From a1e0d316ea354fce07939073d9afc9c5d1013939 Mon Sep 17 00:00:00 2001 From: Mark Haines Date: Wed, 6 Apr 2016 13:05:19 +0100 Subject: Move _get_cache_dict into the SQLBaseStore --- synapse/storage/_base.py | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) (limited to 'synapse/storage/_base.py') diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py index b75b79df36..04d7fcf6d6 100644 --- a/synapse/storage/_base.py +++ b/synapse/storage/_base.py @@ -816,6 +816,40 @@ class SQLBaseStore(object): self._next_stream_id += 1 return i + def _get_cache_dict(self, db_conn, table, entity_column, stream_column, + max_value): + # Fetch a mapping of room_id -> max stream position for "recent" rooms. + # It doesn't really matter how many we get, the StreamChangeCache will + # do the right thing to ensure it respects the max size of cache. + sql = ( + "SELECT %(entity)s, MAX(%(stream)s) FROM %(table)s" + " WHERE %(stream)s > ? - 100000" + " GROUP BY %(entity)s" + ) % { + "table": table, + "entity": entity_column, + "stream": stream_column, + } + + sql = self.database_engine.convert_param_style(sql) + + txn = db_conn.cursor() + txn.execute(sql, (int(max_value),)) + rows = txn.fetchall() + txn.close() + + cache = { + row[0]: int(row[1]) + for row in rows + } + + if cache: + min_val = min(cache.values()) + else: + min_val = max_value + + return cache, min_val + class _RollbackButIsFineException(Exception): """ This exception is used to rollback a transaction without implying -- cgit 1.4.1