Refactor to calculate state delta outside transaction

This commit is contained in:
Erik Johnston 2017-01-23 14:51:33 +00:00
parent 5d2134d485
commit c77b24c092

View file

@ -284,71 +284,37 @@ class EventsStore(SQLBaseStore):
new_forward_extremeties = {}
current_state_for_room = {}
if not backfilled:
# Work out the new "current state" for each room.
# We do this by working out what the new extremities are and then
# calculating the state from that.
events_by_room = {}
for event, context in chunk:
events_by_room.setdefault(event.room_id, []).append(
(event, context)
)
for room_id, ev_ctx_rm in events_by_room.items():
# Work out new extremities by recursively adding and removing
# the new events.
latest_event_ids = yield self.get_latest_event_ids_in_room(
room_id
)
new_latest_event_ids = yield self._calculate_new_extremeties(
room_id, [ev for ev, _ in ev_ctx_rm]
)
if new_latest_event_ids == set(latest_event_ids):
# No change in extremities, so no change in state
continue
new_forward_extremeties[room_id] = new_latest_event_ids
# Now we need to work out the different state sets for
# each state extremities
state_sets = []
missing_event_ids = []
was_updated = False
for event_id in new_latest_event_ids:
# First search in the list of new events we're adding,
# and then use the current state from that
for ev, ctx in ev_ctx_rm:
if event_id == ev.event_id:
if ctx.current_state_ids is None:
raise Exception("Unknown current state")
state_sets.append(ctx.current_state_ids)
if ctx.delta_ids or hasattr(ev, "state_key"):
was_updated = True
break
else:
# If we couldn't find it, then we'll need to pull
# the state from the database
was_updated = True
missing_event_ids.append(event_id)
if missing_event_ids:
# Now pull out the state for any missing events from DB
event_to_groups = yield self._get_state_group_for_events(
missing_event_ids,
with Measure(self._clock, "_calculate_state_and_extrem"):
# Work out the new "current state" for each room.
# We do this by working out what the new extremities are and then
# calculating the state from that.
events_by_room = {}
for event, context in chunk:
events_by_room.setdefault(event.room_id, []).append(
(event, context)
)
groups = set(event_to_groups.values())
group_to_state = yield self._get_state_for_groups(groups)
state_sets.extend(group_to_state.values())
if not new_latest_event_ids or was_updated:
current_state_for_room[room_id] = yield resolve_events(
state_sets,
state_map_factory=lambda ev_ids: self.get_events(
ev_ids, get_prev_content=False, check_redacted=False,
),
for room_id, ev_ctx_rm in events_by_room.items():
# Work out new extremities by recursively adding and removing
# the new events.
latest_event_ids = yield self.get_latest_event_ids_in_room(
room_id
)
new_latest_event_ids = yield self._calculate_new_extremeties(
room_id, [ev for ev, _ in ev_ctx_rm]
)
if new_latest_event_ids == set(latest_event_ids):
# No change in extremities, so no change in state
continue
new_forward_extremeties[room_id] = new_latest_event_ids
state = yield self._calculate_state_delta(
room_id, ev_ctx_rm, new_latest_event_ids
)
if state:
current_state_for_room[room_id] = state
yield self.runInteraction(
"persist_events",
@ -405,6 +371,91 @@ class EventsStore(SQLBaseStore):
defer.returnValue(new_latest_event_ids)
@defer.inlineCallbacks
def _calculate_state_delta(self, room_id, events_context, new_latest_event_ids):
"""Calculate the new state deltas for a room.
Assumes that we are only persisting events for one room at a time.
Returns:
2-tuple (to_delete, to_insert) where both are state dicts, i.e.
(type, state_key) -> event_id. `to_delete` are the entreis to
first be deleted from current_state_events, `to_insert` are entries
to insert.
May return None if there are no changes to be applied.
"""
# Now we need to work out the different state sets for
# each state extremities
state_sets = []
missing_event_ids = []
was_updated = False
for event_id in new_latest_event_ids:
# First search in the list of new events we're adding,
# and then use the current state from that
for ev, ctx in events_context:
if event_id == ev.event_id:
if ctx.current_state_ids is None:
raise Exception("Unknown current state")
state_sets.append(ctx.current_state_ids)
if ctx.delta_ids or hasattr(ev, "state_key"):
was_updated = True
break
else:
# If we couldn't find it, then we'll need to pull
# the state from the database
was_updated = True
missing_event_ids.append(event_id)
if missing_event_ids:
# Now pull out the state for any missing events from DB
event_to_groups = yield self._get_state_group_for_events(
missing_event_ids,
)
groups = set(event_to_groups.values())
group_to_state = yield self._get_state_for_groups(groups)
state_sets.extend(group_to_state.values())
if not new_latest_event_ids:
current_state = {}
elif was_updated:
current_state = yield resolve_events(
state_sets,
state_map_factory=lambda ev_ids: self.get_events(
ev_ids, get_prev_content=False, check_redacted=False,
),
)
else:
return
existing_state_rows = yield self._simple_select_list(
table="current_state_events",
keyvalues={"room_id": room_id},
retcols=["event_id", "type", "state_key"],
desc="_calculate_state_delta",
)
existing_events = set(row["event_id"] for row in existing_state_rows)
new_events = set(ev_id for ev_id in current_state.itervalues())
changed_events = existing_events ^ new_events
if not changed_events:
return
to_delete = {
(row["type"], row["state_key"]): row["event_id"]
for row in existing_state_rows
if row["event_id"] in changed_events
}
events_to_insert = (new_events - existing_events)
to_insert = {
key: ev_id for key, ev_id in current_state.iteritems()
if ev_id in events_to_insert
}
defer.returnValue((to_delete, to_insert))
@defer.inlineCallbacks
def get_event(self, event_id, check_redacted=True,
get_prev_content=False, allow_rejected=False,
@ -475,32 +526,13 @@ class EventsStore(SQLBaseStore):
database before insertion. This is useful when retrying due to IntegrityError.
"""
max_stream_order = events_and_contexts[-1][0].internal_metadata.stream_ordering
for room_id, current_state in current_state_for_room.iteritems():
existing_state_rows = self._simple_select_list_txn(
txn,
table="current_state_events",
keyvalues={"room_id": room_id},
retcols=["event_id", "type", "state_key"],
)
# Figure out what has changed (if anything). Then we simply delete
# and readd the keys that have been changed.
# This saves us from deleting and reinserting thousands of rows for
# large rooms.
existing_events = set(row["event_id"] for row in existing_state_rows)
new_events = set(ev_id for ev_id in current_state.itervalues())
changed_events = existing_events ^ new_events
if changed_events:
for room_id, current_state_tuple in current_state_for_room.iteritems():
to_delete, to_insert = current_state_tuple
txn.executemany(
"DELETE FROM current_state_events WHERE event_id = ?",
[(ev_id,) for ev_id in changed_events],
[(ev_id,) for ev_id in to_delete.itervalues()],
)
events_to_insert = (new_events - existing_events)
to_insert = [
(key, ev_id) for key, ev_id in current_state.iteritems()
if ev_id in events_to_insert
]
self._simple_insert_many_txn(
txn,
table="current_state_events",
@ -511,7 +543,7 @@ class EventsStore(SQLBaseStore):
"type": key[0],
"state_key": key[1],
}
for key, ev_id in to_insert
for key, ev_id in to_insert.iteritems()
],
)
@ -523,13 +555,12 @@ class EventsStore(SQLBaseStore):
# and which we have added, then we invlidate the caches for all
# those users.
members_changed = set(
row["state_key"] for row in existing_state_rows
if row["event_id"] in changed_events
and row["type"] == EventTypes.Member
state_key for ev_type, state_key in to_delete.iterkeys()
if ev_type == EventTypes.Member
)
members_changed.update(
key[1] for key, event_id in to_insert
if key[0] == EventTypes.Member
state_key for ev_type, state_key in to_insert.iterkeys()
if ev_type == EventTypes.Member
)
for member in members_changed: