53 lines
2.2 KiB
JavaScript
53 lines
2.2 KiB
JavaScript
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dojo.provide("dojox.uuid.generateRandomUuid");
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dojox.uuid.generateRandomUuid = function(){
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// summary:
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// This function generates random UUIDs, meaning "version 4" UUIDs.
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// description:
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// A typical generated value would be something like this:
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// "3b12f1df-5232-4804-897e-917bf397618a"
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//
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// For more information about random UUIDs, see sections 4.4 and
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// 4.5 of RFC 4122: http://tools.ietf.org/html/rfc4122#section-4.4
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//
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// This generator function is designed to be small and fast,
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// but not necessarily good.
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//
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// Small: This generator has a small footprint. Once comments are
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// stripped, it's only about 25 lines of code, and it doesn't
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// dojo.require() any other modules.
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//
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// Fast: This generator can generate lots of new UUIDs fairly quickly
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// (at least, more quickly than the other dojo UUID generators).
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//
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// Not necessarily good: We use Math.random() as our source
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// of randomness, which may or may not provide much randomness.
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// examples:
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// var string = dojox.uuid.generateRandomUuid();
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var HEX_RADIX = 16;
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function _generateRandomEightCharacterHexString(){
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// Make random32bitNumber be a randomly generated floating point number
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// between 0 and (4,294,967,296 - 1), inclusive.
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var random32bitNumber = Math.floor( (Math.random() % 1) * Math.pow(2, 32) );
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var eightCharacterHexString = random32bitNumber.toString(HEX_RADIX);
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while(eightCharacterHexString.length < 8){
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eightCharacterHexString = "0" + eightCharacterHexString;
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}
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return eightCharacterHexString; // for example: "3B12F1DF"
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}
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var hyphen = "-";
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var versionCodeForRandomlyGeneratedUuids = "4"; // 8 == binary2hex("0100")
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var variantCodeForDCEUuids = "8"; // 8 == binary2hex("1000")
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var a = _generateRandomEightCharacterHexString();
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var b = _generateRandomEightCharacterHexString();
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b = b.substring(0, 4) + hyphen + versionCodeForRandomlyGeneratedUuids + b.substring(5, 8);
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var c = _generateRandomEightCharacterHexString();
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c = variantCodeForDCEUuids + c.substring(1, 4) + hyphen + c.substring(4, 8);
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var d = _generateRandomEightCharacterHexString();
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var returnValue = a + hyphen + b + hyphen + c + d;
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returnValue = returnValue.toLowerCase();
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return returnValue; // String
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};
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