diff options
Diffstat (limited to 'synapse/handlers/sliding_sync.py')
| -rw-r--r-- | synapse/handlers/sliding_sync.py | 642 |
1 files changed, 490 insertions, 152 deletions
diff --git a/synapse/handlers/sliding_sync.py b/synapse/handlers/sliding_sync.py index 847a638bba..8622ef8472 100644 --- a/synapse/handlers/sliding_sync.py +++ b/synapse/handlers/sliding_sync.py @@ -18,22 +18,28 @@ # # import logging -from typing import TYPE_CHECKING, Dict, List, Optional, Tuple +from typing import TYPE_CHECKING, Any, Dict, List, Optional, Set, Tuple +import attr from immutabledict import immutabledict -from synapse.api.constants import AccountDataTypes, EventTypes, Membership +from synapse.api.constants import AccountDataTypes, Direction, EventTypes, Membership from synapse.events import EventBase -from synapse.storage.roommember import RoomsForUser +from synapse.events.utils import strip_event +from synapse.handlers.relations import BundledAggregations +from synapse.storage.databases.main.stream import CurrentStateDeltaMembership from synapse.types import ( + JsonDict, PersistedEventPosition, Requester, RoomStreamToken, + StreamKeyType, StreamToken, UserID, ) from synapse.types.handlers import OperationType, SlidingSyncConfig, SlidingSyncResult from synapse.types.state import StateFilter +from synapse.visibility import filter_events_for_client if TYPE_CHECKING: from synapse.server import HomeServer @@ -41,28 +47,9 @@ if TYPE_CHECKING: logger = logging.getLogger(__name__) -def convert_event_to_rooms_for_user(event: EventBase) -> RoomsForUser: - """ - Quick helper to convert an event to a `RoomsForUser` object. - """ - # These fields should be present for all persisted events - assert event.internal_metadata.stream_ordering is not None - assert event.internal_metadata.instance_name is not None - - return RoomsForUser( - room_id=event.room_id, - sender=event.sender, - membership=event.membership, - event_id=event.event_id, - event_pos=PersistedEventPosition( - event.internal_metadata.instance_name, - event.internal_metadata.stream_ordering, - ), - room_version_id=event.room_version.identifier, - ) - - -def filter_membership_for_sync(*, membership: str, user_id: str, sender: str) -> bool: +def filter_membership_for_sync( + *, membership: str, user_id: str, sender: Optional[str] +) -> bool: """ Returns True if the membership event should be included in the sync response, otherwise False. @@ -79,7 +66,54 @@ def filter_membership_for_sync(*, membership: str, user_id: str, sender: str) -> # # This logic includes kicks (leave events where the sender is not the same user) and # can be read as "anything that isn't a leave or a leave with a different sender". - return membership != Membership.LEAVE or sender != user_id + # + # When `sender=None` and `membership=Membership.LEAVE`, it means that a state reset + # happened that removed the user from the room, or the user was the last person + # locally to leave the room which caused the server to leave the room. In both + # cases, we can just remove the rooms since they are no longer relevant to the user. + # They could still be added back later if they are `newly_left`. + return membership != Membership.LEAVE or sender not in (user_id, None) + + +# We can't freeze this class because we want to update it in place with the +# de-duplicated data. +@attr.s(slots=True, auto_attribs=True) +class RoomSyncConfig: + """ + Holds the config for what data we should fetch for a room in the sync response. + + Attributes: + timeline_limit: The maximum number of events to return in the timeline. + required_state: The set of state events requested for the room. The + values are close to `StateKey` but actually use a syntax where you can + provide `*` wildcard and `$LAZY` for lazy room members as the `state_key` part + of the tuple (type, state_key). + """ + + timeline_limit: int + required_state: Set[Tuple[str, str]] + + +@attr.s(slots=True, frozen=True, auto_attribs=True) +class _RoomMembershipForUser: + """ + Attributes: + event_id: The event ID of the membership event + event_pos: The stream position of the membership event + membership: The membership state of the user in the room + sender: The person who sent the membership event + newly_joined: Whether the user newly joined the room during the given token + range + """ + + event_id: Optional[str] + event_pos: PersistedEventPosition + membership: str + sender: Optional[str] + newly_joined: bool + + def copy_and_replace(self, **kwds: Any) -> "_RoomMembershipForUser": + return attr.evolve(self, **kwds) class SlidingSyncHandler: @@ -90,6 +124,7 @@ class SlidingSyncHandler: self.auth_blocking = hs.get_auth_blocking() self.notifier = hs.get_notifier() self.event_sources = hs.get_event_sources() + self.relations_handler = hs.get_relations_handler() self.rooms_to_exclude_globally = hs.config.server.rooms_to_exclude_from_sync async def wait_for_sync_for_user( @@ -201,6 +236,7 @@ class SlidingSyncHandler: # Assemble sliding window lists lists: Dict[str, SlidingSyncResult.SlidingWindowList] = {} + relevant_room_map: Dict[str, RoomSyncConfig] = {} if sync_config.lists: # Get all of the room IDs that the user should be able to see in the sync # response @@ -225,29 +261,67 @@ class SlidingSyncHandler: ops: List[SlidingSyncResult.SlidingWindowList.Operation] = [] if list_config.ranges: for range in list_config.ranges: + sliced_room_ids = [ + room_id + # Both sides of range are inclusive + for room_id, _ in sorted_room_info[range[0] : range[1] + 1] + ] + ops.append( SlidingSyncResult.SlidingWindowList.Operation( op=OperationType.SYNC, range=range, - room_ids=[ - room_id - for room_id, _ in sorted_room_info[ - range[0] : range[1] - ] - ], + room_ids=sliced_room_ids, ) ) + # Take the superset of the `RoomSyncConfig` for each room + for room_id in sliced_room_ids: + if relevant_room_map.get(room_id) is not None: + # Take the highest timeline limit + if ( + relevant_room_map[room_id].timeline_limit + < list_config.timeline_limit + ): + relevant_room_map[room_id].timeline_limit = ( + list_config.timeline_limit + ) + + # Union the required state + relevant_room_map[room_id].required_state.update( + list_config.required_state + ) + else: + relevant_room_map[room_id] = RoomSyncConfig( + timeline_limit=list_config.timeline_limit, + required_state=set(list_config.required_state), + ) + lists[list_key] = SlidingSyncResult.SlidingWindowList( count=len(sorted_room_info), ops=ops, ) + # TODO: if (sync_config.room_subscriptions): + + # Fetch room data + rooms: Dict[str, SlidingSyncResult.RoomResult] = {} + for room_id, room_sync_config in relevant_room_map.items(): + room_sync_result = await self.get_room_sync_data( + user=sync_config.user, + room_id=room_id, + room_sync_config=room_sync_config, + rooms_membership_for_user_at_to_token=sync_room_map[room_id], + from_token=from_token, + to_token=to_token, + ) + + rooms[room_id] = room_sync_result + return SlidingSyncResult( next_pos=to_token, lists=lists, - # TODO: Gather room data for rooms in lists and `sync_config.room_subscriptions` - rooms={}, + rooms=rooms, extensions={}, ) @@ -256,7 +330,7 @@ class SlidingSyncHandler: user: UserID, to_token: StreamToken, from_token: Optional[StreamToken] = None, - ) -> Dict[str, RoomsForUser]: + ) -> Dict[str, _RoomMembershipForUser]: """ Fetch room IDs that should be listed for this user in the sync response (the full room list that will be filtered, sorted, and sliced). @@ -305,13 +379,17 @@ class SlidingSyncHandler: # Our working list of rooms that can show up in the sync response sync_room_id_set = { - room_for_user.room_id: room_for_user - for room_for_user in room_for_user_list - if filter_membership_for_sync( + # Note: The `room_for_user` we're assigning here will need to be fixed up + # (below) because they are potentially from the current snapshot time + # instead from the time of the `to_token`. + room_for_user.room_id: _RoomMembershipForUser( + event_id=room_for_user.event_id, + event_pos=room_for_user.event_pos, membership=room_for_user.membership, - user_id=user_id, sender=room_for_user.sender, + newly_joined=False, ) + for room_for_user in room_for_user_list } # Get the `RoomStreamToken` that represents the spot we queried up to when we got @@ -346,14 +424,9 @@ class SlidingSyncHandler: # # - 1a) Remove rooms that the user joined after the `to_token` # - 1b) Add back rooms that the user left after the `to_token` + # - 1c) Update room membership events to the point in time of the `to_token` # - 2) Add back newly_left rooms (> `from_token` and <= `to_token`) - # - # Below, we're doing two separate lookups for membership changes. We could - # request everything for both fixups in one range, [`from_token.room_key`, - # `membership_snapshot_token`), but we want to avoid raw `stream_ordering` - # comparison without `instance_name` (which is flawed). We could refactor - # `event.internal_metadata` to include `instance_name` but it might turn out a - # little difficult and a bigger, broader Synapse change than we want to make. + # - 3) Figure