Merge b886ca4a89 into 2c36a679ae

MSC4115 has now completed FCP, so we can enable it by default and switch
to the stable identifier.

changelog.d/17276.feature

@@ -0,0 +1 @@
+Filter for public and empty rooms added to Admin-API [List Room API](https://element-hq.github.io/synapse/latest/admin_api/rooms.html#list-room-api).

changelog.d/17277.feature

@@ -0,0 +1 @@
+Add `is_dm` filtering to experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint.

changelog.d/17282.feature

@@ -0,0 +1 @@
+Include user membership in events served to clients, per MSC4115.

changelog.d/17295.bugfix

@@ -0,0 +1 @@
+Fix edge case in `/sync` returning the wrong the state when using sharded event persisters.

changelog.d/17300.misc

@@ -0,0 +1 @@
+Expose the worker instance that persisted the event on `event.internal_metadata.instance_name`.

changelog.d/17301.bugfix

@@ -0,0 +1 @@
+Add initial implementation of an experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint.

docker/complement/conf/workers-shared-extra.yaml.j2

@@ -105,8 +105,6 @@ experimental_features:
   # Expose a room summary for public rooms
   msc3266_enabled: true
 
-  msc4115_membership_on_events: true
-
 server_notices:
   system_mxid_localpart: _server
   system_mxid_display_name: "Server Alert"

docs/admin_api/rooms.md

@@ -36,6 +36,10 @@ The following query parameters are available:
   - the room's name,
   - the local part of the room's canonical alias, or
   - the complete (local and server part) room's id (case sensitive).
+* `public_rooms` - Optional flag to filter public rooms. If `true`, only public rooms are queried. If `false`, public rooms are excluded from
+  the query. When the flag is absent (the default), **both** public and non-public rooms are included in the search results.
+* `empty_rooms` - Optional flag to filter empty rooms. A room is empty if joined_members is zero. If `true`, only empty rooms are queried. If `false`, empty rooms are excluded from
+  the query. When the flag is absent (the default), **both** empty and non-empty rooms are included in the search results.
 
   Defaults to no filtering.
 

rust/src/events/internal_metadata.rs

@@ -204,6 +204,8 @@ pub struct EventInternalMetadata {
     /// The stream ordering of this event. None, until it has been persisted.
     #[pyo3(get, set)]
     stream_ordering: Option<NonZeroI64>,
+    #[pyo3(get, set)]
+    instance_name: Option<String>,
 
     /// whether this event is an outlier (ie, whether we have the state at that
     /// point in the DAG)
@@ -232,6 +234,7 @@ impl EventInternalMetadata {
         Ok(EventInternalMetadata {
             data,
             stream_ordering: None,
+            instance_name: None,
             outlier: false,
         })
     }

scripts-dev/complement.sh

@@ -223,7 +223,6 @@ test_packages=(
     ./tests/msc3930
     ./tests/msc3902
     ./tests/msc3967
-    ./tests/msc4115
 )
 
 # Enable dirty runs, so tests will reuse the same container where possible.

synapse/api/constants.py

@@ -238,7 +238,7 @@ class EventUnsignedContentFields:
     """Fields found inside the 'unsigned' data on events"""
 
     # Requesting user's membership, per MSC4115
-    MSC4115_MEMBERSHIP: Final = "io.element.msc4115.membership"
+    MEMBERSHIP: Final = "membership"
 
 
 class RoomTypes:

synapse/config/experimental.py

@@ -436,10 +436,6 @@ class ExperimentalConfig(Config):
                 ("experimental", "msc4108_delegation_endpoint"),
             )
 
-        self.msc4115_membership_on_events = experimental.get(
-            "msc4115_membership_on_events", False
-        )
-
         self.msc3916_authenticated_media_enabled = experimental.get(
             "msc3916_authenticated_media_enabled", False
         )

synapse/events/utils.py

@@ -90,6 +90,7 @@ def prune_event(event: EventBase) -> EventBase:
     pruned_event.internal_metadata.stream_ordering = (
         event.internal_metadata.stream_ordering
     )
+    pruned_event.internal_metadata.instance_name = event.internal_metadata.instance_name
     pruned_event.internal_metadata.outlier = event.internal_metadata.outlier
 
     # Mark the event as redacted
@@ -116,6 +117,7 @@ def clone_event(event: EventBase) -> EventBase:
     new_event.internal_metadata.stream_ordering = (
         event.internal_metadata.stream_ordering
     )
+    new_event.internal_metadata.instance_name = event.internal_metadata.instance_name
     new_event.internal_metadata.outlier = event.internal_metadata.outlier
 
     return new_event

synapse/handlers/admin.py

@@ -42,7 +42,6 @@ class AdminHandler:
         self._device_handler = hs.get_device_handler()
         self._storage_controllers = hs.get_storage_controllers()
         self._state_storage_controller = self._storage_controllers.state
-        self._hs_config = hs.config
         self._msc3866_enabled = hs.config.experimental.msc3866.enabled
 
     async def get_whois(self, user: UserID) -> JsonMapping:
@@ -215,7 +214,6 @@ class AdminHandler:
                     self._storage_controllers,
                     user_id,
                     events,
-                    msc4115_membership_on_events=self._hs_config.experimental.msc4115_membership_on_events,
                 )
 
                 writer.write_events(room_id, events)

synapse/handlers/events.py

@@ -148,7 +148,6 @@ class EventHandler:
     def __init__(self, hs: "HomeServer"):
         self.store = hs.get_datastores().main
         self._storage_controllers = hs.get_storage_controllers()
-        self._config = hs.config
 
     async def get_event(
         self,
@@ -194,7 +193,6 @@ class EventHandler:
             user.to_string(),
             [event],
             is_peeking=is_peeking,
-            msc4115_membership_on_events=self._config.experimental.msc4115_membership_on_events,
         )
 
         if not filtered:

synapse/handlers/initial_sync.py

@@ -224,7 +224,6 @@ class InitialSyncHandler:
                     self._storage_controllers,
                     user_id,
                     messages,
-                    msc4115_membership_on_events=self.hs.config.experimental.msc4115_membership_on_events,
                 )
 
                 start_token = now_token.copy_and_replace(StreamKeyType.ROOM, token)
@@ -383,7 +382,6 @@ class InitialSyncHandler:
             requester.user.to_string(),
             messages,
             is_peeking=is_peeking,
-            msc4115_membership_on_events=self.hs.config.experimental.msc4115_membership_on_events,
         )
 
         start_token = StreamToken.START.copy_and_replace(StreamKeyType.ROOM, token)
@@ -498,7 +496,6 @@ class InitialSyncHandler:
             requester.user.to_string(),
             messages,
             is_peeking=is_peeking,
-            msc4115_membership_on_events=self.hs.config.experimental.msc4115_membership_on_events,
         )
 
         start_token = now_token.copy_and_replace(StreamKeyType.ROOM, token)

synapse/handlers/message.py

@@ -1551,6 +1551,7 @@ class EventCreationHandler:
                     # stream_ordering entry manually (as it was persisted on
                     # another worker).
                     event.internal_metadata.stream_ordering = stream_id
+                    event.internal_metadata.instance_name = writer_instance
 
                 return event
 

synapse/handlers/pagination.py

@@ -623,7 +623,6 @@ class PaginationHandler:
                 user_id,
                 events,
                 is_peeking=(member_event_id is None),
-                msc4115_membership_on_events=self.hs.config.experimental.msc4115_membership_on_events,
             )
 
         # if after the filter applied there are no more events

synapse/handlers/relations.py

@@ -95,7 +95,6 @@ class RelationsHandler:
         self._event_handler = hs.get_event_handler()
         self._event_serializer = hs.get_event_client_serializer()
         self._event_creation_handler = hs.get_event_creation_handler()
-        self._config = hs.config
 
     async def get_relations(
         self,
@@ -164,7 +163,6 @@ class RelationsHandler:
             user_id,
             events,
             is_peeking=(member_event_id is None),
-            msc4115_membership_on_events=self._config.experimental.msc4115_membership_on_events,
         )
 
         # The relations returned for the requested event do include their
@@ -610,7 +608,6 @@ class RelationsHandler:
             user_id,
             events,
             is_peeking=(member_event_id is None),
-            msc4115_membership_on_events=self._config.experimental.msc4115_membership_on_events,
         )
 
         aggregations = await self.get_bundled_aggregations(

synapse/handlers/room.py

@@ -1476,7 +1476,6 @@ class RoomContextHandler:
                 user.to_string(),
                 events,
                 is_peeking=is_peeking,
-                msc4115_membership_on_events=self.hs.config.experimental.msc4115_membership_on_events,
             )
 
         event = await self.store.get_event(

synapse/handlers/search.py

@@ -483,7 +483,6 @@ class SearchHandler:
             self._storage_controllers,
             user.to_string(),
             filtered_events,
-            msc4115_membership_on_events=self.hs.config.experimental.msc4115_membership_on_events,
         )
 
         events.sort(key=lambda e: -rank_map[e.event_id])
@@ -585,7 +584,6 @@ class SearchHandler:
                 self._storage_controllers,
                 user.to_string(),
                 filtered_events,
-                msc4115_membership_on_events=self.hs.config.experimental.msc4115_membership_on_events,
             )
 
             room_events.extend(events)
@@ -673,14 +671,12 @@ class SearchHandler:
                 self._storage_controllers,
                 user.to_string(),
                 res.events_before,
-                msc4115_membership_on_events=self.hs.config.experimental.msc4115_membership_on_events,
             )
 
             events_after = await filter_events_for_client(
                 self._storage_controllers,
                 user.to_string(),
                 res.events_after,
-                msc4115_membership_on_events=self.hs.config.experimental.msc4115_membership_on_events,
             )
 
             context: JsonDict = {

synapse/handlers/sliding_sync.py

@@ -22,7 +22,7 @@ from typing import TYPE_CHECKING, AbstractSet, Dict, List, Optional
 
 from immutabledict import immutabledict
 
-from synapse.api.constants import Membership
+from synapse.api.constants import AccountDataTypes, Membership
 from synapse.events import EventBase
 from synapse.types import Requester, RoomStreamToken, StreamToken, UserID
 from synapse.types.handlers import OperationType, SlidingSyncConfig, SlidingSyncResult
@@ -69,9 +69,19 @@ class SlidingSyncHandler:
         from_token: Optional[StreamToken] = None,
         timeout_ms: int = 0,
     ) -> SlidingSyncResult:
-        """Get the sync for a client if we have new data for it now. Otherwise
+        """
+        Get the sync for a client if we have new data for it now. Otherwise
         wait for new data to arrive on the server. If the timeout expires, then
         return an empty sync result.
+
+        Args:
+            requester: The user making the request
+            sync_config: Sync configuration
+            from_token: The point in the stream to sync from. Token of the end of the
+                previous batch. May be `None` if this is the initial sync request.
+            timeout_ms: The time in milliseconds to wait for new data to arrive. If 0,
+                we will immediately but there might not be any new data so we just return an
+                empty response.
         """
         # If the user is not part of the mau group, then check that limits have
         # not been exceeded (if not part of the group by this point, almost certain
@@ -143,6 +153,14 @@ class SlidingSyncHandler:
         """
         Generates the response body of a Sliding Sync result, represented as a
         `SlidingSyncResult`.
+
+        We fetch data according to the token range (> `from_token` and <= `to_token`).
+
+        Args:
+            sync_config: Sync configuration
+            to_token: The point in the stream to sync up to.
+            from_token: The point in the stream to sync from. Token of the end of the
+                previous batch. May be `None` if this is the initial sync request.
         """
         user_id = sync_config.user.to_string()
         app_service = self.store.get_app_service_by_user_id(user_id)
@@ -163,11 +181,12 @@ class SlidingSyncHandler:
         lists: Dict[str, SlidingSyncResult.SlidingWindowList] = {}
         if sync_config.lists:
             for list_key, list_config in sync_config.lists.items():
-                # TODO: Apply filters
-                #
-                # TODO: Exclude partially stated rooms unless the `required_state` has
-                # `["m.room.member", "$LAZY"]`
+                # Apply filters
                 filtered_room_ids = room_id_set
+                if list_config.filters is not None:
+                    filtered_room_ids = await self.filter_rooms(
+                        sync_config.user, room_id_set, list_config.filters, to_token
+                    )
                 # TODO: Apply sorts
                 sorted_room_ids = sorted(filtered_room_ids)
 
@@ -217,6 +236,12 @@ class SlidingSyncHandler:
           `forgotten` flag to the `room_memberships` table in Synapse. There isn't a way
           to tell when a room was forgotten at the moment so we can't factor it into the
           from/to range.
+
+
+        Args:
+            user: User to fetch rooms for
+            to_token: The token to fetch rooms up to.
+            from_token: The point in the stream to sync from.
         """
         user_id = user.to_string()
 
@@ -275,12 +300,6 @@ class SlidingSyncHandler:
             instance_map=immutabledict(instance_to_max_stream_ordering_map),
         )
 
-        # If our `to_token` is already the same or ahead of the latest room membership
-        # for the user, we can just straight-up return the room list (nothing has
-        # changed)
-        if membership_snapshot_token.is_before_or_eq(to_token.room_key):
-            return sync_room_id_set
-
         # Since we fetched 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`. In particular, we need to make these fixups:
@@ -300,14 +319,20 @@ class SlidingSyncHandler:
 
         # 1) Fetch membership changes that fall in the range from `to_token` up to
         # `membership_snapshot_token`
-        membership_change_events_after_to_token = (
-            await self.store.get_membership_changes_for_user(
-                user_id,
-                from_key=to_token.room_key,
-                to_key=membership_snapshot_token,
-                excluded_rooms=self.rooms_to_exclude_globally,
+        #
+        # 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 = []
+        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(
+                    user_id,
+                    from_key=to_token.room_key,
+                    to_key=membership_snapshot_token,
+                    excluded_rooms=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
@@ -439,3 +464,84 @@ class SlidingSyncHandler:
                 sync_room_id_set.add(room_id)
 
         return sync_room_id_set
+
+    async def filter_rooms(
+        self,
+        user: UserID,
+        room_id_set: AbstractSet[str],
+        filters: SlidingSyncConfig.SlidingSyncList.Filters,
+        to_token: StreamToken,
+    ) -> AbstractSet[str]:
+        """
+        Filter rooms based on the sync request.
+
+        Args:
+            user: User to filter rooms for
+            room_id_set: Set of room IDs to filter down
+            filters: Filters to apply
+            to_token: We filter based on the state of the room at this token
+        """
+        user_id = user.to_string()
+
+        # TODO: Apply filters
+        #
+        # TODO: Exclude partially stated rooms unless the `required_state` has
+        # `["m.room.member", "$LAZY"]`
+
+        filtered_room_id_set = set(room_id_set)
+
+        # Filter for Direct-Message (DM) rooms
+        if filters.is_dm is not None:
+            # We're using global account data (`m.direct`) instead of checking for
+            # `is_direct` on membership events because that property only appears for
+            # the invitee membership event (doesn't show up for the inviter). Account
+            # data is set by the client so it needs to be scrutinized.
+            #
+            # We're unable to take `to_token` into account for global account data since
+            # we only keep track of the latest account data for the user.
+            dm_map = await self.store.get_global_account_data_by_type_for_user(
+                user_id, AccountDataTypes.DIRECT
+            )
+
+            # Flatten out the map
+            dm_room_id_set = set()
+            if dm_map:
+                for room_ids in dm_map.values():
+                    # Account data should be a list of room IDs. Ignore anything else
+                    if isinstance(room_ids, list):
+                        for room_id in room_ids:
+                            if isinstance(room_id, str):
+                                dm_room_id_set.add(room_id)
+
+            if filters.is_dm:
+                # Only DM rooms please
+                filtered_room_id_set = filtered_room_id_set.intersection(dm_room_id_set)
+            else:
+                # Only non-DM rooms please
+                filtered_room_id_set = filtered_room_id_set.difference(dm_room_id_set)
+
+        if filters.spaces:
+            raise NotImplementedError()
+
+        if filters.is_encrypted:
+            raise NotImplementedError()
+
+        if filters.is_invite:
+            raise NotImplementedError()
+
+        if filters.room_types:
+            raise NotImplementedError()
+
+        if filters.not_room_types:
+            raise NotImplementedError()
+
+        if filters.room_name_like:
+            raise NotImplementedError()
+
+        if filters.tags:
+            raise NotImplementedError()
+
+        if filters.not_tags:
+            raise NotImplementedError()
+
+        return filtered_room_id_set

