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GlobalIdGenerator.php
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1 <?php
21 namespace Wikimedia\UUID;
22 
23 use InvalidArgumentException;
24 use RuntimeException;
25 use Wikimedia\Assert\Assert;
26 use Wikimedia\AtEase\AtEase;
27 use Wikimedia\Timestamp\ConvertibleTimestamp;
28 
36  protected $shellCallback;
37 
39  protected $tmpDir;
44  protected $uniqueFilePrefix;
46  protected $nodeIdFile;
48  protected $nodeId32;
50  protected $nodeId48;
51 
53  protected $loaded = false;
55  protected $lockFile88;
57  protected $lockFile128;
59  protected $lockFileUUID;
60 
62  protected $fileHandles = [];
63 
65  public const QUICK_VOLATILE = 1;
66 
71  private const FILE_PREFIX = 'mw-GlobalIdGenerator';
72 
74  private const CLOCK_TIME = 'time';
76  private const CLOCK_COUNTER = 'counter';
78  private const CLOCK_SEQUENCE = 'clkSeq';
80  private const CLOCK_OFFSET = 'offset';
82  private const CLOCK_OFFSET_COUNTER = 'offsetCounter';
83 
88  public function __construct( $tempDirectory, $shellCallback ) {
89  if ( func_num_args() >= 3 && !is_callable( $shellCallback ) ) {
90  trigger_error(
91  __CLASS__ . ' with a BagOStuff instance was deprecated in MediaWiki 1.37.',
92  E_USER_DEPRECATED
93  );
94  $shellCallback = func_get_arg( 2 );
95  }
96  if ( !strlen( $tempDirectory ) ) {
97  throw new InvalidArgumentException( "No temp directory provided" );
98  }
99  $this->tmpDir = $tempDirectory;
100  // Check if getmyuid exists, it could be disabled for security reasons - T324513
101  $fileSuffix = function_exists( 'getmyuid' ) ? getmyuid() : '';
102  $this->uniqueFilePrefix = self::FILE_PREFIX . $fileSuffix;
103  $this->nodeIdFile = $tempDirectory . '/' . $this->uniqueFilePrefix . '-UID-nodeid';
104  // If different processes run as different users, they may have different temp dirs.
105  // This is dealt with by initializing the clock sequence number and counters randomly.
106  $this->lockFile88 = $tempDirectory . '/' . $this->uniqueFilePrefix . '-UID-88';
107  $this->lockFile128 = $tempDirectory . '/' . $this->uniqueFilePrefix . '-UID-128';
108  $this->lockFileUUID = $tempDirectory . '/' . $this->uniqueFilePrefix . '-UUID-128';
109 
110  $this->shellCallback = $shellCallback;
111  }
112 
128  public function newTimestampedUID88( int $base = 10 ) {
129  Assert::parameter( $base <= 36, '$base', 'must be <= 36' );
130  Assert::parameter( $base >= 2, '$base', 'must be >= 2' );
131 
132  $info = $this->getTimeAndDelay( 'lockFile88', 1, 1024, 1024 );
133  $info[self::CLOCK_OFFSET_COUNTER] %= 1024;
134 
135  return \Wikimedia\base_convert( $this->getTimestampedID88( $info ), 2, $base );
136  }
137 
143  protected function getTimestampedID88( array $info ) {
144  $time = $info[self::CLOCK_TIME];
145  $counter = $info[self::CLOCK_OFFSET_COUNTER];
146  // Take the 46 LSBs of "milliseconds since epoch"
147  $id_bin = $this->millisecondsSinceEpochBinary( $time );
148  // Add a 10 bit counter resulting in 56 bits total
149  $id_bin .= str_pad( decbin( $counter ), 10, '0', STR_PAD_LEFT );
150  // Add the 32 bit node ID resulting in 88 bits total
151  $id_bin .= $this->getNodeId32();
152  // Convert to a 1-27 digit integer string
153  if ( strlen( $id_bin ) !== 88 ) {
154  throw new RuntimeException( "Detected overflow for millisecond timestamp." );
155  }
156 
157  return $id_bin;
158  }
159 
174  public function newTimestampedUID128( int $base = 10 ) {
175  Assert::parameter( $base <= 36, '$base', 'must be <= 36' );
176  Assert::parameter( $base >= 2, '$base', 'must be >= 2' );
177 
178  $info = $this->getTimeAndDelay( 'lockFile128', 16384, 1048576, 1048576 );
179  $info[self::CLOCK_OFFSET_COUNTER] %= 1048576;
180 
181  return \Wikimedia\base_convert( $this->getTimestampedID128( $info ), 2, $base );
182  }
183 
189  protected function getTimestampedID128( array $info ) {
190  $time = $info[self::CLOCK_TIME];
191  $counter = $info[self::CLOCK_OFFSET_COUNTER];
192  $clkSeq = $info[self::CLOCK_SEQUENCE];
193  // Take the 46 LSBs of "milliseconds since epoch"
194  $id_bin = $this->millisecondsSinceEpochBinary( $time );
195  // Add a 20 bit counter resulting in 66 bits total
196  $id_bin .= str_pad( decbin( $counter ), 20, '0', STR_PAD_LEFT );
197  // Add a 14 bit clock sequence number resulting in 80 bits total
198  $id_bin .= str_pad( decbin( $clkSeq ), 14, '0', STR_PAD_LEFT );
199  // Add the 48 bit node ID resulting in 128 bits total
200  $id_bin .= $this->getNodeId48();
201  // Convert to a 1-39 digit integer string
202  if ( strlen( $id_bin ) !== 128 ) {
203  throw new RuntimeException( "Detected overflow for millisecond timestamp." );
204  }
205 
206  return $id_bin;
207  }
208 
215  public function newUUIDv1() {
216  // There can be up to 10000 intervals for the same millisecond timestamp.
217  // [0,4999] counter + [0,5000] offset is in [0,9999] for the offset counter.
218  // Add this onto the timestamp to allow making up to 5000 IDs per second.
219  return $this->getUUIDv1( $this->getTimeAndDelay( 'lockFileUUID', 16384, 5000, 5001 ) );
220  }
221 
226  protected function getUUIDv1( array $info ) {
227  $clkSeq_bin = \Wikimedia\base_convert( $info[self::CLOCK_SEQUENCE], 10, 2, 14 );
228  $time_bin = $this->intervalsSinceGregorianBinary(
229  $info[self::CLOCK_TIME],
230  $info[self::CLOCK_OFFSET_COUNTER]
231  );
232  // Take the 32 bits of "time low"
233  $id_bin = substr( $time_bin, 28, 32 );
234  // Add 16 bits of "time mid" resulting in 48 bits total
235  $id_bin .= substr( $time_bin, 12, 16 );
236  // Add 4 bit version resulting in 52 bits total
237  $id_bin .= '0001';
238  // Add 12 bits of "time high" resulting in 64 bits total
239  $id_bin .= substr( $time_bin, 0, 12 );
240  // Add 2 bits of "variant" resulting in 66 bits total
241  $id_bin .= '10';
242  // Add 6 bits of "clock seq high" resulting in 72 bits total
243  $id_bin .= substr( $clkSeq_bin, 0, 6 );
244  // Add 8 bits of "clock seq low" resulting in 80 bits total
245  $id_bin .= substr( $clkSeq_bin, 6, 8 );
246  // Add the 48 bit node ID resulting in 128 bits total
247  $id_bin .= $this->getNodeId48();
248  // Convert to a 32 char hex string with dashes
249  if ( strlen( $id_bin ) !== 128 ) {
250  throw new RuntimeException( "Detected overflow for millisecond timestamp." );
251  }
252  $hex = \Wikimedia\base_convert( $id_bin, 2, 16, 32 );
253  return sprintf( '%s-%s-%s-%s-%s',
254  // "time_low" (32 bits)
255  substr( $hex, 0, 8 ),
256  // "time_mid" (16 bits)
257  substr( $hex, 8, 4 ),
258  // "time_hi_and_version" (16 bits)
259  substr( $hex, 12, 4 ),
260  // "clk_seq_hi_res" (8 bits) and "clk_seq_low" (8 bits)
261  substr( $hex, 16, 4 ),
262  // "node" (48 bits)
263  substr( $hex, 20, 12 )
264  );
265  }
266 
273  public function newRawUUIDv1() {
274  return str_replace( '-', '', $this->newUUIDv1() );
275  }
276 
283  public function newUUIDv4() {
284  $hex = bin2hex( random_bytes( 32 / 2 ) );
285 
286  return sprintf( '%s-%s-%s-%s-%s',
287  // "time_low" (32 bits)
288  substr( $hex, 0, 8 ),
289  // "time_mid" (16 bits)
290  substr( $hex, 8, 4 ),
291  // "time_hi_and_version" (16 bits)
292  '4' . substr( $hex, 12, 3 ),
293  // "clk_seq_hi_res" (8 bits, variant is binary 10x) and "clk_seq_low" (8 bits)
294  dechex( 0x8 | ( hexdec( $hex[15] ) & 0x3 ) ) . $hex[16] . substr( $hex, 17, 2 ),
295  // "node" (48 bits)
296  substr( $hex, 19, 12 )
297  );
298  }
299 
306  public function newRawUUIDv4() {
307  return str_replace( '-', '', $this->newUUIDv4() );
308  }
309 
322  public function newSequentialPerNodeID( $bucket, $bits = 48, $flags = 0 ) {
323  return current( $this->newSequentialPerNodeIDs( $bucket, $bits, 1, $flags ) );
324  }
325 
336  public function newSequentialPerNodeIDs( $bucket, $bits, $count, $flags = 0 ) {
337  return $this->getSequentialPerNodeIDs( $bucket, $bits, $count, $flags );
338  }
339 
347  public function getTimestampFromUUIDv1( string $uuid, int $format = TS_MW ) {
348  $components = [];
349  if ( !preg_match(
350  '/^([0-9a-f]{8})-([0-9a-f]{4})-(1[0-9a-f]{3})-([89ab][0-9a-f]{3})-([0-9a-f]{12})$/',
351  $uuid,
352  $components
353  ) ) {
354  throw new InvalidArgumentException( "Invalid UUIDv1 {$uuid}" );
355  }
356 
357  $timestamp = hexdec( substr( $components[3], 1 ) . $components[2] . $components[1] );
358  // The 60 bit timestamp value is constructed from fields of this UUID.
359  // The timestamp is measured in 100-nanosecond units since midnight, October 15, 1582 UTC.
360  $unixTime = ( $timestamp - 0x01b21dd213814000 ) / 1e7;
361 
362  return ConvertibleTimestamp::convert( $format, $unixTime );
363  }
364 
376  protected function getSequentialPerNodeIDs( $bucket, $bits, $count, $flags ) {
377  if ( $count <= 0 ) {
378  return [];
379  }
380  if ( $bits < 16 || $bits > 48 ) {
381  throw new RuntimeException( "Requested bit size ($bits) is out of range." );
382  }
383 
384  $path = $this->tmpDir . '/' . $this->uniqueFilePrefix . '-' . rawurlencode( $bucket ) . '-48';
385  // Get the UID lock file handle
386  if ( isset( $this->fileHandles[$path] ) ) {
387  $handle = $this->fileHandles[$path];
388  } else {
389  $handle = fopen( $path, 'cb+' );
390  $this->fileHandles[$path] = $handle ?: null;
391  }
392  // Acquire the UID lock file
393  if ( $handle === false ) {
394  throw new RuntimeException( "Could not open '{$path}'." );
395  }
396  if ( !flock( $handle, LOCK_EX ) ) {
397  fclose( $handle );
398  throw new RuntimeException( "Could not acquire '{$path}'." );
399  }
400  // Fetch the counter value and increment it...
401  rewind( $handle );
402 
403  // fetch as float
404  $counter = floor( (float)trim( fgets( $handle ) ) ) + $count;
405 
406  // Write back the new counter value
407  ftruncate( $handle, 0 );
408  rewind( $handle );
409 
410  // Use fmod() to avoid "division by zero" on 32 bit machines
411  // warp-around as needed
412  fwrite( $handle, (string)fmod( $counter, 2 ** 48 ) );
413  fflush( $handle );
414 
415  // Release the UID lock file
416  flock( $handle, LOCK_UN );
417 
418  $ids = [];
419  $divisor = 2 ** $bits;
420 
421  // pre-increment counter value
422  $currentId = floor( $counter - $count );
423  for ( $i = 0; $i < $count; ++$i ) {
424  // Use fmod() to avoid "division by zero" on 32 bit machines
425  $ids[] = fmod( ++$currentId, $divisor );
426  }
427 
428  return $ids;
429  }
430 
448  protected function getTimeAndDelay( $lockFile, $clockSeqSize, $counterSize, $offsetSize ) {
449  // Get the UID lock file handle
450  if ( isset( $this->fileHandles[$this->$lockFile] ) ) {
451  $handle = $this->fileHandles[$this->$lockFile];
452  } else {
453  $handle = fopen( $this->$lockFile, 'cb+' );
454  $this->fileHandles[$this->$lockFile] = $handle ?: null;
455  }
456  // Acquire the UID lock file
457  if ( $handle === false ) {
458  throw new RuntimeException( "Could not open '{$this->$lockFile}'." );
459  }
460  if ( !flock( $handle, LOCK_EX ) ) {
461  fclose( $handle );
462  throw new RuntimeException( "Could not acquire '{$this->$lockFile}'." );
463  }
464 
465  // The formatters that use this method expect a timestamp with millisecond
466  // precision and a counter upto a certain size. When more IDs than the counter
467  // size are generated during the same timestamp, an exception is thrown as we
468  // cannot increment further, because the formatted ID would not have enough
469  // bits to fit the counter.
