wikimedia/mediawiki-core

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maintenance/purgeChangedPages.php

Summary

Maintainability
B
6 hrs
Test Coverage
<?php
/**
 * Send purge requests for pages edited in date range to squid/varnish.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @ingroup Maintenance
 */

// @codeCoverageIgnoreStart
require_once __DIR__ . '/Maintenance.php';
// @codeCoverageIgnoreEnd

use MediaWiki\Title\Title;
use Wikimedia\Rdbms\IResultWrapper;

/**
 * Maintenance script that sends purge requests for pages edited in a date
 * range to squid/varnish.
 *
 * Can be used to recover from an HTCP message partition or other major cache
 * layer interruption.
 *
 * @ingroup Maintenance
 */
class PurgeChangedPages extends Maintenance {

    public function __construct() {
        parent::__construct();
        $this->addDescription( 'Send purge requests for edits in date range to squid/varnish' );
        $this->addOption( 'starttime', 'Starting timestamp', true, true );
        $this->addOption( 'endtime', 'Ending timestamp', true, true );
        $this->addOption( 'htcp-dest', 'HTCP announcement destination (IP:port)', false, true );
        $this->addOption( 'sleep-per-batch', 'Milliseconds to sleep between batches', false, true );
        $this->addOption( 'dry-run', 'Do not send purge requests' );
        $this->addOption( 'verbose', 'Show more output', false, false, 'v' );
        $this->setBatchSize( 100 );
    }

    public function execute() {
        global $wgHTCPRouting;

        if ( $this->hasOption( 'htcp-dest' ) ) {
            $parts = explode( ':', $this->getOption( 'htcp-dest' ), 2 );
            if ( count( $parts ) < 2 ) {
                // Add default htcp port
                $parts[] = '4827';
            }

            // Route all HTCP messages to provided host:port
            $wgHTCPRouting = [
                '' => [ 'host' => $parts[0], 'port' => $parts[1] ],
            ];
            if ( $this->hasOption( 'verbose' ) ) {
                $this->output( "HTCP broadcasts to {$parts[0]}:{$parts[1]}\n" );
            }
        }

        $dbr = $this->getReplicaDB();
        $minTime = $dbr->timestamp( $this->getOption( 'starttime' ) );
        $maxTime = $dbr->timestamp( $this->getOption( 'endtime' ) );

        if ( $maxTime < $minTime ) {
            $this->error( "\nERROR: starttime after endtime\n" );
            $this->maybeHelp( true );
        }

        $stuckCount = 0;
        while ( true ) {
            // Adjust bach size if we are stuck in a second that had many changes
            $bSize = ( $stuckCount + 1 ) * $this->getBatchSize();

            $res = $dbr->newSelectQueryBuilder()
                ->select( [ 'rev_timestamp', 'page_namespace', 'page_title', ] )
                ->from( 'revision' )
                ->join( 'page', null, 'rev_page=page_id' )
                ->where( [
                    $dbr->expr( 'rev_timestamp', '>', $minTime ),
                    $dbr->expr( 'rev_timestamp', '<=', $maxTime ),
                ] )
                // Only get rows where the revision is the latest for the page.
                // Other revisions would be duplicate and we don't need to purge if
                // there has been an edit after the interesting time window.
                ->andWhere( "page_latest = rev_id" )
                ->orderBy( 'rev_timestamp' )
                ->limit( $bSize )
                ->caller( __METHOD__ )->fetchResultSet();

            if ( !$res->numRows() ) {
                // nothing more found so we are done
                break;
            }

            // Kludge to not get stuck in loops for batches with the same timestamp
            [ $rows, $lastTime ] = $this->pageableSortedRows( $res, 'rev_timestamp', $bSize );
            if ( !count( $rows ) ) {
                ++$stuckCount;
                continue;
            }
            // Reset suck counter
            $stuckCount = 0;

            $this->output( "Processing changes from {$minTime} to {$lastTime}.\n" );

            // Advance past the last row next time
            $minTime = $lastTime;

            // Create list of URLs from page_namespace + page_title
            $urls = [];
            foreach ( $rows as $row ) {
                $title = Title::makeTitle( $row->page_namespace, $row->page_title );
                $urls[] = $title->getInternalURL();
            }

            if ( $this->hasOption( 'dry-run' ) || $this->hasOption( 'verbose' ) ) {
                $this->output( implode( "\n", $urls ) . "\n" );
                if ( $this->hasOption( 'dry-run' ) ) {
                    continue;
                }
            }

            // Send batch of purge requests out to CDN servers
            $hcu = $this->getServiceContainer()->getHtmlCacheUpdater();
            $hcu->purgeUrls( $urls, $hcu::PURGE_NAIVE );

            if ( $this->hasOption( 'sleep-per-batch' ) ) {
                // sleep-per-batch is milliseconds, usleep wants micro seconds.
                usleep( 1000 * (int)$this->getOption( 'sleep-per-batch' ) );
            }
        }

        $this->output( "Done!\n" );
    }

    /**
     * Remove all the rows in a result set with the highest value for column
     * $column unless the number of rows is less $limit. This returns the new
     * array of rows and the highest value of column $column for the rows left.
     * The ordering of rows is maintained.
     *
     * This is useful for paging on mostly-unique values that may sometimes
     * have large clumps of identical values. It should be safe to do the next
     * query on items with a value higher than the highest of the rows returned here.
     * If this returns an empty array for a non-empty query result, then all the rows
     * had the same column value and the query should be repeated with a higher LIMIT.
     *
     * @todo move this elsewhere
     *
     * @param IResultWrapper $res Query result sorted by $column (ascending)
     * @param string $column
     * @param int $limit
     * @return array (array of rows, string column value)
     */
    protected function pageableSortedRows( IResultWrapper $res, $column, $limit ) {
        $rows = iterator_to_array( $res, false );

        // Nothing to do
        if ( !$rows ) {
            return [ [], null ];
        }

        $lastValue = end( $rows )->$column;
        if ( count( $rows ) < $limit ) {
            return [ $rows, $lastValue ];
        }

        for ( $i = count( $rows ) - 1; $i >= 0; --$i ) {
            if ( $rows[$i]->$column !== $lastValue ) {
                break;
            }

            unset( $rows[$i] );
        }

        // No more rows left
        if ( !$rows ) {
            return [ [], null ];
        }

        return [ $rows, end( $rows )->$column ];
    }
}

// @codeCoverageIgnoreStart
$maintClass = PurgeChangedPages::class;
require_once RUN_MAINTENANCE_IF_MAIN;
// @codeCoverageIgnoreEnd