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  * The queue aspects of this class are now deprecated.
  27  * Using the class to push jobs onto queues is deprecated (use JobSpecification).
  28  *
  29  * @ingroup JobQueue
  30  */
  31 abstract class Job implements IJobSpecification {
  32         /** @var string */
  33         public $command;
  34
  35         /** @var array Array of job parameters */
  36         public $params;
  37
  38         /** @var array Additional queue metadata */
  39         public $metadata = [];
  40
  41         /** @var Title */
  42         protected $title;
  43
  44         /** @var bool Expensive jobs may set this to true */
  45         protected $removeDuplicates;
  46
  47         /** @var string Text for error that occurred last */
  48         protected $error;
  49
  50         /**
  51          * Run the job
  52          * @return bool Success
  53          */
  54         abstract public function run();
  55
  56         /**
  57          * Create the appropriate object to handle a specific job
  58          *
  59          * @param string $command Job command
  60          * @param Title $title Associated title
  61          * @param array $params Job parameters
  62          * @throws MWException
  63          * @return Job
  64          */
  65         public static function factory( $command, Title $title, $params = [] ) {
  66                 global $wgJobClasses;
  67
  68                 if ( isset( $wgJobClasses[$command] ) ) {
  69                         $class = $wgJobClasses[$command];
  70
  71                         $job = new $class( $title, $params );
  72                         $job->command = $command;
  73
  74                         return $job;
  75                 }
  76
  77                 throw new InvalidArgumentException( "Invalid job command '{$command}'" );
  78         }
  79
  80         /**
  81          * @param string $command
  82          * @param Title $title
  83          * @param array|bool $params Can not be === true
  84          */
  85         public function __construct( $command, $title, $params = false ) {
  86                 $this->command = $command;
  87                 $this->title = $title;
  88                 $this->params = is_array( $params ) ? $params : []; // sanity
  89
  90                 // expensive jobs may set this to true
  91                 $this->removeDuplicates = false;
  92         }
  93
  94         /**
  95          * Batch-insert a group of jobs into the queue.
  96          * This will be wrapped in a transaction with a forced commit.
  97          *
  98          * This may add duplicate at insert time, but they will be
  99          * removed later on, when the first one is popped.
 100          *
 101          * @param Job[] $jobs Array of Job objects
 102          * @return bool
 103          * @deprecated since 1.21
 104          */
 105         public static function batchInsert( $jobs ) {
 106                 wfDeprecated( __METHOD__, '1.21' );
 107                 JobQueueGroup::singleton()->push( $jobs );
 108                 return true;
 109         }
 110
 111         /**
 112          * @return string
 113          */
 114         public function getType() {
 115                 return $this->command;
 116         }
 117
 118         /**
 119          * @return Title
 120          */
 121         public function getTitle() {
 122                 return $this->title;
 123         }
 124
 125         /**
 126          * @return array
 127          */
 128         public function getParams() {
 129                 return $this->params;
 130         }
 131
 132         /**
 133          * @return int|null UNIX timestamp to delay running this job until, otherwise null
 134          * @since 1.22
 135          */
 136         public function getReleaseTimestamp() {
 137                 return isset( $this->params['jobReleaseTimestamp'] )
 138                         ? wfTimestampOrNull( TS_UNIX, $this->params['jobReleaseTimestamp'] )
 139                         : null;
 140         }
 141
 142         /**
 143          * @return int|null UNIX timestamp of when the job was queued, or null
 144          * @since 1.26
 145          */
 146         public function getQueuedTimestamp() {
 147                 return isset( $this->metadata['timestamp'] )
 148                         ? wfTimestampOrNull( TS_UNIX, $this->metadata['timestamp'] )
 149                         : null;
 150         }
 151
 152         /**
 153          * @return int|null UNIX timestamp of when the job was runnable, or null
 154          * @since 1.26
 155          */
 156         public function getReadyTimestamp() {
 157                 return $this->getReleaseTimestamp() ?: $this->getQueuedTimestamp();
 158         }
 159
 160         /**
 161          * Whether the queue should reject insertion of this job if a duplicate exists
 162          *
 163          * This can be used to avoid duplicated effort or combined with delayed jobs to
 164          * coalesce updates into larger batches. Claimed jobs are never treated as
 165          * duplicates of new jobs, and some queues may allow a few duplicates due to
 166          * network partitions and fail-over. Thus, additional locking is needed to
 167          * enforce mutual exclusion if this is really needed.
 168          *
 169          * @return bool
 170          */
 171         public function ignoreDuplicates() {
 172                 return $this->removeDuplicates;
 173         }
 174
 175         /**
 176          * @return bool Whether this job can be retried on failure by job runners
 177          * @since 1.21
 178          */
 179         public function allowRetries() {
 180                 return true;
 181         }
 182
 183         /**
 184          * @return int Number of actually "work items" handled in this job
 185          * @see $wgJobBackoffThrottling
 186          * @since 1.23
 187          */
 188         public function workItemCount() {
 189                 return 1;
 190         }
 191
 192         /**
 193          * Subclasses may need to override this to make duplication detection work.
 194          * The resulting map conveys everything that makes the job unique. This is
 195          * only checked if ignoreDuplicates() returns true, meaning that duplicate
 196          * jobs are supposed to be ignored.
