includes/jobqueue/Job.php

   1 <?php
   2 /**
   3  * Job queue task base code.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @defgroup JobQueue JobQueue
  22  */
  23
  24 /**
  25  * Class to both describe a background job and handle jobs.
  26  * To push jobs onto queues, use JobQueueGroup::singleton()->push();
  27  *
  28  * @ingroup JobQueue
  29  */
  30 abstract class Job implements RunnableJob {
  31         /** @var string */
  32         public $command;
  33
  34         /** @var array Array of job parameters */
  35         public $params;
  36
  37         /** @var array Additional queue metadata */
  38         public $metadata = [];
  39
  40         /** @var Title */
  41         protected $title;
  42
  43         /** @var bool Expensive jobs may set this to true */
  44         protected $removeDuplicates = false;
  45
  46         /** @var string Text for error that occurred last */
  47         protected $error;
  48
  49         /** @var callable[] */
  50         protected $teardownCallbacks = [];
  51
  52         /** @var int Bitfield of JOB_* class constants */
  53         protected $executionFlags = 0;
  54
  55         /** @var int Job must not be wrapped in the usual explicit LBFactory transaction round */
  56         const JOB_NO_EXPLICIT_TRX_ROUND = 1;
  57
  58         /**
  59          * Create the appropriate object to handle a specific job
  60          *
  61          * @param string $command Job command
  62          * @param array|Title $params Job parameters
  63          * @throws InvalidArgumentException
  64          * @return Job
  65          */
  66         public static function factory( $command, $params = [] ) {
  67                 global $wgJobClasses;
  68
  69                 if ( $params instanceof Title ) {
  70                         // Backwards compatibility for old signature ($command, $title, $params)
  71                         $title = $params;
  72                         $params = func_num_args() >= 3 ? func_get_arg( 2 ) : [];
  73                 } elseif ( isset( $params['namespace'] ) && isset( $params['title'] ) ) {
  74                         // Handle job classes that take title as constructor parameter.
  75                         // If a newer classes like GenericParameterJob uses these parameters,
  76                         // then this happens in Job::__construct instead.
  77                         $title = Title::makeTitle( $params['namespace'], $params['title'] );
  78                 } else {
  79                         // Default title for job classes not implementing GenericParameterJob.
  80                         // This must be a valid title because it not directly passed to
  81                         // our Job constructor, but rather it's subclasses which may expect
  82                         // to be able to use it.
  83                         $title = Title::makeTitle( NS_SPECIAL, 'Blankpage' );
  84                 }
  85
  86                 if ( isset( $wgJobClasses[$command] ) ) {
  87                         $handler = $wgJobClasses[$command];
  88
  89                         if ( is_callable( $handler ) ) {
  90                                 $job = call_user_func( $handler, $title, $params );
  91                         } elseif ( class_exists( $handler ) ) {
  92                                 if ( is_subclass_of( $handler, GenericParameterJob::class ) ) {
  93                                         $job = new $handler( $params );
  94                                 } else {
  95                                         $job = new $handler( $title, $params );
  96                                 }
  97                         } else {
  98                                 $job = null;
  99                         }
 100
 101                         if ( $job instanceof Job ) {
 102                                 $job->command = $command;
 103
 104                                 return $job;
 105                         } else {
 106                                 throw new InvalidArgumentException( "Could instantiate job '$command': bad spec!" );
 107                         }
 108                 }
 109
 110                 throw new InvalidArgumentException( "Invalid job command '{$command}'" );
 111         }
 112
 113         /**
 114          * @param string $command
 115          * @param array|Title|null $params
 116          */
 117         public function __construct( $command, $params = null ) {
 118                 if ( $params instanceof Title ) {
 119                         // Backwards compatibility for old signature ($command, $title, $params)
 120                         $title = $params;
 121                         $params = func_num_args() >= 3 ? func_get_arg( 2 ) : [];
 122                 } else {
 123                         // Newer jobs may choose to not have a top-level title (e.g. GenericParameterJob)
 124                         $title = null;
 125                 }
 126
 127                 if ( !is_array( $params ) ) {
 128                         throw new InvalidArgumentException( '$params must be an array' );
 129                 }
 130
 131                 if (
 132                         $title &&
 133                         !isset( $params['namespace'] ) &&
 134                         !isset( $params['title'] )
 135                 ) {
 136                         // When constructing this class for submitting to the queue,
 137                         // normalise the $title arg of old job classes as part of $params.
