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         /**
  56          * Create the appropriate object to handle a specific job
  57          *
  58          * @param string $command Job command
  59          * @param array|Title $params Job parameters
  60          * @throws InvalidArgumentException
  61          * @return Job
  62          */
  63         public static function factory( $command, $params = [] ) {
  64                 global $wgJobClasses;
  65
  66                 if ( $params instanceof Title ) {
  67                         // Backwards compatibility for old signature ($command, $title, $params)
  68                         $title = $params;
  69                         $params = func_num_args() >= 3 ? func_get_arg( 2 ) : [];
  70                 } elseif ( isset( $params['namespace'] ) && isset( $params['title'] ) ) {
  71                         // Handle job classes that take title as constructor parameter.
  72                         // If a newer classes like GenericParameterJob uses these parameters,
  73                         // then this happens in Job::__construct instead.
  74                         $title = Title::makeTitle( $params['namespace'], $params['title'] );
  75                 } else {
  76                         // Default title for job classes not implementing GenericParameterJob.
  77                         // This must be a valid title because it not directly passed to
  78                         // our Job constructor, but rather it's subclasses which may expect
  79                         // to be able to use it.
  80                         $title = Title::makeTitle( NS_SPECIAL, 'Blankpage' );
  81                 }
  82
  83                 if ( isset( $wgJobClasses[$command] ) ) {
  84                         $handler = $wgJobClasses[$command];
  85
  86                         if ( is_callable( $handler ) ) {
  87                                 $job = call_user_func( $handler, $title, $params );
  88                         } elseif ( class_exists( $handler ) ) {
  89                                 if ( is_subclass_of( $handler, GenericParameterJob::class ) ) {
  90                                         $job = new $handler( $params );
  91                                 } else {
  92                                         $job = new $handler( $title, $params );
  93                                 }
  94                         } else {
  95                                 $job = null;
  96                         }
  97
  98                         if ( $job instanceof Job ) {
  99                                 $job->command = $command;
 100
 101                                 return $job;
 102                         } else {
 103                                 throw new InvalidArgumentException(
 104                                         "Could not instantiate job '$command': bad spec!"
 105                                 );
 106                         }
 107                 }
 108
 109                 throw new InvalidArgumentException( "Invalid job command '{$command}'" );
 110         }
 111
 112         /**
 113          * @param string $command
 114          * @param array|Title|null $params
 115          */
 116         public function __construct( $command, $params = null ) {
 117                 if ( $params instanceof Title ) {
 118                         // Backwards compatibility for old signature ($command, $title, $params)
 119                         $title = $params;
 120                         $params = func_num_args() >= 3 ? func_get_arg( 2 ) : [];
 121                 } else {
 122                         // Newer jobs may choose to not have a top-level title (e.g. GenericParameterJob)
 123                         $title = null;
 124                 }
 125
 126                 if ( !is_array( $params ) ) {
 127                         throw new InvalidArgumentException( '$params must be an array' );
 128                 }
 129
 130                 if (
 131                         $title &&
 132                         !isset( $params['namespace'] ) &&
 133                         !isset( $params['title'] )
 134                 ) {
 135                         // When constructing this class for submitting to the queue,
 136                         // normalise the $title arg of old job classes as part of $params.
 137                         $params['namespace'] = $title->getNamespace();
 138                         $params['title'] = $title->getDBkey();
 139                 }
 140
 141                 $this->command = $command;
 142                 $this->params = $params + [ 'requestId' => WebRequest::getRequestId() ];
 143
 144                 if ( $this->title === null ) {
 145                         // Set this field for access via getTitle().
 146                         $this->title = ( isset( $params['namespace'] ) && isset( $params['title'] ) )
 147                                 ? Title::makeTitle( $params['namespace'], $params['title'] )
 148                                 // GenericParameterJob classes without namespace/title params
 149                                 // should not use getTitle(). Set an invalid title as placeholder.
