From da05b70af5bf84825332b2ac0d63c6deda4b376f Mon Sep 17 00:00:00 2001 From: Patrick Cloke Date: Thu, 2 Feb 2023 13:45:12 -0500 Subject: [PATCH] Skip unused calculations in sync handler. (#14908) If a sync request does not need to calculate per-room entries & is not generating presence & is not generating device list data (e.g. during initial sync) avoid the expensive calculation of room specific data. This is a micro-optimisation for clients syncing simply to receive to-device information. --- changelog.d/14908.misc | 1 + synapse/api/filtering.py | 3 + synapse/handlers/sync.py | 258 ++++++++++++++++++++------------------- 3 files changed, 137 insertions(+), 125 deletions(-) create mode 100644 changelog.d/14908.misc diff --git a/changelog.d/14908.misc b/changelog.d/14908.misc new file mode 100644 index 000000000000..365762360285 --- /dev/null +++ b/changelog.d/14908.misc @@ -0,0 +1 @@ +Improve performance of `/sync` in a few situations. diff --git a/synapse/api/filtering.py b/synapse/api/filtering.py index 4cf8f0cc8ef9..2b5af264b43d 100644 --- a/synapse/api/filtering.py +++ b/synapse/api/filtering.py @@ -283,6 +283,9 @@ async def filter_room_account_data( await self._room_filter.filter(events) ) + def blocks_all_rooms(self) -> bool: + return self._room_filter.filters_all_rooms() + def blocks_all_presence(self) -> bool: return ( self._presence_filter.filters_all_types() diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py index 0cb8d5ef4b66..3566537894e6 100644 --- a/synapse/handlers/sync.py +++ b/synapse/handlers/sync.py @@ -1448,41 +1448,67 @@ async def generate_sync_result( sync_result_builder ) - logger.debug("Fetching room data") - - ( - newly_joined_rooms, - newly_joined_or_invited_or_knocked_users, - newly_left_rooms, - newly_left_users, - ) = await self._generate_sync_entry_for_rooms( - sync_result_builder, account_data_by_room - ) - # Presence data is included if the server has it enabled and not filtered out. - include_presence_data = ( + include_presence_data = bool( self.hs_config.server.use_presence and not sync_config.filter_collection.blocks_all_presence() ) - if include_presence_data: - logger.debug("Fetching presence data") - await self._generate_sync_entry_for_presence( - sync_result_builder, + # Device list updates are sent if a since token is provided. + include_device_list_updates = bool(since_token and since_token.device_list_key) + + # If we do not care about the rooms or things which depend on the room + # data (namely presence and device list updates), then we can skip + # this process completely. + device_lists = DeviceListUpdates() + if ( + not sync_result_builder.sync_config.filter_collection.blocks_all_rooms() + or include_presence_data + or include_device_list_updates + ): + logger.debug("Fetching room data") + + # Note that _generate_sync_entry_for_rooms sets sync_result_builder.joined, which + # is used in calculate_user_changes below. + ( newly_joined_rooms, - newly_joined_or_invited_or_knocked_users, + newly_left_rooms, + ) = await self._generate_sync_entry_for_rooms( + sync_result_builder, account_data_by_room ) + # 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 + # `_generate_sync_entry_for_presence` and + # `_generate_sync_entry_for_device_list` respectively. + if include_presence_data or include_device_list_updates: + # This uses the sync_result_builder.joined which is set in + # `_generate_sync_entry_for_rooms`, if that didn't find any joined + # rooms for some reason it is a no-op. + ( + newly_joined_or_invited_or_knocked_users, + newly_left_users, + ) = sync_result_builder.calculate_user_changes() + + if include_presence_data: + logger.debug("Fetching presence data") + await self._generate_sync_entry_for_presence( + sync_result_builder, + newly_joined_rooms, + newly_joined_or_invited_or_knocked_users, + ) + + if include_device_list_updates: + device_lists = await self._generate_sync_entry_for_device_list( + sync_result_builder, + newly_joined_rooms=newly_joined_rooms, + newly_joined_or_invited_or_knocked_users=newly_joined_or_invited_or_knocked_users, + newly_left_rooms=newly_left_rooms, + newly_left_users=newly_left_users, + ) + logger.debug("Fetching to-device data") await self._generate_sync_entry_for_to_device(sync_result_builder) - device_lists = await self._generate_sync_entry_for_device_list( - sync_result_builder, - newly_joined_rooms=newly_joined_rooms, - newly_joined_or_invited_or_knocked_users=newly_joined_or_invited_or_knocked_users, - newly_left_rooms=newly_left_rooms, - newly_left_users=newly_left_users, - ) - logger.debug("Fetching OTK data") device_id = sync_config.device_id one_time_keys_count: JsonDict = {} @@ -1551,6 +1577,7 @@ async def _generate_sync_entry_for_device_list( user_id = sync_result_builder.sync_config.user.to_string() since_token = sync_result_builder.since_token + assert since_token is not None # Take a copy since these fields will be mutated later. newly_joined_or_invited_or_knocked_users = set( @@ -1558,92 +1585,85 @@ async def _generate_sync_entry_for_device_list( ) newly_left_users = set(newly_left_users) - if since_token and since_token.device_list_key: - # We want to figure out what user IDs the client should refetch - # device keys for, and which users we aren't going to track changes - # for anymore. - # - # For the first step we check: - # a. if any users we share a room with have updated their devices, - # and - # b. we also check if we've joined any new rooms, or if a user has - # joined a room we're in. - # - # For the second step we just find any users we no longer share a - # room with by looking at all users that have left a room plus users - # that were in a room we've left. + # We want to figure out what user IDs the client should refetch + # device keys for, and which users we aren't going to track changes + # for anymore. + # + # For the first step we check: + # a. if any users we share a room with have updated their devices, + # and + # b. we also check if we've joined any new rooms, or if a user has + # joined a room we're in. + # + # For the second step we just find any users we no longer share a + # room with by looking at all users that have left a room plus users + # that were in a room we've left. - users_that_have_changed = set() + users_that_have_changed = set() - joined_rooms = sync_result_builder.joined_room_ids + joined_rooms = sync_result_builder.joined_room_ids - # Step 1a, check for changes in devices of users we share a room - # with - # - # We do this in two different ways depending on what we have cached. - # If we already have a list of all the user that have changed since - # the last sync then it's likely more efficient to compare the rooms - # they're in with the rooms the syncing user is in. - # - # If we don't have that info cached then we get all the users that - # share a room with our user and check if those users have changed. - cache_result = self.store.get_cached_device_list_changes( - since_token.device_list_key - ) - if cache_result.hit: - changed_users = cache_result.entities - - result = await self.store.get_rooms_for_users(changed_users) - - for changed_user_id, entries in result.items(): - # Check if the changed user shares any rooms with the user, - # or if the changed user is the syncing user (as we always - # want to include device list updates of their own devices). - if user_id == changed_user_id or any( - rid in joined_rooms for rid in entries - ): - users_that_have_changed.add(changed_user_id) - else: - users_that_have_changed = ( - await self._device_handler.get_device_changes_in_shared_rooms( - user_id, - sync_result_builder.joined_room_ids, - from_token=since_token, - ) - ) - - # Step 1b, check for newly joined rooms - for room_id in newly_joined_rooms: - joined_users = await self.store.get_users_in_room(room_id) - newly_joined_or_invited_or_knocked_users.update(joined_users) + # Step 1a, check for changes in devices of users we share a room + # with + # + # We do this in two different ways depending on what we have cached. + # If we already have a list of all the user that have changed since + # the last sync then it's likely more efficient to compare the rooms + # they're in with the rooms the syncing user is in. + # + # If we don't have that info cached then we get all the users that + # share a room with our user and check if those users have changed. + cache_result = self.store.get_cached_device_list_changes( + since_token.device_list_key + ) + if cache_result.hit: + changed_users = cache_result.entities - # TODO: Check that these users are actually new, i.e. either they - # weren't in the previous sync *or* they left and rejoined. - users_that_have_changed.update(newly_joined_or_invited_or_knocked_users) + result = await self.store.get_rooms_for_users(changed_users) - user_signatures_changed = ( - await self.store.get_users_whose_signatures_changed( - user_id, since_token.device_list_key + for changed_user_id, entries in result.items(): + # Check if the changed user shares any rooms with the user, + # or if the changed user is the syncing user (as we always + # want to include device list updates of their own devices). + if user_id == changed_user_id or any( + rid in joined_rooms for rid in entries + ): + users_that_have_changed.add(changed_user_id) + else: + users_that_have_changed = ( + await self._device_handler.get_device_changes_in_shared_rooms( + user_id, + sync_result_builder.joined_room_ids, + from_token=since_token, ) ) - users_that_have_changed.update(user_signatures_changed) - # Now find users that we no longer track - for room_id in newly_left_rooms: - left_users = await self.store.get_users_in_room(room_id) - newly_left_users.update(left_users) + # Step 1b, check for newly joined rooms + for room_id in newly_joined_rooms: + joined_users = await self.store.get_users_in_room(room_id) + newly_joined_or_invited_or_knocked_users.update(joined_users) - # Remove any users that we still share a room with. - left_users_rooms = await self.store.get_rooms_for_users(newly_left_users) - for user_id, entries in left_users_rooms.items(): - if any(rid in joined_rooms for rid in entries): - newly_left_users.discard(user_id) + # TODO: Check that these users are actually new, i.e. either they + # weren't in the previous sync *or* they left and rejoined. + users_that_have_changed.update(newly_joined_or_invited_or_knocked_users) - return DeviceListUpdates( - changed=users_that_have_changed, left=newly_left_users - ) - else: - return DeviceListUpdates() + user_signatures_changed = await self.store.get_users_whose_signatures_changed( + user_id, since_token.device_list_key + ) + users_that_have_changed.update(user_signatures_changed) + + # Now find users that we no longer track + for room_id in newly_left_rooms: + left_users = await self.store.get_users_in_room(room_id) + newly_left_users.update(left_users) + + # Remove any users that we still share a room with. + left_users_rooms = await self.store.get_rooms_for_users(newly_left_users) + for user_id, entries in left_users_rooms.items(): + if any(rid in joined_rooms for rid in entries): + newly_left_users.discard(user_id) + + return DeviceListUpdates(changed=users_that_have_changed, left=newly_left_users) @trace async def _generate_sync_entry_for_to_device( @@ -1720,6 +1740,7 @@ async def _generate_sync_entry_for_account_data( 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, @@ -1736,6 +1757,7 @@ 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, @@ -1818,7 +1840,7 @@ async def _generate_sync_entry_for_rooms( self, sync_result_builder: "SyncResultBuilder", account_data_by_room: Dict[str, Dict[str, JsonDict]], - ) -> Tuple[AbstractSet[str], AbstractSet[str], AbstractSet[str], AbstractSet[str]]: + ) -> Tuple[AbstractSet[str], AbstractSet[str]]: """Generates the rooms portion of the sync response. Populates the `sync_result_builder` with the result. @@ -1831,24 +1853,22 @@ async def _generate_sync_entry_for_rooms( account_data_by_room: Dictionary of per room account data Returns: - Returns a 4-tuple describing rooms the user has joined or left, and users who've - joined or left rooms any rooms the user is in. This gets used later in - `_generate_sync_entry_for_device_list`. + Returns a 2-tuple describing rooms the user has joined or left. Its entries are: - newly_joined_rooms - - newly_joined_or_invited_or_knocked_users - newly_left_rooms - - newly_left_users """ since_token = sync_result_builder.since_token user_id = sync_result_builder.sync_config.user.to_string() # 1. Start by fetching all ephemeral events in rooms we've joined (if required). - if ( - sync_result_builder.sync_config.filter_collection.blocks_all_room_ephemeral() - ): + block_all_room_ephemeral = ( + sync_result_builder.sync_config.filter_collection.blocks_all_rooms() + or sync_result_builder.sync_config.filter_collection.blocks_all_room_ephemeral() + ) + if block_all_room_ephemeral: ephemeral_by_room: Dict[str, List[JsonDict]] = {} else: now_token, ephemeral_by_room = await self.ephemeral_by_room( @@ -1870,7 +1890,7 @@ async def _generate_sync_entry_for_rooms( ) if not tags_by_room: logger.debug("no-oping sync") - return set(), set(), set(), set() + return set(), set() # 3. Work out which rooms need reporting in the sync response. ignored_users = await self.store.ignored_users(user_id) @@ -1899,6 +1919,7 @@ async def _generate_sync_entry_for_rooms( # joined or archived). async def handle_room_entries(room_entry: "RoomSyncResultBuilder") -> None: logger.debug("Generating room entry for %s", room_entry.room_id) + # Note that this mutates sync_result_builder.{joined,archived}. await self._generate_room_entry( sync_result_builder, room_entry, @@ -1915,20 +1936,7 @@ async def handle_room_entries(room_entry: "RoomSyncResultBuilder") -> None: sync_result_builder.invited.extend(invited) sync_result_builder.knocked.extend(knocked) - # 5. Work out which users have joined or left rooms we're in. We use this - # to build the device_list part of the sync response in - # `_generate_sync_entry_for_device_list`. - ( - newly_joined_or_invited_or_knocked_users, - newly_left_users, - ) = sync_result_builder.calculate_user_changes() - - return ( - set(newly_joined_rooms), - newly_joined_or_invited_or_knocked_users, - set(newly_left_rooms), - newly_left_users, - ) + return set(newly_joined_rooms), set(newly_left_rooms) async def _have_rooms_changed( self, sync_result_builder: "SyncResultBuilder"