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1/*******************************************************************************
2 * Copyright (c) 2013 IBM Corp.
3 *
4 * All rights reserved. This program and the accompanying materials
5 * are made available under the terms of the Eclipse Public License v1.0
6 * and Eclipse Distribution License v1.0 which accompany this distribution.
7 *
8 * The Eclipse Public License is available at
9 *    http://www.eclipse.org/legal/epl-v10.html
10 * and the Eclipse Distribution License is available at
11 *   http://www.eclipse.org/org/documents/edl-v10.php.
12 *
13 * Contributors:
14 *    Andrew Banks - initial API and implementation and initial documentation
15 *******************************************************************************/
16
17
18// Only expose a single object name in the global namespace.
19// Everything must go through this module. Global Paho.MQTT module
20// only has a single public function, client, which returns
21// a Paho.MQTT client object given connection details.
22
23/**
24 * Send and receive messages using web browsers.
25 * <p>
26 * This programming interface lets a JavaScript client application use the MQTT V3.1 or
27 * V3.1.1 protocol to connect to an MQTT-supporting messaging server.
28 *
29 * The function supported includes:
30 * <ol>
31 * <li>Connecting to and disconnecting from a server. The server is identified by its host name and port number.
32 * <li>Specifying options that relate to the communications link with the server,
33 * for example the frequency of keep-alive heartbeats, and whether SSL/TLS is required.
34 * <li>Subscribing to and receiving messages from MQTT Topics.
35 * <li>Publishing messages to MQTT Topics.
36 * </ol>
37 * <p>
38 * The API consists of two main objects:
39 * <dl>
40 * <dt><b>{@link Paho.MQTT.Client}</b></dt>
41 * <dd>This contains methods that provide the functionality of the API,
42 * including provision of callbacks that notify the application when a message
43 * arrives from or is delivered to the messaging server,
44 * or when the status of its connection to the messaging server changes.</dd>
45 * <dt><b>{@link Paho.MQTT.Message}</b></dt>
46 * <dd>This encapsulates the payload of the message along with various attributes
47 * associated with its delivery, in particular the destination to which it has
48 * been (or is about to be) sent.</dd>
49 * </dl>
50 * <p>
51 * The programming interface validates parameters passed to it, and will throw
52 * an Error containing an error message intended for developer use, if it detects
53 * an error with any parameter.
54 * <p>
55 * Example:
56 *
57 * <code><pre>
58client = new Paho.MQTT.Client(location.hostname, Number(location.port), "clientId");
59client.onConnectionLost = onConnectionLost;
60client.onMessageArrived = onMessageArrived;
61client.connect({onSuccess:onConnect});
62
63function onConnect() {
64  // Once a connection has been made, make a subscription and send a message.
65  console.log("onConnect");
66  client.subscribe("/World");
67  message = new Paho.MQTT.Message("Hello");
68  message.destinationName = "/World";
69  client.send(message); 
70};
71function onConnectionLost(responseObject) {
72  if (responseObject.errorCode !== 0)
73	console.log("onConnectionLost:"+responseObject.errorMessage);
74};
75function onMessageArrived(message) {
76  console.log("onMessageArrived:"+message.payloadString);
77  client.disconnect(); 
78};
79 * </pre></code>
80 * @namespace Paho.MQTT
81 */
82
83if (typeof Paho === "undefined") {
84	Paho = {};
85}
86
87Paho.MQTT = (function (global) {
88
89	// Private variables below, these are only visible inside the function closure
90	// which is used to define the module. 
91
92	var version = "@VERSION@";
93	var buildLevel = "@BUILDLEVEL@";
94
95	/**
96	 * Unique message type identifiers, with associated
97	 * associated integer values.
98	 * @private
99	 */
100	var MESSAGE_TYPE = {
101		CONNECT: 1,
102		CONNACK: 2,
103		PUBLISH: 3,
104		PUBACK: 4,
105		PUBREC: 5,
106		PUBREL: 6,
107		PUBCOMP: 7,
108		SUBSCRIBE: 8,
109		SUBACK: 9,
110		UNSUBSCRIBE: 10,
111		UNSUBACK: 11,
112		PINGREQ: 12,
113		PINGRESP: 13,
114		DISCONNECT: 14
115	};
116
117	// Collection of utility methods used to simplify module code 
118	// and promote the DRY pattern.  
119
120	/**
121	 * Validate an object's parameter names to ensure they
122	 * match a list of expected variables name for this option
123	 * type. Used to ensure option object passed into the API don't
124	 * contain erroneous parameters.
125	 * @param {Object} obj - User options object
126	 * @param {Object} keys - valid keys and types that may exist in obj.
127	 * @throws {Error} Invalid option parameter found.
128	 * @private
129	 */
130	var validate = function(obj, keys) {
131		for (var key in obj) {
132			if (obj.hasOwnProperty(key)) {
133				if (keys.hasOwnProperty(key)) {
134					if (typeof obj[key] !== keys[key])
135					   throw new Error(format(ERROR.INVALID_TYPE, [typeof obj[key], key]));
136				} else {
137					var errorStr = "Unknown property, " + key + ". Valid properties are:";
138					for (var key in keys)
139						if (keys.hasOwnProperty(key))
140							errorStr = errorStr+" "+key;
141					throw new Error(errorStr);
142				}
143			}
144		}
145	};
146
147	/**
148	 * Return a new function which runs the user function bound
149	 * to a fixed scope.
150	 * @param {function} User function
151	 * @param {object} Function scope
152	 * @return {function} User function bound to another scope
153	 * @private
154	 */
155	var scope = function (f, scope) {
156		return function () {
157			return f.apply(scope, arguments);
158		};
159	};
160
161	/**
162	 * Unique message type identifiers, with associated
163	 * associated integer values.
164	 * @private
165	 */
166	var ERROR = {
167		OK: {code:0, text:"AMQJSC0000I OK."},
168		CONNECT_TIMEOUT: {code:1, text:"AMQJSC0001E Connect timed out."},
169		SUBSCRIBE_TIMEOUT: {code:2, text:"AMQJS0002E Subscribe timed out."},
170		UNSUBSCRIBE_TIMEOUT: {code:3, text:"AMQJS0003E Unsubscribe timed out."},
171		PING_TIMEOUT: {code:4, text:"AMQJS0004E Ping timed out."},
172		INTERNAL_ERROR: {code:5, text:"AMQJS0005E Internal error. Error Message: {0}, Stack trace: {1}"},
173		CONNACK_RETURNCODE: {code:6, text:"AMQJS0006E Bad Connack return code:{0} {1}."},
174		SOCKET_ERROR: {code:7, text:"AMQJS0007E Socket error:{0}."},
175		SOCKET_CLOSE: {code:8, text:"AMQJS0008I Socket closed."},
176		MALFORMED_UTF: {code:9, text:"AMQJS0009E Malformed UTF data:{0} {1} {2}."},
177		UNSUPPORTED: {code:10, text:"AMQJS0010E {0} is not supported by this browser."},
178		INVALID_STATE: {code:11, text:"AMQJS0011E Invalid state {0}."},
179		INVALID_TYPE: {code:12, text:"AMQJS0012E Invalid type {0} for {1}."},
180		INVALID_ARGUMENT: {code:13, text:"AMQJS0013E Invalid argument {0} for {1}."},
181		UNSUPPORTED_OPERATION: {code:14, text:"AMQJS0014E Unsupported operation."},
182		INVALID_STORED_DATA: {code:15, text:"AMQJS0015E Invalid data in local storage key={0} value={1}."},
183		INVALID_MQTT_MESSAGE_TYPE: {code:16, text:"AMQJS0016E Invalid MQTT message type {0}."},
184		MALFORMED_UNICODE: {code:17, text:"AMQJS0017E Malformed Unicode string:{0} {1}."},
185	};
186
187	/** CONNACK RC Meaning. */
188	var CONNACK_RC = {
189		0:"Connection Accepted",
190		1:"Connection Refused: unacceptable protocol version",
191		2:"Connection Refused: identifier rejected",
192		3:"Connection Refused: server unavailable",
193		4:"Connection Refused: bad user name or password",
194		5:"Connection Refused: not authorized"
195	};
196
197	/**
198	 * Format an error message text.
199	 * @private
200	 * @param {error} ERROR.KEY value above.
201	 * @param {substitutions} [array] substituted into the text.
202	 * @return the text with the substitutions made.
203	 */
204	var format = function(error, substitutions) {
205		var text = error.text;
206		if (substitutions) {
207		  var field,start;
208		  for (var i=0; i<substitutions.length; i++) {
209			field = "{"+i+"}";
210			start = text.indexOf(field);
211			if(start > 0) {
212				var part1 = text.substring(0,start);
213				var part2 = text.substring(start+field.length);
214				text = part1+substitutions[i]+part2;
215			}
216		  }
217		}
218		return text;
219	};
220
221	//MQTT protocol and version          6    M    Q    I    s    d    p    3
222	var MqttProtoIdentifierv3 = [0x00,0x06,0x4d,0x51,0x49,0x73,0x64,0x70,0x03];
223	//MQTT proto/version for 311         4    M    Q    T    T    4
224	var MqttProtoIdentifierv4 = [0x00,0x04,0x4d,0x51,0x54,0x54,0x04];
225
226	/**
227	 * Construct an MQTT wire protocol message.
228	 * @param type MQTT packet type.
229	 * @param options optional wire message attributes.
230	 *
231	 * Optional properties
232	 *
233	 * messageIdentifier: message ID in the range [0..65535]
234	 * payloadMessage:	Application Message - PUBLISH only
235	 * connectStrings:	array of 0 or more Strings to be put into the CONNECT payload
236	 * topics:			array of strings (SUBSCRIBE, UNSUBSCRIBE)
237	 * requestQoS:		array of QoS values [0..2]
238	 *
239	 * "Flag" properties
240	 * cleanSession:	true if present / false if absent (CONNECT)
241	 * willMessage:  	true if present / false if absent (CONNECT)
242	 * isRetained:		true if present / false if absent (CONNECT)
243	 * userName:		true if present / false if absent (CONNECT)
244	 * password:		true if present / false if absent (CONNECT)
245	 * keepAliveInterval:	integer [0..65535]  (CONNECT)
246	 *
247	 * @private
248	 * @ignore
249	 */
250	var WireMessage = function (type, options) {
251		this.type = type;
252		for (var name in options) {
253			if (options.hasOwnProperty(name)) {
254				this[name] = options[name];
255			}
256		}
257	};
258
259	WireMessage.prototype.encode = function() {
260		// Compute the first byte of the fixed header
261		var first = ((this.type & 0x0f) << 4);
262
263		/*
264		 * Now calculate the length of the variable header + payload by adding up the lengths
265		 * of all the component parts
266		 */
267
268		var remLength = 0;
269		var topicStrLength = new Array();
270		var destinationNameLength = 0;
271
272		// if the message contains a messageIdentifier then we need two bytes for that
273		if (this.messageIdentifier != undefined)
274			remLength += 2;
275
276		switch(this.type) {
277			// If this a Connect then we need to include 12 bytes for its header
278			case MESSAGE_TYPE.CONNECT:
279				switch(this.mqttVersion) {
280					case 3:
281						remLength += MqttProtoIdentifierv3.length + 3;
282						break;
283					case 4:
284						remLength += MqttProtoIdentifierv4.length + 3;
285						break;
286				}
287
288				remLength += UTF8Length(this.clientId) + 2;
289				if (this.willMessage != undefined) {
290					remLength += UTF8Length(this.willMessage.destinationName) + 2;
291					// Will message is always a string, sent as UTF-8 characters with a preceding length.
