private bool AttemptConnection(int pipe)
{
if (IsConnected)
{
Logger.Error("Cannot connect as the pipe is already connected");
throw new Exception("Cannot connect as the pipe is already connected");
}
//Prepare the pipe name
string pipename = string.Format(PIPE_NAME, pipe);
Logger.Info("Attempting to connect to " + pipename);
uint err = NativePipeExtern.Open(pipename);
if (err == 0 && IsConnected)
{
Logger.Info("Succesfully connected to " + pipename);
_connectedPipe = pipe;
return(true);
}
else
{
Logger.Error("Failed to connect to native pipe. Err: {0}", err);
return(false);
}
}
/// <summary>
/// Attempts to write a frame
/// </summary>
/// <param name="frame"></param>
/// <returns></returns>
public bool WriteFrame(PipeFrame frame)
{
if (!IsConnected)
{
throw new Exception("Cannot write Native Stream as pipe is not connected");
}
//Create a memory stream so we can write it to the pipe
using (MemoryStream stream = new MemoryStream())
{
//Write the stream and the send it to the pipe
frame.WriteStream(stream);
//Get the bytes and send it
byte[] bytes = stream.ToArray();
//Copy the bytes into a new marshaled block
int size = Marshal.SizeOf(bytes[0]) * bytes.Length;
IntPtr pnt = Marshal.AllocHGlobal(size);
try
{
//Send the marshaled block
Marshal.Copy(bytes, 0, pnt, bytes.Length);
return(NativePipeExtern.WriteFrame(pnt, bytes.Length));
}
finally
{
//Finally, before exiting the try catch, free the memory we assigned.
Marshal.FreeHGlobal(pnt);
}
}
}
/// <summary>
/// Closes the pipe
/// </summary>
public void Close()
{
NativePipeExtern.Close();
}
/// <summary>
/// Attempts to read a frame
/// </summary>
/// <param name="frame"></param>
/// <returns></returns>
public bool ReadFrame(out PipeFrame frame)
{
//Make sure we are connected
if (!IsConnected)
{
throw new Exception("Cannot read Native Stream as pipe is not connected");
}
//Prepare bytes read and a buffer of memory to read into
int bytesRead = 0;
int size = Marshal.SizeOf(_buffer[0]) * _buffer.Length;
IntPtr pnt = Marshal.AllocHGlobal(size);
//Try and read the frame from the native pipe
try
{
bytesRead = NativePipeExtern.ReadFrame(pnt, _buffer.Length);
if (bytesRead <= 0)
{
//We have not read a valid amount of bytes, so return a error message.
//Update the error message
_lasterr = NativePipeExtern.PipeReadError.ReadEmptyMessage;
//A error actively occured. If it is 0 we just read no bytes.
if (bytesRead < 0)
{
//We have a pretty bad error, we will log it for prosperity.
_lasterr = (NativePipeExtern.PipeReadError)bytesRead;
Logger.Error("Native pipe failed to read: {0}", _lasterr.ToString());
//Close this pipe
this.Close();
}
//Return a empty frame and return false (read failure).
frame = default(PipeFrame);
return(false);
}
else
{
//WE have read a valid amount of bytes, so copy the marshaled bytes over to the buffer
Marshal.Copy(pnt, _buffer, 0, bytesRead);
}
}
finally
{
//Finally, before we exit this try block, free the pointer we allocated.
Marshal.FreeHGlobal(pnt);
}
//Parse the message by reading the contents into a memory stream.
using (MemoryStream stream = new MemoryStream(_buffer, 0, bytesRead))
{
//Try to parse the stream
frame = new PipeFrame();
if (frame.ReadStream(stream) && frame.Length != 0)
{
return(true);
}
//We failed
Logger.Error("Pipe failed to read from the data received by the stream.");
return(false);
}
}
