From f9caec5d9a9396f5388fcade48f494557731cb82 Mon Sep 17 00:00:00 2001
From: Brendan Abolivier <babolivier@matrix.org>
Date: Thu, 28 Jul 2022 13:03:00 +0200
Subject: [PATCH 1/9] Fix rooms not being properly excluded from incremental
 sync

---
 synapse/handlers/sync.py                     | 25 +++++++++++++-------
 synapse/storage/databases/main/events.py     |  8 ++++++-
 synapse/storage/databases/main/roommember.py | 19 +++++++++++----
 3 files changed, 37 insertions(+), 15 deletions(-)

diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index d42a414c9040..480b56a507c8 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -1536,14 +1536,16 @@ async def _generate_sync_entry_for_rooms(
         ignored_users = await self.store.ignored_users(user_id)
         if since_token:
             room_changes = await self._get_rooms_changed(
-                sync_result_builder, ignored_users, self.rooms_to_exclude
+                sync_result_builder,
+                ignored_users,
             )
             tags_by_room = await self.store.get_updated_tags(
                 user_id, since_token.account_data_key
             )
         else:
             room_changes = await self._get_all_rooms(
-                sync_result_builder, ignored_users, self.rooms_to_exclude
+                sync_result_builder,
+                ignored_users,
             )
             tags_by_room = await self.store.get_tags_for_user(user_id)
 
@@ -1623,13 +1625,14 @@ async def _get_rooms_changed(
         self,
         sync_result_builder: "SyncResultBuilder",
         ignored_users: FrozenSet[str],
-        excluded_rooms: List[str],
     ) -> _RoomChanges:
         """Determine the changes in rooms to report to the user.
 
         This function is a first pass at generating the rooms part of the sync response.
         It determines which rooms have changed during the sync period, and categorises
-        them into four buckets: "knock", "invite", "join" and "leave".
+        them into four buckets: "knock", "invite", "join" and "leave". It also excludes
+        from that list any room that appears in the list of rooms to exclude from sync
+        results in the server configuration.
 
         1. Finds all membership changes for the user in the sync period (from
            `since_token` up to `now_token`).
@@ -1655,7 +1658,7 @@ async def _get_rooms_changed(
         #       _have_rooms_changed. We could keep the results in memory to avoid a
         #       second query, at the cost of more complicated source code.
         membership_change_events = await self.store.get_membership_changes_for_user(
-            user_id, since_token.room_key, now_token.room_key, excluded_rooms
+            user_id, since_token.room_key, now_token.room_key, self.rooms_to_exclude
         )
 
         mem_change_events_by_room_id: Dict[str, List[EventBase]] = {}
@@ -1862,7 +1865,6 @@ async def _get_all_rooms(
         self,
         sync_result_builder: "SyncResultBuilder",
         ignored_users: FrozenSet[str],
-        ignored_rooms: List[str],
     ) -> _RoomChanges:
         """Returns entries for all rooms for the user.
 
@@ -1884,7 +1886,7 @@ async def _get_all_rooms(
         room_list = await self.store.get_rooms_for_local_user_where_membership_is(
             user_id=user_id,
             membership_list=Membership.LIST,
-            excluded_rooms=ignored_rooms,
+            excluded_rooms=self.rooms_to_exclude,
         )
 
         room_entries = []
@@ -2150,7 +2152,9 @@ async def _generate_room_entry(
                 raise Exception("Unrecognized rtype: %r", room_builder.rtype)
 
     async def get_rooms_for_user_at(
-        self, user_id: str, room_key: RoomStreamToken
+        self,
+        user_id: str,
+        room_key: RoomStreamToken,
     ) -> FrozenSet[str]:
         """Get set of joined rooms for a user at the given stream ordering.
 
