Update to MediaWiki 1.21.1

13 files changed, 1907 insertions, 415 deletions

diff --git a/includes/cache/BacklinkCache.php b/includes/cache/BacklinkCache.php
new file mode 100644
index 00000000..a59cc9a2
--- /dev/null
+++ b/includes/cache/BacklinkCache.php
@@ -0,0 +1,452 @@
+<?php
+/**
+ * Class for fetching backlink lists, approximate backlink counts and
+ * partitions.
+ *
+ * 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
+ * @author Tim Starling
+ * @copyright © 2009, Tim Starling, Domas Mituzas
+ * @copyright © 2010, Max Sem
+ * @copyright © 2011, Antoine Musso
+ */
+
+/**
+ * Class for fetching backlink lists, approximate backlink counts and
+ * partitions. This is a shared cache.
+ *
+ * Instances of this class should typically be fetched with the method
+ * $title->getBacklinkCache().
+ *
+ * Ideally you should only get your backlinks from here when you think
+ * there is some advantage in caching them. Otherwise it's just a waste
+ * of memory.
+ *
+ * Introduced by r47317
+ *
+ * @internal documentation reviewed on 18 Mar 2011 by hashar
+ */
+class BacklinkCache {
+	/** @var ProcessCacheLRU */
+	protected static $cache;
+
+	/**
+	 * Multi dimensions array representing batches. Keys are:
+	 *  > (string) links table name
+	 *    > 'numRows' : Number of rows for this link table
+	 *    > 'batches' : array( $start, $end )
+	 *
+	 * @see BacklinkCache::partitionResult()
+	 *
+	 * Cleared with BacklinkCache::clear()
+	 */
+	protected $partitionCache = array();
+
+	/**
+	 * Contains the whole links from a database result.
+	 * This is raw data that will be partitioned in $partitionCache
+	 *
+	 * Initialized with BacklinkCache::getLinks()
+	 * Cleared with BacklinkCache::clear()
+	 */
+	protected $fullResultCache = array();
+
+	/**
+	 * Local copy of a database object.
+	 *
+	 * Accessor: BacklinkCache::getDB()
+	 * Mutator : BacklinkCache::setDB()
+	 * Cleared with BacklinkCache::clear()
+	 */
+	protected $db;
+
+	/**
+	 * Local copy of a Title object
+	 */
+	protected $title;
+
+	const CACHE_EXPIRY = 3600;
+
+	/**
+	 * Create a new BacklinkCache
+	 *
+	 * @param Title $title : Title object to create a backlink cache for
+	 */
+	public function __construct( Title $title ) {
+		$this->title = $title;
+	}
+
+	/**
+	 * Create a new BacklinkCache or reuse any existing one.
+	 * Currently, only one cache instance can exist; callers that
+	 * need multiple backlink cache objects should keep them in scope.
+	 *
+	 * @param Title $title : Title object to get a backlink cache for
+	 * @return BacklinkCache
+	 */
+	public static function get( Title $title ) {
+		if ( !self::$cache ) { // init cache
+			self::$cache = new ProcessCacheLRU( 1 );
+		}
+		$dbKey = $title->getPrefixedDBkey();
+		if ( !self::$cache->has( $dbKey, 'obj' ) ) {
+			self::$cache->set( $dbKey, 'obj', new self( $title ) );
+		}
+		return self::$cache->get( $dbKey, 'obj' );
+	}
+
+	/**
+	 * Serialization handler, diasallows to serialize the database to prevent
+	 * failures after this class is deserialized from cache with dead DB
+	 * connection.
+	 *
+	 * @return array
+	 */
+	function __sleep() {
+		return array( 'partitionCache', 'fullResultCache', 'title' );
+	}
+
+	/**
+	 * Clear locally stored data and database object.
+	 */
+	public function clear() {
+		$this->partitionCache = array();
+		$this->fullResultCache = array();
+		unset( $this->db );
+	}
+
+	/**
+	 * Set the Database object to use
+	 *
+	 * @param $db DatabaseBase
+	 */
+	public function setDB( $db ) {
+		$this->db = $db;
+	}
+
+	/**
+	 * Get the slave connection to the database
+	 * When non existing, will initialize the connection.
+	 * @return DatabaseBase object
+	 */
+	protected function getDB() {
+		if ( !isset( $this->db ) ) {
+			$this->db = wfGetDB( DB_SLAVE );
+		}
+
+		return $this->db;
+	}
+
+	/**
+	 * Get the backlinks for a given table. Cached in process memory only.
+	 * @param $table String
+	 * @param $startId Integer or false
+	 * @param $endId Integer or false
+	 * @return TitleArrayFromResult
+	 */
+	public function getLinks( $table, $startId = false, $endId = false ) {
+		wfProfileIn( __METHOD__ );
+
+		$fromField = $this->getPrefix( $table ) . '_from';
+
+		if ( $startId || $endId ) {
+			// Partial range, not cached
+			wfDebug( __METHOD__ . ": from DB (uncacheable range)\n" );
+			$conds = $this->getConditions( $table );
+
+			// Use the from field in the condition rather than the joined page_id,
+			// because databases are stupid and don't necessarily propagate indexes.
+			if ( $startId ) {
+				$conds[] = "$fromField >= " . intval( $startId );
+			}
+
+			if ( $endId ) {
+				$conds[] = "$fromField <= " . intval( $endId );
+			}
+
+			$res = $this->getDB()->select(
+				array( $table, 'page' ),
+				array( 'page_namespace', 'page_title', 'page_id' ),
+				$conds,
+				__METHOD__,
+				array(
+					'STRAIGHT_JOIN',
+					'ORDER BY' => $fromField
+				) );
+			$ta = TitleArray::newFromResult( $res );
+
+			wfProfileOut( __METHOD__ );
+			return $ta;
+		}
+
+		// @todo FIXME: Make this a function?
+		if ( !isset( $this->fullResultCache[$table] ) ) {
+			wfDebug( __METHOD__ . ": from DB\n" );
+			$res = $this->getDB()->select(
+				array( $table, 'page' ),
+				array( 'page_namespace', 'page_title', 'page_id' ),
+				$this->getConditions( $table ),
+				__METHOD__,
+				array(
+					'STRAIGHT_JOIN',
+					'ORDER BY' => $fromField,
+				) );
+			$this->fullResultCache[$table] = $res;
+		}
+
+		$ta = TitleArray::newFromResult( $this->fullResultCache[$table] );
+
+		wfProfileOut( __METHOD__ );
+		return $ta;
+	}
+
+	/**
+	 * Get the field name prefix for a given table
+	 * @param $table String
+	 * @throws MWException
+	 * @return null|string
+	 */
+	protected function getPrefix( $table ) {
+		static $prefixes = array(
+			'pagelinks' => 'pl',
+			'imagelinks' => 'il',
+			'categorylinks' => 'cl',
+			'templatelinks' => 'tl',
+			'redirect' => 'rd',
+		);
+
+		if ( isset( $prefixes[$table] ) ) {
+			return $prefixes[$table];
+		} else {
+			$prefix = null;
+			wfRunHooks( 'BacklinkCacheGetPrefix', array( $table, &$prefix ) );
+			if( $prefix ) {
+				return $prefix;
+			} else {
+				throw new MWException( "Invalid table \"$table\" in " . __CLASS__ );
+			}
+		}
+	}
+
+	/**
+	 * Get the SQL condition array for selecting backlinks, with a join
+	 * on the page table.
+	 * @param $table String
+	 * @throws MWException
+	 * @return array|null
+	 */
+	protected function getConditions( $table ) {
+		$prefix = $this->getPrefix( $table );
+
+		// @todo FIXME: imagelinks and categorylinks do not rely on getNamespace,
+		// they could be moved up for nicer case statements
+		switch ( $table ) {
+			case 'pagelinks':
+			case 'templatelinks':
+				$conds = array(
+					"{$prefix}_namespace" => $this->title->getNamespace(),
+					"{$prefix}_title" => $this->title->getDBkey(),
+					"page_id={$prefix}_from"
+				);
+				break;
+			case 'redirect':
+				$conds = array(
+					"{$prefix}_namespace" => $this->title->getNamespace(),
+					"{$prefix}_title" => $this->title->getDBkey(),
+					$this->getDb()->makeList( array(
+						"{$prefix}_interwiki" => '',
+						"{$prefix}_interwiki IS NULL",
+					), LIST_OR ),
+					"page_id={$prefix}_from"
+				);
+				break;
+			case 'imagelinks':
+				$conds = array(
+					'il_to' => $this->title->getDBkey(),
+					'page_id=il_from'
+				);
+				break;
+			case 'categorylinks':
+				$conds = array(
+					'cl_to' => $this->title->getDBkey(),
+					'page_id=cl_from',
+				);
+				break;
+			default:
+				$conds = null;
+				wfRunHooks( 'BacklinkCacheGetConditions', array( $table, $this->title, &$conds ) );
+				if( !$conds ) {
+					throw new MWException( "Invalid table \"$table\" in " . __CLASS__ );
+				}
+		}
+
+		return $conds;
+	}
+
+	/**
+	 * Check if there are any backlinks
+	 * @param $table String
+	 * @return bool
+	 */
+	public function hasLinks( $table ) {
+		return ( $this->getNumLinks( $table, 1 ) > 0 );
+	}
+
+	/**
+	 * Get the approximate number of backlinks
+	 * @param $table String
+	 * @param $max integer Only count up to this many backlinks
+	 * @return integer
+	 */
+	public function getNumLinks( $table, $max = INF ) {
+		global $wgMemc;
+
+		// 1) try partition cache ...
+		if ( isset( $this->partitionCache[$table] ) ) {
+			$entry = reset( $this->partitionCache[$table] );
+			return min( $max, $entry['numRows'] );
+		}
+
+		// 2) ... then try full result cache ...
+		if ( isset( $this->fullResultCache[$table] ) ) {
+			return min( $max, $this->fullResultCache[$table]->numRows() );
+		}
+
+		$memcKey = wfMemcKey( 'numbacklinks', md5( $this->title->getPrefixedDBkey() ), $table );
+
+		// 3) ... fallback to memcached ...
+		$count = $wgMemc->get( $memcKey );
+		if ( $count ) {
+			return min( $max, $count );
+		}
+
+		// 4) fetch from the database ...
+		if ( is_infinite( $max ) ) { // full count
+			$count = $this->getLinks( $table )->count();
+			$wgMemc->set( $memcKey, $count, self::CACHE_EXPIRY );
+		} else { // with limit
+			$count = $this->getDB()->select(
+				array( $table, 'page' ),
+				'1',
+				$this->getConditions( $table ),
+				__METHOD__,
+				array( 'LIMIT' => $max )
+			)->numRows();
+		}
+
+		return $count;
+	}
+
+	/**
+	 * Partition the backlinks into batches.
+	 * Returns an array giving the start and end of each range. The first
+	 * batch has a start of false, and the last batch has an end of false.
+	 *
+	 * @param string $table the links table name
+	 * @param $batchSize Integer
+	 * @return Array
+	 */
+	public function partition( $table, $batchSize ) {
+		global $wgMemc;
+
+		// 1) try partition cache ...
+		if ( isset( $this->partitionCache[$table][$batchSize] ) ) {
+			wfDebug( __METHOD__ . ": got from partition cache\n" );
+			return $this->partitionCache[$table][$batchSize]['batches'];
+		}
+
+		$this->partitionCache[$table][$batchSize] = false;
+		$cacheEntry =& $this->partitionCache[$table][$batchSize];
+
+		// 2) ... then try full result cache ...
+		if ( isset( $this->fullResultCache[$table] ) ) {
+			$cacheEntry = $this->partitionResult( $this->fullResultCache[$table], $batchSize );
+			wfDebug( __METHOD__ . ": got from full result cache\n" );
+			return $cacheEntry['batches'];
+		}
+
+		$memcKey = wfMemcKey(
+			'backlinks',
+			md5( $this->title->getPrefixedDBkey() ),
+			$table,
+			$batchSize
+		);
+
+		// 3) ... fallback to memcached ...
+		$memcValue = $wgMemc->get( $memcKey );
+		if ( is_array( $memcValue ) ) {
+			$cacheEntry = $memcValue;
+			wfDebug( __METHOD__ . ": got from memcached $memcKey\n" );
+			return $cacheEntry['batches'];
+		}
+
+		// 4) ... finally fetch from the slow database :(
+		$this->getLinks( $table );
+		$cacheEntry = $this->partitionResult( $this->fullResultCache[$table], $batchSize );
+		// Save partitions to memcached
+		$wgMemc->set( $memcKey, $cacheEntry, self::CACHE_EXPIRY );
+
+		// Save backlink count to memcached
+		$memcKey = wfMemcKey( 'numbacklinks', md5( $this->title->getPrefixedDBkey() ), $table );
+		$wgMemc->set( $memcKey, $cacheEntry['numRows'], self::CACHE_EXPIRY );
+
+		wfDebug( __METHOD__ . ": got from database\n" );
+		return $cacheEntry['batches'];
+	}
+
+	/**
+	 * Partition a DB result with backlinks in it into batches
+	 * @param $res ResultWrapper database result
+	 * @param $batchSize integer
+	 * @throws MWException
+	 * @return array @see
+	 */
+	protected function partitionResult( $res, $batchSize ) {
+		$batches = array();
+		$numRows = $res->numRows();
+		$numBatches = ceil( $numRows / $batchSize );
+
+		for ( $i = 0; $i < $numBatches; $i++ ) {
+			if ( $i == 0  ) {
+				$start = false;
+			} else {
+				$rowNum = intval( $numRows * $i / $numBatches );
+				$res->seek( $rowNum );
+				$row = $res->fetchObject();
+				$start = $row->page_id;
+			}
+
+			if ( $i == $numBatches - 1 ) {
+				$end = false;
+			} else {
+				$rowNum = intval( $numRows * ( $i + 1 ) / $numBatches );
+				$res->seek( $rowNum );
+				$row = $res->fetchObject();
+				$end = $row->page_id - 1;
+			}
+
+			# Sanity check order
+			if ( $start && $end && $start > $end ) {
+				throw new MWException( __METHOD__ . ': Internal error: query result out of order' );
+			}
+
+			$batches[] = array( $start, $end );
+		}
+
+		return array( 'numRows' => $numRows, 'batches' => $batches );
+	}
+}
diff --git a/includes/cache/CacheDependency.php b/includes/cache/CacheDependency.php
index a3c2b52a..0f047e80 100644
--- a/includes/cache/CacheDependency.php
+++ b/includes/cache/CacheDependency.php
@@ -74,7 +74,7 @@ class DependencyWrapper {
 
