/*	Copyright (c) 2004-2006, The Dojo Foundation	All Rights Reserved.	Licensed under the Academic Free License version 2.1 or above OR the	modified BSD license. For more information on Dojo licensing, see:		http://dojotoolkit.org/community/licensing.shtml*/dojo.provide("dojo.uuid.LightweightGenerator");/** * The LightweightGenerator is intended to be small and fast, * but not necessarily good. *  * Small: The LightweightGenerator has a small footprint.  * Once comments are stripped, it's only about 25 lines of  * code, and it doesn't dojo.require() any other packages. * * Fast: The LightweightGenerator can generate lots of new  * UUIDs fairly quickly (at least, more quickly than the other  * dojo UUID generators). * * Not necessarily good: We use Math.random() as our source * of randomness, which may or may not provide much randomness.  */dojo.uuid.LightweightGenerator = new function() {	var HEX_RADIX = 16;// --------------------------------------------------// Private functions// --------------------------------------------------	function _generateRandomEightCharacterHexString() {		// Make random32bitNumber be a randomly generated floating point number		// between 0 and (4,294,967,296 - 1), inclusive.		var random32bitNumber = Math.floor( (Math.random() % 1) * Math.pow(2, 32) );		var eightCharacterHexString = random32bitNumber.toString(HEX_RADIX);		while (eightCharacterHexString.length < 8) {			eightCharacterHexString = "0" + eightCharacterHexString;		}		return eightCharacterHexString; // for example: "3B12F1DF"	}// --------------------------------------------------// Public functions// --------------------------------------------------/** * This function generates random UUIDs, meaning "version 4" UUIDs. * For example, a typical generated value would be something like * "3b12f1df-5232-4804-897e-917bf397618a". * * Examples: * <pre> *   var string = dojo.uuid.LightweightGenerator.generate(); *   var string = dojo.uuid.LightweightGenerator.generate(String); *   var uuid   = dojo.uuid.LightweightGenerator.generate(dojo.uuid.Uuid); * </pre> * * @param	returnType	Optional. The type of instance to return. * @return	A newly generated version 4 UUID. */	this.generate = function(returnType) {		var hyphen = "-";		var versionCodeForRandomlyGeneratedUuids = "4"; // 8 == binary2hex("0100")		var variantCodeForDCEUuids = "8"; // 8 == binary2hex("1000")		var a = _generateRandomEightCharacterHexString();		var b = _generateRandomEightCharacterHexString();		b = b.substring(0, 4) + hyphen + versionCodeForRandomlyGeneratedUuids + b.substring(5, 8);		var c = _generateRandomEightCharacterHexString();		c = variantCodeForDCEUuids + c.substring(1, 4) + hyphen + c.substring(4, 8);		var d = _generateRandomEightCharacterHexString();		var returnValue = a + hyphen + b + hyphen + c + d;		returnValue = returnValue.toLowerCase();		if (returnType && (returnType != String)) {			returnValue = new returnType(returnValue);		}		return returnValue;	};}();