1 files changed, 20 insertions, 206 deletions

diff --git a/includes/cache/HTMLCacheUpdate.php b/includes/cache/HTMLCacheUpdate.php
index 0a3c0023..88e79281 100644
--- a/includes/cache/HTMLCacheUpdate.php
+++ b/includes/cache/HTMLCacheUpdate.php
@@ -23,24 +23,6 @@
 
 /**
  * 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
- * File::getLinksTo() and Title::touchArray(), which uses about 2KB of memory per
- * link.
  *
  * @ingroup Cache
  */
@@ -50,8 +32,7 @@ class HTMLCacheUpdate implements DeferrableUpdate {
 	 */
 	public $mTitle;
 
-	public $mTable, $mPrefix, $mStart, $mEnd;
-	public $mRowsPerJob, $mRowsPerQuery;
+	public $mTable;
 
 	/**
 	 * @param $titleTo
@@ -59,202 +40,35 @@ class HTMLCacheUpdate implements DeferrableUpdate {
 	 * @param $start bool
 	 * @param $end bool
 	 */
-	function __construct( $titleTo, $table, $start = false, $end = false ) {
-		global $wgUpdateRowsPerJob, $wgUpdateRowsPerQuery;
-
+	function __construct( Title $titleTo, $table ) {
 		$this->mTitle = $titleTo;
 		$this->mTable = $table;
-		$this->mStart = $start;
-		$this->mEnd = $end;
-		$this->mRowsPerJob = $wgUpdateRowsPerJob;
-		$this->mRowsPerQuery = $wgUpdateRowsPerQuery;
-		$this->mCache = $this->mTitle->getBacklinkCache();
 	}
 
 	public function doUpdate() {
-		if ( $this->mStart || $this->mEnd ) {
-			$this->doPartialUpdate();
-			return;
-		}
-
-		# Get an estimate of the number of rows from the BacklinkCache
-		$numRows = $this->mCache->getNumLinks( $this->mTable );
-		if ( $numRows > $this->mRowsPerJob * 2 ) {
-			# Do fast cached partition
-			$this->insertJobs();
-		} else {
-			# Get the links from the DB
-			$titleArray = $this->mCache->getLinks( $this->mTable );
-			# Check if the row count estimate was correct
-			if ( $titleArray->count() > $this->mRowsPerJob * 2 ) {
-				# Not correct, do accurate partition
-				wfDebug( __METHOD__.": row count estimate was incorrect, repartitioning\n" );
-				$this->insertJobsFromTitles( $titleArray );
-			} else {
-				$this->invalidateTitles( $titleArray );
-			}
-		}
-	}
-
-	/**
-	 * Update some of the backlinks, defined by a page ID range
-	 */
-	protected function doPartialUpdate() {
-		$titleArray = $this->mCache->getLinks( $this->mTable, $this->mStart, $this->mEnd );
-		if ( $titleArray->count() <= $this->mRowsPerJob * 2 ) {
-			# This partition is small enough, do the update
-			$this->invalidateTitles( $titleArray );
-		} else {
-			# Partitioning was excessively inaccurate. Divide the job further.
-			# This can occur when a large number of links are added in a short
-			# period of time, say by updating a heavily-used template.
-			$this->insertJobsFromTitles( $titleArray );
-		}
-	}
+		global $wgMaxBacklinksInvalidate;
 
