Censor redactions in DB after a month

This commit is contained in:
Erik Johnston 2019-08-29 17:38:51 +01:00
parent 92c1550f4a
commit a4bf72c30c
3 changed files with 175 additions and 1 deletions

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@ -23,7 +23,7 @@ from functools import wraps
from six import iteritems, text_type
from six.moves import range
from canonicaljson import json
from canonicaljson import encode_canonical_json, json
from prometheus_client import Counter, Histogram
from twisted.internet import defer
@ -33,6 +33,7 @@ from synapse.api.constants import EventTypes
from synapse.api.errors import SynapseError
from synapse.events import EventBase # noqa: F401
from synapse.events.snapshot import EventContext # noqa: F401
from synapse.events.utils import prune_event_dict
from synapse.logging.context import PreserveLoggingContext, make_deferred_yieldable
from synapse.logging.utils import log_function
from synapse.metrics import BucketCollector
@ -262,6 +263,13 @@ class EventsStore(
hs.get_clock().looping_call(read_forward_extremities, 60 * 60 * 1000)
def _censor_redactions():
return run_as_background_process(
"_censor_redactions", self._censor_redactions
)
hs.get_clock().looping_call(_censor_redactions, 10 * 60 * 1000)
@defer.inlineCallbacks
def _read_forward_extremities(self):
def fetch(txn):
@ -1548,6 +1556,84 @@ class EventsStore(
(event.event_id, event.redacts),
)
@defer.inlineCallbacks
def _censor_redactions(self):
"""Censors all redactions older than a month that haven't been censored.
By censor we mean update the event_json table with the redacted event.
Returns:
Deferred
"""
if self.stream_ordering_month_ago is None:
return
max_pos = self.stream_ordering_month_ago
# We fetch all redactions that point to an event that we have that has
# a stream ordering from over a month ago, that we haven't yet censored
# in the DB.
sql = """
SELECT er.event_id, redacts FROM redactions
INNER JOIN events AS er USING (event_id)
INNER JOIN events AS eb ON (er.room_id = eb.room_id AND redacts = eb.event_id)
WHERE NOT have_censored
AND ? <= er.stream_ordering AND er.stream_ordering <= ?
ORDER BY er.stream_ordering ASC
LIMIT ?
"""
rows = yield self._execute(
"_censor_redactions_fetch", None, sql, -max_pos, max_pos, 100
)
updates = []
for redaction_id, event_id in rows:
redaction_event = yield self.get_event(redaction_id, allow_none=True)
original_event = yield self.get_event(
event_id, allow_rejected=True, allow_none=True
)
# The SQL above ensures that we have both the redaction and
# original event, so if the `get_event` calls return None it
# means that the redaction wasn't allowed. Either way we know that
# the result won't change so we mark the fact that we've checked.
if (
redaction_event
and original_event
and original_event.internal_metadata.is_redacted()
):
# Redaction was allowed
pruned_json = encode_canonical_json(
prune_event_dict(original_event.get_dict())
)
else:
# Redaction wasn't allowed
pruned_json = None
updates.append((redaction_id, event_id, pruned_json))
def _update_censor_txn(txn):
for redaction_id, event_id, pruned_json in updates:
if pruned_json:
self._simple_update_one_txn(
txn,
table="event_json",
keyvalues={"event_id": event_id},
updatevalues={"json": pruned_json},
)
self._simple_update_one_txn(
txn,
table="redactions",
keyvalues={"event_id": redaction_id},
updatevalues={"have_censored": True},
)
yield self.runInteraction("_update_censor_txn", _update_censor_txn)
@defer.inlineCallbacks
def count_daily_messages(self):
"""

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@ -0,0 +1,17 @@
/* Copyright 2019 The Matrix.org Foundation C.I.C.
*
* 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.
*/
ALTER TABLE redactions ADD COLUMN have_censored BOOL NOT NULL DEFAULT false;
CREATE INDEX redactions_have_censored ON redactions(event_id) WHERE not have_censored;

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@ -17,6 +17,8 @@
from mock import Mock
from canonicaljson import json
from twisted.internet import defer
from synapse.api.constants import EventTypes, Membership
@ -286,3 +288,72 @@ class RedactionTestCase(unittest.HomeserverTestCase):
self.assertEqual(
fetched.unsigned["redacted_because"].event_id, redaction_event_id2
)
def test_redact_censor(self):
"""Test that a redacted event gets censored in the DB after a month
"""
self.get_success(
self.inject_room_member(self.room1, self.u_alice, Membership.JOIN)
)
msg_event = self.get_success(self.inject_message(self.room1, self.u_alice, "t"))
# Check event has not been redacted:
event = self.get_success(self.store.get_event(msg_event.event_id))
self.assertObjectHasAttributes(
{
"type": EventTypes.Message,
"user_id": self.u_alice.to_string(),
"content": {"body": "t", "msgtype": "message"},
},
event,
)
self.assertFalse("redacted_because" in event.unsigned)
# Redact event
reason = "Because I said so"
self.get_success(
self.inject_redaction(self.room1, msg_event.event_id, self.u_alice, reason)
)
event = self.get_success(self.store.get_event(msg_event.event_id))
self.assertTrue("redacted_because" in event.unsigned)
self.assertObjectHasAttributes(
{
"type": EventTypes.Message,
"user_id": self.u_alice.to_string(),
"content": {},
},
event,
)
event_json = self.get_success(
self.store._simple_select_one_onecol(
table="event_json",
keyvalues={"event_id": msg_event.event_id},
retcol="json",
)
)
self.assert_dict(
{"content": {"body": "t", "msgtype": "message"}}, json.loads(event_json)
)
# Advance by 30 days
self.reactor.advance(60 * 60 * 24 * 31)
self.reactor.advance(60 * 60 * 2)
event_json = self.get_success(
self.store._simple_select_one_onecol(
table="event_json",
keyvalues={"event_id": msg_event.event_id},
retcol="json",
)
)
self.assert_dict({"content": {}}, json.loads(event_json))