1 files changed, 59 insertions, 9 deletions

diff --git a/includes/cache/LinkCache.php b/includes/cache/LinkCache.php
index 0e41e265..54de1989 100644
--- a/includes/cache/LinkCache.php
+++ b/includes/cache/LinkCache.php
@@ -35,18 +35,44 @@ class LinkCache {
 	private $mGoodLinkFields = array();
 	private $mBadLinks = array();
 	private $mForUpdate = false;
+	private $useDatabase = true;
 
 	/**
-	 * Get an instance of this class
+	 * @var LinkCache
+	 */
+	protected static $instance;
+
+	/**
+	 * Get an instance of this class.
 	 *
 	 * @return LinkCache
 	 */
 	static function &singleton() {
-		static $instance;
-		if ( !isset( $instance ) ) {
-			$instance = new LinkCache;
+		if ( self::$instance ) {
+			return self::$instance;
 		}
-		return $instance;
+		self::$instance = new LinkCache;
+		return self::$instance;
+	}
+
+	/**
+	 * Destroy the singleton instance, a new one will be created next time
+	 * singleton() is called.
+	 * @since 1.22
+	 */
+	static function destroySingleton() {
+		self::$instance = null;
+	}
+
+	/**
+	 * Set the singleton instance to a given object.
+	 * Since we do not have an interface for LinkCache, you have to be sure the
+	 * given object implements all the LinkCache public methods.
+	 * @param LinkCache $instance
+	 * @since 1.22
+	 */
+	static function setSingleton( LinkCache $instance ) {
+		self::$instance = $instance;
 	}
 
 	/**
@@ -156,8 +182,13 @@ class LinkCache {
 		unset( $this->mGoodLinkFields[$dbkey] );
 	}
 
-	public function getGoodLinks() { return $this->mGoodLinks; }
-	public function getBadLinks() { return array_keys( $this->mBadLinks ); }
+	public function getGoodLinks() {
+		return $this->mGoodLinks;
+	}
+
+	public function getBadLinks() {
+		return array_keys( $this->mBadLinks );
+	}
 
 	/**
 	 * Add a title to the link cache, return the page_id or zero if non-existent
@@ -167,7 +198,7 @@ class LinkCache {
 	 */
 	public function addLink( $title ) {
 		$nt = Title::newFromDBkey( $title );
-		if( $nt ) {
+		if ( $nt ) {
 			return $this->addLinkObj( $nt );
 		} else {
 			return 0;
@@ -175,6 +206,19 @@ class LinkCache {
 	}
 
 	/**
+	 * Enable or disable database use.
+	 * @since 1.22
+	 * @param $value Boolean
+	 * @return Boolean
+	 */
+	public function useDatabase( $value = null ) {
+		if ( $value !== null ) {
+			$this->useDatabase = (bool)$value;
+		}
+		return $this->useDatabase;
+	}
+
+	/**
 	 * Add a title to the link cache, return the page_id or zero if non-existent
 	 *
 	 * @param $nt Title object to add
@@ -201,6 +245,10 @@ class LinkCache {
 			return 0;
 		}
 
+		if( !$this->useDatabase ) {
+			return 0;
+		}
+
 		# Some fields heavily used for linking...
 		if ( $this->mForUpdate ) {
 			$db = wfGetDB( DB_MASTER );
@@ -215,7 +263,9 @@ class LinkCache {
 		}
 
 		$f = array( 'page_id', 'page_len', 'page_is_redirect', 'page_latest' );
-		if ( $wgContentHandlerUseDB ) $f[] = 'page_content_model';
+		if ( $wgContentHandlerUseDB ) {
+			$f[] = 'page_content_model';
+		}
 
 		$s = $db->selectRow( 'page', $f,
 			array( 'page_namespace' => $nt->getNamespace(), 'page_title' => $nt->getDBkey() ),