Avoid fetching unused account data in sync. (#14973)

The per-room account data is no longer unconditionally
fetched, even if all rooms will be filtered out.

Global account data will not be fetched if it will all be
filtered out.

changelog.d/14973.misc

@@ -0,0 +1 @@
+Improve performance of `/sync` in a few situations.

synapse/api/filtering.py

@@ -219,9 +219,13 @@ def __init__(self, hs: "HomeServer", filter_json: JsonDict):
         self._room_timeline_filter = Filter(hs, room_filter_json.get("timeline", {}))
         self._room_state_filter = Filter(hs, room_filter_json.get("state", {}))
         self._room_ephemeral_filter = Filter(hs, room_filter_json.get("ephemeral", {}))
-        self._room_account_data = Filter(hs, room_filter_json.get("account_data", {}))
+        self._room_account_data_filter = Filter(
+            hs, room_filter_json.get("account_data", {})
+        )
         self._presence_filter = Filter(hs, filter_json.get("presence", {}))
-        self._account_data = Filter(hs, filter_json.get("account_data", {}))
+        self._global_account_data_filter = Filter(
+            hs, filter_json.get("account_data", {})
+        )
 
         self.include_leave = filter_json.get("room", {}).get("include_leave", False)
         self.event_fields = filter_json.get("event_fields", [])
@@ -256,8 +260,10 @@ async def filter_presence(
     ) -> List[UserPresenceState]:
         return await self._presence_filter.filter(presence_states)
 
-    async def filter_account_data(self, events: Iterable[JsonDict]) -> List[JsonDict]:
-        return await self._account_data.filter(events)
+    async def filter_global_account_data(
+        self, events: Iterable[JsonDict]
+    ) -> List[JsonDict]:
+        return await self._global_account_data_filter.filter(events)
 
     async def filter_room_state(self, events: Iterable[EventBase]) -> List[EventBase]:
         return await self._room_state_filter.filter(
@@ -279,7 +285,7 @@ async def filter_room_ephemeral(self, events: Iterable[JsonDict]) -> List[JsonDi
     async def filter_room_account_data(
         self, events: Iterable[JsonDict]
     ) -> List[JsonDict]:
-        return await self._room_account_data.filter(
+        return await self._room_account_data_filter.filter(
             await self._room_filter.filter(events)
         )
 
@@ -292,13 +298,27 @@ def blocks_all_presence(self) -> bool:
             or self._presence_filter.filters_all_senders()
         )
 
+    def blocks_all_global_account_data(self) -> bool:
+        """True if all global acount data will be filtered out."""
+        return (
+            self._global_account_data_filter.filters_all_types()
+            or self._global_account_data_filter.filters_all_senders()
+        )
+
     def blocks_all_room_ephemeral(self) -> bool:
         return (
             self._room_ephemeral_filter.filters_all_types()
             or self._room_ephemeral_filter.filters_all_senders()
             or self._room_ephemeral_filter.filters_all_rooms()
         )
 
+    def blocks_all_room_account_data(self) -> bool:
+        return (
+            self._room_account_data_filter.filters_all_types()
+            or self._room_account_data_filter.filters_all_senders()
+            or self._room_account_data_filter.filters_all_rooms()
+        )
+
     def blocks_all_room_timeline(self) -> bool:
         return (
             self._room_timeline_filter.filters_all_types()

synapse/handlers/account_data.py

@@ -343,10 +343,12 @@ async def get_new_events(
                 }
             )
 
-        (
-            account_data,
-            room_account_data,
-        ) = await self.store.get_updated_account_data_for_user(user_id, last_stream_id)
+        account_data = await self.store.get_updated_global_account_data_for_user(
+            user_id, last_stream_id
+        )
+        room_account_data = await self.store.get_updated_room_account_data_for_user(
+            user_id, last_stream_id
+        )
 
         for account_data_type, content in account_data.items():
             results.append({"type": account_data_type, "content": content})

synapse/handlers/initial_sync.py

@@ -154,9 +154,8 @@ async def _snapshot_all_rooms(
 
         tags_by_room = await self.store.get_tags_for_user(user_id)
 
-        account_data, account_data_by_room = await self.store.get_account_data_for_user(
-            user_id
-        )
+        account_data = await self.store.get_global_account_data_for_user(user_id)
+        account_data_by_room = await self.store.get_room_account_data_for_user(user_id)
 
         public_room_ids = await self.store.get_public_room_ids()
 

synapse/handlers/room_member.py

@@ -484,7 +484,7 @@ async def copy_room_tags_and_direct_to_room(
             user_id: The user's ID.
         """
         # Retrieve user account data for predecessor room
-        user_account_data, _ = await self.store.get_account_data_for_user(user_id)
+        user_account_data = await self.store.get_global_account_data_for_user(user_id)
 
         # Copy direct message state if applicable
         direct_rooms = user_account_data.get(AccountDataTypes.DIRECT, {})

synapse/handlers/sync.py

@@ -1444,9 +1444,9 @@ async def generate_sync_result(
 
         logger.debug("Fetching account data")
 
-        account_data_by_room = await self._generate_sync_entry_for_account_data(
-            sync_result_builder
-        )
+        # Global account data is included if it is not filtered out.
+        if not sync_config.filter_collection.blocks_all_global_account_data():
+            await self._generate_sync_entry_for_account_data(sync_result_builder)
 
         # Presence data is included if the server has it enabled and not filtered out.
         include_presence_data = bool(
@@ -1472,9 +1472,7 @@ async def generate_sync_result(
             (
                 newly_joined_rooms,
                 newly_left_rooms,
-            ) = await self._generate_sync_entry_for_rooms(
-                sync_result_builder, account_data_by_room
-            )
+            ) = await self._generate_sync_entry_for_rooms(sync_result_builder)
 
             # Work out which users have joined or left rooms we're in. We use this
             # to build the presence and device_list parts of the sync response in
@@ -1717,35 +1715,29 @@ async def _generate_sync_entry_for_to_device(
 
     async def _generate_sync_entry_for_account_data(
         self, sync_result_builder: "SyncResultBuilder"
-    ) -> Dict[str, Dict[str, JsonDict]]:
-        """Generates the account data portion of the sync response.
+    ) -> None:
+        """Generates the global account data portion of the sync response.
 
         Account data (called "Client Config" in the spec) can be set either globally
         or for a specific room. Account data consists of a list of events which
         accumulate state, much like a room.
 
-        This function retrieves global and per-room account data. The former is written
-        to the given `sync_result_builder`. The latter is returned directly, to be
-        later written to the `sync_result_builder` on a room-by-room basis.
+        This function retrieves global account data and writes it to the given
+        `sync_result_builder`. See `_generate_sync_entry_for_rooms` for handling
+         of per-room account data.
 
         Args:
             sync_result_builder
-
-        Returns:
-            A dictionary whose keys (room ids) map to the per room account data for that
-            room.
         """
         sync_config = sync_result_builder.sync_config
         user_id = sync_result_builder.sync_config.user.to_string()
         since_token = sync_result_builder.since_token
 
         if since_token and not sync_result_builder.full_state:
-            # TODO Do not fetch room account data if it will be unused.
-            (
-                global_account_data,
-                account_data_by_room,
-            ) = await self.store.get_updated_account_data_for_user(
-                user_id, since_token.account_data_key
+            global_account_data = (
+                await self.store.get_updated_global_account_data_for_user(
+                    user_id, since_token.account_data_key
+                )
             )
 
             push_rules_changed = await self.store.have_push_rules_changed_for_user(
@@ -1758,28 +1750,26 @@ async def _generate_sync_entry_for_account_data(
                     sync_config.user
                 )
         else:
-            # TODO Do not fetch room account data if it will be unused.
-            (
-                global_account_data,
-                account_data_by_room,
-            ) = await self.store.get_account_data_for_user(sync_config.user.to_string())
+            all_global_account_data = await self.store.get_global_account_data_for_user(
+                user_id
+            )
 
-            global_account_data = dict(global_account_data)
+            global_account_data = dict(all_global_account_data)
             global_account_data["m.push_rules"] = await self.push_rules_for_user(
                 sync_config.user
             )
 
-        account_data_for_user = await sync_config.filter_collection.filter_account_data(
-            [
-                {"type": account_data_type, "content": content}
-                for account_data_type, content in global_account_data.items()
-            ]
+        account_data_for_user = (
+            await sync_config.filter_collection.filter_global_account_data(
+                [
+                    {"type": account_data_type, "content": content}
+                    for account_data_type, content in global_account_data.items()
+                ]
+            )
         )
 
         sync_result_builder.account_data = account_data_for_user
 
-        return account_data_by_room
-
     async def _generate_sync_entry_for_presence(
         self,
         sync_result_builder: "SyncResultBuilder",
@@ -1839,9 +1829,7 @@ async def _generate_sync_entry_for_presence(
         sync_result_builder.presence = presence
 
     async def _generate_sync_entry_for_rooms(
-        self,
-        sync_result_builder: "SyncResultBuilder",
-        account_data_by_room: Dict[str, Dict[str, JsonDict]],
+        self, sync_result_builder: "SyncResultBuilder"
     ) -> Tuple[AbstractSet[str], AbstractSet[str]]:
         """Generates the rooms portion of the sync response. Populates the
         `sync_result_builder` with the result.
@@ -1852,7 +1840,6 @@ async def _generate_sync_entry_for_rooms(
 
         Args:
             sync_result_builder
-            account_data_by_room: Dictionary of per room account data
 
         Returns:
             Returns a 2-tuple describing rooms the user has joined or left.
@@ -1865,9 +1852,30 @@ async def _generate_sync_entry_for_rooms(
         since_token = sync_result_builder.since_token
         user_id = sync_result_builder.sync_config.user.to_string()
 
+        blocks_all_rooms = (
+            sync_result_builder.sync_config.filter_collection.blocks_all_rooms()
+        )
+
+        # 0. Start by fetching room account data (if required).
+        if (
+            blocks_all_rooms
+            or sync_result_builder.sync_config.filter_collection.blocks_all_room_account_data()
+        ):
+            account_data_by_room: Mapping[str, Mapping[str, JsonDict]] = {}
+        elif since_token and not sync_result_builder.full_state:
+            account_data_by_room = (
+                await self.store.get_updated_room_account_data_for_user(
+                    user_id, since_token.account_data_key
+                )
+            )
+        else:
+            account_data_by_room = await self.store.get_room_account_data_for_user(
+                user_id
+            )
+
         # 1. Start by fetching all ephemeral events in rooms we've joined (if required).
         block_all_room_ephemeral = (
-            sync_result_builder.sync_config.filter_collection.blocks_all_rooms()
+            blocks_all_rooms
             or sync_result_builder.sync_config.filter_collection.blocks_all_room_ephemeral()
         )
         if block_all_room_ephemeral:
@@ -2294,7 +2302,7 @@ async def _generate_room_entry(
         room_builder: "RoomSyncResultBuilder",
         ephemeral: List[JsonDict],
         tags: Optional[Dict[str, Dict[str, Any]]],
-        account_data: Dict[str, JsonDict],
+        account_data: Mapping[str, JsonDict],
         always_include: bool = False,
     ) -> None:
         """Populates the `joined` and `archived` section of `sync_result_builder`

synapse/rest/admin/users.py

@@ -1192,7 +1192,8 @@ async def on_GET(
         if not await self._store.get_user_by_id(user_id):
             raise NotFoundError("User not found")
 
-        global_data, by_room_data = await self._store.get_account_data_for_user(user_id)
+        global_data = await self._store.get_global_account_data_for_user(user_id)
+        by_room_data = await self._store.get_room_account_data_for_user(user_id)
         return HTTPStatus.OK, {
             "account_data": {
                 "global": global_data,