func (d *dataUsageCache) isCompacted(h dataUsageHash) bool {
	due, ok := d.Cache[h.Key()]
	if !ok {
		return false
	}
	return due.Compacted
}

// findChildrenCopy returns a copy of the children of the supplied hash.
func (d *dataUsageCache) findChildrenCopy(h dataUsageHash) dataUsageHashMap {
	ch := d.Cache[h.String()].Children
	res := make(dataUsageHashMap, len(ch))
	for k := range ch {
		res[k] = struct{}{}
	}

	for {
		select {
		case <-done:
			return ctx.Err()
		default:
		}
		var abandonedChildren dataUsageHashMap
		if !into.Compacted {
			abandonedChildren = f.oldCache.findChildrenCopy(thisHash)
		}

		// If there are lifecycle rules for the prefix.
		_, prefix := path2BucketObjectWithBasePath(f.root, folder.name)
		var activeLifeCycle *lifecycle.Lifecycle