forked-synapse/synapse/handlers/read_marker.py
Nick Mills-Barrett ad50510a06
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.
2023-05-18 14:37:31 -04:00

72 lines
2.8 KiB
Python

# Copyright 2017 Vector Creations 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.
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:
from synapse.server import HomeServer
logger = logging.getLogger(__name__)
class ReadMarkerHandler:
def __init__(self, hs: "HomeServer"):
self.server_name = hs.config.server.server_name
self.store = hs.get_datastores().main
self.account_data_handler = hs.get_account_data_handler()
self.read_marker_linearizer = Linearizer(name="read_marker")
async def received_client_read_marker(
self, room_id: str, user_id: str, event_id: str
) -> None:
"""Updates the read marker for a given user in a given room if the event ID given
is ahead in the stream relative to the current read marker.
This uses a notifier to indicate that account data should be sent down /sync if
the read marker has changed.
"""
async with self.read_marker_linearizer.queue((room_id, user_id)):
existing_read_marker = await self.store.get_account_data_for_room_and_type(
user_id, room_id, ReceiptTypes.FULLY_READ
)
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:
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}
await self.account_data_handler.add_account_data_to_room(
user_id, room_id, ReceiptTypes.FULLY_READ, content
)