 	/**
 	 * Get the user-defined value
-	 * @return bool|\Mixed
+	 * @return bool|Mixed
 	 */
 	function getValue() {
 		return $this->value;
@@ -98,11 +98,11 @@ class DependencyWrapper {
 	 * calculated value will be stored to the cache in a wrapper.
 	 *
 	 * @param $cache BagOStuff a cache object such as $wgMemc
-	 * @param $key String: the cache key
+	 * @param string $key the cache key
 	 * @param $expiry Integer: the expiry timestamp or interval in seconds
 	 * @param $callback Mixed: the callback for generating the value, or false
-	 * @param $callbackParams Array: the function parameters for the callback
-	 * @param $deps Array: the dependencies to store on a cache miss. Note: these
+	 * @param array $callbackParams the function parameters for the callback
+	 * @param array $deps the dependencies to store on a cache miss. Note: these
 	 *    are not the dependencies used on a cache hit! Cache hits use the stored
 	 *    dependency array.
 	 *
@@ -153,7 +153,7 @@ class FileDependency extends CacheDependency {
 	/**
 	 * Create a file dependency
 	 *
-	 * @param $filename String: the name of the file, preferably fully qualified
+	 * @param string $filename the name of the file, preferably fully qualified
 	 * @param $timestamp Mixed: the unix last modified timestamp, or false if the
 	 *        file does not exist. If omitted, the timestamp will be loaded from
 	 *        the file.
@@ -404,7 +404,7 @@ class GlobalDependency extends CacheDependency {
 	 * @return bool
 	 */
 	function isExpired() {
-		if( !isset($GLOBALS[$this->name]) ) {
+		if( !isset( $GLOBALS[$this->name] ) ) {
 			return true;
 		}
 		return $GLOBALS[$this->name] != $this->value;
diff --git a/includes/cache/FileCacheBase.php b/includes/cache/FileCacheBase.php
index c0c5609c..30a72174 100644
--- a/includes/cache/FileCacheBase.php
+++ b/includes/cache/FileCacheBase.php
@@ -107,7 +107,7 @@ abstract class FileCacheBase {
 
 	/**
 	 * Check if up to date cache file exists
-	 * @param $timestamp string MW_TS timestamp
+	 * @param string $timestamp MW_TS timestamp
 	 *
 	 * @return bool
 	 */
@@ -163,7 +163,7 @@ abstract class FileCacheBase {
 
 		$this->checkCacheDirs(); // build parent dir
 		if ( !file_put_contents( $this->cachePath(), $text, LOCK_EX ) ) {
-			wfDebug( __METHOD__ . "() failed saving ". $this->cachePath() . "\n");
+			wfDebug( __METHOD__ . "() failed saving ". $this->cachePath() . "\n" );
 			$this->mCached = null;
 			return false;
 		}
@@ -229,7 +229,7 @@ abstract class FileCacheBase {
 	public function incrMissesRecent( WebRequest $request ) {
 		global $wgMemc;
 		if ( mt_rand( 0, self::MISS_FACTOR - 1 ) == 0 ) {
-			# Get a large IP range that should include the user  even if that 
+			# Get a large IP range that should include the user  even if that
 			# person's IP address changes
 			$ip = $request->getIP();
 			if ( !IP::isValid( $ip ) ) {
diff --git a/includes/cache/GenderCache.php b/includes/cache/GenderCache.php
index 2a169bb3..63e4226d 100644
--- a/includes/cache/GenderCache.php
+++ b/includes/cache/GenderCache.php
@@ -59,8 +59,8 @@ class GenderCache {
 
 	/**
 	 * Returns the gender for given username.
-	 * @param $username String or User: username
-	 * @param $caller String: the calling method
+	 * @param string $username or User: username
+	 * @param string $caller the calling method
 	 * @return String
 	 */
 	public function getGenderOf( $username, $caller = '' ) {
@@ -116,7 +116,7 @@ class GenderCache {
 	 *
 	 * @since 1.20
 	 * @param $titles List: array of Title objects or strings
-	 * @param $caller String: the calling method
+	 * @param string $caller the calling method
 	 */
 	public function doTitlesArray( $titles, $caller = '' ) {
 		$users = array();
@@ -137,7 +137,7 @@ class GenderCache {
 	/**
 	 * Preloads genders for given list of users.
 	 * @param $users List|String: usernames
-	 * @param $caller String: the calling method
+	 * @param string $caller the calling method
 	 */
 	public function doQuery( $users, $caller = '' ) {
 		$default = $this->getDefault();
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__ );
 	}
 }
diff --git a/includes/cache/HTMLFileCache.php b/includes/cache/HTMLFileCache.php
index 6bfeed32..055fd685 100644
--- a/includes/cache/HTMLFileCache.php
+++ b/includes/cache/HTMLFileCache.php
@@ -33,6 +33,7 @@ class HTMLFileCache extends FileCacheBase {
 	 * Construct an ObjectFileCache from a Title and an action
 	 * @param $title Title|string Title object or prefixed DB key string
 	 * @param $action string
+	 * @throws MWException
 	 * @return HTMLFileCache
 	 */
 	public static function newFromTitle( $title, $action ) {
@@ -127,7 +128,7 @@ class HTMLFileCache extends FileCacheBase {
 	public function loadFromFileCache( IContextSource $context ) {
 		global $wgMimeType, $wgLanguageCode;
 
-		wfDebug( __METHOD__ . "()\n");
+		wfDebug( __METHOD__ . "()\n" );
 		$filename = $this->cachePath();
 
 		$context->getOutput()->sendCacheControl();
@@ -167,10 +168,10 @@ class HTMLFileCache extends FileCacheBase {
 		$now = wfTimestampNow();
 		if ( $this->useGzip() ) {
 			$text = str_replace(
-				'</html>', '<!-- Cached/compressed '.$now." -->\n</html>", $text );
+				'</html>', '<!-- Cached/compressed ' . $now . " -->\n</html>", $text );
 		} else {
 			$text = str_replace(
-				'</html>', '<!-- Cached '.$now." -->\n</html>", $text );
+				'</html>', '<!-- Cached ' . $now . " -->\n</html>", $text );
 		}
 
 		// Store text to FS...
diff --git a/includes/cache/LinkBatch.php b/includes/cache/LinkBatch.php
index 372f983b..72a2e8e5 100644
--- a/includes/cache/LinkBatch.php
+++ b/includes/cache/LinkBatch.php
@@ -223,7 +223,7 @@ class LinkBatch {
 	/**
 	 * Construct a WHERE clause which will match all the given titles.
 	 *
-	 * @param $prefix String: the appropriate table's field name prefix ('page', 'pl', etc)
+	 * @param string $prefix the appropriate table's field name prefix ('page', 'pl', etc)
 	 * @param $db DatabaseBase object to use
 	 * @return mixed string with SQL where clause fragment, or false if no items.
 	 */
diff --git a/includes/cache/LinkCache.php b/includes/cache/LinkCache.php
index f759c020..0e41e265 100644
--- a/includes/cache/LinkCache.php
+++ b/includes/cache/LinkCache.php
@@ -74,11 +74,11 @@ class LinkCache {
 	 * Get a field of a title object from cache.
 	 * If this link is not good, it will return NULL.
 	 * @param $title Title
-	 * @param $field String: ('length','redirect','revision')
+	 * @param string $field ('length','redirect','revision','model')
 	 * @return mixed
 	 */
 	public function getGoodLinkFieldObj( $title, $field ) {
-		$dbkey = $title->getPrefixedDbKey();
+		$dbkey = $title->getPrefixedDBkey();
 		if ( array_key_exists( $dbkey, $this->mGoodLinkFields ) ) {
 			return $this->mGoodLinkFields[$dbkey][$field];
 		} else {
@@ -102,14 +102,16 @@ class LinkCache {
 	 * @param $len Integer: text's length
 	 * @param $redir Integer: whether the page is a redirect
 	 * @param $revision Integer: latest revision's ID
+	 * @param $model Integer: latest revision's content model ID
 	 */
-	public function addGoodLinkObj( $id, $title, $len = -1, $redir = null, $revision = false ) {
-		$dbkey = $title->getPrefixedDbKey();
+	public function addGoodLinkObj( $id, $title, $len = -1, $redir = null, $revision = false, $model = false ) {
+		$dbkey = $title->getPrefixedDBkey();
 		$this->mGoodLinks[$dbkey] = intval( $id );
 		$this->mGoodLinkFields[$dbkey] = array(
 			'length' => intval( $len ),
 			'redirect' => intval( $redir ),
-			'revision' => intval( $revision ) );
+			'revision' => intval( $revision ),
+			'model' => intval( $model ) );
 	}
 
 	/**
@@ -117,15 +119,16 @@ class LinkCache {
 	 * @since 1.19
 	 * @param $title Title
 	 * @param $row object which has the fields page_id, page_is_redirect,
-	 *  page_latest
+	 *  page_latest and page_content_model
 	 */
 	public function addGoodLinkObjFromRow( $title, $row ) {
-		$dbkey = $title->getPrefixedDbKey();
+		$dbkey = $title->getPrefixedDBkey();
 		$this->mGoodLinks[$dbkey] = intval( $row->page_id );
 		$this->mGoodLinkFields[$dbkey] = array(
 			'length' => intval( $row->page_len ),
 			'redirect' => intval( $row->page_is_redirect ),
 			'revision' => intval( $row->page_latest ),
+			'model' => !empty( $row->page_content_model ) ? strval( $row->page_content_model ) : null,
 		);
 	}
 
@@ -133,7 +136,7 @@ class LinkCache {
 	 * @param $title Title
 	 */
 	public function addBadLinkObj( $title ) {
-		$dbkey = $title->getPrefixedDbKey();
+		$dbkey = $title->getPrefixedDBkey();
 		if ( !$this->isBadLink( $dbkey ) ) {
 			$this->mBadLinks[$dbkey] = 1;
 		}
@@ -147,7 +150,7 @@ class LinkCache {
 	 * @param $title Title
 	 */
 	public function clearLink( $title ) {
-		$dbkey = $title->getPrefixedDbKey();
+		$dbkey = $title->getPrefixedDBkey();
 		unset( $this->mBadLinks[$dbkey] );
 		unset( $this->mGoodLinks[$dbkey] );
 		unset( $this->mGoodLinkFields[$dbkey] );
@@ -159,7 +162,7 @@ class LinkCache {
 	/**
 	 * Add a title to the link cache, return the page_id or zero if non-existent
 	 *
-	 * @param $title String: title to add
+	 * @param string $title title to add
 	 * @return Integer
 	 */
 	public function addLink( $title ) {
@@ -178,7 +181,8 @@ class LinkCache {
 	 * @return Integer
 	 */
 	public function addLinkObj( $nt ) {
-		global $wgAntiLockFlags;
+		global $wgAntiLockFlags, $wgContentHandlerUseDB;
+
 		wfProfileIn( __METHOD__ );
 
 		$key = $nt->getPrefixedDBkey();
@@ -210,8 +214,10 @@ class LinkCache {
 			$options = array();
 		}
 
-		$s = $db->selectRow( 'page',
-			array( 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
+		$f = array( 'page_id', 'page_len', 'page_is_redirect', 'page_latest' );
+		if ( $wgContentHandlerUseDB ) $f[] = 'page_content_model';
+
+		$s = $db->selectRow( 'page', $f,
 			array( 'page_namespace' => $nt->getNamespace(), 'page_title' => $nt->getDBkey() ),
 			__METHOD__, $options );
 		# Set fields...
diff --git a/includes/cache/LocalisationCache.php b/includes/cache/LocalisationCache.php
new file mode 100644
index 00000000..009b9507
--- /dev/null
+++ b/includes/cache/LocalisationCache.php
@@ -0,0 +1,1288 @@
+<?php
+/**
+ * Cache of the contents of localisation files.
+ *
+ * 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
+ */
+
+define( 'MW_LC_VERSION', 2 );
+
+/**
+ * Class for caching the contents of localisation files, Messages*.php
+ * and *.i18n.php.
+ *
+ * An instance of this class is available using Language::getLocalisationCache().
+ *
+ * The values retrieved from here are merged, containing items from extension
+ * files, core messages files and the language fallback sequence (e.g. zh-cn ->
+ * zh-hans -> en ). Some common errors are corrected, for example namespace
+ * names with spaces instead of underscores, but heavyweight processing, such
+ * as grammatical transformation, is done by the caller.
+ */
+class LocalisationCache {
+	/** Configuration associative array */
+	var $conf;
+
+	/**
+	 * True if recaching should only be done on an explicit call to recache().
+	 * Setting this reduces the overhead of cache freshness checking, which
+	 * requires doing a stat() for every extension i18n file.
+	 */
+	var $manualRecache = false;
+
+	/**
+	 * True to treat all files as expired until they are regenerated by this object.
+	 */
+	var $forceRecache = false;
+
+	/**
+	 * The cache data. 3-d array, where the first key is the language code,
+	 * the second key is the item key e.g. 'messages', and the third key is
+	 * an item specific subkey index. Some items are not arrays and so for those
+	 * items, there are no subkeys.
+	 */
+	var $data = array();
+
+	/**
+	 * The persistent store object. An instance of LCStore.
+	 *
+	 * @var LCStore
+	 */
+	var $store;
+
+	/**
+	 * A 2-d associative array, code/key, where presence indicates that the item
+	 * is loaded. Value arbitrary.
+	 *
+	 * For split items, if set, this indicates that all of the subitems have been
+	 * loaded.
+	 */
+	var $loadedItems = array();
+
+	/**
+	 * A 3-d associative array, code/key/subkey, where presence indicates that
+	 * the subitem is loaded. Only used for the split items, i.e. messages.
+	 */
+	var $loadedSubitems = array();
+
+	/**
+	 * An array where presence of a key indicates that that language has been
+	 * initialised. Initialisation includes checking for cache expiry and doing
+	 * any necessary updates.
+	 */
+	var $initialisedLangs = array();
+
+	/**
+	 * An array mapping non-existent pseudo-languages to fallback languages. This
+	 * is filled by initShallowFallback() when data is requested from a language
+	 * that lacks a Messages*.php file.
+	 */
+	var $shallowFallbacks = array();
+
+	/**
+	 * An array where the keys are codes that have been recached by this instance.
+	 */
+	var $recachedLangs = array();
+
+	/**
+	 * All item keys
+	 */
+	static public $allKeys = array(
+		'fallback', 'namespaceNames', 'bookstoreList',
+		'magicWords', 'messages', 'rtl', 'capitalizeAllNouns', 'digitTransformTable',
+		'separatorTransformTable', 'fallback8bitEncoding', 'linkPrefixExtension',
+		'linkTrail', 'namespaceAliases',
+		'dateFormats', 'datePreferences', 'datePreferenceMigrationMap',
+		'defaultDateFormat', 'extraUserToggles', 'specialPageAliases',
+		'imageFiles', 'preloadedMessages', 'namespaceGenderAliases',
+		'digitGroupingPattern', 'pluralRules', 'compiledPluralRules',
+	);
+
+	/**
+	 * Keys for items which consist of associative arrays, which may be merged
+	 * by a fallback sequence.
+	 */
+	static public $mergeableMapKeys = array( 'messages', 'namespaceNames',
+		'dateFormats', 'imageFiles', 'preloadedMessages'
+	);
+
+	/**
+	 * Keys for items which are a numbered array.
+	 */
+	static public $mergeableListKeys = array( 'extraUserToggles' );
+
+	/**
+	 * Keys for items which contain an array of arrays of equivalent aliases
+	 * for each subitem. The aliases may be merged by a fallback sequence.
+	 */
+	static public $mergeableAliasListKeys = array( 'specialPageAliases' );
+
+	/**
+	 * Keys for items which contain an associative array, and may be merged if
+	 * the primary value contains the special array key "inherit". That array
+	 * key is removed after the first merge.
+	 */
+	static public $optionalMergeKeys = array( 'bookstoreList' );
+
+	/**
+	 * Keys for items that are formatted like $magicWords
+	 */
+	static public $magicWordKeys = array( 'magicWords' );
+
+	/**
+	 * Keys for items where the subitems are stored in the backend separately.
+	 */
+	static public $splitKeys = array( 'messages' );
+
+	/**
+	 * Keys which are loaded automatically by initLanguage()
+	 */
+	static public $preloadedKeys = array( 'dateFormats', 'namespaceNames' );
+
+	/**
+	 * Associative array of cached plural rules. The key is the language code,
+	 * the value is an array of plural rules for that language.
+	 */
+	var $pluralRules = null;
+
+	var $mergeableKeys = null;
+
+	/**
+	 * Constructor.
+	 * For constructor parameters, see the documentation in DefaultSettings.php
+	 * for $wgLocalisationCacheConf.
+	 *
+	 * @param $conf Array
+	 * @throws MWException
+	 */
+	function __construct( $conf ) {
+		global $wgCacheDirectory;
+
+		$this->conf = $conf;
+		$storeConf = array();
+		if ( !empty( $conf['storeClass'] ) ) {
+			$storeClass = $conf['storeClass'];
+		} else {
+			switch ( $conf['store'] ) {
+				case 'files':
+				case 'file':
+					$storeClass = 'LCStore_CDB';
+					break;
+				case 'db':
+					$storeClass = 'LCStore_DB';
+					break;
+				case 'accel':
+					$storeClass = 'LCStore_Accel';
+					break;
+				case 'detect':
+					$storeClass = $wgCacheDirectory ? 'LCStore_CDB' : 'LCStore_DB';
+					break;
+				default:
+					throw new MWException(
+						'Please set $wgLocalisationCacheConf[\'store\'] to something sensible.' );
+			}
+		}
+
+		wfDebug( get_class( $this ) . ": using store $storeClass\n" );
+		if ( !empty( $conf['storeDirectory'] ) ) {
+			$storeConf['directory'] = $conf['storeDirectory'];
+		}
+
+		$this->store = new $storeClass( $storeConf );
+		foreach ( array( 'manualRecache', 'forceRecache' ) as $var ) {
+			if ( isset( $conf[$var] ) ) {
+				$this->$var = $conf[$var];
+			}
+		}
+	}
+
+	/**
+	 * Returns true if the given key is mergeable, that is, if it is an associative
+	 * array which can be merged through a fallback sequence.
+	 * @param $key
+	 * @return bool
+	 */
+	public function isMergeableKey( $key ) {
+		if ( $this->mergeableKeys === null ) {
+			$this->mergeableKeys = array_flip( array_merge(
+				self::$mergeableMapKeys,
+				self::$mergeableListKeys,
+				self::$mergeableAliasListKeys,
+				self::$optionalMergeKeys,
+				self::$magicWordKeys
+			) );
+		}
+		return isset( $this->mergeableKeys[$key] );
+	}
+
+	/**
+	 * Get a cache item.
+	 *
+	 * Warning: this may be slow for split items (messages), since it will
+	 * need to fetch all of the subitems from the cache individually.
+	 * @param $code
+	 * @param $key
+	 * @return mixed
+	 */
+	public function getItem( $code, $key ) {
+		if ( !isset( $this->loadedItems[$code][$key] ) ) {
+			wfProfileIn( __METHOD__ . '-load' );
+			$this->loadItem( $code, $key );
+			wfProfileOut( __METHOD__ . '-load' );
+		}
+
+		if ( $key === 'fallback' && isset( $this->shallowFallbacks[$code] ) ) {
+			return $this->shallowFallbacks[$code];
+		}
+
+		return $this->data[$code][$key];
+	}
+
+	/**
+	 * Get a subitem, for instance a single message for a given language.
+	 * @param $code
+	 * @param $key
+	 * @param $subkey
+	 * @return null
+	 */
+	public function getSubitem( $code, $key, $subkey ) {
+		if ( !isset( $this->loadedSubitems[$code][$key][$subkey] ) &&
+			 !isset( $this->loadedItems[$code][$key] ) ) {
+			wfProfileIn( __METHOD__ . '-load' );
+			$this->loadSubitem( $code, $key, $subkey );
+			wfProfileOut( __METHOD__ . '-load' );
+		}
+
+		if ( isset( $this->data[$code][$key][$subkey] ) ) {
+			return $this->data[$code][$key][$subkey];
+		} else {
+			return null;
+		}
+	}
+
+	/**
+	 * Get the list of subitem keys for a given item.
+	 *
+	 * This is faster than array_keys($lc->getItem(...)) for the items listed in
+	 * self::$splitKeys.
+	 *
+	 * Will return null if the item is not found, or false if the item is not an
+	 * array.
+	 * @param $code
+	 * @param $key
+	 * @return bool|null|string
+	 */
+	public function getSubitemList( $code, $key ) {
+		if ( in_array( $key, self::$splitKeys ) ) {
+			return $this->getSubitem( $code, 'list', $key );
+		} else {
+			$item = $this->getItem( $code, $key );
+			if ( is_array( $item ) ) {
+				return array_keys( $item );
+			} else {
+				return false;
+			}
+		}
+	}
+
+	/**
+	 * Load an item into the cache.
+	 * @param $code
+	 * @param $key
+	 */
+	protected function loadItem( $code, $key ) {
+		if ( !isset( $this->initialisedLangs[$code] ) ) {
+			$this->initLanguage( $code );
+		}
+
+		// Check to see if initLanguage() loaded it for us
+		if ( isset( $this->loadedItems[$code][$key] ) ) {
+			return;
+		}
+
+		if ( isset( $this->shallowFallbacks[$code] ) ) {
+			$this->loadItem( $this->shallowFallbacks[$code], $key );
+			return;
+		}
+
+		if ( in_array( $key, self::$splitKeys ) ) {
+			$subkeyList = $this->getSubitem( $code, 'list', $key );
+			foreach ( $subkeyList as $subkey ) {
+				if ( isset( $this->data[$code][$key][$subkey] ) ) {
+					continue;
+				}
+				$this->data[$code][$key][$subkey] = $this->getSubitem( $code, $key, $subkey );
+			}
+		} else {
+			$this->data[$code][$key] = $this->store->get( $code, $key );
+		}
+
+		$this->loadedItems[$code][$key] = true;
+	}
+
+	/**
+	 * Load a subitem into the cache
+	 * @param $code
+	 * @param $key
+	 * @param $subkey
+	 * @return
+	 */
+	protected function loadSubitem( $code, $key, $subkey ) {
+		if ( !in_array( $key, self::$splitKeys ) ) {
+			$this->loadItem( $code, $key );
+			return;
+		}
+
+		if ( !isset( $this->initialisedLangs[$code] ) ) {
+			$this->initLanguage( $code );
+		}
+
+		// Check to see if initLanguage() loaded it for us
+		if ( isset( $this->loadedItems[$code][$key] ) ||
+			 isset( $this->loadedSubitems[$code][$key][$subkey] ) ) {
+			return;
+		}
+
+		if ( isset( $this->shallowFallbacks[$code] ) ) {
+			$this->loadSubitem( $this->shallowFallbacks[$code], $key, $subkey );
+			return;
+		}
+
+		$value = $this->store->get( $code, "$key:$subkey" );
+		$this->data[$code][$key][$subkey] = $value;
+		$this->loadedSubitems[$code][$key][$subkey] = true;
+	}
+
+	/**
+	 * Returns true if the cache identified by $code is missing or expired.
+	 * @return bool
+	 */
+	public function isExpired( $code ) {
+		if ( $this->forceRecache && !isset( $this->recachedLangs[$code] ) ) {
+			wfDebug( __METHOD__ . "($code): forced reload\n" );
+			return true;
+		}
+
+		$deps = $this->store->get( $code, 'deps' );
+		$keys = $this->store->get( $code, 'list' );
+		$preload = $this->store->get( $code, 'preload' );
+		// Different keys may expire separately, at least in LCStore_Accel
+		if ( $deps === null || $keys === null || $preload === null ) {
+			wfDebug( __METHOD__ . "($code): cache missing, need to make one\n" );
+			return true;
+		}
+
+		foreach ( $deps as $dep ) {
+			// Because we're unserializing stuff from cache, we
+			// could receive objects of classes that don't exist
+			// anymore (e.g. uninstalled extensions)
+			// When this happens, always expire the cache
+			if ( !$dep instanceof CacheDependency || $dep->isExpired() ) {
+				wfDebug( __METHOD__ . "($code): cache for $code expired due to " .
+					get_class( $dep ) . "\n" );
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+	/**
+	 * Initialise a language in this object. Rebuild the cache if necessary.
+	 * @param $code
+	 * @throws MWException
+	 */
+	protected function initLanguage( $code ) {
+		if ( isset( $this->initialisedLangs[$code] ) ) {
+			return;
+		}
+
+		$this->initialisedLangs[$code] = true;
+
+		# If the code is of the wrong form for a Messages*.php file, do a shallow fallback
+		if ( !Language::isValidBuiltInCode( $code ) ) {
+			$this->initShallowFallback( $code, 'en' );
+			return;
+		}
+
+		# Recache the data if necessary
+		if ( !$this->manualRecache && $this->isExpired( $code ) ) {
+			if ( file_exists( Language::getMessagesFileName( $code ) ) ) {
+				$this->recache( $code );
+			} elseif ( $code === 'en' ) {
+				throw new MWException( 'MessagesEn.php is missing.' );
+			} else {
+				$this->initShallowFallback( $code, 'en' );
+			}
+			return;
+		}
+
+		# Preload some stuff
+		$preload = $this->getItem( $code, 'preload' );
+		if ( $preload === null ) {
+			if ( $this->manualRecache ) {
+				// No Messages*.php file. Do shallow fallback to en.
+				if ( $code === 'en' ) {
+					throw new MWException( 'No localisation cache found for English. ' .
+						'Please run maintenance/rebuildLocalisationCache.php.' );
+				}
+				$this->initShallowFallback( $code, 'en' );
+				return;
+			} else {
+				throw new MWException( 'Invalid or missing localisation cache.' );
+			}
+		}
+		$this->data[$code] = $preload;
+		foreach ( $preload as $key => $item ) {
+			if ( in_array( $key, self::$splitKeys ) ) {
+				foreach ( $item as $subkey => $subitem ) {
+					$this->loadedSubitems[$code][$key][$subkey] = true;
+				}
+			} else {
+				$this->loadedItems[$code][$key] = true;
+			}
+		}
+	}
+
+	/**
+	 * Create a fallback from one language to another, without creating a
+	 * complete persistent cache.
+	 * @param $primaryCode
+	 * @param $fallbackCode
+	 */
+	public function initShallowFallback( $primaryCode, $fallbackCode ) {
+		$this->data[$primaryCode] =& $this->data[$fallbackCode];
+		$this->loadedItems[$primaryCode] =& $this->loadedItems[$fallbackCode];
+		$this->loadedSubitems[$primaryCode] =& $this->loadedSubitems[$fallbackCode];
+		$this->shallowFallbacks[$primaryCode] = $fallbackCode;
+	}
+
+	/**
+	 * Read a PHP file containing localisation data.
+	 * @param $_fileName
+	 * @param $_fileType
+	 * @throws MWException
+	 * @return array
+	 */
+	protected function readPHPFile( $_fileName, $_fileType ) {
+		// Disable APC caching
+		$_apcEnabled = ini_set( 'apc.cache_by_default', '0' );
+		include( $_fileName );
+		ini_set( 'apc.cache_by_default', $_apcEnabled );
+
+		if ( $_fileType == 'core' || $_fileType == 'extension' ) {
+			$data = compact( self::$allKeys );
+		} elseif ( $_fileType == 'aliases' ) {
+			$data = compact( 'aliases' );
+		} else {
+			throw new MWException( __METHOD__ . ": Invalid file type: $_fileType" );
+		}
+		return $data;
+	}
+
+	/**
+	 * Get the compiled plural rules for a given language from the XML files.
+	 * @since 1.20
+	 */
+	public function getCompiledPluralRules( $code ) {
+		$rules = $this->getPluralRules( $code );
+		if ( $rules === null ) {
+			return null;
+		}
+		try {
+			$compiledRules = CLDRPluralRuleEvaluator::compile( $rules );
+		} catch( CLDRPluralRuleError $e ) {
+			wfDebugLog( 'l10n', $e->getMessage() . "\n" );
+			return array();
+		}
+		return $compiledRules;
+	}
+
+	/**
+	 * Get the plural rules for a given language from the XML files.
+	 * Cached.
+	 * @since 1.20
+	 */
+	public function getPluralRules( $code ) {
+		global $IP;
+
+		if ( $this->pluralRules === null ) {
+			$cldrPlural = "$IP/languages/data/plurals.xml";
+			$mwPlural = "$IP/languages/data/plurals-mediawiki.xml";
+			// Load CLDR plural rules
+			$this->loadPluralFile( $cldrPlural );
+			if ( file_exists( $mwPlural ) ) {
+				// Override or extend
+				$this->loadPluralFile( $mwPlural );
+			}
+		}
+		if ( !isset( $this->pluralRules[$code] ) ) {
+			return null;
+		} else {
+			return $this->pluralRules[$code];
+		}
+	}
+
+	/**
+	 * Load a plural XML file with the given filename, compile the relevant
+	 * rules, and save the compiled rules in a process-local cache.
+	 */
+	protected function loadPluralFile( $fileName ) {
+		$doc = new DOMDocument;
+		$doc->load( $fileName );
+		$rulesets = $doc->getElementsByTagName( "pluralRules" );
+		foreach ( $rulesets as $ruleset ) {
+			$codes = $ruleset->getAttribute( 'locales' );
+			$rules = array();
+			$ruleElements = $ruleset->getElementsByTagName( "pluralRule" );
+			foreach ( $ruleElements as $elt ) {
+				$rules[] = $elt->nodeValue;
+			}
+			foreach ( explode( ' ', $codes ) as $code ) {
+				$this->pluralRules[$code] = $rules;
+			}
+		}
+	}
+
+	/**
+	 * Read the data from the source files for a given language, and register
+	 * the relevant dependencies in the $deps array. If the localisation
+	 * exists, the data array is returned, otherwise false is returned.
+	 */
+	protected function readSourceFilesAndRegisterDeps( $code, &$deps ) {
+		global $IP;
+
+		$fileName = Language::getMessagesFileName( $code );
+		if ( !file_exists( $fileName ) ) {
+			return false;
+		}
+
+		$deps[] = new FileDependency( $fileName );
+		$data = $this->readPHPFile( $fileName, 'core' );
+
+		# Load CLDR plural rules for JavaScript
+		$data['pluralRules'] = $this->getPluralRules( $code );
+		# And for PHP
+		$data['compiledPluralRules'] = $this->getCompiledPluralRules( $code );
+
+		$deps['plurals'] = new FileDependency( "$IP/languages/data/plurals.xml" );
+		$deps['plurals-mw'] = new FileDependency( "$IP/languages/data/plurals-mediawiki.xml" );
+
+		return $data;
+	}
+
+	/**
+	 * Merge two localisation values, a primary and a fallback, overwriting the
+	 * primary value in place.
+	 * @param $key
+	 * @param $value
+	 * @param $fallbackValue
+	 */
+	protected function mergeItem( $key, &$value, $fallbackValue ) {
+		if ( !is_null( $value ) ) {
+			if ( !is_null( $fallbackValue ) ) {
+				if ( in_array( $key, self::$mergeableMapKeys ) ) {
+					$value = $value + $fallbackValue;
+				} elseif ( in_array( $key, self::$mergeableListKeys ) ) {
+					$value = array_unique( array_merge( $fallbackValue, $value ) );
+				} elseif ( in_array( $key, self::$mergeableAliasListKeys ) ) {
+					$value = array_merge_recursive( $value, $fallbackValue );
+				} elseif ( in_array( $key, self::$optionalMergeKeys ) ) {
+					if ( !empty( $value['inherit'] ) ) {
+						$value = array_merge( $fallbackValue, $value );
+					}
+
+					if ( isset( $value['inherit'] ) ) {
+						unset( $value['inherit'] );
+					}
+				} elseif ( in_array( $key, self::$magicWordKeys ) ) {
+					$this->mergeMagicWords( $value, $fallbackValue );
+				}
+			}
+		} else {
+			$value = $fallbackValue;
+		}
+	}
+
+	/**
+	 * @param $value
+	 * @param $fallbackValue
+	 */
+	protected function mergeMagicWords( &$value, $fallbackValue ) {
+		foreach ( $fallbackValue as $magicName => $fallbackInfo ) {
+			if ( !isset( $value[$magicName] ) ) {
+				$value[$magicName] = $fallbackInfo;
+			} else {
+				$oldSynonyms = array_slice( $fallbackInfo, 1 );
+				$newSynonyms = array_slice( $value[$magicName], 1 );
+				$synonyms = array_values( array_unique( array_merge(
+					$newSynonyms, $oldSynonyms ) ) );
+				$value[$magicName] = array_merge( array( $fallbackInfo[0] ), $synonyms );
+			}
+		}
+	}
+
+	/**
+	 * Given an array mapping language code to localisation value, such as is
+	 * found in extension *.i18n.php files, iterate through a fallback sequence
+	 * to merge the given data with an existing primary value.
+	 *
+	 * Returns true if any data from the extension array was used, false
+	 * otherwise.
+	 * @param $codeSequence
+	 * @param $key
+	 * @param $value
+	 * @param $fallbackValue
+	 * @return bool
+	 */
+	protected function mergeExtensionItem( $codeSequence, $key, &$value, $fallbackValue ) {
+		$used = false;
+		foreach ( $codeSequence as $code ) {
+			if ( isset( $fallbackValue[$code] ) ) {
+				$this->mergeItem( $key, $value, $fallbackValue[$code] );
+				$used = true;
+			}
+		}
+
+		return $used;
+	}
+
+	/**
+	 * Load localisation data for a given language for both core and extensions
+	 * and save it to the persistent cache store and the process cache
+	 * @param $code
+	 * @throws MWException
+	 */
+	public function recache( $code ) {
+		global $wgExtensionMessagesFiles;
+		wfProfileIn( __METHOD__ );
+
+		if ( !$code ) {
+			throw new MWException( "Invalid language code requested" );
+		}
+		$this->recachedLangs[$code] = true;
+
+		# Initial values
+		$initialData = array_combine(
+			self::$allKeys,
+			array_fill( 0, count( self::$allKeys ), null ) );
+		$coreData = $initialData;
+		$deps = array();
+
+		# Load the primary localisation from the source file
+		$data = $this->readSourceFilesAndRegisterDeps( $code, $deps );
+		if ( $data === false ) {
+			wfDebug( __METHOD__ . ": no localisation file for $code, using fallback to en\n" );
+			$coreData['fallback'] = 'en';
+		} else {
+			wfDebug( __METHOD__ . ": got localisation for $code from source\n" );
+
+			# Merge primary localisation
+			foreach ( $data as $key => $value ) {
+				$this->mergeItem( $key, $coreData[$key], $value );
+			}
+
+		}
+
+		# Fill in the fallback if it's not there already
+		if ( is_null( $coreData['fallback'] ) ) {
+			$coreData['fallback'] = $code === 'en' ? false : 'en';
+		}
+		if ( $coreData['fallback'] === false ) {
+			$coreData['fallbackSequence'] = array();
+		} else {
+			$coreData['fallbackSequence'] = array_map( 'trim', explode( ',', $coreData['fallback'] ) );
+			$len = count( $coreData['fallbackSequence'] );
+
+			# Ensure that the sequence ends at en
+			if ( $coreData['fallbackSequence'][$len - 1] !== 'en' ) {
+				$coreData['fallbackSequence'][] = 'en';
+			}
+
+			# Load the fallback localisation item by item and merge it
+			foreach ( $coreData['fallbackSequence'] as $fbCode ) {
+				# Load the secondary localisation from the source file to
+				# avoid infinite cycles on cyclic fallbacks
+				$fbData = $this->readSourceFilesAndRegisterDeps( $fbCode, $deps );
+				if ( $fbData === false ) {
+					continue;
+				}
+
+				foreach ( self::$allKeys as $key ) {
+					if ( !isset( $fbData[$key] ) ) {
+						continue;
+					}
+
+					if ( is_null( $coreData[$key] ) || $this->isMergeableKey( $key ) ) {
+						$this->mergeItem( $key, $coreData[$key], $fbData[$key] );
+					}
+				}
+			}
+		}
+
+		$codeSequence = array_merge( array( $code ), $coreData['fallbackSequence'] );
+
+		# Load the extension localisations
+		# This is done after the core because we know the fallback sequence now.
+		# But it has a higher precedence for merging so that we can support things
+		# like site-specific message overrides.
+		$allData = $initialData;
+		foreach ( $wgExtensionMessagesFiles as $fileName ) {
+			$data = $this->readPHPFile( $fileName, 'extension' );
+			$used = false;
+
+			foreach ( $data as $key => $item ) {
+				if ( $this->mergeExtensionItem( $codeSequence, $key, $allData[$key], $item ) ) {
+					$used = true;
+				}
+			}
+
+			if ( $used ) {
+				$deps[] = new FileDependency( $fileName );
+			}
+		}
+
+		# Merge core data into extension data
+		foreach ( $coreData as $key => $item ) {
+			$this->mergeItem( $key, $allData[$key], $item );
+		}
+
+		# Add cache dependencies for any referenced globals
+		$deps['wgExtensionMessagesFiles'] = new GlobalDependency( 'wgExtensionMessagesFiles' );
+		$deps['version'] = new ConstantDependency( 'MW_LC_VERSION' );
+
+		# Add dependencies to the cache entry
+		$allData['deps'] = $deps;
+
+		# Replace spaces with underscores in namespace names
+		$allData['namespaceNames'] = str_replace( ' ', '_', $allData['namespaceNames'] );
+
+		# And do the same for special page aliases. $page is an array.
+		foreach ( $allData['specialPageAliases'] as &$page ) {
+			$page = str_replace( ' ', '_', $page );
+		}
+		# Decouple the reference to prevent accidental damage
+		unset( $page );
+
+		# If there were no plural rules, return an empty array
+		if ( $allData['pluralRules'] === null ) {
+			$allData['pluralRules'] = array();
+		}
+		if ( $allData['compiledPluralRules'] === null ) {
+			$allData['compiledPluralRules'] = array();
+		}
+
+		# Set the list keys
+		$allData['list'] = array();
+		foreach ( self::$splitKeys as $key ) {
+			$allData['list'][$key] = array_keys( $allData[$key] );
+		}
+		# Run hooks
+		wfRunHooks( 'LocalisationCacheRecache', array( $this, $code, &$allData ) );
+
+		if ( is_null( $allData['namespaceNames'] ) ) {
+			throw new MWException( __METHOD__ . ': Localisation data failed sanity check! ' .
+				'Check that your languages/messages/MessagesEn.php file is intact.' );
+		}
+
+		# Set the preload key
+		$allData['preload'] = $this->buildPreload( $allData );
+
+		# Save to the process cache and register the items loaded
+		$this->data[$code] = $allData;
+		foreach ( $allData as $key => $item ) {
+			$this->loadedItems[$code][$key] = true;
+		}
+
+		# Save to the persistent cache
+		$this->store->startWrite( $code );
+		foreach ( $allData as $key => $value ) {
+			if ( in_array( $key, self::$splitKeys ) ) {
+				foreach ( $value as $subkey => $subvalue ) {
+					$this->store->set( "$key:$subkey", $subvalue );
+				}
+			} else {
+				$this->store->set( $key, $value );
+			}
+		}
+		$this->store->finishWrite();
+
+		# Clear out the MessageBlobStore
+		# HACK: If using a null (i.e. disabled) storage backend, we
+		# can't write to the MessageBlobStore either
+		if ( !$this->store instanceof LCStore_Null ) {
+			MessageBlobStore::clear();
+		}
+
+		wfProfileOut( __METHOD__ );
+	}
+
+	/**
+	 * Build the preload item from the given pre-cache data.
+	 *
+	 * The preload item will be loaded automatically, improving performance
+	 * for the commonly-requested items it contains.
+	 * @param $data
+	 * @return array
+	 */
+	protected function buildPreload( $data ) {
+		$preload = array( 'messages' => array() );
+		foreach ( self::$preloadedKeys as $key ) {
+			$preload[$key] = $data[$key];
+		}
+
+		foreach ( $data['preloadedMessages'] as $subkey ) {
+			if ( isset( $data['messages'][$subkey] ) ) {
+				$subitem = $data['messages'][$subkey];
+			} else {
+				$subitem = null;
+			}
+			$preload['messages'][$subkey] = $subitem;
+		}
+
+		return $preload;
+	}
+
+	/**
+	 * Unload the data for a given language from the object cache.
+	 * Reduces memory usage.
+	 * @param $code
+	 */
+	public function unload( $code ) {
+		unset( $this->data[$code] );
+		unset( $this->loadedItems[$code] );
+		unset( $this->loadedSubitems[$code] );
+		unset( $this->initialisedLangs[$code] );
+
+		foreach ( $this->shallowFallbacks as $shallowCode => $fbCode ) {
+			if ( $fbCode === $code ) {
+				$this->unload( $shallowCode );
+			}
+		}
+	}
+
+	/**
+	 * Unload all data
+	 */
+	public function unloadAll() {
+		foreach ( $this->initialisedLangs as $lang => $unused ) {
+			$this->unload( $lang );
+		}
+	}
+
+	/**
+	 * Disable the storage backend
+	 */
+	public function disableBackend() {
+		$this->store = new LCStore_Null;
+		$this->manualRecache = false;
+	}
+}
+
+/**
+ * Interface for the persistence layer of LocalisationCache.
+ *
+ * The persistence layer is two-level hierarchical cache. The first level
+ * is the language, the second level is the item or subitem.
+ *
+ * Since the data for a whole language is rebuilt in one operation, it needs
+ * to have a fast and atomic method for deleting or replacing all of the
+ * current data for a given language. The interface reflects this bulk update
+ * operation. Callers writing to the cache must first call startWrite(), then
+ * will call set() a couple of thousand times, then will call finishWrite()
+ * to commit the operation. When finishWrite() is called, the cache is
+ * expected to delete all data previously stored for that language.
+ *
+ * The values stored are PHP variables suitable for serialize(). Implementations
+ * of LCStore are responsible for serializing and unserializing.
+ */
+interface LCStore {
+	/**
+	 * Get a value.
+	 * @param string $code Language code
+	 * @param string $key Cache key
+	 */
+	function get( $code, $key );
+
+	/**
+	 * Start a write transaction.
+	 * @param $code Language code
+	 */
+	function startWrite( $code );
+
+	/**
+	 * Finish a write transaction.
+	 */
+	function finishWrite();
+
+	/**
+	 * Set a key to a given value. startWrite() must be called before this
+	 * is called, and finishWrite() must be called afterwards.
+	 * @param $key
+	 * @param $value
+	 */
+	function set( $key, $value );
+}
+
+/**
+ * LCStore implementation which uses PHP accelerator to store data.
+ * This will work if one of XCache, WinCache or APC cacher is configured.
+ * (See ObjectCache.php)
+ */
+class LCStore_Accel implements LCStore {
+	var $currentLang;
+	var $keys;
+
+	public function __construct() {
+		$this->cache = wfGetCache( CACHE_ACCEL );
+	}
+
+	public function get( $code, $key ) {
+		$k = wfMemcKey( 'l10n', $code, 'k', $key );
+		$r = $this->cache->get( $k );
+		return $r === false ? null : $r;
+	}
+
+	public function startWrite( $code ) {
+		$k = wfMemcKey( 'l10n', $code, 'l' );
+		$keys = $this->cache->get( $k );
+		if ( $keys ) {
+			foreach ( $keys as $k ) {
+				$this->cache->delete( $k );
+			}
+		}
+		$this->currentLang = $code;
+		$this->keys = array();
+	}
+
+	public function finishWrite() {
+		if ( $this->currentLang ) {
+			$k = wfMemcKey( 'l10n', $this->currentLang, 'l' );
+			$this->cache->set( $k, array_keys( $this->keys ) );
+		}
+		$this->currentLang = null;
+		$this->keys = array();
+	}
+
+	public function set( $key, $value ) {
+		if ( $this->currentLang ) {
+			$k = wfMemcKey( 'l10n', $this->currentLang, 'k', $key );
+			$this->keys[$k] = true;
+			$this->cache->set( $k, $value );
+		}
+	}
+}
+
+/**
+ * LCStore implementation which uses the standard DB functions to store data.
+ * This will work on any MediaWiki installation.
+ */
+class LCStore_DB implements LCStore {
+	var $currentLang;
+	var $writesDone = false;
+
+	/**
+	 * @var DatabaseBase
+	 */
+	var $dbw;
+	var $batch;
+	var $readOnly = false;
+
+	public function get( $code, $key ) {
+		if ( $this->writesDone ) {
+			$db = wfGetDB( DB_MASTER );
+		} else {
+			$db = wfGetDB( DB_SLAVE );
+		}
+		$row = $db->selectRow( 'l10n_cache', array( 'lc_value' ),
+			array( 'lc_lang' => $code, 'lc_key' => $key ), __METHOD__ );
+		if ( $row ) {
+			return unserialize( $row->lc_value );
+		} else {
+			return null;
+		}
+	}
+
+	public function startWrite( $code ) {
+		if ( $this->readOnly ) {
+			return;
+		}
+
+		if ( !$code ) {
+			throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
+		}
+
+		$this->dbw = wfGetDB( DB_MASTER );
+		try {
+			$this->dbw->begin( __METHOD__ );
+			$this->dbw->delete( 'l10n_cache', array( 'lc_lang' => $code ), __METHOD__ );
+		} catch ( DBQueryError $e ) {
+			if ( $this->dbw->wasReadOnlyError() ) {
+				$this->readOnly = true;
+				$this->dbw->rollback( __METHOD__ );
+				return;
+			} else {
+				throw $e;
+			}
+		}
+
+		$this->currentLang = $code;
+		$this->batch = array();
+	}
+
+	public function finishWrite() {
+		if ( $this->readOnly ) {
+			return;
+		}
+
+		if ( $this->batch ) {
+			$this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
+		}
+
+		$this->dbw->commit( __METHOD__ );
+		$this->currentLang = null;
+		$this->dbw = null;
+		$this->batch = array();
+		$this->writesDone = true;
+	}
+
+	public function set( $key, $value ) {
+		if ( $this->readOnly ) {
+			return;
+		}
+
+		if ( is_null( $this->currentLang ) ) {
+			throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
+		}
+
+		$this->batch[] = array(
+			'lc_lang' => $this->currentLang,
+			'lc_key' => $key,
+			'lc_value' => serialize( $value ) );
+
+		if ( count( $this->batch ) >= 100 ) {
+			$this->dbw->insert( 'l10n_cache', $this->batch, __METHOD__ );
+			$this->batch = array();
+		}
+	}
+}
+
+/**
+ * LCStore implementation which stores data as a collection of CDB files in the
+ * directory given by $wgCacheDirectory. If $wgCacheDirectory is not set, this
+ * will throw an exception.
+ *
+ * Profiling indicates that on Linux, this implementation outperforms MySQL if
+ * the directory is on a local filesystem and there is ample kernel cache
+ * space. The performance advantage is greater when the DBA extension is
+ * available than it is with the PHP port.
+ *
+ * See Cdb.php and http://cr.yp.to/cdb.html
+ */
+class LCStore_CDB implements LCStore {
+	var $readers, $writer, $currentLang, $directory;
+
+	function __construct( $conf = array() ) {
+		global $wgCacheDirectory;
+
+		if ( isset( $conf['directory'] ) ) {
+			$this->directory = $conf['directory'];
+		} else {
+			$this->directory = $wgCacheDirectory;
+		}
+	}
+
+	public function get( $code, $key ) {
+		if ( !isset( $this->readers[$code] ) ) {
+			$fileName = $this->getFileName( $code );
+
+			if ( !file_exists( $fileName ) ) {
+				$this->readers[$code] = false;
+			} else {
+				$this->readers[$code] = CdbReader::open( $fileName );
+			}
+		}
+
+		if ( !$this->readers[$code] ) {
+			return null;
+		} else {
+			$value = $this->readers[$code]->get( $key );
+
+			if ( $value === false ) {
+				return null;
+			}
+			return unserialize( $value );
+		}
+	}
+
+	public function startWrite( $code ) {
+		if ( !file_exists( $this->directory ) ) {
+			if ( !wfMkdirParents( $this->directory, null, __METHOD__ ) ) {
+				throw new MWException( "Unable to create the localisation store " .
+					"directory \"{$this->directory}\"" );
+			}
+		}
+
+		// Close reader to stop permission errors on write
+		if ( !empty( $this->readers[$code] ) ) {
+			$this->readers[$code]->close();
+		}
+
+		$this->writer = CdbWriter::open( $this->getFileName( $code ) );
+		$this->currentLang = $code;
+	}
+
+	public function finishWrite() {
+		// Close the writer
+		$this->writer->close();
+		$this->writer = null;
+		unset( $this->readers[$this->currentLang] );
+		$this->currentLang = null;
+	}
+
+	public function set( $key, $value ) {
+		if ( is_null( $this->writer ) ) {
+			throw new MWException( __CLASS__ . ': must call startWrite() before calling set()' );
+		}
+		$this->writer->set( $key, serialize( $value ) );
+	}
+
+	protected function getFileName( $code ) {
+		if ( strval( $code ) === '' || strpos( $code, '/' ) !== false ) {
+			throw new MWException( __METHOD__ . ": Invalid language \"$code\"" );
+		}
+		return "{$this->directory}/l10n_cache-$code.cdb";
+	}
+}
+
+/**
+ * Null store backend, used to avoid DB errors during install
+ */
+class LCStore_Null implements LCStore {
+	public function get( $code, $key ) {
+		return null;
+	}
+
+	public function startWrite( $code ) {}
+	public function finishWrite() {}
+	public function set( $key, $value ) {}
+}
+
+/**
+ * A localisation cache optimised for loading large amounts of data for many
+ * languages. Used by rebuildLocalisationCache.php.
+ */
+class LocalisationCache_BulkLoad extends LocalisationCache {
+	/**
+	 * A cache of the contents of data files.
+	 * Core files are serialized to avoid using ~1GB of RAM during a recache.
+	 */
+	var $fileCache = array();
+
+	/**
+	 * Most recently used languages. Uses the linked-list aspect of PHP hashtables
+	 * to keep the most recently used language codes at the end of the array, and
+	 * the language codes that are ready to be deleted at the beginning.
+	 */
+	var $mruLangs = array();
+
+	/**
+	 * Maximum number of languages that may be loaded into $this->data
+	 */
+	var $maxLoadedLangs = 10;
+
+	/**
+	 * @param $fileName
+	 * @param $fileType
+	 * @return array|mixed
+	 */
+	protected function readPHPFile( $fileName, $fileType ) {
+		$serialize = $fileType === 'core';
+		if ( !isset( $this->fileCache[$fileName][$fileType] ) ) {
+			$data = parent::readPHPFile( $fileName, $fileType );
+
+			if ( $serialize ) {
+				$encData = serialize( $data );
+			} else {
+				$encData = $data;
+			}
+
+			$this->fileCache[$fileName][$fileType] = $encData;
+
+			return $data;
+		} elseif ( $serialize ) {
+			return unserialize( $this->fileCache[$fileName][$fileType] );
+		} else {
+			return $this->fileCache[$fileName][$fileType];
+		}
+	}
+
+	/**
+	 * @param $code
+	 * @param $key
+	 * @return mixed
+	 */
+	public function getItem( $code, $key ) {
+		unset( $this->mruLangs[$code] );
+		$this->mruLangs[$code] = true;
+		return parent::getItem( $code, $key );
+	}
+
+	/**
+	 * @param $code
+	 * @param $key
+	 * @param $subkey
+	 * @return
+	 */
+	public function getSubitem( $code, $key, $subkey ) {
+		unset( $this->mruLangs[$code] );
+		$this->mruLangs[$code] = true;
+		return parent::getSubitem( $code, $key, $subkey );
+	}
+
+	/**
+	 * @param $code
+	 */
+	public function recache( $code ) {
+		parent::recache( $code );
+		unset( $this->mruLangs[$code] );
+		$this->mruLangs[$code] = true;
+		$this->trimCache();
+	}
+
+	/**
+	 * @param $code
+	 */
+	public function unload( $code ) {
+		unset( $this->mruLangs[$code] );
+		parent::unload( $code );
+	}
+
+	/**
+	 * Unload cached languages until there are less than $this->maxLoadedLangs
+	 */
+	protected function trimCache() {
+		while ( count( $this->data ) > $this->maxLoadedLangs && count( $this->mruLangs ) ) {
+			reset( $this->mruLangs );
+			$code = key( $this->mruLangs );
+			wfDebug( __METHOD__ . ": unloading $code\n" );
+			$this->unload( $code );
+		}
+	}
+
+}
diff --git a/includes/cache/MessageCache.php b/includes/cache/MessageCache.php
index b854a2ec..c406b5c3 100644
--- a/includes/cache/MessageCache.php
+++ b/includes/cache/MessageCache.php
@@ -60,26 +60,6 @@ class MessageCache {
 	protected $mLoadedLanguages = array();
 
 	/**
-	 * Used for automatic detection of most used messages.
-	 */
-	protected $mRequestedMessages = array();
-
-	/**
-	 * How long the message request counts are stored. Longer period gives
-	 * better sample, but also takes longer to adapt changes. The counts
-	 * are aggregrated per day, regardless of the value of this variable.
-	 */
-	protected static $mAdaptiveDataAge = 604800; // Is 7*24*3600
-
-	/**
-	 * Filter the tail of less used messages that are requested more seldom
-	 * than this factor times the number of request of most requested message.
-	 * These messages are not loaded in the default set, but are still cached
-	 * individually on demand with the normal cache expiry time.
-	 */
-	protected static $mAdaptiveInclusionThreshold = 0.05;
-
-	/**
 	 * Singleton instance
 	 *
 	 * @var MessageCache
@@ -142,7 +122,7 @@ class MessageCache {
 	 * Actual format of the file depends on the $wgLocalMessageCacheSerialized
 	 * setting.
 	 *
-	 * @param $hash String: the hash of contents, to check validity.
+	 * @param string $hash the hash of contents, to check validity.
 	 * @param $code Mixed: Optional language code, see documenation of load().
 	 * @return bool on failure.
 	 */
@@ -277,12 +257,15 @@ class MessageCache {
 	 * or false if populating empty cache fails. Also returns true if MessageCache
 	 * is disabled.
 	 *
-	 * @param $code String: language to which load messages
+	 * @param bool|String $code String: language to which load messages
+	 * @throws MWException
 	 * @return bool
 	 */
 	function load( $code = false ) {
 		global $wgUseLocalMessageCache;
 
