Get size of filename

def _query(self, filename):
        """Get size of filename"""
        #  - Query metadata of one file
        #  - Return a dict with a 'size' key, and a file size value (-1 for not found)
        #  - Retried if an exception is thrown
        log.Info('Querying size of %s' % filename)
        from jottalib.JFS import JFSNotFoundError, JFSIncompleteFile
        remote_path = posixpath.join(self.folder.path, filename)
        try:
            remote_file = self.client.getObject(remote_path)
        except JFSNotFoundError:
            return {'size': -1}
        return {
            'size': remote_file.size,
        }