initListerners = function(){
var self = this;
this.client.addListener('message', function (from, to, message) {
console.log(from + ' => ' + to + ': ' + message);
});
this.client.addListener('join', function(channel, nick, message){
self.emit('irc-join', channel);
});
};
Ircservice.prototype.joinChannel = function(channel){
this.client.join(channel, null);
};
util.inherits(Ircservice, EventEmitter);
module.exports = Ircservice;
This example works perfectly, but as you can see the communication between my webservice and ircservice is handled by the bot.js. While this is perfectly fine for this example, I cannot use this method whenever I want.
Let say in the future I want to keep a list in my ircservice of all channels he has joined and display this through a webpage. I could keep a local array on my ircservice and on the join event add that channel to the array. But how do I continue on the webservice end. I can write an endpoint '/getchannels' but my webservice itself is not aware of the ircserver to get the channels (ircservice.getChannels or something similar) and firing an event in my web request doesn't feel like the way to go.
One solution that came up in my mind was passing the instances of the services to each other like webservice.setIrcservice(ircservice) and the other way around in the bot.js. But this feels like dirty code and a hard depency.
So how can I communicate between modules when I need data instantaneously and events are no option?
sorry for posting this issue again, but most of the posts related don't answer my question.
i'm having issues to use multiple connections with the socket.io
i don't get the "socket.socket.connect" method to work, yet i get feedbacks from the first connection.
Here's my structure:
var iosocket = null;
var firstconnection = true;
var ip = "http://xxx.xxx.xxx"
var ipPort = 8081
function callSocket() {
iosocket = null;
iosocket = io.connect(ip,{port:ipPort,rememberTransport:true, timeout:1500});
if (firstconnection) {
firstconnection= false;
iosocket = io.connect(ip,{port:ipPort,rememberTransport:true, timeout:1500});
iosocket.on('connect', function () {console.log("hello socket");});
iosocket.on('message', function(message) {});//end of message io.socket
iosocket.on('disconnect', function () {console.log("disconnected");});
} else {
if (iosocket.connected === true) {
console.log("heyhey still connected");
iosocket.disconnect();
}
iosocket.socket.connect(ip,{port:ipPort,rememberTransport:true,timeout:1500});
}
};
it simply doesn't get any feedback from the second connection
i simply solved that IE8 bug by adding
<!DOCTYPE html>
at the top of the html
I think I know why this isn't working. For server-side code, this doesn't seem correct for socket.io. The connect method is used for clients and not servers. I think you are trying to make the server listen on a port. In that case, you should do:
var socket = require('socket.io');
var express = require('express');
var http = require('http');
var app = express();
var server = http.createServer(app);
var io = socket.listen(server);
io.on('connection', function (client) {
client.on('someEvent', function(someVariables){
//Do something with someVariables when the client emits 'someEvent'
io.emit('anEventToClients', someData);
});
client.on('anotherEvent', function(someMoreVariables){
//Do more things with someMoreVariables when the client emits 'anotherEvent'
io.emit('anotherEventToClients', someMoreData);
});
});
server.listen(8000);
I would like to create an object with a similar data structure if possible.
Must I create a new object for every player? Could somebody tell me how?
players
players.name='John'
players.John.age='12'
players.John.adress='London ..'
players.John.telnumber='09876587655'
edit1
Sorry I know this is the basic. I just ask one more question an them i will try learn better javascript. I need to pass data stored in "event" to object."event".id (to be like players.John.id instead players.event.id)
Sorry for my bad english.
// in app.js
var fs = require('fs');
var socketio = require('socket.io');
Tail = require('tail').Tail;
var express = require('express');
var http = require('http');
var colors = require('colors');
var app = express()
, server = require('http').createServer(app)
, io = socketio.listen(server); // socket needs to listen on http server
server.listen(9099);
app.use(express.static(__dirname + '/public'));
var port = process.env.PORT || 3000;
app.listen(port, function() {
console.log('\r\n');
console.log("Express listening on port " + port +'.'.green);
});
// Routing
//app.use(express.static(__dirname));
// usernames which are currently connected to the chat
//var players = [];
var players = {};
io.sockets.on('connection', function(socket) {
// do all of your socket work in here
console.log('\r\n');
console.log("Connection".green);
var sessionid = socket.id;
console.log(sessionid);
// Success! Now listen to messages to be received
socket.on('message',function(event){
console.log('Received message:',event);
});
socket.on('add user',function(event){
console.log('New User:',event);
// we store the username in the socket session for this client
socket.username = event;
// add the client's username to the global list
players.event = {};
players.event.id = sessionid;
//players.John.foo = "yeah"
//players.John.name = "John"
console.log(players);
socket.emit('login', {});
// echo globally (all clients) that a person has connected
socket.broadcast.emit('user joined', {
username: socket.username
});
});
//socket.emit('start', 'newround');
});
edit2
Got it working.
