1
|
|
|
<?php |
2
|
|
|
/** |
3
|
|
|
* Copyright © 2003-2004 Brion Vibber <[email protected]> |
4
|
|
|
* https://www.mediawiki.org/ |
5
|
|
|
* |
6
|
|
|
* This program is free software; you can redistribute it and/or modify |
7
|
|
|
* it under the terms of the GNU General Public License as published by |
8
|
|
|
* the Free Software Foundation; either version 2 of the License, or |
9
|
|
|
* (at your option) any later version. |
10
|
|
|
* |
11
|
|
|
* This program is distributed in the hope that it will be useful, |
12
|
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of |
13
|
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
14
|
|
|
* GNU General Public License for more details. |
15
|
|
|
* |
16
|
|
|
* You should have received a copy of the GNU General Public License along |
17
|
|
|
* with this program; if not, write to the Free Software Foundation, Inc., |
18
|
|
|
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. |
19
|
|
|
* http://www.gnu.org/copyleft/gpl.html |
20
|
|
|
* |
21
|
|
|
* @file |
22
|
|
|
* @ingroup Cache |
23
|
|
|
*/ |
24
|
|
|
|
25
|
|
|
/** |
26
|
|
|
* @defgroup Cache Cache |
27
|
|
|
*/ |
28
|
|
|
|
29
|
|
|
use Psr\Log\LoggerAwareInterface; |
30
|
|
|
use Psr\Log\LoggerInterface; |
31
|
|
|
use Psr\Log\NullLogger; |
32
|
|
|
use Wikimedia\ScopedCallback; |
|
|
|
|
33
|
|
|
use Wikimedia\WaitConditionLoop; |
34
|
|
|
|
35
|
|
|
/** |
36
|
|
|
* interface is intended to be more or less compatible with |
37
|
|
|
* the PHP memcached client. |
38
|
|
|
* |
39
|
|
|
* backends for local hash array and SQL table included: |
40
|
|
|
* @code |
41
|
|
|
* $bag = new HashBagOStuff(); |
42
|
|
|
* $bag = new SqlBagOStuff(); # connect to db first |
43
|
|
|
* @endcode |
44
|
|
|
* |
45
|
|
|
* @ingroup Cache |
46
|
|
|
*/ |
47
|
|
|
abstract class BagOStuff implements IExpiringStore, LoggerAwareInterface { |
48
|
|
|
/** @var array[] Lock tracking */ |
49
|
|
|
protected $locks = []; |
50
|
|
|
/** @var integer ERR_* class constant */ |
51
|
|
|
protected $lastError = self::ERR_NONE; |
52
|
|
|
/** @var string */ |
53
|
|
|
protected $keyspace = 'local'; |
54
|
|
|
/** @var LoggerInterface */ |
55
|
|
|
protected $logger; |
56
|
|
|
/** @var callback|null */ |
57
|
|
|
protected $asyncHandler; |
58
|
|
|
/** @var integer Seconds */ |
59
|
|
|
protected $syncTimeout; |
60
|
|
|
|
61
|
|
|
/** @var bool */ |
62
|
|
|
private $debugMode = false; |
63
|
|
|
/** @var array */ |
64
|
|
|
private $duplicateKeyLookups = []; |
65
|
|
|
/** @var bool */ |
66
|
|
|
private $reportDupes = false; |
67
|
|
|
/** @var bool */ |
68
|
|
|
private $dupeTrackScheduled = false; |
69
|
|
|
|
70
|
|
|
/** @var callable[] */ |
71
|
|
|
protected $busyCallbacks = []; |
72
|
|
|
|
73
|
|
|
/** @var integer[] Map of (ATTR_* class constant => QOS_* class constant) */ |
74
|
|
|
protected $attrMap = []; |
75
|
|
|
|
76
|
|
|
/** Possible values for getLastError() */ |
77
|
|
|
const ERR_NONE = 0; // no error |
78
|
|
|
const ERR_NO_RESPONSE = 1; // no response |
79
|
|
|
const ERR_UNREACHABLE = 2; // can't connect |
80
|
|
|
const ERR_UNEXPECTED = 3; // response gave some error |
81
|
|
|
|
82
|
|
|
/** Bitfield constants for get()/getMulti() */ |
83
|
|
|
const READ_LATEST = 1; // use latest data for replicated stores |
84
|
|
|
const READ_VERIFIED = 2; // promise that caller can tell when keys are stale |
85
|
|
|
/** Bitfield constants for set()/merge() */ |
86
|
|
|
const WRITE_SYNC = 1; // synchronously write to all locations for replicated stores |
87
|
|
|
const WRITE_CACHE_ONLY = 2; // Only change state of the in-memory cache |
88
|
|
|
|
89
|
|
|
/** |
90
|
|
|
* $params include: |
91
|
|
|
* - logger: Psr\Log\LoggerInterface instance |
92
|
|
|
* - keyspace: Default keyspace for $this->makeKey() |
93
|
|
|
* - asyncHandler: Callable to use for scheduling tasks after the web request ends. |
94
|
|
|
* In CLI mode, it should run the task immediately. |
95
|
|
|
