Add `room_types`/`not_room_types` filtering to Sliding Sync `/sync` (#17337)

Based on
[MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575):
Sliding Sync

3 files changed, 34 insertions, 6 deletions

diff --git a/synapse/handlers/sliding_sync.py b/synapse/handlers/sliding_sync.py
index 8622ef8472..0cebeea592 100644
--- a/synapse/handlers/sliding_sync.py
+++ b/synapse/handlers/sliding_sync.py
@@ -23,7 +23,13 @@ from typing import TYPE_CHECKING, Any, Dict, List, Optional, Set, Tuple
 import attr
 from immutabledict import immutabledict
 
-from synapse.api.constants import AccountDataTypes, Direction, EventTypes, Membership
+from synapse.api.constants import (
+    AccountDataTypes,
+    Direction,
+    EventContentFields,
+    EventTypes,
+    Membership,
+)
 from synapse.events import EventBase
 from synapse.events.utils import strip_event
 from synapse.handlers.relations import BundledAggregations
@@ -695,6 +701,10 @@ class SlidingSyncHandler:
                     state_filter=StateFilter.from_types(
                         [(EventTypes.RoomEncryption, "")]
                     ),
+                    # Partially stated rooms should have all state events except for the
+                    # membership events so we don't need to wait. Plus we don't want to
+                    # block the whole sync waiting for this one room.
+                    await_full_state=False,
                 )
                 is_encrypted = state_at_to_token.get((EventTypes.RoomEncryption, ""))
 
@@ -721,11 +731,26 @@ class SlidingSyncHandler:
                 ):
                     filtered_room_id_set.remove(room_id)
 
-        if filters.room_types:
-            raise NotImplementedError()
+        # Filter by room type (space vs room, etc). A room must match one of the types
+        # provided in the list. `None` is a valid type for rooms which do not have a
+        # room type.
+        if filters.room_types is not None or filters.not_room_types is not None:
+            # Make a copy so we don't run into an error: `Set changed size during
+            # iteration`, when we filter out and remove items
+            for room_id in list(filtered_room_id_set):
+                create_event = await self.store.get_create_event_for_room(room_id)
+                room_type = create_event.content.get(EventContentFields.ROOM_TYPE)
+                if (
+                    filters.room_types is not None
+                    and room_type not in filters.room_types
+                ):
+                    filtered_room_id_set.remove(room_id)
 
-        if filters.not_room_types:
-            raise NotImplementedError()
+                if (
+                    filters.not_room_types is not None
+                    and room_type in filters.not_room_types
+                ):
+                    filtered_room_id_set.remove(room_id)
 
         if filters.room_name_like:
             raise NotImplementedError()
diff --git a/synapse/storage/controllers/state.py b/synapse/storage/controllers/state.py
index cc9b162ae4..f3630fbbf1 100644
--- a/synapse/storage/controllers/state.py
+++ b/synapse/storage/controllers/state.py
@@ -436,6 +436,9 @@ class StateStorageController:
             )
         )
 
+        # FIXME: This will return incorrect results when there are timeline gaps. For
+        # example, when you try to get a point in the room we haven't backfilled before.
+
         if last_event_id:
             state = await self.get_state_after_event(
                 last_event_id,
diff --git a/synapse/types/rest/client/__init__.py b/synapse/types/rest/client/__init__.py
index 5d453769b5..55f6b44053 100644
--- a/synapse/types/rest/client/__init__.py
+++ b/synapse/types/rest/client/__init__.py
@@ -259,7 +259,7 @@ class SlidingSyncBody(RequestBodyModel):
             is_encrypted: Optional[StrictBool] = None
             is_invite: Optional[StrictBool] = None
             room_types: Optional[List[Union[StrictStr, None]]] = None
-            not_room_types: Optional[List[StrictStr]] = None
+            not_room_types: Optional[List[Union[StrictStr, None]]] = None
             room_name_like: Optional[StrictStr] = None
             tags: Optional[List[StrictStr]] = None
             not_tags: Optional[List[StrictStr]] = None