+
+var rangeRe = regexp.MustCompile(`^bytes=0-([0-9]*)$`)
+
+func applyRangeHdr(w http.ResponseWriter, r *http.Request, rdr keepclient.ReadCloserWithLen) (io.Reader, int) {
+ w.Header().Set("Accept-Ranges", "bytes")
+ hdr := r.Header.Get("Range")
+ fields := rangeRe.FindStringSubmatch(hdr)
+ if fields == nil {
+ return rdr, http.StatusOK
+ }
+ rangeEnd, err := strconv.ParseInt(fields[1], 10, 64)
+ if err != nil {
+ // Empty or too big for int64 == send entire content
+ return rdr, http.StatusOK
+ }
+ if uint64(rangeEnd) >= rdr.Len() {
+ return rdr, http.StatusOK
+ }
+ w.Header().Set("Content-Length", fmt.Sprintf("%d", rangeEnd+1))
+ w.Header().Set("Content-Range", fmt.Sprintf("bytes %d-%d/%d", 0, rangeEnd, rdr.Len()))
+ return &io.LimitedReader{R: rdr, N: rangeEnd + 1}, http.StatusPartialContent
+}
+
+func applyContentDispositionHdr(w http.ResponseWriter, r *http.Request, filename string, isAttachment bool) {
+ disposition := "inline"
+ if isAttachment {
+ disposition = "attachment"
+ }
+ if strings.ContainsRune(r.RequestURI, '?') {
+ // Help the UA realize that the filename is just
+ // "filename.txt", not
+ // "filename.txt?disposition=attachment".
+ //
+ // TODO(TC): Follow advice at RFC 6266 appendix D
+ disposition += "; filename=" + strconv.QuoteToASCII(filename)
+ }
+ if disposition != "inline" {
+ w.Header().Set("Content-Disposition", disposition)
+ }
+}