* - reportDupes: Whether to emit warning log messages for all keys that were |
96
|
|
|
* requested more than once (requires an asyncHandler). |
97
|
|
|
* - syncTimeout: How long to wait with WRITE_SYNC in seconds. |
98
|
|
|
* @param array $params |
99
|
|
|
*/ |
100
|
|
|
public function __construct( array $params = [] ) { |
101
|
|
|
if ( isset( $params['logger'] ) ) { |
102
|
|
|
$this->setLogger( $params['logger'] ); |
103
|
|
|
} else { |
104
|
|
|
$this->setLogger( new NullLogger() ); |
105
|
|
|
} |
106
|
|
|
|
107
|
|
|
if ( isset( $params['keyspace'] ) ) { |
108
|
|
|
$this->keyspace = $params['keyspace']; |
109
|
|
|
} |
110
|
|
|
|
111
|
|
|
$this->asyncHandler = isset( $params['asyncHandler'] ) |
112
|
|
|
? $params['asyncHandler'] |
113
|
|
|
: null; |
114
|
|
|
|
115
|
|
|
if ( !empty( $params['reportDupes'] ) && is_callable( $this->asyncHandler ) ) { |
116
|
|
|
$this->reportDupes = true; |
117
|
|
|
} |
118
|
|
|
|
119
|
|
|
$this->syncTimeout = isset( $params['syncTimeout'] ) ? $params['syncTimeout'] : 3; |
120
|
|
|
} |
121
|
|
|
|
122
|
|
|
/** |
123
|
|
|
* @param LoggerInterface $logger |
124
|
|
|
* @return null |
125
|
|
|
*/ |
126
|
|
|
public function setLogger( LoggerInterface $logger ) { |
127
|
|
|
$this->logger = $logger; |
128
|
|
|
} |
129
|
|
|
|
130
|
|
|
/** |
131
|
|
|
* @param bool $bool |
132
|
|
|
*/ |
133
|
|
|
public function setDebug( $bool ) { |
134
|
|
|
$this->debugMode = $bool; |
135
|
|
|
} |
136
|
|
|
|
137
|
|
|
/** |
138
|
|
|
* Get an item with the given key, regenerating and setting it if not found |
139
|
|
|
* |
140
|
|
|
* If the callback returns false, then nothing is stored. |
141
|
|
|
* |
142
|
|
|
* @param string $key |
143
|
|
|
* @param int $ttl Time-to-live (seconds) |
144
|
|
|
* @param callable $callback Callback that derives the new value |
145
|
|
|
* @param integer $flags Bitfield of BagOStuff::READ_* constants [optional] |
146
|
|
|
* @return mixed The cached value if found or the result of $callback otherwise |
147
|
|
|
* @since 1.27 |
148
|
|
|
*/ |
149
|
|
|
final public function getWithSetCallback( $key, $ttl, $callback, $flags = 0 ) { |
150
|
|
|
$value = $this->get( $key, $flags ); |
151
|
|
|
|
152
|
|
|
if ( $value === false ) { |
153
|
|
|
if ( !is_callable( $callback ) ) { |
154
|
|
|
throw new InvalidArgumentException( "Invalid cache miss callback provided." ); |
155
|
|
|
} |
156
|
|
|
$value = call_user_func( $callback ); |
157
|
|
|
if ( $value !== false ) { |
158
|
|
|
$this->set( $key, $value, $ttl ); |
159
|
|
|
} |
160
|
|
|
} |
161
|
|
|
|
162
|
|
|
return $value; |
163
|
|
|
} |
164
|
|
|
|
165
|
|
|
/** |
166
|
|
|
* Get an item with the given key |
167
|
|
|
* |
168
|
|
|
* If the key includes a determistic input hash (e.g. the key can only have |
169
|
|
|
* the correct value) or complete staleness checks are handled by the caller |
170
|
|
|
* (e.g. nothing relies on the TTL), then the READ_VERIFIED flag should be set. |
171
|
|
|
* This lets tiered backends know they can safely upgrade a cached value to |
172
|
|
|
* higher tiers using standard TTLs. |
173
|
|
|
* |
174
|
|
|
* @param string $key |
175
|
|
|
* @param integer $flags Bitfield of BagOStuff::READ_* constants [optional] |
176
|
|
|
* @param integer $oldFlags [unused] |
177
|
|
|
* @return mixed Returns false on failure and if the item does not exist |
178
|
|
|
*/ |
179
|
|
|
public function get( $key, $flags = 0, $oldFlags = null ) { |
180
|
|
|
// B/C for ( $key, &$casToken = null, $flags = 0 ) |
181
|
|
|
$flags = is_int( $oldFlags ) ? $oldFlags : $flags; |
182
|
|
|
|
183
|
|
|
$this->trackDuplicateKeys( $key ); |
184
|
|
|
|
185
|
|
|
return $this->doGet( $key, $flags ); |
186
|
|
|
} |
187
|
|
|
|
188
|
|
|
/** |
189
|
|
|
* Track the number of times that a given key has been used. |
190
|
|
|
* @param string $key |
191
|
|
|
*/ |
192
|
|
|
private function trackDuplicateKeys( $key ) { |
193
|
|
|
if ( !$this->reportDupes ) { |
194
|
|
|
return; |
195
|
|
|
} |
196
|
|
|
|
197
|
|
|
if ( !isset( $this->duplicateKeyLookups[$key] ) ) { |
198
|
|
|
// Track that we have seen this key. This N-1 counting style allows |
199
|
|
|
// easy filtering with array_filter() later. |
200
|
|
|
$this->duplicateKeyLookups[$key] = 0; |
201
|
|
|
} else { |
202
|
|
|
$this->duplicateKeyLookups[$key] += 1; |
203
|
|
|
|
204
|
|
|
if ( $this->dupeTrackScheduled === false ) { |
205
|
|
|
$this->dupeTrackScheduled = true; |
206
|
|
|
// Schedule a callback that logs keys processed more than once by get(). |
207
|
|
|
call_user_func( $this->asyncHandler, function () { |
208
|
|
|
$dups = array_filter( $this->duplicateKeyLookups ); |
209
|
|
|
foreach ( $dups as $key => $count ) { |
210
|
|
|
$this->logger->warning( |
211
|
|
|
'Duplicate get(): "{key}" fetched {count} times', |
212
|
|
|
// Count is N-1 of the actual lookup count |
213
|
|
|
[ 'key' => $key, 'count' => $count + 1, ] |
214
|
|
|
); |
215
|
|
|
} |
216
|
|
|
} ); |
217
|
|
|
} |
218
|
|
|
} |
219
|
|
|
} |
220
|
|
|
|
221
|
|
|
/** |
222
|
|
|
* @param string $key |
223
|
|
|
* @param integer $flags Bitfield of BagOStuff::READ_* constants [optional] |
224
|
|
|
* @return mixed Returns false on failure and if the item does not exist |
225
|
|
|
*/ |
226
|
|
|
abstract protected function doGet( $key, $flags = 0 ); |
227
|
|
|
|
228
|
|
|
/** |
229
|
|
|
* @note: This method is only needed if merge() uses mergeViaCas() |
230
|
|
|
* |
231
|
|
|
* @param string $key |
232
|
|
|
* @param mixed $casToken |
233
|
|
|
* @param integer $flags Bitfield of BagOStuff::READ_* constants [optional] |
234
|
|
|
* @return mixed Returns false on failure and if the item does not exist |
235
|
|
|
* @throws Exception |
236
|
|
|
*/ |
237
|
|
|
protected function getWithToken( $key, &$casToken, $flags = 0 ) { |
238
|
|
|
throw new Exception( __METHOD__ . ' not implemented.' ); |
239
|
|
|
} |
240
|
|
|
|
241
|
|
|
/** |
242
|
|
|
* Set an item |
243
|
|
|
* |
244
|
|
|
* @param string $key |
245
|
|
|
* @param mixed $value |
246
|
|
|
* @param int $exptime Either an interval in seconds or a unix timestamp for expiry |
247
|
|
|
* @param int $flags Bitfield of BagOStuff::WRITE_* constants |
248
|
|
|
* @return bool Success |
249
|
|
|
*/ |
250
|
|
|
abstract public function set( $key, $value, $exptime = 0, $flags = 0 ); |
251
|
|
|
|
252
|
|
|
/** |
253
|
|
|
* Delete an item |
254
|
|
|
* |
255
|
|
|
* @param string $key |
256
|
|
|
* @return bool True if the item was deleted or not found, false on failure |
257
|
|
|
*/ |
258
|
|
|
abstract public function delete( $key ); |
259
|
|
|
|
260
|
|
|
/** |
261
|
|
|
* Merge changes into the existing cache value (possibly creating a new one) |
262
|
|
|
* |
263
|
|
|
* The callback function returns the new value given the current value |
264
|
|
|
* (which will be false if not present), and takes the arguments: |
265
|
|
|
* (this BagOStuff, cache key, current value, TTL). |
266
|
|
|
* The TTL parameter is reference set to $exptime. It can be overriden in the callback. |
267
|
|
|
* |
268
|
|
|
* @param string $key |
269
|
|
|
* @param callable $callback Callback method to be executed |
270
|
|
|
* @param int $exptime Either an interval in seconds or a unix timestamp for expiry |
271
|
|
|
* @param int $attempts The amount of times to attempt a merge in case of failure |
272
|
|
|
* @param int $flags Bitfield of BagOStuff::WRITE_* constants |
273
|
|
|
* @return bool Success |
274
|
|
|
* @throws InvalidArgumentException |
275
|
|
|
*/ |
276
|
|
|
public function merge( $key, callable $callback, $exptime = 0, $attempts = 10, $flags = 0 ) { |
277
|
|
|
return $this->mergeViaLock( $key, $callback, $exptime, $attempts, $flags ); |
278
|
|
|
} |
279
|
|
|
|
280
|
|
|
/** |
281
|
|
|
* @see BagOStuff::merge() |
282
|
|
|
* |
283
|
|
|
* @param string $key |
284
|
|
|
* @param callable $callback Callback method to be executed |
285
|
|
|
