From 63601400e476c6cf43d985f3e7b9864681695ed4 Mon Sep 17 00:00:00 2001 From: Pierre Schmitz Date: Fri, 18 Jan 2013 16:46:04 +0100 Subject: Update to MediaWiki 1.20.2 this update includes: * adjusted Arch Linux skin * updated FluxBBAuthPlugin * patch for https://bugzilla.wikimedia.org/show_bug.cgi?id=44024 --- includes/job/Job.php | 447 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 447 insertions(+) create mode 100644 includes/job/Job.php (limited to 'includes/job/Job.php') diff --git a/includes/job/Job.php b/includes/job/Job.php new file mode 100644 index 00000000..d777a5d4 --- /dev/null +++ b/includes/job/Job.php @@ -0,0 +1,447 @@ +begin( __METHOD__ ); + + $row = $dbw->selectRow( + 'job', + '*', + array( 'job_cmd' => $type ), + __METHOD__, + array( 'LIMIT' => 1, 'FOR UPDATE' ) + ); + + if ( $row === false ) { + $dbw->commit( __METHOD__ ); + wfProfileOut( __METHOD__ ); + return false; + } + + /* Ensure we "own" this row */ + $dbw->delete( 'job', array( 'job_id' => $row->job_id ), __METHOD__ ); + $affected = $dbw->affectedRows(); + $dbw->commit( __METHOD__ ); + + if ( $affected == 0 ) { + wfProfileOut( __METHOD__ ); + return false; + } + + wfIncrStats( 'job-pop' ); + $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 ); + + $job->removeDuplicates(); + + wfProfileOut( __METHOD__ ); + return $job; + } + + /** + * Pop a job off the front of the queue + * + * @param $offset Integer: Number of jobs to skip + * @return Job or false if there's no jobs + */ + static function pop( $offset = 0 ) { + wfProfileIn( __METHOD__ ); + + $dbr = wfGetDB( DB_SLAVE ); + + /* 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 + */ + + $conditions = self::defaultQueueConditions(); + + $offset = intval( $offset ); + $options = array( 'ORDER BY' => 'job_id', 'USE INDEX' => 'PRIMARY' ); + + $row = $dbr->selectRow( 'job', '*', + array_merge( $conditions, array( "job_id >= $offset" ) ), + __METHOD__, + $options + ); + + // 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', '*', $conditions, __METHOD__, $options ); + } + + 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 = $dbw->affectedRows(); + + if ( !$affected ) { + // Failed, someone else beat us to it + // Try getting a random row + $row = $dbw->selectRow( 'job', array( 'minjob' => 'MIN(job_id)', + 'maxjob' => 'MAX(job_id)' ), '1=1', __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', '*', + '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 = $dbw->affectedRows(); + + if ( !$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. + wfIncrStats( 'job-pop' ); + $namespace = $row->job_namespace; + $dbkey = $row->job_title; + $title = Title::makeTitleSafe( $namespace, $dbkey ); + + if ( is_null( $title ) ) { + wfProfileOut( __METHOD__ ); + return false; + } + + $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 + $job->removeDuplicates(); + + 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|bool: Job parameters + * @param $id Int: Job identifier + * @throws MWException + * @return Job + */ + static function factory( $command, Title $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}`" ); + } + + /** + * @param $params + * @return string + */ + static function makeBlob( $params ) { + if ( $params !== false ) { + return serialize( $params ); + } else { + return ''; + } + } + + /** + * @param $blob + * @return bool|mixed + */ + 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(); + + /** + * @var $job Job + */ + foreach ( $jobs as $job ) { + $rows[] = $job->insertFields(); + if ( count( $rows ) >= 50 ) { + # Do a small transaction to avoid slave lag + $dbw->begin( __METHOD__ ); + $dbw->insert( 'job', $rows, __METHOD__, 'IGNORE' ); + $dbw->commit( __METHOD__ ); + $rows = array(); + } + } + if ( $rows ) { // last chunk + $dbw->begin( __METHOD__ ); + $dbw->insert( 'job', $rows, __METHOD__, 'IGNORE' ); + $dbw->commit( __METHOD__ ); + } + wfIncrStats( 'job-insert', count( $jobs ) ); + } + + /** + * Insert a group of jobs into the queue. + * + * Same as batchInsert() but does not commit and can thus + * be rolled-back as part of a larger transaction. However, + * large batches of jobs can cause slave lag. + * + * @param $jobs array of Job objects + */ + static function safeBatchInsert( $jobs ) { + if ( !count( $jobs ) ) { + return; + } + $dbw = wfGetDB( DB_MASTER ); + $rows = array(); + foreach ( $jobs as $job ) { + $rows[] = $job->insertFields(); + if ( count( $rows ) >= 500 ) { + $dbw->insert( 'job', $rows, __METHOD__, 'IGNORE' ); + $rows = array(); + } + } + if ( $rows ) { // last chunk + $dbw->insert( 'job', $rows, __METHOD__, 'IGNORE' ); + } + wfIncrStats( 'job-insert', count( $jobs ) ); + } + + + /** + * SQL conditions to apply on most JobQueue queries + * + * Whenever we exclude jobs types from the default queue, we want to make + * sure that queries to the job queue actually ignore them. + * + * @return array SQL conditions suitable for Database:: methods + */ + static function defaultQueueConditions( ) { + global $wgJobTypesExcludedFromDefaultQueue; + $conditions = array(); + if ( count( $wgJobTypesExcludedFromDefaultQueue ) > 0 ) { + $dbr = wfGetDB( DB_SLAVE ); + foreach ( $wgJobTypesExcludedFromDefaultQueue as $cmdType ) { + $conditions[] = "job_cmd != " . $dbr->addQuotes( $cmdType ); + } + } + return $conditions; + } + + /*------------------------------------------------------------------------- + * Non-static functions + *------------------------------------------------------------------------*/ + + /** + * @param $command + * @param $title + * @param $params array|bool + * @param $id int + */ + 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. + * @return bool true on success + */ + 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 true; + } + } + wfIncrStats( 'job-insert' ); + return $dbw->insert( 'job', $fields, __METHOD__ ); + } + + /** + * @return array + */ + 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_timestamp' => $dbw->timestamp(), + 'job_params' => Job::makeBlob( $this->params ) + ); + } + + /** + * Remove jobs in the job queue which are duplicates of this job. + * This is deadlock-prone and so starts its own transaction. + */ + function removeDuplicates() { + if ( !$this->removeDuplicates ) { + return; + } + + $fields = $this->insertFields(); + unset( $fields['job_id'] ); + unset( $fields['job_timestamp'] ); + $dbw = wfGetDB( DB_MASTER ); + $dbw->begin( __METHOD__ ); + $dbw->delete( 'job', $fields, __METHOD__ ); + $affected = $dbw->affectedRows(); + $dbw->commit( __METHOD__ ); + if ( $affected ) { + wfIncrStats( 'job-dup-delete', $affected ); + } + } + + /** + * @return string + */ + 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"; + } + } + + protected function setLastError( $error ) { + $this->error = $error; + } + + function getLastError() { + return $this->error; + } +} -- cgit v1.2.2