<?php
+/**
+ * @defgroup JobQueue JobQueue
+ */
if ( !defined( 'MEDIAWIKI' ) ) {
die( "This file is part of MediaWiki, it is not a valid entry point\n" );
}
+/**
+ * Class to both describe a background job and handle jobs.
+ *
+ * @ingroup JobQueue
+ */
abstract class Job {
var $command,
$title,
$removeDuplicates,
$error;
+ /*-------------------------------------------------------------------------
+ * Abstract functions
+ *------------------------------------------------------------------------*/
+
+ /**
+ * Run the job
+ * @return boolean success
+ */
+ abstract function run();
+
/*-------------------------------------------------------------------------
* Static functions
*------------------------------------------------------------------------*/
- /**
+ /**
* @deprecated use LinksUpdate::queueRecursiveJobs()
*/
/**
* static function queueLinksJobs( $titles ) {}
*/
+ /**
+ * Pop a job of a certain type. This tries less hard than pop() to
+ * actually find a job; it may be adversely affected by concurrent job
+ * runners.
+ */
+ static function pop_type( $type ) {
+ wfProfilein( __METHOD__ );
+
+ $dbw = wfGetDB( DB_MASTER );
+
+ $row = $dbw->selectRow(
+ 'job',
+ '*',
+ array( 'job_cmd' => $type ),
+ __METHOD__,
+ array( 'LIMIT' => 1 )
+ );
+
+ if ( $row === false ) {
+ wfProfileOut( __METHOD__ );
+ return false;
+ }
+
+ /* Ensure we "own" this row */
+ $dbw->delete( 'job', array( 'job_id' => $row->job_id ), __METHOD__ );
+ $affected = $dbw->affectedRows();
+
+ if ( $affected == 0 ) {
+ wfProfileOut( __METHOD__ );
+ return false;
+ }
+
+ $namespace = $row->job_namespace;
+ $dbkey = $row->job_title;
+ $title = Title::makeTitleSafe( $namespace, $dbkey );
+ $job = Job::factory( $row->job_cmd, $title, Job::extractBlob( $row->job_params ), $row->job_id );
+
+ $dbw->delete( 'job', $job->insertFields(), __METHOD__ );
+ $dbw->commit();
+
+ wfProfileOut( __METHOD__ );
+ return $job;
+ }
+
/**
* Pop a job off the front of the queue
- * @static
- * @param $offset Number of jobs to skip
+ *
+ * @param $offset Integer: Number of jobs to skip
* @return Job or false if there's no jobs
*/
- static function pop($offset=0) {
+ static function pop( $offset = 0 ) {
wfProfileIn( __METHOD__ );
$dbr = wfGetDB( DB_SLAVE );
- /* Get a job from the slave, start with an offset,
+ /* Get a job from the slave, start with an offset,
scan full set afterwards, avoid hitting purged rows
-
- NB: If random fetch previously was used, offset
- will always be ahead of few entries
+
+ NB: If random fetch previously was used, offset
+ will always be ahead of few entries
*/
-
+
$row = $dbr->selectRow( 'job', '*', "job_id >= ${offset}", __METHOD__,
- array( 'ORDER BY' => 'job_id', 'LIMIT' => 1 ));
-
+ array( 'ORDER BY' => 'job_id', 'LIMIT' => 1 ) );
+
// Refetching without offset is needed as some of job IDs could have had delayed commits
// and have lower IDs than jobs already executed, blame concurrency :)
- //
- if ( $row === false) {
- if ($offset!=0)
+ //
+ if ( $row === false ) {
+ if ( $offset != 0 ) {
$row = $dbr->selectRow( 'job', '*', '', __METHOD__,
- array( 'ORDER BY' => 'job_id', 'LIMIT' => 1 ));
-
