From d38c73e9abbd7fe40f4f24d4c96107415e6f15a1 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff <1389908+richvdh@users.noreply.github.com> Date: Wed, 18 May 2022 20:33:57 +0200 Subject: [PATCH] Skip waiting for full state if a StateFilter does not require it (#12498) If `StateFilter` specifies a state set which we will have regardless of state-syncing, then we may as well return it immediately. --- changelog.d/12498.misc | 1 + synapse/storage/state.py | 63 +++++++++++++++++++++++++++++++++++++--- 2 files changed, 60 insertions(+), 4 deletions(-) create mode 100644 changelog.d/12498.misc diff --git a/changelog.d/12498.misc b/changelog.d/12498.misc new file mode 100644 index 000000000..8a00b94fb --- /dev/null +++ b/changelog.d/12498.misc @@ -0,0 +1 @@ +Preparation for faster-room-join work: return subsets of room state which we already have, immediately. diff --git a/synapse/storage/state.py b/synapse/storage/state.py index a6c60de50..e58301a8f 100644 --- a/synapse/storage/state.py +++ b/synapse/storage/state.py @@ -1,4 +1,5 @@ # Copyright 2014-2016 OpenMarket Ltd +# Copyright 2022 The Matrix.org Foundation C.I.C. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. @@ -15,6 +16,7 @@ import logging from typing import ( TYPE_CHECKING, Awaitable, + Callable, Collection, Dict, Iterable, @@ -532,6 +534,44 @@ class StateFilter: new_all, new_excludes, new_wildcards, new_concrete_keys ) + def must_await_full_state(self, is_mine_id: Callable[[str], bool]) -> bool: + """Check if we need to wait for full state to complete to calculate this state + + If we have a state filter which is completely satisfied even with partial + state, then we don't need to await_full_state before we can return it. + + Args: + is_mine_id: a callable which confirms if a given state_key matches a mxid + of a local user + """ + + # TODO(faster_joins): it's not entirely clear that this is safe. In particular, + # there may be circumstances in which we return a piece of state that, once we + # resync the state, we discover is invalid. For example: if it turns out that + # the sender of a piece of state wasn't actually in the room, then clearly that + # state shouldn't have been returned. + # We should at least add some tests around this to see what happens. + + # if we haven't requested membership events, then it depends on the value of + # 'include_others' + if EventTypes.Member not in self.types: + return self.include_others + + # if we're looking for *all* membership events, then we have to wait + member_state_keys = self.types[EventTypes.Member] + if member_state_keys is None: + return True + + # otherwise, consider whose membership we are looking for. If it's entirely + # local users, then we don't need to wait. + for state_key in member_state_keys: + if not is_mine_id(state_key): + # remote user + return True + + # local users only + return False + _ALL_STATE_FILTER = StateFilter(types=frozendict(), include_others=True) _ALL_NON_MEMBER_STATE_FILTER = StateFilter( @@ -544,6 +584,7 @@ class StateGroupStorage: """High level interface to fetching state for event.""" def __init__(self, hs: "HomeServer", stores: "Databases"): + self._is_mine_id = hs.is_mine_id self.stores = stores self._partial_state_events_tracker = PartialStateEventsTracker(stores.main) @@ -675,7 +716,13 @@ class StateGroupStorage: RuntimeError if we don't have a state group for one or more of the events (ie they are outliers or unknown) """ - event_to_groups = await self.get_state_group_for_events(event_ids) + await_full_state = True + if state_filter and not state_filter.must_await_full_state(self._is_mine_id): + await_full_state = False + + event_to_groups = await self.get_state_group_for_events( + event_ids, await_full_state=await_full_state + ) groups = set(event_to_groups.values()) group_to_state = await self.stores.state._get_state_for_groups( @@ -699,7 +746,9 @@ class StateGroupStorage: return {event: event_to_state[event] for event in event_ids} async def get_state_ids_for_events( - self, event_ids: Collection[str], state_filter: Optional[StateFilter] = None + self, + event_ids: Collection[str], + state_filter: Optional[StateFilter] = None, ) -> Dict[str, StateMap[str]]: """ Get the state dicts corresponding to a list of events, containing the event_ids @@ -716,7 +765,13 @@ class StateGroupStorage: RuntimeError if we don't have a state group for one or more of the events (ie they are outliers or unknown) """ - event_to_groups = await self.get_state_group_for_events(event_ids) + await_full_state = True + if state_filter and not state_filter.must_await_full_state(self._is_mine_id): + await_full_state = False + + event_to_groups = await self.get_state_group_for_events( + event_ids, await_full_state=await_full_state + ) groups = set(event_to_groups.values()) group_to_state = await self.stores.state._get_state_for_groups( @@ -802,7 +857,7 @@ class StateGroupStorage: Args: event_ids: events to get state groups for await_full_state: if true, will block if we do not yet have complete - state at this event. + state at these events. """ if await_full_state: await self._partial_state_events_tracker.await_full_state(event_ids)