Move function to LargeFileHelper

Signed-off-by: Lukas Reschke <lukas@statuscode.ch>

lib/private/Files/Storage/Local.php

@@ -179,7 +179,8 @@ public function filemtime($path) {
 			return false;
 		}
 		if (PHP_INT_SIZE === 4) {
-			return (int) exec ('stat -c %Y '. escapeshellarg ($fullPath));
+			$helper = new \OC\LargeFileHelper();
+			return $helper->getFileMtime($fullPath);
 		}
 		return filemtime($fullPath);
 	}

lib/private/LargeFileHelper.php

@@ -187,6 +187,20 @@ public function getFileSizeNative($filename) {
 		return $result;
 	}
 
+	/**
+	 * Returns the current mtime for $fullPath
+	 *
+	 * @param string $fullPath
+	 * @return int
+	 */
+	public function getFileMtime($fullPath) {
+		if (\OC_Helper::is_function_enabled('exec')) {
+			return $this->exec('stat -c %Y ' . escapeshellarg($fullPath));
+		}
+
+		return filemtime($fullPath);
+	}
+
 	protected function exec($cmd) {
 		$result = trim(exec($cmd));
 		return ctype_digit($result) ? 0 + $result : null;