presto.py 文件源码

def poll(self):
        """Poll for and return the raw status data provided by the Presto REST API.

        :returns: dict -- JSON status information or ``None`` if the query is done
        :raises: ``ProgrammingError`` when no query has been started

        .. note::
            This is not a part of DB-API.
        """
        if self._state == self._STATE_NONE:
            raise ProgrammingError("No query yet")
        if self._nextUri is None:
            assert self._state == self._STATE_FINISHED, "Should be finished if nextUri is None"
            raise Return(None)
        request = HTTPRequest(self._nextUri)
        client = AsyncHTTPClient(max_clients=512)
        response = yield client.fetch(request)
        self._process_response(response)
        raise Return(json_decode(response.body))