First step of making user_rooms_intersect() faster - implement in intersection logic in Python code terms of a DB query that is cacheable per user

This commit is contained in:
Paul "LeoNerd" Evans 2015-02-11 15:53:56 +00:00
parent 6370cffbbf
commit 7be0f6594e

View file

@ -240,28 +240,30 @@ class RoomMemberStore(SQLBaseStore):
results = self._parse_events_txn(txn, rows)
return results
@defer.inlineCallbacks
def user_rooms_intersect(self, user_id_list):
""" Checks whether all the users whose IDs are given in a list share a
room.
This is a "hot path" function that's called a lot, e.g. by presence for
generating the event stream.
"""
def interaction(txn):
user_list_clause = " OR ".join(["m.user_id = ?"] * len(user_id_list))
sql = (
"SELECT m.room_id FROM room_memberships as m "
"INNER JOIN current_state_events as c "
"ON m.event_id = c.event_id "
"WHERE m.membership = 'join' "
"AND (%(clause)s) "
# TODO(paul): We've got duplicate rows in the database somewhere
# so we have to DISTINCT m.user_id here
"GROUP BY m.room_id HAVING COUNT(DISTINCT m.user_id) = ?"
) % {"clause": user_list_clause}
if len(user_id_list) < 2:
defer.returnValue(True)
args = list(user_id_list)
args.append(len(user_id_list))
deferreds = [
self.get_rooms_for_user_where_membership_is(
u, membership_list=[Membership.JOIN],
)
for u in user_id_list
]
txn.execute(sql, args)
results = yield defer.DeferredList(deferreds)
return len(txn.fetchall()) > 0
# A list of sets of strings giving room IDs for each user
room_id_lists = [set([r.room_id for r in result[1]]) for result in results]
return self.runInteraction("user_rooms_intersect", interaction)
# There isn't a setintersection(*list_of_sets)
ret = len(room_id_lists.pop(0).intersection(*room_id_lists)) > 0
defer.returnValue(ret)