// in app.js
var fs = require('fs');
var socketio = require('socket.io');
Tail = require('tail').Tail;
var express = require('express');
var http = require('http');
var colors = require('colors');
var app = express()
, server = require('http').createServer(app)
, io = socketio.listen(server); // socket needs to listen on http server
server.listen(9099);
app.use(express.static(__dirname + '/public'));
var port = process.env.PORT || 3000;
app.listen(port, function() {
console.log('\r\n');
console.log("Express listening on port " + port +'.'.green);
});
// Routing
//app.use(express.static(__dirname));
// usernames which are currently connected to the chat
//var players = [];
var players = {};
io.sockets.on('connection', function(socket) {
// do all of your socket work in here
console.log('\r\n');
console.log("Connection".green);
var sessionid = socket.id;
console.log(sessionid);
// Success! Now listen to messages to be received
socket.on('message',function(event){
console.log('Received message:',event);
});
socket.on('add user',function(event){
console.log('New User:',event);
// we store the username in the socket session for this client
socket.username = event;
// add the client's username to the global list
players[event] = {};
players[event].id = sessionid;
//players.John.foo = "yeah"
//players.John.name = "John"
console.log(players);
socket.emit('login', {});
// echo globally (all clients) that a person has connected
socket.broadcast.emit('user joined', {
username: socket.username
});
});
//socket.emit('start', 'newround');
});
You're looking for a players object, with individual players referenced by name. So:
var players = {};
players['John'] = {
'age' = 12,
'address' = 'London...',
'telnumber' = '09876587655'
};
You can also access "John" as players.John, but that gets tricky if any of the names contain spaces, etc.
Similarly, the player attributes can be accessed either via:
players.John['age'] = 13;
or
players.John.age = 13;
var name = "John";
var players = {};
players[name] = {};
players[name].age = '12';
players[name].address = "address";
players[name].telnumber = "tel";
I'm making a chat app with socket.io, and I'd like to use my custom client id, instead of the default ones (8411473621394412707, 1120516437992682114). Is there any ways of sending the custom identifier when connecting or just using something to track a custom name for each ID? Thanks!
You can create an array on the server, and store custom objects on it. For example, you could store the id created by Socket.io and a custom ID sent by each client to the server:
var util = require("util"),
io = require('/socket.io').listen(8080),
fs = require('fs'),
os = require('os'),
url = require('url');
var clients =[];
io.sockets.on('connection', function (socket) {
socket.on('storeClientInfo', function (data) {
var clientInfo = new Object();
clientInfo.customId = data.customId;
clientInfo.clientId = socket.id;
clients.push(clientInfo);
});
socket.on('disconnect', function (data) {
for( var i=0, len=clients.length; i<len; ++i ){
var c = clients[i];
if(c.clientId == socket.id){
clients.splice(i,1);
break;
}
}
});
});
in this example, you need to call storeClientInfo from each client.
<script>
var socket = io.connect('http://localhost', {port: 8080});
socket.on('connect', function (data) {
socket.emit('storeClientInfo', { customId:"000CustomIdHere0000" });
});
</script>
Hope this helps.
To set custom socket id, generateId function must be overwritten. Both of eio and engine props of Socket.io server object can be used for to manage this operation.
A simple example:
var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);
io.engine.generateId = function (req) {
// generate a new custom id here
return 1
}
io.on('connection', function (socket) {
console.log(socket.id); // writes 1 on the console
})
It seems to be it has been handled.
It must be in mind that socket id must be unpredictable and unique value with considering security and the app operations!
