forked-synapse/synapse/storage/schema/main/delta/78/03event_extremities_constraints.py
Erik Johnston 23740eaa3d
Correctly mention previous copyright (#16820)
During the migration the automated script to update the copyright
headers accidentally got rid of some of the existing copyright lines.
Reinstate them.
2024-01-23 11:26:48 +00:00

65 lines
2.5 KiB
Python

#
# This file is licensed under the Affero General Public License (AGPL) version 3.
#
# Copyright 2023 The Matrix.org Foundation C.I.C.
# Copyright (C) 2023 New Vector, Ltd
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# See the GNU Affero General Public License for more details:
# <https://www.gnu.org/licenses/agpl-3.0.html>.
#
# Originally licensed under the Apache License, Version 2.0:
# <http://www.apache.org/licenses/LICENSE-2.0>.
#
# [This file includes modifications made by New Vector Limited]
#
#
"""
This migration adds foreign key constraint to `event_forward_extremities` table.
"""
from synapse.storage.background_updates import (
ForeignKeyConstraint,
run_validate_constraint_and_delete_rows_schema_delta,
)
from synapse.storage.database import LoggingTransaction
from synapse.storage.engines import BaseDatabaseEngine
FORWARD_EXTREMITIES_TABLE_SCHEMA = """
CREATE TABLE event_forward_extremities2(
event_id TEXT NOT NULL,
room_id TEXT NOT NULL,
UNIQUE (event_id, room_id),
CONSTRAINT event_forward_extremities_event_id FOREIGN KEY (event_id) REFERENCES events (event_id) DEFERRABLE INITIALLY DEFERRED
)
"""
def run_create(cur: LoggingTransaction, database_engine: BaseDatabaseEngine) -> None:
# We mark this as a deferred constraint, as the previous version of Synapse
# inserted the event into the forward extremities *before* the events table.
# By marking as deferred we ensure that downgrading to the previous version
# will continue to work.
run_validate_constraint_and_delete_rows_schema_delta(
cur,
ordering=7803,
update_name="event_forward_extremities_event_id_foreign_key_constraint_update",
table="event_forward_extremities",
constraint_name="event_forward_extremities_event_id",
constraint=ForeignKeyConstraint(
"events", [("event_id", "event_id")], deferred=True
),
sqlite_table_name="event_forward_extremities2",
sqlite_table_schema=FORWARD_EXTREMITIES_TABLE_SCHEMA,
)
# We can't add a similar constraint to `event_backward_extremities` as the
# events in there don't exist in the `events` table and `event_edges`
# doesn't have a unique constraint on `prev_event_id` (so we can't make a
# foreign key point to it).