From 8624db3194789cdc98e4d2a8e0da324609497fb6 Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Wed, 26 Jun 2019 19:30:35 +0100 Subject: [PATCH] Refactor and comment sync device list code --- synapse/handlers/sync.py | 72 ++++++++++++++++++++++++++++++---------- 1 file changed, 54 insertions(+), 18 deletions(-) diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py index f70ebfdee7..4f737d0a12 100644 --- a/synapse/handlers/sync.py +++ b/synapse/handlers/sync.py @@ -1058,38 +1058,74 @@ class SyncHandler(object): newly_left_rooms, newly_left_users, ): + """Generate the DeviceLists section of sync + + Args: + sync_result_builder (SyncResultBuilder) + newly_joined_rooms (set[str]): Set of rooms user has joined since + previous sync + newly_joined_or_invited_users (set[str]): Set of users that have + joined or been invited to a room since previous sync. + newly_left_rooms (set[str]): Set of rooms user has left since + previous sync + newly_left_users (set[str]): Set of users that have left a room + we're in since previous sync + + Returns: + Deferred[DeviceLists] + """ + user_id = sync_result_builder.sync_config.user.to_string() since_token = sync_result_builder.since_token - if since_token and since_token.device_list_key: - # TODO: Be more clever than this, i.e. remove users who we already - # share a room with? - for room_id in newly_joined_rooms: - joined_users = yield self.state.get_current_users_in_room(room_id) - newly_joined_or_invited_users.update(joined_users) + # We're going to mutate these fields, so lets copy them rather than + # assume they won't get used later. + newly_joined_or_invited_users = set(newly_joined_or_invited_users) + newly_left_users = set(newly_left_users) - for room_id in newly_left_rooms: - left_users = yield self.state.get_current_users_in_room(room_id) - newly_left_users.update(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: + # 1. if any users we share a room with have updated their devices, + # and + # 2. 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_who_share_room = yield self.store.get_users_who_share_room_with_user( 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. - changed = users_who_share_room & set(newly_joined_or_invited_users) - - changed_users = yield self.store.get_users_whose_devices_changed( + # Step 1, check for changes in devices of users we share a room with + users_that_have_changed = yield self.store.get_users_whose_devices_changed( since_token.device_list_key, users_who_share_room ) - changed.update(changed_users) + # Step 2, check for newly joined rooms + for room_id in newly_joined_rooms: + joined_users = yield self.state.get_current_users_in_room(room_id) + newly_joined_or_invited_users.update(joined_users) + + # 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_users) + + # Now find users that we no longer track + for room_id in newly_left_rooms: + left_users = yield self.state.get_current_users_in_room(room_id) + newly_left_users.update(left_users) + + # Remove any users that we still share a room with. + newly_left_users -= users_who_share_room defer.returnValue( - DeviceLists( - changed=changed, left=set(newly_left_users) - users_who_share_room - ) + DeviceLists(changed=users_that_have_changed, left=newly_left_users) ) else: defer.returnValue(DeviceLists(changed=[], left=[]))