/chrome/content/UdpClient.js

/*******************************************************************************

 * Copyright (c) 2012, Institute for Pervasive Computing, ETH Zurich.

 * All rights reserved.

 * 

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. Neither the name of the Institute nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 * 

 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS "AS IS" AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 * 

 * This file is part of the Copper CoAP browser.

 ******************************************************************************/

/**

 * \file

 *         Code handling the UDP communication for the CoAP protocol

 *

 * \author  Matthias Kovatsch <kovatsch@inf.ethz.ch>\author

 */



/*

 * FIXME: inputStream does not separate single datagrams.

 * Thus, increased traffic results in merged datagrams, i.e., one or more datagrams are added to the payload of the first one.

 * A workaround will probably need native code to provide a datagram handler (transport-service) that pipes them to/from Firefox.

 */ 



CopperChrome.UdpClient = function(myHost, myPort) {



	// createTransport requires plain IPv6 address

	this.host = myHost.replace(/\[/,'').replace(/\]/,'');

	this.port = myPort;

	

	this.transportService = Components.classes["@mozilla.org/network/socket-transport-service;1"].getService(Components.interfaces.nsISocketTransportService);

	this.pump = Components.classes["@mozilla.org/network/input-stream-pump;1"].createInstance(Components.interfaces.nsIInputStreamPump);

	

	this.socket = this.transportService.createTransport(["udp"], 1, this.host, this.port, null);

	

	this.outputStream = this.socket.openOutputStream(0,0,0);

	this.inputStream = this.socket.openInputStream(0, 0, 0); // 1,0,0 = OPEN_BLOCKING

	

    this.pump.init(this.inputStream, -1, -1, 0, 0, false);

	this.pump.asyncRead(this, null);

	

	return this;

};



CopperChrome.UdpClient.prototype = {



	host             : '',

	port             : -1,

	

	callback         : null,

	errorCallback    : null,

	ended            : false,

	

	transportService : null,

	pump             : null,

	socket           : null,

	outputStream     : null,

	inputStream      : null,

	sis : null,

	

	register : function(myCB) {

		this.callback = myCB;

	},

	

	registerErrorCallback : function(myCB) {

		this.errorCallback = myCB;

	},

	

	// stream observer functions

	onStartRequest : function(request, context) {

		;

	},

	

	onStopRequest : function(request, context, status) {

		this.outputStream.close();

		this.inputStream.close();

		if (!this.ended) {

			this.errorCallback({getCopperCode:function(){return 'Host/network unreachable';}});

		}

	},

	

	onDataAvailable : function(request, context, inputStream, offset, count) {

		try {

			// inputStream is for native code only, hence, using nsIScriptableInputStream

			var sis = Components.classes["@mozilla.org/scriptableinputstream;1"].createInstance(Components.interfaces.nsIScriptableInputStream);

			sis.init(inputStream);

			

			// read() cannot handle zero bytes in strings, readBytes() coming in FF4

			var byteArray = new Array(count);

			for (var i=0; i<count; i++) {

				//var ch = sis.readBytes(1); // FF4

				var ch = sis.read(1);

				

				byteArray[i] = ch.charCodeAt(0);

				

				// pre FF4 workaround

				if (isNaN(byteArray[i])) byteArray[i] = 0x00;

				

				//showByte(byteArray[i])

			}



			//alert(byteArray);

			dump('-receiving UDP datagram-\n');

			dump(' Length: '+count+'\n');

			dump(' -----------------------\n');

			if (this.callback) this.callback(byteArray);

			

		} catch( ex ) {

		    alert('ERROR: UdpClient.onDataAvailable ['+ex+']');

		}

	},

	

	// UdpClient functions

	shutdown : function() {

		// will also trigger onStopRequest()

		this.ended = true;

		this.outputStream.close();

		this.inputStream.close();

		this.socket.close(0);

		dump('-UDP shut down-----------\n');

	},

	

	send : function(datagram) {

		try {

			this.outputStream.write(datagram, datagram.length);

			

			dump('-sent UDP datagram------\n');

			dump(' Length: '+datagram.length+'\n');

			dump(' -----------------------\n');

		} catch (ex) {

			dump('WARNING: UdpClient.send [I/O error]\n');

			if (this.errorCallback) {

				this.errorCallback({getCopperCode:function(){return 'I/O error';}});

			}

		}

	}

};



/*

function showByte(b) {

	var str = '';

	for (var j=0; j<8; j++) {

		str = ((b & 1<<j)>0 ? '1' : '0') + str;

	}

	dump('UDP byte ' + b + ': ' + str + '\n');

}

*/