s.newCache.Info.LastUpdate = UTCNow()
	s.newCache.Info.NextCycle = cache.Info.NextCycle
	return s.newCache, nil
}

// sendUpdate() should be called on a regular basis when the newCache contains more recent total than previously.
// May or may not send an update upstream.
func (f *folderScanner) sendUpdate() {
	// Send at most an update every minute.
	if f.updates == nil || time.Since(f.lastUpdate) < time.Minute {
		return
	}