Sending large objects over TCP: "End of Stream encountered before parsing was completed"
I keep getting an SerializationException
whenever I try to deserialize a list of doubles from a NetworkStream
:
End of Stream encountered before parsing was completed
I have a simple client server architecture: my TcpTransportClient
wraps the functionality of a TcpClient
and I utilize two basic methods: Send
(sends a message) and Receive
(blocks until a message is received).
The Send
function takes a Message
, serializes it using a BinaryFormatter
and sends the bytes via the NetworkStream
.
public void Send(Message message)
{
if (message == null)
{
throw new TransportException("Invalidate Parameter In Send Call");
}
if (_tcpClient == null || !_tcpClient.Connected)
{
throw new TransportException("Client Not Connected");
}
lock (_sync)
{
// Serialzie the message
MemoryStream memStream = new MemoryStream();
_serializer.Serialize(memStream, message);
// Get the bytes of of the memory stream
byte[] buffer = memStream.GetBuffer();
// Write the message to the network stream
NetworkStream networkStream = _tcpClient.GetStream();
networkStream.Write(buffer, 0, buffer.Length);
networkStream.Flush();
}
}
The receive function reads bytes into a buffer from the NetworkStream
, then deserializes the message by using a BinaryFormatter
:
public Message Receive()
{
if (_tcpClient == null || !_tcpClient.Connected)
{
throw new TransportException("Client Not Connected");
}
byte[] buffer;
MemoryStream memStream = new MemoryStream();
NetworkStream netStream = _tcpClient.GetStream();
try
{
do
{
// Allocate a new buffer
buffer = new byte[_tcpClient.ReceiveBufferSize];
// Read the message buffer
int sizeRead = netStream.Read(buffer, 0, buffer.Length);
// Write the buffer to the memory stream
memStream.Write(buffer, 0, sizeRead);
} while (netStream.DataAvailable);
// Reset the memory stream position
memStream.Position = 0;
// Deserialize the message
object tmp = _deserializer.Deserialize(memStream); // <-- The exception is here!
// Cast the object to a message
return (Message)tmp;
}
catch (System.Exception e)
{
if (_tcpClient == null || !_tcpClient.Connected)
{
throw new TransportException("Client Not Connected");
}
else
{
throw e;
}
}
}
I have a basic sending thread:
TcpTransportClient client = new TcpTransportClient(GetLocalAddress(), servicePort);
client.Connect();
Thread sendThread = new Thread(() =>
{
List<double> dataSet = new List<double>();
for (double d = 0.0; d < 500.0; d++)
{
dataSet.Add(d);
}
while (true)
{
try
{
// Serialize the data set
MemoryStream memStream = new MemoryStream();
Binary开发者_运维知识库Formatter binFormat = new BinaryFormatter();
binFormat.Serialize(memStream, (object)dataSet);
// Create a message
Message msg = new Message();
// Hold the object bytes in an opaque field
msg.SetFieldValue(1000, memStream.GetBuffer());
// Set the message topic
msg.SetTopic("client.dataSet");
// Send the message
client.Send(msg);
// Sleep
Thread.Sleep(3000);
}
catch (TransportException)
{
break;
}
catch(Exception)
{
//ignore it
}
}
});
sendThread.IsBackground = true;
sendThread.Start();
And a receive thread which gets started whenever a TcpClient
is accepted:
public void HandleAcceptedClient(TcpTransportClient client)
{
Thread receiveThread = new Thread(() =>
{
while (true)
{
try
{
Message msg = client.Receive();
Trace.WriteLine("Server Received: " + msg.GetTopic());
byte[] buffer = msg.GetFieldOpaqueValue(1000);
MemoryStream memStream = new MemoryStream(buffer);
BinaryFormatter binFormat = new BinaryFormatter();
List<double> dataSet = (List<double>)binFormat.Deserialize(memStream);
if (dataSet.Count == 500)
{
Trace.WriteLine(DateTime.Now + ": OK");
}
else
{
Trace.WriteLine(DateTime.Now + ": FAIL");
}
}
catch (TransportException)
{
break;
}
catch(Exception)
{
// ignore it
}
}
});
receiveThread.IsBackground = true;
receiveThread.Start();
}
The exception always occurs when I try to deserialize the message in Receive
method of my TcpTransportClient
, but the problem only occurs if I put some data in the data set. What's the proper way to send a list of values over a network and successfully deserialize them on the receiving end?
P.S. I tried the solution in a nearly identical question, but it didn't work: I'm still getting the same exception.
while (netStream.DataAvailable);
That's not correct. You should stop reading when the Read() call returns 0. The DataAvailable property just tells you whether or not the Read() call will block, waiting to allow the server to catch up.
You need message framing.
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