 138                         $params['namespace'] = $title->getNamespace();
 139                         $params['title'] = $title->getDBKey();
 140                 }
 141
 142                 $this->command = $command;
 143                 $this->params = $params + [ 'requestId' => WebRequest::getRequestId() ];
 144
 145                 if ( $this->title === null ) {
 146                         // Set this field for access via getTitle().
 147                         $this->title = ( isset( $params['namespace'] ) && isset( $params['title'] ) )
 148                                 ? Title::makeTitle( $params['namespace'], $params['title'] )
 149                                 // GenericParameterJob classes without namespace/title params
 150                                 // should not use getTitle(). Set an invalid title as placeholder.
 151                                 : Title::makeTitle( NS_SPECIAL, '' );
 152                 }
 153         }
 154
 155         /**
 156          * @param int $flag JOB_* class constant
 157          * @return bool
 158          * @since 1.31
 159          */
 160         public function hasExecutionFlag( $flag ) {
 161                 return ( $this->executionFlags & $flag ) === $flag;
 162         }
 163
 164         /**
 165          * @return string
 166          */
 167         public function getType() {
 168                 return $this->command;
 169         }
 170
 171         /**
 172          * @return Title
 173          */
 174         final public function getTitle() {
 175                 return $this->title;
 176         }
 177
 178         /**
 179          * @return array
 180          */
 181         public function getParams() {
 182                 return $this->params;
 183         }
 184
 185         /**
 186          * @param string|null $field Metadata field or null to get all the metadata
 187          * @return mixed|null Value; null if missing
 188          * @since 1.33
 189          */
 190         public function getMetadata( $field = null ) {
 191                 if ( $field === null ) {
 192                         return $this->metadata;
 193                 }
 194
 195                 return $this->metadata[$field] ?? null;
 196         }
 197
 198         /**
 199          * @param string $field Key name to set the value for
 200          * @param mixed $value The value to set the field for
 201          * @return mixed|null The prior field value; null if missing
 202          * @since 1.33
 203          */
 204         public function setMetadata( $field, $value ) {
 205                 $old = $this->getMetadata( $field );
 206                 if ( $value === null ) {
 207                         unset( $this->metadata[$field] );
 208                 } else {
 209                         $this->metadata[$field] = $value;
 210                 }
 211
 212                 return $old;
 213         }
 214
 215         /**
 216          * @return int|null UNIX timestamp to delay running this job until, otherwise null
 217          * @since 1.22
 218          */
 219         public function getReleaseTimestamp() {
 220                 return isset( $this->params['jobReleaseTimestamp'] )
 221                         ? wfTimestampOrNull( TS_UNIX, $this->params['jobReleaseTimestamp'] )
 222                         : null;
 223         }
 224
 225         /**
 226          * @return int|null UNIX timestamp of when the job was queued, or null
 227          * @since 1.26
 228          */
 229         public function getQueuedTimestamp() {
 230                 return isset( $this->metadata['timestamp'] )
 231                         ? wfTimestampOrNull( TS_UNIX, $this->metadata['timestamp'] )
 232                         : null;
 233         }
 234
 235         /**
 236          * @return string|null Id of the request that created this job. Follows
 237          *  jobs recursively, allowing to track the id of the request that started a
 238          *  job when jobs insert jobs which insert other jobs.
