From 948e9a67e1f8cdd72a4f3e353ca27a02ef4ea33e Mon Sep 17 00:00:00 2001
From: Saxon <saxon@ausocean.org>
Date: Wed, 17 Apr 2019 09:05:34 +0930
Subject: [PATCH] protocol/rtsp/rtsp.go: simplified RTSP method functions wrap
 a single writeRequest func

---
 protocol/rtsp/rtsp.go | 221 +++++++++++++++++-------------------------
 1 file changed, 90 insertions(+), 131 deletions(-)

diff --git a/protocol/rtsp/rtsp.go b/protocol/rtsp/rtsp.go
index 596fcec3..37b0e6e3 100644
--- a/protocol/rtsp/rtsp.go
+++ b/protocol/rtsp/rtsp.go
@@ -23,18 +23,98 @@ const (
 	setup    = "SETUP"
 )
 
-type Request struct {
-	Method        string
-	URL           *url.URL
-	Proto         string
-	ProtoMajor    int
-	ProtoMinor    int
-	Header        http.Header
-	ContentLength int
-	Body          io.ReadCloser
+type Session struct {
+	cSeq    int
+	conn    net.Conn
+	session string
 }
 
-func (r Request) String() string {
+func NewSession() *Session {
+	return &Session{}
+}
+
+func (s *Session) Describe(urlStr string) (*Response, error) {
+	return s.writeRequest(describe, urlStr, func(req *request) { req.Header.Add("Accept", "application/sdp") }, nil)
+}
+
+func (s *Session) Options(urlStr string) (*Response, error) {
+	return s.writeRequest(options, urlStr, nil, nil)
+}
+
+func (s *Session) Setup(urlStr, transport string) (*Response, error) {
+	return s.writeRequest(
+		setup,
+		urlStr,
+		func(req *request) {
+			req.Header.Add("Transport", transport)
+		},
+		func(resp *Response) {
+			s.session = resp.Header.Get("Session")
+		},
+	)
+}
+
+func (s *Session) Play(urlStr, sessionId string) (*Response, error) {
+	return s.writeRequest(play, urlStr, func(req *request) { req.Header.Add("Session", s.session) }, nil)
+}
+func (s *Session) writeRequest(method, url string, headerOp func(*request), respOp func(*Response)) (*Response, error) {
+	req, err := newRequest(describe, url, s.nextCSeq(), nil)
+	if err != nil {
+		panic(err)
+	}
+
+	if headerOp != nil {
+		headerOp(req)
+	}
+
+	if s.conn == nil {
+		s.conn, err = net.Dial("tcp", req.URL.Host)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	_, err = io.WriteString(s.conn, req.String())
+	if err != nil {
+		return nil, err
+	}
+	res, err := ReadResponse(s.conn)
+	if err != nil {
+		return nil, err
+	}
+
+	if respOp != nil {
+		respOp(res)
+	}
+	return res, nil
+}
+
+func (s *Session) nextCSeq() string {
+	s.cSeq++
+	return strconv.Itoa(s.cSeq)
+}
+
+type request http.Request
+
+func newRequest(method, urlStr, cSeq string, body io.ReadCloser) (*request, error) {
+	u, err := url.Parse(urlStr)
+	if err != nil {
+		return nil, err
+	}
+
+	req := &http.Request{
+		Method:     method,
+		URL:        u,
+		Proto:      "RTSP",
+		ProtoMajor: 1,
+		ProtoMinor: 0,
+		Header:     map[string][]string{"CSeq": []string{cSeq}},
+		Body:       body,
+	}
+	return (*request)(req), nil
+}
+
+func (r *request) String() string {
 	s := fmt.Sprintf("%s %s %s/%d.%d\r\n", r.Method, r.URL, r.Proto, r.ProtoMajor, r.ProtoMinor)
 	for k, v := range r.Header {
 		for _, v := range v {
@@ -49,127 +129,6 @@ func (r Request) String() string {
 	return s
 }
 
-func NewRequest(method, urlStr, cSeq string, body io.ReadCloser) (*Request, error) {
-	u, err := url.Parse(urlStr)
-	if err != nil {
-		return nil, err
-	}
-
-	req := &Request{
-		Method:     method,
-		URL:        u,
-		Proto:      "RTSP",
-		ProtoMajor: 1,
-		ProtoMinor: 0,
-		Header:     map[string][]string{"CSeq": []string{cSeq}},
-		Body:       body,
-	}
-	return req, nil
-}
-
-type Session struct {
-	cSeq    int
-	conn    net.Conn
-	session string
-}
-
-func NewSession() *Session {
-	return &Session{}
-}
-
-func (s *Session) nextCSeq() string {
-	s.cSeq++
-	return strconv.Itoa(s.cSeq)
-}
-
-func (s *Session) Describe(urlStr string) (*Response, error) {
-	req, err := NewRequest(describe, urlStr, s.nextCSeq(), nil)
-	if err != nil {
-		panic(err)
-	}
-
-	req.Header.Add("Accept", "application/sdp")
-
-	if s.conn == nil {
-		s.conn, err = net.Dial("tcp", req.URL.Host)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	_, err = io.WriteString(s.conn, req.String())
-	if err != nil {
-		return nil, err
-	}
-	return ReadResponse(s.conn)
-}
-
-func (s *Session) Options(urlStr string) (*Response, error) {
-	req, err := NewRequest(options, urlStr, s.nextCSeq(), nil)
-	if err != nil {
-		panic(err)
-	}
-
-	if s.conn == nil {
-		s.conn, err = net.Dial("tcp", req.URL.Host)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	_, err = io.WriteString(s.conn, req.String())
-	if err != nil {
-		return nil, err
-	}
-	return ReadResponse(s.conn)
-}
-
-func (s *Session) Setup(urlStr, transport string) (*Response, error) {
-	req, err := NewRequest(setup, urlStr, s.nextCSeq(), nil)
-	if err != nil {
-		panic(err)
-	}
-
-	req.Header.Add("Transport", transport)
-
-	if s.conn == nil {
-		s.conn, err = net.Dial("tcp", req.URL.Host)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	_, err = io.WriteString(s.conn, req.String())
-	if err != nil {
-		return nil, err
-	}
-	resp, err := ReadResponse(s.conn)
-	s.session = resp.Header.Get("Session")
-	return resp, err
-}
-
-func (s *Session) Play(urlStr, sessionId string) (*Response, error) {
-	req, err := NewRequest(play, urlStr+"/", s.nextCSeq(), nil)
-	if err != nil {
-		panic(err)
-	}
-
-	req.Header.Add("Session", sessionId)
-
-	if s.conn == nil {
-		s.conn, err = net.Dial("tcp", req.URL.Host)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	_, err = io.WriteString(s.conn, req.String())
-	if err != nil {
-		return nil, err
-	}
-	return ReadResponse(s.conn)
-}
-
 type closer struct {
 	*bufio.Reader
 	r io.Reader