Make Sites::singleton() actually return a singleton.

Sites::singleton() was returning a new instance for every call,
rendering in-process caching ineffective. This was causing extreme
slowness on some configurations (about factor 100).

Change-Id: I1e28afea8710b44542c55db150ad37518a5a5df1

diff --git a/includes/site/SiteSQLStore.php b/includes/site/SiteSQLStore.php
index a79c8c5..c462057 100644 (file)
--- a/includes/site/SiteSQLStore.php
+++ b/includes/site/SiteSQLStore.php
@@ -466,7 +466,13 @@ class Sites extends SiteSQLStore {
         * @return SiteStore
         */
        public static function singleton() {
-               return new static();
+               static $singleton;
+
+               if ( $singleton === null ) {
+                       $singleton = new static();
+               }
+
+               return $singleton;
        }
 
        /**