* @param int $exptime Either an interval in seconds or a unix timestamp for expiry |
286
|
|
|
* @param int $attempts The amount of times to attempt a merge in case of failure |
287
|
|
|
* @return bool Success |
288
|
|
|
*/ |
289
|
|
|
protected function mergeViaCas( $key, $callback, $exptime = 0, $attempts = 10 ) { |
290
|
|
|
do { |
291
|
|
|
$this->clearLastError(); |
292
|
|
|
$reportDupes = $this->reportDupes; |
293
|
|
|
$this->reportDupes = false; |
294
|
|
|
$casToken = null; // passed by reference |
295
|
|
|
$currentValue = $this->getWithToken( $key, $casToken, self::READ_LATEST ); |
296
|
|
|
$this->reportDupes = $reportDupes; |
297
|
|
|
|
298
|
|
|
if ( $this->getLastError() ) { |
299
|
|
|
return false; // don't spam retries (retry only on races) |
300
|
|
|
} |
301
|
|
|
|
302
|
|
|
// Derive the new value from the old value |
303
|
|
|
$value = call_user_func( $callback, $this, $key, $currentValue, $exptime ); |
304
|
|
|
|
305
|
|
|
$this->clearLastError(); |
306
|
|
View Code Duplication |
if ( $value === false ) { |
307
|
|
|
$success = true; // do nothing |
308
|
|
|
} elseif ( $currentValue === false ) { |
309
|
|
|
// Try to create the key, failing if it gets created in the meantime |
310
|
|
|
$success = $this->add( $key, $value, $exptime ); |
311
|
|
|
} else { |
312
|
|
|
// Try to update the key, failing if it gets changed in the meantime |
313
|
|
|
$success = $this->cas( $casToken, $key, $value, $exptime ); |
314
|
|
|
} |
315
|
|
|
if ( $this->getLastError() ) { |
316
|
|
|
return false; // IO error; don't spam retries |
317
|
|
|
} |
318
|
|
|
} while ( !$success && --$attempts ); |
319
|
|
|
|
320
|
|
|
return $success; |
321
|
|
|
} |
322
|
|
|
|
323
|
|
|
/** |
324
|
|
|
* Check and set an item |
325
|
|
|
* |
326
|
|
|
* @param mixed $casToken |
327
|
|
|
* @param string $key |
328
|
|
|
* @param mixed $value |
329
|
|
|
* @param int $exptime Either an interval in seconds or a unix timestamp for expiry |
330
|
|
|
* @return bool Success |
331
|
|
|
* @throws Exception |
332
|
|
|
*/ |
333
|
|
|
protected function cas( $casToken, $key, $value, $exptime = 0 ) { |
334
|
|
|
throw new Exception( "CAS is not implemented in " . __CLASS__ ); |
335
|
|
|
} |
336
|
|
|
|
337
|
|
|
/** |
338
|
|
|
* @see BagOStuff::merge() |
339
|
|
|
* |
340
|
|
|
* @param string $key |
341
|
|
|
* @param callable $callback Callback method to be executed |
342
|
|
|
* @param int $exptime Either an interval in seconds or a unix timestamp for expiry |
343
|
|
|
* @param int $attempts The amount of times to attempt a merge in case of failure |
344
|
|
|
* @param int $flags Bitfield of BagOStuff::WRITE_* constants |
345
|
|
|
* @return bool Success |
346
|
|
|
*/ |
347
|
|
|
protected function mergeViaLock( $key, $callback, $exptime = 0, $attempts = 10, $flags = 0 ) { |
348
|
|
|
if ( !$this->lock( $key, 6 ) ) { |
349
|
|
|
return false; |
350
|
|
|
} |
351
|
|
|
|
352
|
|
|
$this->clearLastError(); |
353
|
|
|
$reportDupes = $this->reportDupes; |
354
|
|
|
$this->reportDupes = false; |
355
|
|
|
$currentValue = $this->get( $key, self::READ_LATEST ); |
356
|
|
|
$this->reportDupes = $reportDupes; |
357
|
|
|
|
358
|
|
|
if ( $this->getLastError() ) { |
359
|
|
|
$success = false; |
360
|
|
View Code Duplication |
} else { |
361
|
|
|
// Derive the new value from the old value |
362
|
|
|
$value = call_user_func( $callback, $this, $key, $currentValue, $exptime ); |
363
|
|
|
if ( $value === false ) { |
364
|
|
|
$success = true; // do nothing |
365
|
|
|
} else { |
366
|
|
|
$success = $this->set( $key, $value, $exptime, $flags ); // set the new value |
367
|
|
|
} |
368
|
|
|
} |
369
|
|
|
|
370
|
|
|
if ( !$this->unlock( $key ) ) { |
371
|
|
|
// this should never happen |
372
|
|
|
trigger_error( "Could not release lock for key '$key'." ); |
373
|
|
|
} |
374
|
|
|
|
375
|
|
|
return $success; |
376
|
|
|
} |
377
|
|
|
|
378
|
|
|
/** |
379
|
|
|
* Reset the TTL on a key if it exists |
