From d998b65a9cfacb802052f6c602311243404f5f1e Mon Sep 17 00:00:00 2001
From: Mark van Renswoude <mark@x2software.net>
Date: Thu, 13 Aug 2020 11:24:17 +0200
Subject: [PATCH] Attempt at making the connection more robust

---
 CameraStream.cs | 46 ++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 44 insertions(+), 2 deletions(-)

diff --git a/CameraStream.cs b/CameraStream.cs
index c730e67..2c1b8fd 100644
--- a/CameraStream.cs
+++ b/CameraStream.cs
@@ -29,7 +29,7 @@ namespace IPCamAppBar
 
         private readonly CancellationTokenSource cancelTaskTokenSource = new CancellationTokenSource();
         private Task streamTask;
-
+        private DataMonitor dataMonitor;
 
         protected CameraStream()
         {
@@ -89,12 +89,24 @@ namespace IPCamAppBar
                         cancellationToken.ThrowIfCancellationRequested();
                     }
 
+
                     if (response.StatusCode != HttpStatusCode.OK)
                         throw new WebException(response.StatusDescription);
 
                     using (var responseStream = response.GetResponseStream())
                     {
-                        await ReadFrames(responseStream, cancellationToken);
+                        var dataMonitorCancellationTokenSource = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
+                        dataMonitor = new DataMonitor(dataMonitorCancellationTokenSource, TimeSpan.FromSeconds(15));
+
+                        try
+                        { 
+                            await ReadFrames(responseStream, dataMonitorCancellationTokenSource.Token);
+                        }
+                        catch (TaskCanceledException)
+                        {
+                            if (!dataMonitorCancellationTokenSource.IsCancellationRequested)
+                                throw;
+                        }
                     }
                 }
                 catch (TaskCanceledException)
@@ -121,6 +133,7 @@ namespace IPCamAppBar
 
         protected virtual void OnFrame(FrameEventArgs args)
         {
+            dataMonitor.Reset();
             Frame?.Invoke(this, args);
         }
 
@@ -156,6 +169,35 @@ namespace IPCamAppBar
 
             return -1;
         }
+    }
 
+
+    internal class DataMonitor
+    {
+        private readonly CancellationTokenSource cancellationTokenSource;
+        private readonly long timeout;
+
+        private readonly Timer timeoutTimer;
+
+
+        public DataMonitor(CancellationTokenSource cancellationTokenSource, TimeSpan timeout)
+        {
+            this.cancellationTokenSource = cancellationTokenSource;
+            this.timeout = (long)timeout.TotalMilliseconds;
+
+            timeoutTimer = new Timer(Tick, null, this.timeout, -1);
+        }
+
+
+        public void Reset()
+        {
+            timeoutTimer.Change(timeout, -1);
+        }
+
+
+        private void Tick(object state)
+        {
+            cancellationTokenSource.Cancel();
+        }
     }
 }