 197          *
 198          * @return array Map of key/values
 199          * @since 1.21
 200          */
 201         public function getDeduplicationInfo() {
 202                 $info = [
 203                         'type' => $this->getType(),
 204                         'namespace' => $this->getTitle()->getNamespace(),
 205                         'title' => $this->getTitle()->getDBkey(),
 206                         'params' => $this->getParams()
 207                 ];
 208                 if ( is_array( $info['params'] ) ) {
 209                         // Identical jobs with different "root" jobs should count as duplicates
 210                         unset( $info['params']['rootJobSignature'] );
 211                         unset( $info['params']['rootJobTimestamp'] );
 212                         // Likewise for jobs with different delay times
 213                         unset( $info['params']['jobReleaseTimestamp'] );
 214                         // Queues pack and hash this array, so normalize the order
 215                         ksort( $info['params'] );
 216                 }
 217
 218                 return $info;
 219         }
 220
 221         /**
 222          * Get "root job" parameters for a task
 223          *
 224          * This is used to no-op redundant jobs, including child jobs of jobs,
 225          * as long as the children inherit the root job parameters. When a job
 226          * with root job parameters and "rootJobIsSelf" set is pushed, the
 227          * deduplicateRootJob() method is automatically called on it. If the
 228          * root job is only virtual and not actually pushed (e.g. the sub-jobs
 229          * are inserted directly), then call deduplicateRootJob() directly.
 230          *
 231          * @see JobQueue::deduplicateRootJob()
 232          *
 233          * @param string $key A key that identifies the task
 234          * @return array Map of:
 235          *   - rootJobIsSelf    : true
 236          *   - rootJobSignature : hash (e.g. SHA1) that identifies the task
 237          *   - rootJobTimestamp : TS_MW timestamp of this instance of the task
 238          * @since 1.21
 239          */
 240         public static function newRootJobParams( $key ) {
 241                 return [
 242                         'rootJobIsSelf'    => true,
 243                         'rootJobSignature' => sha1( $key ),
 244                         'rootJobTimestamp' => wfTimestampNow()
 245                 ];
 246         }
 247
 248         /**
 249          * @see JobQueue::deduplicateRootJob()
 250          * @return array
 251          * @since 1.21
 252          */
 253         public function getRootJobParams() {
 254                 return [
 255                         'rootJobSignature' => isset( $this->params['rootJobSignature'] )
 256                                 ? $this->params['rootJobSignature']
 257                                 : null,
 258                         'rootJobTimestamp' => isset( $this->params['rootJobTimestamp'] )
 259                                 ? $this->params['rootJobTimestamp']
 260                                 : null
 261                 ];
 262         }
 263
 264         /**
 265          * @see JobQueue::deduplicateRootJob()
 266          * @return bool
 267          * @since 1.22
 268          */
 269         public function hasRootJobParams() {
 270                 return isset( $this->params['rootJobSignature'] )
 271                         && isset( $this->params['rootJobTimestamp'] );
 272         }
 273
 274         /**
 275          * @see JobQueue::deduplicateRootJob()
 276          * @return bool Whether this is job is a root job
 277          */
 278         public function isRootJob() {
 279                 return $this->hasRootJobParams() && !empty( $this->params['rootJobIsSelf'] );
 280         }
 281
 282         /**
 283          * Insert a single job into the queue.
 284          * @return bool True on success
 285          * @deprecated since 1.21
 286          */
 287         public function insert() {
 288                 JobQueueGroup::singleton()->push( $this );
 289                 return true;
 290         }
 291
 292         /**
 293          * @return string
 294          */
 295         public function toString() {
 296                 $truncFunc = function ( $value ) {
 297                         $value = (string)$value;
 298                         if ( mb_strlen( $value ) > 1024 ) {
 299                                 $value = "string(" . mb_strlen( $value ) . ")";
 300                         }
 301                         return $value;
 302                 };
 303
 304                 $paramString = '';
 305                 if ( $this->params ) {
 306                         foreach ( $this->params as $key => $value ) {
 307                                 if ( $paramString != '' ) {
 308                                         $paramString .= ' ';
 309                                 }
 310                                 if ( is_array( $value ) ) {
 311                                         $filteredValue = [];
 312                                         foreach ( $value as $k => $v ) {
 313                                                 if ( is_scalar( $v ) ) {
 314                                                         $filteredValue[$k] = $truncFunc( $v );
 315                                                 } else {
 316                                                         $filteredValue = null;
 317                                                         break;
 318                                                 }
 319                                         }
 320                                         if ( $filteredValue && count( $filteredValue ) < 10 ) {
 321                                                 $value = FormatJson::encode( $filteredValue );
 322                                         } else {
 323                                                 $value = "array(" . count( $value ) . ")";
 324                                         }
 325                                 } elseif ( is_object( $value ) && !method_exists( $value, '__toString' ) ) {
 326                                         $value = "object(" . get_class( $value ) . ")";
 327                                 }
 328
 329                                 $paramString .= "$key={$truncFunc( $value )}";
 330                         }
 331                 }
 332
 333                 $metaString = '';
 334                 foreach ( $this->metadata as $key => $value ) {
 335                         if ( is_scalar( $value ) && mb_strlen( $value ) < 1024 ) {
 336                                 $metaString .= ( $metaString ? ",$key=$value" : "$key=$value" );
 337                         }
 338                 }
 339
 340                 $s = $this->command;
 341                 if ( is_object( $this->title ) ) {
 342                         $s .= " {$this->title->getPrefixedDBkey()}";
 343                 }
 344                 if ( $paramString != '' ) {
 345                         $s .= " $paramString";
 346                 }
 347                 if ( $metaString != '' ) {
 348                         $s .= " ($metaString)";
 349                 }
 350
 351                 return $s;
 352         }
 353
 354         protected function setLastError( $error ) {
 355                 $this->error = $error;
 356         }
 357
 358         public function getLastError() {
 359                 return $this->error;
 360         }
 361 }