380
|
|
|
* |
381
|
|
|
* @param string $key |
382
|
|
|
* @param int $expiry |
383
|
|
|
* @return bool Success Returns false if there is no key |
384
|
|
|
* @since 1.28 |
385
|
|
|
*/ |
386
|
|
|
public function changeTTL( $key, $expiry = 0 ) { |
387
|
|
|
$value = $this->get( $key ); |
388
|
|
|
|
389
|
|
|
return ( $value === false ) ? false : $this->set( $key, $value, $expiry ); |
390
|
|
|
} |
391
|
|
|
|
392
|
|
|
/** |
393
|
|
|
* Acquire an advisory lock on a key string |
394
|
|
|
* |
395
|
|
|
* Note that if reentry is enabled, duplicate calls ignore $expiry |
396
|
|
|
* |
397
|
|
|
* @param string $key |
398
|
|
|
* @param int $timeout Lock wait timeout; 0 for non-blocking [optional] |
399
|
|
|
* @param int $expiry Lock expiry [optional]; 1 day maximum |
400
|
|
|
* @param string $rclass Allow reentry if set and the current lock used this value |
401
|
|
|
* @return bool Success |
402
|
|
|
*/ |
403
|
|
|
public function lock( $key, $timeout = 6, $expiry = 6, $rclass = '' ) { |
404
|
|
|
// Avoid deadlocks and allow lock reentry if specified |
405
|
|
|
if ( isset( $this->locks[$key] ) ) { |
406
|
|
|
if ( $rclass != '' && $this->locks[$key]['class'] === $rclass ) { |
407
|
|
|
++$this->locks[$key]['depth']; |
408
|
|
|
return true; |
409
|
|
|
} else { |
410
|
|
|
return false; |
411
|
|
|
} |
412
|
|
|
} |
413
|
|
|
|
414
|
|
|
$expiry = min( $expiry ?: INF, self::TTL_DAY ); |
415
|
|
|
$loop = new WaitConditionLoop( |
416
|
|
|
function () use ( $key, $timeout, $expiry ) { |
417
|
|
|
$this->clearLastError(); |
418
|
|
|
if ( $this->add( "{$key}:lock", 1, $expiry ) ) { |
419
|
|
|
return true; // locked! |
420
|
|
|
} elseif ( $this->getLastError() ) { |
421
|
|
|
return WaitConditionLoop::CONDITION_ABORTED; // network partition? |
422
|
|
|
} |
423
|
|
|
|
424
|
|
|
return WaitConditionLoop::CONDITION_CONTINUE; |
425
|
|
|
}, |
426
|
|
|
$timeout |
427
|
|
|
); |
428
|
|
|
|
429
|
|
|
$locked = ( $loop->invoke() === $loop::CONDITION_REACHED ); |
430
|
|
|
if ( $locked ) { |
431
|
|
|
$this->locks[$key] = [ 'class' => $rclass, 'depth' => 1 ]; |
432
|
|
|
} |
433
|
|
|
|
434
|
|
|
return $locked; |
435
|
|
|
} |
436
|
|
|
|
437
|
|
|
/** |
438
|
|
|
* Release an advisory lock on a key string |
439
|
|
|
* |
440
|
|
|
* @param string $key |
441
|
|
|
* @return bool Success |
442
|
|
|
*/ |
443
|
|
|
public function unlock( $key ) { |
444
|
|
|
if ( isset( $this->locks[$key] ) && --$this->locks[$key]['depth'] <= 0 ) { |
445
|
|
|
unset( $this->locks[$key] ); |
446
|
|
|
|
447
|
|
|
return $this->delete( "{$key}:lock" ); |
448
|
|
|
} |
449
|
|
|
|
450
|
|
|
return true; |
451
|
|
|
} |
452
|
|
|
|
453
|
|
|
/** |
454
|
|
|
* Get a lightweight exclusive self-unlocking lock |
455
|
|
|
* |
456
|
|
|
* Note that the same lock cannot be acquired twice. |
457
|
|
|
* |
458
|
|
|
* This is useful for task de-duplication or to avoid obtrusive |
459
|
|
|
* (though non-corrupting) DB errors like INSERT key conflicts |
460
|
|
|
* or deadlocks when using LOCK IN SHARE MODE. |
461
|
|
|
* |
462
|
|
|
* @param string $key |
463
|
|
|
* @param int $timeout Lock wait timeout; 0 for non-blocking [optional] |
464
|
|
|
* @param int $expiry Lock expiry [optional]; 1 day maximum |
465
|
|
|
* @param string $rclass Allow reentry if set and the current lock used this value |
466
|
|
|
* @return ScopedCallback|null Returns null on failure |
467
|
|
|
* @since 1.26 |
468
|
|
|
*/ |
469
|
|
|
final public function getScopedLock( $key, $timeout = 6, $expiry = 30, $rclass = '' ) { |
470
|
|
|
$expiry = min( $expiry ?: INF, self::TTL_DAY ); |
471
|
|
|
|
472
|
|
|
if ( !$this->lock( $key, $timeout, $expiry, $rclass ) ) { |
473
|
|
|
return null; |
474
|
|
|
} |
475
|
|
|
|
476
|
|
|
$lSince = microtime( true ); // lock timestamp |
477
|
|
|
|
478
|
|
|
return new ScopedCallback( function() use ( $key, $lSince, $expiry ) { |
479
|
|
|
$latency = .050; // latency skew (err towards keeping lock present) |
480
|
|
|
$age = ( microtime( true ) - $lSince + $latency ); |
481
|
|
|
if ( ( $age + $latency ) >= $expiry ) { |
482
|
|
|
$this->logger->warning( "Lock for $key held too long ($age sec)." ); |
483
|
|
|
return; // expired; it's not "safe" to delete the key |
484
|
|
|
} |
485
|
|
|
$this->unlock( $key ); |
486
|
|
|
} ); |
487
|
|
|
} |
488
|
|
|
|
489
|
|
|
/** |
490
|
|
|
* Delete all objects expiring before a certain date. |
491
|
|
|
* @param string $date The reference date in MW format |
492
|
|
|
* @param callable|bool $progressCallback Optional, a function which will be called |
493
|
|
|
* regularly during long-running operations with the percentage progress |
494
|
|
|
* as the first parameter. |
495
|
|
|
* |
496
|
|
|
* @return bool Success, false if unimplemented |
497
|
|
|
*/ |
498
|
|
|
public function deleteObjectsExpiringBefore( $date, $progressCallback = false ) { |
499
|
|
|
// stub |
500
|
|
|
return false; |
501
|
|
|
} |
502
|
|
|
|
503
|
|
|
/** |
504
|
|
|
* Get an associative array containing the item for each of the keys that have items. |
505
|
|
|
* @param array $keys List of strings |
506
|
|
|
* @param integer $flags Bitfield; supports READ_LATEST [optional] |
507
|
|
|
* @return array |
508
|
|
|
*/ |
509
|
|
|
public function getMulti( array $keys, $flags = 0 ) { |
510
|
|
|
$res = []; |
511
|
|
|
foreach ( $keys as $key ) { |
512
|
|
|
$val = $this->get( $key ); |
513
|
|
|
if ( $val !== false ) { |
514
|
|
|
$res[$key] = $val; |
515
|
|
|
} |
516
|
|
|
} |
517
|
|
|
return $res; |
518
|
|
|
} |
519
|
|
|
|
520
|
|
|
/** |
521
|
|
|
* Batch insertion |
522
|
|
|
* @param array $data $key => $value assoc array |
523
|
|
|
* @param int $exptime Either an interval in seconds or a unix timestamp for expiry |
524
|
|
|
* @return bool Success |
525
|
|
|
* @since 1.24 |
526
|
|
|
*/ |
527
|
|
|
public function setMulti( array $data, $exptime = 0 ) { |
528
|
|
|
$res = true; |
529
|
|
|
foreach ( $data as $key => $value ) { |
530
|
|
|
if ( !$this->set( $key, $value, $exptime ) ) { |
531
|
|
|
$res = false; |
532
|
|
|
} |
533
|
|
|
} |
534
|
|
|
return $res; |
535
|
|
|
} |
536
|
|
|
|
537
|
|
|
/** |
538
|
|
|
* @param string $key |
539
|
|
|
* @param mixed $value |
540
|
|
|
* @param int $exptime |
541
|
|
|
* @return bool Success |
542
|
|
|
*/ |
543
|
|
|
public function add( $key, $value, $exptime = 0 ) { |
544
|
|
|
if ( $this->get( $key ) === false ) { |
545
|
|
|
return $this->set( $key, $value, $exptime ); |
546
|
|
|
} |
547
|
|
|
return false; // key already set |
548
|
|
|
} |
549
|
|
|
|
550
|
|
|
/** |
551
|
|
|
* Increase stored value of $key by $value while preserving its TTL |
552
|
|
|
* @param string $key Key to increase |
553
|
|
|
* @param int $value Value to add to $key (Default 1) |
554
|
|
|
* @return int|bool New value or false on failure |
555
|
|
|
*/ |
556
|
|
|
public function incr( $key, $value = 1 ) { |
557
|
|
|
if ( !$this->lock( $key ) ) { |
558
|
|
|
return false; |
559
|
|
|
} |
560
|
|
|
$n = $this->get( $key ); |
561
|
|
|
if ( $this->isInteger( $n ) ) { // key exists? |
562
|
|
|
$n += intval( $value ); |
563
|
|
|
$this->set( $key, max( 0, $n ) ); // exptime? |
564
|
|
|
} else { |
565
|
|
|
$n = false; |
566
|
|
|
} |
567
|
|
|
$this->unlock( $key ); |
568
|
|
|
|
569
|
|
|
return $n; |
570
|
|
|
} |
571
|
|
|
|
572
|
|
|
/** |
573
|
|
|
* Decrease stored value of $key by $value while preserving its TTL |
574
|
|
|
* @param string $key |
575
|
|
|
* @param int $value |
576
|
|
|
* @return int|bool New value or false on failure |
577
|
|
|
*/ |
578
|
|
|
public function decr( $key, $value = 1 ) { |
579
|
|
|
return $this->incr( $key, - $value ); |
580
|
|
|
} |
581
|
|
|
|
582
|
|
|
/** |
583
|
|
|
* Increase stored value of $key by $value while preserving its TTL |
584
|
|
|
* |
585
|
|
|
* This will create the key with value $init and TTL $ttl instead if not present |
586
|
|
|
* |
587
|
|
|
* @param string $key |
588
|
|
|
* @param int $ttl |
589
|
|
|
* @param int $value |
590
|
|
|
* @param int $init |
591
|
|
|
* @return int|bool New value or false on failure |
592
|
|
|
* @since 1.24 |
593
|
|
|
*/ |
594
|
|
|
public function incrWithInit( $key, $ttl, $value = 1, $init = 1 ) { |
595
|
|
|
$newValue = $this->incr( $key, $value ); |
596
|
|
|
if ( $newValue === false ) { |
597
|
|
|
// No key set; initialize |
598
|
|
|
$newValue = $this->add( $key, (int)$init, $ttl ) ? $init : false; |
599
|
|
|
} |
600
|
|
|
if ( $newValue === false ) { |
601
|
|
|
// Raced out initializing; increment |
602
|
|
|
$newValue = $this->incr( $key, $value ); |
603
|
|
|
} |
604
|
|
|
|
605
|
|
|
return $newValue; |
606
|
|
|
} |
607
|
|
|
|
608
|
|
|
/** |
609
|
|
|
* Get the "last error" registered; clearLastError() should be called manually |
610
|
|
|
* @return int ERR_* constant for the "last error" registry |
611
|
|
|
* @since 1.23 |
612
|
|
|
*/ |
613
|
|
|
public function getLastError() { |
614
|
|
|
return $this->lastError; |
615
|
|
|
} |
616
|
|
|
|
617
|
|
|
/** |
618
|
|
|
* Clear the "last error" registry |
619
|
|
|
* @since 1.23 |
620
|
|
|
*/ |
621
|
|
|
public function clearLastError() { |
622
|
|
|
$this->lastError = self::ERR_NONE; |
623
|
|
|
} |
624
|
|
|
|
625
|
|
|
/** |
626
|
|
|
* Set the "last error" registry |
627
|
|
|
* @param int $err ERR_* constant |
628
|
|
|
* @since 1.23 |
629
|
|
|
*/ |
630
|
|
|
protected function setLastError( $err ) { |
631
|
|
|
$this->lastError = $err; |
632
|
|
|
} |
633
|
|
|
|
634
|
|
|
/** |
635
|
|
|
* Let a callback be run to avoid wasting time on special blocking calls |
636
|
|
|
* |
637
|
|
|
* The callbacks may or may not be called ever, in any particular order. |
638
|
|
|
* They are likely to be invoked when something WRITE_SYNC is used used. |
639
|
|
|
* They should follow a caching pattern as shown below, so that any code |
640
|
|
|
* using the word will get it's result no matter what happens. |
641
|
|
|
* @code |
642
|
|
|
* $result = null; |
643
|
|
|
* $workCallback = function () use ( &$result ) { |
644
|
|
|
* if ( !$result ) { |
645
|
|
|
* $result = .... |
646
|
|
|
* } |
647
|
|
|
* return $result; |
648
|
|
|
* } |
649
|
|
|
* @endcode |
650
|
|
|
* |
651
|
|
|
* @param callable $workCallback |
652
|
|
|
* @since 1.28 |
653
|
|
|
*/ |
654
|
|
|
public function addBusyCallback( callable $workCallback ) { |
655
|
|
|
$this->busyCallbacks[] = $workCallback; |
656
|
|
|
} |
657
|
|
|
|
658
|
|
|
/** |
659
|
|
|
* Modify a cache update operation array for EventRelayer::notify() |
660
|
|
|
* |
661
|
|
|
* This is used for relayed writes, e.g. for broadcasting a change |
662
|
|
|
* to multiple data-centers. If the array contains a 'val' field |
663
|
|
|
* then the command involves setting a key to that value. Note that |
664
|
|
|
* for simplicity, 'val' is always a simple scalar value. This method |
665
|
|
|
* is used to possibly serialize the value and add any cache-specific |
666
|
|
|
* key/values needed for the relayer daemon (e.g. memcached flags). |
667
|
|
|
* |
668
|
|
|
* @param array $event |
669
|
|
|
* @return array |
670
|
|
|
* @since 1.26 |
671
|
|
|
*/ |
672
|
|
|
public function modifySimpleRelayEvent( array $event ) { |
673
|
|
|
return $event; |
674
|
|
|
} |
675
|
|
|
|
676
|
|
|
/** |
677
|
|
|
* @param string $text |
678
|
|
|
*/ |
679
|
|
|
protected function debug( $text ) { |
680
|
|
|
if ( $this->debugMode ) { |
681
|
|
|
$this->logger->debug( "{class} debug: $text", [ |
682
|
|
|
'class' => get_class( $this ), |
683
|
|
|
] ); |
684
|
|
|
} |
685
|
|
|
} |
686
|
|
|
|
687
|
|
|
/** |
688
|
|
|
* Convert an optionally relative time to an absolute time |
689
|
|
|
* @param int $exptime |
690
|
|
|
* @return int |
691
|
|
|
*/ |
692
|
|
|
protected function convertExpiry( $exptime ) { |
693
|
|
|
if ( $exptime != 0 && $exptime < ( 10 * self::TTL_YEAR ) ) { |
694
|
|
|
return time() + $exptime; |
