Remove stream ordering from Metadata dict (#8452)

There's no need for it to be in the dict as well as the events table. Instead,
we store it in a separate attribute in the EventInternalMetadata object, and
populate that on load.

This means that we can rely on it being correctly populated for any event which
has been persited to the database.

1 files changed, 3 insertions, 0 deletions

diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index 1a8144405a..5ac2fc5656 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -3008,6 +3008,9 @@ class FederationHandler(BaseHandler):
         elif event.internal_metadata.is_outlier():
             return
 
+        # the event has been persisted so it should have a stream ordering.
+        assert event.internal_metadata.stream_ordering
+
         event_pos = PersistedEventPosition(
             self._instance_name, event.internal_metadata.stream_ordering
         )