292					var willMessagePayloadBytes = this.willMessage.payloadBytes;
293					if (!(willMessagePayloadBytes instanceof Uint8Array))
294						willMessagePayloadBytes = new Uint8Array(payloadBytes);
295					remLength += willMessagePayloadBytes.byteLength +2;
296				}
297				if (this.userName != undefined)
298					remLength += UTF8Length(this.userName) + 2;
299				if (this.password != undefined)
300					remLength += UTF8Length(this.password) + 2;
301			break;
302
303			// Subscribe, Unsubscribe can both contain topic strings
304			case MESSAGE_TYPE.SUBSCRIBE:
305				first |= 0x02; // Qos = 1;
306				for ( var i = 0; i < this.topics.length; i++) {
307					topicStrLength[i] = UTF8Length(this.topics[i]);
308					remLength += topicStrLength[i] + 2;
309				}
310				remLength += this.requestedQos.length; // 1 byte for each topic's Qos
311				// QoS on Subscribe only
312				break;
313
314			case MESSAGE_TYPE.UNSUBSCRIBE:
315				first |= 0x02; // Qos = 1;
316				for ( var i = 0; i < this.topics.length; i++) {
317					topicStrLength[i] = UTF8Length(this.topics[i]);
318					remLength += topicStrLength[i] + 2;
319				}
320				break;
321
322			case MESSAGE_TYPE.PUBREL:
323				first |= 0x02; // Qos = 1;
324				break;
325
326			case MESSAGE_TYPE.PUBLISH:
327				if (this.payloadMessage.duplicate) first |= 0x08;
328				first  = first |= (this.payloadMessage.qos << 1);
329				if (this.payloadMessage.retained) first |= 0x01;
330				destinationNameLength = UTF8Length(this.payloadMessage.destinationName);
331				remLength += destinationNameLength + 2;
332				var payloadBytes = this.payloadMessage.payloadBytes;
333				remLength += payloadBytes.byteLength;
334				if (payloadBytes instanceof ArrayBuffer)
335					payloadBytes = new Uint8Array(payloadBytes);
336				else if (!(payloadBytes instanceof Uint8Array))
337					payloadBytes = new Uint8Array(payloadBytes.buffer);
338				break;
339
340			case MESSAGE_TYPE.DISCONNECT:
341				break;
342
343			default:
344				;
345		}
346
347		// Now we can allocate a buffer for the message
348
349		var mbi = encodeMBI(remLength);  // Convert the length to MQTT MBI format
350		var pos = mbi.length + 1;        // Offset of start of variable header
351		var buffer = new ArrayBuffer(remLength + pos);
352		var byteStream = new Uint8Array(buffer);    // view it as a sequence of bytes
353
354		//Write the fixed header into the buffer
355		byteStream[0] = first;
356		byteStream.set(mbi,1);
357
358		// If this is a PUBLISH then the variable header starts with a topic
359		if (this.type == MESSAGE_TYPE.PUBLISH)
360			pos = writeString(this.payloadMessage.destinationName, destinationNameLength, byteStream, pos);
361		// If this is a CONNECT then the variable header contains the protocol name/version, flags and keepalive time
362
363		else if (this.type == MESSAGE_TYPE.CONNECT) {
364			switch (this.mqttVersion) {
365				case 3:
366					byteStream.set(MqttProtoIdentifierv3, pos);
367					pos += MqttProtoIdentifierv3.length;
368					break;
369				case 4:
370					byteStream.set(MqttProtoIdentifierv4, pos);
371					pos += MqttProtoIdentifierv4.length;
372					break;
373			}
374			var connectFlags = 0;
375			if (this.cleanSession)
376				connectFlags = 0x02;
377			if (this.willMessage != undefined ) {
378				connectFlags |= 0x04;
379				connectFlags |= (this.willMessage.qos<<3);
380				if (this.willMessage.retained) {
381					connectFlags |= 0x20;
382				}
383			}
384			if (this.userName != undefined)
385				connectFlags |= 0x80;
386			if (this.password != undefined)
387				connectFlags |= 0x40;
388			byteStream[pos++] = connectFlags;
389			pos = writeUint16 (this.keepAliveInterval, byteStream, pos);
390		}
391
392		// Output the messageIdentifier - if there is one
393		if (this.messageIdentifier != undefined)
394			pos = writeUint16 (this.messageIdentifier, byteStream, pos);
395
396		switch(this.type) {
397			case MESSAGE_TYPE.CONNECT:
398				pos = writeString(this.clientId, UTF8Length(this.clientId), byteStream, pos);
399				if (this.willMessage != undefined) {
400					pos = writeString(this.willMessage.destinationName, UTF8Length(this.willMessage.destinationName), byteStream, pos);
401					pos = writeUint16(willMessagePayloadBytes.byteLength, byteStream, pos);
402					byteStream.set(willMessagePayloadBytes, pos);
403					pos += willMessagePayloadBytes.byteLength;
404
405				}
406			if (this.userName != undefined)
407				pos = writeString(this.userName, UTF8Length(this.userName), byteStream, pos);
408			if (this.password != undefined)
409				pos = writeString(this.password, UTF8Length(this.password), byteStream, pos);
410			break;
411
412			case MESSAGE_TYPE.PUBLISH:
413				// PUBLISH has a text or binary payload, if text do not add a 2 byte length field, just the UTF characters.	
414				byteStream.set(payloadBytes, pos);
415
416				break;
417
418//    	    case MESSAGE_TYPE.PUBREC:	
419//    	    case MESSAGE_TYPE.PUBREL:	
420//    	    case MESSAGE_TYPE.PUBCOMP:	
421//    	    	break;
422
423			case MESSAGE_TYPE.SUBSCRIBE:
424				// SUBSCRIBE has a list of topic strings and request QoS
425				for (var i=0; i<this.topics.length; i++) {
426					pos = writeString(this.topics[i], topicStrLength[i], byteStream, pos);
427					byteStream[pos++] = this.requestedQos[i];
428				}
429				break;
430
431			case MESSAGE_TYPE.UNSUBSCRIBE:
432				// UNSUBSCRIBE has a list of topic strings
433				for (var i=0; i<this.topics.length; i++)
434					pos = writeString(this.topics[i], topicStrLength[i], byteStream, pos);
435				break;
436
437			default:
438				// Do nothing.
439		}
440
441		return buffer;
442	}
443
444	function decodeMessage(input,pos) {
445	    var startingPos = pos;
446		var first = input[pos];
447		var type = first >> 4;
448		var messageInfo = first &= 0x0f;
449		pos += 1;
450
451
452		// Decode the remaining length (MBI format)
453
454		var digit;
455		var remLength = 0;
456		var multiplier = 1;
457		do {
458			if (pos == input.length) {
459			    return [null,startingPos];
460			}
461			digit = input[pos++];
462			remLength += ((digit & 0x7F) * multiplier);
463			multiplier *= 128;
464		} while ((digit & 0x80) != 0);
465
466		var endPos = pos+remLength;
467		if (endPos > input.length) {
468		    return [null,startingPos];
469		}
470
471		var wireMessage = new WireMessage(type);
472		switch(type) {
473			case MESSAGE_TYPE.CONNACK:
474				var connectAcknowledgeFlags = input[pos++];
475				if (connectAcknowledgeFlags & 0x01)
476					wireMessage.sessionPresent = true;
477				wireMessage.returnCode = input[pos++];
478				break;
479
480			case MESSAGE_TYPE.PUBLISH:
481				var qos = (messageInfo >> 1) & 0x03;
482
483				var len = readUint16(input, pos);
484				pos += 2;
485				var topicName = parseUTF8(input, pos, len);
486				pos += len;
487				// If QoS 1 or 2 there will be a messageIdentifier
488				if (qos > 0) {
489					wireMessage.messageIdentifier = readUint16(input, pos);
490					pos += 2;
491				}
492
493				var message = new Paho.MQTT.Message(input.subarray(pos, endPos));
494				if ((messageInfo & 0x01) == 0x01)
495					message.retained = true;
496				if ((messageInfo & 0x08) == 0x08)
497					message.duplicate =  true;
498				message.qos = qos;
499				message.destinationName = topicName;
500				wireMessage.payloadMessage = message;
501				break;
502
503			case  MESSAGE_TYPE.PUBACK:
504			case  MESSAGE_TYPE.PUBREC:
505			case  MESSAGE_TYPE.PUBREL:
506			case  MESSAGE_TYPE.PUBCOMP:
507			case  MESSAGE_TYPE.UNSUBACK:
508				wireMessage.messageIdentifier = readUint16(input, pos);
509				break;
510
511			case  MESSAGE_TYPE.SUBACK:
512				wireMessage.messageIdentifier = readUint16(input, pos);
513				pos += 2;
514				wireMessage.returnCode = input.subarray(pos, endPos);
515				break;
516
517			default:
518				;
519		}
520
521		return [wireMessage,endPos];
522	}
523
524	function writeUint16(input, buffer, offset) {
525		buffer[offset++] = input >> 8;      //MSB
526		buffer[offset++] = input % 256;     //LSB 
527		return offset;
528	}
529
530	function writeString(input, utf8Length, buffer, offset) {
531		offset = writeUint16(utf8Length, buffer, offset);
532		stringToUTF8(input, buffer, offset);
533		return offset + utf8Length;
534	}
535
536	function readUint16(buffer, offset) {
537		return 256*buffer[offset] + buffer[offset+1];
538	}
539
540	/**
541	 * Encodes an MQTT Multi-Byte Integer
542	 * @private
543	 */
544	function encodeMBI(number) {
545		var output = new Array(1);
546		var numBytes = 0;
547
548		do {
549			var digit = number % 128;
550			number = number >> 7;
551			if (number > 0) {
552				digit |= 0x80;
553			}
554			output[numBytes++] = digit;
555		} while ( (number > 0) && (numBytes<4) );
556
557		return output;
558	}
559
560	/**
561	 * Takes a String and calculates its length in bytes when encoded in UTF8.
562	 * @private
563	 */
564	function UTF8Length(input) {
565		var output = 0;
566		for (var i = 0; i<input.length; i++)
567		{
568			var charCode = input.charCodeAt(i);
569				if (charCode > 0x7FF)
570				   {
571					  // Surrogate pair means its a 4 byte character
572					  if (0xD800 <= charCode && charCode <= 0xDBFF)
573						{
574						  i++;
575						  output++;
576						}
577				   output +=3;
578				   }
579			else if (charCode > 0x7F)
580				output +=2;
581			else
582				output++;
583		}
584		return output;
585	}
586
587	/**
588	 * Takes a String and writes it into an array as UTF8 encoded bytes.
589	 * @private
590	 */
591	function stringToUTF8(input, output, start) {
592		var pos = start;
593		for (var i = 0; i<input.length; i++) {
594			var charCode = input.charCodeAt(i);
595
596			// Check for a surrogate pair.
597			if (0xD800 <= charCode && charCode <= 0xDBFF) {
598				var lowCharCode = input.charCodeAt(++i);
599				if (isNaN(lowCharCode)) {
600					throw new Error(format(ERROR.MALFORMED_UNICODE, [charCode, lowCharCode]));
601				}
602				charCode = ((charCode - 0xD800)<<10) + (lowCharCode - 0xDC00) + 0x10000;
603
604			}
605
606			if (charCode <= 0x7F) {
607				output[pos++] = charCode;
608			} else if (charCode <= 0x7FF) {
609				output[pos++] = charCode>>6  & 0x1F | 0xC0;
610				output[pos++] = charCode     & 0x3F | 0x80;
611			} else if (charCode <= 0xFFFF) {
612				output[pos++] = charCode>>12 & 0x0F | 0xE0;
613				output[pos++] = charCode>>6  & 0x3F | 0x80;
614				output[pos++] = charCode     & 0x3F | 0x80;
615			} else {
616				output[pos++] = charCode>>18 & 0x07 | 0xF0;
617				output[pos++] = charCode>>12 & 0x3F | 0x80;
618				output[pos++] = charCode>>6  & 0x3F | 0x80;
619				output[pos++] = charCode     & 0x3F | 0x80;
620			};
621		}
622		return output;
623	}
624
625	function parseUTF8(input, offset, length) {
626		var output = "";
627		var utf16;
628		var pos = offset;
629
630		while (pos < offset+length)
631		{
632			var byte1 = input[pos++];
633			if (byte1 < 128)
634				utf16 = byte1;
635			else
636			{
637				var byte2 = input[pos++]-128;
638				if (byte2 < 0)
639					throw new Error(format(ERROR.MALFORMED_UTF, [byte1.toString(16), byte2.toString(16),""]));
640				if (byte1 < 0xE0)             // 2 byte character
641					utf16 = 64*(byte1-0xC0) + byte2;
642				else
643				{
644					var byte3 = input[pos++]-128;
645					if (byte3 < 0)
646						throw new Error(format(ERROR.MALFORMED_UTF, [byte1.toString(16), byte2.toString(16), byte3.toString(16)]));
647					if (byte1 < 0xF0)        // 3 byte character
648						utf16 = 4096*(byte1-0xE0) + 64*byte2 + byte3;
649								else
650								{
651								   var byte4 = input[pos++]-128;
652								   if (byte4 < 0)
653						throw new Error(format(ERROR.MALFORMED_UTF, [byte1.toString(16), byte2.toString(16), byte3.toString(16), byte4.toString(16)]));
654								   if (byte1 < 0xF8)        // 4 byte character
655										   utf16 = 262144*(byte1-0xF0) + 4096*byte2 + 64*byte3 + byte4;
656					   else                     // longer encodings are not supported
657						throw new Error(format(ERROR.MALFORMED_UTF, [byte1.toString(16), byte2.toString(16), byte3.toString(16), byte4.toString(16)]));
658								}
659				}
660			}
661
662				if (utf16 > 0xFFFF)   // 4 byte character - express as a surrogate pair
663				  {
664					 utf16 -= 0x10000;
665					 output += String.fromCharCode(0xD800 + (utf16 >> 10)); // lead character
666					 utf16 = 0xDC00 + (utf16 & 0x3FF);  // trail character
667				  }
668			output += String.fromCharCode(utf16);
669		}
670		return output;
671	}
672
673	/**
674	 * Repeat keepalive requests, monitor responses.
675	 * @ignore
676	 */
677	var Pinger = function(client, window, keepAliveInterval) {
678		this._client = client;
679		this._window = window;
680		this._keepAliveInterval = keepAliveInterval*1000;
681		this.isReset = false;
682
683		var pingReq = new WireMessage(MESSAGE_TYPE.PINGREQ).encode();
684
685		var doTimeout = function (pinger) {
686			return function () {
687				return doPing.apply(pinger);
688			};
689		};
690
691		/** @ignore */
692		var doPing = function() {
693			if (!this.isReset) {
694				this._client._trace("Pinger.doPing", "Timed out");
695				this._client._disconnected( ERROR.PING_TIMEOUT.code , format(ERROR.PING_TIMEOUT));
696			} else {
697				this.isReset = false;
698				this._client._trace("Pinger.doPing", "send PINGREQ");
699				this._client.socket.send(pingReq);
700				this.timeout = this._window.setTimeout(doTimeout(this), this._keepAliveInterval);
701			}
702		}
703
704		this.reset = function() {
705			this.isReset = true;
706			this._window.clearTimeout(this.timeout);
707			if (this._keepAliveInterval > 0)
708				this.timeout = setTimeout(doTimeout(this), this._keepAliveInterval);
709		}
710
711		this.cancel = function() {
712			this._window.clearTimeout(this.timeout);
713		}
714	 };
715
716	/**
717	 * Monitor request completion.
718	 * @ignore
719	 */
720	var Timeout = function(client, window, timeoutSeconds, action, args) {
721		this._window = window;
722		if (!timeoutSeconds)
723			timeoutSeconds = 30;
724
725		var doTimeout = function (action, client, args) {
726			return function () {
727				return action.apply(client, args);
728			};
729		};
730		this.timeout = setTimeout(doTimeout(action, client, args), timeoutSeconds * 1000);
731
732		this.cancel = function() {
733			this._window.clearTimeout(this.timeout);
734		}
735	};
736
737	/*
738	 * Internal implementation of the Websockets MQTT V3.1 client.
739	 * 
740	 * @name Paho.MQTT.ClientImpl @constructor 
741	 * @param {String} host the DNS nameof the webSocket host. 
742	 * @param {Number} port the port number for that host.
743	 * @param {String} clientId the MQ client identifier.
744	 */
745	var ClientImpl = function (uri, host, port, path, clientId) {
746		// Check dependencies are satisfied in this browser.
747		if (!("WebSocket" in global && global["WebSocket"] !== null)) {
748			throw new Error(format(ERROR.UNSUPPORTED, ["WebSocket"]));
749		}
750		if (!("localStorage" in global && global["localStorage"] !== null)) {
751			throw new Error(format(ERROR.UNSUPPORTED, ["localStorage"]));
752		}
753		if (!("ArrayBuffer" in global && global["ArrayBuffer"] !== null)) {
754			throw new Error(format(ERROR.UNSUPPORTED, ["ArrayBuffer"]));
755		}
756		this._trace("Paho.MQTT.Client", uri, host, port, path, clientId);
757
758		this.host = host;
759		this.port = port;
760		this.path = path;
761		this.uri = uri;
762		this.clientId = clientId;
763
764		// Local storagekeys are qualified with the following string.
765		// The conditional inclusion of path in the key is for backward
766		// compatibility to when the path was not configurable and assumed to
767		// be /mqtt
768		this._localKey=host+":"+port+(path!="/mqtt"?":"+path:"")+":"+clientId+":";
769
770		// Create private instance-only message queue
771		// Internal queue of messages to be sent, in sending order. 
772		this._msg_queue = [];
773
774		// Messages we have sent and are expecting a response for, indexed by their respective message ids. 
775		this._sentMessages = {};
776
777		// Messages we have received and acknowleged and are expecting a confirm message for
778		// indexed by their respective message ids. 
779		this._receivedMessages = {};
780
781		// Internal list of callbacks to be executed when messages
782		// have been successfully sent over web socket, e.g. disconnect
783		// when it doesn't have to wait for ACK, just message is dispatched.
784		this._notify_msg_sent = {};
785
786		// Unique identifier for SEND messages, incrementing
787		// counter as messages are sent.
788		this._message_identifier = 1;
789
790		// Used to determine the transmission sequence of stored sent messages.
791		this._sequence = 0;
792
793
794		// Load the local state, if any, from the saved version, only restore state relevant to this client.   	
795		for (var key in localStorage)
796			if (   key.indexOf("Sent:"+this._localKey) == 0
797				|| key.indexOf("Received:"+this._localKey) == 0)
798			this.restore(key);
799	};
800
801	// Messaging Client public instance members. 
802	ClientImpl.prototype.host;
803	ClientImpl.prototype.port;
804	ClientImpl.prototype.path;
805	ClientImpl.prototype.uri;
806	ClientImpl.prototype.clientId;
807
808	// Messaging Client private instance members.
809	ClientImpl.prototype.socket;
810	/* true once we have received an acknowledgement to a CONNECT packet. */
811	ClientImpl.prototype.connected = false;
812	/* The largest message identifier allowed, may not be larger than 2**16 but 
813	 * if set smaller reduces the maximum number of outbound messages allowed.
814	 */
815	ClientImpl.prototype.maxMessageIdentifier = 65536;
816	ClientImpl.prototype.connectOptions;
817	ClientImpl.prototype.hostIndex;
818	ClientImpl.prototype.onConnectionLost;
819	ClientImpl.prototype.onMessageDelivered;
820	ClientImpl.prototype.onMessageArrived;
821	ClientImpl.prototype.traceFunction;
822	ClientImpl.prototype._msg_queue = null;
823	ClientImpl.prototype._connectTimeout;
824	/* The sendPinger monitors how long we allow before we send data to prove to the server that we are alive. */
825	ClientImpl.prototype.sendPinger = null;
826	/* The receivePinger monitors how long we allow before we require evidence that the server is alive. */
827	ClientImpl.prototype.receivePinger = null;
828
829	ClientImpl.prototype.receiveBuffer = null;
830
831	ClientImpl.prototype._traceBuffer = null;
832	ClientImpl.prototype._MAX_TRACE_ENTRIES = 100;
833
834	ClientImpl.prototype.connect = function (connectOptions) {
835		var connectOptionsMasked = this._traceMask(connectOptions, "password");
836		this._trace("Client.connect", connectOptionsMasked, this.socket, this.connected);
837
838		if (this.connected)
839			throw new Error(format(ERROR.INVALID_STATE, ["already connected"]));
840		if (this.socket)
841			throw new Error(format(ERROR.INVALID_STATE, ["already connected"]));
842
843		this.connectOptions = connectOptions;
844
845		if (connectOptions.uris) {
846			this.hostIndex = 0;
847			this._doConnect(connectOptions.uris[0]);
848		} else {
849			this._doConnect(this.uri);
850		}
851
852	};
853
854	ClientImpl.prototype.subscribe = function (filter, subscribeOptions) {
855		this._trace("Client.subscribe", filter, subscribeOptions);
856
857		if (!this.connected)
858			throw new Error(format(ERROR.INVALID_STATE, ["not connected"]));
859
860		var wireMessage = new WireMessage(MESSAGE_TYPE.SUBSCRIBE);
861		wireMessage.topics=[filter];
862		if (subscribeOptions.qos != undefined)
863			wireMessage.requestedQos = [subscribeOptions.qos];
864		else
865			wireMessage.requestedQos = [0];
866
867		if (subscribeOptions.onSuccess) {
868			wireMessage.onSuccess = function(grantedQos) {subscribeOptions.onSuccess({invocationContext:subscribeOptions.invocationContext,grantedQos:grantedQos});};
869		}
870
871		if (subscribeOptions.onFailure) {
872			wireMessage.onFailure = function(errorCode) {subscribeOptions.onFailure({invocationContext:subscribeOptions.invocationContext,errorCode:errorCode});};
873		}
874
875		if (subscribeOptions.timeout) {
876			wireMessage.timeOut = new Timeout(this, window, subscribeOptions.timeout, subscribeOptions.onFailure
877					, [{invocationContext:subscribeOptions.invocationContext,
878						errorCode:ERROR.SUBSCRIBE_TIMEOUT.code,
879						errorMessage:format(ERROR.SUBSCRIBE_TIMEOUT)}]);
880		}
881
882		// All subscriptions return a SUBACK. 
