Remove remaining pieces of groups code. (#12966)

* Remove an unused stream ID generator.
* Remove the now unused remote profile cache.

8 files changed, 6 insertions, 209 deletions

diff --git a/changelog.d/12966.removal b/changelog.d/12966.removal
new file mode 100644
index 0000000000..41f6fae5da
--- /dev/null
+++ b/changelog.d/12966.removal
@@ -0,0 +1 @@
+Remove support for the non-standard groups/communities feature from Synapse.
diff --git a/synapse/_scripts/synapse_port_db.py b/synapse/_scripts/synapse_port_db.py
index 4939573f30..361b51d2fa 100755
--- a/synapse/_scripts/synapse_port_db.py
+++ b/synapse/_scripts/synapse_port_db.py
@@ -182,6 +182,7 @@ IGNORED_TABLES = {
     "groups",
     "local_group_membership",
     "local_group_updates",
+    "remote_profile_cache",
 }
 
 
diff --git a/synapse/handlers/profile.py b/synapse/handlers/profile.py
index 239b0aa744..6eed3826a7 100644
--- a/synapse/handlers/profile.py
+++ b/synapse/handlers/profile.py
@@ -23,14 +23,7 @@ from synapse.api.errors import (
     StoreError,
     SynapseError,
 )
-from synapse.metrics.background_process_metrics import wrap_as_background_process
-from synapse.types import (
-    JsonDict,
-    Requester,
-    UserID,
-    create_requester,
-    get_domain_from_id,
-)
+from synapse.types import JsonDict, Requester, UserID, create_requester
 from synapse.util.caches.descriptors import cached
 from synapse.util.stringutils import parse_and_validate_mxc_uri
 
@@ -50,9 +43,6 @@ class ProfileHandler:
     delegate to master when necessary.
     """
 
-    PROFILE_UPDATE_MS = 60 * 1000
-    PROFILE_UPDATE_EVERY_MS = 24 * 60 * 60 * 1000
-
     def __init__(self, hs: "HomeServer"):
         self.store = hs.get_datastores().main
         self.clock = hs.get_clock()
@@ -73,11 +63,6 @@ class ProfileHandler:
 
         self._third_party_rules = hs.get_third_party_event_rules()
 
-        if hs.config.worker.run_background_tasks:
-            self.clock.looping_call(
-                self._update_remote_profile_cache, self.PROFILE_UPDATE_MS
-            )
-
     async def get_profile(self, user_id: str) -> JsonDict:
         target_user = UserID.from_string(user_id)
 
@@ -116,30 +101,6 @@ class ProfileHandler:
                     raise SynapseError(502, "Failed to fetch profile")
                 raise e.to_synapse_error()
 
-    async def get_profile_from_cache(self, user_id: str) -> JsonDict:
-        """Get the profile information from our local cache. If the user is
-        ours then the profile information will always be correct. Otherwise,
-        it may be out of date/missing.
-        """
-        target_user = UserID.from_string(user_id)
-        if self.hs.is_mine(target_user):
-            try:
-                displayname = await self.store.get_profile_displayname(
-                    target_user.localpart
-                )
-                avatar_url = await self.store.get_profile_avatar_url(
-                    target_user.localpart
-                )
-            except StoreError as e:
-                if e.code == 404:
-                    raise SynapseError(404, "Profile was not found", Codes.NOT_FOUND)
-                raise
-
-            return {"displayname": displayname, "avatar_url": avatar_url}
-        else:
-            profile = await self.store.get_from_remote_profile_cache(user_id)
-            return profile or {}
-
     async def get_displayname(self, target_user: UserID) -> Optional[str]:
         if self.hs.is_mine(target_user):
             try:
@@ -509,45 +470,3 @@ class ProfileHandler:
                 # so we act as if we couldn't find the profile.
                 raise SynapseError(403, "Profile isn't available", Codes.FORBIDDEN)
             raise
-
-    @wrap_as_background_process("Update remote profile")
-    async def _update_remote_profile_cache(self) -> None:
-        """Called periodically to check profiles of remote users we haven't
-        checked in a while.
-        """
-        entries = await self.store.get_remote_profile_cache_entries_that_expire(
-            last_checked=self.clock.time_msec() - self.PROFILE_UPDATE_EVERY_MS
-        )
-
-        for user_id, displayname, avatar_url in entries:
-            is_subscribed = await self.store.is_subscribed_remote_profile_for_user(
-                user_id
-            )
-            if not is_subscribed:
-                await self.store.maybe_delete_remote_profile_cache(user_id)
-                continue
-
-            try:
-                profile = await self.federation.make_query(
-                    destination=get_domain_from_id(user_id),
-                    query_type="profile",
-                    args={"user_id": user_id},
-                    ignore_backoff=True,
-                )
-            except Exception:
-                logger.exception("Failed to get avatar_url")
-
-                await self.store.update_remote_profile_cache(
-                    user_id, displayname, avatar_url
-                )
-                continue
-
-            new_name = profile.get("displayname")
-            if not isinstance(new_name, str):
-                new_name = None
-            new_avatar = profile.get("avatar_url")
-            if not isinstance(new_avatar, str):
-                new_avatar = None
-
-            # We always hit update to update the last_check timestamp
-            await self.store.update_remote_profile_cache(user_id, new_name, new_avatar)
diff --git a/synapse/storage/databases/main/__init__.py b/synapse/storage/databases/main/__init__.py
index d545a1c002..11d9d16c19 100644
--- a/synapse/storage/databases/main/__init__.py
+++ b/synapse/storage/databases/main/__init__.py
@@ -151,10 +151,6 @@ class DataStore(
             ],
         )
 
