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 $command String: Job command
  63          * @param $title Title: Associated title
  64          * @param $params Array|bool: Job parameters
  65          * @param $id Int: 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                         return new $class( $title, $params, $id );
  74                 }
  75                 throw new MWException( "Invalid job command `{$command}`" );
  76         }
  77
  78         /**
  79          * Batch-insert a group of jobs into the queue.
  80          * This will be wrapped in a transaction with a forced commit.
  81          *
  82          * This may add duplicate at insert time, but they will be
  83          * removed later on, when the first one is popped.
  84          *
  85          * @param $jobs array of Job objects
  86          * @deprecated 1.21
  87          */
  88         public static function batchInsert( $jobs ) {
  89                 return JobQueueGroup::singleton()->push( $jobs );
  90         }
  91
  92         /**
  93          * Insert a group of jobs into the queue.
  94          *
  95          * Same as batchInsert() but does not commit and can thus
  96          * be rolled-back as part of a larger transaction. However,
  97          * large batches of jobs can cause slave lag.
  98          *
  99          * @param $jobs array of Job objects
 100          * @deprecated 1.21
 101          */
 102         public static function safeBatchInsert( $jobs ) {
 103                 return JobQueueGroup::singleton()->push( $jobs, JobQueue::QoS_Atomic );
 104         }
 105
 106         /**
 107          * Pop a job of a certain type.  This tries less hard than pop() to
 108          * actually find a job; it may be adversely affected by concurrent job
 109          * runners.
 110          *
 111          * @param $type string
 112          * @return Job
 113          * @deprecated 1.21
 114          */
 115         public static function pop_type( $type ) {
 116                 return JobQueueGroup::singleton()->get( $type )->pop();
 117         }
 118
 119         /**
 120          * Pop a job off the front of the queue.
 121          * This is subject to $wgJobTypesExcludedFromDefaultQueue.
 122          *
 123          * @return Job or false if there's no jobs
 124          * @deprecated 1.21
 125          */
 126         public static function pop() {
 127                 return JobQueueGroup::singleton()->pop();
 128         }
 129
 130         /*-------------------------------------------------------------------------
 131          * Non-static functions
 132          *------------------------------------------------------------------------*/
 133
 134         /**
 135          * @param $command
 136          * @param $title
 137          * @param $params array|bool
 138          * @param $id int
 139          */
 140         public function __construct( $command, $title, $params = false, $id = 0 ) {
 141                 $this->command = $command;
 142                 $this->title = $title;
 143                 $this->params = $params;
 144                 $this->id = $id;
 145
 146                 $this->removeDuplicates = false; // expensive jobs may set this to true
 147         }
 148
 149         /**
 150          * @return integer May be 0 for jobs stored outside the DB
 151          */
 152         public function getId() {
 153                 return $this->id;
 154         }
 155
 156         /**
 157          * @return string
 158          */
 159         public function getType() {
 160                 return $this->command;
 161         }
 162
 163         /**
 164          * @return Title
 165          */
 166         public function getTitle() {
 167                 return $this->title;
 168         }
 169
 170         /**
 171          * @return array
 172          */
 173         public function getParams() {
 174                 return $this->params;
 175         }
 176
 177         /**
 178          * @return bool
 179          */
 180         public function ignoreDuplicates() {
 181                 return $this->removeDuplicates;
 182         }
 183
 184         /**
 185          * Subclasses may need to override this to make duplication detection work
 186          *
 187          * @return Array Map of key/values
 188          */
 189         public function getDeduplicationInfo() {
 190                 $info = array(
 191                         'type'      => $this->getType(),
 192                         'namespace' => $this->getTitle()->getNamespace(),
 193                         'title'     => $this->getTitle()->getDBkey(),
 194                         'params'    => $this->getParams()
 195                 );
 196                 // Identical jobs with different "root" jobs should count as duplicates
 197                 if ( is_array( $info['params'] ) ) {
 198                         unset( $info['params']['rootJobSignature'] );
 199                         unset( $info['params']['rootJobTimestamp'] );
 200                 }
 201                 return $info;
 202         }
 203
 204         /**
 205          * @param $key string A key that identifies the task
 206          * @return Array
 207          */
 208         public static function newRootJobParams( $key ) {
 209                 return array(
 210                         'rootJobSignature' => sha1( $key ),
 211                         'rootJobTimestamp' => wfTimestampNow()
 212                 );
 213         }
 214
 215         /**
 216          * @return Array
 217          */
 218         public function getRootJobParams() {
 219                 return array(
 220                         'rootJobSignature' => isset( $this->params['rootJobSignature'] )
 221                                 ? $this->params['rootJobSignature']
 222                                 : null,
 223                         'rootJobTimestamp' => isset( $this->params['rootJobTimestamp'] )
 224                                 ? $this->params['rootJobTimestamp']
 225                                 : null
 226                 );
 227         }
 228
 229         /**
 230          * Insert a single job into the queue.
 231          * @return bool true on success
 232          * @deprecated 1.21
 233          */
 234         public function insert() {
 235                 return JobQueueGroup::singleton()->push( $this );
 236         }
 237
 238         /**
 239          * @return string
 240          */
 241         public function toString() {
 242                 $paramString = '';
 243                 if ( $this->params ) {
 244                         foreach ( $this->params as $key => $value ) {
 245                                 if ( $paramString != '' ) {
 246                                         $paramString .= ' ';
 247                                 }
 248
 249                                 if ( is_array( $value ) ) {
 250                                         $value = "array(" . count( $value ) . ")";
 251                                 } else if ( is_object( $value ) && !method_exists( $value, '__toString' ) ) {
 252                                         $value = "object(" . get_class( $value ) . ")";
 253                                 }
 254
 255                                 $paramString .= "$key=$value";
 256                         }
 257                 }
 258
 259                 if ( is_object( $this->title ) ) {
 260                         $s = "{$this->command} " . $this->title->getPrefixedDBkey();
 261                         if ( $paramString !== '' ) {
 262                                 $s .= ' ' . $paramString;
 263                         }
 264                         return $s;
 265                 } else {
 266                         return "{$this->command} $paramString";
 267                 }
 268         }
 269
 270         protected function setLastError( $error ) {
 271                 $this->error = $error;
 272         }
 273
 274         public function getLastError() {
 275                 return $this->error;
 276         }
 277 }