 150                                 : Title::makeTitle( NS_SPECIAL, '' );
 151                 }
 152         }
 153
 154         public function hasExecutionFlag( $flag ) {
 155                 return ( $this->executionFlags & $flag ) === $flag;
 156         }
 157
 158         /**
 159          * @return string
 160          */
 161         public function getType() {
 162                 return $this->command;
 163         }
 164
 165         /**
 166          * @return Title
 167          */
 168         final public function getTitle() {
 169                 return $this->title;
 170         }
 171
 172         /**
 173          * @return array
 174          */
 175         public function getParams() {
 176                 return $this->params;
 177         }
 178
 179         /**
 180          * @param string|null $field Metadata field or null to get all the metadata
 181          * @return mixed|null Value; null if missing
 182          * @since 1.33
 183          */
 184         public function getMetadata( $field = null ) {
 185                 if ( $field === null ) {
 186                         return $this->metadata;
 187                 }
 188
 189                 return $this->metadata[$field] ?? null;
 190         }
 191
 192         /**
 193          * @param string $field Key name to set the value for
 194          * @param mixed $value The value to set the field for
 195          * @return mixed|null The prior field value; null if missing
 196          * @since 1.33
 197          */
 198         public function setMetadata( $field, $value ) {
 199                 $old = $this->getMetadata( $field );
 200                 if ( $value === null ) {
 201                         unset( $this->metadata[$field] );
 202                 } else {
 203                         $this->metadata[$field] = $value;
 204                 }
 205
 206                 return $old;
 207         }
 208
 209         /**
 210          * @return int|null UNIX timestamp to delay running this job until, otherwise null
 211          * @since 1.22
 212          */
 213         public function getReleaseTimestamp() {
 214                 return isset( $this->params['jobReleaseTimestamp'] )
 215                         ? wfTimestampOrNull( TS_UNIX, $this->params['jobReleaseTimestamp'] )
 216                         : null;
 217         }
 218
 219         /**
 220          * @return int|null UNIX timestamp of when the job was queued, or null
 221          * @since 1.26
 222          */
 223         public function getQueuedTimestamp() {
 224                 return isset( $this->metadata['timestamp'] )
 225                         ? wfTimestampOrNull( TS_UNIX, $this->metadata['timestamp'] )
 226                         : null;
 227         }
 228
 229         public function getRequestId() {
 230                 return $this->params['requestId'] ?? null;
 231         }
 232
 233         public function getReadyTimestamp() {
 234                 return $this->getReleaseTimestamp() ?: $this->getQueuedTimestamp();
 235         }
 236
 237         /**
 238          * Whether the queue should reject insertion of this job if a duplicate exists
 239          *
 240          * This can be used to avoid duplicated effort or combined with delayed jobs to
 241          * coalesce updates into larger batches. Claimed jobs are never treated as
 242          * duplicates of new jobs, and some queues may allow a few duplicates due to
 243          * network partitions and fail-over. Thus, additional locking is needed to
 244          * enforce mutual exclusion if this is really needed.
 245          *
 246          * @return bool
 247          */
 248         public function ignoreDuplicates() {
 249                 return $this->removeDuplicates;
 250         }
 251
 252         public function allowRetries() {
 253                 return true;
 254         }
 255
 256         public function workItemCount() {
 257                 return 1;
 258         }
 259
 260         /**
 261          * Subclasses may need to override this to make duplication detection work.
 262          * The resulting map conveys everything that makes the job unique. This is
 263          * only checked if ignoreDuplicates() returns true, meaning that duplicate
 264          * jobs are supposed to be ignored.
 265          *
 266          * @return array Map of key/values
 267          * @since 1.21
 268          */
 269         public function getDeduplicationInfo() {
 270                 $info = [
 271                         'type' => $this->getType(),
 272                         'params' => $this->getParams()
 273                 ];
 274                 if ( is_array( $info['params'] ) ) {
 275                         // Identical jobs with different "root" jobs should count as duplicates
 276                         unset( $info['params']['rootJobSignature'] );
 277                         unset( $info['params']['rootJobTimestamp'] );
 278                         // Likewise for jobs with different delay times
 279                         unset( $info['params']['jobReleaseTimestamp'] );
 280                         // Identical jobs from different requests should count as duplicates
 281                         unset( $info['params']['requestId'] );
 282                         // Queues pack and hash this array, so normalize the order
 283                         ksort( $info['params'] );
 284                 }
 285
 286                 return $info;
 287         }
 288
 289         /**
 290          * Get "root job" parameters for a task
 291          *
 292          * This is used to no-op redundant jobs, including child jobs of jobs,
 293          * as long as the children inherit the root job parameters. When a job
 294          * with root job parameters and "rootJobIsSelf" set is pushed, the
 295          * deduplicateRootJob() method is automatically called on it. If the
 296          * root job is only virtual and not actually pushed (e.g. the sub-jobs
 297          * are inserted directly), then call deduplicateRootJob() directly.
