Method QueryMissingEvents

roomserver/internal/query/query.go:364–420

QueryMissingEvents implements api.RoomserverInternalAPI

(
	ctx context.Context,
	request *api.QueryMissingEventsRequest,
	response *api.QueryMissingEventsResponse,
)

// QueryMissingEvents implements api.RoomserverInternalAPI
func (r *Queryer) QueryMissingEvents(
	ctx context.Context,
	request *api.QueryMissingEventsRequest,
	response *api.QueryMissingEventsResponse,
) error {
	var front []string
	eventsToFilter := make(map[string]bool, len(request.LatestEvents))
	visited := make(map[string]bool, request.Limit) // request.Limit acts as a hint to size.
	for _, id := range request.EarliestEvents {
		visited[id] = true
	}

	for _, id := range request.LatestEvents {
		if !visited[id] {
			front = append(front, id)
			eventsToFilter[id] = true
		}
	}
	events, err := r.DB.EventsFromIDs(ctx, front)
	if err != nil {
		return err
	}
	if len(events) == 0 {
		return nil // we are missing the events being asked to search from, give up.
	}
	info, err := r.DB.RoomInfo(ctx, events[0].RoomID())
	if err != nil {
		return err
	}
	if info == nil || info.IsStub() {
		return fmt.Errorf("missing RoomInfo for room %s", events[0].RoomID())
	}

	resultNIDs, err := helpers.ScanEventTree(ctx, r.DB, info, front, visited, request.Limit, request.ServerName)
	if err != nil {
		return err
	}

	loadedEvents, err := helpers.LoadEvents(ctx, r.DB, resultNIDs)
	if err != nil {
		return err
	}

	response.Events = make([]*gomatrixserverlib.HeaderedEvent, 0, len(loadedEvents)-len(eventsToFilter))
	for _, event := range loadedEvents {
		if !eventsToFilter[event.EventID()] {
			roomVersion, verr := r.roomVersion(event.RoomID())
			if verr != nil {
				return verr
			}

			response.Events = append(response.Events, event.Headered(roomVersion))
		}
	}

	return err
}