use propagator batching in the scanner

lib/private/Files/Utils/Scanner.php

@@ -138,7 +138,9 @@ public function backgroundScan($dir) {
 				$this->triggerPropagator($storage, $path);
 			});
 
+			$storage->getPropagator()->beginBatch();
 			$scanner->backgroundScan();
+			$storage->getPropagator()->commitBatch();
 		}
 	}
 
@@ -182,12 +184,14 @@ public function scan($dir = '') {
 				$this->db->beginTransaction();
 			}
 			try {
+				$storage->getPropagator()->beginBatch();
 				$scanner->scan($relativePath, \OC\Files\Cache\Scanner::SCAN_RECURSIVE, \OC\Files\Cache\Scanner::REUSE_ETAG | \OC\Files\Cache\Scanner::REUSE_SIZE);
 				$cache = $storage->getCache();
 				if ($cache instanceof Cache) {
 					// only re-calculate for the root folder we scanned, anything below that is taken care of by the scanner
 					$cache->correctFolderSize($relativePath);
 				}
+				$storage->getPropagator()->commitBatch();
 			} catch (StorageNotAvailableException $e) {
 				$this->logger->error('Storage ' . $storage->getId() . ' not available');
 				$this->logger->logException($e);