 298          *
 299          * @see JobQueue::deduplicateRootJob()
 300          *
 301          * @param string $key A key that identifies the task
 302          * @return array Map of:
 303          *   - rootJobIsSelf    : true
 304          *   - rootJobSignature : hash (e.g. SHA1) that identifies the task
 305          *   - rootJobTimestamp : TS_MW timestamp of this instance of the task
 306          * @since 1.21
 307          */
 308         public static function newRootJobParams( $key ) {
 309                 return [
 310                         'rootJobIsSelf'    => true,
 311                         'rootJobSignature' => sha1( $key ),
 312                         'rootJobTimestamp' => wfTimestampNow()
 313                 ];
 314         }
 315
 316         /**
 317          * @see JobQueue::deduplicateRootJob()
 318          * @return array
 319          * @since 1.21
 320          */
 321         public function getRootJobParams() {
 322                 return [
 323                         'rootJobSignature' => $this->params['rootJobSignature'] ?? null,
 324                         'rootJobTimestamp' => $this->params['rootJobTimestamp'] ?? null
 325                 ];
 326         }
 327
 328         /**
 329          * @see JobQueue::deduplicateRootJob()
 330          * @return bool
 331          * @since 1.22
 332          */
 333         public function hasRootJobParams() {
 334                 return isset( $this->params['rootJobSignature'] )
 335                         && isset( $this->params['rootJobTimestamp'] );
 336         }
 337
 338         /**
 339          * @see JobQueue::deduplicateRootJob()
 340          * @return bool Whether this is job is a root job
 341          */
 342         public function isRootJob() {
 343                 return $this->hasRootJobParams() && !empty( $this->params['rootJobIsSelf'] );
 344         }
 345
 346         /**
 347          * @param callable $callback A function with one parameter, the success status, which will be
 348          *   false if the job failed or it succeeded but the DB changes could not be committed or
 349          *   any deferred updates threw an exception. (This parameter was added in 1.28.)
 350          * @since 1.27
 351          */
 352         protected function addTeardownCallback( $callback ) {
 353                 $this->teardownCallbacks[] = $callback;
 354         }
 355
 356         public function teardown( $status ) {
 357                 foreach ( $this->teardownCallbacks as $callback ) {
 358                         call_user_func( $callback, $status );
 359                 }
 360         }
 361
 362         public function toString() {
 363                 $paramString = '';
 364                 if ( $this->params ) {
 365                         foreach ( $this->params as $key => $value ) {
 366                                 if ( $paramString != '' ) {
 367                                         $paramString .= ' ';
 368                                 }
 369                                 if ( is_array( $value ) ) {
 370                                         $filteredValue = [];
 371                                         foreach ( $value as $k => $v ) {
 372                                                 $json = FormatJson::encode( $v );
 373                                                 if ( $json === false || mb_strlen( $json ) > 512 ) {
 374                                                         $filteredValue[$k] = gettype( $v ) . '(...)';
 375                                                 } else {
 376                                                         $filteredValue[$k] = $v;
 377                                                 }
 378                                         }
 379                                         if ( count( $filteredValue ) <= 10 ) {
 380                                                 $value = FormatJson::encode( $filteredValue );
 381                                         } else {
 382                                                 $value = "array(" . count( $value ) . ")";
 383                                         }
 384                                 } elseif ( is_object( $value ) && !method_exists( $value, '__toString' ) ) {
 385                                         $value = "object(" . get_class( $value ) . ")";
 386                                 }
 387
 388                                 $flatValue = (string)$value;
 389                                 if ( mb_strlen( $value ) > 1024 ) {
 390                                         $flatValue = "string(" . mb_strlen( $value ) . ")";
 391                                 }
 392
 393                                 $paramString .= "$key={$flatValue}";
 394                         }
 395                 }
 396
 397                 $metaString = '';
 398                 foreach ( $this->metadata as $key => $value ) {
 399                         if ( is_scalar( $value ) && mb_strlen( $value ) < 1024 ) {
 400                                 $metaString .= ( $metaString ? ",$key=$value" : "$key=$value" );
 401                         }
 402                 }
 403
 404                 $s = $this->command;
 405                 if ( is_object( $this->title ) ) {
 406                         $s .= " {$this->title->getPrefixedDBkey()}";
 407                 }
 408                 if ( $paramString != '' ) {
 409                         $s .= " $paramString";
 410                 }
 411                 if ( $metaString != '' ) {
 412                         $s .= " ($metaString)";
 413                 }
 414
 415                 return $s;
 416         }
 417
 418         protected function setLastError( $error ) {
 419                 $this->error = $error;
 420         }
 421
 422         public function getLastError() {
 423                 return $this->error;
 424         }
 425 }