+++ /dev/null
-<?php
-
-/**
- * Class to invalidate the HTML cache of all the pages linking to a given title.
- * Small numbers of links will be done immediately, large numbers are pushed onto
- * the job queue.
- *
- * This class is designed to work efficiently with small numbers of links, and
- * to work reasonably well with up to ~10^5 links. Above ~10^6 links, the memory
- * and time requirements of loading all backlinked IDs in doUpdate() might become
- * prohibitive. The requirements measured at Wikimedia are approximately:
- *
- * memory: 48 bytes per row
- * time: 16us per row for the query plus processing
- *
- * The reason this query is done is to support partitioning of the job
- * by backlinked ID. The memory issue could be allieviated by doing this query in
- * batches, but of course LIMIT with an offset is inefficient on the DB side.
- *
- * The class is nevertheless a vast improvement on the previous method of using
- * Image::getLinksTo() and Title::touchArray(), which uses about 2KB of memory per
- * link.
- *
- * @ingroup Cache
- */
-class HTMLCacheUpdate
-{
- public $mTitle, $mTable, $mPrefix;
- public $mRowsPerJob, $mRowsPerQuery;
-
- function __construct( $titleTo, $table ) {
- global $wgUpdateRowsPerJob, $wgUpdateRowsPerQuery;
-
- $this->mTitle = $titleTo;
- $this->mTable = $table;
- $this->mRowsPerJob = $wgUpdateRowsPerJob;
- $this->mRowsPerQuery = $wgUpdateRowsPerQuery;
- }
-
- public function doUpdate() {
- # Fetch the IDs
- $cond = $this->getToCondition();
- $dbr = wfGetDB( DB_SLAVE );
- $res = $dbr->select( $this->mTable, $this->getFromField(), $cond, __METHOD__ );
-
- if ( $dbr->numRows( $res ) != 0 ) {
- if ( $dbr->numRows( $res ) > $this->mRowsPerJob ) {
- $this->insertJobs( $res );
- } else {
- $this->invalidateIDs( $res );
- }
- }
- wfRunHooks( 'HTMLCacheUpdate::doUpdate', array($this->mTitle) );
- }
-
- protected function insertJobs( ResultWrapper $res ) {
- $numRows = $res->numRows();
- $numBatches = ceil( $numRows / $this->mRowsPerJob );
- $realBatchSize = $numRows / $numBatches;
- $start = false;
- $jobs = array();
- do {
- for ( $i = 0; $i <= $realBatchSize - 1; $i++ ) {
- $row = $res->fetchRow();
- if ( $row ) {
- $id = $row[0];
- } else {
- $id = false;
- break;
- }
- }
-
- $params = array(
- 'table' => $this->mTable,
- 'start' => $start,
- 'end' => ( $id !== false ? $id - 1 : false ),
- );
- $jobs[] = new HTMLCacheUpdateJob( $this->mTitle, $params );
-
- $start = $id;
- } while ( $start );
-
- Job::batchInsert( $jobs );
- }
-
- protected function getPrefix() {
- static $prefixes = array(
- 'pagelinks' => 'pl',
- 'imagelinks' => 'il',
- 'categorylinks' => 'cl',
- 'templatelinks' => 'tl',
- 'redirect' => 'rd',
- );
-
- if ( is_null( $this->mPrefix ) ) {
- $this->mPrefix = $prefixes[$this->mTable];
- if ( is_null( $this->mPrefix ) ) {
- throw new MWException( "Invalid table type \"{$this->mTable}\" in " . __CLASS__ );
- }
- }
- return $this->mPrefix;
- }
-
- public function getFromField() {
- return $this->getPrefix() . '_from';
- }
-
- public function getToCondition() {
- $prefix = $this->getPrefix();
- switch ( $this->mTable ) {
- case 'pagelinks':
- case 'templatelinks':
- case 'redirect':
- return array(
- "{$prefix}_namespace" => $this->mTitle->getNamespace(),
- "{$prefix}_title" => $this->mTitle->getDBkey()
- );
- case 'imagelinks':
- return array( 'il_to' => $this->mTitle->getDBkey() );
- case 'categorylinks':
- return array( 'cl_to' => $this->mTitle->getDBkey() );
- }
- throw new MWException( 'Invalid table type in ' . __CLASS__ );
- }
-
- /**
- * Invalidate a set of IDs, right now
- */
- public function invalidateIDs( ResultWrapper $res ) {
- global $wgUseFileCache, $wgUseSquid;
-
- if ( $res->numRows() == 0 ) {
- return;
- }
-
- $dbw = wfGetDB( DB_MASTER );
- $timestamp = $dbw->timestamp();
- $done = false;
-
- while ( !$done ) {
- # Get all IDs in this query into an array
- $ids = array();
- for ( $i = 0; $i < $this->mRowsPerQuery; $i++ ) {
- $row = $res->fetchRow();
- if ( $row ) {
- $ids[] = $row[0];
- } else {
- $done = true;
- break;
- }
- }
-
- if ( !count( $ids ) ) {
- break;
- }
-
- # Update page_touched
- $dbw->update( 'page',
- array( 'page_touched' => $timestamp ),
- array( 'page_id IN (' . $dbw->makeList( $ids ) . ')' ),
- __METHOD__
- );
-
- # Update squid
- if ( $wgUseSquid || $wgUseFileCache ) {
- $titles = Title::newFromIDs( $ids );
- if ( $wgUseSquid ) {
- $u = SquidUpdate::newFromTitles( $titles );
- $u->doUpdate();
- }
-
- # Update file cache
- if ( $wgUseFileCache ) {
- foreach ( $titles as $title ) {
- HTMLFileCache::clearFileCache( $title );
- }
- }
- }
- }
- }
-}
-
-/**
- * Job wrapper for HTMLCacheUpdate. Gets run whenever a related
- * job gets called from the queue.
- *
- * @ingroup JobQueue
- */
-class HTMLCacheUpdateJob extends Job {
- var $table, $start, $end;
-
- /**
- * Construct a job
- * @param Title $title The title linked to
- * @param array $params Job parameters (table, start and end page_ids)
- * @param integer $id job_id
- */
- function __construct( $title, $params, $id = 0 ) {
- parent::__construct( 'htmlCacheUpdate', $title, $params, $id );
- $this->table = $params['table'];
- $this->start = $params['start'];
- $this->end = $params['end'];
- }
-
- public function run() {
- $update = new HTMLCacheUpdate( $this->title, $this->table );
-
- $fromField = $update->getFromField();
- $conds = $update->getToCondition();
- if ( $this->start ) {
- $conds[] = "$fromField >= {$this->start}";
- }
- if ( $this->end ) {
- $conds[] = "$fromField <= {$this->end}";
- }
-
- $dbr = wfGetDB( DB_SLAVE );
- $res = $dbr->select( $this->table, $fromField, $conds, __METHOD__ );
- $update->invalidateIDs( $res );
-
- return true;
- }
-}
scripts.mit.edu / autoinstallsdev / mediawiki.git / blobdiff