Method handleRange

rest/handler.go:1728–1740

Detects and partially HTTP content range requests. If the request _can_ accept ranges, sets the "Accept-Ranges" response header to "bytes". If there is no Range: request header, or if its valid is invalid, returns a status of 200, meaning that the caller should return the entire response as usual.

(contentLength uint64)

// It is then the _caller's_ responsibility to set it as the response status code (by calling
// h.response.WriteHeader(status)), and then write the indicated subrange of the response data.
func (h *handler) handleRange(contentLength uint64) (status int, start uint64, end uint64) {
	status = http.StatusOK
	if h.rq.Method == "GET" || h.rq.Method == "HEAD" {
		h.setHeader("Accept-Ranges", "bytes")
		status, start, end = parseHTTPRangeHeader(h.rq.Header.Get("Range"), contentLength)
		if status == http.StatusPartialContent {
			h.setHeader("Content-Range", fmt.Sprintf("bytes %d-%d/%d", start, end, contentLength))
			h.setStatus(http.StatusPartialContent, "Partial Content")
			end += 1 // make end non-inclusive, as in Go slices
		}
	}
	return
}

// Given an HTTP "Range:" header value, parses it and returns the approppriate HTTP status code,
// and the numeric byte range if appropriate: