aggregations.py 文件源码

def _get_oldest_event_timestamp(self):
        """Search for the oldest event timestamp."""
        # Retrieve the oldest event in order to start aggregation
        # from there
        query_events = Search(
            using=self.client,
            index=self.event_index
        )[0:1].sort(
            {'timestamp': {'order': 'asc'}}
        )
        result = query_events.execute()
        # There might not be any events yet if the first event have been
        # indexed but the indices have not been refreshed yet.
        if len(result) == 0:
            return None
        return parser.parse(result[0]['timestamp'])