synapse/handlers/sync.py

@@ -844,7 +844,6 @@ class SyncHandler:
                     sync_config.user.to_string(),
                     recents,
                     always_include_ids=current_state_ids,
-                    msc4115_membership_on_events=self.hs_config.experimental.msc4115_membership_on_events,
                 )
                 log_kv({"recents_after_visibility_filtering": len(recents)})
             else:
@@ -930,7 +929,6 @@ class SyncHandler:
                     sync_config.user.to_string(),
                     loaded_recents,
                     always_include_ids=current_state_ids,
-                    msc4115_membership_on_events=self.hs_config.experimental.msc4115_membership_on_events,
                 )
 
                 loaded_recents = []

synapse/notifier.py

@@ -721,7 +721,6 @@ class Notifier:
                         user.to_string(),
                         new_events,
                         is_peeking=is_peeking,
-                        msc4115_membership_on_events=self.hs.config.experimental.msc4115_membership_on_events,
                     )
                 elif keyname == StreamKeyType.PRESENCE:
                     now = self.clock.time_msec()

synapse/push/mailer.py

@@ -532,7 +532,6 @@ class Mailer:
             self._storage_controllers,
             user_id,
             results.events_before,
-            msc4115_membership_on_events=self.hs.config.experimental.msc4115_membership_on_events,
         )
         the_events.append(notif_event)
 

synapse/rest/admin/rooms.py

@@ -35,6 +35,7 @@ from synapse.http.servlet import (
     ResolveRoomIdMixin,
     RestServlet,
     assert_params_in_dict,
+    parse_boolean,
     parse_enum,
     parse_integer,
     parse_json,
@@ -242,13 +243,23 @@ class ListRoomRestServlet(RestServlet):
                 errcode=Codes.INVALID_PARAM,
             )
 
+        public_rooms = parse_boolean(request, "public_rooms")
+        empty_rooms = parse_boolean(request, "empty_rooms")
+
         direction = parse_enum(request, "dir", Direction, default=Direction.FORWARDS)
         reverse_order = True if direction == Direction.BACKWARDS else False
 
         # Return list of rooms according to parameters
         rooms, total_rooms = await self.store.get_rooms_paginate(
-            start, limit, order_by, reverse_order, search_term
+            start,
+            limit,
+            order_by,
+            reverse_order,
+            search_term,
+            public_rooms,
+            empty_rooms,
         )
+
         response = {
             # next_token should be opaque, so return a value the client can parse
             "offset": start,

synapse/storage/databases/main/events.py

@@ -207,6 +207,7 @@ class PersistEventsStore:
         async with stream_ordering_manager as stream_orderings:
             for (event, _), stream in zip(events_and_contexts, stream_orderings):
                 event.internal_metadata.stream_ordering = stream
+                event.internal_metadata.instance_name = self._instance_name
 
             await self.db_pool.runInteraction(
                 "persist_events",

synapse/storage/databases/main/events_worker.py

@@ -156,6 +156,7 @@ class _EventRow:
 
     event_id: str
     stream_ordering: int
+    instance_name: str
     json: str
     internal_metadata: str
     format_version: Optional[int]
@@ -1354,6 +1355,7 @@ class EventsWorkerStore(SQLBaseStore):
                 rejected_reason=rejected_reason,
             )
             original_ev.internal_metadata.stream_ordering = row.stream_ordering
+            original_ev.internal_metadata.instance_name = row.instance_name
             original_ev.internal_metadata.outlier = row.outlier
 
             # Consistency check: if the content of the event has been modified in the
@@ -1439,6 +1441,7 @@ class EventsWorkerStore(SQLBaseStore):
                 SELECT
                   e.event_id,
                   e.stream_ordering,
+                  e.instance_name,
                   ej.internal_metadata,
                   ej.json,
                   ej.format_version,
@@ -1462,13 +1465,14 @@ class EventsWorkerStore(SQLBaseStore):
                 event_dict[event_id] = _EventRow(
                     event_id=event_id,
                     stream_ordering=row[1],
-                    internal_metadata=row[2],
-                    json=row[3],
-                    format_version=row[4],
-                    room_version_id=row[5],
-                    rejected_reason=row[6],
+                    instance_name=row[2],
+                    internal_metadata=row[3],
+                    json=row[4],
+                    format_version=row[5],
+                    room_version_id=row[6],
+                    rejected_reason=row[7],
                     redactions=[],
-                    outlier=bool(row[7]),  # This is an int in SQLite3
+                    outlier=bool(row[8]),  # This is an int in SQLite3
                 )
 
             # check for redactions

synapse/storage/databases/main/room.py

@@ -606,6 +606,8 @@ class RoomWorkerStore(CacheInvalidationWorkerStore):
         order_by: str,
         reverse_order: bool,
         search_term: Optional[str],
+        public_rooms: Optional[bool],
+        empty_rooms: Optional[bool],
     ) -> Tuple[List[Dict[str, Any]], int]:
         """Function to retrieve a paginated list of rooms as json.
 
@@ -617,30 +619,49 @@ class RoomWorkerStore(CacheInvalidationWorkerStore):
             search_term: a string to filter room names,
                 canonical alias and room ids by.
                 Room ID must match exactly. Canonical alias must match a substring of the local part.
+            public_rooms: Optional flag to filter public and non-public rooms. If true, public rooms are queried.
+                    if false, public rooms are excluded from the query. When it is
+                    none (the default), both public rooms and none-public-rooms are queried.
+            empty_rooms: Optional flag to filter empty and non-empty rooms.
+                    A room is empty if joined_members is zero.
+                    If true, empty rooms are queried.
+                    if false, empty rooms are excluded from the query. When it is
+                    none (the default), both empty rooms and none-empty rooms are queried.
         Returns:
             A list of room dicts and an integer representing the total number of
             rooms that exist given this query
         """
         # Filter room names by a string
-        where_statement = ""
-        search_pattern: List[object] = []
+        filter_ = []
+        where_args = []
         if search_term:
-            where_statement = """
-                WHERE LOWER(state.name) LIKE ?
-                OR LOWER(state.canonical_alias) LIKE ?
-                OR state.room_id = ?
-            """
+            filter_ = [
+                "LOWER(state.name) LIKE ? OR "
+                "LOWER(state.canonical_alias) LIKE ? OR "
+                "state.room_id = ?"
+            ]
 
             # Our postgres db driver converts ? -> %s in SQL strings as that's the
             # placeholder for postgres.
             # HOWEVER, if you put a % into your SQL then everything goes wibbly.
             # To get around this, we're going to surround search_term with %'s
             # before giving it to the database in python instead
-            search_pattern = [
-                "%" + search_term.lower() + "%",
-                "#%" + search_term.lower() + "%:%",
+            where_args = [
+                f"%{search_term.lower()}%",
+                f"#%{search_term.lower()}%:%",
                 search_term,
             ]
+        if public_rooms is not None:
+            filter_arg = "1" if public_rooms else "0"
+            filter_.append(f"rooms.is_public = '{filter_arg}'")
+
+        if empty_rooms is not None:
+            if empty_rooms:
+                filter_.append("curr.joined_members = 0")
+            else:
+                filter_.append("curr.joined_members <> 0")
+
+        where_clause = "WHERE " + " AND ".join(filter_) if len(filter_) > 0 else ""
 
