diff options
Diffstat (limited to 'synapse/util/caches/stream_change_cache.py')
| -rw-r--r-- | synapse/util/caches/stream_change_cache.py | 62 |
1 files changed, 34 insertions, 28 deletions
diff --git a/synapse/util/caches/stream_change_cache.py b/synapse/util/caches/stream_change_cache.py index a7fe0397fa..8637867c6d 100644 --- a/synapse/util/caches/stream_change_cache.py +++ b/synapse/util/caches/stream_change_cache.py @@ -13,12 +13,11 @@ # See the License for the specific language governing permissions and # limitations under the License. -from synapse.util.caches import register_cache, CACHE_SIZE_FACTOR - - -from blist import sorteddict import logging +from sortedcontainers import SortedDict + +from synapse.util import caches logger = logging.getLogger(__name__) @@ -32,16 +31,18 @@ class StreamChangeCache(object): entities that may have changed since that position. If position key is too old then the cache will simply return all given entities. """ - def __init__(self, name, current_stream_pos, max_size=10000, prefilled_cache={}): - self._max_size = int(max_size * CACHE_SIZE_FACTOR) + + def __init__(self, name, current_stream_pos, max_size=10000, prefilled_cache=None): + self._max_size = int(max_size * caches.CACHE_SIZE_FACTOR) self._entity_to_key = {} - self._cache = sorteddict() + self._cache = SortedDict() self._earliest_known_stream_pos = current_stream_pos self.name = name - self.metrics = register_cache("cache", self.name, self._cache) + self.metrics = caches.register_cache("cache", self.name, self._cache) - for entity, stream_pos in prefilled_cache.items(): - self.entity_has_changed(entity, stream_pos) + if prefilled_cache: + for entity, stream_pos in prefilled_cache.items(): + self.entity_has_changed(entity, stream_pos) def has_entity_changed(self, entity, stream_pos): """Returns True if the entity may have been updated since stream_pos @@ -65,22 +66,26 @@ class StreamChangeCache(object): return False def get_entities_changed(self, entities, stream_pos): - """Returns subset of entities that have had new things since the - given position. If the position is too old it will just return the given list. + """ + Returns subset of entities that have had new things since the given + position. Entities unknown to the cache will be returned. If the + position is too old it will just return the given list. """ assert type(stream_pos) is int if stream_pos >= self._earliest_known_stream_pos: - keys = self._cache.keys() - i = keys.bisect_right(stream_pos) + not_known_entities = set(entities) - set(self._entity_to_key) - result = set( - self._cache[k] for k in keys[i:] - ).intersection(entities) + result = ( + {self._cache[k] for k in self._cache.islice( + start=self._cache.bisect_right(stream_pos))} + .intersection(entities) + .union(not_known_entities) + ) self.metrics.inc_hits() else: - result = entities + result = set(entities) self.metrics.inc_misses() return result @@ -90,12 +95,13 @@ class StreamChangeCache(object): """ assert type(stream_pos) is int + if not self._cache: + # If we have no cache, nothing can have changed. + return False + if stream_pos >= self._earliest_known_stream_pos: self.metrics.inc_hits() - keys = self._cache.keys() - i = keys.bisect_right(stream_pos) - - return i < len(keys) + return self._cache.bisect_right(stream_pos) < len(self._cache) else: self.metrics.inc_misses() return True @@ -107,10 +113,8 @@ class StreamChangeCache(object): assert type(stream_pos) is int if stream_pos >= self._earliest_known_stream_pos: - keys = self._cache.keys() - i = keys.bisect_right(stream_pos) - - return [self._cache[k] for k in keys[i:]] + return [self._cache[k] for k in self._cache.islice( + start=self._cache.bisect_right(stream_pos))] else: return None @@ -129,8 +133,10 @@ class StreamChangeCache(object): self._entity_to_key[entity] = stream_pos while len(self._cache) > self._max_size: - k, r = self._cache.popitem() - self._earliest_known_stream_pos = max(k, self._earliest_known_stream_pos) + k, r = self._cache.popitem(0) + self._earliest_known_stream_pos = max( + k, self._earliest_known_stream_pos, + ) self._entity_to_key.pop(r, None) def get_max_pos_of_last_change(self, entity): |