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| 1 | <?php |
| 2 | /** |
| 3 | * @license GPL-2.0-or-later |
| 4 | * @file |
| 5 | */ |
| 6 | namespace Wikimedia\ObjectCache; |
| 7 | |
| 8 | use InvalidArgumentException; |
| 9 | use JsonSerializable; |
| 10 | use stdClass; |
| 11 | use Wikimedia\WaitConditionLoop; |
| 12 | |
| 13 | /** |
| 14 | * Helper classs that implements most of BagOStuff for a backend. |
| 15 | * |
| 16 | * This should be used by concrete implementations only. Wrapper classes that |
| 17 | * proxy another BagOStuff should extend and implement BagOStuff directly. |
| 18 | * |
| 19 | * @ingroup Cache |
| 20 | * @since 1.34 |
| 21 | */ |
| 22 | abstract class MediumSpecificBagOStuff extends BagOStuff { |
| 23 | /** @var array<string,array> Map of (key => (class LOCK_* constant => value) */ |
| 24 | protected $locks = []; |
| 25 | /** @var int Bytes; chunk size of segmented cache values */ |
| 26 | protected $segmentationSize; |
| 27 | /** @var int Bytes; maximum total size of a segmented cache value */ |
| 28 | protected $segmentedValueMaxSize; |
| 29 | |
| 30 | /** @var float Seconds; maximum expected seconds for a lock ping to reach the backend */ |
| 31 | protected $maxLockSendDelay = 0.05; |
| 32 | |
| 33 | /** @var array */ |
| 34 | private $duplicateKeyLookups = []; |
| 35 | /** @var bool */ |
| 36 | private $reportDupes = false; |
| 37 | /** @var bool */ |
| 38 | private $dupeTrackScheduled = false; |
| 39 | |
| 40 | /** Component to use for key construction of blob segment keys */ |
| 41 | private const SEGMENT_COMPONENT = 'segment'; |
| 42 | |
| 43 | /** Idiom for doGet() to return extra information by reference */ |
| 44 | protected const PASS_BY_REF = -1; |
| 45 | |
| 46 | protected const METRIC_OP_GET = 'get'; |
| 47 | protected const METRIC_OP_SET = 'set'; |
| 48 | protected const METRIC_OP_DELETE = 'delete'; |
| 49 | protected const METRIC_OP_CHANGE_TTL = 'change_ttl'; |
| 50 | protected const METRIC_OP_ADD = 'add'; |
| 51 | protected const METRIC_OP_INCR = 'incr'; |
| 52 | protected const METRIC_OP_DECR = 'decr'; |
| 53 | protected const METRIC_OP_CAS = 'cas'; |
| 54 | |
| 55 | protected const LOCK_RCLASS = 0; |
| 56 | protected const LOCK_DEPTH = 1; |
| 57 | protected const LOCK_TIME = 2; |
| 58 | protected const LOCK_EXPIRY = 3; |
| 59 | |
| 60 | /** |
| 61 | * @see BagOStuff::__construct() |
| 62 | * Additional $params options include: |
| 63 | * - logger: Psr\Log\LoggerInterface instance |
| 64 | * - reportDupes: Whether to emit warning log messages for all keys that were |
| 65 | * requested more than once (requires an asyncHandler). |
| 66 | * - segmentationSize: The chunk size, in bytes, of segmented values. The value should |
| 67 | * not exceed the maximum size of values in the storage backend, as configured by |
| 68 | * the site administrator. |
| 69 | * - segmentedValueMaxSize: The maximum total size, in bytes, of segmented values. |
| 70 | * This should be configured to a reasonable size give the site traffic and the |
| 71 | * amount of I/O between application and cache servers that the network can handle. |
| 72 | * |
| 73 | * @param array $params |
| 74 | * |
| 75 | * @phpcs:ignore Generic.Files.LineLength |
| 76 | * @phan-param array{logger?:\Psr\Log\LoggerInterface,asyncHandler?:callable,reportDupes?:bool,segmentationSize?:int|float,segmentedValueMaxSize?:int} $params |
| 77 | */ |
| 78 | public function __construct( array $params = [] ) { |
| 79 | parent::__construct( $params ); |
| 80 | |
| 81 | if ( !empty( $params['reportDupes'] ) && $this->asyncHandler ) { |
| 82 | $this->reportDupes = true; |
| 83 | } |
| 84 | |
| 85 | // Default to 8MiB if segmentationSize is not set |
| 86 | $this->segmentationSize = $params['segmentationSize'] ?? 8_388_608; |
| 87 | // Default to 64MiB if segmentedValueMaxSize is not set |
| 88 | $this->segmentedValueMaxSize = $params['segmentedValueMaxSize'] ?? 67_108_864; |
| 89 | } |
| 90 | |
| 91 | /** |
| 92 | * Get an item with the given key |
| 93 | * |
| 94 | * If the key includes a deterministic input hash (e.g. the key can only have |
| 95 | * the correct value) or complete staleness checks are handled by the caller |
| 96 | * (e.g. nothing relies on the TTL), then the READ_VERIFIED flag should be set. |
| 97 | * This lets tiered backends know they can safely upgrade a cached value to |
| 98 | * higher tiers using standard TTLs. |
| 99 | * |
| 100 | * @param string $key |
| 101 | * @param int $flags Bitfield of BagOStuff::READ_* constants [optional] |
| 102 | * |
| 103 | * @return mixed Returns false on failure or if the item does not exist |
| 104 | */ |
| 105 | public function get( $key, $flags = 0 ) { |
| 106 | $this->trackDuplicateKeys( $key ); |
| 107 | |
| 108 | return $this->resolveSegments( $key, $this->doGet( $key, $flags ) ); |
| 109 | } |
| 110 | |
| 111 | /** |
| 112 | * Track the number of times that a given key has been used. |
| 113 | * |
| 114 | * @param string $key |
| 115 | */ |
| 116 | private function trackDuplicateKeys( $key ) { |
| 117 | if ( !$this->reportDupes ) { |
| 118 | return; |
| 119 | } |
| 120 | |
| 121 | if ( !isset( $this->duplicateKeyLookups[$key] ) ) { |
| 122 | // Track that we have seen this key. This N-1 counting style allows |
| 123 | // easy filtering with array_filter() later. |
| 124 | $this->duplicateKeyLookups[$key] = 0; |
| 125 | } else { |
| 126 | $this->duplicateKeyLookups[$key]++; |
| 127 | |
| 128 | if ( $this->dupeTrackScheduled === false ) { |
| 129 | $this->dupeTrackScheduled = true; |
| 130 | // Schedule a callback that logs keys processed more than once by get(). |
| 131 | ( $this->asyncHandler )( function () { |
| 132 | $dups = array_filter( $this->duplicateKeyLookups ); |
| 133 | foreach ( $dups as $key => $count ) { |
| 134 | $this->logger->warning( |
| 135 | 'Duplicate get(): "{key}" fetched {count} times', |
| 136 | // Count is N-1 of the actual lookup count |
| 137 | [ 'key' => $key, 'count' => $count + 1, ] |
| 138 | ); |
| 139 | } |
| 140 | } ); |
| 141 | } |
| 142 | } |
| 143 | } |
| 144 | |
| 145 | /** |
| 146 | * Get an item |
| 147 | * |
| 148 | * The CAS token should be null if the key does not exist or the value is corrupt |
| 149 | * |
| 150 | * @param string $key |
| 151 | * @param int $flags Bitfield of BagOStuff::READ_* constants [optional] |
| 152 | * @param mixed &$casToken CAS token if MediumSpecificBagOStuff::PASS_BY_REF [returned] |
| 153 | * |
| 154 | * @return mixed Returns false on failure or if the item does not exist |
| 155 | */ |
| 156 | abstract protected function doGet( $key, $flags = 0, &$casToken = null ); |
| 157 | |
| 158 | /** @inheritDoc */ |
| 159 | public function set( $key, $value, $exptime = 0, $flags = 0 ) { |
| 160 | $entry = $this->makeValueOrSegmentList( $key, $value, $exptime, $flags, $ok ); |
| 161 | |
| 162 | // Only when all segments (if any) are stored should the main key be changed |
| 163 | return $ok && $this->doSet( $key, $entry, $exptime, $flags ); |
| 164 | } |
| 165 | |
| 166 | /** |
| 167 | * Set an item |
| 168 | * |
| 169 | * @param string $key |
| 170 | * @param mixed $value |
| 171 | * @param int $exptime Either an interval in seconds or a unix timestamp for expiry |
| 172 | * @param int $flags Bitfield of BagOStuff::WRITE_* constants |
| 173 | * |
| 174 | * @return bool Success |
| 175 | */ |
| 176 | abstract protected function doSet( $key, $value, $exptime = 0, $flags = 0 ); |
| 177 | |
| 178 | /** @inheritDoc */ |
| 179 | public function delete( $key, $flags = 0 ) { |
| 180 | if ( !$this->fieldHasFlags( $flags, self::WRITE_ALLOW_SEGMENTS ) ) { |
| 181 | return $this->doDelete( $key, $flags ); |
| 182 | } |
| 183 | |
| 184 | $mainValue = $this->doGet( $key, self::READ_LATEST ); |
| 185 | if ( !$this->doDelete( $key, $flags ) ) { |
| 186 | return false; |
| 187 | } |
| 188 | |
| 189 | if ( !SerializedValueContainer::isSegmented( $mainValue ) ) { |
| 190 | // no segments to delete |
| 191 | return true; |
| 192 | } |
| 193 | |
| 194 | $orderedKeys = array_map( |
| 195 | function ( $segmentHash ) use ( $key ) { |
| 196 | return $this->makeGlobalKey( self::SEGMENT_COMPONENT, $key, $segmentHash ); |
| 197 | }, |
| 198 | $mainValue->{SerializedValueContainer::SEGMENTED_HASHES} |
| 199 | ); |
| 200 | |
| 201 | return $this->deleteMulti( $orderedKeys, $flags & ~self::WRITE_ALLOW_SEGMENTS ); |
| 202 | } |
| 203 | |
| 204 | /** |
| 205 | * Delete an item |
| 206 | * |
| 207 | * @param string $key |
| 208 | * @param int $flags Bitfield of BagOStuff::WRITE_* constants |
| 209 | * |
| 210 | * @return bool True if the item was deleted or not found, false on failure |
| 211 | */ |
| 212 | abstract protected function doDelete( $key, $flags = 0 ); |
| 213 | |
| 214 | /** @inheritDoc */ |
| 215 | public function add( $key, $value, $exptime = 0, $flags = 0 ) { |
| 216 | $entry = $this->makeValueOrSegmentList( $key, $value, $exptime, $flags, $ok ); |
| 217 | |
| 218 | // Only when all segments (if any) are stored should the main key be changed |
| 219 | return $ok && $this->doAdd( $key, $entry, $exptime, $flags ); |
| 220 | } |
| 221 | |
| 222 | /** |
| 223 | * Insert an item if it does not already exist |
| 224 | * |
| 225 | * @param string $key |
| 226 | * @param mixed $value |
| 227 | * @param int $exptime |
| 228 | * @param int $flags Bitfield of BagOStuff::WRITE_* constants (since 1.33) |
| 229 | * |
| 230 | * @return bool Success |
| 231 | */ |
| 232 | abstract protected function doAdd( $key, $value, $exptime = 0, $flags = 0 ); |
| 233 | |
| 234 | /** |
| 235 | * Merge changes into the existing cache value (possibly creating a new one) |
| 236 | * |
| 237 | * The callback function returns the new value given the current value |
| 238 | * (which will be false if not present), and takes the arguments: |
| 239 | * (this BagOStuff, cache key, current value, TTL). |
| 240 | * The TTL parameter is reference set to $exptime. It can be overridden in the callback. |
| 241 | * Nothing is stored nor deleted if the callback returns false. |
| 242 | * |
| 243 | * @param string $key |
| 244 | * @param callable $callback Callback method to be executed |
| 245 | * @param int $exptime Either an interval in seconds or a unix timestamp for expiry |
| 246 | * @param int $attempts The amount of times to attempt a merge in case of failure |
| 247 | * @param int $flags Bitfield of BagOStuff::WRITE_* constants |
| 248 | * |
| 249 | * @return bool Success |
| 250 | */ |
| 251 | public function merge( $key, callable $callback, $exptime = 0, $attempts = 10, $flags = 0 ) { |
| 252 | return $this->mergeViaCas( $key, $callback, $exptime, $attempts, $flags ); |
| 253 | } |
| 254 | |
| 255 | /** |
| 256 | * @param string $key |
| 257 | * @param callable $callback Callback method to be executed |
| 258 | * @param int $exptime Either an interval in seconds or a unix timestamp for expiry |
| 259 | * @param int $attempts The amount of times to attempt a merge in case of failure |
| 260 | * @param int $flags Bitfield of BagOStuff::WRITE_* constants |
| 261 | * |
| 262 | * @return bool Success |
| 263 | * @see BagOStuff::merge() |
| 264 | */ |
| 265 | final protected function mergeViaCas( $key, callable $callback, $exptime, $attempts, $flags ) { |
| 266 | $attemptsLeft = $attempts; |
| 267 | do { |
| 268 | $token = self::PASS_BY_REF; |
| 269 | // Get the old value and CAS token from cache |
| 270 | $watchPoint = $this->watchErrors(); |
| 271 | $currentValue = $this->resolveSegments( |
| 272 | $key, |
| 273 | $this->doGet( $key, $flags, $token ) |
| 274 | ); |
