Current File : /www/varak.net/wiki.varak.net/includes/jobqueue/Job.php
<?php
/**
* Job queue task base code.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
* @defgroup JobQueue JobQueue
*/
/**
* Class to both describe a background job and handle jobs.
* To push jobs onto queues, use JobQueueGroup::singleton()->push();
*
* @ingroup JobQueue
*/
abstract class Job implements IJobSpecification {
/** @var string */
public $command;
/** @var array Array of job parameters */
public $params;
/** @var array Additional queue metadata */
public $metadata = [];
/** @var Title */
protected $title;
/** @var bool Expensive jobs may set this to true */
protected $removeDuplicates;
/** @var string Text for error that occurred last */
protected $error;
/** @var callable[] */
protected $teardownCallbacks = [];
/** @var int Bitfield of JOB_* class constants */
protected $executionFlags = 0;
/** @var int Job must not be wrapped in the usual explicit LBFactory transaction round */
const JOB_NO_EXPLICIT_TRX_ROUND = 1;
/**
* Run the job
* @return bool Success
*/
abstract public function run();
/**
* Create the appropriate object to handle a specific job
*
* @param string $command Job command
* @param Title $title Associated title
* @param array $params Job parameters
* @throws MWException
* @return Job
*/
public static function factory( $command, Title $title, $params = [] ) {
global $wgJobClasses;
if ( isset( $wgJobClasses[$command] ) ) {
$handler = $wgJobClasses[$command];
if ( is_callable( $handler ) ) {
$job = call_user_func( $handler, $title, $params );
} elseif ( class_exists( $handler ) ) {
$job = new $handler( $title, $params );
} else {
$job = null;
}
if ( $job instanceof Job ) {
$job->command = $command;
return $job;
} else {
throw new InvalidArgumentException( "Cannot instantiate job '$command': bad spec!" );
}
}
throw new InvalidArgumentException( "Invalid job command '{$command}'" );
}
/**
* @param string $command
* @param Title $title
* @param array|bool $params Can not be === true
*/
public function __construct( $command, $title, $params = false ) {
$this->command = $command;
$this->title = $title;
$this->params = is_array( $params ) ? $params : []; // sanity
// expensive jobs may set this to true
$this->removeDuplicates = false;
if ( !isset( $this->params['requestId'] ) ) {
$this->params['requestId'] = WebRequest::getRequestId();
}
}
/**
* @param int $flag JOB_* class constant
* @return bool
* @since 1.31
*/
public function hasExecutionFlag( $flag ) {
return ( $this->executionFlags && $flag ) === $flag;
}
/**
* @return string
*/
public function getType() {
return $this->command;
}
/**
* @return Title
*/
public function getTitle() {
return $this->title;
}
/**
* @return array
*/
public function getParams() {
return $this->params;
}
/**
* @return int|null UNIX timestamp to delay running this job until, otherwise null
* @since 1.22
*/
public function getReleaseTimestamp() {
return isset( $this->params['jobReleaseTimestamp'] )
? wfTimestampOrNull( TS_UNIX, $this->params['jobReleaseTimestamp'] )
: null;
}
/**
* @return int|null UNIX timestamp of when the job was queued, or null
* @since 1.26
*/
public function getQueuedTimestamp() {
return isset( $this->metadata['timestamp'] )
? wfTimestampOrNull( TS_UNIX, $this->metadata['timestamp'] )
: null;
}
/**
* @return string|null Id of the request that created this job. Follows
* jobs recursively, allowing to track the id of the request that started a
* job when jobs insert jobs which insert other jobs.
* @since 1.27
*/
public function getRequestId() {
return $this->params['requestId'] ?? null;
}
/**
* @return int|null UNIX timestamp of when the job was runnable, or null
* @since 1.26
*/
public function getReadyTimestamp() {
return $this->getReleaseTimestamp() ?: $this->getQueuedTimestamp();
}
/**
* Whether the queue should reject insertion of this job if a duplicate exists
*
* This can be used to avoid duplicated effort or combined with delayed jobs to
* coalesce updates into larger batches. Claimed jobs are never treated as
* duplicates of new jobs, and some queues may allow a few duplicates due to
* network partitions and fail-over. Thus, additional locking is needed to
* enforce mutual exclusion if this is really needed.
*
* @return bool
*/
public function ignoreDuplicates() {
return $this->removeDuplicates;
}
/**
* @return bool Whether this job can be retried on failure by job runners
* @since 1.21
*/
public function allowRetries() {
return true;
}
/**
* @return int Number of actually "work items" handled in this job
* @see $wgJobBackoffThrottling
* @since 1.23
*/
public function workItemCount() {
return 1;
}
/**
* Subclasses may need to override this to make duplication detection work.
* The resulting map conveys everything that makes the job unique. This is
* only checked if ignoreDuplicates() returns true, meaning that duplicate
* jobs are supposed to be ignored.
*
* @return array Map of key/values
* @since 1.21
*/
public function getDeduplicationInfo() {
$info = [
'type' => $this->getType(),
'namespace' => $this->getTitle()->getNamespace(),
'title' => $this->getTitle()->getDBkey(),
'params' => $this->getParams()
];
if ( is_array( $info['params'] ) ) {
// Identical jobs with different "root" jobs should count as duplicates
unset( $info['params']['rootJobSignature'] );
unset( $info['params']['rootJobTimestamp'] );
// Likewise for jobs with different delay times
unset( $info['params']['jobReleaseTimestamp'] );
// Identical jobs from different requests should count as duplicates
unset( $info['params']['requestId'] );
// Queues pack and hash this array, so normalize the order
ksort( $info['params'] );
}
return $info;
}
/**
* Get "root job" parameters for a task
*
* This is used to no-op redundant jobs, including child jobs of jobs,
* as long as the children inherit the root job parameters. When a job
* with root job parameters and "rootJobIsSelf" set is pushed, the
* deduplicateRootJob() method is automatically called on it. If the
* root job is only virtual and not actually pushed (e.g. the sub-jobs
* are inserted directly), then call deduplicateRootJob() directly.
*
* @see JobQueue::deduplicateRootJob()
*
* @param string $key A key that identifies the task
* @return array Map of:
* - rootJobIsSelf : true
* - rootJobSignature : hash (e.g. SHA1) that identifies the task
* - rootJobTimestamp : TS_MW timestamp of this instance of the task
* @since 1.21
*/
public static function newRootJobParams( $key ) {
return [
'rootJobIsSelf' => true,
'rootJobSignature' => sha1( $key ),
'rootJobTimestamp' => wfTimestampNow()
];
}
/**
* @see JobQueue::deduplicateRootJob()
* @return array
* @since 1.21
*/
public function getRootJobParams() {
return [
'rootJobSignature' => $this->params['rootJobSignature'] ?? null,
'rootJobTimestamp' => $this->params['rootJobTimestamp'] ?? null
];
}
/**
* @see JobQueue::deduplicateRootJob()
* @return bool
* @since 1.22
*/
public function hasRootJobParams() {
return isset( $this->params['rootJobSignature'] )
&& isset( $this->params['rootJobTimestamp'] );
}
/**
* @see JobQueue::deduplicateRootJob()
* @return bool Whether this is job is a root job
*/
public function isRootJob() {
return $this->hasRootJobParams() && !empty( $this->params['rootJobIsSelf'] );
}
/**
* @param callable $callback A function with one parameter, the success status, which will be
* false if the job failed or it succeeded but the DB changes could not be committed or
* any deferred updates threw an exception. (This parameter was added in 1.28.)
* @since 1.27
*/
protected function addTeardownCallback( $callback ) {
$this->teardownCallbacks[] = $callback;
}
/**
* Do any final cleanup after run(), deferred updates, and all DB commits happen
* @param bool $status Whether the job, its deferred updates, and DB commit all succeeded
* @since 1.27
*/
public function teardown( $status ) {
foreach ( $this->teardownCallbacks as $callback ) {
call_user_func( $callback, $status );
}
}
/**
* @return string
*/
public function toString() {
$paramString = '';
if ( $this->params ) {
foreach ( $this->params as $key => $value ) {
if ( $paramString != '' ) {
$paramString .= ' ';
}
if ( is_array( $value ) ) {
$filteredValue = [];
foreach ( $value as $k => $v ) {
$json = FormatJson::encode( $v );
if ( $json === false || mb_strlen( $json ) > 512 ) {
$filteredValue[$k] = gettype( $v ) . '(...)';
} else {
$filteredValue[$k] = $v;
}
}
if ( count( $filteredValue ) <= 10 ) {
$value = FormatJson::encode( $filteredValue );
} else {
$value = "array(" . count( $value ) . ")";
}
} elseif ( is_object( $value ) && !method_exists( $value, '__toString' ) ) {
$value = "object(" . get_class( $value ) . ")";
}
$flatValue = (string)$value;
if ( mb_strlen( $value ) > 1024 ) {
$flatValue = "string(" . mb_strlen( $value ) . ")";
}
$paramString .= "$key={$flatValue}";
}
}
$metaString = '';
foreach ( $this->metadata as $key => $value ) {
if ( is_scalar( $value ) && mb_strlen( $value ) < 1024 ) {
$metaString .= ( $metaString ? ",$key=$value" : "$key=$value" );
}
}
$s = $this->command;
if ( is_object( $this->title ) ) {
$s .= " {$this->title->getPrefixedDBkey()}";
}
if ( $paramString != '' ) {
$s .= " $paramString";
}
if ( $metaString != '' ) {
$s .= " ($metaString)";
}
return $s;
}
protected function setLastError( $error ) {
$this->error = $error;
}
public function getLastError() {
return $this->error;
}
}
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