<?php
+/**
+ * @defgroup JobQueue JobQueue
+ */
if ( !defined( 'MEDIAWIKI' ) ) {
die( "This file is part of MediaWiki, it is not a valid entry point\n" );
}
-class Job {
+/**
+ * Class to both describe a background job and handle jobs.
+ *
+ * @ingroup JobQueue
+ */
+abstract class Job {
var $command,
$title,
$params,
$removeDuplicates,
$error;
+ /*-------------------------------------------------------------------------
+ * Abstract functions
+ *------------------------------------------------------------------------*/
+
+ /**
+ * Run the job
+ * @return boolean success
+ */
+ abstract function run();
+
/*-------------------------------------------------------------------------
* Static functions
*------------------------------------------------------------------------*/
+
/**
- * Add an array of refreshLinks jobs to the queue
- * @param array $titles Array of title objects.
- * @static
+ * @deprecated use LinksUpdate::queueRecursiveJobs()
*/
- function queueLinksJobs( $titles ) {
- $fname = 'Job::queueLinksJobs';
- wfProfileIn( $fname );
- $batchSize = 100;
- for( $i = 0; $i < count( $titles ); $i += $batchSize ) {
- $batch = array_slice( $titles, $i, $batchSize, true );
- $jobs = array();
- foreach( $batch as $title ) {
- $jobs[] = new Job( 'refreshLinks', $title );
- }
- Job::batchInsert( $jobs );
+ /**
+ * 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;
}
- wfProfileOut( $fname );
+
+ $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->immediateCommit();
+
+ wfProfileOut( __METHOD__ );
+ return $job;
}
/**
* Pop a job off the front of the queue
- * @static
+ *
+ * @param $offset Number of jobs to skip
* @return Job or false if there's no jobs
*/
- function pop() {
- $fname = 'Job::pop';
- wfProfileIn( $fname );
+ static function pop($offset=0) {
+ wfProfileIn( __METHOD__ );
- $dbr =& wfGetDB( DB_SLAVE );
+ $dbr = wfGetDB( DB_SLAVE );
- // Get a job from the slave
- $row = $dbr->selectRow( 'job', '*', '', $fname,
- array( 'ORDER BY' => 'job_id', 'LIMIT' => 1 )
- );
+ /* Get a job from the slave, start with an offset,
+ scan full set afterwards, avoid hitting purged rows
- if ( $row === false ) {
- wfProfileOut( $fname );
- return false;
+ 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 ));
+
+ // 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)
+ $row = $dbr->selectRow( 'job', '*', '', __METHOD__,
+ array( 'ORDER BY' => 'job_id', 'LIMIT' => 1 ));
+
+ if ($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 ), $fname );
+ $dbw = wfGetDB( DB_MASTER );
+ $dbw->delete( 'job', array( 'job_id' => $row->job_id ), __METHOD__ );
$affected = $dbw->affectedRows();
$dbw->immediateCommit();
// 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' ), '', $fname );
+ 'MAX(job_id) as maxjob' ), '1=1', __METHOD__ );
if ( $row === false || is_null( $row->minjob ) || is_null( $row->maxjob ) ) {
// No jobs to get
- wfProfileOut( $fname );
+ wfProfileOut( __METHOD__ );
return false;
}
// Get the random row
$row = $dbw->selectRow( 'job', '*',
- array( 'job_id' => mt_rand( $row->minjob, $row->maxjob ) ), $fname );
+ '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
- wfProfileOut( $fname );
+ wfProfileOut( __METHOD__ );
return false;
}
// Delete the random row
- $dbw->delete( 'job', array( 'job_id' => $row->job_id ), $fname );
+ $dbw->delete( 'job', array( 'job_id' => $row->job_id ), __METHOD__ );
$affected = $dbw->affectedRows();
$dbw->immediateCommit();
-
+
if ( !$affected ) {
// Random job gone before we exclusively deleted it
// Give up
- wfProfileOut( $fname );
+ wfProfileOut( __METHOD__ );
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 = new Job( $row->job_cmd, $title, $row->job_params, $row->job_id );
-
+ $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
- $dbw->delete( 'job', $job->insertFields(), $fname );
-
- wfProfileOut( $fname );
+ // Deadlock prone section
+ $dbw->begin();
+ $dbw->delete( 'job', $job->insertFields(), __METHOD__ );
+ $dbw->commit();
+
+ wfProfileOut( __METHOD__ );
return $job;
}
+ /**
+ * 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 ) {
+ 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 ) {
+ if ( $params !== false ) {
+ return serialize( $params );
+ } else {
+ return '';
+ }
+ }
+
+ static function extractBlob( $blob ) {
+ if ( (string)$blob !== '' ) {
+ return unserialize( $blob );
+ } else {
+ return false;
+ }
+ }
+
+ /**
+ * 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
*------------------------------------------------------------------------*/
- function Job( $command, $title, $params = '', $id = 0 ) {
+ function __construct( $command, $title, $params = false, $id = 0 ) {
$this->command = $command;
$this->title = $title;
$this->params = $params;
* Insert a single job into the queue.
