Allow enable/disable of autoretry

cam.go

@@ -23,9 +23,11 @@ type Camera struct {
 	Password  string // optional password for basic authentication
 	Log       bool   // should log
 	LastFrame *Frame
+	AutoRetry bool          // should automatically retry
 	body      io.ReadCloser // a reference to the http response body
 	listeners []chan Frame  // slice of channels returned from the Subscribe method
 	mutex     sync.Mutex
+	locked    bool // lock to prevent multiple keepalive goroutines
 }
 
 // A Frame is a container for jpeg data from a Camera
@@ -97,7 +99,12 @@ func (cam *Camera) logf(t string, l ...interface{}) {
 }
 
 func (cam *Camera) keepalive() {
+	if cam.locked {
+		return
+	}
+	cam.locked = true
 	time.Sleep(time.Second * 10)
+	cam.locked = false
 	if cam.LastFrame != nil &&
 		time.Since(cam.LastFrame.Timestamp) > time.Second*10 {
 		cam.stop()
@@ -109,8 +116,11 @@ func (cam *Camera) keepalive() {
 // read will read data from the response until eof or the response
 // body is closed
 func (cam *Camera) read(mr *multipart.Reader) {
-	// Never stop reading
 	defer func() {
+		if !cam.AutoRetry {
+			return
+		}
+
 		cam.logf("[%s] Reconnecting", cam.Name)
 		err := cam.start()
 		for err != nil {
@@ -123,7 +133,9 @@ func (cam *Camera) read(mr *multipart.Reader) {
 	start := time.Now()
 	frames := 0
 
-	go cam.keepalive()
+	if cam.AutoRetry {
+		go cam.keepalive()
+	}
 
 	for i := 0; true; i++ {
 		part, err := mr.NextPart()
@@ -186,11 +198,9 @@ func (cam *Camera) Subscribe() (<-chan Frame, error) {
 	if len(cam.listeners) == 0 {
 		err = cam.start()
 	}
-	go func() {
-		cam.mutex.Lock()
-		cam.listeners = append(cam.listeners, l)
-		cam.mutex.Unlock()
-	}()
+	cam.mutex.Lock()
+	cam.listeners = append(cam.listeners, l)
+	cam.mutex.Unlock()
 	return l, err
 }
 
@@ -200,22 +210,20 @@ func (cam *Camera) Subscribe() (<-chan Frame, error) {
 func (cam *Camera) Unsubscribe(unsub <-chan Frame) bool {
 	for i, l := range cam.listeners {
 		if unsub == l {
-			go func() {
-				if len(cam.listeners) == 1 {
-					cam.stop()
-					cam.mutex.Lock()
-					cam.listeners = make([]chan Frame, 0)
-					cam.mutex.Unlock()
-				} else {
-					cam.mutex.Lock()
-					cam.listeners = append(
-						cam.listeners[:i],
-						cam.listeners[i+1:]...,
-					)
-					cam.mutex.Unlock()
-				}
-				close(l)
-			}()
+			if len(cam.listeners) == 1 {
+				cam.stop()
+				cam.mutex.Lock()
+				cam.listeners = make([]chan Frame, 0)
+				cam.mutex.Unlock()
+			} else {
+				cam.mutex.Lock()
+				cam.listeners = append(
+					cam.listeners[:i],
+					cam.listeners[i+1:]...,
+				)
+				cam.mutex.Unlock()
+			}
+			close(l)
 			return true
 		}
 	}