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          * Whether the queue should reject insertion of this job if a duplicate exists
 149          *
 150          * This can be used to avoid duplicated effort or combined with delayed jobs to
 151          * coalesce updates into larger batches. Claimed jobs are never treated as
 152          * duplicates of new jobs, and some queues may allow a few duplicates due to
 153          * network partitions and fail-over. Thus, additional locking is needed to
 154          * enforce mutual exclusion if this is really needed.
 155          *
 156          * @return bool
 157          */
 158         public function ignoreDuplicates() {
 159                 return $this->removeDuplicates;
 160         }
 161
 162         /**
 163          * @return bool Whether this job can be retried on failure by job runners
 164          * @since 1.21
 165          */
 166         public function allowRetries() {
 167                 return true;
 168         }
 169
 170         /**
 171          * @return int Number of actually "work items" handled in this job
 172          * @see $wgJobBackoffThrottling
 173          * @since 1.23
 174          */
 175         public function workItemCount() {
 176                 return 1;
 177         }
 178
 179         /**
 180          * Subclasses may need to override this to make duplication detection work.
 181          * The resulting map conveys everything that makes the job unique. This is
 182          * only checked if ignoreDuplicates() returns true, meaning that duplicate
 183          * jobs are supposed to be ignored.
 184          *
 185          * @return array Map of key/values
 186          * @since 1.21
 187          */
 188         public function getDeduplicationInfo() {
 189                 $info = array(
 190                         'type' => $this->getType(),
 191                         'namespace' => $this->getTitle()->getNamespace(),
 192                         'title' => $this->getTitle()->getDBkey(),
 193                         'params' => $this->getParams()
 194                 );
 195                 if ( is_array( $info['params'] ) ) {
 196                         // Identical jobs with different "root" jobs should count as duplicates
 197                         unset( $info['params']['rootJobSignature'] );
 198                         unset( $info['params']['rootJobTimestamp'] );
 199                         // Likewise for jobs with different delay times
 200                         unset( $info['params']['jobReleaseTimestamp'] );
 201                         // Queues pack and hash this array, so normalize the order
 202                         ksort( $info['params'] );
 203                 }
 204
 205                 return $info;
 206         }
 207
 208         /**
 209          * Get "root job" parameters for a task
 210          *
 211          * This is used to no-op redundant jobs, including child jobs of jobs,
 212          * as long as the children inherit the root job parameters. When a job
 213          * with root job parameters and "rootJobIsSelf" set is pushed, the
 214          * deduplicateRootJob() method is automatically called on it. If the
 215          * root job is only virtual and not actually pushed (e.g. the sub-jobs
 216          * are inserted directly), then call deduplicateRootJob() directly.
 217          *
 218          * @see JobQueue::deduplicateRootJob()
 219          *
 220          * @param string $key A key that identifies the task
 221          * @return array Map of:
 222          *   - rootJobIsSelf    : true
 223          *   - rootJobSignature : hash (e.g. SHA1) that identifies the task
 224          *   - rootJobTimestamp : TS_MW timestamp of this instance of the task
 225          * @since 1.21
 226          */
 227         public static function newRootJobParams( $key ) {
 228                 return array(
 229                         'rootJobIsSelf'    => true,
 230                         'rootJobSignature' => sha1( $key ),
 231                         'rootJobTimestamp' => wfTimestampNow()
 232                 );
 233         }
 234
 235         /**
 236          * @see JobQueue::deduplicateRootJob()
 237          * @return array
 238          * @since 1.21
 239          */
 240         public function getRootJobParams() {
 241                 return array(
 242                         'rootJobSignature' => isset( $this->params['rootJobSignature'] )
 243                                 ? $this->params['rootJobSignature']
 244                                 : null,
 245                         'rootJobTimestamp' => isset( $this->params['rootJobTimestamp'] )
 246                                 ? $this->params['rootJobTimestamp']
 247                                 : null
 248                 );
 249         }
 250
 251         /**
 252          * @see JobQueue::deduplicateRootJob()
 253          * @return bool
 254          * @since 1.22
 255          */
 256         public function hasRootJobParams() {
 257                 return isset( $this->params['rootJobSignature'] )
 258                         && isset( $this->params['rootJobTimestamp'] );
 259         }
 260
 261         /**
 262          * @see JobQueue::deduplicateRootJob()
 263          * @return bool Whether this is job is a root job
 264          */
 265         public function isRootJob() {
 266                 return $this->hasRootJobParams() && !empty( $this->params['rootJobIsSelf'] );
 267         }
 268
 269         /**
 270          * Insert a single job into the queue.
 271          * @return bool True on success
 272          * @deprecated since 1.21
 273          */
 274         public function insert() {
 275                 JobQueueGroup::singleton()->push( $this );
 276                 return true;
 277         }
 278
 279         /**
 280          * @return string
 281          */
 282         public function toString() {
 283                 $truncFunc = function ( $value ) {
 284                         $value = (string)$value;
 285                         if ( mb_strlen( $value ) > 1024 ) {
 286                                 $value = "string(" . mb_strlen( $value ) . ")";
 287                         }
 288                         return $value;
 289                 };
 290
 291                 $paramString = '';
 292                 if ( $this->params ) {
 293                         foreach ( $this->params as $key => $value ) {
 294                                 if ( $paramString != '' ) {
 295                                         $paramString .= ' ';
 296                                 }
 297                                 if ( is_array( $value ) ) {
 298                                         $filteredValue = array();
 299                                         foreach ( $value as $k => $v ) {
 300                                                 if ( is_scalar( $v ) ) {
 301                                                         $filteredValue[$k] = $truncFunc( $v );
 302                                                 } else {
 303                                                         $filteredValue = null;
 304                                                         break;
 305                                                 }
 306                                         }
 307                                         if ( $filteredValue && count( $filteredValue ) < 10 ) {
 308                                                 $value = FormatJson::encode( $filteredValue );
 309                                         } else {
 310                                                 $value = "array(" . count( $value ) . ")";
 311                                         }
 312                                 } elseif ( is_object( $value ) && !method_exists( $value, '__toString' ) ) {
 313                                         $value = "object(" . get_class( $value ) . ")";
 314                                 }
 315
 316                                 $paramString .= "$key={$truncFunc( $value )}";
 317                         }
 318                 }
 319
 320                 $metaString = '';
 321                 foreach ( $this->metadata as $key => $value ) {
 322                         if ( is_scalar( $value ) && mb_strlen( $value ) < 1024 ) {
 323                                 $metaString .= ( $metaString ? ",$key=$value" : "$key=$value" );
 324                         }
 325                 }
 326
 327                 $s = $this->command;
 328                 if ( is_object( $this->title ) ) {
 329                         $s .= " {$this->title->getPrefixedDBkey()}";
 330                 }
 331                 if ( $paramString != '' ) {
 332                         $s .= " $paramString";
 333                 }
 334                 if ( $metaString != '' ) {
 335                         $s .= " ($metaString)";
 336                 }
 337
 338                 return $s;
 339         }
 340
 341         protected function setLastError( $error ) {
 342                 $this->error = $error;
 343         }
 344
 345         public function getLastError() {
 346                 return $this->error;
 347         }
 348 }