         # Set ordering
         if RoomSortOrder(order_by) == RoomSortOrder.SIZE:
@@ -717,7 +738,7 @@ class RoomWorkerStore(CacheInvalidationWorkerStore):
             LIMIT ?
             OFFSET ?
         """.format(
-            where=where_statement,
+            where=where_clause,
             order_by=order_by_column,
             direction="ASC" if order_by_asc else "DESC",
         )
@@ -726,10 +747,12 @@ class RoomWorkerStore(CacheInvalidationWorkerStore):
         count_sql = """
             SELECT count(*) FROM (
               SELECT room_id FROM room_stats_state state
+              INNER JOIN room_stats_current curr USING (room_id)
+              INNER JOIN rooms USING (room_id)
               {where}
             ) AS get_room_ids
         """.format(
-            where=where_statement,
+            where=where_clause,
         )
 
         def _get_rooms_paginate_txn(
@@ -737,7 +760,7 @@ class RoomWorkerStore(CacheInvalidationWorkerStore):
         ) -> Tuple[List[Dict[str, Any]], int]:
             # Add the search term into the WHERE clause
             # and execute the data query
-            txn.execute(info_sql, search_pattern + [limit, start])
+            txn.execute(info_sql, where_args + [limit, start])
 
             # Refactor room query data into a structured dictionary
             rooms = []
@@ -767,7 +790,7 @@ class RoomWorkerStore(CacheInvalidationWorkerStore):
             # Execute the count query
 
             # Add the search term into the WHERE clause if present
-            txn.execute(count_sql, search_pattern)
+            txn.execute(count_sql, where_args)
 
             room_count = cast(Tuple[int], txn.fetchone())
             return rooms, room_count[0]

synapse/storage/databases/main/stream.py

@@ -914,12 +914,23 @@ class StreamWorkerStore(EventsWorkerStore, SQLBaseStore):
         def get_last_event_in_room_before_stream_ordering_txn(
             txn: LoggingTransaction,
         ) -> Optional[str]:
-            # We need to handle the fact that the stream tokens can be vector
-            # clocks. We do this by getting all rows between the minimum and
-            # maximum stream ordering in the token, plus one row less than the
-            # minimum stream ordering. We then filter the results against the
-            # token and return the first row that matches.
+            # We're looking for the closest event at or before the token. We need to
+            # handle the fact that the stream token can be a vector clock (with an
+            # `instance_map`) and events can be persisted on different instances
+            # (sharded event persisters). The first subquery handles the events that
+            # would be within the vector clock and gets all rows between the minimum and
+            # maximum stream ordering in the token which need to be filtered against the
+            # `instance_map`. The second subquery handles the "before" case and finds
+            # the first row before the token. We then filter out any results past the
+            # token's vector clock and return the first row that matches.
+            min_stream = end_token.stream
+            max_stream = end_token.get_max_stream_pos()
 
+            # We use `union all` because we don't need any of the deduplication logic
+            # (`union` is really a union + distinct). `UNION ALL` does preserve the
+            # ordering of the operand queries but there is no actual gurantee that it
+            # has this behavior in all scenarios so we need the extra `ORDER BY` at the
+            # bottom.
             sql = """
                 SELECT * FROM (
                     SELECT instance_name, stream_ordering, topological_ordering, event_id
@@ -931,7 +942,7 @@ class StreamWorkerStore(EventsWorkerStore, SQLBaseStore):
                         AND rejections.event_id IS NULL
                     ORDER BY stream_ordering DESC
                 ) AS a
-                UNION
+                UNION ALL
                 SELECT * FROM (
                     SELECT instance_name, stream_ordering, topological_ordering, event_id
                     FROM events
@@ -943,15 +954,16 @@ class StreamWorkerStore(EventsWorkerStore, SQLBaseStore):
                     ORDER BY stream_ordering DESC
                     LIMIT 1
                 ) AS b
+                ORDER BY stream_ordering DESC
             """
             txn.execute(
                 sql,
                 (
                     room_id,
-                    end_token.stream,
-                    end_token.get_max_stream_pos(),
+                    min_stream,
+                    max_stream,
                     room_id,
-                    end_token.stream,
+                    min_stream,
                 ),
             )
 

synapse/synapse_rust/events.pyi

@@ -19,6 +19,8 @@ class EventInternalMetadata:
 
     stream_ordering: Optional[int]
     """the stream ordering of this event. None, until it has been persisted."""
+    instance_name: Optional[str]
+    """the instance name of the server that persisted this event. None, until it has been persisted."""
 
     outlier: bool
     """whether this event is an outlier (ie, whether we have the state at that

synapse/types/rest/client/__init__.py

@@ -238,6 +238,53 @@ class SlidingSyncBody(RequestBodyModel):
         """
 
         class Filters(RequestBodyModel):
+            """
+            All fields are applied with AND operators, hence if `is_dm: True` and
+            `is_encrypted: True` then only Encrypted DM rooms will be returned. The
+            absence of fields implies no filter on that criteria: it does NOT imply
+            `False`. These fields may be expanded through use of extensions.
+
+            Attributes:
+                is_dm: Flag which only returns rooms present (or not) in the DM section
+                    of account data. If unset, both DM rooms and non-DM rooms are returned.
+                    If False, only non-DM rooms are returned. If True, only DM rooms are
+                    returned.
+                spaces: Filter the room based on the space they belong to according to
+                    `m.space.child` state events. If multiple spaces are present, a room can
+                    be part of any one of the listed spaces (OR'd). The server will inspect
+                    the `m.space.child` state events for the JOINED space room IDs given.
+                    Servers MUST NOT navigate subspaces. It is up to the client to give a
+                    complete list of spaces to navigate. Only rooms directly mentioned as
+                    `m.space.child` events in these spaces will be returned. Unknown spaces
+                    or spaces the user is not joined to will be ignored.
+                is_encrypted: Flag which only returns rooms which have an
+                    `m.room.encryption` state event. If unset, both encrypted and
+                    unencrypted rooms are returned. If `False`, only unencrypted rooms are
+                    returned. If `True`, only encrypted rooms are returned.
+                is_invite: Flag which only returns rooms the user is currently invited
+                    to. If unset, both invited and joined rooms are returned. If `False`, no
+                    invited rooms are returned. If `True`, only invited rooms are returned.
+                room_types: If specified, only rooms where the `m.room.create` event has
+                    a `type` matching one of the strings in this array will be returned. If
+                    this field is unset, all rooms are returned regardless of type. This can
+                    be used to get the initial set of spaces for an account. For rooms which
+                    do not have a room type, use `null`/`None` to include them.
+                not_room_types: Same as `room_types` but inverted. This can be used to
+                    filter out spaces from the room list. If a type is in both `room_types`
+                    and `not_room_types`, then `not_room_types` wins and they are not included
+                    in the result.
+                room_name_like: Filter the room name. Case-insensitive partial matching
+                    e.g 'foo' matches 'abFooab'. The term 'like' is inspired by SQL 'LIKE',
+                    and the text here is similar to '%foo%'.
+                tags: Filter the room based on its room tags. If multiple tags are
+                    present, a room can have any one of the listed tags (OR'd).
+                not_tags: Filter the room based on its room tags. Takes priority over
+                    `tags`. For example, a room with tags A and B with filters `tags: [A]`
+                    `not_tags: [B]` would NOT be included because `not_tags` takes priority over
+                    `tags`. This filter is useful if your rooms list does NOT include the
+                    list of favourite rooms again.
+            """
+
             is_dm: Optional[StrictBool] = None
             spaces: Optional[List[StrictStr]] = None
             is_encrypted: Optional[StrictBool] = None

synapse/visibility.py

@@ -82,7 +82,6 @@ async def filter_events_for_client(
     is_peeking: bool = False,
     always_include_ids: FrozenSet[str] = frozenset(),
     filter_send_to_client: bool = True,
-    msc4115_membership_on_events: bool = False,
 ) -> List[EventBase]:
     """
     Check which events a user is allowed to see. If the user can see the event but its
@@ -101,12 +100,10 @@ async def filter_events_for_client(
         filter_send_to_client: Whether we're checking an event that's going to be
             sent to a client. This might not always be the case since this function can
             also be called to check whether a user can see the state at a given point.
-        msc4115_membership_on_events: Whether to include the requesting user's
-            membership in the "unsigned" data, per MSC4115.
 
     Returns:
-        The filtered events. If `msc4115_membership_on_events` is true, the `unsigned`
-        data is annotated with the membership state of `user_id` at each event.
+        The filtered events. The `unsigned` data is annotated with the membership state
+        of `user_id` at each event.
     """
     # Filter out events that have been soft failed so that we don't relay them
     # to clients.
@@ -159,9 +156,6 @@ async def filter_events_for_client(
         if filtered is None:
             return None
 
-        if not msc4115_membership_on_events:
-            return filtered
-
         # Annotate the event with the user's membership after the event.
         #
         # Normally we just look in `state_after_event`, but if the event is an outlier
@@ -186,7 +180,7 @@ async def filter_events_for_client(
         # Copy the event before updating the unsigned data: this shouldn't be persisted
         # to the cache!
         cloned = clone_event(filtered)
-        cloned.unsigned[EventUnsignedContentFields.MSC4115_MEMBERSHIP] = user_membership
+        cloned.unsigned[EventUnsignedContentFields.MEMBERSHIP] = user_membership
 
         return cloned
 

tests/events/test_utils.py

@@ -625,6 +625,8 @@ class CloneEventTestCase(stdlib_unittest.TestCase):
         )
         original.internal_metadata.stream_ordering = 1234
         self.assertEqual(original.internal_metadata.stream_ordering, 1234)
+        original.internal_metadata.instance_name = "worker1"
+        self.assertEqual(original.internal_metadata.instance_name, "worker1")
 
         cloned = clone_event(original)
         cloned.unsigned["b"] = 3
@@ -632,6 +634,7 @@ class CloneEventTestCase(stdlib_unittest.TestCase):
         self.assertEqual(original.unsigned, {"a": 1, "b": 2})
         self.assertEqual(cloned.unsigned, {"a": 1, "b": 3})
         self.assertEqual(cloned.internal_metadata.stream_ordering, 1234)
+        self.assertEqual(cloned.internal_metadata.instance_name, "worker1")
         self.assertEqual(cloned.internal_metadata.txn_id, "txn")
 
 

tests/handlers/test_sliding_sync.py

@@ -22,8 +22,9 @@ from unittest.mock import patch
 
 from twisted.test.proto_helpers import MemoryReactor
 
-from synapse.api.constants import EventTypes, JoinRules, Membership
+from synapse.api.constants import AccountDataTypes, EventTypes, JoinRules, Membership
 from synapse.api.room_versions import RoomVersions
+from synapse.handlers.sliding_sync import SlidingSyncConfig
 from synapse.rest import admin
 from synapse.rest.client import knock, login, room
 from synapse.server import HomeServer
@@ -326,7 +327,7 @@ class GetSyncRoomIdsForUserTestCase(HomeserverTestCase):
 
         # Leave during the from_token/to_token range (newly_left)
         room_id2 = self.helper.create_room_as(user1_id, tok=user1_tok)
-        self.helper.leave(room_id1, user1_id, tok=user1_tok)
+        self.helper.leave(room_id2, user1_id, tok=user1_tok)
 
         after_room2_token = self.event_sources.get_current_token()
 
@@ -1116,3 +1117,130 @@ class GetSyncRoomIdsForUserEventShardTestCase(BaseMultiWorkerStreamTestCase):
                 room_id3,
             },
         )
+
+
+class FilterRoomsTestCase(HomeserverTestCase):
+    """
+    Tests Sliding Sync handler `filter_rooms()` to make sure it includes/excludes rooms
+    correctly.
+    """
+
+    servlets = [
+        admin.register_servlets,
+        knock.register_servlets,
+        login.register_servlets,
+        room.register_servlets,
+    ]
+
+    def default_config(self) -> JsonDict:
+        config = super().default_config()
+        # Enable sliding sync
+        config["experimental_features"] = {"msc3575_enabled": True}
+        return config
+
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
+        self.sliding_sync_handler = self.hs.get_sliding_sync_handler()
+        self.store = self.hs.get_datastores().main
+        self.event_sources = hs.get_event_sources()
+
+    def _create_dm_room(
+        self,
+        inviter_user_id: str,
+        inviter_tok: str,
+        invitee_user_id: str,
+        invitee_tok: str,
+    ) -> str:
+        """
+        Helper to create a DM room as the "inviter" and invite the "invitee" user to the room. The
+        "invitee" user also will join the room. The `m.direct` account data will be set
+        for both users.
+        """
+
+        # Create a room and send an invite the other user
+        room_id = self.helper.create_room_as(
+            inviter_user_id,
+            is_public=False,
+            tok=inviter_tok,
+        )
+        self.helper.invite(
+            room_id,
+            src=inviter_user_id,
+            targ=invitee_user_id,
+            tok=inviter_tok,
+            extra_data={"is_direct": True},
+        )
+        # Person that was invited joins the room
+        self.helper.join(room_id, invitee_user_id, tok=invitee_tok)
+
+        # Mimic the client setting the room as a direct message in the global account
+        # data
+        self.get_success(
+            self.store.add_account_data_for_user(
+                invitee_user_id,
+                AccountDataTypes.DIRECT,
+                {inviter_user_id: [room_id]},
+            )
+        )
+        self.get_success(
+            self.store.add_account_data_for_user(
+                inviter_user_id,
+                AccountDataTypes.DIRECT,
+                {invitee_user_id: [room_id]},
+            )
+        )
+
+        return room_id
+
+    def test_filter_dm_rooms(self) -> None:
+        """
+        Test `filter.is_dm` for DM rooms
+        """
+        user1_id = self.register_user("user1", "pass")
+        user1_tok = self.login(user1_id, "pass")
+        user2_id = self.register_user("user2", "pass")
+        user2_tok = self.login(user2_id, "pass")
+
+        # Create a normal room
+        room_id = self.helper.create_room_as(
+            user1_id,
+            is_public=False,
+            tok=user1_tok,
+        )
+
+        # Create a DM room
+        dm_room_id = self._create_dm_room(
+            inviter_user_id=user1_id,
+            inviter_tok=user1_tok,
+            invitee_user_id=user2_id,
+            invitee_tok=user2_tok,
+        )
+
+        after_rooms_token = self.event_sources.get_current_token()
+
+        # Try with `is_dm=True`
+        truthy_filtered_room_ids = self.get_success(
+            self.sliding_sync_handler.filter_rooms(
+                UserID.from_string(user1_id),
+                {room_id, dm_room_id},
+                SlidingSyncConfig.SlidingSyncList.Filters(
+                    is_dm=True,
+                ),
+                after_rooms_token,
+            )
+        )
+
+        self.assertEqual(truthy_filtered_room_ids, {dm_room_id})
+
+        # Try with `is_dm=False`
+        falsy_filtered_room_ids = self.get_success(
+            self.sliding_sync_handler.filter_rooms(
+                UserID.from_string(user1_id),
+                {room_id, dm_room_id},
+                SlidingSyncConfig.SlidingSyncList.Filters(
+                    is_dm=False,
+                ),
+                after_rooms_token,
+            )
+        )
+
+        self.assertEqual(falsy_filtered_room_ids, {room_id})

