def copy_file(self, path, prefixed_path, source_storage):
        """
        Appends path to task queue if threads are enabled, otherwise copies
        the file with a blocking call.
        """
        args = (path, prefixed_path, source_storage)
        if settings.threads:
            self.tasks.append(args)
        else:
            self.do_copy_file(args)
Appends path to task queue if threads are enabled, otherwise copies
        the file with a blocking call.