📄 timebasedgenerator.js
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/*
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 () {
this.GREGORIAN_CHANGE_OFFSET_IN_HOURS = 3394248;
var _uuidPseudoNodeString = null;
var _uuidClockSeqString = null;
var _dateValueOfPreviousUuid = null;
var _nextIntraMillisecondIncrement = 0;
var _cachedMillisecondsBetween1582and1970 = null;
var _cachedHundredNanosecondIntervalsPerMillisecond = null;
var _uniformNode = null;
var HEX_RADIX = 16;
function _carry(arrayA) {
arrayA[2] += arrayA[3] >>> 16;
arrayA[3] &= 65535;
arrayA[1] += arrayA[2] >>> 16;
arrayA[2] &= 65535;
arrayA[0] += arrayA[1] >>> 16;
arrayA[1] &= 65535;
dojo.lang.assert((arrayA[0] >>> 16) === 0);
}
function _get64bitArrayFromFloat(x) {
var result = new Array(0, 0, 0, 0);
result[3] = x % 65536;
x -= result[3];
x /= 65536;
result[2] = x % 65536;
x -= result[2];
x /= 65536;
result[1] = x % 65536;
x -= result[1];
x /= 65536;
result[0] = x;
return result;
}
function _addTwo64bitArrays(arrayA, arrayB) {
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;
}
function _multiplyTwo64bitArrays(arrayA, arrayB) {
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;
}
function _padWithLeadingZeros(string, desiredLength) {
while (string.length < desiredLength) {
string = "0" + string;
}
return string;
}
function _generateRandomEightCharacterHexString() {
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;
}
function _generateUuidString(node) {
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 = 32768;
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 = 32768;
var random14bitNumber = Math.floor((Math.random() % 1) * Math.pow(2, 14));
_uuidClockSeqString = (variantCodeForDCEUuids | random14bitNumber).toString(HEX_RADIX);
}
var now = new Date();
var millisecondsSince1970 = now.valueOf();
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) {
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";
var resultUuid = hexTimeLow + hyphen + hexTimeMid + hyphen + versionCodeForTimeBasedUuids + hexTimeHigh + hyphen + _uuidClockSeqString + hyphen + node;
resultUuid = resultUuid.toLowerCase();
return resultUuid;
}
this.setNode = function (node) {
dojo.lang.assert((node === null) || (node.length == 12));
_uniformNode = node;
};
this.getNode = function () {
return _uniformNode;
};
this.generate = function (input) {
var nodeString = null;
var returnType = null;
if (input) {
if (dojo.lang.isObject(input) && !dojo.lang.isBuiltIn(input)) {
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 >= 0) && (firstDigit <= 7));
}
if (pseudoNode) {
dojo.lang.assert((firstDigit >= 8) && (firstDigit <= 15));
}
}
returnType = namedParameters["returnType"];
dojo.lang.assertType(returnType, Function, {optional:true});
} else {
if (dojo.lang.isString(input)) {
nodeString = input;
returnType = null;
} else {
if (dojo.lang.isFunction(input)) {
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;
};
}();
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