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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;
        };
}();