Add v2 state resolution algorithm

changelog.d/3786.misc

@@ -0,0 +1 @@
+Add initial implementation of new state resolution algorithm

synapse/event_auth.py

@@ -693,7 +693,7 @@ def auth_types_for_event(event):
     auth_types = []
 
     auth_types.append((EventTypes.PowerLevels, "", ))
-    auth_types.append((EventTypes.Member, event.user_id, ))
+    auth_types.append((EventTypes.Member, event.sender, ))
     auth_types.append((EventTypes.Create, "", ))
 
     if event.type == EventTypes.Member:

synapse/python_dependencies.py

@@ -59,6 +59,7 @@
     "prometheus_client": ["prometheus_client"],
     "attrs": ["attr"],
     "netaddr>=0.7.18": ["netaddr"],
+    "networkx>=2.0": ["networkx>=2.0"]
 }
 
 CONDITIONAL_REQUIREMENTS = {

synapse/state/__init__.py

@@ -25,7 +25,7 @@
 
 from synapse.api.constants import EventTypes, RoomVersions
 from synapse.events.snapshot import EventContext
-from synapse.state import v1
+from synapse.state import v1, v2
 from synapse.util.async_helpers import Linearizer
 from synapse.util.caches import get_cache_factor_for
 from synapse.util.caches.expiringcache import ExpiringCache
@@ -616,10 +616,14 @@ def resolve_events_with_factory(room_version, state_sets, event_map, state_map_f
         Deferred[dict[(str, str), str]]:
             a map from (type, state_key) to event_id.
     """
-    if room_version in (RoomVersions.V1, RoomVersions.VDH_TEST,):
+    if room_version == RoomVersions.V1:
         return v1.resolve_events_with_factory(
             state_sets, event_map, state_map_factory,
         )
+    elif room_version == RoomVersions.VDH_TEST:
+        return v2.resolve_events_with_factory(
+            state_sets, event_map, state_map_factory,
+        )
     else:
         # This should only happen if we added a version but forgot to add it to
         # the list above.