diff options
Diffstat (limited to 'synapse/state')
| -rw-r--r-- | synapse/state/__init__.py | 68 |
1 files changed, 53 insertions, 15 deletions
diff --git a/synapse/state/__init__.py b/synapse/state/__init__.py index e3faa52cd6..87ccd52f0a 100644 --- a/synapse/state/__init__.py +++ b/synapse/state/__init__.py @@ -14,7 +14,7 @@ # limitations under the License. import heapq import logging -from collections import defaultdict +from collections import ChainMap, defaultdict from typing import ( TYPE_CHECKING, Any, @@ -92,8 +92,11 @@ class _StateCacheEntry: prev_group: Optional[int] = None, delta_ids: Optional[StateMap[str]] = None, ): - if state is None and state_group is None: - raise Exception("Either state or state group must be not None") + if state is None and state_group is None and prev_group is None: + raise Exception("One of state, state_group or prev_group must be not None") + + if prev_group is not None and delta_ids is None: + raise Exception("If prev_group is set so must delta_ids") # A map from (type, state_key) to event_id. # @@ -120,18 +123,48 @@ class _StateCacheEntry: if self._state is not None: return self._state - assert self.state_group is not None + if self.state_group is not None: + return await state_storage.get_state_ids_for_group( + self.state_group, state_filter + ) + + assert self.prev_group is not None and self.delta_ids is not None - return await state_storage.get_state_ids_for_group( - self.state_group, state_filter + prev_state = await state_storage.get_state_ids_for_group( + self.prev_group, state_filter ) + # ChainMap expects MutableMapping, but since we're using it immutably + # its safe to give it immutable maps. + return ChainMap(self.delta_ids, prev_state) # type: ignore[arg-type] + + def set_state_group(self, state_group: int) -> None: + """Update the state group assigned to this state (e.g. after we've + persisted it). + + Note: this will cause the cache entry to drop any stored state. + """ + + self.state_group = state_group + + # We clear out the state as we know longer need to explicitly keep it in + # the `state_cache` (as the store state group cache will do that). + self._state = None + def __len__(self) -> int: - # The len should is used to estimate how large this cache entry is, for - # cache eviction purposes. This is why if `self.state` is None it's fine - # to return 1. + # The len should be used to estimate how large this cache entry is, for + # cache eviction purposes. This is why it's fine to return 1 if we're + # not storing any state. + + length = 0 - return len(self._state) if self._state else 1 + if self._state: + length += len(self._state) + + if self.delta_ids: + length += len(self.delta_ids) + + return length or 1 # Make sure its not 0. class StateHandler: @@ -320,7 +353,7 @@ class StateHandler: current_state_ids=state_ids_before_event, ) ) - entry.state_group = state_group_before_event + entry.set_state_group(state_group_before_event) else: state_group_before_event = entry.state_group @@ -747,7 +780,7 @@ def _make_state_cache_entry( old_state_event_ids = set(state.values()) if new_state_event_ids == old_state_event_ids: # got an exact match. - return _StateCacheEntry(state=new_state, state_group=sg) + return _StateCacheEntry(state=None, state_group=sg) # TODO: We want to create a state group for this set of events, to # increase cache hits, but we need to make sure that it doesn't @@ -769,9 +802,14 @@ def _make_state_cache_entry( prev_group = old_group delta_ids = n_delta_ids - return _StateCacheEntry( - state=new_state, state_group=None, prev_group=prev_group, delta_ids=delta_ids - ) + if prev_group is not None: + # If we have a prev group and deltas then we can drop the new state from + # the cache (to reduce memory usage). + return _StateCacheEntry( + state=None, state_group=None, prev_group=prev_group, delta_ids=delta_ids + ) + else: + return _StateCacheEntry(state=new_state, state_group=None) @attr.s(slots=True, auto_attribs=True) |