}
/**
- * Check if a file can be created at a given storage path.
- * FS backends should check if the parent directory exists and the file is writable.
+ * Check if a file can be created or changed at a given storage path.
+ * FS backends should check if the parent directory exists, files can be
+ * written under it, and that any file already there is writable.
* Backends using key/value stores should check if the container exists.
*
* @param $storagePath string
*/
abstract protected function doGetLocalCopyMulti( array $params );
+ /**
+ * @see FileBackend::getFileHttpUrl()
+ * @return string|null
+ */
+ public function getFileHttpUrl( array $params ) {
+ return null; // not supported
+ }
+
/**
* @see FileBackend::streamFile()
* @return Status