<?php
/**
- * File for BacklinkCache class
+ * 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
*/
/**
* Introduced by r47317
*
* @internal documentation reviewed on 18 Mar 2011 by hashar
- *
- * @author Tim Starling
- * @copyright © 2009, Tim Starling, Domas Mituzas
- * @copyright © 2010, Max Sem
- * @copyright © 2011, Ashar Voultoiz
*/
class BacklinkCache {
+ /** @var ProcessCacheLRU */
+ protected static $cache;
/**
* Multi dimensions array representing batches. Keys are:
/**
* Create a new BacklinkCache
- * @param Title $title : Title object to create a backlink cache for.
+ *
+ * @param Title $title : Title object to create a backlink cache for
*/
- function __construct( $title ) {
+ 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' );
/**
* Get the slave connection to the database
* When non existing, will initialize the connection.
- * @return Database object
+ * @return DatabaseBase object
*/
protected function getDB() {
if ( !isset( $this->db ) ) {
return $ta;
}
- /**
- * Get the distant backtemplatelinks for the table globaltemplatelinks. Cached in process memory only.
- * @return ResultWrapper list of distant pages that use the local title
- */
- public function getDistantTemplateLinks( ) {
- global $wgGlobalDatabase, $wgLocalInterwiki;
-
- $dbr = wfGetDB( DB_SLAVE, array(), $wgGlobalDatabase );
- $res = $dbr->select(
- array( 'globaltemplatelinks', 'globalinterwiki' ),
- array( 'gtl_from_wiki', 'gtl_from_page', 'gtl_from_title', 'giw_prefix' ),
- array( 'gtl_to_prefix' => $wgLocalInterwiki, 'gtl_to_title' => $this->title->getDBkey( ) ),
- __METHOD__,
- null,
- array( 'gtl_from_wiki = giw_wikiid' )
- );
- return $res;
- }
-
/**
* Get the field name prefix for a given table
* @param $table String
+ * @throws MWException
+ * @return null|string
*/
protected function getPrefix( $table ) {
static $prefixes = array(
'categorylinks' => 'cl',
'templatelinks' => 'tl',
'redirect' => 'rd',
- 'globaltemplatelinks' => 'gtl',
);
if ( isset( $prefixes[$table] ) ) {
* 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 );
default:
$conds = null;
wfRunHooks( 'BacklinkCacheGetConditions', array( $table, $this->title, &$conds ) );
- if( !$conds )
+ if( !$conds ) {
throw new MWException( "Invalid table \"$table\" in " . __CLASS__ );
+ }
}
return $conds;
* 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 ) {