RefreshLinksJob2.php

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<?php
class RefreshLinksJob2 extends Job {
    function __construct( $title, $params ) {
        parent::__construct( 'refreshLinks2', $title, $params );
        // Base jobs for large templates can easily be de-duplicated
        $this->removeDuplicates = !isset( $params['start'] ) && !isset( $params['end'] );
    }

    function run() {
        global $wgUpdateRowsPerJob;

        $linkCache = LinkCache::singleton();
        $linkCache->clear();

        if ( is_null( $this->title ) ) {
            $this->error = "refreshLinks2: Invalid title";
            return false;
        }

        // Back compat for pre-r94435 jobs
        $table = isset( $this->params['table'] ) ? $this->params['table'] : 'templatelinks';

        // Avoid slave lag when fetching templates.
        // When the outermost job is run, we know that the caller that enqueued it must have
        // committed the relevant changes to the DB by now. At that point, record the master
        // position and pass it along as the job recursively breaks into smaller range jobs.
        // Hopefully, when leaf jobs are popped, the slaves will have reached that position.
        if ( isset( $this->params['masterPos'] ) ) {
            $masterPos = $this->params['masterPos'];
        } elseif ( wfGetLB()->getServerCount() > 1 ) {
            $masterPos = wfGetLB()->getMasterPos();
        } else {
            $masterPos = false;
        }

        $tbc = $this->title->getBacklinkCache();

        $jobs = array(); // jobs to insert
        if ( isset( $this->params['start'] ) && isset( $this->params['end'] ) ) {
            # This is a partition job to trigger the insertion of leaf jobs...
            $jobs = array_merge( $jobs, $this->getSingleTitleJobs( $table, $masterPos ) );
        } else {
            # This is a base job to trigger the insertion of partitioned jobs...
            if ( $tbc->getNumLinks( $table, $wgUpdateRowsPerJob + 1 ) <= $wgUpdateRowsPerJob ) {
                # Just directly insert the single per-title jobs
                $jobs = array_merge( $jobs, $this->getSingleTitleJobs( $table, $masterPos ) );
            } else {
                # Insert the partition jobs to make per-title jobs
                foreach ( $tbc->partition( $table, $wgUpdateRowsPerJob ) as $batch ) {
                    list( $start, $end ) = $batch;
                    $jobs[] = new RefreshLinksJob2( $this->title,
                        array(
                            'table' => $table,
                            'start' => $start,
                            'end' => $end,
                            'masterPos' => $masterPos,
                        ) + $this->getRootJobParams() // carry over information for de-duplication
                    );
                }
            }
        }

        if ( count( $jobs ) ) {
            JobQueueGroup::singleton()->push( $jobs );
        }

        return true;
    }

    protected function getSingleTitleJobs( $table, $masterPos ) {
        # The "start"/"end" fields are not set for the base jobs
        $start = isset( $this->params['start'] ) ? $this->params['start'] : false;
        $end = isset( $this->params['end'] ) ? $this->params['end'] : false;
        $titles = $this->title->getBacklinkCache()->getLinks( $table, $start, $end );
        # Convert into single page refresh links jobs.
        # This handles well when in sapi mode and is useful in any case for job
        # de-duplication. If many pages use template A, and that template itself
        # uses template B, then an edit to both will create many duplicate jobs.
        # Roughly speaking, for each page, one of the "RefreshLinksJob" jobs will
        # get run first, and when it does, it will remove the duplicates. Of course,
        # one page could have its job popped when the other page's job is still
        # buried within the logic of a refreshLinks2 job.
        $jobs = array();
        foreach ( $titles as $title ) {
            $jobs[] = new RefreshLinksJob( $title,
                array( 'masterPos' => $masterPos ) + $this->getRootJobParams()
            ); // carry over information for de-duplication
        }
        return $jobs;
    }

    public function getDeduplicationInfo() {
        $info = parent::getDeduplicationInfo();
        // Don't let highly unique "masterPos" values ruin duplicate detection
        if ( is_array( $info['params'] ) ) {
            unset( $info['params']['masterPos'] );
        }
        return $info;
    }
}