Calculate the forward extremeties once

1 files changed, 6 insertions, 70 deletions

diff --git a/synapse/storage/event_federation.py b/synapse/storage/event_federation.py
index 53feaa1960..f0aa2193fb 100644
--- a/synapse/storage/event_federation.py
+++ b/synapse/storage/event_federation.py
@@ -235,80 +235,21 @@ class EventFederationStore(SQLBaseStore):
             ],
         )
 
-        self._update_extremeties(txn, events)
+        self._update_backward_extremeties(txn, events)
 
-    def _update_extremeties(self, txn, events):
-        """Updates the event_*_extremities tables based on the new/updated
+    def _update_backward_extremeties(self, txn, events):
+        """Updates the event_backward_extremities tables based on the new/updated
         events being persisted.
 
         This is called for new events *and* for events that were outliers, but
-        are are now being persisted as non-outliers.
+        are now being persisted as non-outliers.
+
+        Forward extremities are handled when we first start persisting the events.
         """
         events_by_room = {}
         for ev in events:
             events_by_room.setdefault(ev.room_id, []).append(ev)
 
-        for room_id, room_events in events_by_room.items():
-            prevs = [
-                e_id for ev in room_events for e_id, _ in ev.prev_events
-                if not ev.internal_metadata.is_outlier()
-            ]
-            if prevs:
-                txn.execute(
-                    "DELETE FROM event_forward_extremities"
-                    " WHERE room_id = ?"
-                    " AND event_id in (%s)" % (
-                        ",".join(["?"] * len(prevs)),
-                    ),
-                    [room_id] + prevs,
-                )
-
-        query = (
-            "INSERT INTO event_forward_extremities (event_id, room_id)"
-            " SELECT ?, ? WHERE NOT EXISTS ("
-            " SELECT 1 FROM event_edges WHERE prev_event_id = ?"
-            " )"
-        )
-
-        txn.executemany(
-            query,
-            [
-                (ev.event_id, ev.room_id, ev.event_id) for ev in events
-                if not ev.internal_metadata.is_outlier()
-            ]
-        )
-
-        # We now insert into stream_ordering_to_exterm a mapping from room_id,
-        # new stream_ordering to new forward extremeties in the room.
-        # This allows us to later efficiently look up the forward extremeties
-        # for a room before a given stream_ordering
-        max_stream_ord = max(
-            ev.internal_metadata.stream_ordering for ev in events
-        )
-        new_extrem = {}
-        for room_id in events_by_room:
-            event_ids = self._simple_select_onecol_txn(
-                txn,
-                table="event_forward_extremities",
-                keyvalues={"room_id": room_id},
-                retcol="event_id",
-            )
-            new_extrem[room_id] = event_ids
-
-        self._simple_insert_many_txn(
-            txn,
-            table="stream_ordering_to_exterm",
-            values=[
-                {
-                    "room_id": room_id,
-                    "event_id": event_id,
-                    "stream_ordering": max_stream_ord,
-                }
-                for room_id, extrem_evs in new_extrem.items()
-                for event_id in extrem_evs
-            ]
-        )
-
         query = (
             "INSERT INTO event_backward_extremities (event_id, room_id)"
             " SELECT ?, ? WHERE NOT EXISTS ("
@@ -339,11 +280,6 @@ class EventFederationStore(SQLBaseStore):
             ]
         )
 
-        for room_id in events_by_room:
-            txn.call_after(
-                self.get_latest_event_ids_in_room.invalidate, (room_id,)
-            )
-
     def get_forward_extremeties_for_room(self, room_id, stream_ordering):
         # We want to make the cache more effective, so we clamp to the last
         # change before the given ordering.