| /* |
| 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.TimeBasedGenerator"); |
| dojo.require("dojo.lang.common"); |
| dojo.require("dojo.lang.type"); |
| dojo.require("dojo.lang.assert"); |
| |
| dojo.uuid.TimeBasedGenerator = new function() { |
| |
| // -------------------------------------------------- |
| // Public constants: |
| // Number of hours between October 15, 1582 and January 1, 1970: |
| this.GREGORIAN_CHANGE_OFFSET_IN_HOURS = 3394248; |
| // Number of seconds between October 15, 1582 and January 1, 1970: |
| // this.GREGORIAN_CHANGE_OFFSET_IN_SECONDS = 12219292800; |
| |
| // -------------------------------------------------- |
| // Private variables: |
| var _uuidPseudoNodeString = null; |
| var _uuidClockSeqString = null; |
| var _dateValueOfPreviousUuid = null; |
| var _nextIntraMillisecondIncrement = 0; |
| var _cachedMillisecondsBetween1582and1970 = null; |
| var _cachedHundredNanosecondIntervalsPerMillisecond = null; |
| var _uniformNode = null; |
| |
| // -------------------------------------------------- |
| // Private constants: |
| var HEX_RADIX = 16; |
| |
| function _carry(/* array */ arrayA) { |
| // summary: |
| // Given an array which holds a 64-bit number broken into 4 16-bit |
| // elements, this method carries any excess bits (greater than 16-bits) |
| // from each array element into the next. |
| // arrayA: An array with 4 elements, each of which is a 16-bit number. |
| arrayA[2] += arrayA[3] >>> 16; |
| arrayA[3] &= 0xFFFF; |
| arrayA[1] += arrayA[2] >>> 16; |
| arrayA[2] &= 0xFFFF; |
| arrayA[0] += arrayA[1] >>> 16; |
| arrayA[1] &= 0xFFFF; |
| dojo.lang.assert((arrayA[0] >>> 16) === 0); |
| } |
| |
| function _get64bitArrayFromFloat(/* float */ x) { |
| // summary: |
| // Given a floating point number, this method returns an array which |
| // holds a 64-bit number broken into 4 16-bit elements. |
| var result = new Array(0, 0, 0, 0); |
| result[3] = x % 0x10000; |
| x -= result[3]; |
| x /= 0x10000; |
| result[2] = x % 0x10000; |
| x -= result[2]; |
| x /= 0x10000; |
| result[1] = x % 0x10000; |
| x -= result[1]; |
| x /= 0x10000; |
| result[0] = x; |
| return result; // Array with 4 elements, each of which is a 16-bit number. |
| } |
| |
| function _addTwo64bitArrays(/* array */ arrayA, /* array */ arrayB) { |
| // summary: |
| // Takes two arrays, each of which holds a 64-bit number broken into 4 |
| // 16-bit elements, and returns a new array that holds a 64-bit number |
| // that is the sum of the two original numbers. |
| // arrayA: An array with 4 elements, each of which is a 16-bit number. |
| // arrayB: An array with 4 elements, each of which is a 16-bit number. |
| dojo.lang.assertType(arrayA, Array); |
| dojo.lang.assertType(arrayB, Array); |
| dojo.lang.assert(arrayA.length == 4); |
| dojo.lang.assert(arrayB.length == 4); |
| |
| var result = new Array(0, 0, 0, 0); |
| result[3] = arrayA[3] + arrayB[3]; |
| result[2] = arrayA[2] + arrayB[2]; |
| result[1] = arrayA[1] + arrayB[1]; |
| result[0] = arrayA[0] + arrayB[0]; |
| _carry(result); |
| return result; // Array with 4 elements, each of which is a 16-bit number. |
| } |
| |
| function _multiplyTwo64bitArrays(/* array */ arrayA, /* array */ arrayB) { |
| // summary: |
| // Takes two arrays, each of which holds a 64-bit number broken into 4 |
| // 16-bit elements, and returns a new array that holds a 64-bit number |
| // that is the product of the two original numbers. |
| // arrayA: An array with 4 elements, each of which is a 16-bit number. |
| // arrayB: An array with 4 elements, each of which is a 16-bit number. |
| dojo.lang.assertType(arrayA, Array); |
| dojo.lang.assertType(arrayB, Array); |
| dojo.lang.assert(arrayA.length == 4); |
| dojo.lang.assert(arrayB.length == 4); |
| |
| var overflow = false; |
| if (arrayA[0] * arrayB[0] !== 0) { overflow = true; } |
| if (arrayA[0] * arrayB[1] !== 0) { overflow = true; } |
| if (arrayA[0] * arrayB[2] !== 0) { overflow = true; } |
| if (arrayA[1] * arrayB[0] !== 0) { overflow = true; } |
| if (arrayA[1] * arrayB[1] !== 0) { overflow = true; } |
| if (arrayA[2] * arrayB[0] !== 0) { overflow = true; } |
| dojo.lang.assert(!overflow); |
| |
| var result = new Array(0, 0, 0, 0); |
| result[0] += arrayA[0] * arrayB[3]; |
| _carry(result); |
| result[0] += arrayA[1] * arrayB[2]; |
| _carry(result); |
| result[0] += arrayA[2] * arrayB[1]; |
| _carry(result); |
| result[0] += arrayA[3] * arrayB[0]; |
| _carry(result); |
| result[1] += arrayA[1] * arrayB[3]; |
| _carry(result); |
| result[1] += arrayA[2] * arrayB[2]; |
| _carry(result); |
| result[1] += arrayA[3] * arrayB[1]; |
| _carry(result); |
| result[2] += arrayA[2] * arrayB[3]; |
| _carry(result); |
| result[2] += arrayA[3] * arrayB[2]; |
| _carry(result); |
| result[3] += arrayA[3] * arrayB[3]; |
| _carry(result); |
| return result; // Array with 4 elements, each of which is a 16-bit number. |
| } |
| |
| function _padWithLeadingZeros(/* string */ string, /* int */ desiredLength) { |
| // summary: |
| // Pads a string with leading zeros and returns the result. |
| // string: A string to add padding to. |
| // desiredLength: The number of characters the return string should have. |
| |
| // examples: |
| // result = _padWithLeadingZeros("abc", 6); |
| // dojo.lang.assert(result == "000abc"); |
| while (string.length < desiredLength) { |
| string = "0" + string; |
| } |
| return string; // string |
| } |
| |
| function _generateRandomEightCharacterHexString() { |
| // summary: |
| // Returns a randomly generated 8-character string of hex digits. |
| |
| // FIXME: This probably isn't a very high quality random number. |
| |
| // 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 eightCharacterString = random32bitNumber.toString(HEX_RADIX); |
| while (eightCharacterString.length < 8) { |
| eightCharacterString = "0" + eightCharacterString; |
| } |
| return eightCharacterString; // String (an 8-character hex string) |
| } |
| |
| function _generateUuidString(/* string? */ node) { |
| // summary: |
| // Generates a time-based UUID, meaning a version 1 UUID. |
| // description: |
| // JavaScript code running in a browser doesn't have access to the |
| // IEEE 802.3 address of the computer, so if a node value isn't |
| // supplied, we generate a random pseudonode value instead. |
| // node: An optional 12-character string to use as the node in the new UUID. |
| dojo.lang.assertType(node, String, {optional: true}); |
| if (node) { |
| dojo.lang.assert(node.length == 12); |
| } else { |
| if (_uniformNode) { |
| node = _uniformNode; |
| } else { |
| if (!_uuidPseudoNodeString) { |
| var pseudoNodeIndicatorBit = 0x8000; |
| var random15bitNumber = Math.floor( (Math.random() % 1) * Math.pow(2, 15) ); |
| var leftmost4HexCharacters = (pseudoNodeIndicatorBit | random15bitNumber).toString(HEX_RADIX); |
| _uuidPseudoNodeString = leftmost4HexCharacters + _generateRandomEightCharacterHexString(); |
| } |
| node = _uuidPseudoNodeString; |
| } |
| } |
| if (!_uuidClockSeqString) { |
| var variantCodeForDCEUuids = 0x8000; // 10--------------, i.e. uses only first two of 16 bits. |
| var random14bitNumber = Math.floor( (Math.random() % 1) * Math.pow(2, 14) ); |
| _uuidClockSeqString = (variantCodeForDCEUuids | random14bitNumber).toString(HEX_RADIX); |
| } |
| |
| // Maybe we should think about trying to make the code more readable to |
| // newcomers by creating a class called "WholeNumber" that encapsulates |
| // the methods and data structures for working with these arrays that |
| // hold 4 16-bit numbers? And then these variables below have names |
| // like "wholeSecondsPerHour" rather than "arraySecondsPerHour"? |
| var now = new Date(); |
| var millisecondsSince1970 = now.valueOf(); // milliseconds since midnight 01 January, 1970 UTC. |
| var nowArray = _get64bitArrayFromFloat(millisecondsSince1970); |
| if (!_cachedMillisecondsBetween1582and1970) { |
| var arraySecondsPerHour = _get64bitArrayFromFloat(60 * 60); |
| var arrayHoursBetween1582and1970 = _get64bitArrayFromFloat(dojo.uuid.TimeBasedGenerator.GREGORIAN_CHANGE_OFFSET_IN_HOURS); |
| var arraySecondsBetween1582and1970 = _multiplyTwo64bitArrays(arrayHoursBetween1582and1970, arraySecondsPerHour); |
| var arrayMillisecondsPerSecond = _get64bitArrayFromFloat(1000); |
| _cachedMillisecondsBetween1582and1970 = _multiplyTwo64bitArrays(arraySecondsBetween1582and1970, arrayMillisecondsPerSecond); |
| _cachedHundredNanosecondIntervalsPerMillisecond = _get64bitArrayFromFloat(10000); |
| } |
| var arrayMillisecondsSince1970 = nowArray; |
| var arrayMillisecondsSince1582 = _addTwo64bitArrays(_cachedMillisecondsBetween1582and1970, arrayMillisecondsSince1970); |
| var arrayHundredNanosecondIntervalsSince1582 = _multiplyTwo64bitArrays(arrayMillisecondsSince1582, _cachedHundredNanosecondIntervalsPerMillisecond); |
| |
| if (now.valueOf() == _dateValueOfPreviousUuid) { |
| arrayHundredNanosecondIntervalsSince1582[3] += _nextIntraMillisecondIncrement; |
| _carry(arrayHundredNanosecondIntervalsSince1582); |
| _nextIntraMillisecondIncrement += 1; |
| if (_nextIntraMillisecondIncrement == 10000) { |
| // If we've gotten to here, it means we've already generated 10,000 |
| // UUIDs in this single millisecond, which is the most that the UUID |
| // timestamp field allows for. So now we'll just sit here and wait |
| // for a fraction of a millisecond, so as to ensure that the next |
| // time this method is called there will be a different millisecond |
| // value in the timestamp field. |
| while (now.valueOf() == _dateValueOfPreviousUuid) { |
| now = new Date(); |
| } |
| } |
| } else { |
| _dateValueOfPreviousUuid = now.valueOf(); |
| _nextIntraMillisecondIncrement = 1; |
| } |
| |
| var hexTimeLowLeftHalf = arrayHundredNanosecondIntervalsSince1582[2].toString(HEX_RADIX); |
| var hexTimeLowRightHalf = arrayHundredNanosecondIntervalsSince1582[3].toString(HEX_RADIX); |
| var hexTimeLow = _padWithLeadingZeros(hexTimeLowLeftHalf, 4) + _padWithLeadingZeros(hexTimeLowRightHalf, 4); |
| var hexTimeMid = arrayHundredNanosecondIntervalsSince1582[1].toString(HEX_RADIX); |
| hexTimeMid = _padWithLeadingZeros(hexTimeMid, 4); |
| var hexTimeHigh = arrayHundredNanosecondIntervalsSince1582[0].toString(HEX_RADIX); |
| hexTimeHigh = _padWithLeadingZeros(hexTimeHigh, 3); |
| var hyphen = "-"; |
| var versionCodeForTimeBasedUuids = "1"; // binary2hex("0001") |
| var resultUuid = hexTimeLow + hyphen + hexTimeMid + hyphen + |
| versionCodeForTimeBasedUuids + hexTimeHigh + hyphen + |
| _uuidClockSeqString + hyphen + node; |
| resultUuid = resultUuid.toLowerCase(); |
| return resultUuid; // String (a 36 character string, which will look something like "b4308fb0-86cd-11da-a72b-0800200c9a66") |
| } |
| |
| this.setNode = function(/* string? */ node) { |
| // summary: |
| // Sets the 'node' value that will be included in generated UUIDs. |
| // node: A 12-character hex string representing a pseudoNode or hardwareNode. |
| dojo.lang.assert((node === null) || (node.length == 12)); |
| _uniformNode = node; |
| }; |
| |
| this.getNode = function() { |
| // summary: |
| // Returns the 'node' value that will be included in generated UUIDs. |
