Reduce the number of allocations made by localRoomMembers when consuming stream events for push notifications (#2324)

roomserver/api/query.go

@@ -128,6 +128,8 @@ type QueryMembershipForUserResponse struct {
 type QueryMembershipsForRoomRequest struct {
 	// If true, only returns the membership events of "join" membership
 	JoinedOnly bool `json:"joined_only"`
+	// If true, only returns the membership events of local users
+	LocalOnly bool `json:"local_only"`
 	// ID of the room to fetch memberships from
 	RoomID string `json:"room_id"`
 	// Optional - ID of the user sending the request, for checking if the

roomserver/internal/query/query.go

@@ -220,7 +220,7 @@ func (r *Queryer) QueryMembershipsForRoom(
 	if request.Sender == "" {
 		var events []types.Event
 		var eventNIDs []types.EventNID
-		eventNIDs, err = r.DB.GetMembershipEventNIDsForRoom(ctx, info.RoomNID, request.JoinedOnly, false)
+		eventNIDs, err = r.DB.GetMembershipEventNIDsForRoom(ctx, info.RoomNID, request.JoinedOnly, request.LocalOnly)
 		if err != nil {
 			return fmt.Errorf("r.DB.GetMembershipEventNIDsForRoom: %w", err)
 		}

userapi/consumers/syncapi_streamevent.go

@@ -184,6 +184,7 @@ func (s *OutputStreamEventConsumer) localRoomMembers(ctx context.Context, roomID
 	req := &rsapi.QueryMembershipsForRoomRequest{
 		RoomID:     roomID,
 		JoinedOnly: true,
+		LocalOnly:  true,
 	}
 	var res rsapi.QueryMembershipsForRoomResponse