New file |
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) |
}; |
|
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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 |
} |
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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) |
} |
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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") |
} |
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}(); |
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} |