470  //
471  // To orchestrate this between independent PHP processes on the same host,
472  // we must have a common sense of time so that we only have to maintain
473  // a single counter in a single lock file.
474  //
475  // Given that:
476  // * The system clock can be observed via time(), without milliseconds.
477  // * Some other clock can be observed via microtime(), which also offers
478  // millisecond precision.
479  // * microtime() drifts in-process further and further away from the system
480  // clock the longer a process runs for.
481  // For example, on 2018-10-03 an HHVM 3.18 JobQueue process at WMF,
482  // that ran for 9 min 55 sec, microtime drifted by 7 seconds.
483  // time() does not have this problem. See https://bugs.php.net/bug.php?id=42659.
484  //
485  // We have two choices:
486  //
487  // 1. Use microtime() with the following caveats:
488  // - The last stored time may be in the future, or our current time may be in the
489  // past, in which case we'll frequently enter the slow timeWaitUntil() method to
490  // try and "sync" the current process with the previous process.
491  // We mustn't block for long though, max 10ms?
492  // - For any drift above 10ms, we pretend that the clock went backwards, and treat
493  // it the same way as after an NTP sync, by incrementing clock sequence instead.
494  // Given the sequence rolls over automatically, and silently, and is meant to be
495  // rare, this is essentially sacrifices a reasonable guarantee of uniqueness.
496  // - For long running processes (e.g. longer than a few seconds) the drift can
497  // easily be more than 2 seconds. Because we only have a single lock file
498  // and don't want to keep too many counters and deal with clearing those,
499  // we fatal the user and refuse to make an ID. (T94522)
500  // - This offers terrible service availability.
501  // 2. Use time() instead, and expand the counter size by 1000x and use its
502  // digits as if they were the millisecond fraction of our timestamp.
503  // Known caveats or perf impact: None. We still need to read-write our
504  // lock file on each generation, so might as well make the most of it.
505  //
506  // We choose the latter.
507  $msecCounterSize = $counterSize * 1000;
508 
509  rewind( $handle );
510  // Format of lock file contents:
511  // "<clk seq> <sec> <msec counter> <rand offset>"
512  $data = explode( ' ', fgets( $handle ) );
513 
514  if ( count( $data ) === 4 ) {
515  // The UID lock file was already initialized
516  $clkSeq = (int)$data[0] % $clockSeqSize;
517  $prevSec = (int)$data[1];
518  // Counter for UIDs with the same timestamp,
519  $msecCounter = 0;
520  $randOffset = (int)$data[3] % $counterSize;
521 
522  // If the system clock moved backwards by an NTP sync,
523  // or if the last writer process had its clock drift ahead,
524  // Try to catch up if the gap is small, so that we can keep a single
525  // monotonic logic file.
526  $sec = $this->timeWaitUntil( $prevSec );
527  if ( $sec === false ) {
528  // Gap is too big. Looks like the clock got moved back significantly.
529  // Start a new clock sequence, and re-randomize the extra offset,
530  // which is useful for UIDs that do not include the clock sequence number.
531  $clkSeq = ( $clkSeq + 1 ) % $clockSeqSize;
532  $sec = time();
533  $randOffset = mt_rand( 0, $offsetSize - 1 );
534  trigger_error( "Clock was set back; sequence number incremented." );
535  } elseif ( $sec === $prevSec ) {
536  // Double check, only keep remainder if a previous writer wrote
537  // something here that we don't accept.
538  $msecCounter = (int)$data[2] % $msecCounterSize;
539  // Bump the counter if the time has not changed yet
540  if ( ++$msecCounter >= $msecCounterSize ) {
541  // More IDs generated with the same time than counterSize can accommodate
542  flock( $handle, LOCK_UN );
543  throw new RuntimeException( "Counter overflow for timestamp value." );
544  }
545  }
546  } else {
547  // Initialize UID lock file information
548  $clkSeq = mt_rand( 0, $clockSeqSize - 1 );
549  $sec = time();
550  $msecCounter = 0;
551  $randOffset = mt_rand( 0, $offsetSize - 1 );
552  }
553 
554  // Update and release the UID lock file
555  ftruncate( $handle, 0 );
556  rewind( $handle );
557  fwrite( $handle, "{$clkSeq} {$sec} {$msecCounter} {$randOffset}" );
558  fflush( $handle );
559  flock( $handle, LOCK_UN );
560 
561  // Split msecCounter back into msec and counter
562  $msec = (int)( $msecCounter / 1000 );
563  $counter = $msecCounter % 1000;
564 
565  return [
566  self::CLOCK_TIME => [ $sec, $msec ],
567  self::CLOCK_COUNTER => $counter,
568  self::CLOCK_SEQUENCE => $clkSeq,
569  self::CLOCK_OFFSET => $randOffset,
570  self::CLOCK_OFFSET_COUNTER => $counter + $randOffset,
571  ];
572  }
573 
581  protected function timeWaitUntil( $time ) {
582  $start = microtime( true );
583  do {
584  $ct = time();
585  // https://www.php.net/manual/en/language.operators.comparison.php
586  if ( $ct >= $time ) {
587  // current time is higher than or equal to than $time
588  return $ct;
589  }
590  // up to 10ms
591  } while ( ( microtime( true ) - $start ) <= 0.010 );
592 
593  return false;
594  }
595 
601  protected function millisecondsSinceEpochBinary( array $time ) {
602  [ $sec, $msec ] = $time;
603  $ts = 1000 * $sec + $msec;
604  if ( $ts > 2 ** 52 ) {
605  throw new RuntimeException( __METHOD__ .
606  ': sorry, this function doesn\'t work after the year 144680' );
607  }
608 
609  return substr( \Wikimedia\base_convert( (string)$ts, 10, 2, 46 ), -46 );
610  }
611 
618  protected function intervalsSinceGregorianBinary( array $time, $delta = 0 ) {
619  [ $sec, $msec ] = $time;
620  $offset = '122192928000000000';
621 
622  // 64 bit integers
623  if ( PHP_INT_SIZE >= 8 ) {
624  $ts = ( 1000 * $sec + $msec ) * 10000 + (int)$offset + $delta;
625  $id_bin = str_pad( decbin( $ts % ( 2 ** 60 ) ), 60, '0', STR_PAD_LEFT );
626  } elseif ( extension_loaded( 'gmp' ) ) {
627  // ms
628  $ts = gmp_add( gmp_mul( (string)$sec, '1000' ), (string)$msec );
629  // 100ns intervals
630  $ts = gmp_add( gmp_mul( $ts, '10000' ), $offset );
631  $ts = gmp_add( $ts, (string)$delta );
632  // wrap around
633  $ts = gmp_mod( $ts, gmp_pow( '2', 60 ) );
634  $id_bin = str_pad( gmp_strval( $ts, 2 ), 60, '0', STR_PAD_LEFT );
635  } elseif ( extension_loaded( 'bcmath' ) ) {
636  // ms
637  $ts = bcadd( bcmul( $sec, '1000' ), $msec );
638  // 100ns intervals
639  $ts = bcadd( bcmul( $ts, '10000' ), $offset );
640  $ts = bcadd( $ts, (string)$delta );
641  // wrap around
642  $ts = bcmod( $ts, bcpow( '2', '60' ) );
643  $id_bin = \Wikimedia\base_convert( $ts, 10, 2, 60 );
644  } else {
645  throw new RuntimeException( 'bcmath or gmp extension required for 32 bit machines.' );
646  }
647  return $id_bin;
648  }
649 
653  private function load() {
654  if ( $this->loaded ) {
655  return;
656  }
657 
658  $this->loaded = true;
659 
660  $nodeId = '';
661  if ( is_file( $this->nodeIdFile ) ) {
662  $nodeId = file_get_contents( $this->nodeIdFile );
663  }
664  // Try to get some ID that uniquely identifies this machine (RFC 4122)...
