nextJobDB.php

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<?php
require_once __DIR__ . '/Maintenance.php';

class nextJobDB extends Maintenance {
    public function __construct() {
        parent::__construct();
        $this->mDescription = "Pick a database that has pending jobs";
        $this->addOption( 'type', "Search by job type", false, true );
        $this->addOption( 'types', "Space separated list of job types to search for", false, true );
    }

    public function execute() {
        global $wgJobTypesExcludedFromDefaultQueue;

        // job type required/picked
        if ( $this->hasOption( 'types' ) ) {
            $types = explode( ' ', $this->getOption( 'types' ) );
        } elseif ( $this->hasOption( 'type' ) ) {
            $types = array( $this->getOption( 'type' ) );
        } else {
            $types = false;
        }

        // Handle any required periodic queue maintenance
        $this->executeReadyPeriodicTasks();

        // Get all the queues with jobs in them
        $pendingDBs = JobQueueAggregator::singleton()->getAllReadyWikiQueues();
        if ( !count( $pendingDBs ) ) {
            return; // no DBs with jobs or cache is both empty and locked
        }

        do {
            $again = false;

            $candidates = array(); // list of (type, db)
            // Flatten the tree of candidates into a flat list so that a random
            // item can be selected, weighing each queue (type/db tuple) equally.
            foreach ( $pendingDBs as $type => $dbs ) {
                if (
                    ( is_array( $types ) && in_array( $type, $types ) ) ||
                    ( $types === false && !in_array( $type, $wgJobTypesExcludedFromDefaultQueue ) )
                ) {
                    foreach ( $dbs as $db ) {
                        $candidates[] = array( $type, $db );
                    }
                }
            }
            if ( !count( $candidates ) ) {
                return; // no jobs for this type
            }

            list( $type, $db ) = $candidates[mt_rand( 0, count( $candidates ) - 1 )];
            if ( JobQueueGroup::singleton( $db )->isQueueDeprioritized( $type ) ) {
                $pendingDBs[$type] = array_diff( $pendingDBs[$type], array( $db ) );
                $again = true;
            }
        } while ( $again );

        if ( $this->hasOption( 'types' ) ) {
            $this->output( $db . " " . $type . "\n" );
        } else {
            $this->output( $db . "\n" );
        }
    }

    private function executeReadyPeriodicTasks() {
        global $wgLocalDatabases, $wgMemc;

        $count = 0;
        $memcKey = 'jobqueue:periodic:lasttime';
        $timestamp = (int)$wgMemc->get( $memcKey ); // UNIX timestamp or 0
        if ( ( time() - $timestamp ) > 300 || mt_rand( 0, 999 ) == 0 ) { // 5 minutes
            if ( $wgMemc->add( "$memcKey:rebuild", 1, 1800 ) ) { // lock
                foreach ( $wgLocalDatabases as $db ) {
                    $count += JobQueueGroup::singleton( $db )->executeReadyPeriodicTasks();
                }
                $wgMemc->set( $memcKey, time() );
                $wgMemc->delete( "$memcKey:rebuild" ); // unlock
            }
        }

        return $count;
    }
}

$maintClass = "nextJobDb";
require_once RUN_MAINTENANCE_IF_MAIN;