/// <summary>
/// Asynchronously read a complete packet from a possibly-fragmented stream
/// </summary>
public IAsyncResult BeginReadFromStream(Stream stream, AsyncCallback asyncCallback, object asyncState)
{
ReadFromStreamAsyncResult internalState = new ReadFromStreamAsyncResult(
stream,
this,
asyncCallback,
asyncState);
this.InternalBeginReadFromStream(
stream,
SsmPacketParser.ReadCompleted,
internalState);
return(internalState);
}
/// <summary>
/// Returns the new packet to the caller
/// </summary>
public SsmPacket EndReadFromStream(IAsyncResult asyncResult)
{
ReadFromStreamAsyncResult internalState = (ReadFromStreamAsyncResult)asyncResult;
try
{
if (internalState.Exception != null)
{
throw internalState.Exception;
}
return(SsmPacket.ParseResponse(this.buffer, 0, this.bytesReceived));
}
finally
{
internalState.Dispose();
}
}
/// <summary>
/// Invoked each time stream.BeginRead completes
/// </summary>
/// <remarks>
/// Parse the received bytes, notify the consumer if a full packet is
/// received or if anything goes wrong.
/// </remarks>
private static void ReadCompleted(IAsyncResult asyncResult)
{
ReadFromStreamAsyncResult internalState = (ReadFromStreamAsyncResult)asyncResult.AsyncState;
try
{
SsmPacketParser parser = internalState.Parser;
int offset = parser.bytesReceived;
int bytesReceived = internalState.Stream.EndRead(asyncResult);
for (int i = 0; i < bytesReceived; i++)
{
int index = offset + i;
internalState.Parser.CheckByte(index, internalState.Parser.buffer[index]);
parser.bytesReceived++;
}
if (internalState.Parser.IsComplete)
{
internalState.Completed();
}
else
{
internalState.Parser.InternalBeginReadFromStream(
internalState.Stream,
SsmPacketParser.ReadCompleted,
internalState);
}
}
catch (System.Security.SecurityException ex)
{
internalState.Exception = ex;
internalState.Completed();
}
catch (IOException ex)
{
internalState.Exception = ex;
internalState.Completed();
}
}