665  if ( !preg_match( '/^[0-9a-f]{12}$/i', $nodeId ) ) {
666  AtEase::suppressWarnings();
667  if ( PHP_OS_FAMILY === 'Windows' ) {
668  // https://technet.microsoft.com/en-us/library/bb490913.aspx
669  $csv = trim( ( $this->shellCallback )( 'getmac /NH /FO CSV' ) );
670  $line = substr( $csv, 0, strcspn( $csv, "\n" ) );
671  $info = str_getcsv( $line );
672  // @phan-suppress-next-line PhanTypeMismatchArgumentNullableInternal False positive
673  $nodeId = isset( $info[0] ) ? str_replace( '-', '', $info[0] ) : '';
674  } elseif ( is_executable( '/sbin/ifconfig' ) ) {
675  // Linux/BSD/Solaris/OS X
676  // See https://linux.die.net/man/8/ifconfig
677  $m = [];
678  preg_match( '/\s([0-9a-f]{2}(?::[0-9a-f]{2}){5})\s/',
679  ( $this->shellCallback )( '/sbin/ifconfig -a' ), $m );
680  $nodeId = isset( $m[1] ) ? str_replace( ':', '', $m[1] ) : '';
681  }
682  AtEase::restoreWarnings();
683  if ( !preg_match( '/^[0-9a-f]{12}$/i', $nodeId ) ) {
684  $nodeId = bin2hex( random_bytes( 12 / 2 ) );
685  // set multicast bit
686  $nodeId[1] = dechex( hexdec( $nodeId[1] ) | 0x1 );
687  }
688  file_put_contents( $this->nodeIdFile, $nodeId );
689  }
690  $this->nodeId32 = \Wikimedia\base_convert( substr( sha1( $nodeId ), 0, 8 ), 16, 2, 32 );
691  $this->nodeId48 = \Wikimedia\base_convert( $nodeId, 16, 2, 48 );
692  }
693 
697  private function getNodeId32() {
698  $this->load();
699 
700  return $this->nodeId32;
701  }
702 
706  private function getNodeId48() {
707  $this->load();
708 
709  return $this->nodeId48;
710  }
711 
723  private function deleteCacheFiles() {
724  foreach ( $this->fileHandles as $path => $handle ) {
725  if ( $handle !== null ) {
726  fclose( $handle );
727  }
728  if ( is_file( $path ) ) {
729  unlink( $path );
730  }
731  unset( $this->fileHandles[$path] );
732  }
733  if ( is_file( $this->nodeIdFile ) ) {
734  unlink( $this->nodeIdFile );
735  }
736  }
737 
750  public function unitTestTearDown() {
751  $this->deleteCacheFiles();
752  }
753 
754  public function __destruct() {
755  // @phan-suppress-next-line PhanPluginUseReturnValueInternalKnown
756  array_map( 'fclose', array_filter( $this->fileHandles ) );
757  }
758 }
Class for getting statistically unique IDs without a central coordinator.
newRawUUIDv1()
Return an RFC4122 compliant v1 UUID.
newTimestampedUID88(int $base=10)
Get a statistically unique 88-bit unsigned integer ID string.
newSequentialPerNodeID( $bucket, $bits=48, $flags=0)
Return an ID that is sequential only for this node and bucket.
newTimestampedUID128(int $base=10)
Get a statistically unique 128-bit unsigned integer ID string.
newUUIDv4()
Return an RFC4122 compliant v4 UUID.
getSequentialPerNodeIDs( $bucket, $bits, $count, $flags)
Return IDs that are sequential only for this node and bucket.
newRawUUIDv4()
Return an RFC4122 compliant v4 UUID.
unitTestTearDown()
Cleanup resources when tearing down after a unit test (T46850)
string $uniqueFilePrefix
File prefix containing user ID to prevent collisions if multiple users run MediaWiki (T268420) and ge...
string $tmpDir
Temporary directory.
string $nodeId32
Node ID in binary (32 bits)
string $nodeId48
Node ID in binary (48 bits)
__construct( $tempDirectory, $shellCallback)
timeWaitUntil( $time)
Wait till the current timestamp reaches $time and return the current timestamp.
bool $loaded
Whether initialization completed.
newUUIDv1()
Return an RFC4122 compliant v1 UUID.
string $lockFile128
Local file path.
array $fileHandles
Cached file handles.
getTimestampFromUUIDv1(string $uuid, int $format=TS_MW)
Get timestamp in a specified format from UUIDv1.
callable $shellCallback
Callback for running shell commands.
getTimeAndDelay( $lockFile, $clockSeqSize, $counterSize, $offsetSize)
Get a (time,counter,clock sequence) where (time,counter) is higher than any previous (time,...
string $lockFileUUID
Local file path.
string $nodeIdFile
Local file path.
newSequentialPerNodeIDs( $bucket, $bits, $count, $flags=0)
Return IDs that are sequential only for this node and bucket.
intervalsSinceGregorianBinary(array $time, $delta=0)
string $lockFile88
Local file path.