| return _uniformNode; // String (a 12-character hex string representing a pseudoNode or hardwareNode) |
| }; |
| |
| this.generate = function(/* misc? */ input) { |
| // summary: |
| // This function generates time-based UUIDs, meaning "version 1" UUIDs. |
| // description: |
| // For more info, see |
| // http://www.webdav.org/specs/draft-leach-uuids-guids-01.txt |
| // http://www.infonuovo.com/dma/csdocs/sketch/instidid.htm |
| // http://kruithof.xs4all.nl/uuid/uuidgen |
| // http://www.opengroup.org/onlinepubs/009629399/apdxa.htm#tagcjh_20 |
| // http://jakarta.apache.org/commons/sandbox/id/apidocs/org/apache/commons/id/uuid/clock/Clock.html |
| |
| // examples: |
| // var generate = dojo.uuid.TimeBasedGenerator.generate; |
| // var uuid; // an instance of dojo.uuid.Uuid |
| // var string; // a simple string literal |
| // string = generate(); |
| // string = generate(String); |
| // uuid = generate(dojo.uuid.Uuid); |
| // string = generate("017bf397618a"); |
| // string = generate({node: "017bf397618a"}); // hardwareNode |
| // string = generate({node: "f17bf397618a"}); // pseudoNode |
| // string = generate({hardwareNode: "017bf397618a"}); |
| // string = generate({pseudoNode: "f17bf397618a"}); |
| // string = generate({node: "017bf397618a", returnType: String}); |
| // uuid = generate({node: "017bf397618a", returnType: dojo.uuid.Uuid}); |
| // dojo.uuid.TimeBasedGenerator.setNode("017bf397618a"); |
| // string = generate(); // the generated UUID has node == "017bf397618a" |
| // uuid = generate(dojo.uuid.Uuid); // the generated UUID has node == "017bf397618a" |
| var nodeString = null; |
| var returnType = null; |
| |
| if (input) { |
| if (dojo.lang.isObject(input) && !dojo.lang.isBuiltIn(input)) { |
| // input: object {node: string, hardwareNode: string, pseudoNode: string} |
| // node: A 12-character hex string representing a pseudoNode or hardwareNode. |
| // hardwareNode: A 12-character hex string containing an IEEE 802.3 network node identificator. |
| // pseudoNode: A 12-character hex string representing a pseudoNode. |
| var namedParameters = input; |
| dojo.lang.assertValidKeywords(namedParameters, ["node", "hardwareNode", "pseudoNode", "returnType"]); |
| var node = namedParameters["node"]; |
| var hardwareNode = namedParameters["hardwareNode"]; |
| var pseudoNode = namedParameters["pseudoNode"]; |
| nodeString = (node || pseudoNode || hardwareNode); |
| if (nodeString) { |
| var firstCharacter = nodeString.charAt(0); |
| var firstDigit = parseInt(firstCharacter, HEX_RADIX); |
| if (hardwareNode) { |
| dojo.lang.assert((firstDigit >= 0x0) && (firstDigit <= 0x7)); |
| } |
| if (pseudoNode) { |
| dojo.lang.assert((firstDigit >= 0x8) && (firstDigit <= 0xF)); |
| } |
| } |
| returnType = namedParameters["returnType"]; |
| dojo.lang.assertType(returnType, Function, {optional: true}); |
| } else { |
| if (dojo.lang.isString(input)) { |
| // input: string A 12-character hex string representing a pseudoNode or hardwareNode. |
| nodeString = input; |
| returnType = null; |
| } else { |
| if (dojo.lang.isFunction(input)) { |
| // input: constructor The type of object to return. Usually String or dojo.uuid.Uuid |
| nodeString = null; |
| returnType = input; |
| } |
| } |
| } |
| if (nodeString) { |
| dojo.lang.assert(nodeString.length == 12); |
| var integer = parseInt(nodeString, HEX_RADIX); |
| dojo.lang.assert(isFinite(integer)); |
| } |
| dojo.lang.assertType(returnType, Function, {optional: true}); |
| } |
| |
| var uuidString = _generateUuidString(nodeString); |
| var returnValue; |
| if (returnType && (returnType != String)) { |
| returnValue = new returnType(uuidString); |
| } else { |
| returnValue = uuidString; |
| } |
| return returnValue; // object |
| }; |
| }(); |