samer@0: package samer.silk;
samer@0: import java.net.*;
samer@0: import java.io.*;
samer@0: import jsint.*;
samer@0: 
samer@0: /** Terminal to acces a remote JVM.
samer@0: 	Connects to a given port on the remote host,
samer@0: 	then relays System.in and out to the socket.
samer@0:  */
samer@0: 
samer@0: public class Terminal {
samer@0: 
samer@0: 	public static void connect(Socket sock) throws Exception { connect(sock,null); }
samer@0: 	public static void connect(Socket sock, Procedure readline) throws Exception {
samer@0: 		InputStream	in=sock.getInputStream();
samer@0: 		OutputStream	out=sock.getOutputStream();
samer@0: 		Thread	reader=new Thread(new Transfer(in,System.out));
samer@0: 
samer@0: 		reader.start(); // everything coming from socket gets squirted to stdout
samer@0: 
samer@0: 		// this end should be responsible for writing prompt
samer@0: 		if (readline!=null) 	{
samer@0: 			PrintWriter prn=new PrintWriter(out,true);
samer@0: 			try {
samer@0: 				for (;;) {
samer@0: 					prn.println((String)SI.call(readline,"remote> "));
samer@0: 					Thread.sleep(100); // wait for reply
samer@0: 				}
samer@0: 			} catch (Exception ex) {}
samer@0: 		} else (new Transfer(System.in,out)).run();
samer@0: 		System.out.println();
samer@0: 
samer@0: 		sock.shutdownOutput();   // other end should notice this
samer@0: 		reader.join(5000); 		// wait for reader to die, 5 seconds max
samer@0: 		sock.close();
samer@0:   	}
samer@0: 
samer@0: 
samer@0: 	static class Transfer implements Runnable {
samer@0: 		InputStream	in;
samer@0: 		OutputStream	out;
samer@0: 		byte []			buffer;
samer@0: 
samer@0: 		public Transfer(InputStream in, OutputStream out) {
samer@0: 			this.in=in;
samer@0: 			this.out=out;
samer@0: 			buffer=new byte[2048];
samer@0: 		}
samer@0: 
samer@0: 		public void run() {
samer@0: 			int n;
samer@0: 			try {
samer@0: 				do {
samer@0: 					n=in.read(buffer,0,2048);
samer@0: 					if (n>0) { out.write(buffer,0,n); out.flush(); }
samer@0: 				} while (n>=0);
samer@0:     			} catch (Exception ex) { ex.printStackTrace(); }
samer@0: 			System.err.println("reader thread terminating.");
samer@0: 		}
samer@0: 	}
samer@0: 
samer@0: 	public static void REPL(Socket call) throws Exception
samer@0: 	{
samer@0: 		Evaluator evaluator=Scheme.currentEvaluator();
samer@0: 
samer@0: 		PrintWriter	oldout=evaluator.getOutput();
samer@0: 		PrintWriter	olderr=evaluator.getError();
samer@0:  		PrintWriter newout=new PrintWriter(call.getOutputStream(),true);
samer@0: 		InputPort 	newin=new InputPort(new BufferedReader(
samer@0: 			new InputStreamReader(call.getInputStream())));
samer@0: 
samer@0: 
samer@0:  		oldout.println("... starting new remote REPL.");
samer@0:  		newout.println("Welcome to remote JVM - Type Ctrl-D to terminate session.");
samer@0: 
samer@0: 		// would like to replace System.err and System.out
samer@0: 		// with multicast streams
samer@0: 		evaluator.setOutput(newout);
samer@0: 		evaluator.setError(newout);
samer@0: 
samer@0: 		try {
samer@0: 			evaluator.readEvalWriteLoop("remote> ");
samer@0: /* Old version, can't work with jscheme 7.2
samer@0: 			Object x;
samer@0: 			while (!Scheme.EXIT) {
samer@0: 				try {
samer@0: 					newout.print("remote> "); newout.flush();
samer@0: 					if ((x = newin.read()) == InputPort.EOF) break;
samer@0: 					U.write(evaluator.eval(x), newout, true);
samer@0: 					newout.println(); newout.flush();
samer@0: 				} catch (Throwable e) { e.printStackTrace(newout); newout.flush(); }
samer@0: 			}
samer@0: */
samer@0: 			// try to let the other end know that the show's over
samer@0: 			call.shutdownInput();
samer@0: 		}
samer@0: 		finally {
samer@0:  			newout.println("Remote session terminated.");
samer@0: 	 		oldout.println("... remote REPL terminated.");
samer@0: 			evaluator.setOutput(oldout);
samer@0: 			evaluator.setError(olderr);
samer@0: 			evaluator.setExit(false); // remote session not allowed to terminate JVM!
samer@0: 			call.close(); // ?? or shutdownOutput();
samer@0: 		}
samer@0:   	}
samer@0: }