out which rooms are `newly_joined` # 1) ----------------------------------------------------- @@ -363,159 +436,198 @@ class SlidingSyncHandler: # If our `to_token` is already the same or ahead of the latest room membership # for the user, we don't need to do any "2)" fix-ups and can just straight-up # use the room list from the snapshot as a base (nothing has changed) - membership_change_events_after_to_token = [] + current_state_delta_membership_changes_after_to_token = [] if not membership_snapshot_token.is_before_or_eq(to_token.room_key): - membership_change_events_after_to_token = ( - await self.store.get_membership_changes_for_user( + current_state_delta_membership_changes_after_to_token = ( + await self.store.get_current_state_delta_membership_changes_for_user( user_id, from_key=to_token.room_key, to_key=membership_snapshot_token, - excluded_rooms=self.rooms_to_exclude_globally, + excluded_room_ids=self.rooms_to_exclude_globally, ) ) - # 1) Assemble a list of the last membership events in some given ranges. Someone - # could have left and joined multiple times during the given range but we only - # care about end-result so we grab the last one. - last_membership_change_by_room_id_after_to_token: Dict[str, EventBase] = {} - # We also need the first membership event after the `to_token` so we can step - # backward to the previous membership that would apply to the from/to range. - first_membership_change_by_room_id_after_to_token: Dict[str, EventBase] = {} - for event in membership_change_events_after_to_token: - last_membership_change_by_room_id_after_to_token[event.room_id] = event + # 1) Assemble a list of the first membership event after the `to_token` so we can + # step backward to the previous membership that would apply to the from/to + # range. + first_membership_change_by_room_id_after_to_token: Dict[ + str, CurrentStateDeltaMembership + ] = {} + for membership_change in current_state_delta_membership_changes_after_to_token: # Only set if we haven't already set it first_membership_change_by_room_id_after_to_token.setdefault( - event.room_id, event + membership_change.room_id, membership_change ) # 1) Fixup + # + # Since we fetched a snapshot of the users room list at some point in time after + # the from/to tokens, we need to revert/rewind some membership changes to match + # the point in time of the `to_token`. for ( - last_membership_change_after_to_token - ) in last_membership_change_by_room_id_after_to_token.values(): - room_id = last_membership_change_after_to_token.room_id - - # We want to find the first membership change after the `to_token` then step - # backward to know the membership in the from/to range. - first_membership_change_after_to_token = ( - first_membership_change_by_room_id_after_to_token.get(room_id) - ) - assert first_membership_change_after_to_token is not None, ( - "If there was a `last_membership_change_after_to_token` that we're iterating over, " - + "then there should be corresponding a first change. For example, even if there " - + "is only one event after the `to_token`, the first and last event will be same event. " - + "This is probably a mistake in assembling the `last_membership_change_by_room_id_after_to_token`" - + "/`first_membership_change_by_room_id_after_to_token` dicts above." - ) - # TODO: Instead of reading from `unsigned`, refactor this to use the - # `current_state_delta_stream` table in the future. Probably a new - # `get_membership_changes_for_user()` function that uses - # `current_state_delta_stream` with a join to `room_memberships`. This would - # help in state reset scenarios since `prev_content` is looking at the - # current branch vs the current room state. This is all just data given to - # the client so no real harm to data integrity, but we'd like to be nice to - # the client. Since the `current_state_delta_stream` table is new, it - # doesn't have all events in it. Since this is Sliding Sync, if we ever need - # to, we can signal the client to throw all of their state away by sending - # "operation: RESET". - prev_content = first_membership_change_after_to_token.unsigned.get( - "prev_content", {} - ) - prev_membership = prev_content.get("membership", None) - prev_sender = first_membership_change_after_to_token.unsigned.get( - "prev_sender", None - ) - - # Check if the previous membership (membership that applies to the from/to - # range) should be included in our `sync_room_id_set` - should_prev_membership_be_included = ( - prev_membership is not None - and prev_sender