Golang Reader.Skip方法代碼示例

// Send response body if header specifies chunked encoding. rdSize specifies
// the size of each read on Reader, it should be set to be the buffer size of
// the Reader, this parameter is added for testing.
func sendBodyChunked(w io.Writer, r *bufio.Reader, rdSize int) (err error) {
	// debug.Println("Sending chunked body")
	for {
		var s []byte
		// Read chunk size line, ignore chunk extension if any.
		if s, err = r.PeekSlice('\n'); err != nil {
			errl.Println("peek chunk size:", err)
			return
		}
		smid := bytes.IndexByte(s, ';')
		if smid == -1 {
			smid = len(s)
		} else {
			// use error log to find usage of chunk extension
			errl.Printf("got chunk extension: %s\n", s)
		}
		var size int64
		if size, err = ParseIntFromBytes(TrimSpace(s[:smid]), 16); err != nil {
			errl.Println("chunk size invalid:", err)
			return
		}
		/*
			if debug {
				// To debug getting malformed response status line with "0\r\n".
				if c, ok := w.(*clientConn); ok {
					debug.Printf("cli(%s) chunk size %d %#v\n", c.RemoteAddr(), size, string(s))
				}
			}
		*/
		if size == 0 {
			r.Skip(len(s))
			if err = skipCRLF(r); err != nil {
				return
			}
			if _, err = w.Write([]byte(chunkEnd)); err != nil {
				debug.Println("send chunk ending:", err)
			}
			return
		}
		// RFC 2616 19.3 only suggest tolerating single LF for
		// headers, not for chunked encoding. So assume the server will send
		// CRLF. If not, the following parse int may find errors.
		total := len(s) + int(size) + 2 // total data size for this chunk, including ending CRLF
		// PeekSlice will not advance reader, so we can just copy total sized data.
		if err = copyN(w, r, total, rdSize); err != nil {
			debug.Println("copy chunked data:", err)
			return
		}
	}
}

// Send response body if header specifies chunked encoding. rdSize specifies
// the size of each read on Reader, it should be set to be the buffer size of
// the Reader, this parameter is added for testing.
func sendBodyChunked(r *bufio.Reader, w io.Writer, rdSize int) (err error) {
	// debug.Println("Sending chunked body")
	for {
		var s []byte
		// Read chunk size line, ignore chunk extension if any.
		if s, err = r.PeekSlice('\n'); err != nil {
			errl.Println("peeking chunk size:", err)
			return
		}
		// debug.Printf("Chunk size line %s\n", s)
		smid := bytes.IndexByte(s, ';')
		if smid == -1 {
			smid = len(s)
		}
		var size int64
		if size, err = ParseIntFromBytes(TrimSpace(s[:smid]), 16); err != nil {
			errl.Println("chunk size invalid:", err)
			return
		}
		// end of chunked data. As we remove trailer header in request sending
		// to server, there should be no trailer in response.
		// TODO: Is it possible for client request body to have trailers in it?
		if size == 0 {
			r.Skip(len(s))
			skipCRLF(r)
			if _, err = w.Write([]byte(chunkEnd)); err != nil {
				debug.Println("sending chunk ending:", err)
			}
			return
		}
		// The spec section 19.3 only suggest toleranting single LF for
		// headers, not for chunked encoding. So assume the server will send
		// CRLF. If not, the following parse int may find errors.
		total := len(s) + int(size) + 2 // total data size for this chunk, including ending CRLF
		// PeekSlice will not advance reader, so we can just copy total sized data.
		if err = copyN(w, r, total, rdSize); err != nil {
			debug.Println("copying chunked data:", err)
			return
		}
	}
	return
}