- if ($row === false ) {
+ array( 'ORDER BY' => 'job_id', 'LIMIT' => 1 ) );
+ }
+
+ if ( $row === false ) {
wfProfileOut( __METHOD__ );
return false;
- }
- }
+ }
+ }
$offset = $row->job_id;
-
+
// Try to delete it from the master
$dbw = wfGetDB( DB_MASTER );
$dbw->delete( 'job', array( 'job_id' => $row->job_id ), __METHOD__ );
$affected = $dbw->affectedRows();
- $dbw->immediateCommit();
+ $dbw->commit();
if ( !$affected ) {
// Failed, someone else beat us to it
// Try getting a random row
$row = $dbw->selectRow( 'job', array( 'MIN(job_id) as minjob',
- 'MAX(job_id) as maxjob' ), "job_id >= $offset", __METHOD__ );
+ 'MAX(job_id) as maxjob' ), '1=1', __METHOD__ );
if ( $row === false || is_null( $row->minjob ) || is_null( $row->maxjob ) ) {
// No jobs to get
wfProfileOut( __METHOD__ );
}
// Get the random row
$row = $dbw->selectRow( 'job', '*',
- 'job_id >= ' . mt_rand( $row->minjob, $row->maxjob ), __METHOD__ );
+ 'job_id >= ' . mt_rand( $row->minjob, $row->maxjob ), __METHOD__ );
if ( $row === false ) {
// Random job gone before we got the chance to select it
// Give up
// Delete the random row
$dbw->delete( 'job', array( 'job_id' => $row->job_id ), __METHOD__ );
$affected = $dbw->affectedRows();
- $dbw->immediateCommit();
-
+ $dbw->commit();
+
if ( !$affected ) {
// Random job gone before we exclusively deleted it
// Give up
return false;
}
}
-
+
// If execution got to here, there's a row in $row that has been deleted from the database
// by this thread. Hence the concurrent pop was successful.
$namespace = $row->job_namespace;
$dbkey = $row->job_title;
$title = Title::makeTitleSafe( $namespace, $dbkey );
$job = Job::factory( $row->job_cmd, $title, Job::extractBlob( $row->job_params ), $row->job_id );
-
+
// Remove any duplicates it may have later in the queue
+ // Deadlock prone section
+ $dbw->begin();
$dbw->delete( 'job', $job->insertFields(), __METHOD__ );
-
+ $dbw->commit();
+
wfProfileOut( __METHOD__ );
return $job;
}
- /**
- * Create an object of a subclass
+ /**
+ * Create the appropriate object to handle a specific job
+ *
+ * @param $command String: Job command
+ * @param $title Title: Associated title
+ * @param $params Array: Job parameters
+ * @param $id Int: Job identifier
+ * @return Job
*/
static function factory( $command, $title, $params = false, $id = 0 ) {
- switch ( $command ) {
- case 'refreshLinks':
- return new RefreshLinksJob( $title, $params, $id );
- case 'htmlCacheUpdate':
- case 'html_cache_update': # BC
- return new HTMLCacheUpdateJob( $title, $params['table'], $params['start'], $params['end'], $id );
- default:
- throw new MWException( "Invalid job command \"$command\"" );
+ global $wgJobClasses;
+ if( isset( $wgJobClasses[$command] ) ) {
+ $class = $wgJobClasses[$command];
+ return new $class( $title, $params, $id );
}
+ throw new MWException( "Invalid job command `{$command}`" );
}
static function makeBlob( $params ) {
}
}
+ /**
+ * Batch-insert a group of jobs into the queue.
+ * This will be wrapped in a transaction with a forced commit.
+ *
+ * This may add duplicate at insert time, but they will be
+ * removed later on, when the first one is popped.
