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Throw MqttCommunicationException if access to underlying source failed.

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This commit is contained in:
Christian Kratky
2017-05-06 12:15:57 +02:00
parent 86dddd81c7
commit 93a3bbd849
1 changed files with 55 additions and 43 deletions
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MQTTnet.Core/Serializer/MqttPacketReader.cs
+55 -43
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@@ -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();