@@ -2165,7 +2169,10 @@ async def get_rooms_for_user_at(
         ReturnValue:
             Set of room_ids the user is in at given stream_ordering.
         """
-        joined_rooms = await self.store.get_rooms_for_user_with_stream_ordering(user_id)
+        joined_rooms = await self.store.get_rooms_for_user_with_stream_ordering(
+            user_id,
+            exclude_for_sync=True,
+        )
 
         joined_room_ids = set()
 
diff --git a/synapse/storage/databases/main/events.py b/synapse/storage/databases/main/events.py
index 1f600f119029..9bd226a6924e 100644
--- a/synapse/storage/databases/main/events.py
+++ b/synapse/storage/databases/main/events.py
@@ -1172,9 +1172,15 @@ def _update_current_state_txn(
             # Invalidate the various caches
 
             for member in members_changed:
+                # We need to invalidate the cache for get_rooms_for_user_with_stream_ordering
+                # both with and without excluding rooms for sync results.
                 txn.call_after(
                     self.store.get_rooms_for_user_with_stream_ordering.invalidate,
-                    (member,),
+                    (member, False),
+                )
+                txn.call_after(
+                    self.store.get_rooms_for_user_with_stream_ordering.invalidate,
+                    (member, True),
                 )
 
             self.store._invalidate_state_caches_and_stream(
diff --git a/synapse/storage/databases/main/roommember.py b/synapse/storage/databases/main/roommember.py
index e2cccc688c9f..d0b4a595a6c0 100644
--- a/synapse/storage/databases/main/roommember.py
+++ b/synapse/storage/databases/main/roommember.py
@@ -121,6 +121,8 @@ def __init__(
                 lambda: self._known_servers_count,
             )
 
+        self._rooms_excluded_from_sync = hs.config.server.rooms_to_exclude_from_sync
+
     @wrap_as_background_process("_count_known_servers")
     async def _count_known_servers(self) -> int:
         """
@@ -565,7 +567,9 @@ async def get_local_current_membership_for_user_in_room(
 
     @cached(max_entries=500000, iterable=True)
     async def get_rooms_for_user_with_stream_ordering(
-        self, user_id: str
+        self,
+        user_id: str,
+        exclude_for_sync: bool = False,
     ) -> FrozenSet[GetRoomsForUserWithStreamOrdering]:
         """Returns a set of room_ids the user is currently joined to.
 
@@ -574,6 +578,8 @@ async def get_rooms_for_user_with_stream_ordering(
 
         Args:
             user_id
+            exclude_for_sync: Whether to exclude rooms that the configuration says
+                should be excluded from sync results.
 
         Returns:
             Returns the rooms the user is in currently, along with the stream
@@ -584,10 +590,11 @@ async def get_rooms_for_user_with_stream_ordering(
             "get_rooms_for_user_with_stream_ordering",
             self._get_rooms_for_user_with_stream_ordering_txn,
             user_id,
+            exclude_for_sync,
         )
 
     def _get_rooms_for_user_with_stream_ordering_txn(
-        self, txn: LoggingTransaction, user_id: str
+        self, txn: LoggingTransaction, user_id: str, exclude_for_sync: bool
     ) -> FrozenSet[GetRoomsForUserWithStreamOrdering]:
         # We use `current_state_events` here and not `local_current_membership`
         # as a) this gets called with remote users and b) this only gets called
@@ -620,6 +627,10 @@ def _get_rooms_for_user_with_stream_ordering_txn(
                 room_id, PersistedEventPosition(instance, stream_id)
             )
             for room_id, instance, stream_id in txn
+            if (
+                exclude_for_sync is False
+                or room_id not in self._rooms_excluded_from_sync
+            )
         )
 
     @cachedList(
@@ -729,9 +740,7 @@ async def get_rooms_for_user(
         If a remote user only returns rooms this server is currently
         participating in.
         """
-        rooms = await self.get_rooms_for_user_with_stream_ordering(
-            user_id, on_invalidate=on_invalidate
-        )
+        rooms = await self.get_rooms_for_user_with_stream_ordering(user_id)
         return frozenset(r.room_id for r in rooms)
 
     @cached(max_entries=10000)

From 8758612689717c66a5026d8349bd58929bb33a4d Mon Sep 17 00:00:00 2001
From: Brendan Abolivier <babolivier@matrix.org>
Date: Thu, 28 Jul 2022 13:09:11 +0200
Subject: [PATCH 2/9] Add test

---
 tests/rest/client/test_sync.py | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/tests/rest/client/test_sync.py b/tests/rest/client/test_sync.py
index b085c50356aa..ae161848281c 100644
--- a/tests/rest/client/test_sync.py
+++ b/tests/rest/client/test_sync.py
@@ -948,3 +948,24 @@ def test_invite(self) -> None:
 
         self.assertNotIn(self.excluded_room_id, channel.json_body["rooms"]["invite"])
         self.assertIn(self.included_room_id, channel.json_body["rooms"]["invite"])
+
+    def test_incremental_sync(self) -> None:
+        """Tests that activity in the room is properly filtered out of incremental
+        syncs.
+        """
+        channel = self.make_request("GET", "/sync", access_token=self.tok)
+        self.assertEqual(channel.code, 200, channel.result)
+        next_batch = channel.json_body["next_batch"]
+
+        self.helper.send(self.excluded_room_id, tok=self.tok)
+        self.helper.send(self.included_room_id, tok=self.tok)
+
+        channel = self.make_request(
+            "GET",
+            f"/sync?since={next_batch}",
+            access_token=self.tok,
+        )
+        self.assertEqual(channel.code, 200, channel.result)
+
+        self.assertNotIn(self.excluded_room_id, channel.json_body["rooms"]["join"])
+        self.assertIn(self.included_room_id, channel.json_body["rooms"]["join"])

From 50662685a4539316218c5829a62292b5203f1085 Mon Sep 17 00:00:00 2001
From: Brendan Abolivier <babolivier@matrix.org>
Date: Thu, 28 Jul 2022 13:19:43 +0200
Subject: [PATCH 3/9] Changelog

---
 changelog.d/13408.bugfix | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changelog.d/13408.bugfix

diff --git a/changelog.d/13408.bugfix b/changelog.d/13408.bugfix
new file mode 100644
index 000000000000..8b87b2cf7be5
--- /dev/null
+++ b/changelog.d/13408.bugfix
@@ -0,0 +1 @@
+Fix a bug introduced in Synapse 1.57.0 where rooms listed in `exclude_rooms_from_sync` in the configuration file would not be properly excluded from incremental syncs.

From 84dd001e094e3149202e21246fa042ff2f177427 Mon Sep 17 00:00:00 2001
From: Brendan Abolivier <babolivier@matrix.org>
Date: Thu, 28 Jul 2022 13:26:11 +0200
Subject: [PATCH 4/9] Formatting woes

---
 synapse/handlers/sync.py | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index 480b56a507c8..009f01d39c44 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -1536,17 +1536,13 @@ async def _generate_sync_entry_for_rooms(
         ignored_users = await self.store.ignored_users(user_id)
         if since_token:
             room_changes = await self._get_rooms_changed(
-                sync_result_builder,
-                ignored_users,
+                sync_result_builder, ignored_users
             )
             tags_by_room = await self.store.get_updated_tags(
                 user_id, since_token.account_data_key
             )
         else:
-            room_changes = await self._get_all_rooms(
-                sync_result_builder,
-                ignored_users,
-            )
+            room_changes = await self._get_all_rooms(sync_result_builder, ignored_users)
             tags_by_room = await self.store.get_tags_for_user(user_id)
 
         log_kv({"rooms_changed": len(room_changes.room_entries)})

From c6cc614caf0505360f8d0da10b6658fb588ba819 Mon Sep 17 00:00:00 2001
From: Brendan Abolivier <babolivier@matrix.org>
Date: Fri, 29 Jul 2022 10:48:24 +0200
Subject: [PATCH 5/9] Re-add invalidate pass-through, not sure how that went
 away

---
 synapse/storage/databases/main/roommember.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/synapse/storage/databases/main/roommember.py b/synapse/storage/databases/main/roommember.py
index d0b4a595a6c0..912b4f61e46d 100644
--- a/synapse/storage/databases/main/roommember.py
+++ b/synapse/storage/databases/main/roommember.py
@@ -740,7 +740,9 @@ async def get_rooms_for_user(
         If a remote user only returns rooms this server is currently
         participating in.
         """
-        rooms = await self.get_rooms_for_user_with_stream_ordering(user_id)
+        rooms = await self.get_rooms_for_user_with_stream_ordering(
+            user_id, on_invalidate=on_invalidate
+        )
         return frozenset(r.room_id for r in rooms)
 
     @cached(max_entries=10000)

From 77633ab7e974ad4d76d289031b8dfd0e8912129c Mon Sep 17 00:00:00 2001
From: Brendan Abolivier <babolivier@matrix.org>
Date: Fri, 29 Jul 2022 10:50:15 +0200
Subject: [PATCH 6/9] Correctly invalidate cache on replication