883		this._requires_ack(wireMessage);
884		this._schedule_message(wireMessage);
885	};
886
887	/** @ignore */
888	ClientImpl.prototype.unsubscribe = function(filter, unsubscribeOptions) {
889		this._trace("Client.unsubscribe", filter, unsubscribeOptions);
890
891		if (!this.connected)
892		   throw new Error(format(ERROR.INVALID_STATE, ["not connected"]));
893
894		var wireMessage = new WireMessage(MESSAGE_TYPE.UNSUBSCRIBE);
895		wireMessage.topics = [filter];
896
897		if (unsubscribeOptions.onSuccess) {
898			wireMessage.callback = function() {unsubscribeOptions.onSuccess({invocationContext:unsubscribeOptions.invocationContext});};
899		}
900		if (unsubscribeOptions.timeout) {
901			wireMessage.timeOut = new Timeout(this, window, unsubscribeOptions.timeout, unsubscribeOptions.onFailure
902					, [{invocationContext:unsubscribeOptions.invocationContext,
903						errorCode:ERROR.UNSUBSCRIBE_TIMEOUT.code,
904						errorMessage:format(ERROR.UNSUBSCRIBE_TIMEOUT)}]);
905		}
906
907		// All unsubscribes return a SUBACK.         
908		this._requires_ack(wireMessage);
909		this._schedule_message(wireMessage);
910	};
911
912	ClientImpl.prototype.send = function (message) {
913		this._trace("Client.send", message);
914
915		if (!this.connected)
916		   throw new Error(format(ERROR.INVALID_STATE, ["not connected"]));
917
918		wireMessage = new WireMessage(MESSAGE_TYPE.PUBLISH);
919		wireMessage.payloadMessage = message;
920
921		if (message.qos > 0)
922			this._requires_ack(wireMessage);
923		else if (this.onMessageDelivered)
924			this._notify_msg_sent[wireMessage] = this.onMessageDelivered(wireMessage.payloadMessage);
925		this._schedule_message(wireMessage);
926	};
927
928	ClientImpl.prototype.disconnect = function () {
929		this._trace("Client.disconnect");
930
931		if (!this.socket)
932			throw new Error(format(ERROR.INVALID_STATE, ["not connecting or connected"]));
933
934		wireMessage = new WireMessage(MESSAGE_TYPE.DISCONNECT);
935
936		// Run the disconnected call back as soon as the message has been sent,
937		// in case of a failure later on in the disconnect processing.
938		// as a consequence, the _disconected call back may be run several times.
939		this._notify_msg_sent[wireMessage] = scope(this._disconnected, this);
940
941		this._schedule_message(wireMessage);
942	};
943
944	ClientImpl.prototype.getTraceLog = function () {
945		if ( this._traceBuffer !== null ) {
946			this._trace("Client.getTraceLog", new Date());
947			this._trace("Client.getTraceLog in flight messages", this._sentMessages.length);
948			for (var key in this._sentMessages)
949				this._trace("_sentMessages ",key, this._sentMessages[key]);
950			for (var key in this._receivedMessages)
951				this._trace("_receivedMessages ",key, this._receivedMessages[key]);
952
953			return this._traceBuffer;
954		}
955	};
956
957	ClientImpl.prototype.startTrace = function () {
958		if ( this._traceBuffer === null ) {
959			this._traceBuffer = [];
960		}
961		this._trace("Client.startTrace", new Date(), version);
962	};
963
964	ClientImpl.prototype.stopTrace = function () {
965		delete this._traceBuffer;
966	};
967
968	ClientImpl.prototype._doConnect = function (wsurl) {
969		// When the socket is open, this client will send the CONNECT WireMessage using the saved parameters. 
970		if (this.connectOptions.useSSL) {
971		    var uriParts = wsurl.split(":");
972		    uriParts[0] = "wss";
973		    wsurl = uriParts.join(":");
974		}
975		this.connected = false;
976		if (this.connectOptions.mqttVersion < 4) {
977			this.socket = new WebSocket(wsurl, ["mqttv3.1"]);
978		} else {
979			this.socket = new WebSocket(wsurl, ["mqtt"]);
980		}
981		this.socket.binaryType = 'arraybuffer';
982
983		this.socket.onopen = scope(this._on_socket_open, this);
984		this.socket.onmessage = scope(this._on_socket_message, this);
985		this.socket.onerror = scope(this._on_socket_error, this);
986		this.socket.onclose = scope(this._on_socket_close, this);
987
988		this.sendPinger = new Pinger(this, window, this.connectOptions.keepAliveInterval);
989		this.receivePinger = new Pinger(this, window, this.connectOptions.keepAliveInterval);
990
991		this._connectTimeout = new Timeout(this, window, this.connectOptions.timeout, this._disconnected,  [ERROR.CONNECT_TIMEOUT.code, format(ERROR.CONNECT_TIMEOUT)]);
992	};
993
994
995	// Schedule a new message to be sent over the WebSockets
996	// connection. CONNECT messages cause WebSocket connection
997	// to be started. All other messages are queued internally
998	// until this has happened. When WS connection starts, process
999	// all outstanding messages. 
1000	ClientImpl.prototype._schedule_message = function (message) {
1001		this._msg_queue.push(message);
1002		// Process outstanding messages in the queue if we have an  open socket, and have received CONNACK. 
1003		if (this.connected) {
1004			this._process_queue();
1005		}
1006	};
1007
1008	ClientImpl.prototype.store = function(prefix, wireMessage) {
1009		var storedMessage = {type:wireMessage.type, messageIdentifier:wireMessage.messageIdentifier, version:1};
1010
1011		switch(wireMessage.type) {
1012		  case MESSAGE_TYPE.PUBLISH:
1013			  if(wireMessage.pubRecReceived)
1014				  storedMessage.pubRecReceived = true;
1015
1016			  // Convert the payload to a hex string.
1017			  storedMessage.payloadMessage = {};
1018			  var hex = "";
1019			  var messageBytes = wireMessage.payloadMessage.payloadBytes;
1020			  for (var i=0; i<messageBytes.length; i++) {
1021				if (messageBytes[i] <= 0xF)
1022				  hex = hex+"0"+messageBytes[i].toString(16);
1023				else
1024				  hex = hex+messageBytes[i].toString(16);
1025			  }
1026			  storedMessage.payloadMessage.payloadHex = hex;
1027
1028			  storedMessage.payloadMessage.qos = wireMessage.payloadMessage.qos;
1029			  storedMessage.payloadMessage.destinationName = wireMessage.payloadMessage.destinationName;
1030			  if (wireMessage.payloadMessage.duplicate)
1031				  storedMessage.payloadMessage.duplicate = true;
1032			  if (wireMessage.payloadMessage.retained)
1033				  storedMessage.payloadMessage.retained = true;
1034
1035			  // Add a sequence number to sent messages.
1036			  if ( prefix.indexOf("Sent:") == 0 ) {
1037				  if ( wireMessage.sequence === undefined )
1038					  wireMessage.sequence = ++this._sequence;
1039				  storedMessage.sequence = wireMessage.sequence;
1040			  }
1041			  break;
1042
1043			default:
1044				throw Error(format(ERROR.INVALID_STORED_DATA, [key, storedMessage]));
1045		}
1046		localStorage.setItem(prefix+this._localKey+wireMessage.messageIdentifier, JSON.stringify(storedMessage));
1047	};
1048
1049	ClientImpl.prototype.restore = function(key) {
1050		var value = localStorage.getItem(key);
1051		var storedMessage = JSON.parse(value);
1052
1053		var wireMessage = new WireMessage(storedMessage.type, storedMessage);
1054
1055		switch(storedMessage.type) {
1056		  case MESSAGE_TYPE.PUBLISH:
1057			  // Replace the payload message with a Message object.
1058			  var hex = storedMessage.payloadMessage.payloadHex;
1059			  var buffer = new ArrayBuffer((hex.length)/2);
1060			  var byteStream = new Uint8Array(buffer);
1061			  var i = 0;
1062			  while (hex.length >= 2) {
1063				  var x = parseInt(hex.substring(0, 2), 16);
1064				  hex = hex.substring(2, hex.length);
1065				  byteStream[i++] = x;
1066			  }
1067			  var payloadMessage = new Paho.MQTT.Message(byteStream);
1068
1069			  payloadMessage.qos = storedMessage.payloadMessage.qos;
1070			  payloadMessage.destinationName = storedMessage.payloadMessage.destinationName;
1071			  if (storedMessage.payloadMessage.duplicate)
1072				  payloadMessage.duplicate = true;
1073			  if (storedMessage.payloadMessage.retained)
1074				  payloadMessage.retained = true;
1075			  wireMessage.payloadMessage = payloadMessage;
1076
1077			  break;
1078
1079			default:
1080			  throw Error(format(ERROR.INVALID_STORED_DATA, [key, value]));
1081		}
1082
1083		if (key.indexOf("Sent:"+this._localKey) == 0) {
1084			wireMessage.payloadMessage.duplicate = true;
1085			this._sentMessages[wireMessage.messageIdentifier] = wireMessage;
1086		} else if (key.indexOf("Received:"+this._localKey) == 0) {
1087			this._receivedMessages[wireMessage.messageIdentifier] = wireMessage;
1088		}
1089	};
1090
1091	ClientImpl.prototype._process_queue = function () {
1092		var message = null;
1093		// Process messages in order they were added
1094		var fifo = this._msg_queue.reverse();
1095
1096		// Send all queued messages down socket connection
1097		while ((message = fifo.pop())) {
1098			this._socket_send(message);
1099			// Notify listeners that message was successfully sent
1100			if (this._notify_msg_sent[message]) {
1101				this._notify_msg_sent[message]();
1102				delete this._notify_msg_sent[message];
1103			}
1104		}
1105	};
1106
1107	/**
1108	 * Expect an ACK response for this message. Add message to the set of in progress
1109	 * messages and set an unused identifier in this message.
1110	 * @ignore
1111	 */
1112	ClientImpl.prototype._requires_ack = function (wireMessage) {
1113		var messageCount = Object.keys(this._sentMessages).length;
1114		if (messageCount > this.maxMessageIdentifier)
1115			throw Error ("Too many messages:"+messageCount);
1116
1117		while(this._sentMessages[this._message_identifier] !== undefined) {
1118			this._message_identifier++;
1119		}
1120		wireMessage.messageIdentifier = this._message_identifier;
1121		this._sentMessages[wireMessage.messageIdentifier] = wireMessage;
1122		if (wireMessage.type === MESSAGE_TYPE.PUBLISH) {
1123			this.store("Sent:", wireMessage);
1124		}
1125		if (this._message_identifier === this.maxMessageIdentifier) {
1126			this._message_identifier = 1;
1127		}
1128	};
1129
1130	/**
1131	 * Called when the underlying websocket has been opened.
1132	 * @ignore
1133	 */
1134	ClientImpl.prototype._on_socket_open = function () {
1135		// Create the CONNECT message object.
1136		var wireMessage = new WireMessage(MESSAGE_TYPE.CONNECT, this.connectOptions);
1137		wireMessage.clientId = this.clientId;
1138		this._socket_send(wireMessage);
1139	};
1140
1141	/**
1142	 * Called when the underlying websocket has received a complete packet.
1143	 * @ignore
1144	 */
1145	ClientImpl.prototype._on_socket_message = function (event) {
1146		this._trace("Client._on_socket_message", event.data);
1147		// Reset the receive ping timer, we now have evidence the server is alive.
1148		this.receivePinger.reset();
1149		var messages = this._deframeMessages(event.data);
1150		for (var i = 0; i < messages.length; i+=1) {
1151		    this._handleMessage(messages[i]);
1152		}
1153	}
1154
1155	ClientImpl.prototype._deframeMessages = function(data) {
1156		var byteArray = new Uint8Array(data);
1157	    if (this.receiveBuffer) {
1158	        var newData = new Uint8Array(this.receiveBuffer.length+byteArray.length);
1159	        newData.set(this.receiveBuffer);
1160	        newData.set(byteArray,this.receiveBuffer.length);
1161	        byteArray = newData;
1162	        delete this.receiveBuffer;
1163	    }
1164		try {
1165		    var offset = 0;
1166		    var messages = [];
1167		    while(offset < byteArray.length) {
1168		        var result = decodeMessage(byteArray,offset);
1169		        var wireMessage = result[0];
1170		        offset = result[1];
1171		        if (wireMessage !== null) {
1172		            messages.push(wireMessage);
1173		        } else {
1174		            break;
1175		        }
1176		    }
1177		    if (offset < byteArray.length) {
1178		    	this.receiveBuffer = byteArray.subarray(offset);
1179		    }
1180		} catch (error) {
1181			this._disconnected(ERROR.INTERNAL_ERROR.code , format(ERROR.INTERNAL_ERROR, [error.message,error.stack.toString()]));
1182			return;
1183		}
1184		return messages;
1185	}
1186
1187	ClientImpl.prototype._handleMessage = function(wireMessage) {
1188
1189		this._trace("Client._handleMessage", wireMessage);
1190
1191		try {
1192			switch(wireMessage.type) {
1193			case MESSAGE_TYPE.CONNACK:
1194				this._connectTimeout.cancel();
1195
1196				// If we have started using clean session then clear up the local state.
1197				if (this.connectOptions.cleanSession) {
1198					for (var key in this._sentMessages) {
1199						var sentMessage = this._sentMessages[key];
1200						localStorage.removeItem("Sent:"+this._localKey+sentMessage.messageIdentifier);
1201					}
1202					this._sentMessages = {};
1203
1204					for (var key in this._receivedMessages) {
1205						var receivedMessage = this._receivedMessages[key];
1206						localStorage.removeItem("Received:"+this._localKey+receivedMessage.messageIdentifier);
1207					}
1208					this._receivedMessages = {};
1209				}
1210				// Client connected and ready for business.
1211				if (wireMessage.returnCode === 0) {
1212					this.connected = true;
1213					// Jump to the end of the list of uris and stop looking for a good host.
1214					if (this.connectOptions.uris)
1215						this.hostIndex = this.connectOptions.uris.length;
1216				} else {
1217					this._disconnected(ERROR.CONNACK_RETURNCODE.code , format(ERROR.CONNACK_RETURNCODE, [wireMessage.returnCode, CONNACK_RC[wireMessage.returnCode]]));
1218					break;
1219				}
1220
1221				// Resend messages.
1222				var sequencedMessages = new Array();
1223				for (var msgId in this._sentMessages) {
1224					if (this._sentMessages.hasOwnProperty(msgId))
1225						sequencedMessages.push(this._sentMessages[msgId]);
1226				}
1227
1228				// Sort sentMessages into the original sent order.
1229				var sequencedMessages = sequencedMessages.sort(function(a,b) {return a.sequence - b.sequence;} );
1230				for (var i=0, len=sequencedMessages.length; i<len; i++) {
1231					var sentMessage = sequencedMessages[i];
1232					if (sentMessage.type == MESSAGE_TYPE.PUBLISH && sentMessage.pubRecReceived) {
1233						var pubRelMessage = new WireMessage(MESSAGE_TYPE.PUBREL, {messageIdentifier:sentMessage.messageIdentifier});
1234						this._schedule_message(pubRelMessage);
1235					} else {
1236						this._schedule_message(sentMessage);
1237					};
1238				}
1239
1240				// Execute the connectOptions.onSuccess callback if there is one.
1241				if (this.connectOptions.onSuccess) {
1242					this.connectOptions.onSuccess({invocationContext:this.connectOptions.invocationContext});
1243				}
1244
1245				// Process all queued messages now that the connection is established.
1246				this._process_queue();
1247				break;
1248
1249			case MESSAGE_TYPE.PUBLISH:
1250				this._receivePublish(wireMessage);
1251				break;
1252
1253			case MESSAGE_TYPE.PUBACK:
1254				var sentMessage = this._sentMessages[wireMessage.messageIdentifier];
1255				 // If this is a re flow of a PUBACK after we have restarted receivedMessage will not exist.
1256				if (sentMessage) {
1257					delete this._sentMessages[wireMessage.messageIdentifier];
1258					localStorage.removeItem("Sent:"+this._localKey+wireMessage.messageIdentifier);
1259					if (this.onMessageDelivered)
1260						this.onMessageDelivered(sentMessage.payloadMessage);
1261				}
1262				break;
1263
1264			case MESSAGE_TYPE.PUBREC:
1265				var sentMessage = this._sentMessages[wireMessage.messageIdentifier];
1266				// If this is a re flow of a PUBREC after we have restarted receivedMessage will not exist.
1267				if (sentMessage) {
1268					sentMessage.pubRecReceived = true;
1269					var pubRelMessage = new WireMessage(MESSAGE_TYPE.PUBREL, {messageIdentifier:wireMessage.messageIdentifier});
1270					this.store("Sent:", sentMessage);
1271					this._schedule_message(pubRelMessage);
1272				}
1273				break;
1274
1275			case MESSAGE_TYPE.PUBREL:
1276				var receivedMessage = this._receivedMessages[wireMessage.messageIdentifier];
1277				localStorage.removeItem("Received:"+this._localKey+wireMessage.messageIdentifier);
1278				// If this is a re flow of a PUBREL after we have restarted receivedMessage will not exist.
1279				if (receivedMessage) {
1280					this._receiveMessage(receivedMessage);
1281					delete this._receivedMessages[wireMessage.messageIdentifier];
1282				}
1283				// Always flow PubComp, we may have previously flowed PubComp but the server lost it and restarted.
1284				var pubCompMessage = new WireMessage(MESSAGE_TYPE.PUBCOMP, {messageIdentifier:wireMessage.messageIdentifier});
1285				this._schedule_message(pubCompMessage);
1286				break;
1287
1288			case MESSAGE_TYPE.PUBCOMP:
1289				var sentMessage = this._sentMessages[wireMessage.messageIdentifier];
1290				delete this._sentMessages[wireMessage.messageIdentifier];
1291				localStorage.removeItem("Sent:"+this._localKey+wireMessage.messageIdentifier);
1292				if (this.onMessageDelivered)
1293					this.onMessageDelivered(sentMessage.payloadMessage);
1294				break;
1295
1296			case MESSAGE_TYPE.SUBACK:
1297				var sentMessage = this._sentMessages[wireMessage.messageIdentifier];
1298				if (sentMessage) {
1299					if(sentMessage.timeOut)
1300						sentMessage.timeOut.cancel();
1301					// This will need to be fixed when we add multiple topic support
1302          			if (wireMessage.returnCode[0] === 0x80) {
1303						if (sentMessage.onFailure) {
1304							sentMessage.onFailure(wireMessage.returnCode);
1305						}
1306					} else if (sentMessage.onSuccess) {
1307						sentMessage.onSuccess(wireMessage.returnCode);
1308					}
1309					delete this._sentMessages[wireMessage.messageIdentifier];
1310				}
1311				break;
1312
1313			case MESSAGE_TYPE.UNSUBACK:
1314				var sentMessage = this._sentMessages[wireMessage.messageIdentifier];
1315				if (sentMessage) {
1316					if (sentMessage.timeOut)
1317						sentMessage.timeOut.cancel();
1318					if (sentMessage.callback) {
1319						sentMessage.callback();
1320					}
1321					delete this._sentMessages[wireMessage.messageIdentifier];
1322				}
1323
1324				break;
1325
1326			case MESSAGE_TYPE.PINGRESP:
1327				/* The sendPinger or receivePinger may have sent a ping, the receivePinger has already been reset. */
1328				this.sendPinger.reset();
1329				break;
1330
1331			case MESSAGE_TYPE.DISCONNECT:
1332				// Clients do not expect to receive disconnect packets.
1333				this._disconnected(ERROR.INVALID_MQTT_MESSAGE_TYPE.code , format(ERROR.INVALID_MQTT_MESSAGE_TYPE, [wireMessage.type]));
1334				break;
1335
1336			default:
1337				this._disconnected(ERROR.INVALID_MQTT_MESSAGE_TYPE.code , format(ERROR.INVALID_MQTT_MESSAGE_TYPE, [wireMessage.type]));
1338			};
1339		} catch (error) {
1340			this._disconnected(ERROR.INTERNAL_ERROR.code , format(ERROR.INTERNAL_ERROR, [error.message,error.stack.toString()]));
1341			return;
1342		}
1343	};
1344
1345	/** @ignore */
1346	ClientImpl.prototype._on_socket_error = function (error) {
1347		this._disconnected(ERROR.SOCKET_ERROR.code , format(ERROR.SOCKET_ERROR, [error.data]));
1348	};
1349
1350	/** @ignore */
1351	ClientImpl.prototype._on_socket_close = function () {
1352		this._disconnected(ERROR.SOCKET_CLOSE.code , format(ERROR.SOCKET_CLOSE));
1353	};
1354
1355	/** @ignore */
1356	ClientImpl.prototype._socket_send = function (wireMessage) {
1357
1358		if (wireMessage.type == 1) {
1359			var wireMessageMasked = this._traceMask(wireMessage, "password");
1360			this._trace("Client._socket_send", wireMessageMasked);
1361		}
1362		else this._trace("Client._socket_send", wireMessage);
1363
1364		this.socket.send(wireMessage.encode());
1365		/* We have proved to the server we are alive. */
1366		this.sendPinger.reset();
1367	};
1368
1369	/** @ignore */
1370	ClientImpl.prototype._receivePublish = function (wireMessage) {
1371		switch(wireMessage.payloadMessage.qos) {
1372			case "undefined":
1373			case 0:
1374				this._receiveMessage(wireMessage);
1375				break;
1376
1377			case 1:
1378				var pubAckMessage = new WireMessage(MESSAGE_TYPE.PUBACK, {messageIdentifier:wireMessage.messageIdentifier});
1379				this._schedule_message(pubAckMessage);
1380				this._receiveMessage(wireMessage);
1381				break;
1382
1383			case 2:
1384				this._receivedMessages[wireMessage.messageIdentifier] = wireMessage;
1385				this.store("Received:", wireMessage);
1386				var pubRecMessage = new WireMessage(MESSAGE_TYPE.PUBREC, {messageIdentifier:wireMessage.messageIdentifier});
1387				this._schedule_message(pubRecMessage);
1388
1389				break;
1390
1391			default:
1392				throw Error("Invaild qos="+wireMmessage.payloadMessage.qos);
1393		};
1394	};
1395
1396	/** @ignore */
1397	ClientImpl.prototype._receiveMessage = function (wireMessage) {
1398		if (this.onMessageArrived) {
1399			this.onMessageArrived(wireMessage.payloadMessage);
1400		}
1401	};
1402
1403	/**
1404	 * Client has disconnected either at its own request or because the server
1405	 * or network disconnected it. Remove all non-durable state.
1406	 * @param {errorCode} [number] the error number.
1407	 * @param {errorText} [string] the error text.
1408	 * @ignore
1409	 */
1410	ClientImpl.prototype._disconnected = function (errorCode, errorText) {
1411		this._trace("Client._disconnected", errorCode, errorText);
1412
1413		this.sendPinger.cancel();
1414		this.receivePinger.cancel();
1415		if (this._connectTimeout)
1416			this._connectTimeout.cancel();
1417		// Clear message buffers.
1418		this._msg_queue = [];
1419		this._notify_msg_sent = {};
1420
1421		if (this.socket) {
1422			// Cancel all socket callbacks so that they cannot be driven again by this socket.
1423			this.socket.onopen = null;
1424			this.socket.onmessage = null;
1425			this.socket.onerror = null;
1426			this.socket.onclose = null;
1427			if (this.socket.readyState === 1)
1428				this.socket.close();
1429			delete this.socket;
1430		}
1431
1432		if (this.connectOptions.uris && this.hostIndex < this.connectOptions.uris.length-1) {
1433			// Try the next host.
1434			this.hostIndex++;
1435			this._doConnect(this.connectOptions.uris[this.hostIndex]);
1436
1437		} else {
1438
1439			if (errorCode === undefined) {
1440				errorCode = ERROR.OK.code;
1441				errorText = format(ERROR.OK);
1442			}
1443
1444			// Run any application callbacks last as they may attempt to reconnect and hence create a new socket.
1445			if (this.connected) {
1446				this.connected = false;
1447				// Execute the connectionLostCallback if there is one, and we were connected.       
1448				if (this.onConnectionLost)
1449					this.onConnectionLost({errorCode:errorCode, errorMessage:errorText});
1450			} else {
1451				// Otherwise we never had a connection, so indicate that the connect has failed.
1452				if (this.connectOptions.mqttVersion === 4 && this.connectOptions.mqttVersionExplicit === false) {
1453					this._trace("Failed to connect V4, dropping back to V3")
1454					this.connectOptions.mqttVersion = 3;
1455					if (this.connectOptions.uris) {
1456						this.hostIndex = 0;
1457						this._doConnect(this.connectOptions.uris[0]);
1458					} else {
1459						this._doConnect(this.uri);
1460					}
1461				} else if(this.connectOptions.onFailure) {
1462					this.connectOptions.onFailure({invocationContext:this.connectOptions.invocationContext, errorCode:errorCode, errorMessage:errorText});
1463				}
1464			}
1465		}
1466	};
1467
1468	/** @ignore */
1469	ClientImpl.prototype._trace = function () {
1470		// Pass trace message back to client's callback function
1471		if (this.traceFunction) {
1472			for (var i in arguments)
1473			{
1474				if (typeof arguments[i] !== "undefined")
1475					arguments[i] = JSON.stringify(arguments[i]);
1476			}
1477			var record = Array.prototype.slice.call(arguments).join("");
1478			this.traceFunction ({severity: "Debug", message: record	});
1479		}
1480
1481		//buffer style trace
1482		if ( this._traceBuffer !== null ) {
1483			for (var i = 0, max = arguments.length; i < max; i++) {
1484				if ( this._traceBuffer.length == this._MAX_TRACE_ENTRIES ) {
1485					this._traceBuffer.shift();
1486				}
1487				if (i === 0) this._traceBuffer.push(arguments[i]);
1488				else if (typeof arguments[i] === "undefined" ) this._traceBuffer.push(arguments[i]);
1489				else this._traceBuffer.push("  "+JSON.stringify(arguments[i]));
1490		   };
1491		};
1492	};
1493
1494	/** @ignore */
1495	ClientImpl.prototype._traceMask = function (traceObject, masked) {
1496		var traceObjectMasked = {};
1497		for (var attr in traceObject) {
1498			if (traceObject.hasOwnProperty(attr)) {
1499				if (attr == masked)
1500					traceObjectMasked[attr] = "******";
1501				else
1502					traceObjectMasked[attr] = traceObject[attr];
1503			}
1504		}
1505		return traceObjectMasked;
1506	};
1507
1508	// ------------------------------------------------------------------------
1509	// Public Programming interface.
1510	// ------------------------------------------------------------------------
1511
1512	/**
1513	 * The JavaScript application communicates to the server using a {@link Paho.MQTT.Client} object.
1514	 * <p>
1515	 * Most applications will create just one Client object and then call its connect() method,
1516	 * however applications can create more than one Client object if they wish.
1517	 * In this case the combination of host, port and clientId attributes must be different for each Client object.
1518	 * <p>
1519	 * The send, subscribe and unsubscribe methods are implemented as asynchronous JavaScript methods
1520	 * (even though the underlying protocol exchange might be synchronous in nature).
1521	 * This means they signal their completion by calling back to the application,
1522	 * via Success or Failure callback functions provided by the application on the method in question.
1523	 * Such callbacks are called at most once per method invocation and do not persist beyond the lifetime
1524	 * of the script that made the invocation.
1525	 * <p>
1526	 * In contrast there are some callback functions, most notably <i>onMessageArrived</i>,
1527	 * that are defined on the {@link Paho.MQTT.Client} object.
1528	 * These may get called multiple times, and aren't directly related to specific method invocations made by the client.
1529	 *
1530	 * @name Paho.MQTT.Client
1531	 *
1532	 * @constructor
1533	 *
1534	 * @param {string} host - the address of the messaging server, as a fully qualified WebSocket URI, as a DNS name or dotted decimal IP address.
1535	 * @param {number} port - the port number to connect to - only required if host is not a URI
1536	 * @param {string} path - the path on the host to connect to - only used if host is not a URI. Default: '/mqtt'.
1537	 * @param {string} clientId - the Messaging client identifier, between 1 and 23 characters in length.
1538	 *
1539	 * @property {string} host - <i>read only</i> the server's DNS hostname or dotted decimal IP address.
1540	 * @property {number} port - <i>read only</i> the server's port.
1541	 * @property {string} path - <i>read only</i> the server's path.
1542	 * @property {string} clientId - <i>read only</i> used when connecting to the server.
1543	 * @property {function} onConnectionLost - called when a connection has been lost.
1544	 *                            after a connect() method has succeeded.
1545	 *                            Establish the call back used when a connection has been lost. The connection may be
1546	 *                            lost because the client initiates a disconnect or because the server or network
1547	 *                            cause the client to be disconnected. The disconnect call back may be called without
1548	 *                            the connectionComplete call back being invoked if, for example the client fails to
1549	 *                            connect.
1550	 *                            A single response object parameter is passed to the onConnectionLost callback containing the following fields:
1551	 *                            <ol>
1552	 *                            <li>errorCode
1553	 *                            <li>errorMessage
1554	 *                            </ol>
1555	 * @property {function} onMessageDelivered called when a message has been delivered.
1556	 *                            All processing that this Client will ever do has been completed. So, for example,
1557	 *                            in the case of a Qos=2 message sent by this client, the PubComp flow has been received from the server
1558	 *                            and the message has been removed from persistent storage before this callback is invoked.
1559	 *                            Parameters passed to the onMessageDelivered callback are:
1560	 *                            <ol>
1561	 *                            <li>{@link Paho.MQTT.Message} that was delivered.
1562	 *                            </ol>
1563	 * @property {function} onMessageArrived called when a message has arrived in this Paho.MQTT.client.
1564	 *                            Parameters passed to the onMessageArrived callback are:
1565	 *                            <ol>
1566	 *                            <li>{@link Paho.MQTT.Message} that has arrived.
1567	 *                            </ol>
1568	 */
1569	var Client = function (host, port, path, clientId) {
1570
1571	    var uri;
1572
1573		if (typeof host !== "string")
1574			throw new Error(format(ERROR.INVALID_TYPE, [typeof host, "host"]));
1575
1576	    if (arguments.length == 2) {
1577	        // host: must be full ws:// uri
1578	        // port: clientId
1579	        clientId = port;
1580	        uri = host;
1581	        var match = uri.match(/^(wss?):\/\/((\[(.+)\])|([^\/]+?))(:(\d+))?(\/.*)$/);
1582	        if (match) {
1583	            host = match[4]||match[2];
1584	            port = parseInt(match[7]);
1585	            path = match[8];
1586	        } else {
1587	            throw new Error(format(ERROR.INVALID_ARGUMENT,[host,"host"]));
1588	        }
1589	    } else {
1590	        if (arguments.length == 3) {
1591				clientId = path;
1592				path = "/mqtt";
1593			}
1594			if (typeof port !== "number" || port < 0)
1595				throw new Error(format(ERROR.INVALID_TYPE, [typeof port, "port"]));
1596			if (typeof path !== "string")
1597				throw new Error(format(ERROR.INVALID_TYPE, [typeof path, "path"]));
1598
1599			var ipv6AddSBracket = (host.indexOf(":") != -1 && host.slice(0,1) != "[" && host.slice(-1) != "]");
1600			uri = "ws://"+(ipv6AddSBracket?"["+host+"]":host)+":"+port+path;
1601		}
1602
1603		var clientIdLength = 0;
1604		for (var i = 0; i<clientId.length; i++) {
1605			var charCode = clientId.charCodeAt(i);
1606			if (0xD800 <= charCode && charCode <= 0xDBFF)  {
1607				 i++; // Surrogate pair.
1608			}
1609			clientIdLength++;
1610		}
1611		if (typeof clientId !== "string" || clientIdLength > 65535)
1612			throw new Error(format(ERROR.INVALID_ARGUMENT, [clientId, "clientId"]));
1613
1614		var client = new ClientImpl(uri, host, port, path, clientId);
1615		this._getHost =  function() { return host; };
1616		this._setHost = function() { throw new Error(format(ERROR.UNSUPPORTED_OPERATION)); };
1617
1618		this._getPort = function() { return port; };
1619		this._setPort = function() { throw new Error(format(ERROR.UNSUPPORTED_OPERATION)); };
1620
1621		this._getPath = function() { return path; };
1622		this._setPath = function() { throw new Error(format(ERROR.UNSUPPORTED_OPERATION)); };
1623
1624		this._getURI = function() { return uri; };
1625		this._setURI = function() { throw new Error(format(ERROR.UNSUPPORTED_OPERATION)); };
1626
1627		this._getClientId = function() { return client.clientId; };
1628		this._setClientId = function() { throw new Error(format(ERROR.UNSUPPORTED_OPERATION)); };
1629
1630		this._getOnConnectionLost = function() { return client.onConnectionLost; };
1631		this._setOnConnectionLost = function(newOnConnectionLost) {
1632			if (typeof newOnConnectionLost === "function")
1633				client.onConnectionLost = newOnConnectionLost;
1634			else
1635				throw new Error(format(ERROR.INVALID_TYPE, [typeof newOnConnectionLost, "onConnectionLost"]));
1636		};
1637
1638		this._getOnMessageDelivered = function() { return client.onMessageDelivered; };
1639		this._setOnMessageDelivered = function(newOnMessageDelivered) {
1640			if (typeof newOnMessageDelivered === "function")
1641				client.onMessageDelivered = newOnMessageDelivered;
1642			else
1643				throw new Error(format(ERROR.INVALID_TYPE, [typeof newOnMessageDelivered, "onMessageDelivered"]));
1644		};
1645
1646		this._getOnMessageArrived = function() { return client.onMessageArrived; };
1647		this._setOnMessageArrived = function(newOnMessageArrived) {
1648			if (typeof newOnMessageArrived === "function")
1649				client.onMessageArrived = newOnMessageArrived;
1650			else
1651				throw new Error(format(ERROR.INVALID_TYPE, [typeof newOnMessageArrived, "onMessageArrived"]));
1652		};
1653
1654		this._getTrace = function() { return client.traceFunction; };
1655		this._setTrace = function(trace) {
1656			if(typeof trace === "function"){
1657				client.traceFunction = trace;
1658			}else{
1659				throw new Error(format(ERROR.INVALID_TYPE, [typeof trace, "onTrace"]));
1660			}
1661		};
1662
1663		/**
1664		 * Connect this Messaging client to its server.
1665		 *
1666		 * @name Paho.MQTT.Client#connect
1667		 * @function
1668		 * @param {Object} connectOptions - attributes used with the connection.
1669		 * @param {number} connectOptions.timeout - If the connect has not succeeded within this
1670		 *                    number of seconds, it is deemed to have failed.
1671		 *                    The default is 30 seconds.
1672		 * @param {string} connectOptions.userName - Authentication username for this connection.
1673		 * @param {string} connectOptions.password - Authentication password for this connection.
1674		 * @param {Paho.MQTT.Message} connectOptions.willMessage - sent by the server when the client
1675		 *                    disconnects abnormally.
1676		 * @param {Number} connectOptions.keepAliveInterval - the server disconnects this client if
1677		 *                    there is no activity for this number of seconds.
1678		 *                    The default value of 60 seconds is assumed if not set.
1679		 * @param {boolean} connectOptions.cleanSession - if true(default) the client and server
1680		 *                    persistent state is deleted on successful connect.
1681		 * @param {boolean} connectOptions.useSSL - if present and true, use an SSL Websocket connection.
1682		 * @param {object} connectOptions.invocationContext - passed to the onSuccess callback or onFailure callback.
1683		 * @param {function} connectOptions.onSuccess - called when the connect acknowledgement
1684		 *                    has been received from the server.
1685		 * A single response object parameter is passed to the onSuccess callback containing the following fields:
1686		 * <ol>
1687		 * <li>invocationContext as passed in to the onSuccess method in the connectOptions.
1688		 * </ol>
1689		 * @config {function} [onFailure] called when the connect request has failed or timed out.
1690		 * A single response object parameter is passed to the onFailure callback containing the following fields:
1691		 * <ol>
1692		 * <li>invocationContext as passed in to the onFailure method in the connectOptions.
1693		 * <li>errorCode a number indicating the nature of the error.
1694		 * <li>errorMessage text describing the error.
1695		 * </ol>
1696		 * @config {Array} [hosts] If present this contains either a set of hostnames or fully qualified
1697		 * WebSocket URIs (ws://example.com:1883/mqtt), that are tried in order in place
1698		 * of the host and port paramater on the construtor. The hosts are tried one at at time in order until
1699		 * one of then succeeds.
1700		 * @config {Array} [ports] If present the set of ports matching the hosts. If hosts contains URIs, this property
1701		 * is not used.
1702		 * @throws {InvalidState} if the client is not in disconnected state. The client must have received connectionLost
1703		 * or disconnected before calling connect for a second or subsequent time.
1704		 */
1705		this.connect = function (connectOptions) {
1706			connectOptions = connectOptions || {} ;
1707			validate(connectOptions,  {timeout:"number",
1708									   userName:"string",
1709									   password:"string",
1710									   willMessage:"object",
1711									   keepAliveInterval:"number",
1712									   cleanSession:"boolean",
1713									   useSSL:"boolean",
1714									   invocationContext:"object",
1715									   onSuccess:"function",
1716									   onFailure:"function",
1717									   hosts:"object",
1718									   ports:"object",
1719									   mqttVersion:"number"});
1720
1721			// If no keep alive interval is set, assume 60 seconds.
1722			if (connectOptions.keepAliveInterval === undefined)
1723				connectOptions.keepAliveInterval = 60;
1724
1725			if (connectOptions.mqttVersion > 4 || connectOptions.mqttVersion < 3) {
1726				throw new Error(format(ERROR.INVALID_ARGUMENT, [connectOptions.mqttVersion, "connectOptions.mqttVersion"]));
1727			}
1728
1729			if (connectOptions.mqttVersion === undefined) {
1730				connectOptions.mqttVersionExplicit = false;
1731				connectOptions.mqttVersion = 4;
1732			} else {
1733				connectOptions.mqttVersionExplicit = true;
1734			}
1735
1736			//Check that if password is set, so is username
1737			if (connectOptions.password === undefined && connectOptions.userName !== undefined)
1738				throw new Error(format(ERROR.INVALID_ARGUMENT, [connectOptions.password, "connectOptions.password"]))
1739
1740			if (connectOptions.willMessage) {
1741				if (!(connectOptions.willMessage instanceof Message))
1742					throw new Error(format(ERROR.INVALID_TYPE, [connectOptions.willMessage, "connectOptions.willMessage"]));
1743				// The will message must have a payload that can be represented as a string.
1744				// Cause the willMessage to throw an exception if this is not the case.
1745				connectOptions.willMessage.stringPayload;
1746
1747				if (typeof connectOptions.willMessage.destinationName === "undefined")
1748					throw new Error(format(ERROR.INVALID_TYPE, [typeof connectOptions.willMessage.destinationName, "connectOptions.willMessage.destinationName"]));
1749			}
1750			if (typeof connectOptions.cleanSession === "undefined")
1751				connectOptions.cleanSession = true;
1752			if (connectOptions.hosts) {
1753
1754				if (!(connectOptions.hosts instanceof Array) )
1755					throw new Error(format(ERROR.INVALID_ARGUMENT, [connectOptions.hosts, "connectOptions.hosts"]));
1756				if (connectOptions.hosts.length <1 )
1757					throw new Error(format(ERROR.INVALID_ARGUMENT, [connectOptions.hosts, "connectOptions.hosts"]));
1758
1759				var usingURIs = false;
1760				for (var i = 0; i<connectOptions.hosts.length; i++) {
1761					if (typeof connectOptions.hosts[i] !== "string")
1762						throw new Error(format(ERROR.INVALID_TYPE, [typeof connectOptions.hosts[i], "connectOptions.hosts["+i+"]"]));
1763					if (/^(wss?):\/\/((\[(.+)\])|([^\/]+?))(:(\d+))?(\/.*)$/.test(connectOptions.hosts[i])) {
1764						if (i == 0) {
1765							usingURIs = true;
1766						} else if (!usingURIs) {
1767							throw new Error(format(ERROR.INVALID_ARGUMENT, [connectOptions.hosts[i], "connectOptions.hosts["+i+"]"]));
1768						}
1769					} else if (usingURIs) {
1770						throw new Error(format(ERROR.INVALID_ARGUMENT, [connectOptions.hosts[i], "connectOptions.hosts["+i+"]"]));
1771					}
1772				}
1773
1774				if (!usingURIs) {
1775					if (!connectOptions.ports)
1776						throw new Error(format(ERROR.INVALID_ARGUMENT, [connectOptions.ports, "connectOptions.ports"]));
1777					if (!(connectOptions.ports instanceof Array) )
1778						throw new Error(format(ERROR.INVALID_ARGUMENT, [connectOptions.ports, "connectOptions.ports"]));
1779					if (connectOptions.hosts.length != connectOptions.ports.length)
1780						throw new Error(format(ERROR.INVALID_ARGUMENT, [connectOptions.ports, "connectOptions.ports"]));
1781
1782					connectOptions.uris = [];
1783
1784					for (var i = 0; i<connectOptions.hosts.length; i++) {
1785						if (typeof connectOptions.ports[i] !== "number" || connectOptions.ports[i] < 0)
1786							throw new Error(format(ERROR.INVALID_TYPE, [typeof connectOptions.ports[i], "connectOptions.ports["+i+"]"]));
1787						var host = connectOptions.hosts[i];
1788						var port = connectOptions.ports[i];
1789
1790						var ipv6 = (host.indexOf(":") != -1);
1791						uri = "ws://"+(ipv6?"["+host+"]":host)+":"+port+path;
1792						connectOptions.uris.push(uri);
1793					}
1794				} else {
1795					connectOptions.uris = connectOptions.hosts;
1796				}
1797			}
1798
1799			client.connect(connectOptions);
1800		};
1801
1802		/**
1803		 * Subscribe for messages, request receipt of a copy of messages sent to the destinations described by the filter.
1804		 *
1805		 * @name Paho.MQTT.Client#subscribe
1806		 * @function
1807		 * @param {string} filter describing the destinations to receive messages from.
1808		 * <br>
1809		 * @param {object} subscribeOptions - used to control the subscription
1810		 *
1811		 * @param {number} subscribeOptions.qos - the maiximum qos of any publications sent
1812		 *                                  as a result of making this subscription.
1813		 * @param {object} subscribeOptions.invocationContext - passed to the onSuccess callback
1814		 *                                  or onFailure callback.
1815		 * @param {function} subscribeOptions.onSuccess - called when the subscribe acknowledgement
1816		 *                                  has been received from the server.
1817		 *                                  A single response object parameter is passed to the onSuccess callback containing the following fields:
1818		 *                                  <ol>
1819		 *                                  <li>invocationContext if set in the subscribeOptions.
1820		 *                                  </ol>
1821		 * @param {function} subscribeOptions.onFailure - called when the subscribe request has failed or timed out.
1822		 *                                  A single response object parameter is passed to the onFailure callback containing the following fields:
1823		 *                                  <ol>
1824		 *                                  <li>invocationContext - if set in the subscribeOptions.
1825		 *                                  <li>errorCode - a number indicating the nature of the error.
1826		 *                                  <li>errorMessage - text describing the error.
1827		 *                                  </ol>
1828		 * @param {number} subscribeOptions.timeout - which, if present, determines the number of
1829		 *                                  seconds after which the onFailure calback is called.
1830		 *                                  The presence of a timeout does not prevent the onSuccess
1831		 *                                  callback from being called when the subscribe completes.
1832		 * @throws {InvalidState} if the client is not in connected state.
1833		 */
1834		this.subscribe = function (filter, subscribeOptions) {
1835			if (typeof filter !== "string")
1836				throw new Error("Invalid argument:"+filter);
1837			subscribeOptions = subscribeOptions || {} ;
1838			validate(subscribeOptions,  {qos:"number",
1839										 invocationContext:"object",
1840										 onSuccess:"function",
1841										 onFailure:"function",
1842										 timeout:"number"
1843										});
1844			if (subscribeOptions.timeout && !subscribeOptions.onFailure)
1845				throw new Error("subscribeOptions.timeout specified with no onFailure callback.");
1846			if (typeof subscribeOptions.qos !== "undefined"
1847				&& !(subscribeOptions.qos === 0 || subscribeOptions.qos === 1 || subscribeOptions.qos === 2 ))
1848				throw new Error(format(ERROR.INVALID_ARGUMENT, [subscribeOptions.qos, "subscribeOptions.qos"]));
1849			client.subscribe(filter, subscribeOptions);
1850		};
1851
1852		/**
1853		 * Unsubscribe for messages, stop receiving messages sent to destinations described by the filter.
1854		 *
1855		 * @name Paho.MQTT.Client#unsubscribe
1856		 * @function
1857		 * @param {string} filter - describing the destinations to receive messages from.
1858		 * @param {object} unsubscribeOptions - used to control the subscription
1859		 * @param {object} unsubscribeOptions.invocationContext - passed to the onSuccess callback
1860		                                      or onFailure callback.
1861		 * @param {function} unsubscribeOptions.onSuccess - called when the unsubscribe acknowledgement has been received from the server.
1862		 *                                    A single response object parameter is passed to the
1863		 *                                    onSuccess callback containing the following fields:
1864		 *                                    <ol>
1865		 *                                    <li>invocationContext - if set in the unsubscribeOptions.
1866		 *                                    </ol>
1867		 * @param {function} unsubscribeOptions.onFailure called when the unsubscribe request has failed or timed out.
1868		 *                                    A single response object parameter is passed to the onFailure callback containing the following fields:
1869		 *                                    <ol>
1870		 *                                    <li>invocationContext - if set in the unsubscribeOptions.
1871		 *                                    <li>errorCode - a number indicating the nature of the error.
1872		 *                                    <li>errorMessage - text describing the error.
1873		 *                                    </ol>
1874		 * @param {number} unsubscribeOptions.timeout - which, if present, determines the number of seconds
1875		 *                                    after which the onFailure callback is called. The presence of
1876		 *                                    a timeout does not prevent the onSuccess callback from being
1877		 *                                    called when the unsubscribe completes
1878		 * @throws {InvalidState} if the client is not in connected state.
1879		 */
1880		this.unsubscribe = function (filter, unsubscribeOptions) {
1881			if (typeof filter !== "string")
1882				throw new Error("Invalid argument:"+filter);
1883			unsubscribeOptions = unsubscribeOptions || {} ;
1884			validate(unsubscribeOptions,  {invocationContext:"object",
1885										   onSuccess:"function",
1886										   onFailure:"function",
1887										   timeout:"number"
1888										  });
1889			if (unsubscribeOptions.timeout && !unsubscribeOptions.onFailure)
1890				throw new Error("unsubscribeOptions.timeout specified with no onFailure callback.");
1891			client.unsubscribe(filter, unsubscribeOptions);
1892		};
1893
1894		/**
1895		 * Send a message to the consumers of the destination in the Message.
1896		 *
1897		 * @name Paho.MQTT.Client#send
1898		 * @function
1899		 * @param {string|Paho.MQTT.Message} topic - <b>mandatory</b> The name of the destination to which the message is to be sent.
1900		 * 					   - If it is the only parameter, used as Paho.MQTT.Message object.
1901		 * @param {String|ArrayBuffer} payload - The message data to be sent.
1902		 * @param {number} qos The Quality of Service used to deliver the message.
1903		 * 		<dl>
1904		 * 			<dt>0 Best effort (default).
1905		 *     			<dt>1 At least once.
1906		 *     			<dt>2 Exactly once.
1907		 * 		</dl>
1908		 * @param {Boolean} retained If true, the message is to be retained by the server and delivered
1909		 *                     to both current and future subscriptions.
1910		 *                     If false the server only delivers the message to current subscribers, this is the default for new Messages.
1911		 *                     A received message has the retained boolean set to true if the message was published
1912		 *                     with the retained boolean set to true
1913		 *                     and the subscrption was made after the message has been published.
1914		 * @throws {InvalidState} if the client is not connected.
1915		 */
1916		this.send = function (topic,payload,qos,retained) {
1917			var message ;
1918
1919			if(arguments.length == 0){
1920				throw new Error("Invalid argument."+"length");
1921
1922			}else if(arguments.length == 1) {
1923
1924				if (!(topic instanceof Message) && (typeof topic !== "string"))
1925					throw new Error("Invalid argument:"+ typeof topic);
1926
1927				message = topic;
1928				if (typeof message.destinationName === "undefined")
1929					throw new Error(format(ERROR.INVALID_ARGUMENT,[message.destinationName,"Message.destinationName"]));
1930				client.send(message);
1931
1932			}else {
1933				//parameter checking in Message object 
1934				message = new Message(payload);
1935				message.destinationName = topic;
1936				if(arguments.length >= 3)
1937					message.qos = qos;
1938				if(arguments.length >= 4)
1939					message.retained = retained;
1940				client.send(message);
1941			}
1942		};
1943
1944		/**
1945		 * Normal disconnect of this Messaging client from its server.
1946		 *
1947		 * @name Paho.MQTT.Client#disconnect
1948		 * @function
1949		 * @throws {InvalidState} if the client is already disconnected.
1950		 */
1951		this.disconnect = function () {
1952			client.disconnect();
1953		};
1954
1955		/**
1956		 * Get the contents of the trace log.
1957		 *
1958		 * @name Paho.MQTT.Client#getTraceLog
1959		 * @function
1960		 * @return {Object[]} tracebuffer containing the time ordered trace records.
1961		 */
1962		this.getTraceLog = function () {
1963			return client.getTraceLog();
1964		}
1965
1966		/**
1967		 * Start tracing.
1968		 *
1969		 * @name Paho.MQTT.Client#startTrace
1970		 * @function
1971		 */
1972		this.startTrace = function () {
1973			client.startTrace();
1974		};
1975
1976		/**
1977		 * Stop tracing.
1978		 *
1979		 * @name Paho.MQTT.Client#stopTrace
1980		 * @function
1981		 */
1982		this.stopTrace = function () {
1983			client.stopTrace();
1984		};
1985
1986		this.isConnected = function() {
1987			return client.connected;
1988		};
1989	};
1990
1991	Client.prototype = {
1992		get host() { return this._getHost(); },
1993		set host(newHost) { this._setHost(newHost); },
1994
1995		get port() { return this._getPort(); },
1996		set port(newPort) { this._setPort(newPort); },
1997
1998		get path() { return this._getPath(); },
1999		set path(newPath) { this._setPath(newPath); },
2000
2001		get clientId() { return this._getClientId(); },
2002		set clientId(newClientId) { this._setClientId(newClientId); },
2003
2004		get onConnectionLost() { return this._getOnConnectionLost(); },
2005		set onConnectionLost(newOnConnectionLost) { this._setOnConnectionLost(newOnConnectionLost); },
2006
2007		get onMessageDelivered() { return this._getOnMessageDelivered(); },
2008		set onMessageDelivered(newOnMessageDelivered) { this._setOnMessageDelivered(newOnMessageDelivered); },
2009
2010		get onMessageArrived() { return this._getOnMessageArrived(); },
2011		set onMessageArrived(newOnMessageArrived) { this._setOnMessageArrived(newOnMessageArrived); },
2012
2013		get trace() { return this._getTrace(); },
2014		set trace(newTraceFunction) { this._setTrace(newTraceFunction); }
2015
2016	};
2017
2018	/**
2019	 * An application message, sent or received.
2020	 * <p>
2021	 * All attributes may be null, which implies the default values.
2022	 *
2023	 * @name Paho.MQTT.Message
2024	 * @constructor
2025	 * @param {String|ArrayBuffer} payload The message data to be sent.
2026	 * <p>
2027	 * @property {string} payloadString <i>read only</i> The payload as a string if the payload consists of valid UTF-8 characters.
2028	 * @property {ArrayBuffer} payloadBytes <i>read only</i> The payload as an ArrayBuffer.
2029	 * <p>
2030	 * @property {string} destinationName <b>mandatory</b> The name of the destination to which the message is to be sent
2031	 *                    (for messages about to be sent) or the name of the destination from which the message has been received.
2032	 *                    (for messages received by the onMessage function).
2033	 * <p>
2034	 * @property {number} qos The Quality of Service used to deliver the message.
2035	 * <dl>
2036	 *     <dt>0 Best effort (default).
2037	 *     <dt>1 At least once.
2038	 *     <dt>2 Exactly once.
2039	 * </dl>
2040	 * <p>
2041	 * @property {Boolean} retained If true, the message is to be retained by the server and delivered
2042	 *                     to both current and future subscriptions.
2043	 *                     If false the server only delivers the message to current subscribers, this is the default for new Messages.
2044	 *                     A received message has the retained boolean set to true if the message was published
2045	 *                     with the retained boolean set to true
2046	 *                     and the subscrption was made after the message has been published.
2047	 * <p>
2048	 * @property {Boolean} duplicate <i>read only</i> If true, this message might be a duplicate of one which has already been received.
2049	 *                     This is only set on messages received from the server.
2050	 *
2051	 */
2052	var Message = function (newPayload) {
2053		var payload;
2054		if (   typeof newPayload === "string"
2055			|| newPayload instanceof ArrayBuffer
2056			|| newPayload instanceof Int8Array
2057			|| newPayload instanceof Uint8Array
2058			|| newPayload instanceof Int16Array
2059			|| newPayload instanceof Uint16Array
2060			|| newPayload instanceof Int32Array
2061			|| newPayload instanceof Uint32Array
2062			|| newPayload instanceof Float32Array
2063			|| newPayload instanceof Float64Array
2064		   ) {
2065			payload = newPayload;
2066		} else {
2067			throw (format(ERROR.INVALID_ARGUMENT, [newPayload, "newPayload"]));
2068		}
2069
2070		this._getPayloadString = function () {
2071			if (typeof payload === "string")
2072				return payload;
2073			else
2074				return parseUTF8(payload, 0, payload.length);
2075		};
2076
2077		this._getPayloadBytes = function() {
2078			if (typeof payload === "string") {
2079				var buffer = new ArrayBuffer(UTF8Length(payload));
2080				var byteStream = new Uint8Array(buffer);
2081				stringToUTF8(payload, byteStream, 0);
2082
2083				return byteStream;
2084			} else {
2085				return payload;
2086			};
2087		};
2088
2089		var destinationName = undefined;
2090		this._getDestinationName = function() { return destinationName; };
2091		this._setDestinationName = function(newDestinationName) {
2092			if (typeof newDestinationName === "string")
2093				destinationName = newDestinationName;
2094			else
2095				throw new Error(format(ERROR.INVALID_ARGUMENT, [newDestinationName, "newDestinationName"]));
2096		};
2097
2098		var qos = 0;
2099		this._getQos = function() { return qos; };
2100		this._setQos = function(newQos) {
2101			if (newQos === 0 || newQos === 1 || newQos === 2 )
2102				qos = newQos;
2103			else
2104				throw new Error("Invalid argument:"+newQos);
2105		};
2106
2107		var retained = false;
2108		this._getRetained = function() { return retained; };
2109		this._setRetained = function(newRetained) {
2110			if (typeof newRetained === "boolean")
2111				retained = newRetained;
2112			else
2113				throw new Error(format(ERROR.INVALID_ARGUMENT, [newRetained, "newRetained"]));
2114		};
2115
2116		var duplicate = false;
2117		this._getDuplicate = function() { return duplicate; };
2118		this._setDuplicate = function(newDuplicate) { duplicate = newDuplicate; };
2119	};
2120
2121	Message.prototype = {
2122		get payloadString() { return this._getPayloadString(); },
2123		get payloadBytes() { return this._getPayloadBytes(); },
2124
2125		get destinationName() { return this._getDestinationName(); },
2126		set destinationName(newDestinationName) { this._setDestinationName(newDestinationName); },
2127
2128		get qos() { return this._getQos(); },
2129		set qos(newQos) { this._setQos(newQos); },
2130
2131		get retained() { return this._getRetained(); },
2132		set retained(newRetained) { this._setRetained(newRetained); },
2133
2134		get duplicate() { return this._getDuplicate(); },
2135		set duplicate(newDuplicate) { this._setDuplicate(newDuplicate); }
2136	};
2137
2138	// Module contents.
2139	return {
2140		Client: Client,
2141		Message: Message
2142	};
2143})(window);