tests/replication/storage/test_events.py

@@ -141,6 +141,7 @@ class EventsWorkerStoreTestCase(BaseWorkerStoreTestCase):
         self.persist(type="m.room.create", key="", creator=USER_ID)
         self.check("get_invited_rooms_for_local_user", [USER_ID_2], [])
         event = self.persist(type="m.room.member", key=USER_ID_2, membership="invite")
+        assert event.internal_metadata.instance_name is not None
         assert event.internal_metadata.stream_ordering is not None
 
         self.replicate()
@@ -155,7 +156,7 @@ class EventsWorkerStoreTestCase(BaseWorkerStoreTestCase):
                     "invite",
                     event.event_id,
                     PersistedEventPosition(
-                        self.hs.get_instance_name(),
+                        event.internal_metadata.instance_name,
                         event.internal_metadata.stream_ordering,
                     ),
                     RoomVersions.V1.identifier,
@@ -232,11 +233,12 @@ class EventsWorkerStoreTestCase(BaseWorkerStoreTestCase):
         j2 = self.persist(
             type="m.room.member", sender=USER_ID_2, key=USER_ID_2, membership="join"
         )
+        assert j2.internal_metadata.instance_name is not None
         assert j2.internal_metadata.stream_ordering is not None
         self.replicate()
 
         expected_pos = PersistedEventPosition(
-            "master", j2.internal_metadata.stream_ordering
+            j2.internal_metadata.instance_name, j2.internal_metadata.stream_ordering
         )
         self.check(
             "get_rooms_for_user_with_stream_ordering",
@@ -288,6 +290,7 @@ class EventsWorkerStoreTestCase(BaseWorkerStoreTestCase):
         msg, msgctx = self.build_event()
         self.get_success(self.persistance.persist_events([(j2, j2ctx), (msg, msgctx)]))
         self.replicate()
+        assert j2.internal_metadata.instance_name is not None
         assert j2.internal_metadata.stream_ordering is not None
 
         event_source = RoomEventSource(self.hs)
@@ -329,7 +332,8 @@ class EventsWorkerStoreTestCase(BaseWorkerStoreTestCase):
             # joined_rooms list.
             if membership_changes:
                 expected_pos = PersistedEventPosition(
-                    "master", j2.internal_metadata.stream_ordering
+                    j2.internal_metadata.instance_name,
+                    j2.internal_metadata.stream_ordering,
                 )
                 self.assertEqual(
                     joined_rooms,

tests/rest/admin/test_room.py

@@ -1795,6 +1795,83 @@ class RoomTestCase(unittest.HomeserverTestCase):
         self.assertEqual(room_id, channel.json_body["rooms"][0].get("room_id"))
         self.assertEqual("ж", channel.json_body["rooms"][0].get("name"))
 
+    def test_filter_public_rooms(self) -> None:
+        self.helper.create_room_as(
+            self.admin_user, tok=self.admin_user_tok, is_public=True
+        )
+        self.helper.create_room_as(
+            self.admin_user, tok=self.admin_user_tok, is_public=True
+        )
+        self.helper.create_room_as(
+            self.admin_user, tok=self.admin_user_tok, is_public=False
+        )
+
+        response = self.make_request(
+            "GET",
+            "/_synapse/admin/v1/rooms",
+            access_token=self.admin_user_tok,
+        )
+        self.assertEqual(200, response.code, msg=response.json_body)
+        self.assertEqual(3, response.json_body["total_rooms"])
+        self.assertEqual(3, len(response.json_body["rooms"]))
+
+        response = self.make_request(
+            "GET",
+            "/_synapse/admin/v1/rooms?public_rooms=true",
+            access_token=self.admin_user_tok,
+        )
+        self.assertEqual(200, response.code, msg=response.json_body)
+        self.assertEqual(2, response.json_body["total_rooms"])
+        self.assertEqual(2, len(response.json_body["rooms"]))
+
+        response = self.make_request(
+            "GET",
+            "/_synapse/admin/v1/rooms?public_rooms=false",
+            access_token=self.admin_user_tok,
+        )
+        self.assertEqual(200, response.code, msg=response.json_body)
+        self.assertEqual(1, response.json_body["total_rooms"])
+        self.assertEqual(1, len(response.json_body["rooms"]))
+
+    def test_filter_empty_rooms(self) -> None:
+        self.helper.create_room_as(
+            self.admin_user, tok=self.admin_user_tok, is_public=True
+        )
+        self.helper.create_room_as(
+            self.admin_user, tok=self.admin_user_tok, is_public=True
+        )
+        room_id = self.helper.create_room_as(
+            self.admin_user, tok=self.admin_user_tok, is_public=False
+        )
+        self.helper.leave(room_id, self.admin_user, tok=self.admin_user_tok)
+
+        response = self.make_request(
+            "GET",
+            "/_synapse/admin/v1/rooms",
+            access_token=self.admin_user_tok,
+        )
+        self.assertEqual(200, response.code, msg=response.json_body)
+        self.assertEqual(3, response.json_body["total_rooms"])
+        self.assertEqual(3, len(response.json_body["rooms"]))
+
+        response = self.make_request(
+            "GET",
+            "/_synapse/admin/v1/rooms?empty_rooms=false",
+            access_token=self.admin_user_tok,
+        )
+        self.assertEqual(200, response.code, msg=response.json_body)
+        self.assertEqual(2, response.json_body["total_rooms"])
+        self.assertEqual(2, len(response.json_body["rooms"]))
+
+        response = self.make_request(
+            "GET",
+            "/_synapse/admin/v1/rooms?empty_rooms=true",
+            access_token=self.admin_user_tok,
+        )
+        self.assertEqual(200, response.code, msg=response.json_body)
+        self.assertEqual(1, response.json_body["total_rooms"])
+        self.assertEqual(1, len(response.json_body["rooms"]))
+
     def test_single_room(self) -> None:
         """Test that a single room can be requested correctly"""
         # Create two test rooms

tests/rest/client/test_retention.py

@@ -167,7 +167,6 @@ class RetentionTestCase(unittest.HomeserverTestCase):
                 storage_controllers,
                 self.user_id,
                 events,
-                msc4115_membership_on_events=True,
             )
         )
 

tests/rest/client/test_sync.py

@@ -27,6 +27,7 @@ from twisted.test.proto_helpers import MemoryReactor
 
 import synapse.rest.admin
 from synapse.api.constants import (
+    AccountDataTypes,
     EventContentFields,
     EventTypes,
     ReceiptTypes,
@@ -1226,10 +1227,59 @@ class SlidingSyncTestCase(unittest.HomeserverTestCase):
         return config
 
     def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
+        self.store = hs.get_datastores().main
         self.sync_endpoint = "/_matrix/client/unstable/org.matrix.msc3575/sync"
         self.store = hs.get_datastores().main
         self.event_sources = hs.get_event_sources()
 
