mime/multipart: delay reading random source

If a user sets his/her own boundary string with SetBoundary,
we don't need to call randomBoundary at all.

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/95760043
This commit is contained in:
Rui Ueyama 2014-07-29 18:24:50 -07:00
parent 678ba85e53
commit fe4fc94b04

View file

@ -25,13 +25,15 @@ type Writer struct {
// writing to w.
func NewWriter(w io.Writer) *Writer {
return &Writer{
w: w,
boundary: randomBoundary(),
w: w,
}
}
// Boundary returns the Writer's boundary.
func (w *Writer) Boundary() string {
if w.boundary == "" {
w.boundary = randomBoundary()
}
return w.boundary
}
@ -65,7 +67,7 @@ func (w *Writer) SetBoundary(boundary string) error {
// FormDataContentType returns the Content-Type for an HTTP
// multipart/form-data with this Writer's Boundary.
func (w *Writer) FormDataContentType() string {
return "multipart/form-data; boundary=" + w.boundary
return "multipart/form-data; boundary=" + w.Boundary()
}
func randomBoundary() string {
@ -89,9 +91,9 @@ func (w *Writer) CreatePart(header textproto.MIMEHeader) (io.Writer, error) {
}
var b bytes.Buffer
if w.lastpart != nil {
fmt.Fprintf(&b, "\r\n--%s\r\n", w.boundary)
fmt.Fprintf(&b, "\r\n--%s\r\n", w.Boundary())
} else {
fmt.Fprintf(&b, "--%s\r\n", w.boundary)
fmt.Fprintf(&b, "--%s\r\n", w.Boundary())
}
// TODO(bradfitz): move this to textproto.MimeHeader.Write(w), have it sort
// and clean, like http.Header.Write(w) does.
@ -157,7 +159,7 @@ func (w *Writer) Close() error {
}
w.lastpart = nil
}
_, err := fmt.Fprintf(w.w, "\r\n--%s--\r\n", w.boundary)
_, err := fmt.Fprintf(w.w, "\r\n--%s--\r\n", w.Boundary())
return err
}