bruml/lib/socket.io/support/socket.io-client/lib/transport.js

   1 /**
   2  * Socket.IO client
   3  *
   4  * @author Guillermo Rauch <guillermo@learnboost.com>
   5  * @license The MIT license.
   6  * @copyright Copyright (c) 2010 LearnBoost <dev@learnboost.com>
   7  */
   8
   9 // abstract
  10
  11 (function(){
  12
  13         var frame = '~m~',
  14
  15         stringify = function(message){
  16                 if (Object.prototype.toString.call(message) == '[object Object]'){
  17                         if (!('JSON' in window)){
  18                                 if ('console' in window && console.error) console.error('Trying to encode as JSON, but JSON.stringify is missing.');
  19                                 return '{ "$error": "Invalid message" }';
  20                         }
  21                         return '~j~' + JSON.stringify(message);
  22                 } else {
  23                         return String(message);
  24                 }
  25         };
  26
  27         Transport = io.Transport = function(base, options){
  28                 this.base = base;
  29                 this.options = {
  30                         timeout: 15000 // based on heartbeat interval default
  31                 };
  32                 io.util.merge(this.options, options);
  33         };
  34
  35         Transport.prototype.send = function(){
  36                 throw new Error('Missing send() implementation');
  37         };
  38
  39         Transport.prototype.connect = function(){
  40                 throw new Error('Missing connect() implementation');
  41         };
  42
  43         Transport.prototype.disconnect = function(){
  44                 throw new Error('Missing disconnect() implementation');
  45         };
  46
  47         Transport.prototype._encode = function(messages){
  48                 var ret = '', message,
  49                                 messages = io.util.isArray(messages) ? messages : [messages];
  50                 for (var i = 0, l = messages.length; i < l; i++){
  51                         message = messages[i] === null || messages[i] === undefined ? '' : stringify(messages[i]);
  52                         ret += frame + message.length + frame + message;
  53                 }
  54                 return ret;
  55         };
  56
  57         Transport.prototype._decode = function(data){
  58                 var messages = [], number, n;
  59                 do {
  60                         if (data.substr(0, 3) !== frame) return messages;
  61                         data = data.substr(3);
  62                         number = '', n = '';
  63                         for (var i = 0, l = data.length; i < l; i++){
  64                                 n = Number(data.substr(i, 1));
  65                                 if (data.substr(i, 1) == n){
  66                                         number += n;
  67                                 } else {
  68                                         data = data.substr(number.length + frame.length);
  69                                         number = Number(number);
  70                                         break;
  71                                 }
  72                         }
  73                         messages.push(data.substr(0, number)); // here
  74                         data = data.substr(number);
  75                 } while(data !== '');
  76                 return messages;
  77         };
  78
  79         Transport.prototype._onData = function(data){
  80                 this._setTimeout();
  81                 var msgs = this._decode(data);
  82                 if (msgs && msgs.length){
  83                         for (var i = 0, l = msgs.length; i < l; i++){
  84                                 this._onMessage(msgs[i]);
  85                         }
  86                 }
  87         };
  88
  89         Transport.prototype._setTimeout = function(){
  90                 var self = this;
  91                 if (this._timeout) clearTimeout(this._timeout);
  92                 this._timeout = setTimeout(function(){
  93                         self._onTimeout();
  94                 }, this.options.timeout);
  95         };
  96
  97         Transport.prototype._onTimeout = function(){
  98                 this._onDisconnect();
  99         };
 100
 101         Transport.prototype._onMessage = function(message){
 102                 if (!this.sessionid){
 103                         this.sessionid = message;
 104                         this._onConnect();
 105                 } else if (message.substr(0, 3) == '~h~'){
 106                         this._onHeartbeat(message.substr(3));
 107                 } else if (message.substr(0, 3) == '~j~'){
 108                         this.base._onMessage(JSON.parse(message.substr(3)));
 109                 } else {
 110                         this.base._onMessage(message);
 111                 }
 112         },
 113
 114         Transport.prototype._onHeartbeat = function(heartbeat){
 115                 this.send('~h~' + heartbeat); // echo
 116         };
 117
 118         Transport.prototype._onConnect = function(){
 119                 this.connected = true;
 120                 this.connecting = false;
 121                 this.base._onConnect();
 122                 this._setTimeout();
 123         };
 124
 125         Transport.prototype._onDisconnect = function(){
 126                 this.connecting = false;
 127                 this.connected = false;
 128                 this.sessionid = null;
 129                 this.base._onDisconnect();
 130         };
 131
 132         Transport.prototype._prepareUrl = function(){
 133                 return (this.base.options.secure ? 'https' : 'http')
 134                         + '://' + this.base.host
 135                         + ':' + this.base.options.port
 136                         + '/' + this.base.options.resource
 137                         + '/' + this.type
 138                         + (this.sessionid ? ('/' + this.sessionid) : '/');
 139         };
 140
 141 })();