func()

in garbage/nethttp.go [2328:2416]

• 75 lines of code
• 24 McCabe index (conditional complexity)

func (req *Request) write(w io.Writer, usingProxy bool, extraHeaders Header) error {

	host := cleanHost(req.Host)
	if host == "" {
		if req.URL == nil {
			return errors.New("http: Request.Write on Request with no Host or URL set")
		}
		host = cleanHost(req.URL.Host)
	}

	host = removeZone(host)

	ruri := req.URL.RequestURI()
	if usingProxy && req.URL.Scheme != "" && req.URL.Opaque == "" {
		ruri = req.URL.Scheme + "://" + host + ruri
	} else if req.Method == "CONNECT" && req.URL.Path == "" {

		ruri = host
	}

	// Wrap the writer in a bufio Writer if it's not already buffered.
	// Don't always call NewWriter, as that forces a bytes.Buffer
	// and other small bufio Writers to have a minimum 4k buffer
	// size.
	var bw *bufio.Writer
	if _, ok := w.(io.ByteWriter); !ok {
		bw = bufio.NewWriter(w)
		w = bw
	}

	_, err := fmt.Fprintf(w, "%s %s HTTP/1.1\r\n", valueOrDefault(req.Method, "GET"), ruri)
	if err != nil {
		return err
	}

	_, err = fmt.Fprintf(w, "Host: %s\r\n", host)
	if err != nil {
		return err
	}

	userAgent := defaultUserAgent
	if req.Header != nil {
		if ua := req.Header["User-Agent"]; len(ua) > 0 {
			userAgent = ua[0]
		}
	}
	if userAgent != "" {
		_, err = fmt.Fprintf(w, "User-Agent: %s\r\n", userAgent)
		if err != nil {
			return err
		}
	}

	tw, err := newTransferWriter(req)
	if err != nil {
		return err
	}
	err = tw.WriteHeader(w)
	if err != nil {
		return err
	}

	err = req.Header.WriteSubset(w, reqWriteExcludeHeader)
	if err != nil {
		return err
	}

	if extraHeaders != nil {
		err = extraHeaders.Write(w)
		if err != nil {
			return err
		}
	}

	_, err = io.WriteString(w, "\r\n")
	if err != nil {
		return err
	}

	err = tw.WriteBody(w)
	if err != nil {
		return err
	}

	if bw != nil {
		return bw.Flush()
	}
	return nil
}