improve performance by avoiding copy() (#21)

Makefile

@@ -69,7 +69,7 @@ define CONFIG_RUN
 #rtpPort: 8002
 #rtcpPort: 8003
 #metrics: yes
-logDestinations: [stdout, file]
+pprof: yes
 
 paths:
   all:

client.go

@@ -118,8 +118,6 @@ type client struct {
 	streamProtocol gortsplib.StreamProtocol
 	streamTracks   map[int]*clientTrack
 	rtcpReceivers  []*gortsplib.RtcpReceiver
-	readBuf        *doubleBuffer
-	writeBuf       *doubleBuffer
 
 	describeRes chan describeRes
 	events      chan clientEvent // only if state = Play and gortsplib.StreamProtocol = TCP
@@ -136,7 +134,6 @@ func newClient(p *program, nconn net.Conn) *client {
 		}),
 		state:        clientStateInitial,
 		streamTracks: make(map[int]*clientTrack),
-		readBuf:      newDoubleBuffer(clientTcpReadBufferSize),
 		done:         make(chan struct{}),
 	}
 
@@ -838,7 +835,6 @@ func (c *client) runPlay(path string) {
 	confp := c.p.findConfForPath(path)
 
 	if c.streamProtocol == gortsplib.StreamProtocolTcp {
-		c.writeBuf = newDoubleBuffer(clientTcpWriteBufferSize)
 		c.events = make(chan clientEvent)
 	}
 
@@ -1030,11 +1026,12 @@ func (c *client) runRecord(path string) {
 
 	} else {
 		frame := &gortsplib.InterleavedFrame{}
+		readBuf := newMultiBuffer(3, clientTcpReadBufferSize)
 
 		readDone := make(chan error)
 		go func() {
 			for {
-				frame.Content = c.readBuf.swap()
+				frame.Content = readBuf.next()
 				frame.Content = frame.Content[:cap(frame.Content)]
 
 				recv, err := c.conn.ReadFrameOrRequest(frame)

main.go

@@ -621,15 +621,11 @@ func (p *program) forwardFrame(path string, trackId int, streamType gortsplib.St
 			}
 
 		} else {
-			buf := c.writeBuf.swap()
-			buf = buf[:len(frame)]
-			copy(buf, frame)
-
 			c.events <- clientEventFrameTcp{
 				frame: &gortsplib.InterleavedFrame{
 					TrackId:    trackId,
 					StreamType: streamType,
-					Content:    buf,
+					Content:    frame,
 				},
 			}
 		}

server-udp.go

@@ -16,8 +16,7 @@ type serverUdp struct {
 	p          *program
 	nconn      *net.UDPConn
 	streamType gortsplib.StreamType
-	readBuf    *doubleBuffer
-	writeBuf   *doubleBuffer
+	readBuf    *multiBuffer
 
 	writeChan chan *udpAddrBufPair
 	done      chan struct{}
@@ -35,8 +34,7 @@ func newServerUdp(p *program, port int, streamType gortsplib.StreamType) (*serve
 		p:          p,
 		nconn:      nconn,
 		streamType: streamType,
-		readBuf:    newDoubleBuffer(clientUdpReadBufferSize),
-		writeBuf:   newDoubleBuffer(clientUdpWriteBufferSize),
+		readBuf:    newMultiBuffer(3, clientUdpReadBufferSize),
 		writeChan:  make(chan *udpAddrBufPair),
 		done:       make(chan struct{}),
 	}
@@ -66,7 +64,7 @@ func (l *serverUdp) run() {
 	}()
 
 	for {
-		buf := l.readBuf.swap()
+		buf := l.readBuf.next()
 		n, addr, err := l.nconn.ReadFromUDP(buf)
 		if err != nil {
 			break
@@ -91,11 +89,5 @@ func (l *serverUdp) close() {
 }
 
 func (l *serverUdp) write(pair *udpAddrBufPair) {
-	// replace input buffer with write buffer
-	buf := l.writeBuf.swap()
-	buf = buf[:len(pair.buf)]
-	copy(buf, pair.buf)
-	pair.buf = buf
-
 	l.writeChan <- pair
 }

source.go

@@ -257,9 +257,9 @@ func (s *source) runUdp(terminate chan struct{}, conn *gortsplib.ConnClient) boo
 		go func(trackId int, l *gortsplib.ConnClientUdpListener) {
 			defer wg.Done()
 
-			doubleBuf := newDoubleBuffer(sourceUdpReadBufferSize)
+			multiBuf := newMultiBuffer(3, sourceUdpReadBufferSize)
 			for {
-				buf := doubleBuf.swap()
+				buf := multiBuf.next()
 
 				n, err := l.Read(buf)
 				if err != nil {
@@ -274,9 +274,9 @@ func (s *source) runUdp(terminate chan struct{}, conn *gortsplib.ConnClient) boo
 		go func(trackId int, l *gortsplib.ConnClientUdpListener) {
 			defer wg.Done()
 
-			doubleBuf := newDoubleBuffer(sourceUdpReadBufferSize)
+			multiBuf := newMultiBuffer(3, sourceUdpReadBufferSize)
 			for {
-				buf := doubleBuf.swap()
+				buf := multiBuf.next()
 
 				n, err := l.Read(buf)
 				if err != nil {
@@ -340,12 +340,12 @@ func (s *source) runTcp(terminate chan struct{}, conn *gortsplib.ConnClient) boo
 	s.p.events <- programEventSourceReady{s}
 
 	frame := &gortsplib.InterleavedFrame{}
-	doubleBuf := newDoubleBuffer(sourceTcpReadBufferSize)
+	multiBuf := newMultiBuffer(3, sourceTcpReadBufferSize)
 
 	tcpConnDone := make(chan error)
 	go func() {
 		for {
-			frame.Content = doubleBuf.swap()
+			frame.Content = multiBuf.next()
 			frame.Content = frame.Content[:cap(frame.Content)]
 
 			err := conn.ReadFrame(frame)

utils.go

@@ -52,27 +52,28 @@ func ipEqualOrInRange(ip net.IP, ips []interface{}) bool {
 	return false
 }
 
-type doubleBuffer struct {
-	buf1   []byte
-	buf2   []byte
-	curBuf bool
+type multiBuffer struct {
+	buffers [][]byte
+	curBuf  int
 }
 
-func newDoubleBuffer(size int) *doubleBuffer {
-	return &doubleBuffer{
-		buf1: make([]byte, size),
-		buf2: make([]byte, size),
+func newMultiBuffer(count int, size int) *multiBuffer {
+	buffers := make([][]byte, count)
+	for i := 0; i < count; i++ {
+		buffers[i] = make([]byte, size)
+	}
+
+	return &multiBuffer{
+		buffers: buffers,
 	}
 }
 
-func (db *doubleBuffer) swap() []byte {
-	var ret []byte
-	if !db.curBuf {
-		ret = db.buf1
-	} else {
-		ret = db.buf2
+func (mb *multiBuffer) next() []byte {
+	ret := mb.buffers[mb.curBuf]
+	mb.curBuf += 1
+	if mb.curBuf >= len(mb.buffers) {
+		mb.curBuf = 0
 	}
-	db.curBuf = !db.curBuf
 	return ret
 }