+    def _create_dm_room(
+        self,
+        inviter_user_id: str,
+        inviter_tok: str,
+        invitee_user_id: str,
+        invitee_tok: str,
+    ) -> str:
+        """
+        Helper to create a DM room as the "inviter" and invite the "invitee" user to the
+        room. The "invitee" user also will join the room. The `m.direct` account data
+        will be set for both users.
+        """
+
+        # Create a room and send an invite the other user
+        room_id = self.helper.create_room_as(
+            inviter_user_id,
+            is_public=False,
+            tok=inviter_tok,
+        )
+        self.helper.invite(
+            room_id,
+            src=inviter_user_id,
+            targ=invitee_user_id,
+            tok=inviter_tok,
+            extra_data={"is_direct": True},
+        )
+        # Person that was invited joins the room
+        self.helper.join(room_id, invitee_user_id, tok=invitee_tok)
+
+        # Mimic the client setting the room as a direct message in the global account
+        # data
+        self.get_success(
+            self.store.add_account_data_for_user(
+                invitee_user_id,
+                AccountDataTypes.DIRECT,
+                {inviter_user_id: [room_id]},
+            )
+        )
+        self.get_success(
+            self.store.add_account_data_for_user(
+                inviter_user_id,
+                AccountDataTypes.DIRECT,
+                {invitee_user_id: [room_id]},
+            )
+        )
+
+        return room_id
+
     def test_sync_list(self) -> None:
         """
         Test that room IDs show up in the Sliding Sync lists
@@ -1336,3 +1386,80 @@ class SlidingSyncTestCase(unittest.HomeserverTestCase):
         self.assertEqual(
             channel.json_body["next_pos"], future_position_token_serialized
         )
+
+    def test_filter_list(self) -> None:
+        """
+        Test that filters apply to lists
+        """
+        user1_id = self.register_user("user1", "pass")
+        user1_tok = self.login(user1_id, "pass")
+        user2_id = self.register_user("user2", "pass")
+        user2_tok = self.login(user2_id, "pass")
+
+        # Create a DM room
+        dm_room_id = self._create_dm_room(
+            inviter_user_id=user1_id,
+            inviter_tok=user1_tok,
+            invitee_user_id=user2_id,
+            invitee_tok=user2_tok,
+        )
+
+        # Create a normal room
+        room_id = self.helper.create_room_as(user1_id, tok=user1_tok, is_public=True)
+
+        # Make the Sliding Sync request
+        channel = self.make_request(
+            "POST",
+            self.sync_endpoint,
+            {
+                "lists": {
+                    "dms": {
+                        "ranges": [[0, 99]],
+                        "sort": ["by_recency"],
+                        "required_state": [],
+                        "timeline_limit": 1,
+                        "filters": {"is_dm": True},
+                    },
+                    "foo-list": {
+                        "ranges": [[0, 99]],
+                        "sort": ["by_recency"],
+                        "required_state": [],
+                        "timeline_limit": 1,
+                        "filters": {"is_dm": False},
+                    },
+                }
+            },
+            access_token=user1_tok,
+        )
+        self.assertEqual(channel.code, 200, channel.json_body)
+
+        # Make sure it has the foo-list we requested
+        self.assertListEqual(
+            list(channel.json_body["lists"].keys()),
+            ["dms", "foo-list"],
+            channel.json_body["lists"].keys(),
+        )
+
+        # Make sure the list includes the room we are joined to
+        self.assertListEqual(
+            list(channel.json_body["lists"]["dms"]["ops"]),
+            [
+                {
+                    "op": "SYNC",
+                    "range": [0, 99],
+                    "room_ids": [dm_room_id],
+                }
+            ],
+            list(channel.json_body["lists"]["dms"]),
+        )
+        self.assertListEqual(
+            list(channel.json_body["lists"]["foo-list"]["ops"]),
+            [
+                {
+                    "op": "SYNC",
+                    "range": [0, 99],
+                    "room_ids": [room_id],
+                }
+            ],
+            list(channel.json_body["lists"]["foo-list"]),
+        )

tests/storage/test_event_chain.py

@@ -431,6 +431,7 @@ class EventChainStoreTestCase(HomeserverTestCase):
 
         for e in events:
             e.internal_metadata.stream_ordering = self._next_stream_ordering
+            e.internal_metadata.instance_name = self.hs.get_instance_name()
             self._next_stream_ordering += 1
 
         def _persist(txn: LoggingTransaction) -> None:

tests/storage/test_stream.py

@@ -19,7 +19,10 @@
 #
 #
 
-from typing import List
+import logging
+from typing import List, Tuple
+
+from immutabledict import immutabledict
 
 from twisted.test.proto_helpers import MemoryReactor
 
@@ -28,11 +31,13 @@ from synapse.api.filtering import Filter
 from synapse.rest import admin
 from synapse.rest.client import login, room
 from synapse.server import HomeServer
-from synapse.types import JsonDict
+from synapse.types import JsonDict, PersistedEventPosition, RoomStreamToken
 from synapse.util import Clock
 
 from tests.unittest import HomeserverTestCase
 
+logger = logging.getLogger(__name__)
+
 
 class PaginationTestCase(HomeserverTestCase):
     """
@@ -268,3 +273,263 @@ class PaginationTestCase(HomeserverTestCase):
         }
         chunk = self._filter_messages(filter)
         self.assertEqual(chunk, [self.event_id_1, self.event_id_2, self.event_id_none])
+
+
+class GetLastEventInRoomBeforeStreamOrderingTestCase(HomeserverTestCase):
+    """
+    Test `get_last_event_in_room_before_stream_ordering(...)`
+    """
+
+    servlets = [
+        admin.register_servlets,
+        room.register_servlets,
+        login.register_servlets,
+    ]
+
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
+        self.store = hs.get_datastores().main
+        self.event_sources = hs.get_event_sources()
+
+    def _update_persisted_instance_name_for_event(
+        self, event_id: str, instance_name: str
+    ) -> None:
+        """
+        Update the `instance_name` that persisted the the event in the database.
+        """
+        return self.get_success(
+            self.store.db_pool.simple_update_one(
+                "events",
+                keyvalues={"event_id": event_id},
+                updatevalues={"instance_name": instance_name},
+            )
+        )
+
+    def _send_event_on_instance(
+        self, instance_name: str, room_id: str, access_token: str
+    ) -> Tuple[JsonDict, PersistedEventPosition]:
+        """
+        Send an event in a room and mimic that it was persisted by a specific
+        instance/worker.
+        """
+        event_response = self.helper.send(
+            room_id, f"{instance_name} message", tok=access_token
+        )
+
+        self._update_persisted_instance_name_for_event(
+            event_response["event_id"], instance_name
+        )
+
+        event_pos = self.get_success(
+            self.store.get_position_for_event(event_response["event_id"])
+        )
+
+        return event_response, event_pos
+
+    def test_before_room_created(self) -> None:
+        """
+        Test that no event is returned if we are using a token before the room was even created
+        """
+        user1_id = self.register_user("user1", "pass")
+        user1_tok = self.login(user1_id, "pass")
+
+        before_room_token = self.event_sources.get_current_token()
+
+        room_id = self.helper.create_room_as(user1_id, tok=user1_tok, is_public=True)
+
+        last_event = self.get_success(
+            self.store.get_last_event_in_room_before_stream_ordering(
+                room_id=room_id,
+                end_token=before_room_token.room_key,
+            )
+        )
+
+        self.assertIsNone(last_event)
+
+    def test_after_room_created(self) -> None:
+        """
+        Test that an event is returned if we are using a token after the room was created
+        """
+        user1_id = self.register_user("user1", "pass")
+        user1_tok = self.login(user1_id, "pass")
+
+        room_id = self.helper.create_room_as(user1_id, tok=user1_tok, is_public=True)
+
+        after_room_token = self.event_sources.get_current_token()
+
+        last_event = self.get_success(
+            self.store.get_last_event_in_room_before_stream_ordering(
+                room_id=room_id,
+                end_token=after_room_token.room_key,
+            )
+        )
+
+        self.assertIsNotNone(last_event)
+
+    def test_activity_in_other_rooms(self) -> None:
+        """
+        Test to make sure that the last event in the room is returned even if the
+        `stream_ordering` has advanced from activity in other rooms.
+        """
+        user1_id = self.register_user("user1", "pass")
+        user1_tok = self.login(user1_id, "pass")
+
+        room_id1 = self.helper.create_room_as(user1_id, tok=user1_tok, is_public=True)
+        event_response = self.helper.send(room_id1, "target!", tok=user1_tok)
+        # Create another room to advance the stream_ordering
+        self.helper.create_room_as(user1_id, tok=user1_tok, is_public=True)
+
+        after_room_token = self.event_sources.get_current_token()
+
+        last_event = self.get_success(
+            self.store.get_last_event_in_room_before_stream_ordering(
+                room_id=room_id1,
+                end_token=after_room_token.room_key,
+            )
+        )
+
+        # Make sure it's the event we expect (which also means we know it's from the
+        # correct room)
+        self.assertEqual(last_event, event_response["event_id"])
+
+    def test_activity_after_token_has_no_effect(self) -> None:
+        """
+        Test to make sure we return the last event before the token even if there is
+        activity after it.
+        """
+        user1_id = self.register_user("user1", "pass")
+        user1_tok = self.login(user1_id, "pass")
+
+        room_id1 = self.helper.create_room_as(user1_id, tok=user1_tok, is_public=True)
+        event_response = self.helper.send(room_id1, "target!", tok=user1_tok)
+
+        after_room_token = self.event_sources.get_current_token()
+
+        # Send some events after the token
+        self.helper.send(room_id1, "after1", tok=user1_tok)
+        self.helper.send(room_id1, "after2", tok=user1_tok)
+
+        last_event = self.get_success(
+            self.store.get_last_event_in_room_before_stream_ordering(
+                room_id=room_id1,
+                end_token=after_room_token.room_key,
+            )
+        )
+
+        # Make sure it's the last event before the token
+        self.assertEqual(last_event, event_response["event_id"])
+
+    def test_last_event_within_sharded_token(self) -> None:
+        """
+        Test to make sure we can find the last event that that is *within* the sharded
+        token (a token that has an `instance_map` and looks like
+        `m{min_pos}~{writer1}.{pos1}~{writer2}.{pos2}`). We are specifically testing
+        that we can find an event within the tokens minimum and instance
+        `stream_ordering`.
+        """
+        user1_id = self.register_user("user1", "pass")
+        user1_tok = self.login(user1_id, "pass")
+
+        room_id1 = self.helper.create_room_as(user1_id, tok=user1_tok, is_public=True)
+        event_response1, event_pos1 = self._send_event_on_instance(
+            "worker1", room_id1, user1_tok
+        )
+        event_response2, event_pos2 = self._send_event_on_instance(
+            "worker1", room_id1, user1_tok
+        )
+        event_response3, event_pos3 = self._send_event_on_instance(
+            "worker1", room_id1, user1_tok
+        )
+
+        # Create another room to advance the `stream_ordering` on the same worker
+        # so we can sandwich event3 in the middle of the token
+        room_id2 = self.helper.create_room_as(user1_id, tok=user1_tok, is_public=True)
+        event_response4, event_pos4 = self._send_event_on_instance(
+            "worker1", room_id2, user1_tok
+        )
+
+        # Assemble a token that encompasses event1 -> event4 on worker1
+        end_token = RoomStreamToken(
+            stream=event_pos2.stream,
+            instance_map=immutabledict({"worker1": event_pos4.stream}),
+        )
+
+        # Send some events after the token
+        self.helper.send(room_id1, "after1", tok=user1_tok)
+        self.helper.send(room_id1, "after2", tok=user1_tok)
+
+        last_event = self.get_success(
+            self.store.get_last_event_in_room_before_stream_ordering(
+                room_id=room_id1,
+                end_token=end_token,
+            )
+        )
+
+        # Should find closest event at/before the token in room1
+        self.assertEqual(
+            last_event,
+            event_response3["event_id"],
+            f"We expected {event_response3['event_id']} but saw {last_event} which corresponds to "
+            + str(
+                {
+                    "event1": event_response1["event_id"],
+                    "event2": event_response2["event_id"],
+                    "event3": event_response3["event_id"],
+                }
+            ),
+        )
+
+    def test_last_event_before_sharded_token(self) -> None:
+        """
+        Test to make sure we can find the last event that is *before* the sharded token
+        (a token that has an `instance_map` and looks like
+        `m{min_pos}~{writer1}.{pos1}~{writer2}.{pos2}`).
+        """
+        user1_id = self.register_user("user1", "pass")
+        user1_tok = self.login(user1_id, "pass")
+
+        room_id1 = self.helper.create_room_as(user1_id, tok=user1_tok, is_public=True)
+        event_response1, event_pos1 = self._send_event_on_instance(
+            "worker1", room_id1, user1_tok
+        )
+        event_response2, event_pos2 = self._send_event_on_instance(
+            "worker1", room_id1, user1_tok
+        )
+
+        # Create another room to advance the `stream_ordering` on the same worker
+        room_id2 = self.helper.create_room_as(user1_id, tok=user1_tok, is_public=True)
+        event_response3, event_pos3 = self._send_event_on_instance(
+            "worker1", room_id2, user1_tok
+        )
+        event_response4, event_pos4 = self._send_event_on_instance(
+            "worker1", room_id2, user1_tok
+        )
+
+        # Assemble a token that encompasses event3 -> event4 on worker1
+        end_token = RoomStreamToken(
+            stream=event_pos3.stream,
+            instance_map=immutabledict({"worker1": event_pos4.stream}),
+        )
+
+        # Send some events after the token
+        self.helper.send(room_id1, "after1", tok=user1_tok)
+        self.helper.send(room_id1, "after2", tok=user1_tok)
+
+        last_event = self.get_success(
+            self.store.get_last_event_in_room_before_stream_ordering(
+                room_id=room_id1,
+                end_token=end_token,
+            )
+        )
+
+        # Should find closest event at/before the token in room1
+        self.assertEqual(
+            last_event,
+            event_response2["event_id"],
+            f"We expected {event_response2['event_id']} but saw {last_event} which corresponds to "
+            + str(
+                {
+                    "event1": event_response1["event_id"],
+                    "event2": event_response2["event_id"],
+                }
+            ),
+        )

tests/test_visibility.py

@@ -336,7 +336,6 @@ class FilterEventsForClientTestCase(HomeserverTestCase):
                 self.hs.get_storage_controllers(),
                 "@joiner:test",
                 events_to_filter,
-                msc4115_membership_on_events=True,
             )
         )
         resident_filtered_events = self.get_success(
@@ -344,7 +343,6 @@ class FilterEventsForClientTestCase(HomeserverTestCase):
                 self.hs.get_storage_controllers(),
                 "@resident:test",
                 events_to_filter,
-                msc4115_membership_on_events=True,
             )
         )
 
@@ -357,7 +355,7 @@ class FilterEventsForClientTestCase(HomeserverTestCase):
         self.assertEqual(
             ["join", "join", "leave"],
             [
-                e.unsigned[EventUnsignedContentFields.MSC4115_MEMBERSHIP]
+                e.unsigned[EventUnsignedContentFields.MEMBERSHIP]
                 for e in joiner_filtered_events
             ],
         )
@@ -379,7 +377,7 @@ class FilterEventsForClientTestCase(HomeserverTestCase):
         self.assertEqual(
             ["join", "join", "join", "join", "join"],
             [
-                e.unsigned[EventUnsignedContentFields.MSC4115_MEMBERSHIP]
+                e.unsigned[EventUnsignedContentFields.MEMBERSHIP]
                 for e in resident_filtered_events
             ],
         )
@@ -441,7 +439,6 @@ class FilterEventsOutOfBandEventsForClientTestCase(
                 self.hs.get_storage_controllers(),
                 "@user:test",
                 [invite_event, reject_event],
-                msc4115_membership_on_events=True,
             )
         )
         self.assertEqual(
@@ -451,7 +448,7 @@ class FilterEventsOutOfBandEventsForClientTestCase(
         self.assertEqual(
             ["invite", "leave"],
             [
-                e.unsigned[EventUnsignedContentFields.MSC4115_MEMBERSHIP]
+                e.unsigned[EventUnsignedContentFields.MEMBERSHIP]
                 for e in filtered_events
             ],
         )
@@ -463,7 +460,6 @@ class FilterEventsOutOfBandEventsForClientTestCase(
                     self.hs.get_storage_controllers(),
                     "@other:test",
                     [invite_event, reject_event],
-                    msc4115_membership_on_events=True,
                 )
             ),
             [],