Merge pull request #1944 from owncloud/query-caching-upgrade

Disable prepared query caching while doing an upgrade

core/ajax/update.php

@@ -4,6 +4,7 @@ $RUNTIME_NOAPPS = true;
 require_once '../../lib/base.php';
 
 if (OC::checkUpgrade(false)) {
+	\OC_DB::enableCaching(false);
 	$updateEventSource = new OC_EventSource();
 	$watcher = new UpdateWatcher($updateEventSource);
 	OC_Hook::connect('update', 'success', $watcher, 'success');
@@ -64,4 +65,4 @@ class UpdateWatcher {
 		$this->eventSource->close();
 	}
 
-}
+}

lib/db.php

@@ -42,6 +42,7 @@ class OC_DB {
 	const BACKEND_MDB2=1;
 
 	static private $preparedQueries = array();
+	static private $cachingEnabled = true;
 
 	/**
 	 * @var MDB2_Driver_Common
@@ -356,7 +357,7 @@ class OC_DB {
 				}
 			}
 		} else {
-			if (isset(self::$preparedQueries[$query])) {
+			if (isset(self::$preparedQueries[$query]) and self::$cachingEnabled) {
 				return self::$preparedQueries[$query];
 			}
 		}
@@ -382,7 +383,7 @@ class OC_DB {
 			}
 			$result=new PDOStatementWrapper($result);
 		}
-		if (is_null($limit) || $limit == -1) {
+		if ((is_null($limit) || $limit == -1) and self::$cachingEnabled ) {
 			self::$preparedQueries[$rawQuery] = $result;
 		}
 		return $result;
@@ -915,6 +916,16 @@ class OC_DB {
 		}
 		return $msg;
 	}
+
+	/**
+	 * @param bool $enabled
+	 */
+	static public function enableCaching($enabled) {
+		if (!$enabled) {
+			self::$preparedQueries = array();
+		}
+		self::$cachingEnabled = $enabled;
+	}
 }
 
 /**