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         /*-------------------------------------------------------------------------
  43          * Abstract functions
  44          *------------------------------------------------------------------------*/
  45
  46         /**
  47          * Run the job
  48          * @return boolean success
  49          */
  50         abstract public function run();
  51
  52         /*-------------------------------------------------------------------------
  53          * Static functions
  54          *------------------------------------------------------------------------*/
  55
  56         /**
  57          * Create the appropriate object to handle a specific job
  58          *
  59          * @param $command String: Job command
  60          * @param $title Title: Associated title
  61          * @param $params Array|bool: Job parameters
  62          * @param $id Int: Job identifier
  63          * @throws MWException
  64          * @return Job
  65          */
  66         public static function factory( $command, Title $title, $params = false, $id = 0 ) {
  67                 global $wgJobClasses;
  68                 if( isset( $wgJobClasses[$command] ) ) {
  69                         $class = $wgJobClasses[$command];
  70                         return new $class( $title, $params, $id );
  71                 }
  72                 throw new MWException( "Invalid job command `{$command}`" );
  73         }
  74
  75         /**
  76          * Batch-insert a group of jobs into the queue.
  77          * This will be wrapped in a transaction with a forced commit.
  78          *
  79          * This may add duplicate at insert time, but they will be
  80          * removed later on, when the first one is popped.
  81          *
  82          * @param $jobs array of Job objects
  83          * @deprecated 1.21
  84          */
  85         public static function batchInsert( $jobs ) {
  86                 return JobQueueGroup::singleton()->push( $jobs );
  87         }
  88
  89         /**
  90          * Insert a group of jobs into the queue.
  91          *
  92          * Same as batchInsert() but does not commit and can thus
  93          * be rolled-back as part of a larger transaction. However,
  94          * large batches of jobs can cause slave lag.
  95          *
  96          * @param $jobs array of Job objects
  97          * @deprecated 1.21
  98          */
  99         public static function safeBatchInsert( $jobs ) {
 100                 return JobQueueGroup::singleton()->push( $jobs, JobQueue::QoS_Atomic );
 101         }
 102
 103         /**
 104          * Pop a job of a certain type.  This tries less hard than pop() to
 105          * actually find a job; it may be adversely affected by concurrent job
 106          * runners.
 107          *
 108          * @param $type string
 109          * @return Job
 110          * @deprecated 1.21
 111          */
 112         public static function pop_type( $type ) {
 113                 return JobQueueGroup::singleton()->get( $type )->pop();
 114         }
 115
 116         /**
 117          * Pop a job off the front of the queue.
 118          * This is subject to $wgJobTypesExcludedFromDefaultQueue.
 119          *
 120          * @return Job or false if there's no jobs
 121          * @deprecated 1.21
 122          */
 123         public static function pop() {
 124                 return JobQueueGroup::singleton()->pop();
 125         }
 126
 127         /*-------------------------------------------------------------------------
 128          * Non-static functions
 129          *------------------------------------------------------------------------*/
 130
 131         /**
 132          * @param $command
 133          * @param $title
 134          * @param $params array|bool
 135          * @param $id int
 136          */
 137         public function __construct( $command, $title, $params = false, $id = 0 ) {
 138                 $this->command = $command;
 139                 $this->title = $title;
 140                 $this->params = $params;
 141                 $this->id = $id;
 142
 143                 $this->removeDuplicates = false; // expensive jobs may set this to true
 144         }
 145
 146         /**
 147          * @return integer May be 0 for jobs stored outside the DB
 148          */
 149         public function getId() {
 150                 return $this->id;
 151         }
 152
 153         /**
 154          * @return string
 155          */
 156         public function getType() {
 157                 return $this->command;
 158         }
 159
 160         /**
 161          * @return Title
 162          */
 163         public function getTitle() {
 164                 return $this->title;
 165         }
 166
 167         /**
 168          * @return array
 169          */
 170         public function getParams() {
 171                 return $this->params;
 172         }
 173
 174         /**
 175          * @return bool
 176          */
 177         public function ignoreDuplicates() {
 178                 return $this->removeDuplicates;
 179         }
 180
 181         /**
 182          * Subclasses may need to override this to make duplication detection work
 183          *
 184          * @return Array Map of key/values
 185          */
 186         public function getDeduplicationInfo() {
 187                 $info = array(
 188                         'type'      => $this->getType(),
 189                         'namespace' => $this->getTitle()->getNamespace(),
 190                         'title'     => $this->getTitle()->getDBkey(),
 191                         'params'    => $this->getParams()
 192                 );
 193                 // Identical jobs with different "root" jobs should count as duplicates
 194                 if ( is_array( $info['params'] ) ) {
 195                         unset( $info['params']['rootJobSignature'] );
 196                         unset( $info['params']['rootJobTimestamp'] );
 197                 }
 198                 return $info;
 199         }
 200
 201         /**
 202          * @param $key string A key that identifies the task
 203          * @return Array
 204          */
 205         public static function newRootJobParams( $key ) {
 206                 return array(
 207                         'rootJobSignature' => sha1( $key ),
 208                         'rootJobTimestamp' => wfTimestampNow()
 209                 );
 210         }
 211
 212         /**
 213          * @return Array
 214          */
 215         public function getRootJobParams() {
 216                 return array(
 217                         'rootJobSignature' => isset( $this->params['rootJobSignature'] )
 218                                 ? $this->params['rootJobSignature']
 219                                 : null,
 220                         'rootJobTimestamp' => isset( $this->params['rootJobTimestamp'] )
 221                                 ? $this->params['rootJobTimestamp']
 222                                 : null
 223                 );
 224         }
 225
 226         /**
 227          * Insert a single job into the queue.
 228          * @return bool true on success
 229          * @deprecated 1.21
 230          */
 231         public function insert() {
 232                 return JobQueueGroup::singleton()->push( $this );
 233         }
 234
 235         /**
 236          * @return string
 237          */
 238         public function toString() {
 239                 $paramString = '';
 240                 if ( $this->params ) {
 241                         foreach ( $this->params as $key => $value ) {
 242                                 if ( $paramString != '' ) {
 243                                         $paramString .= ' ';
 244                                 }
 245                                 $paramString .= "$key=$value";
 246                         }
 247                 }
 248
 249                 if ( is_object( $this->title ) ) {
 250                         $s = "{$this->command} " . $this->title->getPrefixedDBkey();
 251                         if ( $paramString !== '' ) {
 252                                 $s .= ' ' . $paramString;
 253                         }
 254                         return $s;
 255                 } else {
 256                         return "{$this->command} $paramString";
 257                 }
 258         }
 259
 260         protected function setLastError( $error ) {
 261                 $this->error = $error;
 262         }
 263
 264         public function getLastError() {
 265                 return $this->error;
 266         }
 267 }