Remove not async task handling.

Source/MQTTnet/Formatter/MqttPacketReader.cs

@@ -21,8 +21,6 @@ namespace MQTTnet.Formatter
         {
             // The MQTT fixed header contains 1 byte of flags and at least 1 byte for the remaining data length.
             // So in all cases at least 2 bytes must be read for a complete MQTT packet.
-            // async/await is used here because the next packet is received in a couple of minutes so the performance
-            // impact is acceptable according to a useless waiting thread.
             var buffer = fixedHeaderBuffer;
             var totalBytesRead = 0;
 
@@ -55,16 +53,7 @@ namespace MQTTnet.Formatter
                 };
             }
 
-#if WINDOWS_UWP
-            // UWP will have a dead lock when calling this not async.
             var bodyLength = await ReadBodyLengthAsync(buffer[1], cancellationToken).ConfigureAwait(false);
-#else
-            // Here the async/await pattern is not used because the overhead of context switches
-            // is too big for reading 1 byte in a row. We expect that the remaining data was sent
-            // directly after the initial bytes. If the client disconnects just in this moment we
-            // will get an exception anyway.
-            var bodyLength = ReadBodyLength(buffer[1], cancellationToken);
-#endif
 
             if (!bodyLength.HasValue)
             {
@@ -81,49 +70,6 @@ namespace MQTTnet.Formatter
             };
         }
 
-#if !WINDOWS_UWP
-        private int? ReadBodyLength(byte initialEncodedByte, CancellationToken cancellationToken)
-        {
-            var offset = 0;
-            var multiplier = 128;
-            var value = initialEncodedByte & 127;
-            int encodedByte = initialEncodedByte;
-
-            while ((encodedByte & 128) != 0)
-            {
-                offset++;
-                if (offset > 3)
-                {
-                    throw new MqttProtocolViolationException("Remaining length is invalid.");
-                }
-
-                if (cancellationToken.IsCancellationRequested)
-                {
-                    return null;
-                }
-
-                var readCount = _channel.ReadAsync(_singleByteBuffer, 0, 1, cancellationToken).GetAwaiter().GetResult();
-
-                if (cancellationToken.IsCancellationRequested)
-                {
-                    return null;
-                }
-
-                if (readCount == 0)
-                {
-                    return null;
-                }
-
-                encodedByte = _singleByteBuffer[0];
-
-                value += (encodedByte & 127) * multiplier;
-                multiplier *= 128;
-            }
-
-            return value;
-        }
-#else
-
         private async Task<int?> ReadBodyLengthAsync(byte initialEncodedByte, CancellationToken cancellationToken)
         {
             var offset = 0;
@@ -164,6 +110,5 @@ namespace MQTTnet.Formatter
 
             return value;
         }
-#endif
     }
 }