includes/job/Job.php

   1 <?php
   2 /**
   3  * Job queue 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  *
  28  * @ingroup JobQueue
  29  */
  30 abstract class Job {
  31         /**
  32          * @var Title
  33          */
  34         var $title;
  35
  36         var $command,
  37                 $params,
  38                 $id,
  39                 $removeDuplicates,
  40                 $error;
  41
  42         /** @var Array Additional queue metadata */
  43         public $metadata = array();
  44
  45         /*-------------------------------------------------------------------------
  46          * Abstract functions
  47          *------------------------------------------------------------------------*/
  48
  49         /**
  50          * Run the job
  51          * @return boolean success
  52          */
  53         abstract public function run();
  54
  55         /*-------------------------------------------------------------------------
  56          * Static functions
  57          *------------------------------------------------------------------------*/
  58
  59         /**
  60          * Create the appropriate object to handle a specific job
  61          *
  62          * @param string $command Job command
  63          * @param $title Title: Associated title
  64          * @param array|bool $params Job parameters
  65          * @param int $id Job identifier
  66          * @throws MWException
  67          * @return Job
  68          */
  69         public static function factory( $command, Title $title, $params = false, $id = 0 ) {
  70                 global $wgJobClasses;
  71                 if ( isset( $wgJobClasses[$command] ) ) {
  72                         $class = $wgJobClasses[$command];
  73
  74                         return new $class( $title, $params, $id );
  75                 }
  76                 throw new MWException( "Invalid job command `{$command}`" );
  77         }
  78
  79         /**
  80          * Batch-insert a group of jobs into the queue.
  81          * This will be wrapped in a transaction with a forced commit.
  82          *
  83          * This may add duplicate at insert time, but they will be
  84          * removed later on, when the first one is popped.
  85          *
  86          * @param array $jobs of Job objects
  87          * @return bool
  88          * @deprecated since 1.21
  89          */
  90         public static function batchInsert( $jobs ) {
  91                 return JobQueueGroup::singleton()->push( $jobs );
  92         }
  93
  94         /**
  95          * Insert a group of jobs into the queue.
  96          *
  97          * Same as batchInsert() but does not commit and can thus
  98          * be rolled-back as part of a larger transaction. However,
  99          * large batches of jobs can cause slave lag.
 100          *
 101          * @param array $jobs of Job objects
 102          * @return bool
 103          * @deprecated since 1.21
 104          */
 105         public static function safeBatchInsert( $jobs ) {
 106                 return JobQueueGroup::singleton()->push( $jobs, JobQueue::QOS_ATOMIC );
 107         }
 108
 109         /**
 110          * Pop a job of a certain type.  This tries less hard than pop() to
 111          * actually find a job; it may be adversely affected by concurrent job
 112          * runners.
 113          *
 114          * @param $type string
 115          * @return Job|bool Returns false if there are no jobs
 116          * @deprecated since 1.21
 117          */
 118         public static function pop_type( $type ) {
 119                 return JobQueueGroup::singleton()->get( $type )->pop();
 120         }
 121
 122         /**
 123          * Pop a job off the front of the queue.
 124          * This is subject to $wgJobTypesExcludedFromDefaultQueue.
 125          *
 126          * @return Job or false if there's no jobs
 127          * @deprecated since 1.21
 128          */
 129         public static function pop() {
 130                 return JobQueueGroup::singleton()->pop();
 131         }
 132
 133         /*-------------------------------------------------------------------------
 134          * Non-static functions
 135          *------------------------------------------------------------------------*/
 136
 137         /**
 138          * @param $command
 139          * @param $title
 140          * @param $params array|bool
 141          * @param $id int
 142          */
 143         public function __construct( $command, $title, $params = false, $id = 0 ) {
 144                 $this->command = $command;
 145                 $this->title = $title;
 146                 $this->params = $params;
 147                 $this->id = $id;
 148
 149                 $this->removeDuplicates = false; // expensive jobs may set this to true
 150         }
 151
 152         /**
 153          * @return integer May be 0 for jobs stored outside the DB
 154          * @deprecated since 1.22
 155          */
 156         public function getId() {
 157                 return $this->id;
 158         }
 159
 160         /**
 161          * @return string
 162          */
 163         public function getType() {
 164                 return $this->command;
 165         }
 166
 167         /**
 168          * @return Title
 169          */
 170         public function getTitle() {
 171                 return $this->title;
 172         }
 173
 174         /**
 175          * @return array
 176          */
 177         public function getParams() {
 178                 return $this->params;
 179         }
 180
 181         /**
 182          * @return integer|null UNIX timestamp to delay running this job until, otherwise null
 183          * @since 1.22
 184          */
 185         public function getReleaseTimestamp() {
 186                 return isset( $this->params['jobReleaseTimestamp'] )
 187                         ? wfTimestampOrNull( TS_UNIX, $this->params['jobReleaseTimestamp'] )
 188                         : null;
 189         }
 190
 191         /**
 192          * @return bool Whether only one of each identical set of jobs should be run
 193          */
 194         public function ignoreDuplicates() {
 195                 return $this->removeDuplicates;
 196         }
 197
 198         /**
 199          * @return bool Whether this job can be retried on failure by job runners
 200          * @since 1.21
 201          */
 202         public function allowRetries() {
 203                 return true;
 204         }
 205
 206         /**
 207          * Subclasses may need to override this to make duplication detection work.
 208          * The resulting map conveys everything that makes the job unique. This is
 209          * only checked if ignoreDuplicates() returns true, meaning that duplicate
 210          * jobs are supposed to be ignored.
 211          *
 212          * @return Array Map of key/values
 213          * @since 1.21
 214          */
 215         public function getDeduplicationInfo() {
 216                 $info = array(
 217                         'type' => $this->getType(),
 218                         'namespace' => $this->getTitle()->getNamespace(),
 219                         'title' => $this->getTitle()->getDBkey(),
 220                         'params' => $this->getParams()
 221                 );
 222                 if ( is_array( $info['params'] ) ) {
 223                         // Identical jobs with different "root" jobs should count as duplicates
 224                         unset( $info['params']['rootJobSignature'] );
 225                         unset( $info['params']['rootJobTimestamp'] );
 226                         // Likewise for jobs with different delay times
 227                         unset( $info['params']['jobReleaseTimestamp'] );
 228                 }
 229
 230                 return $info;
 231         }
 232
 233         /**
 234          * @see JobQueue::deduplicateRootJob()
 235          * @param string $key A key that identifies the task
 236          * @return Array
 237          * @since 1.21
 238          */
 239         public static function newRootJobParams( $key ) {
 240                 return array(
 241                         'rootJobSignature' => sha1( $key ),
 242                         'rootJobTimestamp' => wfTimestampNow()
 243                 );
 244         }
 245
 246         /**
 247          * @see JobQueue::deduplicateRootJob()
 248          * @return Array
 249          * @since 1.21
 250          */
 251         public function getRootJobParams() {
 252                 return array(
 253                         'rootJobSignature' => isset( $this->params['rootJobSignature'] )
 254                                 ? $this->params['rootJobSignature']
 255                                 : null,
 256                         'rootJobTimestamp' => isset( $this->params['rootJobTimestamp'] )
 257                                 ? $this->params['rootJobTimestamp']
 258                                 : null
 259                 );
 260         }
 261
 262         /**
 263          * @see JobQueue::deduplicateRootJob()
 264          * @return bool
 265          * @since 1.22
 266          */
 267         public function hasRootJobParams() {
 268                 return isset( $this->params['rootJobSignature'] )
 269                         && isset( $this->params['rootJobTimestamp'] );
 270         }
 271
 272         /**
 273          * Insert a single job into the queue.
 274          * @return bool true on success
 275          * @deprecated since 1.21
 276          */
 277         public function insert() {
 278                 return JobQueueGroup::singleton()->push( $this );
 279         }
 280
 281         /**
 282          * @return string
 283          */
 284         public function toString() {
 285                 $paramString = '';
 286                 if ( $this->params ) {
 287                         foreach ( $this->params as $key => $value ) {
 288                                 if ( $paramString != '' ) {
 289                                         $paramString .= ' ';
 290                                 }
 291                                 if ( is_array( $value ) ) {
 292                                         $value = "array(" . count( $value ) . ")";
 293                                 } elseif ( is_object( $value ) && !method_exists( $value, '__toString' ) ) {
 294                                         $value = "object(" . get_class( $value ) . ")";
 295                                 }
 296                                 $value = (string)$value;
 297                                 if ( mb_strlen( $value ) > 1024 ) {
 298                                         $value = "string(" . mb_strlen( $value ) . ")";
 299                                 }
 300
 301                                 $paramString .= "$key=$value";
 302                         }
 303                 }
 304
 305                 if ( is_object( $this->title ) ) {
 306                         $s = "{$this->command} " . $this->title->getPrefixedDBkey();
 307                         if ( $paramString !== '' ) {
 308                                 $s .= ' ' . $paramString;
 309                         }
 310
 311                         return $s;
 312                 } else {
 313                         return "{$this->command} $paramString";
 314                 }
 315         }
 316
 317         protected function setLastError( $error ) {
 318                 $this->error = $error;
 319         }
 320
 321         public function getLastError() {
 322                 return $this->error;
 323         }
 324 }