Only notify the target of a membership event (#14971)

* Only notify the target of a membership event

Naughty, but should be a big speedup in large rooms
This commit is contained in:
David Robertson 2023-02-06 11:29:51 +00:00 committed by GitHub
parent 6e6edea6c1
commit b3bf58a8a5
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
2 changed files with 31 additions and 8 deletions

1
changelog.d/14971.misc Normal file
View file

@ -0,0 +1 @@
Improve performance of joining and leaving large rooms with many local users.

View file

@ -142,15 +142,34 @@ class BulkPushRuleEvaluator:
Returns:
Mapping of user ID to their push rules.
"""
# We get the users who may need to be notified by first fetching the
# local users currently in the room, finding those that have push rules,
# and *then* checking which users are actually allowed to see the event.
#
# The alternative is to first fetch all users that were joined at the
# event, but that requires fetching the full state at the event, which
# may be expensive for large rooms with few local users.
# If this is a membership event, only calculate push rules for the target.
# While it's possible for users to configure push rules to respond to such an
# event, in practise nobody does this. At the cost of violating the spec a
# little, we can skip fetching a huge number of push rules in large rooms.
# This helps make joins and leaves faster.
if event.type == EventTypes.Member:
local_users = []
# We never notify a user about their own actions. This is enforced in
# `_action_for_event_by_user` in the loop over `rules_by_user`, but we
# do the same check here to avoid unnecessary DB queries.
if event.sender != event.state_key and self.hs.is_mine_id(event.state_key):
# Check the target is in the room, to avoid notifying them of
# e.g. a pre-emptive ban.
target_already_in_room = await self.store.check_local_user_in_room(
event.state_key, event.room_id
)
if target_already_in_room:
local_users = [event.state_key]
else:
# We get the users who may need to be notified by first fetching the
# local users currently in the room, finding those that have push rules,
# and *then* checking which users are actually allowed to see the event.
#
# The alternative is to first fetch all users that were joined at the
# event, but that requires fetching the full state at the event, which
# may be expensive for large rooms with few local users.
local_users = await self.store.get_local_users_in_room(event.room_id)
local_users = await self.store.get_local_users_in_room(event.room_id)
# Filter out appservice users.
local_users = [
@ -167,6 +186,9 @@ class BulkPushRuleEvaluator:
local_users = list(local_users)
local_users.append(invited)
if not local_users:
return {}
rules_by_user = await self.store.bulk_get_push_rules(local_users)
logger.debug("Users in room: %s", local_users)