-	/**
-	 * Partition the current range given by $this->mStart and $this->mEnd,
-	 * using a pre-calculated title array which gives the links in that range.
-	 * Queue the resulting jobs.
-	 *
-	 * @param $titleArray array
-	 */
-	protected function insertJobsFromTitles( $titleArray ) {
-		# We make subpartitions in the sense that the start of the first job
-		# will be the start of the parent partition, and the end of the last
-		# job will be the end of the parent partition.
-		$jobs = array();
-		$start = $this->mStart; # start of the current job
-		$numTitles = 0;
-		foreach ( $titleArray as $title ) {
-			$id = $title->getArticleID();
-			# $numTitles is now the number of titles in the current job not
-			# including the current ID
-			if ( $numTitles >= $this->mRowsPerJob ) {
-				# Add a job up to but not including the current ID
-				$params = array(
-					'table' => $this->mTable,
-					'start' => $start,
-					'end' => $id - 1
-				);
-				$jobs[] = new HTMLCacheUpdateJob( $this->mTitle, $params );
-				$start = $id;
-				$numTitles = 0;
-			}
-			$numTitles++;
-		}
-		# Last job
-		$params = array(
-			'table' => $this->mTable,
-			'start' => $start,
-			'end' => $this->mEnd
-		);
-		$jobs[] = new HTMLCacheUpdateJob( $this->mTitle, $params );
-		wfDebug( __METHOD__.": repartitioning into " . count( $jobs ) . " jobs\n" );
-
-		if ( count( $jobs ) < 2 ) {
-			# I don't think this is possible at present, but handling this case
-			# makes the code a bit more robust against future code updates and
-			# avoids a potential infinite loop of repartitioning
-			wfDebug( __METHOD__.": repartitioning failed!\n" );
-			$this->invalidateTitles( $titleArray );
-			return;
-		}
+		wfProfileIn( __METHOD__ );
 
-		Job::batchInsert( $jobs );
-	}
-
-	/**
-	 * @return mixed
-	 */
-	protected function insertJobs() {
-		$batches = $this->mCache->partition( $this->mTable, $this->mRowsPerJob );
-		if ( !$batches ) {
-			return;
-		}
-		$jobs = array();
-		foreach ( $batches as $batch ) {
-			$params = array(
+		$job = new HTMLCacheUpdateJob(
+			$this->mTitle,
+			array(
 				'table' => $this->mTable,
-				'start' => $batch[0],
-				'end' => $batch[1],
-			);
-			$jobs[] = new HTMLCacheUpdateJob( $this->mTitle, $params );
-		}
-		Job::batchInsert( $jobs );
-	}
-
-	/**
-	 * Invalidate an array (or iterator) of Title objects, right now
-	 * @param $titleArray array
-	 */
-	protected function invalidateTitles( $titleArray ) {
-		global $wgUseFileCache, $wgUseSquid;
-
-		$dbw = wfGetDB( DB_MASTER );
-		$timestamp = $dbw->timestamp();
-
-		# Get all IDs in this query into an array
-		$ids = array();
-		foreach ( $titleArray as $title ) {
-			$ids[] = $title->getArticleID();
-		}
-
-		if ( !$ids ) {
-			return;
-		}
-
-		# Update page_touched
-		$batches = array_chunk( $ids, $this->mRowsPerQuery );
-		foreach ( $batches as $batch ) {
-			$dbw->update( 'page',
-				array( 'page_touched' => $timestamp ),
-				array( 'page_id' => $batch ),
-				__METHOD__
-			);
-		}
-
-		# Update squid
-		if ( $wgUseSquid ) {
-			$u = SquidUpdate::newFromTitles( $titleArray );
-			$u->doUpdate();
-		}
+			) + Job::newRootJobParams( // "overall" refresh links job info
+				"htmlCacheUpdate:{$this->mTable}:{$this->mTitle->getPrefixedText()}"
+			)
+		);
 
-		# Update file cache
-		if  ( $wgUseFileCache ) {
-			foreach ( $titleArray as $title ) {
-				HTMLFileCache::clearFileCache( $title );
-			}
+		$count = $this->mTitle->getBacklinkCache()->getNumLinks( $this->mTable, 200 );
+		if ( $wgMaxBacklinksInvalidate !== false && $count > $wgMaxBacklinksInvalidate ) {
+			wfDebug( "Skipped HTML cache invalidation of {$this->mTitle->getPrefixedText()}." );
+		} elseif ( $count >= 200 ) { // many backlinks
+			JobQueueGroup::singleton()->push( $job );
+			JobQueueGroup::singleton()->deduplicateRootJob( $job );
+		} else { // few backlinks ($count might be off even if 0)
+			$job->run(); // just do the purge query now
 		}
-	}
-}
-
-
-/**
- * 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 $params Array: job parameters (table, start and end page_ids)
-	 * @param $id Integer: 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, $this->start, $this->end );
-		$update->doUpdate();
-		return true;
+		wfProfileOut( __METHOD__ );
 	}
 }