From ad50510a06d035a674f0eeed5db5dd3060bc0b1c Mon Sep 17 00:00:00 2001 From: Nick Mills-Barrett Date: Thu, 18 May 2023 19:37:31 +0100 Subject: [PATCH] Handle missing previous read marker event. (#15464) If the previous read marker is pointing to an event that no longer exists (e.g. due to retention) then assume that the newly given read marker is newer. --- changelog.d/15464.bugfix | 1 + synapse/handlers/read_marker.py | 18 ++- .../storage/databases/main/events_worker.py | 6 - tests/rest/client/test_read_marker.py | 147 ++++++++++++++++++ 4 files changed, 162 insertions(+), 10 deletions(-) create mode 100644 changelog.d/15464.bugfix create mode 100644 tests/rest/client/test_read_marker.py diff --git a/changelog.d/15464.bugfix b/changelog.d/15464.bugfix new file mode 100644 index 000000000..3c655989b --- /dev/null +++ b/changelog.d/15464.bugfix @@ -0,0 +1 @@ +Fix a long-standing bug where setting the read marker could fail when using message retention. Contributed by Nick @ Beeper (@fizzadar). diff --git a/synapse/handlers/read_marker.py b/synapse/handlers/read_marker.py index 6d35e6188..49a497a86 100644 --- a/synapse/handlers/read_marker.py +++ b/synapse/handlers/read_marker.py @@ -16,6 +16,7 @@ import logging from typing import TYPE_CHECKING from synapse.api.constants import ReceiptTypes +from synapse.api.errors import SynapseError from synapse.util.async_helpers import Linearizer if TYPE_CHECKING: @@ -47,12 +48,21 @@ class ReadMarkerHandler: ) should_update = True + # Get event ordering, this also ensures we know about the event + event_ordering = await self.store.get_event_ordering(event_id) if existing_read_marker: - # Only update if the new marker is ahead in the stream - should_update = await self.store.is_event_after( - event_id, existing_read_marker["event_id"] - ) + try: + old_event_ordering = await self.store.get_event_ordering( + existing_read_marker["event_id"] + ) + except SynapseError: + # Old event no longer exists, assume new is ahead. This may + # happen if the old event was removed due to retention. + pass + else: + # Only update if the new marker is ahead in the stream + should_update = event_ordering > old_event_ordering if should_update: content = {"event_id": event_id} diff --git a/synapse/storage/databases/main/events_worker.py b/synapse/storage/databases/main/events_worker.py index 53aa5933d..a39bc9097 100644 --- a/synapse/storage/databases/main/events_worker.py +++ b/synapse/storage/databases/main/events_worker.py @@ -1973,12 +1973,6 @@ class EventsWorkerStore(SQLBaseStore): return rows, to_token, True - async def is_event_after(self, event_id1: str, event_id2: str) -> bool: - """Returns True if event_id1 is after event_id2 in the stream""" - to_1, so_1 = await self.get_event_ordering(event_id1) - to_2, so_2 = await self.get_event_ordering(event_id2) - return (to_1, so_1) > (to_2, so_2) - @cached(max_entries=5000) async def get_event_ordering(self, event_id: str) -> Tuple[int, int]: res = await self.db_pool.simple_select_one( diff --git a/tests/rest/client/test_read_marker.py b/tests/rest/client/test_read_marker.py new file mode 100644 index 000000000..0eedcdb47 --- /dev/null +++ b/tests/rest/client/test_read_marker.py @@ -0,0 +1,147 @@ +# Copyright 2023 Beeper +# +# 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. +from twisted.test.proto_helpers import MemoryReactor + +import synapse.rest.admin +from synapse.api.constants import EventTypes +from synapse.rest import admin +from synapse.rest.client import login, read_marker, register, room +from synapse.server import HomeServer +from synapse.util import Clock + +from tests import unittest + +ONE_HOUR_MS = 3600000 +ONE_DAY_MS = ONE_HOUR_MS * 24 + + +class ReadMarkerTestCase(unittest.HomeserverTestCase): + servlets = [ + login.register_servlets, + register.register_servlets, + read_marker.register_servlets, + room.register_servlets, + synapse.rest.admin.register_servlets, + admin.register_servlets, + ] + + def make_homeserver(self, reactor: MemoryReactor, clock: Clock) -> HomeServer: + config = self.default_config() + + # merge this default retention config with anything that was specified in + # @override_config + retention_config = { + "enabled": True, + "allowed_lifetime_min": ONE_DAY_MS, + "allowed_lifetime_max": ONE_DAY_MS * 3, + } + retention_config.update(config.get("retention", {})) + config["retention"] = retention_config + + self.hs = self.setup_test_homeserver(config=config) + + return self.hs + + def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None: + self.owner = self.register_user("owner", "pass") + self.owner_tok = self.login("owner", "pass") + self.store = self.hs.get_datastores().main + self.clock = self.hs.get_clock() + + def test_send_read_marker(self) -> None: + room_id = self.helper.create_room_as(self.owner, tok=self.owner_tok) + + def send_message() -> str: + res = self.helper.send(room_id=room_id, body="1", tok=self.owner_tok) + return res["event_id"] + + # Test setting the read marker on the room + event_id_1 = send_message() + + channel = self.make_request( + "POST", + "/rooms/!abc:beep/read_markers", + content={ + "m.fully_read": event_id_1, + }, + access_token=self.owner_tok, + ) + self.assertEqual(channel.code, 200, channel.result) + + # Test moving the read marker to a newer event + event_id_2 = send_message() + channel = self.make_request( + "POST", + "/rooms/!abc:beep/read_markers", + content={ + "m.fully_read": event_id_2, + }, + access_token=self.owner_tok, + ) + self.assertEqual(channel.code, 200, channel.result) + + def test_send_read_marker_missing_previous_event(self) -> None: + """ + Test moving a read marker from an event that previously existed but was + later removed due to retention rules. + """ + + room_id = self.helper.create_room_as(self.owner, tok=self.owner_tok) + + # Set retention rule on the room so we remove old events to test this case + self.helper.send_state( + room_id=room_id, + event_type=EventTypes.Retention, + body={"max_lifetime": ONE_DAY_MS}, + tok=self.owner_tok, + ) + + def send_message() -> str: + res = self.helper.send(room_id=room_id, body="1", tok=self.owner_tok) + return res["event_id"] + + # Test setting the read marker on the room + event_id_1 = send_message() + + channel = self.make_request( + "POST", + "/rooms/!abc:beep/read_markers", + content={ + "m.fully_read": event_id_1, + }, + access_token=self.owner_tok, + ) + + # Send a second message (retention will not remove the latest event ever) + send_message() + # And then advance so retention rules remove the first event (where the marker is) + self.reactor.advance(ONE_DAY_MS * 2 / 1000) + + event = self.get_success(self.store.get_event(event_id_1, allow_none=True)) + assert event is None + + # TODO See https://github.com/matrix-org/synapse/issues/13476 + self.store.get_event_ordering.invalidate_all() + + # Test moving the read marker to a newer event + event_id_2 = send_message() + channel = self.make_request( + "POST", + "/rooms/!abc:beep/read_markers", + content={ + "m.fully_read": event_id_2, + }, + access_token=self.owner_tok, + ) + self.assertEqual(channel.code, 200, channel.result)