 239          * @since 1.27
 240          */
 241         public function getRequestId() {
 242                 return $this->params['requestId'] ?? null;
 243         }
 244
 245         /**
 246          * @return int|null UNIX timestamp of when the job was runnable, or null
 247          * @since 1.26
 248          */
 249         public function getReadyTimestamp() {
 250                 return $this->getReleaseTimestamp() ?: $this->getQueuedTimestamp();
 251         }
 252
 253         /**
 254          * Whether the queue should reject insertion of this job if a duplicate exists
 255          *
 256          * This can be used to avoid duplicated effort or combined with delayed jobs to
 257          * coalesce updates into larger batches. Claimed jobs are never treated as
 258          * duplicates of new jobs, and some queues may allow a few duplicates due to
 259          * network partitions and fail-over. Thus, additional locking is needed to
 260          * enforce mutual exclusion if this is really needed.
 261          *
 262          * @return bool
 263          */
 264         public function ignoreDuplicates() {
 265                 return $this->removeDuplicates;
 266         }
 267
 268         /**
 269          * @return bool Whether this job can be retried on failure by job runners
 270          * @since 1.21
 271          */
 272         public function allowRetries() {
 273                 return true;
 274         }
 275
 276         /**
 277          * @return int Number of actually "work items" handled in this job
 278          * @see $wgJobBackoffThrottling
 279          * @since 1.23
 280          */
 281         public function workItemCount() {
 282                 return 1;
 283         }
 284
 285         /**
 286          * Subclasses may need to override this to make duplication detection work.
 287          * The resulting map conveys everything that makes the job unique. This is
 288          * only checked if ignoreDuplicates() returns true, meaning that duplicate
 289          * jobs are supposed to be ignored.
 290          *
 291          * @return array Map of key/values
 292          * @since 1.21
 293          */
 294         public function getDeduplicationInfo() {
 295                 $info = [
 296                         'type' => $this->getType(),
 297                         'params' => $this->getParams()
 298                 ];
 299                 if ( is_array( $info['params'] ) ) {
 300                         // Identical jobs with different "root" jobs should count as duplicates
 301                         unset( $info['params']['rootJobSignature'] );
 302                         unset( $info['params']['rootJobTimestamp'] );
 303                         // Likewise for jobs with different delay times
 304                         unset( $info['params']['jobReleaseTimestamp'] );
 305                         // Identical jobs from different requests should count as duplicates
 306                         unset( $info['params']['requestId'] );
 307                         // Queues pack and hash this array, so normalize the order
 308                         ksort( $info['params'] );
 309                 }
 310
 311                 return $info;
 312         }
 313
 314         /**
 315          * Get "root job" parameters for a task
 316          *
 317          * This is used to no-op redundant jobs, including child jobs of jobs,
 318          * as long as the children inherit the root job parameters. When a job
 319          * with root job parameters and "rootJobIsSelf" set is pushed, the
 320          * deduplicateRootJob() method is automatically called on it. If the
 321          * root job is only virtual and not actually pushed (e.g. the sub-jobs
 322          * are inserted directly), then call deduplicateRootJob() directly.
 323          *
 324          * @see JobQueue::deduplicateRootJob()
 325          *
 326          * @param string $key A key that identifies the task
 327          * @return array Map of:
 328          *   - rootJobIsSelf    : true
 329          *   - rootJobSignature : hash (e.g. SHA1) that identifies the task
 330          *   - rootJobTimestamp : TS_MW timestamp of this instance of the task
 331          * @since 1.21
 332          */
 333         public static function newRootJobParams( $key ) {
 334                 return [
 335                         'rootJobIsSelf'    => true,
 336                         'rootJobSignature' => sha1( $key ),
 337                         'rootJobTimestamp' => wfTimestampNow()
 338                 ];
 339         }
 340
 341         /**
 342          * @see JobQueue::deduplicateRootJob()
 343          * @return array
 344          * @since 1.21
 345          */
 346         public function getRootJobParams() {
 347                 return [
 348                         'rootJobSignature' => $this->params['rootJobSignature'] ?? null,
 349                         'rootJobTimestamp' => $this->params['rootJobTimestamp'] ?? null
 350                 ];
 351         }
 352
 353         /**
 354          * @see JobQueue::deduplicateRootJob()
 355          * @return bool
 356          * @since 1.22
 357          */
 358         public function hasRootJobParams() {
 359                 return isset( $this->params['rootJobSignature'] )
 360                         && isset( $this->params['rootJobTimestamp'] );
 361         }
 362
 363         /**
 364          * @see JobQueue::deduplicateRootJob()
 365          * @return bool Whether this is job is a root job
 366          */
 367         public function isRootJob() {
 368                 return $this->hasRootJobParams() && !empty( $this->params['rootJobIsSelf'] );
 369         }
 370
 371         /**
 372          * @param callable $callback A function with one parameter, the success status, which will be
 373          *   false if the job failed or it succeeded but the DB changes could not be committed or
 374          *   any deferred updates threw an exception. (This parameter was added in 1.28.)
 375          * @since 1.27
 376          */
 377         protected function addTeardownCallback( $callback ) {
 378                 $this->teardownCallbacks[] = $callback;
 379         }
 380
 381         /**
 382          * Do any final cleanup after run(), deferred updates, and all DB commits happen
 383          * @param bool $status Whether the job, its deferred updates, and DB commit all succeeded
 384          * @since 1.27
 385          */
 386         public function teardown( $status ) {
 387                 foreach ( $this->teardownCallbacks as $callback ) {
 388                         call_user_func( $callback, $status );
 389                 }
 390         }
 391
 392         /**
 393          * @return string
 394          */
 395         public function toString() {
 396                 $paramString = '';
 397                 if ( $this->params ) {
 398                         foreach ( $this->params as $key => $value ) {
 399                                 if ( $paramString != '' ) {
 400                                         $paramString .= ' ';
 401                                 }
 402                                 if ( is_array( $value ) ) {
 403                                         $filteredValue = [];
 404                                         foreach ( $value as $k => $v ) {
 405                                                 $json = FormatJson::encode( $v );
 406                                                 if ( $json === false || mb_strlen( $json ) > 512 ) {
 407                                                         $filteredValue[$k] = gettype( $v ) . '(...)';
 408                                                 } else {
 409                                                         $filteredValue[$k] = $v;
 410                                                 }
 411                                         }
 412                                         if ( count( $filteredValue ) <= 10 ) {
 413                                                 $value = FormatJson::encode( $filteredValue );
 414                                         } else {
 415                                                 $value = "array(" . count( $value ) . ")";
 416                                         }
 417                                 } elseif ( is_object( $value ) && !method_exists( $value, '__toString' ) ) {
 418                                         $value = "object(" . get_class( $value ) . ")";
 419                                 }
 420
 421                                 $flatValue = (string)$value;
 422                                 if ( mb_strlen( $value ) > 1024 ) {
 423                                         $flatValue = "string(" . mb_strlen( $value ) . ")";
 424                                 }
 425
 426                                 $paramString .= "$key={$flatValue}";
 427                         }
 428                 }
 429
 430                 $metaString = '';
 431                 foreach ( $this->metadata as $key => $value ) {
 432                         if ( is_scalar( $value ) && mb_strlen( $value ) < 1024 ) {
 433                                 $metaString .= ( $metaString ? ",$key=$value" : "$key=$value" );
 434                         }
 435                 }
 436
 437                 $s = $this->command;
 438                 if ( is_object( $this->title ) ) {
 439                         $s .= " {$this->title->getPrefixedDBkey()}";
 440                 }
 441                 if ( $paramString != '' ) {
 442                         $s .= " $paramString";
 443                 }
 444                 if ( $metaString != '' ) {
 445                         $s .= " ($metaString)";
 446                 }
 447
 448                 return $s;
 449         }
 450
 451         protected function setLastError( $error ) {
 452                 $this->error = $error;
 453         }
 454
 455         public function getLastError() {
 456                 return $this->error;
 457         }
 458 }