bundles/org.eclipse.team.cvs.core/src/org/eclipse/team/internal/ccvs/core/connection/ExtConnection.java

package org.eclipse.team.internal.ccvs.core.connection;

/*
 * (c) Copyright IBM Corp. 2000, 2001.
 * All Rights Reserved.
 */

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.team.internal.ccvs.core.CVSProviderPlugin;
import org.eclipse.team.internal.ccvs.core.ICVSRepositoryLocation;
import org.eclipse.team.internal.ccvs.core.IServerConnection;
import org.eclipse.team.internal.ccvs.core.Policy;
import org.eclipse.team.internal.core.streams.PollingInputStream;
import org.eclipse.team.internal.core.streams.PollingOutputStream;
import org.eclipse.team.internal.core.streams.TimeoutInputStream;
import org.eclipse.team.internal.core.streams.TimeoutOutputStream;

/**
 * Implements a connection method which invokes an external tool to 
 * establish the connection to the cvs server. Authentication and starting
 * of the cvs server are the responsibility of the external connection
 * tool.
 */
public class ExtConnection implements IServerConnection {

	// command to start remote cvs in server mode
	private static final String INVOKE_SVR_CMD = "server"; //$NON-NLS-1$
	
	// The default port for rsh
	private static final int DEFAULT_PORT = 9999;

	// cvs format for the repository (e.g. :extssh:user@host:/home/cvs/repo)
	private ICVSRepositoryLocation location;

	// incoming from remote host
	InputStream inputStream;

	// outgoing to remote host
	OutputStream outputStream;
	
	// Process spawn to run the command
	Process process;
	
	protected ExtConnection(ICVSRepositoryLocation location, String password) {
		this.location = location;
		// passwork not needed, authentication performed by external tool
	}
	
	/**
	 * Closes the connection.
	 */
	public void close() throws IOException {
		try {
			if (inputStream != null) inputStream.close();
		} finally {
			inputStream = null;
			try {
				if (outputStream != null) outputStream.close();
			} finally {
				outputStream = null;
				process.destroy();
			}
		}
	}
	
	/**
	 * Returns the <code>InputStream</code> used to read data from the
	 * server.
	 */
	public InputStream getInputStream() {
		return inputStream;
	}
	
	/**
	 * