Add a cache around server ACL checking (#16360)

* Pre-compiles the server ACLs onto an object per room and
  invalidates them when new events come in.
* Converts the server ACL checking into Rust.

1 files changed, 5 insertions, 2 deletions

diff --git a/synapse/events/validator.py b/synapse/events/validator.py
index a637fadfab..83d9fb5813 100644
--- a/synapse/events/validator.py
+++ b/synapse/events/validator.py
@@ -39,9 +39,9 @@ from synapse.events.utils import (
     CANONICALJSON_MIN_INT,
     validate_canonicaljson,
 )
-from synapse.federation.federation_server import server_matches_acl_event
 from synapse.http.servlet import validate_json_object
 from synapse.rest.models import RequestBodyModel
+from synapse.storage.controllers.state import server_acl_evaluator_from_event
 from synapse.types import EventID, JsonDict, RoomID, StrCollection, UserID
 
 
@@ -106,7 +106,10 @@ class EventValidator:
             self._validate_retention(event)
 
         elif event.type == EventTypes.ServerACL:
-            if not server_matches_acl_event(config.server.server_name, event):
+            server_acl_evaluator = server_acl_evaluator_from_event(event)
+            if not server_acl_evaluator.server_matches_acl_event(
+                config.server.server_name
+            ):
                 raise SynapseError(
                     400, "Can't create an ACL event that denies the local server"
                 )