| 275 | if ( $this->getLastError( $watchPoint ) ) { |
| 276 | // Don't spam slow retries due to network problems (retry only on races) |
| 277 | $this->logger->warning( |
| 278 | __METHOD__ . ' failed due to read I/O error on get() for {key}.', [ 'key' => $key ] |
| 279 | ); |
| 280 | $success = false; |
| 281 | break; |
| 282 | } |
| 283 | |
| 284 | // Derive the new value from the old value |
| 285 | $value = $callback( $this, $key, $currentValue, $exptime ); |
| 286 | $keyWasNonexistent = ( $currentValue === false ); |
| 287 | $valueMatchesOldValue = ( $value === $currentValue ); |
| 288 | // free RAM in case the value is large |
| 289 | unset( $currentValue ); |
| 290 | |
| 291 | $watchPoint = $this->watchErrors(); |
| 292 | if ( $value === false || $exptime < 0 ) { |
| 293 | // do nothing |
| 294 | $success = true; |
| 295 | } elseif ( $valueMatchesOldValue && $attemptsLeft !== $attempts ) { |
| 296 | // recently set by another thread to the same value |
| 297 | $success = true; |
| 298 | } elseif ( $keyWasNonexistent ) { |
| 299 | // Try to create the key, failing if it gets created in the meantime |
| 300 | $success = $this->add( $key, $value, $exptime, $flags ); |
| 301 | } else { |
| 302 | // Try to update the key, failing if it gets changed in the meantime |
| 303 | $success = $this->cas( $token, $key, $value, $exptime, $flags ); |
| 304 | } |
| 305 | if ( $this->getLastError( $watchPoint ) ) { |
| 306 | // Don't spam slow retries due to network problems (retry only on races) |
| 307 | $this->logger->warning( |
| 308 | __METHOD__ . ' failed due to write I/O error for {key}.', |
| 309 | [ 'key' => $key ] |
| 310 | ); |
| 311 | $success = false; |
| 312 | break; |
| 313 | } |
| 314 | |
| 315 | } while ( !$success && --$attemptsLeft ); |
| 316 | |
| 317 | return $success; |
| 318 | } |
| 319 | |
| 320 | /** |
| 321 | * Set an item if the current CAS token matches the provided CAS token |
| 322 | * |
| 323 | * @param mixed $casToken Only set the item if it still has this CAS token |
| 324 | * @param string $key |
| 325 | * @param mixed $value |
| 326 | * @param int $exptime Either an interval in seconds or a unix timestamp for expiry |
| 327 | * @param int $flags Bitfield of BagOStuff::WRITE_* constants |
| 328 | * |
| 329 | * @return bool Success |
| 330 | */ |
| 331 | protected function cas( $casToken, $key, $value, $exptime = 0, $flags = 0 ) { |
| 332 | if ( $casToken === null ) { |
| 333 | $this->logger->warning( |
| 334 | __METHOD__ . ' got empty CAS token for {key}.', |
| 335 | [ 'key' => $key ] |
| 336 | ); |
| 337 | |
| 338 | // caller may have meant to use add()? |
| 339 | return false; |
| 340 | } |
| 341 | |
| 342 | $entry = $this->makeValueOrSegmentList( $key, $value, $exptime, $flags, $ok ); |
| 343 | |
| 344 | // Only when all segments (if any) are stored should the main key be changed |
| 345 | return $ok && $this->doCas( $casToken, $key, $entry, $exptime, $flags ); |
| 346 | } |
| 347 | |
| 348 | /** |
| 349 | * Set an item if the current CAS token matches the provided CAS token |
| 350 | * |
| 351 | * @param mixed $casToken CAS token from an existing version of the key |
| 352 | * @param string $key |
| 353 | * @param mixed $value |
| 354 | * @param int $exptime Either an interval in seconds or a unix timestamp for expiry |
| 355 | * @param int $flags Bitfield of BagOStuff::WRITE_* constants |
| 356 | * |
| 357 | * @return bool Success |
| 358 | */ |
| 359 | protected function doCas( $casToken, $key, $value, $exptime = 0, $flags = 0 ) { |
| 360 | // @TODO: the use of lock() assumes that all other relevant sets() use a lock |
| 361 | if ( !$this->lock( $key, 0 ) ) { |
| 362 | // non-blocking |
| 363 | return false; |
| 364 | } |
| 365 | |
| 366 | $curCasToken = self::PASS_BY_REF; |
| 367 | $watchPoint = $this->watchErrors(); |
| 368 | $exists = ( $this->doGet( $key, self::READ_LATEST, $curCasToken ) !== false ); |
| 369 | if ( $this->getLastError( $watchPoint ) ) { |
| 370 | // Fail if the old CAS token could not be read |
| 371 | $success = false; |
| 372 | $this->logger->warning( |
| 373 | __METHOD__ . ' failed due to write I/O error for {key}.', |
| 374 | [ 'key' => $key ] |
| 375 | ); |
| 376 | } elseif ( $exists && $this->tokensMatch( $casToken, $curCasToken ) ) { |
| 377 | $success = $this->doSet( $key, $value, $exptime, $flags ); |
| 378 | } else { |
| 379 | // mismatched or failed |
| 380 | $success = false; |
| 381 | $this->logger->info( |
| 382 | __METHOD__ . ' failed due to race condition for {key}.', |
| 383 | [ 'key' => $key, 'key_exists' => $exists ] |
| 384 | ); |
| 385 | } |
| 386 | |
| 387 | $this->unlock( $key ); |
| 388 | |
| 389 | return $success; |
| 390 | } |
| 391 | |
| 392 | /** |
| 393 | * @param mixed $value CAS token for an existing key |
| 394 | * @param mixed $otherValue CAS token for an existing key |
| 395 | * |
| 396 | * @return bool Whether the two tokens match |
| 397 | */ |
| 398 | final protected function tokensMatch( $value, $otherValue ) { |
| 399 | $type = gettype( $value ); |
| 400 | // Ideally, tokens are counters, timestamps, hashes, or serialized PHP values. |
| 401 | // However, some classes might use the PHP values themselves. |
| 402 | if ( $type !== gettype( $otherValue ) ) { |
| 403 | return false; |
| 404 | } |
| 405 | // Serialize both tokens to strictly compare objects or arrays (which might objects |
| 406 | // nested inside). Note that this will not apply if integer/string CAS tokens are used. |
| 407 | if ( $type === 'array' || $type === 'object' ) { |
| 408 | return ( serialize( $value ) === serialize( $otherValue ) ); |
| 409 | } |
| 410 | |
| 411 | // For string/integer tokens, use a simple comparison |
| 412 | return ( $value === $otherValue ); |
| 413 | } |
| 414 | |
| 415 | /** |
