This works by taking a row level lock on the `rooms` table at the start of both transactions, ensuring that they don't run at the same time. In the event persistence transaction we also check that there is an entry still in the `rooms` table.
I can't figure out how to do this in SQLite. I was just going to lock the table, but it seems that we don't support that in SQLite either, so I'm *really* confused as to how we maintain integrity in SQLite when using `lock_table`....
This change adds a check for row existence before accessing row element, this should fix issue #10669
Signed-off-by: Vasya Boytsov vasiliy.boytsov@phystech.edu
Given that backfill and get_missing_events are basically the same thing, it's somewhat crazy that we have entirely separate code paths for them. This makes backfill use the existing get_missing_events code, and then clears up all the unused code.
* Upsert redactions in case they already exists
Occasionally, in combination with retention, redactions aren't deleted
from the database whenever they are due for deletion. The server will
eventually try to backfill the deleted events and trip over the already
existing redaction events.
Switching to an UPSERT for those events allows us to recover from there
situations. The retention code still needs fixing but that is outside of
my current comfort zone on this code base.
This is related to #8707 where the error was discussed already.
Signed-off-by: Andreas Rammhold <andreas@rammhold.de>
* Also purge redactions when purging events
Previously redacints where left behind leading to backfilling issues
when the server stumbled across the already existing yet to be
backfilled redactions.
This issues has been discussed in #8707.
Signed-off-by: Andreas Rammhold <andreas@rammhold.de>
Empirically, this helped my server considerably when handling gaps in Matrix HQ. The problem was that we would repeatedly call have_seen_events for the same set of (50K or so) auth_events, each of which would take many minutes to complete, even though it's only an index scan.
Part of #9744
Removes all redundant `# -*- coding: utf-8 -*-` lines from files, as python 3 automatically reads source code as utf-8 now.
`Signed-off-by: Jonathan de Jong <jonathan@automatia.nl>`
The idea is that in future tokens will encode a mapping of instance to position. However, we don't want to include the full instance name in the string representation, so instead we'll have a mapping between instance name and an immutable integer ID in the DB that we can use instead. We'll then do the lookup when we serialize/deserialize the token (we could alternatively pass around an `Instance` type that includes both the name and ID, but that turns out to be a lot more invasive).
