Throw MqttCommunicationException if access to underlying source failed.

MQTTnet.Core/Serializer/MqttPacketReader.cs

@@ -13,6 +13,8 @@ namespace MQTTnet.Core.Serializer
         private readonly MemoryStream _remainingData = new MemoryStream();
         private readonly IMqttCommunicationChannel _source;
 
+        private int _remainingLength;
+
         public MqttPacketReader(IMqttCommunicationChannel source)
         {
             _source = source ?? throw new ArgumentNullException(nameof(source));
@@ -22,8 +24,6 @@ namespace MQTTnet.Core.Serializer
 
         public byte FixedHeader { get; private set; }
 
-        public int RemainingLength { get; private set; }
-
         public bool EndOfRemainingData => _remainingData.Position == _remainingData.Length;
 
         public async Task ReadToEndAsync()
@@ -31,54 +31,18 @@ namespace MQTTnet.Core.Serializer
             await ReadFixedHeaderAsync();
             await ReadRemainingLengthAsync();
 
-            if (RemainingLength == 0)
+            if (_remainingLength == 0)
             {
                 return;
             }
 
-            var buffer = new byte[RemainingLength];
-            await _source.ReadAsync(buffer);
-
+            var buffer = new byte[_remainingLength];
+            await ReadFromSourceAsync(buffer);
+            
             _remainingData.Write(buffer, 0, buffer.Length);
             _remainingData.Position = 0;
         }
 
-        private async Task ReadFixedHeaderAsync()
-        {
-            FixedHeader = await ReadStreamByteAsync();
-
-            var byteReader = new ByteReader(FixedHeader);
-            byteReader.Read(4);
-            ControlPacketType = (MqttControlPacketType)byteReader.Read(4);
-        }
-
-        private async Task<byte> ReadStreamByteAsync()
-        {
-            var buffer = new byte[1];
-            await _source.ReadAsync(buffer);
-            return buffer[0];
-        }
-
-        private async Task ReadRemainingLengthAsync()
-        {
-            // Alorithm taken from http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html.
-            var multiplier = 1;
-            var value = 0;
-            byte encodedByte;
-            do
-            {
-                encodedByte = await ReadStreamByteAsync();
-                value += (encodedByte & 127) * multiplier;
-                multiplier *= 128;
-                if (multiplier > 128 * 128 * 128)
-                {
-                    throw new MqttProtocolViolationException("Remaining length is ivalid.");
-                }
-            } while ((encodedByte & 128) != 0);
-
-            RemainingLength = value;
-        }
-
         public async Task<byte> ReadRemainingDataByteAsync()
         {
             return (await ReadRemainingDataAsync(1))[0];
@@ -109,7 +73,7 @@ namespace MQTTnet.Core.Serializer
 
         public Task<byte[]> ReadRemainingDataAsync()
         {
-            return ReadRemainingDataAsync(RemainingLength - (int)_remainingData.Position);
+            return ReadRemainingDataAsync(_remainingLength - (int)_remainingData.Position);
         }
 
         public async Task<byte[]> ReadRemainingDataAsync(int length)
@@ -120,6 +84,54 @@ namespace MQTTnet.Core.Serializer
             return buffer;
         }
 
+        private async Task ReadRemainingLengthAsync()
+        {
+            // Alorithm taken from http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html.
+            var multiplier = 1;
+            var value = 0;
+            byte encodedByte;
+            do
+            {
+                encodedByte = await ReadStreamByteAsync();
+                value += (encodedByte & 127) * multiplier;
+                multiplier *= 128;
+                if (multiplier > 128 * 128 * 128)
+                {
+                    throw new MqttProtocolViolationException("Remaining length is ivalid.");
+                }
+            } while ((encodedByte & 128) != 0);
+
+            _remainingLength = value;
+        }
+
+        private Task ReadFromSourceAsync(byte[] buffer)
+        {
+            try
+            {
+                return _source.ReadAsync(buffer);
+            }
+            catch (Exception exception)
+            {
+                throw new MqttCommunicationException(exception);
+            }
+        }
+
+        private async Task<byte> ReadStreamByteAsync()
+        {
+            var buffer = new byte[1];
+            await ReadFromSourceAsync(buffer);
+            return buffer[0];
+        }
+
+        private async Task ReadFixedHeaderAsync()
+        {
+            FixedHeader = await ReadStreamByteAsync();
+
+            var byteReader = new ByteReader(FixedHeader);
+            byteReader.Read(4);
+            ControlPacketType = (MqttControlPacketType)byteReader.Read(4);
+        }
+
         public void Dispose()
         {
             _remainingData?.Dispose();