+		$exception = null; // deferred error
+
 		if( !is_string( $code ) ) {
 			# This isn't really nice, so at least make a note about it and try to
 			# fall back
@@ -344,35 +327,52 @@ class MessageCache {
 			$where[] = 'cache is empty';
 			$where[] = 'loading from database';
 
-			$this->lock( $cacheKey );
-
+			if ( $this->lock( $cacheKey ) ) {
+				$that = $this;
+				$osc = new ScopedCallback( function() use ( $that, $cacheKey ) {
+					$that->unlock( $cacheKey );
+				} );
+			}
 			# Limit the concurrency of loadFromDB to a single process
 			# This prevents the site from going down when the cache expires
 			$statusKey = wfMemcKey( 'messages', $code, 'status' );
 			$success = $this->mMemc->add( $statusKey, 'loading', MSG_LOAD_TIMEOUT );
-			if ( $success ) {
+			if ( $success ) { // acquired lock
+				$cache = $this->mMemc;
+				$isc = new ScopedCallback( function() use ( $cache, $statusKey ) {
+					$cache->delete( $statusKey );
+				} );
 				$cache = $this->loadFromDB( $code );
 				$success = $this->setCache( $cache, $code );
-			}
-			if ( $success ) {
-				$success = $this->saveToCaches( $cache, true, $code );
-				if ( $success ) {
-					$this->mMemc->delete( $statusKey );
+				if ( $success ) { // messages loaded
+					$success = $this->saveToCaches( $cache, true, $code );
+					$isc = null; // unlock
+					if ( !$success ) {
+						$this->mMemc->set( $statusKey, 'error', 60 * 5 );
+						wfDebug( __METHOD__ . ": set() error: restart memcached server!\n" );
+						$exception = new MWException( "Could not save cache for '$code'." );
+					}
 				} else {
-					$this->mMemc->set( $statusKey, 'error', 60 * 5 );
-					wfDebug( "MemCached set error in MessageCache: restart memcached server!\n" );
+					$isc = null; // unlock
+					$exception = new MWException( "Could not load cache from DB for '$code'." );
 				}
+			} else {
+				$exception = new MWException( "Could not acquire '$statusKey' lock." );
 			}
-			$this->unlock($cacheKey);
+			$osc = null; // unlock
 		}
 
 		if ( !$success ) {
-			# Bad luck... this should not happen
-			$where[] = 'loading FAILED - cache is disabled';
-			$info = implode( ', ', $where );
-			wfDebug( __METHOD__ . ": Loading $code... $info\n" );
 			$this->mDisable = true;
 			$this->mCache = false;
+			// This used to go on, but that led to lots of nasty side
+			// effects like gadgets and sidebar getting cached with their
+			// default content
+			if ( $exception instanceof Exception ) {
+				throw $exception;
+			} else {
+				throw new MWException( "MessageCache failed to load messages" );
+			}
 		} else {
 			# All good, just record the success
 			$info = implode( ', ', $where );
@@ -388,7 +388,7 @@ class MessageCache {
 	 * $wgMaxMsgCacheEntrySize are assigned a special value, and are loaded
 	 * on-demand from the database later.
 	 *
-	 * @param $code String: language code.
+	 * @param string $code language code.
 	 * @return Array: loaded messages for storing in caches.
 	 */
 	function loadFromDB( $code ) {
@@ -404,19 +404,20 @@ class MessageCache {
 		);
 
 		$mostused = array();
-		if ( $wgAdaptiveMessageCache ) {
-			$mostused = $this->getMostUsedMessages();
-			if ( $code !== $wgLanguageCode ) {
-				foreach ( $mostused as $key => $value ) {
-					$mostused[$key] = "$value/$code";
-				}
+		if ( $wgAdaptiveMessageCache && $code !== $wgLanguageCode ) {
+			if ( !isset( $this->mCache[$wgLanguageCode] ) ) {
+				$this->load( $wgLanguageCode );
+			}
+			$mostused = array_keys( $this->mCache[$wgLanguageCode] );
+			foreach ( $mostused as $key => $value ) {
+				$mostused[$key] = "$value/$code";
 			}
 		}
 
 		if ( count( $mostused ) ) {
 			$conds['page_title'] = $mostused;
 		} elseif ( $code !== $wgLanguageCode ) {
-			$conds[] = 'page_title' . $dbr->buildLike( $dbr->anyString(), "/$code" );
+			$conds[] = 'page_title' . $dbr->buildLike( $dbr->anyString(), '/', $code );
 		} else {
 			# Effectively disallows use of '/' character in NS_MEDIAWIKI for uses
 			# other than language code.
@@ -459,12 +460,6 @@ class MessageCache {
 			$cache[$row->page_title] = $entry;
 		}
 
-		foreach ( $mostused as $key ) {
-			if ( !isset( $cache[$key] ) ) {
-				$cache[$key] = '!NONEXISTENT';
-			}
-		}
-
 		$cache['VERSION'] = MSG_CACHE_VERSION;
 		wfProfileOut( __METHOD__ );
 		return $cache;
@@ -473,7 +468,7 @@ class MessageCache {
 	/**
 	 * Updates cache as necessary when message page is changed
 	 *
-	 * @param $title String: name of the page changed.
+	 * @param string $title name of the page changed.
 	 * @param $text Mixed: new contents of the page.
 	 */
 	public function replace( $title, $text ) {
@@ -512,7 +507,7 @@ class MessageCache {
 
 		// Also delete cached sidebar... just in case it is affected
 		$codes = array( $code );
-		if ( $code === 'en'  ) {
+		if ( $code === 'en' ) {
 			// Delete all sidebars, like for example on action=purge on the
 			// sidebar messages
 			$codes = array_keys( Language::fetchLanguageNames() );
@@ -536,9 +531,9 @@ class MessageCache {
 	/**
 	 * Shortcut to update caches.
 	 *
-	 * @param $cache Array: cached messages with a version.
-	 * @param $memc Bool: Wether to update or not memcache.
-	 * @param $code String: Language code.
+	 * @param array $cache cached messages with a version.
+	 * @param bool $memc Wether to update or not memcache.
+	 * @param string $code Language code.
 	 * @return bool on somekind of error.
 	 */
 	protected function saveToCaches( $cache, $memc = true, $code = false ) {
@@ -558,7 +553,7 @@ class MessageCache {
 			$serialized = serialize( $cache );
 			$hash = md5( $serialized );
 			$this->mMemc->set( wfMemcKey( 'messages', $code, 'hash' ), $hash, $this->mExpiry );
-			if ($wgLocalMessageCacheSerialized) {
+			if ( $wgLocalMessageCacheSerialized ) {
 				$this->saveToLocal( $serialized, $hash, $code );
 			} else {
 				$this->saveToScript( $cache, $hash, $code );
@@ -593,10 +588,10 @@ class MessageCache {
 	/**
 	 * Get a message from either the content language or the user language.
 	 *
-	 * @param $key String: the message cache key
+	 * @param string $key the message cache key
 	 * @param $useDB Boolean: get the message from the DB, false to use only
 	 *               the localisation
-	 * @param $langcode String: code of the language to get the message for, if
+	 * @param bool|string $langcode Code of the language to get the message for, if
 	 *                  it is a valid code create a language for that language,
 	 *                  if it is a string but not a valid code then make a basic
 	 *                  language object, if it is a false boolean then use the
@@ -607,6 +602,7 @@ class MessageCache {
 	 * @param $isFullKey Boolean: specifies whether $key is a two part key
 	 *                   "msg/lang".
 	 *
+	 * @throws MWException
 	 * @return string|bool
 	 */
 	function get( $key, $useDB = true, $langcode = true, $isFullKey = false ) {
@@ -645,13 +641,6 @@ class MessageCache {
 			$uckey = $wgContLang->ucfirst( $lckey );
 		}
 
-		/**
-		 * Record each message request, but only once per request.
-		 * This information is not used unless $wgAdaptiveMessageCache
-		 * is enabled.
-		 */
-		$this->mRequestedMessages[$uckey] = true;
-
 		# Try the MediaWiki namespace
 		if( !$this->mDisable && $useDB ) {
 			$title = $uckey;
@@ -712,14 +701,12 @@ class MessageCache {
 	 * Get a message from the MediaWiki namespace, with caching. The key must
 	 * first be converted to two-part lang/msg form if necessary.
 	 *
-	 * @param $title String: Message cache key with initial uppercase letter.
-	 * @param $code String: code denoting the language to try.
+	 * @param string $title Message cache key with initial uppercase letter.
+	 * @param string $code code denoting the language to try.
 	 *
 	 * @return string|bool False on failure
 	 */
 	function getMsgFromNamespace( $title, $code ) {
-		global $wgAdaptiveMessageCache;
-
 		$this->load( $code );
 		if ( isset( $this->mCache[$code][$title] ) ) {
 			$entry = $this->mCache[$code][$title];
@@ -738,15 +725,7 @@ class MessageCache {
 				return $message;
 			}
 
-			/**
-			 * If message cache is in normal mode, it is guaranteed
-			 * (except bugs) that there is always entry (or placeholder)
-			 * in the cache if message exists. Thus we can do minor
-			 * performance improvement and return false early.
-			 */
-			if ( !$wgAdaptiveMessageCache ) {
-				return false;
-			}
+			return false;
 		}
 
 		# Try the individual message cache
@@ -770,16 +749,32 @@ class MessageCache {
 			Title::makeTitle( NS_MEDIAWIKI, $title ), false, Revision::READ_LATEST
 		);
 		if ( $revision ) {
-			$message = $revision->getText();
-			if ($message === false) {
+			$content = $revision->getContent();
+			if ( !$content ) {
 				// A possibly temporary loading failure.
 				wfDebugLog( 'MessageCache', __METHOD__ . ": failed to load message page text for {$title} ($code)" );
+				$message = null; // no negative caching
 			} else {
-				$this->mCache[$code][$title] = ' ' . $message;
-				$this->mMemc->set( $titleKey, ' ' . $message, $this->mExpiry );
+				// XXX: Is this the right way to turn a Content object into a message?
+				// NOTE: $content is typically either WikitextContent, JavaScriptContent or CssContent.
+				//       MessageContent is *not* used for storing messages, it's only used for wrapping them when needed.
+				$message = $content->getWikitextForTransclusion();
+
+				if ( $message === false || $message === null ) {
+					wfDebugLog( 'MessageCache', __METHOD__ . ": message content doesn't provide wikitext "
+								. "(content model: " . $content->getContentHandler() . ")" );
+
+					$message = false; // negative caching
+				} else {
+					$this->mCache[$code][$title] = ' ' . $message;
+					$this->mMemc->set( $titleKey, ' ' . $message, $this->mExpiry );
+				}
 			}
 		} else {
-			$message = false;
+			$message = false; // negative caching
+		}
+
+		if ( $message === false ) { // negative caching
 			$this->mCache[$code][$title] = '!NONEXISTENT';
 			$this->mMemc->set( $titleKey, '!NONEXISTENT', $this->mExpiry );
 		}
@@ -845,7 +840,7 @@ class MessageCache {
 	 * @param $linestart bool
 	 * @param $interface bool
 	 * @param $language
-	 * @return ParserOutput
+	 * @return ParserOutput|string
 	 */
 	public function parse( $text, $title = null, $linestart = true, $interface = false, $language = null  ) {
 		if ( $this->mInParser ) {
@@ -890,7 +885,7 @@ class MessageCache {
 	 */
 	function clear() {
 		$langs = Language::fetchLanguageNames( null, 'mw' );
-		foreach ( array_keys($langs) as $code ) {
+		foreach ( array_keys( $langs ) as $code ) {
 			# Global cache
 			$this->mMemc->delete( wfMemcKey( 'messages', $code ) );
 			# Invalidate all local caches
@@ -919,82 +914,6 @@ class MessageCache {
 		return array( $message, $lang );
 	}
 
-	public static function logMessages() {
-		wfProfileIn( __METHOD__ );
-		global $wgAdaptiveMessageCache;
-		if ( !$wgAdaptiveMessageCache || !self::$instance instanceof MessageCache ) {
-			wfProfileOut( __METHOD__ );
-			return;
-		}
-
-		$cachekey = wfMemckey( 'message-profiling' );
-		$cache = wfGetCache( CACHE_DB );
-		$data = $cache->get( $cachekey );
-
-		if ( !$data ) {
-			$data = array();
-		}
-
-		$age = self::$mAdaptiveDataAge;
-		$filterDate = substr( wfTimestamp( TS_MW, time() - $age ), 0, 8 );
-		foreach ( array_keys( $data ) as $key ) {
-			if ( $key < $filterDate ) {
-				unset( $data[$key] );
-			}
-		}
-
-		$index = substr( wfTimestampNow(), 0, 8 );
-		if ( !isset( $data[$index] ) ) {
-			$data[$index] = array();
-		}
-
-		foreach ( self::$instance->mRequestedMessages as $message => $_ ) {
-			if ( !isset( $data[$index][$message] ) ) {
-				$data[$index][$message] = 0;
-			}
-			$data[$index][$message]++;
-		}
-
-		$cache->set( $cachekey, $data );
-		wfProfileOut( __METHOD__ );
-	}
-
-	/**
-	 * @return array
-	 */
-	public function getMostUsedMessages() {
-		wfProfileIn( __METHOD__ );
-		$cachekey = wfMemcKey( 'message-profiling' );
-		$cache = wfGetCache( CACHE_DB );
-		$data = $cache->get( $cachekey );
-		if ( !$data ) {
-			wfProfileOut( __METHOD__ );
-			return array();
-		}
-
-		$list = array();
-
-		foreach( $data as $messages ) {
-			foreach( $messages as $message => $count ) {
-				$key = $message;
-				if ( !isset( $list[$key] ) ) {
-					$list[$key] = 0;
-				}
-				$list[$key] += $count;
-			}
-		}
-
-		$max = max( $list );
-		foreach ( $list as $message => $count ) {
-			if ( $count < intval( $max * self::$mAdaptiveInclusionThreshold ) ) {
-				unset( $list[$message] );
-			}
-		}
-
-		wfProfileOut( __METHOD__ );
-		return array_keys( $list );
-	}
-
 	/**
 	 * Get all message keys stored in the message cache for a given language.
 	 * If $code is the content language code, this will return all message keys
diff --git a/includes/cache/ProcessCacheLRU.php b/includes/cache/ProcessCacheLRU.php
index f215ebd8..76c76f37 100644
--- a/includes/cache/ProcessCacheLRU.php
+++ b/includes/cache/ProcessCacheLRU.php
@@ -28,6 +28,8 @@
 class ProcessCacheLRU {
 	/** @var Array */
 	protected $cache = array(); // (key => prop => value)
+	/** @var Array */
+	protected $cacheTimes = array(); // (key => prop => UNIX timestamp)
 
 	protected $maxCacheKeys; // integer; max entries
 
@@ -44,7 +46,7 @@ class ProcessCacheLRU {
 
 	/**
 	 * Set a property field for a cache entry.
-	 * This will prune the cache if it gets too large.
+	 * This will prune the cache if it gets too large based on LRU.
 	 * If the item is already set, it will be pushed to the top of the cache.
 	 *
 	 * @param $key string
@@ -57,9 +59,12 @@ class ProcessCacheLRU {
 			$this->ping( $key ); // push to top
 		} elseif ( count( $this->cache ) >= $this->maxCacheKeys ) {
 			reset( $this->cache );
-			unset( $this->cache[key( $this->cache )] );
+			$evictKey = key( $this->cache );
+			unset( $this->cache[$evictKey] );
+			unset( $this->cacheTimes[$evictKey] );
 		}
 		$this->cache[$key][$prop] = $value;
+		$this->cacheTimes[$key][$prop] = time();
 	}
 
 	/**
@@ -67,10 +72,14 @@ class ProcessCacheLRU {
 	 *
 	 * @param $key string
 	 * @param $prop string
+	 * @param $maxAge integer Ignore items older than this many seconds (since 1.21)
 	 * @return bool
 	 */
-	public function has( $key, $prop ) {
-		return isset( $this->cache[$key][$prop] );
+	public function has( $key, $prop, $maxAge = 0 ) {
+		if ( isset( $this->cache[$key][$prop] ) ) {
+			return ( $maxAge <= 0 || ( time() - $this->cacheTimes[$key][$prop] ) <= $maxAge );
+		}
+		return false;
 	}
 
 	/**
@@ -100,9 +109,11 @@ class ProcessCacheLRU {
 	public function clear( $keys = null ) {
 		if ( $keys === null ) {
 			$this->cache = array();
+			$this->cacheTimes = array();
 		} else {
 			foreach ( (array)$keys as $key ) {
 				unset( $this->cache[$key] );
+				unset( $this->cacheTimes[$key] );
 			}
 		}
 	}
diff --git a/includes/cache/SquidUpdate.php b/includes/cache/SquidUpdate.php
index 423e3884..39bf4c9f 100644
--- a/includes/cache/SquidUpdate.php
+++ b/includes/cache/SquidUpdate.php
@@ -61,13 +61,13 @@ class SquidUpdate {
 			array( 'page_namespace', 'page_title' ),
 			array(
 				'pl_namespace' => $title->getNamespace(),
-				'pl_title'     => $title->getDBkey(),
+				'pl_title' => $title->getDBkey(),
 				'pl_from=page_id' ),
 			__METHOD__ );
 		$blurlArr = $title->getSquidURLs();
-		if ( $dbr->numRows( $res ) <= $wgMaxSquidPurgeTitles ) {
+		if ( $res->numRows() <= $wgMaxSquidPurgeTitles ) {
 			foreach ( $res as $BL ) {
-				$tobj = Title::makeTitle( $BL->page_namespace, $BL->page_title ) ;
+				$tobj = Title::makeTitle( $BL->page_namespace, $BL->page_title );
 				$blurlArr[] = $tobj->getInternalURL();
 			}
 		}
@@ -129,6 +129,8 @@ class SquidUpdate {
 			return;
 		}
 
+		wfDebug( "Squid purge: " . implode( ' ', $urlArr ) . "\n" );
+
 		if ( $wgHTCPMulticastRouting ) {
 			SquidUpdate::HTCPPurge( $urlArr );
 		}
@@ -249,11 +251,11 @@ class SquidUpdate {
 	static function expand( $url ) {
 		return wfExpandUrl( $url, PROTO_INTERNAL );
 	}
-	
+
 	/**
 	 * Find the HTCP routing rule to use for a given URL.
-	 * @param $url string URL to match
-	 * @param $rules array Array of rules, see $wgHTCPMulticastRouting for format and behavior
+	 * @param string $url URL to match
+	 * @param array $rules Array of rules, see $wgHTCPMulticastRouting for format and behavior
 	 * @return mixed Element of $rules that matched, or false if nothing matched
 	 */
 	static function getRuleForURL( $url, $rules ) {
@@ -264,5 +266,4 @@ class SquidUpdate {
 		}
 		return false;
 	}
-	
 }
diff --git a/includes/cache/UserCache.php b/includes/cache/UserCache.php
index 6ec23669..bfbacfaa 100644
--- a/includes/cache/UserCache.php
+++ b/includes/cache/UserCache.php
@@ -45,7 +45,7 @@ class UserCache {
 	 * Get a property of a user based on their user ID
 	 *
 	 * @param $userId integer User ID
-	 * @param $prop string User property
+	 * @param string $prop User property
 	 * @return mixed The property or false if the user does not exist
 	 */
 	public function getProp( $userId, $prop ) {
@@ -60,9 +60,9 @@ class UserCache {
 
 	/**
 	 * Preloads user names for given list of users.
-	 * @param $userIds Array List of user IDs
-	 * @param $options Array Option flags; include 'userpage' and 'usertalk'
-	 * @param $caller String: the calling method
+	 * @param array $userIds List of user IDs
+	 * @param array $options Option flags; include 'userpage' and 'usertalk'
+	 * @param string $caller the calling method
 	 */
 	public function doQuery( array $userIds, $options = array(), $caller = '' ) {
 		wfProfileIn( __METHOD__ );
@@ -124,8 +124,8 @@ class UserCache {
 	 * Check if a cache type is in $options and was not loaded for this user
 	 *
 	 * @param $uid integer user ID
-	 * @param $type string Cache type
-	 * @param $options Array Requested cache types
+	 * @param string $type Cache type
+	 * @param array $options Requested cache types
 	 * @return bool
 	 */
 	protected function queryNeeded( $uid, $type, array $options ) {