is not None - and filter_membership_for_sync( - membership=prev_membership, - user_id=user_id, - sender=prev_sender, - ) - ) - - # Check if the last membership (membership that applies to our snapshot) was - # already included in our `sync_room_id_set` - was_last_membership_already_included = filter_membership_for_sync( - membership=last_membership_change_after_to_token.membership, + room_id, + first_membership_change_after_to_token, + ) in first_membership_change_by_room_id_after_to_token.items(): + # 1a) Remove rooms that the user joined after the `to_token` + if first_membership_change_after_to_token.prev_event_id is None: + sync_room_id_set.pop(room_id, None) + # 1b) 1c) From the first membership event after the `to_token`, step backward to the + # previous membership that would apply to the from/to range. + else: + # We don't expect these fields to be `None` if we have a `prev_event_id` + # but we're being defensive since it's possible that the prev event was + # culled from the database. + if ( + first_membership_change_after_to_token.prev_event_pos is not None + and first_membership_change_after_to_token.prev_membership + is not None + ): + sync_room_id_set[room_id] = _RoomMembershipForUser( + event_id=first_membership_change_after_to_token.prev_event_id, + event_pos=first_membership_change_after_to_token.prev_event_pos, + membership=first_membership_change_after_to_token.prev_membership, + sender=first_membership_change_after_to_token.prev_sender, + newly_joined=False, + ) + else: + # If we can't find the previous membership event, we shouldn't + # include the room in the sync response since we can't determine the + # exact membership state and shouldn't rely on the current snapshot. + sync_room_id_set.pop(room_id, None) + + # Filter the rooms that that we have updated room membership events to the point + # in time of the `to_token` (from the "1)" fixups) + filtered_sync_room_id_set = { + room_id: room_membership_for_user + for room_id, room_membership_for_user in sync_room_id_set.items() + if filter_membership_for_sync( + membership=room_membership_for_user.membership, user_id=user_id, - sender=last_membership_change_after_to_token.sender, + sender=room_membership_for_user.sender, ) - - # 1a) Add back rooms that the user left after the `to_token` - # - # For example, if the last membership event after the `to_token` is a leave - # event, then the room was excluded from `sync_room_id_set` when we first - # crafted it above. We should add these rooms back as long as the user also - # was part of the room before the `to_token`. - if ( - not was_last_membership_already_included - and should_prev_membership_be_included - ): - sync_room_id_set[room_id] = convert_event_to_rooms_for_user( - last_membership_change_after_to_token - ) - # 1b) Remove rooms that the user joined (hasn't left) after the `to_token` - # - # For example, if the last membership event after the `to_token` is a "join" - # event, then the room was included `sync_room_id_set` when we first crafted - # it above. We should remove these rooms as long as the user also wasn't - # part of the room before the `to_token`. - elif ( - was_last_membership_already_included - and not should_prev_membership_be_included - ): - del sync_room_id_set[room_id] + } # 2) ----------------------------------------------------- # We fix-up newly_left rooms after the first fixup because it may have removed - # some left rooms that we can figure out our newly_left in the following code + # some left rooms that we can figure out are newly_left in the following code # 2) Fetch membership changes that fall in the range from `from_token` up to `to_token` - membership_change_events_in_from_to_range = [] + current_state_delta_membership_changes_in_from_to_range = [] if from_token: - membership_change_events_in_from_to_range = ( - await self.store.get_membership_changes_for_user( + current_state_delta_membership_changes_in_from_to_range = ( + await self.store.get_current_state_delta_membership_changes_for_user( user_id, from_key=from_token.room_key, to_key=to_token.room_key, - excluded_rooms=self.rooms_to_exclude_globally, + excluded_room_ids=self.rooms_to_exclude_globally, ) ) # 2) Assemble a list of the last membership events in some given ranges. Someone # could have left and joined multiple times during the given range but we only # care about end-result so we grab the last one. - last_membership_change_by_room_id_in_from_to_range: Dict[str, EventBase] = {} - for event in membership_change_events_in_from_to_range: - last_membership_change_by_room_id_in_from_to_range[event.room_id] = event + last_membership_change_by_room_id_in_from_to_range: Dict[ + str, CurrentStateDeltaMembership + ] = {} + # We also want to assemble a list of the first membership events during the token + # range so we can step backward to the previous membership that would apply to + # before the token range to see if we have `newly_joined` the room. + first_membership_change_by_room_id_in_from_to_range: Dict[ + str, CurrentStateDeltaMembership + ] = {} + # Keep track if the room has a non-join event in the token range so we can later + # tell if it was a `newly_joined` room. If the last membership event in the + # token range is a join and there is also some non-join in the range, we know + # they `newly_joined`. + has_non_join_event_by_room_id_in_from_to_range: Dict[str, bool] = {} + for ( + membership_change + ) in current_state_delta_membership_changes_in_from_to_range: + room_id = membership_change.room_id + + last_membership_change_by_room_id_in_from_to_range[room_id] = ( + membership_change + ) + # Only set if we haven't already set it + first_membership_change_by_room_id_in_from_to_range.setdefault( + room_id, membership_change + ) + + if membership_change.membership != Membership.JOIN: + has_non_join_event_by_room_id_in_from_to_range[room_id] = True # 2) Fixup + # + # 3) We also want to assemble a list of possibly newly joined rooms. Someone + # could have left and joined multiple times during the given range but we only + # care about whether they are joined at the end of the token range so we are + # working with the last membership even in the token range. + possibly_newly_joined_room_ids = set() for ( last_membership_change_in_from_to_range ) in last_membership_change_by_room_id_in_from_to_range.values(): room_id = last_membership_change_in_from_to_range.room_id + # 3) + if last_membership_change_in_from_to_range.membership == Membership.JOIN: + possibly_newly_joined_room_ids.add(room_id) + # 2) Add back newly_left rooms (> `from_token` and <= `to_token`). We # include newly_left rooms because the last event that the user should see # is their own leave event if last_membership_change_in_from_to_range.membership == Membership.LEAVE: - sync_room_id_set[room_id] = convert_event_to_rooms_for_user( - last_membership_change_in_from_to_range + filtered_sync_room_id_set[room_id] = _RoomMembershipForUser( + event_id=last_membership_change_in_from_to_range.event_id, + event_pos=last_membership_change_in_from_to_range.event_pos, + membership=last_membership_change_in_from_to_range.membership, + sender=last_membership_change_in_from_to_range.sender, + newly_joined=False, ) - return sync_room_id_set + # 3) Figure out `newly_joined` + for room_id in possibly_newly_joined_room_ids: + has_non_join_in_from_to_range = ( + has_non_join_event_by_room_id_in_from_to_range.get(room_id, False) + ) + # If the last membership event in the token range is a join and there is + # also some non-join in the range, we know they `newly_joined`. + if has_non_join_in_from_to_range: + # We found a `newly_joined` room (we left and joined within the token range) + filtered_sync_room_id_set[room_id] = filtered_sync_room_id_set[ + room_id + ].copy_and_replace(newly_joined=True) + else: + prev_event_id = first_membership_change_by_room_id_in_from_to_range[ + room_id + ].prev_event_id + prev_membership = first_membership_change_by_room_id_in_from_to_range[ + room_id + ].prev_membership + + if prev_event_id is None: + # We found a `newly_joined` room (we are joining the room for the + # first time within the token range) + filtered_sync_room_id_set[room_id] = filtered_sync_room_id_set[ + room_id + ].copy_and_replace(newly_joined=True) + # Last resort, we need to step back to the previous membership event + # just before the token range to see if we're joined then or not. + elif prev_membership != Membership.JOIN: + # We found a `newly_joined` room (we left before the token range + # and joined within the token range) + filtered_sync_room_id_set[room_id] = filtered_sync_room_id_set[ + room_id + ].copy_and_replace(newly_joined=True) + + return filtered_sync_room_id_set async def filter_rooms( self, user: UserID, - sync_room_map: Dict[str, RoomsForUser], + sync_room_map: Dict[str, _RoomMembershipForUser], filters: SlidingSyncConfig.SlidingSyncList.Filters, to_token: StreamToken, - ) -> Dict[str, RoomsForUser]: + ) -> Dict[str, _RoomMembershipForUser]: """ Filter rooms based on the sync