wiki.techinc.nl/includes/JobQueue.php

267 lines
6.7 KiB
PHP

<?php
if ( !defined( 'MEDIAWIKI' ) ) {
die( "This file is part of MediaWiki, it is not a valid entry point\n" );
}
abstract class Job {
var $command,
$title,
$params,
$id,
$removeDuplicates,
$error;
/*-------------------------------------------------------------------------
* Static functions
*------------------------------------------------------------------------*/
/**
* @deprecated use LinksUpdate::queueRecursiveJobs()
*/
/**
* static function queueLinksJobs( $titles ) {}
*/
/**
* Pop a job off the front of the queue
* @static
* @return Job or false if there's no jobs
*/
static function pop() {
wfProfileIn( __METHOD__ );
$dbr =& wfGetDB( DB_SLAVE );
// Get a job from the slave
$row = $dbr->selectRow( 'job', '*', '', __METHOD__,
array( 'ORDER BY' => 'job_id', 'LIMIT' => 1 )
);
if ( $row === false ) {
wfProfileOut( __METHOD__ );
return false;
}
// Try to delete it from the master
$dbw =& wfGetDB( DB_MASTER );
$dbw->delete( 'job', array( 'job_id' => $row->job_id ), __METHOD__ );
$affected = $dbw->affectedRows();
$dbw->immediateCommit();
if ( !$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' ), '', __METHOD__ );
if ( $row === false || is_null( $row->minjob ) || is_null( $row->maxjob ) ) {
// No jobs to get
wfProfileOut( __METHOD__ );
return false;
}
// Get the random row
$row = $dbw->selectRow( 'job', '*',
array( '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( __METHOD__ );
return false;
}
// Delete the random row
$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( __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 = 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(), __METHOD__ );
wfProfileOut( __METHOD__ );
return $job;
}
/**
* Create an object of a subclass
*/
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\"" );
}
}
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;
}
}
/*-------------------------------------------------------------------------
* Non-static functions
*------------------------------------------------------------------------*/
function __construct( $command, $title, $params = false, $id = 0 ) {
$this->command = $command;
$this->title = $title;
$this->params = $params;
$this->id = $id;
// A bit of premature generalisation
// Oh well, the whole class is premature generalisation really
$this->removeDuplicates = true;
}
/**
* Insert a single job into the queue.
*/
function insert() {
$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() {
return array(
'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 ) {
foreach ( $this->params as $key => $value ) {
if ( $paramString != '' ) {
$paramString .= ' ';
}
$paramString .= "$key=$value";
}
}
if ( is_object( $this->title ) ) {
$s = "{$this->command} " . $this->title->getPrefixedDBkey();
if ( $paramString !== '' ) {
$s .= ' ' . $paramString;
}
return $s;
} else {
return "{$this->command} $paramString";
}
}
function getLastError() {
return $this->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;
}
}
?>