695
|
|
|
} else { |
696
|
|
|
return $exptime; |
697
|
|
|
} |
698
|
|
|
} |
699
|
|
|
|
700
|
|
|
/** |
701
|
|
|
* Convert an optionally absolute expiry time to a relative time. If an |
702
|
|
|
* absolute time is specified which is in the past, use a short expiry time. |
703
|
|
|
* |
704
|
|
|
* @param int $exptime |
705
|
|
|
* @return int |
706
|
|
|
*/ |
707
|
|
|
protected function convertToRelative( $exptime ) { |
708
|
|
|
if ( $exptime >= ( 10 * self::TTL_YEAR ) ) { |
709
|
|
|
$exptime -= time(); |
710
|
|
|
if ( $exptime <= 0 ) { |
711
|
|
|
$exptime = 1; |
712
|
|
|
} |
713
|
|
|
return $exptime; |
714
|
|
|
} else { |
715
|
|
|
return $exptime; |
716
|
|
|
} |
717
|
|
|
} |
718
|
|
|
|
719
|
|
|
/** |
720
|
|
|
* Check if a value is an integer |
721
|
|
|
* |
722
|
|
|
* @param mixed $value |
723
|
|
|
* @return bool |
724
|
|
|
*/ |
725
|
|
|
protected function isInteger( $value ) { |
726
|
|
|
return ( is_int( $value ) || ctype_digit( $value ) ); |
727
|
|
|
} |
728
|
|
|
|
729
|
|
|
/** |
730
|
|
|
* Construct a cache key. |
731
|
|
|
* |
732
|
|
|
* @since 1.27 |
733
|
|
|
* @param string $keyspace |
734
|
|
|
* @param array $args |
735
|
|
|
* @return string |
736
|
|
|
*/ |
737
|
|
|
public function makeKeyInternal( $keyspace, $args ) { |
738
|
|
|
$key = $keyspace; |
739
|
|
|
foreach ( $args as $arg ) { |
740
|
|
|
$arg = str_replace( ':', '%3A', $arg ); |
741
|
|
|
$key = $key . ':' . $arg; |
742
|
|
|
} |
743
|
|
|
return strtr( $key, ' ', '_' ); |
744
|
|
|
} |
745
|
|
|
|
746
|
|
|
/** |
747
|
|
|
* Make a global cache key. |
748
|
|
|
* |
749
|
|
|
* @since 1.27 |
750
|
|
|
* @param string ... Key component (variadic) |
751
|
|
|
* @return string |
752
|
|
|
*/ |
753
|
|
|
public function makeGlobalKey() { |
754
|
|
|
return $this->makeKeyInternal( 'global', func_get_args() ); |
755
|
|
|
} |
756
|
|
|
|
757
|
|
|
/** |
758
|
|
|
* Make a cache key, scoped to this instance's keyspace. |
759
|
|
|
* |
760
|
|
|
* @since 1.27 |
761
|
|
|
* @param string ... Key component (variadic) |
762
|
|
|
* @return string |
763
|
|
|
*/ |
764
|
|
|
public function makeKey() { |
765
|
|
|
return $this->makeKeyInternal( $this->keyspace, func_get_args() ); |
766
|
|
|
} |
767
|
|
|
|
768
|
|
|
/** |
769
|
|
|
* @param integer $flag ATTR_* class constant |
770
|
|
|
* @return integer QOS_* class constant |
771
|
|
|
* @since 1.28 |
772
|
|
|
*/ |
773
|
|
|
public function getQoS( $flag ) { |
774
|
|
|
return isset( $this->attrMap[$flag] ) ? $this->attrMap[$flag] : self::QOS_UNKNOWN; |
775
|
|
|
} |
776
|
|
|
|
777
|
|
|
/** |
778
|
|
|
* Merge the flag maps of one or more BagOStuff objects into a "lowest common denominator" map |
779
|
|
|
* |
780
|
|
|
* @param BagOStuff[] $bags |
781
|
|
|
* @return integer[] Resulting flag map (class ATTR_* constant => class QOS_* constant) |
782
|
|
|
*/ |
783
|
|
|
protected function mergeFlagMaps( array $bags ) { |
784
|
|
|
$map = []; |
785
|
|
|
foreach ( $bags as $bag ) { |
786
|
|
|
foreach ( $bag->attrMap as $attr => $rank ) { |
787
|
|
View Code Duplication |
if ( isset( $map[$attr] ) ) { |
788
|
|
|
$map[$attr] = min( $map[$attr], $rank ); |
789
|
|
|
} else { |
790
|
|
|
$map[$attr] = $rank; |
791
|
|
|
} |
792
|
|
|
} |
793
|
|
|
} |
794
|
|
|
|
795
|
|
|
return $map; |
796
|
|
|
} |
797
|
|
|
} |
798
|
|
|
|
Let’s assume that you have a directory layout like this:
and let’s assume the following content of
Bar.php
:If both files
OtherDir/Foo.php
andSomeDir/Foo.php
are loaded in the same runtime, you will see a PHP error such as the following:PHP Fatal error: Cannot use SomeDir\Foo as Foo because the name is already in use in OtherDir/Foo.php
However, as
OtherDir/Foo.php
does not necessarily have to be loaded and the error is only triggered if it is loaded beforeOtherDir/Bar.php
, this problem might go unnoticed for a while. In order to prevent this error from surfacing, you must import the namespace with a different alias: