/**
* Creates a new CNSService
*
* @param cnsNode
* The NodeID of the Node with the CNS on it
* @//throws JCSPNetworkException
* Thrown if something goes wrong in the underlying architecture
*/
public CNSService(NodeID cnsNode)
// //throws JCSPNetworkException
{
// Create the input and output channel
this.toCNS = NetChannel.one2net(new NetChannelLocation(cnsNode, 1), new CNSNetworkMessageFilter.FilterTX());
this.fromCNS = NetChannel.net2one(new CNSNetworkMessageFilter.FilterRX());
// We now need to logon to the CNS
CNSMessage message = new CNSMessage();
message.type = CNSMessageProtocol.LOGON_MESSAGE;
message.location1 = (NetChannelLocation)this.fromCNS.getLocation();
this.toCNS.write(message);
// Wait for logon reply message
CNSMessage logonReply = (CNSMessage)this.fromCNS.read();
// Check if we logged on OK
if (logonReply.success == false)
{
Node.err.log(this.GetType(), "Failed to logon to CNS");
throw new JCSPNetworkException("Failed to Logon to CNS");
}
Node.log.log(this.GetType(), "Logged into CNS");
}
/**
* Resolves a name on the CNS, retrieving the NetChannelLocation for the channel
*
* @param name
* The name to resolve
* @return The NetChannelLocation of the channel declared name
* @//throws JCSPNetworkException
* Thrown if something goes wrong in the underlying architecture
*/
public NetChannelLocation resolve(String name)
////throws JCSPNetworkException
{
// Create a temporary channel to receive the incoming NetChannelLocation
NetChannelInput In = NetChannel.net2one(new CNSNetworkMessageFilter.FilterRX());
// Create a resolution message
CNSMessage message = new CNSMessage();
message.type = CNSMessageProtocol.RESOLVE_REQUEST;
message.location1 = (NetChannelLocation)In.getLocation();
message.name = name;
// Write the resolution message to the CNS
this.toCNS.write(message);
// Read in reply
CNSMessage reply = (CNSMessage)In.read();
// Destroy the temporary channel
In.destroy();
// Now return the resolved location, or throw an exception
if (reply.success == true)
{
return(reply.location1);
}
throw new JCSPNetworkException("Failed to resolve channel named: " + name);
}
/**
* Decodes the byte equivalent of a CNSMessage
*
* @param bytes
* The byte equivalent of a CNSMessage
* @return The recreated CNSMessage
* @//throws IOException
* Thrown if something goes wrong during the recreation
*/
public Object filterRX(byte[] bytes)
////throws IOException
{
this.byteIn = new MemoryStream(bytes);
this.dis = new BinaryReader(byteIn);
// Recreate the message
CNSMessage msg = new CNSMessage();
msg.type = this.dis.ReadByte();
msg.success = this.dis.ReadBoolean();
msg.location1 = NetChannelLocation.parse(this.dis.ReadString());
msg.location2 = NetChannelLocation.parse(this.dis.ReadString());
msg.name = this.dis.ReadString();
return(msg);
}
/**
* Registers an input end with the CNS
*
* @param name
* The name to register the channel with
* @param in
* The NetChannelInput to register with the CNS
* @return True if the channel was successfully registered, false otherwise
*/
public Boolean register(String name, NetChannelInput In)
{
// Ensure that only one registration can happen at a time
lock (this)
{
// Create a new registration message
CNSMessage message = new CNSMessage();
message.type = CNSMessageProtocol.REGISTER_REQUEST;
message.name = name;
message.location1 = (NetChannelLocation)this.fromCNS.getLocation();
message.location2 = (NetChannelLocation)In.getLocation();
// Write registration message to the CNS
this.toCNS.write(message);
// Read in reply
CNSMessage reply = (CNSMessage)this.fromCNS.read();
return(reply.success);
}
}
/**
* Converts an object (a CNSMessage) into bytes
*
* @param obj
* The CNSMessage to convert
* @return The byte equivalent of the CNSMessage
* @//throws IOException
* Thrown if something goes wrong during the conversion
*/
public byte[] filterTX(Object obj)
////throws IOException
{
// First ensure we have a CNSMessage
if (!(obj is CNSMessage))
{
throw new IOException("Attempted to send a non CNSMessage on a CNSMessage channel");
}
CNSMessage msg = (CNSMessage)obj;
// Now reset the byte stream
//this.baos.reset();
this.baos.Dispose();
// Write the parts of the CNSMessage to the stream
this.dos.Write(msg.type);
this.dos.Write(msg.success);
if (msg.location1 != null)
{
this.dos.Write(msg.location1.ToString());
}
else
{
this.dos.Write("null");
}
if (msg.location2 != null)
{
this.dos.Write(msg.location2.ToString());
}
else
{
this.dos.Write("null");
}
this.dos.Write(msg.name);
// Flush the stream
this.dos.Flush();
// Get the bytes
return(this.baos.ToArray());
}
