Add is_dm filtering to Sliding Sync /sync

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

changelog.d/17244.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.

synapse/handlers/sliding_sync.py

@@ -31,7 +31,7 @@ if TYPE_CHECKING or HAS_PYDANTIC_V2:
 else:
     from pydantic import Extra
 
-from synapse.api.constants import Membership
+from synapse.api.constants import AccountDataTypes, Membership
 from synapse.events import EventBase
 from synapse.rest.client.models import SlidingSyncBody
 from synapse.types import JsonMapping, Requester, RoomStreamToken, StreamToken, UserID
@@ -332,11 +332,15 @@ class SlidingSyncHandler:
         lists: Dict[str, SlidingSyncResult.SlidingWindowList] = {}
         if sync_config.lists:
             for list_key, list_config in sync_config.lists.items():
-                # TODO: Apply filters
+                # Apply filters
-                #
-                # TODO: Exclude partially stated rooms unless the `required_state` has
-                # `["m.room.member", "$LAZY"]`
                 filtered_room_ids = room_id_set
+                if list_config.filters is not None:
+                    # TODO: To be absolutely correct, this could also take into account
+                    # from/to tokens but some of the streams don't support looking back
+                    # in time (like global account_data).
+                    filtered_room_ids = await self.filter_rooms(
+                        sync_config.user, room_id_set, list_config.filters
+                    )
                 # TODO: Apply sorts
                 sorted_room_ids = sorted(filtered_room_ids)
 
@@ -608,3 +612,74 @@ 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,
+    ) -> AbstractSet[str]:
+        """
+        Filter rooms based on the sync request.
+        """
+        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.
+            dm_map = await self.store.get_global_account_data_by_type_for_user(
+                user_id, AccountDataTypes.DIRECT
+            )
+            logger.warn("dm_map: %s", dm_map)
+            # 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

tests/handlers/test_sliding_sync.py

@@ -22,7 +22,7 @@ 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.rest import admin
 from synapse.rest.client import knock, login, room
@@ -1116,3 +1116,157 @@ 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
+
+    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 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,
+        )
+
+        # TODO: Better way to avoid the circular import? (see
+        # https://github.com/element-hq/synapse/pull/17187#discussion_r1619492779)
+        from synapse.handlers.sliding_sync import SlidingSyncConfig
+
+        filters = SlidingSyncConfig.SlidingSyncList.Filters(
+            is_dm=True,
+        )
+
+        # Try filtering the rooms
+        filtered_room_ids = self.get_success(
+            self.sliding_sync_handler.filter_rooms(
+                UserID.from_string(user1_id), {room_id, dm_room_id}, filters
+            )
+        )
+
+        self.assertEqual(filtered_room_ids, {dm_room_id})
+
+    def test_filter_non_dm_rooms(self) -> None:
+        """
+        Test filter for non-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,
+        )
+
+        # TODO: Better way to avoid the circular import? (see
+        # https://github.com/element-hq/synapse/pull/17187#discussion_r1619492779)
+        from synapse.handlers.sliding_sync import SlidingSyncConfig
+
+        filters = SlidingSyncConfig.SlidingSyncList.Filters(
+            is_dm=False,
+        )
+
+        # Try filtering the rooms
+        filtered_room_ids = self.get_success(
+            self.sliding_sync_handler.filter_rooms(
+                UserID.from_string(user1_id), {room_id, dm_room_id}, filters
+            )
+        )
+
+        self.assertEqual(filtered_room_ids, {room_id})

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"]),
+        )