Do not do analysis if luxsrv is unreachable

Author: ivkos

cmd/luxaudio/main.go

@@ -24,15 +24,21 @@ func main() {
 		context.Free()
 	}()
 
-	// Create UDP socket
-	conn := utils.GetUDPConn(f.Host, f.Port)
-	defer func() { _ = conn.Close() }()
+	// Create UDP sockets
+	effectConn := utils.GetUDPConn(f.Host, f.Port)
+	pingerConn := utils.GetUDPConn(f.Host, f.Port)
+	defer func() {
+		_ = effectConn.Close()
+		_ = pingerConn.Close()
+	}()
 
 	payloadSender := func(ledData []byte) {
-		_, err := conn.Write(led.MakeRawModeLuxPayload(uint8(f.LedCount), ledData))
+		_, err := effectConn.Write(led.MakeRawModeLuxPayload(uint8(f.LedCount), ledData))
 		utils.CheckErr(err)
 	}
 
+	pinger := utils.NewPinger(pingerConn, 2*time.Second, f.Verbose)
+
 	analyzer := analyzers.NewSmartAnalyzer(
 		f.FftSize,
 		f.LedCount,
@@ -51,6 +57,7 @@ func main() {
 		malgo.SampleSizeInBytes(captureConfig.Capture.Format),
 		int(captureConfig.Capture.Channels),
 		queue,
+		pinger,
 	)
 
 	if f.Verbose {

internal/audio/framereceiver.go

@@ -11,19 +11,25 @@ type FrameReceiver struct {
 	sampleSizeInBytes int
 	channels          int
 	queue             *analyzers.Queue
+	pinger            *utils.Pinger
 }
 
 type SampleFormat float32
 
-func NewFrameReceiver(sampleSizeInBytes int, channels int, queue *analyzers.Queue) *FrameReceiver {
+func NewFrameReceiver(sampleSizeInBytes int, channels int, queue *analyzers.Queue, pinger *utils.Pinger) *FrameReceiver {
 	return &FrameReceiver{
 		sampleSizeInBytes: sampleSizeInBytes,
 		channels:          channels,
 		queue:             queue,
+		pinger:            pinger,
 	}
 }
 
 func (fr *FrameReceiver) OnReceive(data []byte, frameCount uint32) {
+	if !fr.pinger.IsReachable {
+		return
+	}
+
 	convertedData := make([]SampleFormat, len(data)/fr.sampleSizeInBytes)
 	err := binary.Read(bytes.NewReader(data), binary.LittleEndian, &convertedData)
 	utils.CheckErr(err)

internal/led/led.go

@@ -4,7 +4,8 @@ type EffectMode byte
 
 // TODO Implement other modes
 const (
-	Raw EffectMode = iota
+	Raw  EffectMode = 0x00
+	Ping EffectMode = 0xFF
 )
 
 var Header = []byte{0x4C, 0x58}
@@ -27,3 +28,7 @@ func MakeRawModeLuxPayload(ledCount uint8, grbData []byte) []byte {
 
 	return MakeLuxPayload(Raw, effectPayload)
 }
+
+func MakePingPayload() []byte {
+	return MakeLuxPayload(Ping, []byte{})
+}

internal/utils/pinger.go

@@ -0,0 +1,92 @@
+package utils
+
+import (
+	"github.com/ivkos/luxaudio/internal/led"
+	"log"
+	"net"
+	"time"
+)
+
+type Pinger struct {
+	conn     *net.UDPConn
+	interval time.Duration
+	timeout  time.Duration
+	verbose  bool
+
+	IsReachable bool
+}
+
+func NewPinger(conn *net.UDPConn, interval time.Duration, verbose bool) *Pinger {
+	pinger := &Pinger{
+		conn:     conn,
+		interval: interval,
+		timeout:  1 * time.Second,
+		verbose:  verbose,
+
+		IsReachable: true,
+	}
+
+	go pinger.start()
+
+	return pinger
+}
+
+func (pinger *Pinger) start() {
+	timer := time.NewTimer(0)
+	pingPayload := led.MakePingPayload()
+
+	for {
+		timer.Reset(pinger.interval)
+		<-timer.C
+
+		_, err := pinger.conn.Write(pingPayload)
+		if err != nil {
+			pinger.setReachable(false)
+			pinger.logVerbose("WARN: Could not write ping payload: %v", err)
+			continue
+		}
+
+		err = pinger.conn.SetReadDeadline(time.Now().Add(pinger.timeout))
+		if err != nil {
+			pinger.setReachable(false)
+			pinger.logVerbose("WARN: Could not set ping deadline: %v", err)
+			continue
+		}
+
+		result := make([]byte, 1)
+		n, err := pinger.conn.Read(result)
+		if err != nil {
+			pinger.logVerbose("WARN: Could not read ping response: %v", err)
+			pinger.setReachable(false)
+			continue
+		}
+
+		if n != 1 {
+			pinger.logVerbose("WARN: Ping response has unexpected length %d", n)
+			pinger.setReachable(false)
+			continue
+		}
+
+		if result[0] != '1' {
+			pinger.logVerbose("WARN: Ping response is unexpected: %x", result[0])
+			pinger.setReachable(false)
+			continue
+		}
+
+		pinger.setReachable(true)
+	}
+}
+
+func (pinger *Pinger) setReachable(reachable bool) {
+	if reachable != pinger.IsReachable {
+		log.Printf("Reachable = %t", reachable)
+	}
+
+	pinger.IsReachable = reachable
+}
+
+func (pinger *Pinger) logVerbose(format string, v ...interface{}) {
+	if pinger.verbose {
+		log.Printf(format, v...)
+	}
+}