Faster joins: omit partial rooms from eager syncs until the resync completes (#14870)

* Allow `AbstractSet` in `StrCollection`

Or else frozensets are excluded. This will be useful in an upcoming
commit where I plan to change a function that accepts `List[str]` to
accept `StrCollection` instead.

* `rooms_to_exclude` -> `rooms_to_exclude_globally`

I am about to make use of this exclusion mechanism to exclude rooms for
a specific user and a specific sync. This rename helps to clarify the
distinction between the global config and the rooms to exclude for a
specific sync.

* Better function names for internal sync methods

* Track a list of excluded rooms on SyncResultBuilder

I plan to feed a list of partially stated rooms for this sync to ignore

* Exclude partial state rooms during eager sync

using the mechanism established in the previous commit

* Track un-partial-state stream in sync tokens

So that we can work out which rooms have become fully-stated during a
given sync period.

* Fix mutation of `@cached` return value

This was fouling up a complement test added alongside this PR.
Excluding a room would mean the set of forgotten rooms in the cache
would be extended. This means that room could be erroneously considered
forgotten in the future.

Introduced in #12310, Synapse 1.57.0. I don't think this had any
user-visible side effects (until now).

* SyncResultBuilder: track rooms to force as newly joined

Similar plan as before. We've omitted rooms from certain sync responses;
now we establish the mechanism to reintroduce them into future syncs.

* Read new field, to present rooms as newly joined

* Force un-partial-stated rooms to be newly-joined

for eager incremental syncs only, provided they're still fully stated

* Notify user stream listeners to wake up long polling syncs

* Changelog

* Typo fix

Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>

* Unnecessary list cast

Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>

* Rephrase comment

Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>

* Another comment

Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>

* Fixup merge(?)

* Poke notifier when receiving un-partial-stated msg over replication

* Fixup merge whoops

Thanks MV :)

Co-authored-by: Mathieu Velen <mathieuv@matrix.org>

Co-authored-by: Mathieu Velten <mathieuv@matrix.org>
Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/synapse/streams/events.py b/synapse/streams/events.py
index 619eb7f601..d7084d2358 100644
--- a/synapse/streams/events.py
+++ b/synapse/streams/events.py
@@ -53,11 +53,15 @@ class EventSources:
             *(attribute.type(hs) for attribute in attr.fields(_EventSourcesInner))
         )
         self.store = hs.get_datastores().main
+        self._instance_name = hs.get_instance_name()
 
     def get_current_token(self) -> StreamToken:
         push_rules_key = self.store.get_max_push_rules_stream_id()
         to_device_key = self.store.get_to_device_stream_token()
         device_list_key = self.store.get_device_stream_token()
+        un_partial_stated_rooms_key = self.store.get_un_partial_stated_rooms_token(
+            self._instance_name
+        )
 
         token = StreamToken(
             room_key=self.sources.room.get_current_key(),
@@ -70,6 +74,7 @@ class EventSources:
             device_list_key=device_list_key,
             # Groups key is unused.
             groups_key=0,
+            un_partial_stated_rooms_key=un_partial_stated_rooms_key,
         )
         return token
 
@@ -107,5 +112,6 @@ class EventSources:
             to_device_key=0,
             device_list_key=0,
             groups_key=0,
+            un_partial_stated_rooms_key=0,
         )
         return token