---
 synapse/storage/databases/main/cache.py | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/synapse/storage/databases/main/cache.py b/synapse/storage/databases/main/cache.py
index 12e9a423826a..3004150c17dd 100644
--- a/synapse/storage/databases/main/cache.py
+++ b/synapse/storage/databases/main/cache.py
@@ -202,8 +202,13 @@ def _process_event_stream_row(self, token: int, row: EventsStreamRow) -> None:
             self._curr_state_delta_stream_cache.entity_has_changed(data.room_id, token)
 
             if data.type == EventTypes.Member:
+                # We need to invalidate the cache for get_rooms_for_user_with_stream_ordering
+                # both with and without excluding rooms for sync results.
                 self.get_rooms_for_user_with_stream_ordering.invalidate(
-                    (data.state_key,)
+                    (data.state_key, False)
+                )
+                self.get_rooms_for_user_with_stream_ordering.invalidate(
+                    (data.state_key, True)
                 )
         else:
             raise Exception("Unknown events stream row type %s" % (row.type,))

From 8243b886226625b46b1493c6a0f5a042bf7b4a12 Mon Sep 17 00:00:00 2001
From: Brendan Abolivier <babolivier@matrix.org>
Date: Mon, 1 Aug 2022 17:31:25 +0200
Subject: [PATCH 7/9] Implement Erik's suggestion

---
 synapse/handlers/sync.py                     | 24 ++++++++++++++++----
 synapse/storage/databases/main/cache.py      |  7 +-----
 synapse/storage/databases/main/events.py     |  8 +------
 synapse/storage/databases/main/roommember.py | 12 +++-------
 4 files changed, 24 insertions(+), 27 deletions(-)

diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index 009f01d39c44..ec9e10e1fed3 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -28,7 +28,7 @@
 from synapse.logging.opentracing import SynapseTags, log_kv, set_tag, start_active_span
 from synapse.push.clientformat import format_push_rules_for_user
 from synapse.storage.databases.main.event_push_actions import NotifCounts
-from synapse.storage.roommember import MemberSummary
+from synapse.storage.roommember import GetRoomsForUserWithStreamOrdering, MemberSummary
 from synapse.storage.state import StateFilter
 from synapse.types import (
     DeviceListUpdates,
@@ -42,6 +42,7 @@
     UserID,
 )
 from synapse.util.async_helpers import concurrently_execute
+from synapse.util.caches.descriptors import _CacheContext, cached
 from synapse.util.caches.expiringcache import ExpiringCache
 from synapse.util.caches.lrucache import LruCache
 from synapse.util.caches.response_cache import ResponseCache, ResponseCacheContext
@@ -2165,10 +2166,7 @@ async def get_rooms_for_user_at(
         ReturnValue:
             Set of room_ids the user is in at given stream_ordering.
         """
-        joined_rooms = await self.store.get_rooms_for_user_with_stream_ordering(
-            user_id,
-            exclude_for_sync=True,
-        )
+        joined_rooms = await self._get_filtered_joined_rooms(user_id)
 
         joined_room_ids = set()
 
@@ -2199,6 +2197,22 @@ async def get_rooms_for_user_at(
 
         return frozenset(joined_room_ids)
 
+    @cached(cache_context=True, iterable=True)
+    async def _get_filtered_joined_rooms(
+        self, user_id: str, cache_context: _CacheContext
+    ) -> FrozenSet[GetRoomsForUserWithStreamOrdering]:
+        joined_rooms = await self.store.get_rooms_for_user_with_stream_ordering(
+            user_id,
+            on_invalidate=cache_context.invalidate,
+        )
+
+        if len(self.rooms_to_exclude) == 0:
+            return joined_rooms
+
+        return frozenset(
+            r for r in joined_rooms if r.room_id not in self.rooms_to_exclude
+        )
+
 
 def _action_has_highlight(actions: List[JsonDict]) -> bool:
     for action in actions:
diff --git a/synapse/storage/databases/main/cache.py b/synapse/storage/databases/main/cache.py
index 3004150c17dd..12e9a423826a 100644
--- a/synapse/storage/databases/main/cache.py
+++ b/synapse/storage/databases/main/cache.py
@@ -202,13 +202,8 @@ def _process_event_stream_row(self, token: int, row: EventsStreamRow) -> None:
             self._curr_state_delta_stream_cache.entity_has_changed(data.room_id, token)
 
