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