diff options
Diffstat (limited to 'synapse/util')
| -rw-r--r-- | synapse/util/caches/stream_change_cache.py | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/synapse/util/caches/stream_change_cache.py b/synapse/util/caches/stream_change_cache.py index 38dc3f501e..e54f80d76e 100644 --- a/synapse/util/caches/stream_change_cache.py +++ b/synapse/util/caches/stream_change_cache.py @@ -14,12 +14,13 @@ # limitations under the License. import logging -from typing import Dict, Iterable, List, Mapping, Optional, Set +from typing import Dict, FrozenSet, List, Mapping, Optional, Set, Union from six import integer_types from sortedcontainers import SortedDict +from synapse.types import Collection from synapse.util import caches logger = logging.getLogger(__name__) @@ -85,8 +86,8 @@ class StreamChangeCache: return False def get_entities_changed( - self, entities: Iterable[EntityType], stream_pos: int - ) -> Set[EntityType]: + self, entities: Collection[EntityType], stream_pos: int + ) -> Union[Set[EntityType], FrozenSet[EntityType]]: """ Returns subset of entities that have had new things since the given position. Entities unknown to the cache will be returned. If the @@ -94,7 +95,17 @@ class StreamChangeCache: """ changed_entities = self.get_all_entities_changed(stream_pos) if changed_entities is not None: - result = set(changed_entities).intersection(entities) + # We now do an intersection, trying to do so in the most efficient + # way possible (some of these sets are *large*). First check in the + # given iterable is already set that we can reuse, otherwise we + # create a set of the *smallest* of the two iterables and call + # `intersection(..)` on it (this can be twice as fast as the reverse). + if isinstance(entities, (set, frozenset)): + result = entities.intersection(changed_entities) + elif len(changed_entities) < len(entities): + result = set(changed_entities).intersection(entities) + else: + result = set(entities).intersection(changed_entities) self.metrics.inc_hits() else: result = set(entities) |