+ $cache = ObjectCache::getMainWANInstance();
+ $cache->set( $key, $cacheVal, $this->fileExists ? 86400 * 7 : 86400 );
+ }
+
+ /**
+ * Purge the file object/metadata cache
+ */
+ function invalidateCache() {
+ $this->load();
+
+ $key = $this->getCacheKey();
+ if ( !$key ) {
+ return;
+ }
+
+ $cache = ObjectCache::getMainWANInstance();
+ $cache->delete( $key );