Extra: If socket.id is returned as undefined because of your intense processes on your generateId method, async/await combination can be used to overcome this issue on node.js version 7.6.0 and later. handshake method of node_modules/engine.io/lib/server.js file should be changed as following:
current:
// engine.io/lib/server.js
Server.prototype.generateId = function (req) {
return base64id.generateId();
};
Server.prototype.handshake = function (transportName, req) {
var id = this.generateId(req);
...
}
new:
// function assignment
io.engine.generateId = function (req) {
return new Promise(function (resolve, reject) {
let id;
// some intense id generation processes
// ...
resolve(id);
});
};
// engine.io/lib/server.js
Server.prototype.handshake = async function (transportName, req) {
var id = await this.generateId(req);
...
}
Note: At Engine.io v4.0, generateId method would accept a callback. So it would not needed to change handshake method. Only generateId method replacement is going to be enough. For instance:
io.engine.generateId = function (req, callback) {
// some intense id generation processes
// ...
callback(id);
};
In the newest socket.io (version 1.x) you can do something like this
socket = io.connect('http://localhost');
socket.on('connect', function() {
console.log(socket.io.engine.id); // old ID
socket.io.engine.id = 'new ID';
console.log(socket.io.engine.id); // new ID
});
I would use an object as a hash lookup - this will save you looping through an array
var clients = {};
clients[customId] = clientId;
var lookup = clients[customId];
Do not change the socket IDs to ones of your own choosing, it breaks the Socket.io room system entirely. It will fail silently and you'll have no clue why your clients aren't receiving the messages.
This will work with 2.2.0 and above version of Socket.IO
To set custom Socket Id, generateId function must be overwritten.
A simple example:
Server Side
var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);
io.use((socket, next) => {
io.engine.generateId = () => {
// USE ONE OF THESE
socket.handshake.query.CustomId; // this work for me
// return socket.handshake.query.CustomId;
}
next(null, true);
});
io.on('connection', function (socket) {
console.log(socket.id);
})
Clint Side
io.connect(URL, { query: "CustomId = CUSTOM ID IS HERE" })
NOTE: Keep in mind that socket id must be a unique value.
why not a simpler solution that does not need to maintain an array of connected clients and does not override internal socket id?
io.on("connection", (socket) => {
socket.on('storeClientInfo', (data) => {
console.log("connected custom id:", data.customId);
socket.customId = data.customId;
});
socket.on("disconnect", () => {
console.log("disconnected custom id:", socket.customId);
})
});
Client side
let customId = "your_custom_device_id";
socket.on("connect", () => {
socket.emit('storeClientInfo', { customId: customId });
});
or you can override the socket id, like this:
io.on('connection', function(socket){
socket.id = "YOUR_CUSTOM_ID";
});
you can see under the array:
io.sockets.sockets
Can store customId (example userId) in object format instead of for loop, this will improve performance during connection, disconnect and retrieving socketId for emitting
`
var userId_SocketId_KeyPair = {};
var socketId_UserId_KeyPair = {};
_io.on('connection', (socket) => {
console.log('Client connected');
//On socket disconnect
socket.on('disconnect', () => {
// Removing sockets
let socketId = socket.id;
let userId = socketId_UserId_KeyPair[socketId];
delete socketId_UserId_KeyPair[socketId];
if (userId != undefined) {
delete userId_SocketId_KeyPair[userId];
}
console.log("onDisconnect deleted socket with userId :" + "\nUserId,socketId :" + userId + "," + socketId);
});
//Store client info
socket.on('storeClientInfo', function (data) {
let jsonObject = JSON.parse(data);
let userId = jsonObject.userId;
let socketId = socket.id;
userId_SocketId_KeyPair[userId] = socketId;
socketId_UserId_KeyPair[socketId] = userId;
console.log("storeClientInfo called with :" + data + "\nUserId,socketId :" + userId + "," + socketId);
});
`
With this 2.2.0 version of Socket.IO, you can achieve this.
io.use((socket, next) => {
io.engine.generateId = () => socket.handshake.query.token;
next(null, true);
});
If you are trying to use a custom id to in order to communicate with a specific client then you can do this
io.on('connection', function(socket){
socket.id = "someId"
io.sockets.connected["someId"] = io.sockets.connected[socket.id];
// them emit to it by id like this
io.sockets.connected["someId"].emit("some message", "message content")
});