-        self._group_updates_id_gen = StreamIdGenerator(
-            db_conn, "local_group_updates", "stream_id"
-        )
-
         self._cache_id_gen: Optional[MultiWriterIdGenerator]
         if isinstance(self.database_engine, PostgresEngine):
             # We set the `writers` to an empty list here as we don't care about
@@ -197,20 +193,6 @@ class DataStore(
             prefilled_cache=curr_state_delta_prefill,
         )
 
-        _group_updates_prefill, min_group_updates_id = self.db_pool.get_cache_dict(
-            db_conn,
-            "local_group_updates",
-            entity_column="user_id",
-            stream_column="stream_id",
-            max_value=self._group_updates_id_gen.get_current_token(),
-            limit=1000,
-        )
-        self._group_updates_stream_cache = StreamChangeCache(
-            "_group_updates_stream_cache",
-            min_group_updates_id,
-            prefilled_cache=_group_updates_prefill,
-        )
-
         self._stream_order_on_start = self.get_room_max_stream_ordering()
         self._min_stream_order_on_start = self.get_room_min_stream_ordering()
 
diff --git a/synapse/storage/databases/main/profile.py b/synapse/storage/databases/main/profile.py
index e197b7203e..a1747f04ce 100644
--- a/synapse/storage/databases/main/profile.py
+++ b/synapse/storage/databases/main/profile.py
@@ -11,11 +11,10 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-from typing import Any, Dict, List, Optional
+from typing import Optional
 
 from synapse.api.errors import StoreError
 from synapse.storage._base import SQLBaseStore
-from synapse.storage.database import LoggingTransaction
 from synapse.storage.databases.main.roommember import ProfileInfo
 
 
@@ -55,17 +54,6 @@ class ProfileWorkerStore(SQLBaseStore):
             desc="get_profile_avatar_url",
         )
 
-    async def get_from_remote_profile_cache(
-        self, user_id: str
-    ) -> Optional[Dict[str, Any]]:
-        return await self.db_pool.simple_select_one(
-            table="remote_profile_cache",
-            keyvalues={"user_id": user_id},
-            retcols=("displayname", "avatar_url"),
-            allow_none=True,
-            desc="get_from_remote_profile_cache",
-        )
-
     async def create_profile(self, user_localpart: str) -> None:
         await self.db_pool.simple_insert(
             table="profiles", values={"user_id": user_localpart}, desc="create_profile"
@@ -91,97 +79,6 @@ class ProfileWorkerStore(SQLBaseStore):
             desc="set_profile_avatar_url",
         )
 
-    async def update_remote_profile_cache(
-        self, user_id: str, displayname: Optional[str], avatar_url: Optional[str]
-    ) -> int:
-        return await self.db_pool.simple_update(
-            table="remote_profile_cache",
-            keyvalues={"user_id": user_id},
-            updatevalues={
-                "displayname": displayname,
-                "avatar_url": avatar_url,
-                "last_check": self._clock.time_msec(),
-            },
-            desc="update_remote_profile_cache",
-        )
-
-    async def maybe_delete_remote_profile_cache(self, user_id: str) -> None:
-        """Check if we still care about the remote user's profile, and if we
-        don't then remove their profile from the cache
-        """
-        subscribed = await self.is_subscribed_remote_profile_for_user(user_id)
-        if not subscribed:
-            await self.db_pool.simple_delete(
-                table="remote_profile_cache",
-                keyvalues={"user_id": user_id},
-                desc="delete_remote_profile_cache",
-            )
-
-    async def is_subscribed_remote_profile_for_user(self, user_id: str) -> bool:
-        """Check whether we are interested in a remote user's profile."""
-        res: Optional[str] = await self.db_pool.simple_select_one_onecol(
-            table="group_users",
-            keyvalues={"user_id": user_id},
-            retcol="user_id",
-            allow_none=True,
-            desc="should_update_remote_profile_cache_for_user",
-        )
-
-        if res:
-            return True
-
-        res = await self.db_pool.simple_select_one_onecol(
-            table="group_invites",
-            keyvalues={"user_id": user_id},
-            retcol="user_id",
-            allow_none=True,
-            desc="should_update_remote_profile_cache_for_user",
-        )
-
-        if res:
-            return True
-        return False
-
-    async def get_remote_profile_cache_entries_that_expire(
-        self, last_checked: int
-    ) -> List[Dict[str, str]]:
-        """Get all users who haven't been checked since `last_checked`"""
-
-        def _get_remote_profile_cache_entries_that_expire_txn(
-            txn: LoggingTransaction,
-        ) -> List[Dict[str, str]]:
-            sql = """
-                SELECT user_id, displayname, avatar_url
-                FROM remote_profile_cache
-                WHERE last_check < ?
-            """
-
-            txn.execute(sql, (last_checked,))
-
-            return self.db_pool.cursor_to_dict(txn)
-
-        return await self.db_pool.runInteraction(
-            "get_remote_profile_cache_entries_that_expire",
-            _get_remote_profile_cache_entries_that_expire_txn,
-        )
-
 
 class ProfileStore(ProfileWorkerStore):
-    async def add_remote_profile_cache(
-        self, user_id: str, displayname: str, avatar_url: str
-    ) -> None:
-        """Ensure we are caching the remote user's profiles.
-
-        This should only be called when `is_subscribed_remote_profile_for_user`
-        would return true for the user.
-        """
-        await self.db_pool.simple_upsert(
-            table="remote_profile_cache",
-            keyvalues={"user_id": user_id},
-            values={
-                "displayname": displayname,
-                "avatar_url": avatar_url,
-                "last_check": self._clock.time_msec(),
-            },
-            desc="add_remote_profile_cache",
-        )
+    pass
diff --git a/synapse/storage/databases/main/purge_events.py b/synapse/storage/databases/main/purge_events.py
index 2353c120e9..ba385f9fc4 100644
--- a/synapse/storage/databases/main/purge_events.py
+++ b/synapse/storage/databases/main/purge_events.py
@@ -393,7 +393,6 @@ class PurgeEventsStore(StateGroupWorkerStore, CacheInvalidationWorkerStore):
             "partial_state_events",
             "events",
             "federation_inbound_events_staging",
-            "group_rooms",
             "local_current_membership",
             "partial_state_rooms_servers",
             "partial_state_rooms",
@@ -413,7 +412,6 @@ class PurgeEventsStore(StateGroupWorkerStore, CacheInvalidationWorkerStore):
             "e2e_room_keys",
             "event_push_summary",
             "pusher_throttle",
-            "group_summary_rooms",
             "room_account_data",
             "room_tags",
             # "rooms" happens last, to keep the foreign keys in the other tables
diff --git a/synapse/storage/schema/__init__.py b/synapse/storage/schema/__init__.py
index 19466150d4..5843fae605 100644
--- a/synapse/storage/schema/__init__.py
+++ b/synapse/storage/schema/__init__.py
@@ -70,6 +70,7 @@ Changes in SCHEMA_VERSION = 70:
 
 Changes in SCHEMA_VERSION = 71:
     - event_edges.room_id is no longer read from.
+    - Tables related to groups are no longer accessed.
 """
 
 
diff --git a/tests/rest/admin/test_room.py b/tests/rest/admin/test_room.py
index 608d3f2dc3..ca6af9417b 100644
--- a/tests/rest/admin/test_room.py
+++ b/tests/rest/admin/test_room.py
@@ -2467,7 +2467,6 @@ PURGE_TABLES = [
     "event_push_actions",
     "event_search",
     "events",
-    "group_rooms",
     "receipts_graph",
     "receipts_linearized",
     "room_aliases",
@@ -2484,7 +2483,6 @@ PURGE_TABLES = [
     "e2e_room_keys",
     "event_push_summary",
     "pusher_throttle",
-    "group_summary_rooms",
     "room_account_data",
     "room_tags",
     # "state_groups",  # Current impl leaves orphaned state groups around.