             if data.type == EventTypes.Member:
-                # We need to invalidate the cache for get_rooms_for_user_with_stream_ordering
-                # both with and without excluding rooms for sync results.
                 self.get_rooms_for_user_with_stream_ordering.invalidate(
-                    (data.state_key, False)
-                )
-                self.get_rooms_for_user_with_stream_ordering.invalidate(
-                    (data.state_key, True)
+                    (data.state_key,)
                 )
         else:
             raise Exception("Unknown events stream row type %s" % (row.type,))
diff --git a/synapse/storage/databases/main/events.py b/synapse/storage/databases/main/events.py
index 9bd226a6924e..1f600f119029 100644
--- a/synapse/storage/databases/main/events.py
+++ b/synapse/storage/databases/main/events.py
@@ -1172,15 +1172,9 @@ def _update_current_state_txn(
             # Invalidate the various caches
 
             for member in members_changed:
-                # We need to invalidate the cache for get_rooms_for_user_with_stream_ordering
-                # both with and without excluding rooms for sync results.
                 txn.call_after(
                     self.store.get_rooms_for_user_with_stream_ordering.invalidate,
-                    (member, False),
-                )
-                txn.call_after(
-                    self.store.get_rooms_for_user_with_stream_ordering.invalidate,
-                    (member, True),
+                    (member,),
                 )
 
             self.store._invalidate_state_caches_and_stream(
diff --git a/synapse/storage/databases/main/roommember.py b/synapse/storage/databases/main/roommember.py
index 912b4f61e46d..a08d226feb55 100644
--- a/synapse/storage/databases/main/roommember.py
+++ b/synapse/storage/databases/main/roommember.py
@@ -121,8 +121,6 @@ def __init__(
                 lambda: self._known_servers_count,
             )
 
-        self._rooms_excluded_from_sync = hs.config.server.rooms_to_exclude_from_sync
-
     @wrap_as_background_process("_count_known_servers")
     async def _count_known_servers(self) -> int:
         """
@@ -569,7 +567,6 @@ async def get_local_current_membership_for_user_in_room(
     async def get_rooms_for_user_with_stream_ordering(
         self,
         user_id: str,
-        exclude_for_sync: bool = False,
     ) -> FrozenSet[GetRoomsForUserWithStreamOrdering]:
         """Returns a set of room_ids the user is currently joined to.
 
@@ -590,11 +587,12 @@ async def get_rooms_for_user_with_stream_ordering(
             "get_rooms_for_user_with_stream_ordering",
             self._get_rooms_for_user_with_stream_ordering_txn,
             user_id,
-            exclude_for_sync,
         )
 
     def _get_rooms_for_user_with_stream_ordering_txn(
-        self, txn: LoggingTransaction, user_id: str, exclude_for_sync: bool
+        self,
+        txn: LoggingTransaction,
+        user_id: str,
     ) -> FrozenSet[GetRoomsForUserWithStreamOrdering]:
         # We use `current_state_events` here and not `local_current_membership`
         # as a) this gets called with remote users and b) this only gets called
@@ -627,10 +625,6 @@ def _get_rooms_for_user_with_stream_ordering_txn(
                 room_id, PersistedEventPosition(instance, stream_id)
             )
             for room_id, instance, stream_id in txn
-            if (
-                exclude_for_sync is False
-                or room_id not in self._rooms_excluded_from_sync
-            )
         )
 
     @cachedList(

From f05b984b52993ff96964b1856215f90890c1c775 Mon Sep 17 00:00:00 2001
From: Brendan Abolivier <babolivier@matrix.org>
Date: Mon, 1 Aug 2022 17:33:12 +0200
Subject: [PATCH 8/9] Cleanup

---
 synapse/storage/databases/main/roommember.py | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/synapse/storage/databases/main/roommember.py b/synapse/storage/databases/main/roommember.py
index a08d226feb55..e2cccc688c9f 100644
--- a/synapse/storage/databases/main/roommember.py
+++ b/synapse/storage/databases/main/roommember.py
@@ -565,8 +565,7 @@ async def get_local_current_membership_for_user_in_room(
 
     @cached(max_entries=500000, iterable=True)
     async def get_rooms_for_user_with_stream_ordering(
-        self,
-        user_id: str,
+        self, user_id: str
     ) -> FrozenSet[GetRoomsForUserWithStreamOrdering]:
         """Returns a set of room_ids the user is currently joined to.
 