+ *
+ * @param $jobs array of Job objects
+ */
+ static function batchInsert( $jobs ) {
+ if( !count( $jobs ) ) {
+ return;
+ }
+ $dbw = wfGetDB( DB_MASTER );
+ $rows = array();
+ foreach( $jobs as $job ) {
+ $rows[] = $job->insertFields();
+ if ( count( $rows ) >= 50 ) {
+ # Do a small transaction to avoid slave lag
+ $dbw->begin();
+ $dbw->insert( 'job', $rows, __METHOD__, 'IGNORE' );
+ $dbw->commit();
+ $rows = array();
+ }
+ }
+ if ( $rows ) {
+ $dbw->begin();
+ $dbw->insert( 'job', $rows, __METHOD__, 'IGNORE' );
+ $dbw->commit();
+ }
+ }
+
/*-------------------------------------------------------------------------
* Non-static functions
*------------------------------------------------------------------------*/
$fields = $this->insertFields();
$dbw = wfGetDB( DB_MASTER );
-
+
if ( $this->removeDuplicates ) {
$res = $dbw->select( 'job', array( '1' ), $fields, __METHOD__ );
if ( $dbw->numRows( $res ) ) {
return;
}
}
- $fields['job_id'] = $dbw->nextSequenceValue( 'job_job_id_seq' );
$dbw->insert( 'job', $fields, __METHOD__ );
}
-
+
protected function insertFields() {
+ $dbw = wfGetDB( DB_MASTER );
return array(
+ 'job_id' => $dbw->nextSequenceValue( 'job_job_id_seq' ),
'job_cmd' => $this->command,
'job_namespace' => $this->title->getNamespace(),
'job_title' => $this->title->getDBkey(),
'job_params' => Job::makeBlob( $this->params )
);
}
-
- /**
- * Batch-insert a group of jobs into the queue.
- * This will be wrapped in a transaction with a forced commit.
- *
- * This may add duplicate at insert time, but they will be
- * removed later on, when the first one is popped.
- *
- * @param $jobs array of Job objects
- */
- static function batchInsert( $jobs ) {
- if( count( $jobs ) ) {
- $dbw = wfGetDB( DB_MASTER );
- $dbw->begin();
- foreach( $jobs as $job ) {
- $rows[] = $job->insertFields();
- }
- $dbw->insert( 'job', $rows, __METHOD__, 'IGNORE' );
- $dbw->commit();
- }
- }
- /**
- * Run the job
- * @return boolean success
- */
- abstract function run();
-
function toString() {
$paramString = '';
if ( $this->params ) {
}
}
- function getLastError() {
- return $this->error;
+ protected function setLastError( $error ) {
+ $this->error = $error;
}
-}
-
-class RefreshLinksJob extends Job {
- function __construct( $title, $params = '', $id = 0 ) {
- parent::__construct( 'refreshLinks', $title, $params, $id );
- }
-
- /**
- * Run a refreshLinks job
- * @return boolean success
- */
- function run() {
- global $wgParser;
- wfProfileIn( __METHOD__ );
-
- $linkCache =& LinkCache::singleton();
- $linkCache->clear();
-
- if ( is_null( $this->title ) ) {
- $this->error = "refreshLinks: Invalid title";
- wfProfileOut( __METHOD__ );
- return false;
- }
- $revision = Revision::newFromTitle( $this->title );
- if ( !$revision ) {
- $this->error = 'refreshLinks: Article not found "' . $this->title->getPrefixedDBkey() . '"';
- wfProfileOut( __METHOD__ );
- return false;
- }
-
- wfProfileIn( __METHOD__.'-parse' );
- $options = new ParserOptions;
- $parserOutput = $wgParser->parse( $revision->getText(), $this->title, $options, true, true, $revision->getId() );
- wfProfileOut( __METHOD__.'-parse' );
- wfProfileIn( __METHOD__.'-update' );
- $update = new LinksUpdate( $this->title, $parserOutput, false );
- $update->doUpdate();
- wfProfileOut( __METHOD__.'-update' );
- wfProfileOut( __METHOD__ );
- return true;
+ function getLastError() {
+ return $this->error;
}
}
-
-?>
dépôts / lhc / web / wiklou.git / blobdiff