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                 } else {
  74                         $title = ( isset( $params['namespace'] ) && isset( $params['title'] ) )
  75                                 ? Title::makeTitle( $params['namespace'], $params['title'] )
  76                                 : Title::makeTitle( NS_SPECIAL, '' );
  77                 }
  78
  79                 $params = is_array( $params ) ? $params : []; // sanity
  80
  81                 if ( isset( $wgJobClasses[$command] ) ) {
  82                         $handler = $wgJobClasses[$command];
  83
  84                         if ( is_callable( $handler ) ) {
  85                                 $job = call_user_func( $handler, $title, $params );
  86                         } elseif ( class_exists( $handler ) ) {
  87                                 if ( is_subclass_of( $handler, GenericParameterJob::class ) ) {
  88                                         $job = new $handler( $params );
  89                                 } else {
  90                                         $job = new $handler( $title, $params );
  91                                 }
  92                         } else {
  93                                 $job = null;
  94                         }
  95
  96                         if ( $job instanceof Job ) {
  97                                 $job->command = $command;
  98
  99                                 return $job;
 100                         } else {
 101                                 throw new InvalidArgumentException( "Could instantiate job '$command': bad spec!" );
 102                         }
 103                 }
 104
 105                 throw new InvalidArgumentException( "Invalid job command '{$command}'" );
 106         }
 107
 108         /**
 109          * @param string $command
 110          * @param array|Title|null $params
 111          */
 112         public function __construct( $command, $params = null ) {
 113                 if ( $params instanceof Title ) {
 114                         // Backwards compatibility for old signature ($command, $title, $params)
 115                         $title = $params;
 116                         $params = func_num_args() >= 3 ? func_get_arg( 2 ) : [];
 117                         $params = is_array( $params ) ? $params : []; // sanity
 118                         // Set namespace/title params if both are missing and this is not a dummy title
 119                         if (
 120                                 $title->getDBkey() !== '' &&
 121                                 !isset( $params['namespace'] ) &&
 122                                 !isset( $params['title'] )
 123                         ) {
 124                                 $params['namespace'] = $title->getNamespace();
 125                                 $params['title'] = $title->getDBKey();
 126                                 // Note that JobQueue classes will prefer the parameters over getTitle()
 127                                 $this->title = $title;
 128                         }
 129                 }
 130
 131                 $this->command = $command;
 132                 $this->params = $params + [ 'requestId' => WebRequest::getRequestId() ];
 133                 if ( $this->title === null ) {
 134                         $this->title = ( isset( $params['namespace'] ) && isset( $params['title'] ) )
 135                                 ? Title::makeTitle( $params['namespace'], $params['title'] )
 136                                 : Title::makeTitle( NS_SPECIAL, '' );
 137                 }
 138         }
 139
 140         /**
 141          * @param int $flag JOB_* class constant
 142          * @return bool
 143          * @since 1.31
 144          */
 145         public function hasExecutionFlag( $flag ) {
 146                 return ( $this->executionFlags & $flag ) === $flag;
 147         }
 148
 149         /**
 150          * @return string
 151          */
 152         public function getType() {
 153                 return $this->command;
 154         }
 155
 156         /**
 157          * @return Title
 158          */
 159         final public function getTitle() {
 160                 return $this->title;
 161         }
 162
 163         /**
 164          * @return array
 165          */
 166         public function getParams() {
 167                 return $this->params;
 168         }
 169
 170         /**
 171          * @param string|null $field Metadata field or null to get all the metadata
 172          * @return mixed|null Value; null if missing
 173          * @since 1.33
 174          */
 175         public function getMetadata( $field = null ) {
 176                 if ( $field === null ) {
 177                         return $this->metadata;
 178                 }
 179
 180                 return $this->metadata[$field] ?? null;
 181         }
 182
 183         /**
 184          * @param string $field Key name to set the value for
 185          * @param mixed $value The value to set the field for
 186          * @return mixed|null The prior field value; null if missing
 187          * @since 1.33
 188          */
 189         public function setMetadata( $field, $value ) {
 190                 $old = $this->getMetadata( $field );
 191                 if ( $value === null ) {
 192                         unset( $this->metadata[$field] );
 193                 } else {
 194                         $this->metadata[$field] = $value;
 195                 }
 196
 197                 return $old;
 198         }
 199
 200         /**
 201          * @return int|null UNIX timestamp to delay running this job until, otherwise null
 202          * @since 1.22
 203          */
 204         public function getReleaseTimestamp() {
 205                 return isset( $this->params['jobReleaseTimestamp'] )
 206                         ? wfTimestampOrNull( TS_UNIX, $this->params['jobReleaseTimestamp'] )
 207                         : null;
 208         }
 209
 210         /**
 211          * @return int|null UNIX timestamp of when the job was queued, or null
 212          * @since 1.26
 213          */
 214         public function getQueuedTimestamp() {
 215                 return isset( $this->metadata['timestamp'] )
 216                         ? wfTimestampOrNull( TS_UNIX, $this->metadata['timestamp'] )
 217                         : null;
 218         }
 219
 220         /**
 221          * @return string|null Id of the request that created this job. Follows
 222          *  jobs recursively, allowing to track the id of the request that started a
 223          *  job when jobs insert jobs which insert other jobs.
 224          * @since 1.27
 225          */
 226         public function getRequestId() {
 227                 return $this->params['requestId'] ?? null;
 228         }
 229
 230         /**
 231          * @return int|null UNIX timestamp of when the job was runnable, or null
 232          * @since 1.26
 233          */
 234         public function getReadyTimestamp() {
 235                 return $this->getReleaseTimestamp() ?: $this->getQueuedTimestamp();
 236         }
 237
 238         /**
 239          * Whether the queue should reject insertion of this job if a duplicate exists
 240          *
 241          * This can be used to avoid duplicated effort or combined with delayed jobs to
 242          * coalesce updates into larger batches. Claimed jobs are never treated as
 243          * duplicates of new jobs, and some queues may allow a few duplicates due to
 244          * network partitions and fail-over. Thus, additional locking is needed to
 245          * enforce mutual exclusion if this is really needed.
 246          *
 247          * @return bool
 248          */
 249         public function ignoreDuplicates() {
 250                 return $this->removeDuplicates;
 251         }
 252
 253         /**
 254          * @return bool Whether this job can be retried on failure by job runners
 255          * @since 1.21
 256          */
 257         public function allowRetries() {
 258                 return true;
 259         }
 260
 261         /**
 262          * @return int Number of actually "work items" handled in this job
 263          * @see $wgJobBackoffThrottling
 264          * @since 1.23
 265          */
 266         public function workItemCount() {
 267                 return 1;
 268         }
 269
 270         /**
 271          * Subclasses may need to override this to make duplication detection work.
 272          * The resulting map conveys everything that makes the job unique. This is
 273          * only checked if ignoreDuplicates() returns true, meaning that duplicate
 274          * jobs are supposed to be ignored.
 275          *
 276          * @return array Map of key/values
 277          * @since 1.21
 278          */
 279         public function getDeduplicationInfo() {
 280                 $info = [
 281                         'type' => $this->getType(),
 282                         'params' => $this->getParams()
 283                 ];
 284                 if ( is_array( $info['params'] ) ) {
 285                         // Identical jobs with different "root" jobs should count as duplicates
 286                         unset( $info['params']['rootJobSignature'] );
 287                         unset( $info['params']['rootJobTimestamp'] );
 288                         // Likewise for jobs with different delay times
 289                         unset( $info['params']['jobReleaseTimestamp'] );
 290                         // Identical jobs from different requests should count as duplicates
 291                         unset( $info['params']['requestId'] );
 292                         // Queues pack and hash this array, so normalize the order
 293                         ksort( $info['params'] );
 294                 }
 295
 296                 return $info;
 297         }
 298
 299         /**
 300          * Get "root job" parameters for a task
 301          *
 302          * This is used to no-op redundant jobs, including child jobs of jobs,
 303          * as long as the children inherit the root job parameters. When a job
 304          * with root job parameters and "rootJobIsSelf" set is pushed, the
 305          * deduplicateRootJob() method is automatically called on it. If the
 306          * root job is only virtual and not actually pushed (e.g. the sub-jobs
 307          * are inserted directly), then call deduplicateRootJob() directly.
 308          *
 309          * @see JobQueue::deduplicateRootJob()
 310          *
 311          * @param string $key A key that identifies the task
 312          * @return array Map of:
 313          *   - rootJobIsSelf    : true
 314          *   - rootJobSignature : hash (e.g. SHA1) that identifies the task
 315          *   - rootJobTimestamp : TS_MW timestamp of this instance of the task
 316          * @since 1.21
 317          */
 318         public static function newRootJobParams( $key ) {
 319                 return [
 320                         'rootJobIsSelf'    => true,
 321                         'rootJobSignature' => sha1( $key ),
 322                         'rootJobTimestamp' => wfTimestampNow()
 323                 ];
 324         }
 325
 326         /**
 327          * @see JobQueue::deduplicateRootJob()
 328          * @return array
 329          * @since 1.21
 330          */
 331         public function getRootJobParams() {
 332                 return [
 333                         'rootJobSignature' => $this->params['rootJobSignature'] ?? null,
 334                         'rootJobTimestamp' => $this->params['rootJobTimestamp'] ?? null
 335                 ];
 336         }
 337
 338         /**
 339          * @see JobQueue::deduplicateRootJob()
 340          * @return bool
 341          * @since 1.22
 342          */
 343         public function hasRootJobParams() {
 344                 return isset( $this->params['rootJobSignature'] )
 345                         && isset( $this->params['rootJobTimestamp'] );
 346         }
 347
 348         /**
 349          * @see JobQueue::deduplicateRootJob()
 350          * @return bool Whether this is job is a root job
 351          */
 352         public function isRootJob() {
 353                 return $this->hasRootJobParams() && !empty( $this->params['rootJobIsSelf'] );
 354         }
 355
 356         /**
 357          * @param callable $callback A function with one parameter, the success status, which will be
 358          *   false if the job failed or it succeeded but the DB changes could not be committed or
 359          *   any deferred updates threw an exception. (This parameter was added in 1.28.)
 360          * @since 1.27
 361          */
 362         protected function addTeardownCallback( $callback ) {
 363                 $this->teardownCallbacks[] = $callback;
 364         }
 365
 366         /**
 367          * Do any final cleanup after run(), deferred updates, and all DB commits happen
 368          * @param bool $status Whether the job, its deferred updates, and DB commit all succeeded
 369          * @since 1.27
 370          */
 371         public function teardown( $status ) {
 372                 foreach ( $this->teardownCallbacks as $callback ) {
 373                         call_user_func( $callback, $status );
 374                 }
 375         }
 376
 377         /**
 378          * @return string
 379          */
 380         public function toString() {
 381                 $paramString = '';
 382                 if ( $this->params ) {
 383                         foreach ( $this->params as $key => $value ) {
 384                                 if ( $paramString != '' ) {
 385                                         $paramString .= ' ';
 386                                 }
 387                                 if ( is_array( $value ) ) {
 388                                         $filteredValue = [];
 389                                         foreach ( $value as $k => $v ) {
 390                                                 $json = FormatJson::encode( $v );
 391                                                 if ( $json === false || mb_strlen( $json ) > 512 ) {
 392                                                         $filteredValue[$k] = gettype( $v ) . '(...)';
 393                                                 } else {
 394                                                         $filteredValue[$k] = $v;
 395                                                 }
 396                                         }
 397                                         if ( count( $filteredValue ) <= 10 ) {
 398                                                 $value = FormatJson::encode( $filteredValue );
 399                                         } else {
 400                                                 $value = "array(" . count( $value ) . ")";
 401                                         }
 402                                 } elseif ( is_object( $value ) && !method_exists( $value, '__toString' ) ) {
 403                                         $value = "object(" . get_class( $value ) . ")";
 404                                 }
 405
 406                                 $flatValue = (string)$value;
 407                                 if ( mb_strlen( $value ) > 1024 ) {
 408                                         $flatValue = "string(" . mb_strlen( $value ) . ")";
 409                                 }
 410
 411                                 $paramString .= "$key={$flatValue}";
 412                         }
 413                 }
 414
 415                 $metaString = '';
 416                 foreach ( $this->metadata as $key => $value ) {
 417                         if ( is_scalar( $value ) && mb_strlen( $value ) < 1024 ) {
 418                                 $metaString .= ( $metaString ? ",$key=$value" : "$key=$value" );
 419                         }
 420                 }
 421
 422                 $s = $this->command;
 423                 if ( is_object( $this->title ) ) {
 424                         $s .= " {$this->title->getPrefixedDBkey()}";
 425                 }
 426                 if ( $paramString != '' ) {
 427                         $s .= " $paramString";
 428                 }
 429                 if ( $metaString != '' ) {
 430                         $s .= " ($metaString)";
 431                 }
 432
 433                 return $s;
 434         }
 435
 436         protected function setLastError( $error ) {
 437                 $this->error = $error;
 438         }
 439
 440         public function getLastError() {
 441                 return $this->error;
 442         }
 443 }