Version:    resyncMetaVersion,
	}
}

var contentRangeRegexp = regexp.MustCompile(`bytes ([0-9]+)-([0-9]+)/([0-9]+|\\*)`)

// parse size from content-range header
func parseSizeFromContentRange(h http.Header) (sz int64, err error) {
	cr := h.Get(xhttp.ContentRange)
	if cr == "" {
		return sz, fmt.Errorf("Content-Range not set")
	}
	parts := contentRangeRegexp.FindStringSubmatch(cr)

	closeReader := func() { obj.Close() }
	reader, err := fn(obj, h, closeReader)
	if err != nil {
		return nil, proxy, err
	}
	reader.ObjInfo = oi.Clone()
	if rs != nil {
		contentSize, err := parseSizeFromContentRange(h)
		if err != nil {
			return nil, proxy, err
		}
		reader.ObjInfo.Size = contentSize
	}

	return reader, proxyResult{Proxy: true}, nil
}