cryptalk/server.js

var express = require('express.io'),
    uuid = require('node-uuid'),

    app = express();app.http().io();

app.use(express.static(__dirname + '/public'));

app.io.route('room', {
    generate: function(req) {
      var room = uuid.v4();
      req.socket.emit('room:generated',room);
    },
    join: function(req) {
      if( req.data ) {
        req.socket.emit('room:joined',req.data);
        req.socket.join(req.data);
        req.socket.broadcast.to(req.data).emit('message:server', {msg:'person_joined'} );
        req.socket.current_room = req.data;
      } else {
        req.socket.emit('message:server', {msg:'command_failed'} );
      }
    },
    leave: function(req) {
      if( req.data ) {
        req.socket.emit('room:left');
        req.socket.leave(req.data);
        req.socket.broadcast.to(req.data).emit('message:server', {msg:'person_left'} );
        req.socket.current_room = undefined;
      } else {
        req.socket.emit('message:server', {msg:'command_failed'} );
      }
    },
    count: function(req) {
      if( req.socket.current_room !== undefined ) {
        // This will fail on socket.io >= 1.0
        var client_count = app.io.sockets.clients(req.socket.current_room).length;
        req.socket.emit('message:server', {msg:'person_count', payload: client_count } );
      } else {
        req.socket.emit('message:server', {msg:'command_failed'} );
      }
    }
});

app.io.route('message', {
    send: function(req) {

      // Check that the user is in a room
      if(req.data && req.data.room) {

        // Check that the message size is within bounds
        var total_msg_size = (req.data.msg) ? req.data.msg.length : 0 + (req.data.nick) ? req.data.nick.length : 0;
        if( total_msg_size <= 4096) {

          // Check that at least 100ms has passed since last message
          if( req.socket.last_message === undefined || new Date().getTime() - req.socket.last_message > 100 ) {

            req.socket.broadcast.to(req.data.room).emit('message:send', { msg: req.data.msg, nick: req.data.nick} );
            req.socket.emit('message:send', { msg: req.data.msg, nick: req.data.nick} );

            req.socket.last_message = new Date().getTime();

          } else {

            // Do not complain if message rate is too fast, that would only generate more traffic

          }

        } else {

          // Message size is out of bounds, complain
          req.socket.emit('message:server', {msg:'command_failed'} );
        }

      } 

    }

});

app.io.sockets.on('connection', function(socket) {
   socket.on('disconnect', function() {
      // Notify other users of the room
      if( socket.current_room !== undefined ) {
        socket.broadcast.to(socket.current_room).emit('message:server', {msg:'person_left'} );
      }
   });
});

app.listen(8080, function(){
  console.log('listening on *:8080');
});