includes/jobqueue/RunnableJob.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @file
  19  */
  20
  21 /**
  22  * Job that has a run() method and metadata accessors for JobQueue::pop() and JobQueue::ack().
  23  *
  24  * Instances are not only enqueueable via JobQueue::push(), but they can also be executed by
  25  * calling their run() method. When constructing a job to be enqueued via JobQueue::push(), it
  26  * will not be possible to construct a RunnableJob instance if the class for that job is not
  27  * loaded by the application for the local DB domain. In that case, the general-purpose
  28  * JobSpecification class can be used instead.
  29  *
  30  * See [the architecture doc](@ref jobqueuearch) for more information.
  31  *
  32  * @stable to implement
  33  * @since 1.33
  34  * @ingroup JobQueue
  35  */
  36 interface RunnableJob extends IJobSpecification {
  37         /** @var int Job must not be wrapped in the usual explicit LBFactory transaction round */
  38         public const JOB_NO_EXPLICIT_TRX_ROUND = 1;
  39
  40         /**
  41          * Run the job.
  42          *
  43          * If this method returns `false` or completes exceptionally, the job runner will retry executing this
  44          * job unless the number of retries has exceeded its configured retry limit.
  45          * Retries are allowed by default, unless allowRetries() is overridden to disable retries.
  46          *
  47          * See [the architecture doc](@ref jobqueuearch) for more information.
  48          *
  49          * @return bool Return `false` to instruct the job runner to retry a failed job.
  50          * Otherwise return `true` to indicate that a job completed
  51          * (i.e. succeeded, or failed in a way that's deterministic or redundant).
  52          */
  53         public function run();
  54
  55         /**
  56          * @param string|null $field Metadata field or null to get all the metadata
  57          * @return mixed|null Value; null if missing
  58          */
  59         public function getMetadata( $field = null );
  60
  61         /**
  62          * @param string $field Key name to set the value for
  63          * @param mixed $value The value to set the field for
  64          * @return mixed|null The prior field value; null if missing
  65          */
  66         public function setMetadata( $field, $value );
  67
  68         /**
  69          * @param int $flag JOB_* class constant
  70          * @return bool
  71          * @since 1.31
  72          */
  73         public function hasExecutionFlag( $flag );
  74
  75         /**
  76          * @return string|null Id of the request that created this job. Follows
  77          *  jobs recursively, allowing to track the id of the request that started a
  78          *  job when jobs insert jobs which insert other jobs.
  79          * @since 1.27
  80          */
  81         public function getRequestId();
  82
  83         /**
  84          * Whether to retry execution of this job if run() returned `false` or threw an exception.
  85          *
  86          * @warning In some setups (i.e. when using change-propagation) jobs may
  87          *  still be retried even when this is false if the job fails due to a
  88          *  timeout unless it is also configured in change-prop config (T358939).
  89          * @return bool Whether this job can be retried on failure by job runners
  90          * @since 1.21
  91          */
  92         public function allowRetries();
  93
  94         /**
  95          * @return int Number of actually "work items" handled in this job
  96          * @see $wgJobBackoffThrottling
  97          * @since 1.23
  98          */
  99         public function workItemCount();
 100
 101         /**
 102          * @return int|null UNIX timestamp of when the job was runnable, or null
 103          * @since 1.26
 104          */
 105         public function getReadyTimestamp();
 106
 107         /**
 108          * Do any final cleanup after run(), deferred updates, and all DB commits happen
 109          * @param bool $status Whether the job, its deferred updates, and DB commit all succeeded
 110          * @since 1.27
 111          */
 112         public function tearDown( $status );
 113
 114         /**
 115          * @return string
 116          */
 117         public function getLastError();
 118
 119         /**
 120          * @return string Debugging string describing the job
 121          */
 122         public function toString();
 123 }