ndn-js-contrib/src/DataStructures/util/WebSocketBrowserTransport.js

Reusable 'Classes' for Named Data Networking: NameTree, PIT, FIB, ContentStore, Interfaces, and Transports

/**
 * Copyright (C) 2013-2014 Regents of the University of California.
 * @author: Wentao Shang
 * See COPYING for copyright and distribution information.
 */
var ElementReader = require("ndn-js/js/encoding/element-reader.js").ElementReader
  , Transport = require("ndn-js/js/transport/transport.js").Transport
  , WebSocket = require("ws") || WebSocket;

/** ServerSide websocket transport,
 *@constructor
 *@param {WebSocket} ws a connected websocket
 *@returns {Transport} the transport
 */
var WebSocketServerTransport = function WebSocketServerTransport(socket)
{
  var Self = this;
  Transport.call(this);
  if (typeof socket === "string"){
    if (socket.split(":").length === 2){
      socket = socket + ":8686";
    }
    this.ws = socket;
  } else{
    this.ws = socket;
  }

  this.connectionInfo = new WebSocketServerTransport.ConnectionInfo(socket);

  return this;
};

/**
 *@property {String} protocolKey "wsServer"
 */


WebSocketServerTransport.prototype = new Transport();
WebSocketServerTransport.prototype.name = "WebSocketServerTransport";

WebSocketServerTransport.ConnectionInfo = function WebSocketServerTransportConnectionInfo(socket){
  Transport.ConnectionInfo.call(this);
  this.socket = socket;
};

WebSocketServerTransport.ConnectionInfo.prototype = new Transport.ConnectionInfo();
WebSocketServerTransport.ConnectionInfo.prototype.name = "WebSocketServerTransport.ConnectionInfo";

WebSocketServerTransport.ConnectionInfo.prototype.getSocket = function()
{
  return this.socket;
};

WebSocketServerTransport.prototype.connect = function(connectionInfo,face, onopenCallback, onClose)
{
  //console.log("WebSocketBrowserTransport.connect called", connectionInfo, face, this.ws)
  this.elementReader = new ElementReader(face);
  if (typeof this.ws === "string")
    this.ws = new WebSocket(this.ws);


  this.ws.binaryType = "arraybuffer";
  var self = this;
  face.readyStatus = 2;
  if (this.ws.readyState != 1)
    this.ws.onopen = function(){
      console.log("websocket open")
      onopenCallback();
    }
  else
    onopenCallback();

  //console.log("here2", this.ws.readyState)

  this.ws.onmessage = function(evt) {
    //console.log(evt);
    var buf  = evt.data;
    if (evt.currentTarget.binaryType === "arraybuffer") {
      //debug.debug("got message");
      // Make a copy of data (maybe a customBuf or a String)

      var buf = new Buffer(new Uint8Array(buf));
      try {
        //console.log('elementReader')
        // Find the end of the binary XML element and call face.onReceivedElement.
        self.elementReader.onReceivedData(buf);

      } catch (ex) {
        console.log("NDN.WebSocketServerTransport.ondata exception: " , ex);
        return;
      }
    }
  };

  this.ws.onerror = function(er) {
    console.log("error", er)
  };

  this.ws.onclose = function() {

    self.ws = null;

    onClose();
  };

};

/**
 * Send data.
 */
WebSocketServerTransport.prototype.send = function(/*Buffer*/ data)
{
  //console.log("sending",data)
  try{
    this.ws.send(data.buffer.slice(data.byteOffset), {binary: true});
  }catch (er){
    console.log('connection is not established.', er);
  }
};

/**
 * Close transport
 */
WebSocketServerTransport.prototype.close = function()
{
  try {
    this.ws.end();
  } catch (er){
    console.log("error closing wsServer transport",er);
  }

  this.onClose();
  console.log('WS connection closed.');
};

module.exports = WebSocketServerTransport;