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Diffstat (limited to 'includes/js/dojox/uuid/generateTimeBasedUuid.js')
| -rw-r--r-- | includes/js/dojox/uuid/generateTimeBasedUuid.js | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/includes/js/dojox/uuid/generateTimeBasedUuid.js b/includes/js/dojox/uuid/generateTimeBasedUuid.js new file mode 100644 index 0000000..20be9f4 --- /dev/null +++ b/includes/js/dojox/uuid/generateTimeBasedUuid.js @@ -0,0 +1,290 @@ +if(!dojo._hasResource["dojox.uuid.generateTimeBasedUuid"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code. +dojo._hasResource["dojox.uuid.generateTimeBasedUuid"] = true; +dojo.provide("dojox.uuid.generateTimeBasedUuid"); + +dojox.uuid.generateTimeBasedUuid = function(/*String?*/ node){ + // 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 + // node: + // A 12-character hex string representing either a pseudo-node or + // hardware-node (an IEEE 802.3 network node). A hardware-node + // will be something like "017bf397618a", always with the first bit + // being 0. A pseudo-node will be something like "f17bf397618a", + // always with the first bit being 1. + // examples: + // string = dojox.uuid.generateTimeBasedUuid(); + // string = dojox.uuid.generateTimeBasedUuid("017bf397618a"); + // dojox.uuid.generateTimeBasedUuid.setNode("017bf397618a"); + // string = dojox.uuid.generateTimeBasedUuid(); // the generated UUID has node == "017bf397618a" + var uuidString = dojox.uuid.generateTimeBasedUuid._generator.generateUuidString(node); + return uuidString; // String +}; + +dojox.uuid.generateTimeBasedUuid.isValidNode = function(/*String?*/ node){ + var HEX_RADIX = 16; + var integer = parseInt(node, HEX_RADIX); + var valid = dojo.isString(node) && node.length == 12 && isFinite(integer); + return valid; // Boolean +}; + +dojox.uuid.generateTimeBasedUuid.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. + dojox.uuid.assert((node === null) || this.isValidNode(node)); + this._uniformNode = node; +}; + +dojox.uuid.generateTimeBasedUuid.getNode = function(){ + // summary: + // Returns the 'node' value that will be included in generated UUIDs. + return this._uniformNode; // String (a 12-character hex string representing a pseudoNode or hardwareNode) +}; + + +dojox.uuid.generateTimeBasedUuid._generator = new function(){ + // 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: + // dojox.uuid.generateTimeBasedUuid.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; + + // -------------------------------------------------- + // 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; + dojox.uuid.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. + dojox.uuid.assert(dojo.isArray(arrayA)); + dojox.uuid.assert(dojo.isArray(arrayB)); + dojox.uuid.assert(arrayA.length == 4); + dojox.uuid.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. + dojox.uuid.assert(dojo.isArray(arrayA)); + dojox.uuid.assert(dojo.isArray(arrayB)); + dojox.uuid.assert(arrayA.length == 4); + dojox.uuid.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; } + dojox.uuid.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); + // dojox.uuid.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) + } + + this.generateUuidString = function(/*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. + if(node){ + dojox.uuid.assert(dojox.uuid.generateTimeBasedUuid.isValidNode(node)); + }else{ + if(dojox.uuid.generateTimeBasedUuid._uniformNode){ + node = dojox.uuid.generateTimeBasedUuid._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(dojox.uuid.generateTimeBasedUuid._generator.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") + } + +}(); + +} |