From e34b7d932695c85304d12cc1daf330b75c4728e9 Mon Sep 17 00:00:00 2001
From: aler9 <46489434+aler9@users.noreply.github.com>
Date: Sun, 20 Sep 2020 14:48:37 +0200
Subject: [PATCH] improve performance

---
 connclient.go   | 12 ++++--------
 connserver.go   | 20 +++++++++-----------
 multibuffer.go  | 44 +++++++++++++++++++++++++++++++++++++++-----
 rtcpreceiver.go |  2 +-
 4 files changed, 53 insertions(+), 25 deletions(-)

diff --git a/connclient.go b/connclient.go
index a42b78af..e976226d 100644
--- a/connclient.go
+++ b/connclient.go
@@ -72,7 +72,7 @@ type ConnClient struct {
 	udpLastFrameTimes map[int]*int64
 	udpRtpListeners   map[int]*connClientUDPListener
 	udpRtcpListeners  map[int]*connClientUDPListener
-	tcpFrameReadBuf   *MultiBuffer
+	tcpFrames         *multiFrame
 	playing           bool
 
 	receiverReportTerminate chan struct{}
@@ -150,9 +150,7 @@ func (c *ConnClient) NetConn() net.Conn {
 // ReadFrame reads an InterleavedFrame.
 func (c *ConnClient) ReadFrame() (*InterleavedFrame, error) {
 	c.nconn.SetReadDeadline(time.Now().Add(c.conf.ReadTimeout))
-	frame := &InterleavedFrame{
-		Content: c.tcpFrameReadBuf.Next(),
-	}
+	frame := c.tcpFrames.next()
 	err := frame.Read(c.br)
 	if err != nil {
 		return nil, err
@@ -172,9 +170,7 @@ func (c *ConnClient) readFrameOrResponse() (interface{}, error) {
 	c.br.UnreadByte()
 
 	if b == interleavedFrameMagicByte {
-		frame := &InterleavedFrame{
-			Content: c.tcpFrameReadBuf.Next(),
-		}
+		frame := c.tcpFrames.next()
 		err := frame.Read(c.br)
 		if err != nil {
 			return nil, err
@@ -610,7 +606,7 @@ func (c *ConnClient) Play(u *url.URL) (*Response, error) {
 				return nil, err
 			}
 
-			c.tcpFrameReadBuf = NewMultiBuffer(c.conf.ReadBufferCount, clientTCPFrameReadBufferSize)
+			c.tcpFrames = newMultiFrame(c.conf.ReadBufferCount, clientTCPFrameReadBufferSize)
 
 			// v4lrtspserver sends frames before the response.
 			// ignore them and wait for the response.
diff --git a/connserver.go b/connserver.go
index 45f812df..4c985f49 100644
--- a/connserver.go
+++ b/connserver.go
@@ -33,10 +33,10 @@ type ConnServerConf struct {
 
 // ConnServer is a server-side RTSP connection.
 type ConnServer struct {
-	conf            ConnServerConf
-	br              *bufio.Reader
-	bw              *bufio.Writer
-	tcpFrameReadBuf *MultiBuffer
+	conf      ConnServerConf
+	br        *bufio.Reader
+	bw        *bufio.Writer
+	tcpFrames *multiFrame
 }
 
 // NewConnServer allocates a ConnServer.
@@ -52,10 +52,10 @@ func NewConnServer(conf ConnServerConf) *ConnServer {
 	}
 
 	return &ConnServer{
-		conf:            conf,
-		br:              bufio.NewReaderSize(conf.Conn, serverReadBufferSize),
-		bw:              bufio.NewWriterSize(conf.Conn, serverWriteBufferSize),
-		tcpFrameReadBuf: NewMultiBuffer(conf.ReadBufferCount, clientTCPFrameReadBufferSize),
+		conf:      conf,
+		br:        bufio.NewReaderSize(conf.Conn, serverReadBufferSize),
+		bw:        bufio.NewWriterSize(conf.Conn, serverWriteBufferSize),
+		tcpFrames: newMultiFrame(conf.ReadBufferCount, clientTCPFrameReadBufferSize),
 	}
 }
 
@@ -88,9 +88,7 @@ func (s *ConnServer) ReadFrameOrRequest(timeout bool) (interface{}, error) {
 	s.br.UnreadByte()
 
 	if b == interleavedFrameMagicByte {
-		frame := &InterleavedFrame{
-			Content: s.tcpFrameReadBuf.Next(),
-		}
+		frame := s.tcpFrames.next()
 		err := frame.Read(s.br)
 		if err != nil {
 			return nil, err
diff --git a/multibuffer.go b/multibuffer.go
index 31ce13d1..7a332caf 100644
--- a/multibuffer.go
+++ b/multibuffer.go
@@ -3,8 +3,9 @@ package gortsplib
 // MultiBuffer implements software multi buffering, that allows to reuse
 // existing buffers without creating new ones, increasing performance.
 type MultiBuffer struct {
+	count   int
 	buffers [][]byte
-	curBuf  int
+	cur     int
 }
 
 // NewMultiBuffer allocates a MultiBuffer.
@@ -15,16 +16,49 @@ func NewMultiBuffer(count int, size int) *MultiBuffer {
 	}
 
 	return &MultiBuffer{
+		count:   count,
 		buffers: buffers,
 	}
 }
 
 // Next gets the current buffer and sets the next buffer as the current one.
 func (mb *MultiBuffer) Next() []byte {
-	ret := mb.buffers[mb.curBuf]
-	mb.curBuf += 1
-	if mb.curBuf >= len(mb.buffers) {
-		mb.curBuf = 0
+	ret := mb.buffers[mb.cur]
+	mb.cur += 1
+	if mb.cur >= mb.count {
+		mb.cur = 0
 	}
 	return ret
 }
+
+type multiFrame struct {
+	count  int
+	frames []*InterleavedFrame
+	cur    int
+}
+
+func newMultiFrame(count int, bufsize int) *multiFrame {
+	frames := make([]*InterleavedFrame, count)
+	for i := 0; i < count; i++ {
+		frames[i] = &InterleavedFrame{
+			Content: make([]byte, 0, bufsize),
+		}
+	}
+
+	return &multiFrame{
+		count:  count,
+		frames: frames,
+	}
+}
+
+func (mf *multiFrame) next() *InterleavedFrame {
+	ret := mf.frames[mf.cur]
+	mf.cur += 1
+	if mf.cur >= mf.count {
+		mf.cur = 0
+	}
+
+	ret.Content = ret.Content[:cap(ret.Content)]
+
+	return ret
+}
diff --git a/rtcpreceiver.go b/rtcpreceiver.go
index f2333fb9..b5281d8d 100644
--- a/rtcpreceiver.go
+++ b/rtcpreceiver.go
@@ -56,7 +56,7 @@ func (rr *RtcpReceiver) OnFrame(streamType StreamType, buf []byte) {
 
 	} else {
 		// we can afford to unmarshal all RTCP frames
-		// since they are sent with a frequency much lower than the one of the RTP frames
+		// since they are sent with a frequency much lower than the one of RTP frames
 		frames, err := rtcp.Unmarshal(buf)
 		if err == nil {
 			for _, frame := range frames {