diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index 986a20400c..cd9821c270 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -526,10 +526,23 @@ class StateGroupWorkerStore(SQLBaseStore):
@defer.inlineCallbacks
def _get_state_for_groups(self, groups, types=None):
- """Given list of groups returns dict of group -> list of state events
- with matching types. `types` is a list of `(type, state_key)`, where
- a `state_key` of None matches all state_keys. If `types` is None then
- all events are returned.
+ """Gets the state at each of a list of state groups, optionally
+ filtering by type/state_key
+
+ Args:
+ groups (iterable[int]): list of state groups for which we want
+ to get the state.
+ types (None|iterable[(str, None|str)]):
+ indicates the state type/keys required. If None, the whole
+ state is fetched and returned.
+
+ Otherwise, each entry should be a `(type, state_key)` tuple to
+ include in the response. A `state_key` of None is a wildcard
+ meaning that we require all state with that type.
+
+ Returns:
+ Deferred[dict[int, dict[(type, state_key), EventBase]]]
+ a dictionary mapping from state group to state dictionary.
"""
if types:
types = frozenset(types)
@@ -538,7 +551,7 @@ class StateGroupWorkerStore(SQLBaseStore):
if types is not None:
for group in set(groups):
state_dict_ids, _, got_all = self._get_some_state_from_cache(
- group, types
+ group, types,
)
results[group] = state_dict_ids
@@ -559,22 +572,40 @@ class StateGroupWorkerStore(SQLBaseStore):
# Okay, so we have some missing_types, lets fetch them.
cache_seq_num = self._state_group_cache.sequence
+ # the DictionaryCache knows if it has *all* the state, but
+ # does not know if it has all of the keys of a particular type,
+ # which makes wildcard lookups expensive unless we have a complete
+ # cache. Hence, if we are doing a wildcard lookup, populate the
+ # cache fully so that we can do an efficient lookup next time.
+
+ if types and any(k is None for (t, k) in types):
+ types_to_fetch = None
+ else:
+ types_to_fetch = types
+
group_to_state_dict = yield self._get_state_groups_from_groups(
- missing_groups, types
+ missing_groups, types_to_fetch,
)
- # Now we want to update the cache with all the things we fetched
- # from the database.
for group, group_state_dict in iteritems(group_to_state_dict):
state_dict = results[group]
- state_dict.update(group_state_dict)
+ # update the result, filtering by `types`.
+ if types:
+ for k, v in iteritems(group_state_dict):
+ (typ, _) = k
+ if k in types or (typ, None) in types:
+ state_dict[k] = v
+ else:
+ state_dict.update(group_state_dict)
+
+ # update the cache with all the things we fetched from the
+ # database.
self._state_group_cache.update(
cache_seq_num,
key=group,
- value=state_dict,
- full=(types is None),
- known_absent=types,
+ value=group_state_dict,
+ fetched_keys=types_to_fetch,
)
defer.returnValue(results)
@@ -681,7 +712,6 @@ class StateGroupWorkerStore(SQLBaseStore):
self._state_group_cache.sequence,
key=state_group,
value=dict(current_state_ids),
- full=True,
)
return state_group
diff --git a/synapse/util/caches/dictionary_cache.py b/synapse/util/caches/dictionary_cache.py
index bdc21e348f..95793d466d 100644
--- a/synapse/util/caches/dictionary_cache.py
+++ b/synapse/util/caches/dictionary_cache.py
@@ -107,29 +107,28 @@ class DictionaryCache(object):
self.sequence += 1
self.cache.clear()
- def update(self, sequence, key, value, full=False, known_absent=None):
+ def update(self, sequence, key, value, fetched_keys=None):
"""Updates the entry in the cache
Args:
sequence
- key
- value (dict): The value to update the cache with.
- full (bool): Whether the given value is the full dict, or just a
- partial subset there of. If not full then any existing entries
- for the key will be updated.
- known_absent (set): Set of keys that we know don't exist in the full
- dict.
+ key (K)
+ value (dict[X,Y]): The value to update the cache with.
+ fetched_keys (None|set[X]): All of the dictionary keys which were
+ fetched from the database.
+
+ If None, this is the complete value for key K. Otherwise, it
+ is used to infer a list of keys which we know don't exist in
+ the full dict.
"""
self.check_thread()
if self.sequence == sequence:
# Only update the cache if the caches sequence number matches the
# number that the cache had before the SELECT was started (SYN-369)
- if known_absent is None:
- known_absent = set()
- if full:
- self._insert(key, value, known_absent)
+ if fetched_keys is None:
+ self._insert(key, value, set())
else:
- self._update_or_insert(key, value, known_absent)
+ self._update_or_insert(key, value, fetched_keys)
def _update_or_insert(self, key, value, known_absent):
# We pop and reinsert as we need to tell the cache the size may have
|
