forked-synapse/synapse/handlers/events.py
2022-04-20 12:57:39 +01:00

187 lines
6.6 KiB
Python

# Copyright 2014-2016 OpenMarket 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
import random
from typing import TYPE_CHECKING, Iterable, List, Optional
from synapse.api.constants import EduTypes, EventTypes, Membership, PresenceState
from synapse.api.errors import AuthError, SynapseError
from synapse.events import EventBase
from synapse.events.utils import SerializeEventConfig
from synapse.handlers.presence import format_user_presence_state
from synapse.storage.databases.main.events_worker import EventRedactBehaviour
from synapse.streams.config import PaginationConfig
from synapse.types import JsonDict, UserID
from synapse.visibility import filter_events_for_client
if TYPE_CHECKING:
from synapse.server import HomeServer
logger = logging.getLogger(__name__)
class EventStreamHandler:
def __init__(self, hs: "HomeServer"):
self.store = hs.get_datastores().main
self.clock = hs.get_clock()
self.hs = hs
self.notifier = hs.get_notifier()
self.state = hs.get_state_handler()
self._server_notices_sender = hs.get_server_notices_sender()
self._event_serializer = hs.get_event_client_serializer()
async def get_stream(
self,
auth_user_id: str,
pagin_config: PaginationConfig,
timeout: int = 0,
as_client_event: bool = True,
affect_presence: bool = True,
room_id: Optional[str] = None,
is_guest: bool = False,
) -> JsonDict:
"""Fetches the events stream for a given user."""
if room_id:
blocked = await self.store.is_room_blocked(room_id)
if blocked:
raise SynapseError(403, "This room has been blocked on this server")
# send any outstanding server notices to the user.
await self._server_notices_sender.on_user_syncing(auth_user_id)
auth_user = UserID.from_string(auth_user_id)
presence_handler = self.hs.get_presence_handler()
context = await presence_handler.user_syncing(
auth_user_id,
affect_presence=affect_presence,
presence_state=PresenceState.ONLINE,
)
with context:
if timeout:
# If they've set a timeout set a minimum limit.
timeout = max(timeout, 500)
# Add some randomness to this value to try and mitigate against
# thundering herds on restart.
timeout = random.randint(int(timeout * 0.9), int(timeout * 1.1))
stream_result = await self.notifier.get_events_for(
auth_user,
pagin_config,
timeout,
is_guest=is_guest,
explicit_room_id=room_id,
)
events = stream_result.events
time_now = self.clock.time_msec()
# When the user joins a new room, or another user joins a currently
# joined room, we need to send down presence for those users.
to_add: List[JsonDict] = []
for event in events:
if not isinstance(event, EventBase):
continue
if event.type == EventTypes.Member:
if event.membership != Membership.JOIN:
continue
# Send down presence.
if event.state_key == auth_user_id:
# Send down presence for everyone in the room.
users: Iterable[str] = await self.store.get_users_in_room(
event.room_id
)
else:
users = [event.state_key]
states = await presence_handler.get_states(users)
to_add.extend(
{
"type": EduTypes.Presence,
"content": format_user_presence_state(state, time_now),
}
for state in states
)
events.extend(to_add)
chunks = self._event_serializer.serialize_events(
events,
time_now,
config=SerializeEventConfig(as_client_event=as_client_event),
)
chunk = {
"chunk": chunks,
"start": await stream_result.start_token.to_string(self.store),
"end": await stream_result.end_token.to_string(self.store),
}
return chunk
class EventHandler:
def __init__(self, hs: "HomeServer"):
self.store = hs.get_datastores().main
self.storage = hs.get_storage()
async def get_event(
self,
user: UserID,
room_id: Optional[str],
event_id: str,
show_redacted: bool = False,
) -> Optional[EventBase]:
"""Retrieve a single specified event.
Args:
user: The user requesting the event
room_id: The expected room id. We'll return None if the
event's room does not match.
event_id: The event ID to obtain.
show_redacted: Should the full content of redacted events be returned?
Returns:
An event, or None if there is no event matching this ID.
Raises:
SynapseError if there was a problem retrieving this event, or
AuthError if the user does not have the rights to inspect this
event.
"""
redact_behaviour = (
EventRedactBehaviour.AS_IS if show_redacted else EventRedactBehaviour.REDACT
)
event = await self.store.get_event(
event_id, check_room_id=room_id, redact_behaviour=redact_behaviour
)
if not event:
return None
users = await self.store.get_users_in_room(event.room_id)
is_peeking = user.to_string() not in users
filtered = await filter_events_for_client(
self.storage, user.to_string(), [event], is_peeking=is_peeking
)
if not filtered:
raise AuthError(403, "You don't have permission to access that event.")
return event