@@ -575,8 +574,6 @@ async def get_rooms_for_user_with_stream_ordering(
 
         Args:
             user_id
-            exclude_for_sync: Whether to exclude rooms that the configuration says
-                should be excluded from sync results.
 
         Returns:
             Returns the rooms the user is in currently, along with the stream
@@ -590,9 +587,7 @@ async def get_rooms_for_user_with_stream_ordering(
         )
 
     def _get_rooms_for_user_with_stream_ordering_txn(
-        self,
-        txn: LoggingTransaction,
-        user_id: str,
+        self, txn: LoggingTransaction, user_id: str
     ) -> FrozenSet[GetRoomsForUserWithStreamOrdering]:
         # We use `current_state_events` here and not `local_current_membership`
         # as a) this gets called with remote users and b) this only gets called

From e78f7bd14107d24d384a02899e148771587ddb7d Mon Sep 17 00:00:00 2001
From: Brendan Abolivier <babolivier@matrix.org>
Date: Tue, 2 Aug 2022 12:24:45 +0200
Subject: [PATCH 9/9] Incorporate suggestion

---
 synapse/handlers/sync.py | 26 +++++++-------------------
 1 file changed, 7 insertions(+), 19 deletions(-)

diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index ec9e10e1fed3..d827c03ad187 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -28,7 +28,7 @@
 from synapse.logging.opentracing import SynapseTags, log_kv, set_tag, start_active_span
 from synapse.push.clientformat import format_push_rules_for_user
 from synapse.storage.databases.main.event_push_actions import NotifCounts
-from synapse.storage.roommember import GetRoomsForUserWithStreamOrdering, MemberSummary
+from synapse.storage.roommember import MemberSummary
 from synapse.storage.state import StateFilter
 from synapse.types import (
     DeviceListUpdates,
@@ -42,7 +42,6 @@
     UserID,
 )
 from synapse.util.async_helpers import concurrently_execute
-from synapse.util.caches.descriptors import _CacheContext, cached
 from synapse.util.caches.expiringcache import ExpiringCache
 from synapse.util.caches.lrucache import LruCache
 from synapse.util.caches.response_cache import ResponseCache, ResponseCacheContext
@@ -2166,7 +2165,7 @@ async def get_rooms_for_user_at(
         ReturnValue:
             Set of room_ids the user is in at given stream_ordering.
         """
-        joined_rooms = await self._get_filtered_joined_rooms(user_id)
+        joined_rooms = await self.store.get_rooms_for_user_with_stream_ordering(user_id)
 
         joined_room_ids = set()
 
@@ -2177,7 +2176,12 @@ async def get_rooms_for_user_at(
         # If the membership's stream ordering is after the given stream
         # ordering, we need to go and work out if the user was in the room
         # before.
+        # We also need to check whether the room should be excluded from sync
+        # responses as per the homeserver config.
         for joined_room in joined_rooms:
+            if joined_room.room_id in self.rooms_to_exclude:
+                continue
+
             if not joined_room.event_pos.persisted_after(room_key):
                 joined_room_ids.add(joined_room.room_id)
                 continue
@@ -2197,22 +2201,6 @@ async def get_rooms_for_user_at(
 
         return frozenset(joined_room_ids)
 
-    @cached(cache_context=True, iterable=True)
-    async def _get_filtered_joined_rooms(
-        self, user_id: str, cache_context: _CacheContext
-    ) -> FrozenSet[GetRoomsForUserWithStreamOrdering]:
-        joined_rooms = await self.store.get_rooms_for_user_with_stream_ordering(
-            user_id,
-            on_invalidate=cache_context.invalidate,
-        )
-
-        if len(self.rooms_to_exclude) == 0:
-            return joined_rooms
-
-        return frozenset(
-            r for r in joined_rooms if r.room_id not in self.rooms_to_exclude
-        )
-
 
 def _action_has_highlight(actions: List[JsonDict]) -> bool:
     for action in actions: