Stop populating events.content

This field is no longer read from, so we should stop populating it. Once we're
happy that this doesn't break everything, and a rollback is unlikely, we can
think about dropping the column.
This commit is contained in:
Richard van der Hoff 2018-07-26 14:12:00 +01:00
parent 1b4d73fa52
commit 5c1d301fd9
2 changed files with 93 additions and 1 deletions

View File

@ -1189,7 +1189,6 @@ class EventsStore(EventsWorkerStore):
"type": event.type,
"processed": True,
"outlier": event.internal_metadata.is_outlier(),
"content": encode_json(event.content).decode("UTF-8"),
"origin_server_ts": int(event.origin_server_ts),
"received_ts": self._clock.time_msec(),
"sender": event.sender,

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@ -0,0 +1,93 @@
# -*- coding: utf-8 -*-
# Copyright 2018 New Vector 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.
"""
We want to stop populating 'event.content', so we need to make it nullable.
If this has to be rolled back, then the following should populate the missing data:
Postgres:
UPDATE events SET content=(ej.json::json)->'content' FROM event_json ej
WHERE ej.event_id = events.event_id AND
stream_ordering < (
SELECT stream_ordering FROM events WHERE content IS NOT NULL
ORDER BY stream_ordering LIMIT 1
);
UPDATE events SET content=(ej.json::json)->'content' FROM event_json ej
WHERE ej.event_id = events.event_id AND
stream_ordering > (
SELECT stream_ordering FROM events WHERE content IS NOT NULL
ORDER BY stream_ordering DESC LIMIT 1
);
SQLite:
UPDATE events SET content=(
SELECT json_extract(json,'$.content') FROM event_json ej
WHERE ej.event_id = events.event_id
)
WHERE
stream_ordering < (
SELECT stream_ordering FROM events WHERE content IS NOT NULL
ORDER BY stream_ordering LIMIT 1
)
OR stream_ordering > (
SELECT stream_ordering FROM events WHERE content IS NOT NULL
ORDER BY stream_ordering DESC LIMIT 1
);
"""
import logging
from synapse.storage.engines import PostgresEngine
logger = logging.getLogger(__name__)
def run_create(cur, database_engine, *args, **kwargs):
if isinstance(database_engine, PostgresEngine):
cur.execute("""
ALTER TABLE events ALTER COLUMN content DROP NOT NULL;
""")
return
# sqlite is an arse about this. ref: https://www.sqlite.org/lang_altertable.html
cur.execute("PRAGMA schema_version")
(oldver,) = cur.fetchone()
cur.execute("SELECT sql FROM sqlite_master WHERE tbl_name='events' AND type='table'")
(oldsql,) = cur.fetchone()
sql = oldsql.replace("content TEXT NOT NULL", "content TEXT")
if sql == oldsql:
raise Exception("Couldn't find null constraint to drop in %s" % oldsql)
logger.info("Replacing definition of 'events' with: %s", sql)
cur.execute("PRAGMA writable_schema=ON")
cur.execute(
"UPDATE sqlite_master SET sql=? WHERE tbl_name='events' AND type='table'",
(sql, ),
)
cur.execute("PRAGMA schema_version=%i" % (oldver+1,))
cur.execute("PRAGMA writable_schema=OFF")
def run_upgrade(*args, **kwargs):
pass