Fix transaction issues in events table in PSQL (#2165)

* Revert "Revert "Fix storage bug in PSQL events table""

This reverts commit cf447dd52a0015c2c5b10813ed11e59a3712607e.

* Membership updater to use updater

* Fix membership updater to use transactions properly

2 files changed, 6 insertions, 5 deletions

diff --git a/roomserver/storage/postgres/events_table.go b/roomserver/storage/postgres/events_table.go
index ece1d9e3..c136f039 100644
--- a/roomserver/storage/postgres/events_table.go
+++ b/roomserver/storage/postgres/events_table.go
@@ -74,7 +74,7 @@ const insertEventSQL = "" +
 	"INSERT INTO roomserver_events AS e (room_nid, event_type_nid, event_state_key_nid, event_id, reference_sha256, auth_event_nids, depth, is_rejected)" +
 	" VALUES ($1, $2, $3, $4, $5, $6, $7, $8)" +
 	" ON CONFLICT ON CONSTRAINT roomserver_event_id_unique DO UPDATE" +
-	" SET is_rejected = $8 WHERE e.is_rejected = FALSE" +
+	" SET is_rejected = $8 WHERE e.event_id = $4 AND e.is_rejected = FALSE" +
 	" RETURNING event_nid, state_snapshot_nid"
 
 const selectEventSQL = "" +
@@ -192,7 +192,8 @@ func (s *eventStatements) InsertEvent(
 ) (types.EventNID, types.StateSnapshotNID, error) {
 	var eventNID int64
 	var stateNID int64
-	err := s.insertEventStmt.QueryRowContext(
+	stmt := sqlutil.TxStmt(txn, s.insertEventStmt)
+	err := stmt.QueryRowContext(
 		ctx, int64(roomNID), int64(eventTypeNID), int64(eventStateKeyNID),
 		eventID, referenceSHA256, eventNIDsAsArray(authEventNIDs), depth,
 		isRejected,
diff --git a/roomserver/storage/shared/membership_updater.go b/roomserver/storage/shared/membership_updater.go
index f1f589a3..66ac2f5b 100644
--- a/roomserver/storage/shared/membership_updater.go
+++ b/roomserver/storage/shared/membership_updater.go
@@ -136,7 +136,7 @@ func (u *MembershipUpdater) SetToJoin(senderUserID string, eventID string, isUpd
 		}
 
 		// Look up the NID of the new join event
-		nIDs, err := u.d.EventNIDs(u.ctx, []string{eventID})
+		nIDs, err := u.d.eventNIDs(u.ctx, u.txn, []string{eventID})
 		if err != nil {
 			return fmt.Errorf("u.d.EventNIDs: %w", err)
 		}
@@ -170,7 +170,7 @@ func (u *MembershipUpdater) SetToLeave(senderUserID string, eventID string) ([]s
 		}
 
 		// Look up the NID of the new leave event
-		nIDs, err := u.d.EventNIDs(u.ctx, []string{eventID})
+		nIDs, err := u.d.eventNIDs(u.ctx, u.txn, []string{eventID})
 		if err != nil {
 			return fmt.Errorf("u.d.EventNIDs: %w", err)
 		}
@@ -196,7 +196,7 @@ func (u *MembershipUpdater) SetToKnock(event *gomatrixserverlib.Event) (bool, er
 		}
 		if u.membership != tables.MembershipStateKnock {
 			// Look up the NID of the new knock event
-			nIDs, err := u.d.EventNIDs(u.ctx, []string{event.EventID()})
+			nIDs, err := u.d.eventNIDs(u.ctx, u.txn, []string{event.EventID()})
 			if err != nil {
 				return fmt.Errorf("u.d.EventNIDs: %w", err)
 			}