| 416 | * Change the expiration on a key if it exists |
| 417 | * |
| 418 | * If an expiry in the past is given then the key will immediately be expired |
| 419 | * |
| 420 | * For large values written using WRITE_ALLOW_SEGMENTS, this only changes the TTL of the |
| 421 | * main segment list key. While lowering the TTL of the segment list key has the effect of |
| 422 | * functionally lowering the TTL of the key, it might leave unused blobs in cache for longer. |
| 423 | * Raising the TTL of such keys is not effective, since the expiration of a single segment |
| 424 | * key effectively expires the entire value. |
| 425 | * |
| 426 | * @param string $key |
| 427 | * @param int $exptime TTL or UNIX timestamp |
| 428 | * @param int $flags Bitfield of BagOStuff::WRITE_* constants (since 1.33) |
| 429 | * |
| 430 | * @return bool Success Returns false on failure or if the item does not exist |
| 431 | * @since 1.28 |
| 432 | */ |
| 433 | public function changeTTL( $key, $exptime = 0, $flags = 0 ) { |
| 434 | return $this->doChangeTTL( $key, $exptime, $flags ); |
| 435 | } |
| 436 | |
| 437 | /** |
| 438 | * @param string $key |
| 439 | * @param int $exptime |
| 440 | * @param int $flags |
| 441 | * |
| 442 | * @return bool |
| 443 | */ |
| 444 | protected function doChangeTTL( $key, $exptime, $flags ) { |
| 445 | // @TODO: the use of lock() assumes that all other relevant sets() use a lock |
| 446 | if ( !$this->lock( $key, 0 ) ) { |
| 447 | return false; |
| 448 | } |
| 449 | |
| 450 | $expiry = $this->getExpirationAsTimestamp( $exptime ); |
| 451 | $delete = ( $expiry != self::TTL_INDEFINITE && $expiry < $this->getCurrentTime() ); |
| 452 | |
| 453 | // Use doGet() to avoid having to trigger resolveSegments() |
| 454 | $blob = $this->doGet( $key, self::READ_LATEST ); |
| 455 | if ( $blob ) { |
| 456 | if ( $delete ) { |
| 457 | $ok = $this->doDelete( $key, $flags ); |
| 458 | } else { |
| 459 | $ok = $this->doSet( $key, $blob, $exptime, $flags ); |
| 460 | } |
| 461 | } else { |
| 462 | $ok = false; |
| 463 | } |
| 464 | |
| 465 | $this->unlock( $key ); |
| 466 | |
| 467 | return $ok; |
| 468 | } |
| 469 | |
| 470 | /** @inheritDoc */ |
| 471 | public function incrWithInit( $key, $exptime, $step = 1, $init = null, $flags = 0 ) { |
| 472 | $step = (int)$step; |
| 473 | $init = is_int( $init ) ? $init : $step; |
| 474 | |
| 475 | return $this->doIncrWithInit( $key, $exptime, $step, $init, $flags ); |
| 476 | } |
| 477 | |
| 478 | /** |
| 479 | * @param string $key |
| 480 | * @param int $exptime |
| 481 | * @param int $step |
| 482 | * @param int $init |
| 483 | * @param int $flags |
| 484 | * |
| 485 | * @return int|bool New value or false on failure |
| 486 | */ |
| 487 | abstract protected function doIncrWithInit( $key, $exptime, $step, $init, $flags ); |
| 488 | |
| 489 | /** |
| 490 | * @param string $key |
| 491 | * @param int $timeout |
| 492 | * @param int $exptime |
| 493 | * @param string $rclass |
| 494 | * |
| 495 | * @return bool |
| 496 | */ |
| 497 | public function lock( $key, $timeout = 6, $exptime = 6, $rclass = '' ) { |
| 498 | $exptime = min( $exptime ?: INF, self::TTL_DAY ); |
| 499 | |
| 500 | $acquired = false; |
| 501 | |
| 502 | if ( isset( $this->locks[$key] ) ) { |
| 503 | // Already locked; avoid deadlocks and allow lock reentry if specified |
| 504 | if ( $rclass != '' && $this->locks[$key][self::LOCK_RCLASS] === $rclass ) { |
| 505 | ++$this->locks[$key][self::LOCK_DEPTH]; |
| 506 | $acquired = true; |
| 507 | } |
| 508 | } else { |
| 509 | // Not already locked; acquire a lock on the backend |
| 510 | $lockTsUnix = $this->doLock( $key, $timeout, $exptime ); |
| 511 | if ( $lockTsUnix !== null ) { |
| 512 | $this->locks[$key] = [ |
| 513 | self::LOCK_RCLASS => $rclass, |
| 514 | self::LOCK_DEPTH => 1, |
| 515 | self::LOCK_TIME => $lockTsUnix, |
| 516 | self::LOCK_EXPIRY => $lockTsUnix + $exptime |
| 517 | ]; |
| 518 | $acquired = true; |
| 519 | } |
| 520 | } |
| 521 | |
| 522 | return $acquired; |
| 523 | } |
| 524 | |
| 525 | /** |
| 526 | * @see MediumSpecificBagOStuff::lock() |
| 527 | * |
| 528 | * @param string $key |
| 529 | * @param int $timeout Lock wait timeout; 0 for non-blocking [optional] |
| 530 | * @param int $exptime Lock time-to-live 1 day maximum [optional] |
| 531 | * |
| 532 | * @return float|null UNIX timestamp of acquisition; null on failure |
| 533 | */ |
| 534 | protected function doLock( $key, $timeout, $exptime ) { |
| 535 | $lockTsUnix = null; |
| 536 | |
| 537 | $fname = __METHOD__; |
| 538 | $loop = new WaitConditionLoop( |
| 539 | function () use ( $key, $exptime, $fname, &$lockTsUnix ) { |
| 540 | $watchPoint = $this->watchErrors(); |
| 541 | if ( $this->add( $this->makeLockKey( $key ), 1, $exptime ) ) { |
| 542 | $lockTsUnix = microtime( true ); |
| 543 | |
| 544 | return WaitConditionLoop::CONDITION_REACHED; |
| 545 | } elseif ( $this->getLastError( $watchPoint ) ) { |
| 546 | $this->logger->warning( |
| 547 | "$fname failed due to I/O error for {key}.", |
| 548 | [ 'key' => $key ] |
| 549 | ); |
| 550 | |
| 551 | return WaitConditionLoop::CONDITION_ABORTED; |
| 552 | } |
| 553 | |
| 554 | return WaitConditionLoop::CONDITION_CONTINUE; |
| 555 | }, |
| 556 | $timeout |
| 557 | ); |
| 558 | $code = $loop->invoke(); |
| 559 | |
| 560 | if ( $code === $loop::CONDITION_TIMED_OUT ) { |
| 561 | $this->logger->warning( |
| 562 | "$fname failed due to timeout for {key}.", |
| 563 | [ 'key' => $key, 'timeout' => $timeout ] |
| 564 | ); |
| 565 | } |
| 566 | |
| 567 | return $lockTsUnix; |
| 568 | } |
| 569 | |
| 570 | /** |
| 571 | * Release an advisory lock on a key string |
| 572 | * |
| 573 | * @param string $key |
| 574 | * |
| 575 | * @return bool Success |
| 576 | */ |
| 577 | public function unlock( $key ) { |
| 578 | $released = false; |
| 579 | |
| 580 | if ( isset( $this->locks[$key] ) ) { |
| 581 | if ( --$this->locks[$key][self::LOCK_DEPTH] > 0 ) { |
| 582 | $released = true; |
| 583 | } else { |
| 584 | $released = $this->doUnlock( $key ); |
| 585 | unset( $this->locks[$key] ); |
| 586 | if ( !$released ) { |
| 587 | $this->logger->warning( |
| 588 | __METHOD__ . ' failed to release lock for {key}.', |
| 589 | [ 'key' => $key ] |
| 590 | ); |
| 591 | } |
| 592 | } |
| 593 | } else { |
| 594 | $this->logger->warning( |
| 595 | __METHOD__ . ' no lock to release for {key}.', |
| 596 | [ 'key' => $key ] |
| 597 | ); |
| 598 | } |
| 599 | |
| 600 | return $released; |
| 601 | } |
| 602 | |
| 603 | /** |
| 604 | * @see MediumSpecificBagOStuff::unlock() |
| 605 | * |
| 606 | * @param string $key |
| 607 | * |
| 608 | * @return bool Success |
| 609 | */ |
| 610 | protected function doUnlock( $key ) { |
| 611 | $released = false; |
| 612 | |
| 613 | // Estimate the remaining TTL of the lock key |
| 614 | $curTTL = $this->locks[$key][self::LOCK_EXPIRY] - $this->getCurrentTime(); |
| 615 | |
| 616 | // Check the risk of race conditions for key deletion |
| 617 | if ( $this->getQoS( self::ATTR_DURABILITY ) <= self::QOS_DURABILITY_SCRIPT ) { |
| 618 | // Lock (and data) keys use memory specific to this request (e.g. HashBagOStuff) |
| 619 | $isSafe = true; |
| 620 | } else { |
| 621 | // It is unsafe to delete the lock key if there is a serious risk of the key already |
| 622 | // being claimed by another thread before the delete operation reaches the backend |
| 623 | $isSafe = ( $curTTL > $this->maxLockSendDelay ); |
| 624 | } |
| 625 | |
| 626 | if ( $isSafe ) { |
| 627 | $released = $this->doDelete( $this->makeLockKey( $key ) ); |
| 628 | } else { |
| 629 | $this->logger->warning( |
| 630 | "Lock for {key} held too long ({age} sec).", |
| 631 | [ 'key' => $key, 'curTTL' => $curTTL ] |
| 632 | ); |
| 633 | } |
| 634 | |
| 635 | return $released; |
| 636 | } |
| 637 | |
| 638 | /** |
| 639 | * @param string $key |
| 640 | * |
| 641 | * @return string |
| 642 | */ |
| 643 | protected function makeLockKey( $key ) { |
| 644 | return "$key:lock"; |
| 645 | } |
| 646 | |
| 647 | /** @inheritDoc */ |
| 648 | public function deleteObjectsExpiringBefore( |
| 649 | $timestamp, |
| 650 | ?callable $progress = null, |
| 651 | $limit = INF, |
| 652 | ?string $tag = null |
| 653 | ) { |
| 654 | return false; |
| 655 | } |
| 656 | |
| 657 | /** |
| 658 | * Get an associative array containing the item for each of the keys that have items. |
| 659 | * |
| 660 | * @param string[] $keys List of keys; can be a map of (unused => key) for convenience |
| 661 | * @param int $flags Bitfield; supports READ_LATEST [optional] |
| 662 | * |
| 663 | * @return mixed[] Map of (key => value) for existing keys; preserves the order of $keys |
| 664 | */ |
| 665 | public function getMulti( array $keys, $flags = 0 ) { |
| 666 | $foundByKey = $this->doGetMulti( $keys, $flags ); |
| 667 | |
| 668 | $res = []; |
| 669 | foreach ( $keys as $key ) { |
| 670 | // Resolve one blob at a time (avoids too much I/O at once) |
| 671 | if ( array_key_exists( $key, $foundByKey ) ) { |
| 672 | // A value should not appear in the key if a segment is missing |
| 673 | $value = $this->resolveSegments( $key, $foundByKey[$key] ); |
| 674 | if ( $value !== false ) { |
| 675 | $res[$key] = $value; |
| 676 | } |
| 677 | } |
| 678 | } |
| 679 | |
| 680 | return $res; |
| 681 | } |
| 682 | |
| 683 | /** |
| 684 | * Get an associative array containing the item for each of the keys that have items. |
| 685 | * |
| 686 | * @param string[] $keys List of keys |
| 687 | * @param int $flags Bitfield; supports READ_LATEST [optional] |
| 688 | * |
| 689 | * @return array Map of (key => value) for existing keys; preserves the order of $keys |
| 690 | */ |
| 691 | protected function doGetMulti( array $keys, $flags = 0 ) { |
| 692 | $res = []; |
| 693 | foreach ( $keys as $key ) { |
| 694 | $val = $this->doGet( $key, $flags ); |
| 695 | if ( $val !== false ) { |
| 696 | $res[$key] = $val; |
| 697 | } |
| 698 | } |
| 699 | |
| 700 | return $res; |
| 701 | } |
| 702 | |
| 703 | /** |
| 704 | * Batch insertion/replace |
| 705 | * |
| 706 | * This does not support WRITE_ALLOW_SEGMENTS to avoid excessive read I/O |
| 707 | * |
| 708 | * @param mixed[] $valueByKey Map of (key => value) |
| 709 | * @param int $exptime Either an interval in seconds or a unix timestamp for expiry |
| 710 | * @param int $flags Bitfield of BagOStuff::WRITE_* constants (since 1.33) |
| 711 | * |
| 712 | * @return bool Success |
| 713 | * @since 1.24 |
| 714 | */ |
| 715 | public function setMulti( array $valueByKey, $exptime = 0, $flags = 0 ) { |
| 716 | if ( $this->fieldHasFlags( $flags, self::WRITE_ALLOW_SEGMENTS ) ) { |
| 717 | throw new InvalidArgumentException( __METHOD__ . ' got WRITE_ALLOW_SEGMENTS' ); |
| 718 | } |
| 719 | |
| 720 | return $this->doSetMulti( $valueByKey, $exptime, $flags ); |
| 721 | } |
| 722 | |
| 723 | /** |
| 724 | * @param mixed[] $data Map of (key => value) |
| 725 | * @param int $exptime Either an interval in seconds or a unix timestamp for expiry |
| 726 | * @param int $flags Bitfield of BagOStuff::WRITE_* constants |
| 727 | * |
| 728 | * @return bool Success |
| 729 | */ |
| 730 | protected function doSetMulti( array $data, $exptime = 0, $flags = 0 ) { |
| 731 | $res = true; |
| 732 | foreach ( $data as $key => $value ) { |
| 733 | $res = $this->doSet( $key, $value, $exptime, $flags ) && $res; |
| 734 | } |
| 735 | |
| 736 | return $res; |
| 737 | } |
| 738 | |
| 739 | /** @inheritDoc */ |
| 740 | public function deleteMulti( array $keys, $flags = 0 ) { |
| 741 | if ( $this->fieldHasFlags( $flags, self::WRITE_ALLOW_SEGMENTS ) ) { |
| 742 | throw new InvalidArgumentException( __METHOD__ . ' got WRITE_ALLOW_SEGMENTS' ); |
| 743 | } |
| 744 | |
| 745 | return $this->doDeleteMulti( $keys, $flags ); |
| 746 | } |
| 747 | |
| 748 | /** |
| 749 | * @param string[] $keys List of keys |
| 750 | * @param int $flags Bitfield of BagOStuff::WRITE_* constants |
| 751 | * |
| 752 | * @return bool Success |
| 753 | */ |
| 754 | protected function doDeleteMulti( array $keys, $flags = 0 ) { |
| 755 | $res = true; |
| 756 | foreach ( $keys as $key ) { |
| 757 | $res = $this->doDelete( $key, $flags ) && $res; |
| 758 | } |
| 759 | |
| 760 | return $res; |
| 761 | } |
| 762 | |
| 763 | /** |
| 764 | * Change the expiration of multiple keys that exist |
| 765 | * |
| 766 | * @param string[] $keys List of keys |
| 767 | * @param int $exptime TTL or UNIX timestamp |
| 768 | * @param int $flags Bitfield of BagOStuff::WRITE_* constants (since 1.33) |
| 769 | * |
| 770 | * @return bool Success |
| 771 | * |
| 772 | * @since 1.34 |
| 773 | */ |
| 774 | public function changeTTLMulti( array $keys, $exptime, $flags = 0 ) { |
| 775 | return $this->doChangeTTLMulti( $keys, $exptime, $flags ); |
| 776 | } |
| 777 | |
| 778 | /** |
| 779 | * @param string[] $keys List of keys |
| 780 | * @param int $exptime TTL or UNIX timestamp |
| 781 | * @param int $flags Bitfield of BagOStuff::WRITE_* constants |
| 782 | * |
| 783 | * @return bool Success |
| 784 | */ |
| 785 | protected function doChangeTTLMulti( array $keys, $exptime, $flags = 0 ) { |
| 786 | $res = true; |
| 787 | foreach ( $keys as $key ) { |
| 788 | $res = $this->doChangeTTL( $key, $exptime, $flags ) && $res; |
| 789 | } |
| 790 | |
| 791 | return $res; |
| 792 | } |
| 793 | |
| 794 | /** |
| 795 | * Get and reassemble the chunks of blob at the given key |
| 796 | * |
| 797 | * @param string $key |
| 798 | * @param mixed $mainValue |
| 799 | * |
| 800 | * @return string|null|bool The combined string, false if missing, null on error |
| 801 | */ |
| 802 | final protected function resolveSegments( $key, $mainValue ) { |
| 803 | if ( SerializedValueContainer::isSegmented( $mainValue ) ) { |
| 804 | $orderedKeys = array_map( |
| 805 | function ( $segmentHash ) use ( $key ) { |
| 806 | return $this->makeGlobalKey( self::SEGMENT_COMPONENT, $key, $segmentHash ); |
| 807 | }, |
| 808 | $mainValue->{SerializedValueContainer::SEGMENTED_HASHES} |
| 809 | ); |
| 810 | |
| 811 | $segmentsByKey = $this->doGetMulti( $orderedKeys ); |
| 812 | |
| 813 | $parts = []; |
| 814 | foreach ( $orderedKeys as $segmentKey ) { |
| 815 | if ( isset( $segmentsByKey[$segmentKey] ) ) { |
| 816 | $parts[] = $segmentsByKey[$segmentKey]; |
| 817 | } else { |
| 818 | // missing segment |
| 819 | return false; |
| 820 | } |
| 821 | } |
| 822 | |
| 823 | return $this->unserialize( implode( '', $parts ) ); |
| 824 | } |
| 825 | |
| 826 | return $mainValue; |
| 827 | } |
| 828 | |
| 829 | /** |
| 830 | * Check if a value should use a segmentation wrapper due to its size |
| 831 | * |
| 832 | * In order to avoid extra serialization and/or twice-serialized wrappers, just check if |
| 833 | * the value is a large string. Support cache wrappers (e.g. WANObjectCache) that use 2D |
| 834 | * arrays to wrap values. This does not recurse in order to avoid overhead from complex |
| 835 | * structures and the risk of infinite loops (due to references). |
| 836 | * |
| 837 | * @param mixed $value |
| 838 | * @param int $flags |
| 839 | * |
| 840 | * @return bool |
| 841 | */ |
| 842 | private function useSegmentationWrapper( $value, $flags ) { |
| 843 | if ( |
| 844 | $this->segmentationSize === INF || |
| 845 | !$this->fieldHasFlags( $flags, self::WRITE_ALLOW_SEGMENTS ) |
| 846 | ) { |
| 847 | return false; |
| 848 | } |
| 849 | |
| 850 | if ( is_string( $value ) ) { |
| 851 | return ( strlen( $value ) >= $this->segmentationSize ); |
| 852 | } |
| 853 | |
| 854 | if ( is_array( $value ) ) { |
| 855 | // Expect that the contained value will be one of the first array entries |
| 856 | foreach ( array_slice( $value, 0, 4 ) as $v ) { |
| 857 | if ( is_string( $v ) && strlen( $v ) >= $this->segmentationSize ) { |
| 858 | return true; |
| 859 | } |
| 860 | } |
| 861 | } |
| 862 | |
| 863 | // Avoid breaking functions for incrementing/decrementing integer key values |
| 864 | return false; |
| 865 | } |
| 866 | |
| 867 | /** |
| 868 | * Make the entry to store at a key (inline or segment list), storing any segments |
| 869 | * |
| 870 | * @param string $key |
| 871 | * @param mixed $value |
| 872 | * @param int $exptime |
| 873 | * @param int $flags |
| 874 | * @param mixed|null &$ok Whether the entry is usable (e.g. no missing segments) [returned] |
| 875 | * |
| 876 | * @return mixed The entry (inline value, wrapped inline value, or wrapped segment list) |
| 877 | * @since 1.34 |
| 878 | */ |
| 879 | final protected function makeValueOrSegmentList( $key, $value, $exptime, $flags, &$ok ) { |
| 880 | $entry = $value; |
| 881 | $ok = true; |
| 882 | |
| 883 | if ( $this->useSegmentationWrapper( $value, $flags ) ) { |
| 884 | $segmentSize = $this->segmentationSize; |
| 885 | $maxTotalSize = $this->segmentedValueMaxSize; |
| 886 | $serialized = $this->getSerialized( $value, $key ); |
| 887 | $size = strlen( $serialized ); |
| 888 | if ( $size > $maxTotalSize ) { |
| 889 | $this->logger->warning( |
| 890 | "Value for {key} exceeds $maxTotalSize bytes; cannot segment.", |
| 891 | [ 'key' => $key ] |
| 892 | ); |
| 893 | } else { |
| 894 | // Split the serialized value into chunks and store them at different keys |
| 895 | $chunksByKey = []; |
| 896 | $segmentHashes = []; |
| 897 | $count = intdiv( $size, $segmentSize ) + ( ( $size % $segmentSize ) ? 1 : 0 ); |
| 898 | for ( $i = 0; $i < $count; ++$i ) { |
