speed up routing of udp frames

main.go

@@ -171,6 +171,7 @@ type program struct {
 	serverRtcp          *serverUdp
 	sources             []*source
 	clients             map[*client]struct{}
+	udpClientPublishers map[ipKey]*client
 	paths               map[string]*path
 	cmds                []*exec.Cmd
 	publisherCount      int
@@ -202,6 +203,7 @@ func newProgram(args []string, stdin io.Reader) (*program, error) {
 	p := &program{
 		conf:                conf,
 		clients:             make(map[*client]struct{}),
+		udpClientPublishers: make(map[ipKey]*client),
 		paths:               make(map[string]*path),
 		events:              make(chan programEvent),
 		done:                make(chan struct{}),
@@ -419,17 +421,19 @@ outer:
 			case programEventClientRecord:
 				p.publisherCount += 1
 				evt.client.state = clientStateRecord
+				p.udpClientPublishers[makeIpKey(evt.client.ip())] = evt.client
 				p.paths[evt.client.pathId].publisherSetReady()
 				close(evt.done)
 
 			case programEventClientRecordStop:
 				p.publisherCount -= 1
 				evt.client.state = clientStatePreRecord
+				delete(p.udpClientPublishers, makeIpKey(evt.client.ip()))
 				p.paths[evt.client.pathId].publisherSetNotReady()
 				close(evt.done)
 
 			case programEventClientFrameUdp:
-				client, trackId := p.findClientPublisher(evt.addr, evt.streamType)
+				client, trackId := p.findUdpClientPublisher(evt.addr, evt.streamType)
 				if client == nil {
 					continue
 				}
@@ -544,31 +548,22 @@ func (p *program) findConfForPath(path string) *confPath {
 	return nil
 }
 
-func (p *program) findClientPublisher(addr *net.UDPAddr, streamType gortsplib.StreamType) (*client, int) {
+func (p *program) findUdpClientPublisher(addr *net.UDPAddr, streamType gortsplib.StreamType) (*client, int) {
-	for _, path := range p.paths {
+	c, ok := p.udpClientPublishers[makeIpKey(addr.IP)]
-		cl, ok := path.publisher.(*client)
+	if ok {
-		if !ok {
+		for i, t := range c.streamTracks {
-			continue
-		}
-
-		if cl.streamProtocol != gortsplib.StreamProtocolUdp ||
-			cl.state != clientStateRecord ||
-			!cl.ip().Equal(addr.IP) {
-			continue
-		}
-
-		for i, t := range cl.streamTracks {
 			if streamType == gortsplib.StreamTypeRtp {
 				if t.rtpPort == addr.Port {
-					return cl, i
+					return c, i
 				}
 			} else {
 				if t.rtcpPort == addr.Port {
-					return cl, i
+					return c, i
 				}
 			}
 		}
 	}
+
 	return nil, -1
 }
 

utils.go

@@ -147,3 +147,17 @@ func splitPath(path string) (string, string, error) {
 
 	return comps[0], comps[1], nil
 }
+
+// use a fixed-size array for ip comparison
+type ipKey [net.IPv6len]byte
+
+func makeIpKey(ip net.IP) ipKey {
+	var ret ipKey
+	if len(ip) == net.IPv4len {
+		copy(ret[0:], []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff}) // v4InV6Prefix
+		copy(ret[12:], ip)
+	} else {
+		copy(ret[:], ip)
+	}
+	return ret
+}