Add a DB index to figure out past state at a stream ordering in a room

This commit is contained in:
Erik Johnston 2016-09-14 16:09:32 +01:00
parent 3e6e8a1c03
commit ed992ae6ba
2 changed files with 118 additions and 0 deletions

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@ -16,6 +16,7 @@
from twisted.internet import defer
from ._base import SQLBaseStore
from synapse.api.errors import StoreError
from synapse.util.caches.descriptors import cached
from unpaddedbase64 import encode_base64
@ -36,6 +37,13 @@ class EventFederationStore(SQLBaseStore):
and backfilling from another server respectively.
"""
def __init__(self, hs):
super(EventFederationStore, self).__init__(hs)
hs.get_clock().looping_call(
self._delete_old_forward_extrem_cache, 60 * 60 * 1000
)
def get_auth_chain(self, event_ids):
return self.get_auth_chain_ids(event_ids).addCallback(self._get_events)
@ -270,6 +278,37 @@ class EventFederationStore(SQLBaseStore):
]
)
# We now insert into stream_ordering_to_exterm a mapping from room_id,
# new stream_ordering to new forward extremeties in the room.
# This allows us to later efficiently look up the forward extremeties
# for a room before a given stream_ordering
max_stream_ord = max(
ev.internal_metadata.stream_ordering for ev in events
)
new_extrem = {}
for room_id in events_by_room:
event_ids = self._simple_select_onecol_txn(
txn,
table="event_forward_extremities",
keyvalues={"room_id": room_id},
retcol="event_id",
)
new_extrem[room_id] = event_ids
self._simple_insert_many_txn(
txn,
table="stream_ordering_to_exterm",
values=[
{
"room_id": room_id,
"event_id": event_id,
"stream_ordering": max_stream_ord,
}
for room_id, extrem_evs in new_extrem.items()
for event_id in extrem_evs
]
)
query = (
"INSERT INTO event_backward_extremities (event_id, room_id)"
" SELECT ?, ? WHERE NOT EXISTS ("
@ -305,6 +344,48 @@ class EventFederationStore(SQLBaseStore):
self.get_latest_event_ids_in_room.invalidate, (room_id,)
)
def get_forward_extremeties_for_room(self, room_id, stream_ordering):
"""For a given room_id and stream_ordering, return the forward
extremeties of the room at that point in "time".
Throws a StoreError if we have since purged the index for
stream_orderings from that point.
"""
if stream_ordering <= self.stream_ordering_month_ago:
raise StoreError(400, "stream_ordering too old")
sql = ("""
SELECT event_id FROM stream_ordering_to_exterm
INNER JOIN (
SELECT room_id, MAX(stream_ordering) AS stream_ordering
FROM stream_ordering_to_exterm
WHERE stream_ordering < ? GROUP BY room_id
) AS rms USING (room_id, stream_ordering)
WHERE room_id = ?
""")
def get_forward_extremeties_for_room_txn(txn):
txn.execute(sql, (room_id, stream_ordering,))
rows = txn.fetchall()
return [event_id for event_id, in rows]
return self.runInteraction(
"get_forward_extremeties_for_room",
get_forward_extremeties_for_room_txn
)
def _delete_old_forward_extrem_cache(self):
def _delete_old_forward_extrem_cache_txn(txn):
txn.execute(
"DELETE FROM stream_ordering_to_exterm WHERE stream_ordering < ?",
(self.stream_ordering_month_ago,)
)
return self.runInteraction(
"_delete_old_forward_extrem_cache",
_delete_old_forward_extrem_cache_txn
)
def get_backfill_events(self, room_id, event_list, limit):
"""Get a list of Events for a given topic that occurred before (and
including) the events in event_list. Return a list of max size `limit`

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@ -0,0 +1,37 @@
/* Copyright 2016 OpenMarket Ltd
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
CREATE TABLE stream_ordering_to_exterm (
stream_ordering BIGINT NOT NULL,
room_id TEXT NOT NULL,
event_id TEXT NOT NULL
);
INSERT INTO stream_ordering_to_exterm (stream_ordering, room_id, event_id)
SELECT stream_ordering, room_id, event_id FROM event_forward_extremities
INNER JOIN (
SELECT room_id, max(stream_ordering) as stream_ordering FROM events
INNER JOIN event_forward_extremities USING (room_id, event_id)
GROUP BY room_id
) AS rms USING (room_id);
CREATE INDEX stream_ordering_to_exterm_idx on stream_ordering_to_exterm(
stream_ordering
);
CREATE INDEX stream_ordering_to_exterm_rm_idx on stream_ordering_to_exterm(
room_id, stream_ordering
);