Method writeMultipart

rest/handler.go:1635–1662

(subtype string, callback func(*multipart.Writer) error)

}

func (h *handler) writeMultipart(subtype string, callback func(*multipart.Writer) error) error {
	if !h.requestAccepts("multipart/") {
		return base.HTTPErrorf(http.StatusNotAcceptable, "Response is multipart")
	}

	// Get the output stream. Due to a CouchDB bug, if we're sending to it we need to buffer the
	// output in memory so we can trim the final bytes.
	var output io.Writer
	var buffer bytes.Buffer
	if h.userAgentIs("CouchDB") {
		output = &buffer
	} else {
		output = h.response
	}

	writer := multipart.NewWriter(output)
	h.setHeader("Content-Type",
		fmt.Sprintf("multipart/%s; boundary=%q", subtype, writer.Boundary()))

	err := callback(writer)
	_ = writer.Close()

	if err == nil && output == &buffer {
		// Trim trailing newline; CouchDB is allergic to it:
		_, err = h.response.Write(bytes.TrimRight(buffer.Bytes(), "\r\n"))
	}
	return err
}

func (h *handler) flush() {
	h.response.(http.Flusher).Flush()