/**
* Function to send a message to the server
* \param stream - The stream to write to
* \param msg - The message to send
* \return - Retun true on success, false on failure
*/
private bool sendMessage(NetworkStream stream, Message msg)
{
string json = JsonConvert.SerializeObject(msg);
using (MemoryStream mstream = new MemoryStream())
{
using (BinaryWriter writer = new BinaryWriter(mstream))
{
byte[] encodedJson = Encoding.UTF8.GetBytes(json);
writer.Write(hostToBig_i32(encodedJson.Length));
writer.Write(encodedJson);
}
byte[] request = mstream.ToArray();
try
{
stream.Write(request, 0, request.Length);
stream.Flush();
}
catch(SocketException ex)
{
Message emsg = new Message("error_socket", null);
emsg.AddParameter("error_code", ex.ErrorCode);
emsg.AddParameter("message", ex.Message);
recvq.Enqueue(emsg);
return false;
}
}
return true;
}
/**
* Function used to handle messages coming from the GUI client
* \param msg - The message to handle
*/
private void dispatchSendMsg(Message msg)
{
switch(msg.Command)
{
case "connect":
// Try to connect to server
Client = new TcpClient();
string host = msg.Arguments["host"].ToString();
int port = Convert.ToInt32(msg.Arguments["port"]);
try
{
Client.Connect(host, port);
}
catch(Exception ex)
{
msg.Command = "connect_failed";
msg.Arguments.Add("message", ex.Message);
recvq.Enqueue(msg);
return;
}
if (Client.Connected)
{
// Store the stream from the TCP client
ClientStream = Client.GetStream();
// Empty the network buffer
recvBuffer.Clear();
// Update the message to a connection response message and send it back to GUI client
msg.Command = "connect_ok";
recvq.Enqueue(msg);
}
else
{
msg.Command = "connect_failed";
msg.Arguments.Add("message", "Connection failed");
recvq.Enqueue(msg);
}
break;
case "disconnect":
// Disconnect from server and send response back to GUI client
if (ClientStream != null)
ClientStream.Close();
ClientStream = null;
if(Client != null && Client.Connected)
Client.Close();
Client = null;
msg.Command = "disconnect_ok";
recvq.Enqueue(msg);
break;
default:
if (ClientStream == null)
{
Message responseMsg = new Message("error", null);
responseMsg.AddParameter("message", "Can not send message, not connected to peer");
recvq.Enqueue(responseMsg);
return;
}
// Send message to server
if(!sendMessage(ClientStream, msg))
{
Message responseMsg = new Message("error", null);
responseMsg.AddParameter("message", "Unable to send message");
recvq.Enqueue(responseMsg);
return;
}
break;
}
}
/**
* Function used to handle messages coming from server
* \param msg - The message to handle
*/
private void dispatchRecvMsg(Message msg)
{
switch (msg.Command)
{
case "close_ok": // The server has received a close message and are closing down
if (ClientStream != null)
ClientStream.Close();
ClientStream = null;
if(Client != null && Client.Connected)
Client.Close();
Client = null;
recvq.Enqueue(msg); // Pass message back to GUI client
break;
default:
recvq.Enqueue(msg); // Pass message back to GUI client
break;
}
}
/**
* Function to read messages out of the network buffer
* \param msg - Storage for any message read from the network buffer
* \return - Return true if a complete message was extracted, false if not
*/
private bool recvMessage(out Message msg)
{
msg = null;
// Make sure buffer hold at least a 32 bit int (netstrings)
if (recvBuffer.Count < 4)
return false;
// Read the message size out of the buffer
byte[] byteSize = new byte[4];
recvBuffer.CopyTo(0, byteSize, 0, 4);
// Convert the size to the hosts endianness
int siz = bigToHost_i32(byteSize);
// Make sure the message stored in the buffer are complete
if (recvBuffer.Count < 4 + siz)
return false;
// Read out the message and update the buffer
byte[] bjson = new byte[siz];
recvBuffer.CopyTo(4, bjson, 0, siz);
recvBuffer.RemoveRange(0, 4 + siz);
// Deserialize the message
string json = Encoding.UTF8.GetString(bjson);
msg = JsonConvert.DeserializeObject<Message>(json);
return true;
}
