Add EventStreamPosition type (#8388)

The idea is to remove some of the places we pass around `int`, where it can represent one of two things:

1. the position of an event in the stream; or
2. a token that partitions the stream, used as part of the stream tokens.

The valid operations are then:

1. did a position happen before or after a token;
2. get all events that happened before or after a token; and
3. get all events between two tokens.

(Note that we don't want to allow other operations as we want to change the tokens to be vector clocks rather than simple ints)

1 files changed, 3 insertions, 3 deletions

diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index 6ee559fd1d..ee271e85e5 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -1138,7 +1138,7 @@ class EventCreationHandler:
             if prev_state_ids:
                 raise AuthError(403, "Changing the room create event is forbidden")
 
-        event_stream_id, max_stream_id = await self.storage.persistence.persist_event(
+        event_pos, max_stream_token = await self.storage.persistence.persist_event(
             event, context=context
         )
 
@@ -1149,7 +1149,7 @@ class EventCreationHandler:
         def _notify():
             try:
                 self.notifier.on_new_room_event(
-                    event, event_stream_id, max_stream_id, extra_users=extra_users
+                    event, event_pos, max_stream_token, extra_users=extra_users
                 )
             except Exception:
                 logger.exception("Error notifying about new room event")
@@ -1161,7 +1161,7 @@ class EventCreationHandler:
             # matters as sometimes presence code can take a while.
             run_in_background(self._bump_active_time, requester.user)
 
-        return event_stream_id
+        return event_pos.stream
 
     async def _bump_active_time(self, user: UserID) -> None:
         try: