diff options
| -rw-r--r-- | synapse/storage/databases/main/event_federation.py | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/synapse/storage/databases/main/event_federation.py b/synapse/storage/databases/main/event_federation.py index b32b85646a..00958f15e4 100644 --- a/synapse/storage/databases/main/event_federation.py +++ b/synapse/storage/databases/main/event_federation.py @@ -1062,6 +1062,59 @@ class EventFederationWorkerStore(SignatureWorkerStore, EventsWorkerStore, SQLBas return min_depth_event_id, current_min_depth + async def get_prev_events_for_creating_event_in_room(self, room_id: str) -> List[str]: + """ + Gets up to 10 event IDs which are suitable for use as `prev_events` + when creating an event in the given room. + + If a full-state room: + Gets up to 10 of the forward extremities of the room DAG. + See `get_prev_events_for_full_state_room`. + + If a partial-state room: + Gets up to 10 of the forward extremities of the room subgraph + in which we pretend other homeservers haven't sent any events. + See `_get_prev_events_for_partial_state_room_from_join_event_txn`. + Gets a subset of the current forward extremities in the given room. + + Limits the result to 10 extremities, so that we can avoid creating + events which refer to hundreds of prev_events. + + Args: + room_id: room_id + + Returns: + The event IDs of up to 10 event IDs which are suitable for use as + `prev_events`. + """ + + return await self.db_pool.runInteraction( + "get_prev_events_for_creating_event_in_room", + self._get_prev_events_for_creating_event_in_room_txn, + room_id, + ) + + def _get_prev_events_for_creating_event_in_room_txn( + self, txn: LoggingTransaction, room_id: str + ) -> List[str]: + # Find out if the room is partial-stated, getting the partial join event ID + # if it is. + join_event_id = self.db_pool.simple_select_one_onecol_txn( + txn, + table="partial_state_rooms", + keyvalues={"room_id": room_id}, + retcol="join_event_id", + allow_none=True, + ) + + if join_event_id is None: + # This is not a partial-state room. + return self._get_prev_events_for_full_state_room_txn(txn, room_id) + else: + return self._get_prev_events_for_partial_state_room_from_join_event_txn( + txn, join_event_id + ) + async def get_prev_events_for_full_state_room(self, room_id: str) -> List[str]: """ Gets a subset of the current forward extremities in the given room. |