request. @@ -629,9 +741,9 @@ class SlidingSyncHandler: async def sort_rooms( self, - sync_room_map: Dict[str, RoomsForUser], + sync_room_map: Dict[str, _RoomMembershipForUser], to_token: StreamToken, - ) -> List[Tuple[str, RoomsForUser]]: + ) -> List[Tuple[str, _RoomMembershipForUser]]: """ Sort by `stream_ordering` of the last event that the user should see in the room. `stream_ordering` is unique so we get a stable sort. @@ -678,3 +790,229 @@ class SlidingSyncHandler: # We want descending order reverse=True, ) + + async def get_room_sync_data( + self, + user: UserID, + room_id: str, + room_sync_config: RoomSyncConfig, + rooms_membership_for_user_at_to_token: _RoomMembershipForUser, + from_token: Optional[StreamToken], + to_token: StreamToken, + ) -> SlidingSyncResult.RoomResult: + """ + Fetch room data for the sync response. + + We fetch data according to the token range (> `from_token` and <= `to_token`). + + Args: + user: User to fetch data for + room_id: The room ID to fetch data for + room_sync_config: Config for what data we should fetch for a room in the + sync response. + rooms_membership_for_user_at_to_token: Membership information for the user + in the room at the time of `to_token`. + from_token: The point in the stream to sync from. + to_token: The point in the stream to sync up to. + """ + + # Assemble the list of timeline events + # + # It would be nice to make the `rooms` response more uniform regardless of + # membership. Currently, we have to make all of these optional because + # `invite`/`knock` rooms only have `stripped_state`. See + # https://github.com/matrix-org/matrix-spec-proposals/pull/3575#discussion_r1653045932 + timeline_events: Optional[List[EventBase]] = None + bundled_aggregations: Optional[Dict[str, BundledAggregations]] = None + limited: Optional[bool] = None + prev_batch_token: Optional[StreamToken] = None + num_live: Optional[int] = None + if ( + room_sync_config.timeline_limit > 0 + # No timeline for invite/knock rooms (just `stripped_state`) + and rooms_membership_for_user_at_to_token.membership + not in (Membership.INVITE, Membership.KNOCK) + ): + limited = False + # We want to start off using the `to_token` (vs `from_token`) because we look + # backwards from the `to_token` up to the `timeline_limit` and we might not + # reach the `from_token` before we hit the limit. We will update the room stream + # position once we've fetched the events to point to the earliest event fetched. + prev_batch_token = to_token + + # We're going to paginate backwards from the `to_token` + from_bound = to_token.room_key + # People shouldn't see past their leave/ban event + if rooms_membership_for_user_at_to_token.membership in ( + Membership.LEAVE, + Membership.BAN, + ): + from_bound = ( + rooms_membership_for_user_at_to_token.event_pos.to_room_stream_token() + ) + + # Determine whether we should limit the timeline to the token range. + # + # We should return historical messages (before token range) in the + # following cases because we want clients to be able to show a basic + # screen of information: + # - Initial sync (because no `from_token` to limit us anyway) + # - When users `newly_joined` + # - TODO: For an incremental sync where we haven't sent it down this + # connection before + to_bound = ( + from_token.room_key + if from_token is not None + and not rooms_membership_for_user_at_to_token.newly_joined + else None + ) + + timeline_events, new_room_key = await self.store.paginate_room_events( + room_id=room_id, + from_key=from_bound, + to_key=to_bound, + direction=Direction.BACKWARDS, + # We add one so we can determine if there are enough events to saturate + # the limit or not (see `limited`) + limit=room_sync_config.timeline_limit + 1, + event_filter=None, + ) + + # We want to return the events in ascending order (the last event is the + # most recent). + timeline_events.reverse() + + # Determine our `limited` status based on the timeline. We do this before + # filtering the events so we can accurately determine if there is more to + # paginate even if we filter out some/all events. + if len(timeline_events) > room_sync_config.timeline_limit: + limited = True + # Get rid of that extra "+ 1" event because we only used it to determine + # if we hit the limit or not + timeline_events = timeline_events[-room_sync_config.timeline_limit :] + assert timeline_events[0].internal_metadata.stream_ordering + new_room_key = RoomStreamToken( + stream=timeline_events[0].internal_metadata.stream_ordering - 1 + ) + + # Make sure we don't expose any events that the client shouldn't see + timeline_events = await filter_events_for_client( + self.storage_controllers, + user.to_string(), + timeline_events, + is_peeking=rooms_membership_for_user_at_to_token.membership + != Membership.JOIN, + filter_send_to_client=True, + ) + # TODO: Filter out `EventTypes.CallInvite` in public rooms, + # see https://github.com/element-hq/synapse/issues/17359 + + # TODO: Handle timeline gaps (`get_timeline_gaps()`) + + # Determine how many "live" events we have (events within the given token range). + # + # This is mostly useful to determine whether a given @mention event should + # make a noise or not. Clients cannot rely solely on the absence of + # `initial: true` to determine live events because if a room not in the + # sliding window bumps into the window because of an @mention it will have + # `initial: true` yet contain a single live event (with potentially other + # old events in the timeline) + num_live = 0 + if from_token is not None: + for timeline_event in reversed(timeline_events): + # This fields should be present for all persisted events + assert timeline_event.internal_metadata.stream_ordering is not None + assert timeline_event.internal_metadata.instance_name is not None + + persisted_position = PersistedEventPosition( + instance_name=timeline_event.internal_metadata.instance_name, + stream=timeline_event.internal_metadata.stream_ordering, + ) + if persisted_position.persisted_after(from_token.room_key): + num_live += 1 + else: + # Since we're iterating over the timeline events in + # reverse-chronological order, we can break once we hit an event + # that's not live. In the future, we could potentially optimize + # this more with a binary search (bisect). + break + + # If the timeline is `limited=True`, the client does not have all events + # necessary to calculate aggregations themselves. + if limited: + bundled_aggregations = ( + await self.relations_handler.get_bundled_aggregations( + timeline_events, user.to_string() + ) + ) + + # Update the `prev_batch_token` to point to the position that allows us to + # keep paginating backwards from the oldest event we return in the timeline. + prev_batch_token = prev_batch_token.copy_and_replace( + StreamKeyType.ROOM, new_room_key + ) + + # Figure out any stripped state events for invite/knocks. This allows the + # potential joiner to identify the room. + stripped_state: List[JsonDict] = [] + if rooms_membership_for_user_at_to_token.membership in ( + Membership.INVITE, + Membership.KNOCK, + ): + # This should never happen. If someone is invited/knocked on room, then + # there should be an event for it. + assert rooms_membership_for_user_at_to_token.event_id is not None + + invite_or_knock_event = await self.store.get_event( + rooms_membership_for_user_at_to_token.event_id + ) + + stripped_state = [] + if invite_or_knock_event.membership == Membership.INVITE: + stripped_state.extend( + invite_or_knock_event.unsigned.get("invite_room_state", []) + ) + elif invite_or_knock_event.membership == Membership.KNOCK: + stripped_state.extend( + invite_or_knock_event.unsigned.get("knock_room_state", []) + ) + + stripped_state.append(strip_event(invite_or_knock_event)) + + # TODO: Handle state resets. For example, if we see + # `rooms_membership_for_user_at_to_token.membership = Membership.LEAVE` but + # `required_state` doesn't include it, we should indicate to the client that a + # state reset happened. Perhaps we should indicate this by setting `initial: + # True` and empty `required_state`. + + return SlidingSyncResult.RoomResult( + # TODO: Dummy value + name=None, + # TODO: Dummy value + avatar=None, + # TODO: Dummy value + heroes=None, + # TODO: Since we can't determine whether we've already sent a room down this + # Sliding Sync connection before (we plan to add this optimization in the + # future), we're always returning the requested room state instead of + # updates. + initial=True, + # TODO: Dummy value + required_state=[], + timeline_events=timeline_events, + bundled_aggregations=bundled_aggregations, + # TODO: Dummy value + is_dm=False, + stripped_state=stripped_state, + prev_batch=prev_batch_token, + limited=limited, + # TODO: Dummy values + joined_count=0, + invited_count=0, + # TODO: These are just dummy values. We could potentially just remove these + # since notifications can only really be done correctly on the client anyway + # (encrypted rooms). + notification_count=0, + highlight_count=0, + num_live=num_live, + ) |