def _get_state_for_group_using_cache(
self,
cache: DictionaryCache[int, StateKey, str],
group: int,
state_filter: StateFilter,
) -> Tuple[MutableStateMap[str], bool]:
"""Checks if group is in cache. See `_get_state_for_groups`
Args:
cache: the state group cache to use
group: The state group to lookup
state_filter: The state filter used to fetch state from the database.
Returns:
2-tuple (`state_dict`, `got_all`).
`got_all` is a bool indicating if we successfully retrieved all
requests state from the cache, if False we need to query the DB for the
missing state.
"""
cache_entry = cache.get(group)
state_dict_ids = cache_entry.value
if cache_entry.full or state_filter.is_full():
# Either we have everything or want everything, either way
# `is_all` tells us whether we've gotten everything.
return state_filter.filter_state(state_dict_ids), cache_entry.full
# tracks whether any of our requested types are missing from the cache
missing_types = False
if state_filter.has_wildcards():
# We don't know if we fetched all the state keys for the types in
# the filter that are wildcards, so we have to assume that we may
# have missed some.
missing_types = True
else:
# There aren't any wild cards, so `concrete_types()` returns the
# complete list of event types we're wanting.
for key in state_filter.concrete_types():
if key not in state_dict_ids and key not in cache_entry.known_absent:
missing_types = True
break
return state_filter.filter_state(state_dict_ids), not missing_types
def _get_state_for_groups(self,
groups: Iterable[int],
state_filter: StateFilter = StateFilter.all()):
"""Gets the state at each of a list of state groups, optionally
filtering by type/state_key
Args:
groups: list of state groups for which we want
to get the state.
state_filter: The state filter used to fetch state
from the database.
Returns:
Deferred[Dict[int, StateMap[str]]]: Dict of state group to state map.
"""
member_filter, non_member_filter = state_filter.get_member_split()
# Now we look them up in the member and non-member caches
(
non_member_state,
incomplete_groups_nm,
) = yield self._get_state_for_groups_using_cache(
groups, self._state_group_cache, state_filter=non_member_filter)
(
member_state,
incomplete_groups_m,
) = yield self._get_state_for_groups_using_cache(
groups,
self._state_group_members_cache,
state_filter=member_filter)
state = dict(non_member_state)
for group in groups:
state[group].update(member_state[group])
# Now fetch any missing groups from the database
incomplete_groups = incomplete_groups_m | incomplete_groups_nm
if not incomplete_groups:
return state
cache_sequence_nm = self._state_group_cache.sequence
cache_sequence_m = self._state_group_members_cache.sequence
# Help the cache hit ratio by expanding the filter a bit
db_state_filter = state_filter.return_expanded()
group_to_state_dict = yield self._get_state_groups_from_groups(
list(incomplete_groups), state_filter=db_state_filter)
# Now lets update the caches
self._insert_into_cache(
group_to_state_dict,
db_state_filter,
cache_seq_num_members=cache_sequence_m,
cache_seq_num_non_members=cache_sequence_nm,
)
# And finally update the result dict, by filtering out any extra
# stuff we pulled out of the database.
for group, group_state_dict in iteritems(group_to_state_dict):
# We just replace any existing entries, as we will have loaded
# everything we need from the database anyway.
state[group] = state_filter.filter_state(group_state_dict)
return state