*/
function insert() {
- $fname = 'Job::insert';
-
$fields = $this->insertFields();
- $dbw =& wfGetDB( DB_MASTER );
-
+ $dbw = wfGetDB( DB_MASTER );
+
if ( $this->removeDuplicates ) {
- $res = $dbw->select( 'job', array( '1' ), $fields, $fname );
+ $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, $fname );
+ $dbw->insert( 'job', $fields, __METHOD__ );
}
-
+
protected function insertFields() {
return array(
'job_cmd' => $this->command,
'job_namespace' => $this->title->getNamespace(),
'job_title' => $this->title->getDBkey(),
- 'job_params' => $this->params
+ '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 ) {
- $fname = __CLASS__ . '::' . __FUNCTION__;
-
- if( count( $jobs ) ) {
- $dbw = wfGetDB( DB_MASTER );
- $dbw->begin();
- foreach( $jobs as $job ) {
- $rows[] = $job->insertFields();
- }
- $dbw->insert( 'job', $rows, $fname, 'IGNORE' );
- $dbw->immediateCommit();
- }
- }
- /**
- * Run the job
- * @return boolean success
- */
- function run() {
- $fname = 'Job::run';
- wfProfileIn( $fname );
- switch ( $this->command ) {
- case 'refreshLinks':
- $retval = $this->refreshLinks();
- break;
- default:
- $retval = true;
- if( wfRunHooks( 'RunUnknownJob', array( &$this, &$retval ) ) ) {
- $this->error = "Invalid job type {$this->command}, ignoring";
- wfDebug( $this->error . "\n" );
- $retval = false;
- } else {
- $retval = true;
+ function toString() {
+ $paramString = '';
+ if ( $this->params ) {
+ foreach ( $this->params as $key => $value ) {
+ if ( $paramString != '' ) {
+ $paramString .= ' ';
}
+ $paramString .= "$key=$value";
+ }
}
- wfProfileOut( $fname );
- return $retval;
- }
-
- /**
- * Run a refreshLinks job
- * @return boolean success
- */
- function refreshLinks() {
- global $wgParser;
- $fname = 'Job::refreshLinks';
- wfProfileIn( $fname );
-
- # FIXME: $dbw never used.
- $dbw =& wfGetDB( DB_MASTER );
-
- $linkCache =& LinkCache::singleton();
- $linkCache->clear();
-
- if ( is_null( $this->title ) ) {
- $this->error = "refreshLinks: Invalid title";
- wfProfileOut( $fname );
- return false;
- }
-
- $revision = Revision::newFromTitle( $this->title );
- if ( !$revision ) {
- $this->error = 'refreshLinks: Article not found "' . $this->title->getPrefixedDBkey() . '"';
- wfProfileOut( $fname );
- return false;
- }
-
- wfProfileIn( "$fname-parse" );
- $options = new ParserOptions;
- $parserOutput = $wgParser->parse( $revision->getText(), $this->title, $options, true, true, $revision->getId() );
- wfProfileOut( "$fname-parse" );
- wfProfileIn( "$fname-update" );
- $update = new LinksUpdate( $this->title, $parserOutput, false );
- $update->doUpdate();
- wfProfileOut( "$fname-update" );
- wfProfileOut( $fname );
- return true;
- }
- function toString() {
if ( is_object( $this->title ) ) {
$s = "{$this->command} " . $this->title->getPrefixedDBkey();
- if ( $this->params !== '' ) {
- $s .= ', ' . $this->params;
+ if ( $paramString !== '' ) {
+ $s .= ' ' . $paramString;
}
return $s;
} else {
- return "{$this->command} {$this->params}";
+ return "{$this->command} $paramString";
}
}
+ protected function setLastError( $error ) {
+ $this->error = $error;
+ }
+
function getLastError() {
return $this->error;
}
}
-?>
dépôts / lhc / web / wiklou.git / blobdiff