crypto/cipher: StreamWriter.Closer docs + behavior change

Don't panic when the underlying Writer isn't a Closer. And
document what Close does and clarify that it's not a Flush.

R=golang-dev, agl
CC=golang-dev
https://golang.org/cl/10310043
This commit is contained in:
Brad Fitzpatrick 2013-06-17 07:30:04 -07:00
parent d660688f14
commit 14e52c74bc

View file

@ -25,6 +25,8 @@ func (r StreamReader) Read(dst []byte) (n int, err error) {
// StreamWriter wraps a Stream into an io.Writer. It calls XORKeyStream
// to process each slice of data which passes through. If any Write call
// returns short then the StreamWriter is out of sync and must be discarded.
// A StreamWriter has no internal buffering; Close does not need
// to be called to flush write data.
type StreamWriter struct {
S Stream
W io.Writer
@ -43,8 +45,11 @@ func (w StreamWriter) Write(src []byte) (n int, err error) {
return
}
// Close closes the underlying Writer and returns its Close return value, if the Writer
// is also an io.Closer. Otherwise it returns nil.
func (w StreamWriter) Close() error {
// This saves us from either requiring a WriteCloser or having a
// StreamWriterCloser.
return w.W.(io.Closer).Close()
if c, ok := w.W.(io.Closer); ok {
return c.Close()
}
return nil
}