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