MediaWiki 1.7.1 wiederhergestellt

1 files changed, 230 insertions, 0 deletions

diff --git a/includes/HTMLCacheUpdate.php b/includes/HTMLCacheUpdate.php
new file mode 100644
index 00000000..47703b20
--- /dev/null
+++ b/includes/HTMLCacheUpdate.php
@@ -0,0 +1,230 @@
+<?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.
+ */
+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;
+	}
+
+	function doUpdate() {
+		# Fetch the IDs
+		$cond = $this->getToCondition();
+		$dbr =& wfGetDB( DB_SLAVE );
+		$res = $dbr->select( $this->mTable, $this->getFromField(), $cond, __METHOD__ );
+		$resWrap = new ResultWrapper( $dbr, $res );
+		if ( $dbr->numRows( $res ) != 0 ) {
+			if ( $dbr->numRows( $res ) > $this->mRowsPerJob ) {
+				$this->insertJobs( $resWrap );
+			} else {
+				$this->invalidateIDs( $resWrap );
+			}
+		}
+		$dbr->freeResult( $res );
+	}
+
+	function insertJobs( ResultWrapper $res ) {
+		$numRows = $res->numRows();
+		$numBatches = ceil( $numRows / $this->mRowsPerJob );
+		$realBatchSize = $numRows / $numBatches;
+		$boundaries = array();
+		$start = false;
+		$jobs = array();
+		do {
+			for ( $i = 0; $i < $realBatchSize - 1; $i++ ) {
+				$row = $res->fetchRow();
+				if ( $row ) {
+					$id = $row[0];
+				} else {
+					$id = false;
+					break;
+				}
+			}
+			if ( $id !== false ) {
+				// One less on the end to avoid duplicating the boundary
+				$job = new HTMLCacheUpdateJob( $this->mTitle, $this->mTable, $start, $id - 1 );
+			} else {
+				$job = new HTMLCacheUpdateJob( $this->mTitle, $this->mTable, $start, false );
+			}
+			$jobs[] = $job;
+
+			$start = $id;
+		} while ( $start );
+
+		Job::batchInsert( $jobs );
+	}
+
+	function getPrefix() {
+		static $prefixes = array(
+			'pagelinks' => 'pl',
+			'imagelinks' => 'il',
+			'categorylinks' => 'cl',
+			'templatelinks' => 'tl',
+			
+			# Not needed
+			# 'externallinks' => 'el',
+			# 'langlinks' => 'll'
+		);
+
+		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;
+	}
+	
+	function getFromField() {
+		return $this->getPrefix() . '_from';
+	}
+
+	function getToCondition() {
+		switch ( $this->mTable ) {
+			case 'pagelinks':
+				return array( 
+					'pl_namespace' => $this->mTitle->getNamespace(),
+					'pl_title' => $this->mTitle->getDBkey()
+				);
+			case 'templatelinks':
+				return array(
+					'tl_namespace' => $this->mTitle->getNamespace(),
+					'tl_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
+	 */
+	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 ) {
+						$cm = new CacheManager($title);
+						@unlink($cm->fileCacheName());
+					}
+				}
+			}
+		}
+	}
+}
+
+class HTMLCacheUpdateJob extends Job {
+	var $table, $start, $end;
+
+	/**
+	 * Construct a job
+	 * @param Title $title The title linked to
+	 * @param string $table The name of the link table.
+	 * @param integer $start Beginning page_id or false for open interval
+	 * @param integer $end End page_id or false for open interval
+	 * @param integer $id job_id
+	 */
+	function __construct( $title, $table, $start, $end, $id = 0 ) {
+		$params = array(
+			'table' => $table, 
+			'start' => $start, 
+			'end' => $end );
+		parent::__construct( 'htmlCacheUpdate', $title, $params, $id );
+		$this->table = $table;
+		$this->start = intval( $start );
+		$this->end = intval( $end );
+	}
+
+	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( new ResultWrapper( $dbr, $res ) );
+		$dbr->freeResult( $res );
+
+		return true;
+	}
+}
+?>