| 899 | $segment = substr( $serialized, $i * $segmentSize, $segmentSize ); |
| 900 | $hash = sha1( $segment ); |
| 901 | $chunkKey = $this->makeGlobalKey( self::SEGMENT_COMPONENT, $key, $hash ); |
| 902 | $chunksByKey[$chunkKey] = $segment; |
| 903 | $segmentHashes[] = $hash; |
| 904 | } |
| 905 | $flags &= ~self::WRITE_ALLOW_SEGMENTS; |
| 906 | $ok = $this->setMulti( $chunksByKey, $exptime, $flags ); |
| 907 | $entry = SerializedValueContainer::newSegmented( $segmentHashes ); |
| 908 | } |
| 909 | } |
| 910 | |
| 911 | return $entry; |
| 912 | } |
| 913 | |
| 914 | /** |
| 915 | * @param int|float $exptime |
| 916 | * |
| 917 | * @return bool Whether the expiry is non-infinite, and, negative or not a UNIX timestamp |
| 918 | * @since 1.34 |
| 919 | */ |
| 920 | final protected function isRelativeExpiration( $exptime ) { |
| 921 | return ( $exptime !== self::TTL_INDEFINITE && $exptime < ( 10 * self::TTL_YEAR ) ); |
| 922 | } |
| 923 | |
| 924 | /** |
| 925 | * Convert an optionally relative timestamp to an absolute time |
| 926 | * |
| 927 | * The input value will be cast to an integer and interpreted as follows: |
| 928 | * - zero: no expiry; return zero (e.g. TTL_INDEFINITE) |
| 929 | * - negative: relative TTL; return UNIX timestamp offset by this value |
| 930 | * - positive (< 10 years): relative TTL; return UNIX timestamp offset by this value |
| 931 | * - positive (>= 10 years): absolute UNIX timestamp; return this value |
| 932 | * |
| 933 | * @param int $exptime |
| 934 | * |
| 935 | * @return int Expiration timestamp or TTL_INDEFINITE for indefinite |
| 936 | * @since 1.34 |
| 937 | */ |
| 938 | final protected function getExpirationAsTimestamp( $exptime ) { |
| 939 | if ( $exptime == self::TTL_INDEFINITE ) { |
| 940 | return $exptime; |
| 941 | } |
| 942 | |
| 943 | return $this->isRelativeExpiration( $exptime ) |
| 944 | ? intval( $this->getCurrentTime() + $exptime ) |
| 945 | : $exptime; |
| 946 | } |
| 947 | |
| 948 | /** |
| 949 | * Convert an optionally absolute expiry time to a relative time. If an |
| 950 | * absolute time is specified which is in the past, use a short expiry time. |
| 951 | * |
| 952 | * The input value will be cast to an integer and interpreted as follows: |
| 953 | * - zero: no expiry; return zero (e.g. TTL_INDEFINITE) |
| 954 | * - negative: relative TTL; return a short expiry time (1 second) |
| 955 | * - positive (< 10 years): relative TTL; return this value |
| 956 | * - positive (>= 10 years): absolute UNIX timestamp; return offset to current time |
| 957 | * |
| 958 | * @param int $exptime |
| 959 | * |
| 960 | * @return int Relative TTL or TTL_INDEFINITE for indefinite |
| 961 | * @since 1.34 |
| 962 | */ |
| 963 | final protected function getExpirationAsTTL( $exptime ) { |
| 964 | if ( $exptime == self::TTL_INDEFINITE ) { |
| 965 | return $exptime; |
| 966 | } |
| 967 | |
| 968 | return $this->isRelativeExpiration( $exptime ) |
| 969 | ? $exptime |
| 970 | : (int)max( $exptime - $this->getCurrentTime(), 1 ); |
| 971 | } |
| 972 | |
| 973 | /** |
| 974 | * Check if a value is an integer |
| 975 | * |
| 976 | * @param mixed $value |
| 977 | * |
| 978 | * @return bool |
| 979 | */ |
| 980 | final protected function isInteger( $value ) { |
| 981 | if ( is_int( $value ) ) { |
| 982 | return true; |
| 983 | } elseif ( !is_string( $value ) ) { |
| 984 | return false; |
| 985 | } |
| 986 | |
| 987 | $integer = (int)$value; |
| 988 | |
| 989 | return ( $value === (string)$integer ); |
| 990 | } |
| 991 | |
| 992 | /** @inheritDoc */ |
| 993 | public function getQoS( $flag ) { |
| 994 | return $this->attrMap[$flag] ?? self::QOS_UNKNOWN; |
| 995 | } |
| 996 | |
| 997 | /** |
| 998 | * @deprecated since 1.43, not used anywhere. |
| 999 | */ |
| 1000 | public function getSegmentationSize() { |
| 1001 | wfDeprecated( __METHOD__, '1.43' ); |
| 1002 | |
| 1003 | return $this->segmentationSize; |
| 1004 | } |
| 1005 | |
| 1006 | /** |
| 1007 | * @deprecated since 1.43, not used anywhere. |
| 1008 | */ |
| 1009 | public function getSegmentedValueMaxSize() { |
| 1010 | wfDeprecated( __METHOD__, '1.43' ); |
| 1011 | |
| 1012 | return $this->segmentedValueMaxSize; |
| 1013 | } |
| 1014 | |
| 1015 | /** |
| 1016 | * Get the serialized form a value, logging a warning if it involves custom classes |
| 1017 | * |
| 1018 | * @param mixed $value |
| 1019 | * @param string $key |
| 1020 | * |
| 1021 | * @return string|int String/integer representation of value |
| 1022 | * @since 1.35 |
| 1023 | */ |
| 1024 | protected function getSerialized( $value, $key ) { |
| 1025 | $this->checkValueSerializability( $value, $key ); |
| 1026 | |
| 1027 | return $this->serialize( $value ); |
| 1028 | } |
| 1029 | |
| 1030 | /** |
| 1031 | * Log if a new cache value does not appear suitable for serialization at a quick glance |
| 1032 | * |
| 1033 | * This aids migration of values to JSON-like structures and the debugging of exceptions |
| 1034 | * due to serialization failure. |
| 1035 | * |
| 1036 | * This does not recurse more than one level into container structures. |
| 1037 | * |
| 1038 | * A proper cache key value is one of the following: |
| 1039 | * - null |
| 1040 | * - a scalar |
| 1041 | * - an array with scalar/null values |
| 1042 | * - an array tree with scalar/null "leaf" values |
| 1043 | * - an stdClass instance with scalar/null field values |
| 1044 | * - an stdClass instance tree with scalar/null "leaf" values |
| 1045 | * - an instance of a class that implements JsonSerializable |
| 1046 | * |
| 1047 | * @param mixed $value Result of the value generation callback for the key |
| 1048 | * @param string $key Cache key |
| 1049 | */ |
| 1050 | private function checkValueSerializability( $value, $key ) { |
| 1051 | if ( is_array( $value ) ) { |
| 1052 | $this->checkIterableMapSerializability( $value, $key ); |
| 1053 | } elseif ( is_object( $value ) ) { |
| 1054 | // Note that Closure instances count as objects |
| 1055 | if ( $value instanceof stdClass ) { |
| 1056 | $this->checkIterableMapSerializability( $value, $key ); |
| 1057 | } elseif ( !( $value instanceof JsonSerializable ) ) { |
| 1058 | $this->logger->warning( |
| 1059 | "{class} value for '{cachekey}'; serialization is suspect.", |
| 1060 | [ 'cachekey' => $key, 'class' => get_class( $value ) ] |
| 1061 | ); |
| 1062 | } |
| 1063 | } |
| 1064 | } |
| 1065 | |
| 1066 | /** |
| 1067 | * @param array|stdClass $value Result of the value generation callback for the key |
| 1068 | * @param string $key Cache key |
| 1069 | */ |
| 1070 | private function checkIterableMapSerializability( $value, $key ) { |
| 1071 | foreach ( $value as $index => $entry ) { |
| 1072 | if ( is_object( $entry ) ) { |
| 1073 | // Note that Closure instances count as objects |
| 1074 | if ( |
| 1075 | !( $entry instanceof \stdClass ) && |
| 1076 | !( $entry instanceof \JsonSerializable ) |
| 1077 | ) { |
| 1078 | $this->logger->warning( |
| 1079 | "{class} value for '{cachekey}' at '$index'; serialization is suspect.", |
| 1080 | [ 'cachekey' => $key, 'class' => get_class( $entry ) ] |
| 1081 | ); |
| 1082 | |
| 1083 | return; |
| 1084 | } |
| 1085 | } |
| 1086 | } |
| 1087 | } |
| 1088 | |
| 1089 | /** |
| 1090 | * @param mixed $value |
| 1091 | * |
| 1092 | * @return string|int|false String/integer representation |
| 1093 | * @note Special handling is usually needed for integers so incr()/decr() work |
| 1094 | */ |
| 1095 | protected function serialize( $value ) { |
| 1096 | return is_int( $value ) ? $value : serialize( $value ); |
| 1097 | } |
| 1098 | |
| 1099 | /** |
| 1100 | * @param string|int|false $value |
| 1101 | * |
| 1102 | * @return mixed Original value or false on error |
| 1103 | * @note Special handling is usually needed for integers so incr()/decr() work |
| 1104 | */ |
| 1105 | protected function unserialize( $value ) { |
| 1106 | return $this->isInteger( $value ) ? (int)$value : unserialize( $value ); |
| 1107 | } |
| 1108 | |
| 1109 | /** |
| 1110 | * @param string $text |
| 1111 | */ |
| 1112 | protected function debug( $text ) { |
| 1113 | $this->logger->debug( "{class} debug: $text", [ 'class' => static::class ] ); |
| 1114 | } |
| 1115 | |
| 1116 | /** |
| 1117 | * @param string $key Key generated by BagOStuff::makeKeyInternal |
| 1118 | * |
| 1119 | * @return string A stats prefix to describe this class of key (e.g. "objectcache.file") |
| 1120 | */ |
| 1121 | private function determinekeyGroupForStats( $key ): string { |
| 1122 | // Key came directly from BagOStuff::makeKey() or BagOStuff::makeGlobalKey() |
| 1123 | // and thus has the format of "<scope>:<collection>[:<constant or variable>]..." |
| 1124 | $components = explode( ':', $key, 3 ); |
| 1125 | // Handle legacy callers that fail to use the key building methods |
| 1126 | $keygroup = $components[1] ?? 'UNKNOWN'; |
| 1127 | |
| 1128 | return strtr( $keygroup, '.', '_' ); |
| 1129 | } |
| 1130 | |
| 1131 | /** |
| 1132 | * @param string $op Operation name as a MediumSpecificBagOStuff::METRIC_OP_* constant |
| 1133 | * @param array<int,string>|array<string,int[]> $keyInfo Key list, if payload sizes are not |
| 1134 | * applicable, otherwise, map of (key => (send payload size, receive payload size)); send |
| 1135 | * and receive sizes are 0 where not applicable and receive sizes are "false" for keys |
| 1136 | * that were not found during read operations |
| 1137 | */ |
| 1138 | protected function updateOpStats( string $op, array $keyInfo ) { |
| 1139 | $deltasByMetric = []; |
| 1140 | |
| 1141 | foreach ( $keyInfo as $indexOrKey => $keyOrSizes ) { |
| 1142 | if ( is_array( $keyOrSizes ) ) { |
| 1143 | $key = $indexOrKey; |
| 1144 | [ $sPayloadSize, $rPayloadSize ] = $keyOrSizes; |
| 1145 | } else { |
| 1146 | $key = $keyOrSizes; |
| 1147 | $sPayloadSize = 0; |
| 1148 | $rPayloadSize = 0; |
| 1149 | } |
| 1150 | |
| 1151 | // Metric prefix for the cache wrapper and key collection name |
| 1152 | $keygroup = $this->determinekeyGroupForStats( $key ); |
| 1153 | |
| 1154 | if ( $op === self::METRIC_OP_GET ) { |
| 1155 | // This operation was either a "hit" or "miss" for this key |
| 1156 | if ( $rPayloadSize === false ) { |
| 1157 | $statsName = "bagostuff_miss_total"; |
| 1158 | } else { |
| 1159 | $statsName = "bagostuff_hit_total"; |
| 1160 | } |
| 1161 | } else { |
| 1162 | // There is no concept of "hit" or "miss" for this operation |
| 1163 | $statsName = "bagostuff_call_total"; |
| 1164 | } |
| 1165 | $deltasByMetric[$statsName][$keygroup] = ( $deltasByMetric[$statsName][$keygroup] ?? 0 ) + 1; |
| 1166 | |
| 1167 | if ( $sPayloadSize > 0 ) { |
| 1168 | $statsName = "bagostuff_bytes_sent_total"; |
| 1169 | $deltasByMetric[$statsName][$keygroup] = |
| 1170 | ( $deltasByMetric[$statsName][$keygroup] ?? 0 ) + $sPayloadSize; |
| 1171 | } |
| 1172 | |
| 1173 | if ( $rPayloadSize > 0 ) { |
| 1174 | $statsName = "bagostuff_bytes_read_total"; |
| 1175 | $deltasByMetric[$statsName][$keygroup] = |
| 1176 | ( $deltasByMetric[$statsName][$keygroup] ?? 0 ) + $rPayloadSize; |
| 1177 | } |
| 1178 | } |
| 1179 | |
| 1180 | foreach ( $deltasByMetric as $statsName => $deltaByKeygroup ) { |
| 1181 | $stats = $this->stats->getCounter( $statsName ); |
| 1182 | foreach ( $deltaByKeygroup as $keygroup => $delta ) { |
| 1183 | $stats->setLabel( 'keygroup', $keygroup ) |
| 1184 | ->setLabel( 'operation', $op ) |
| 1185 | ->incrementBy( $delta ); |
| 1186 | } |
| 1187 | } |
| 1188 | } |
| 1189 | } |
| 1190 | |
| 1191 | /** @deprecated class alias since 1.43 */ |
| 1192 | class_alias( MediumSpecificBagOStuff::class, 'MediumSpecificBagOStuff' ); |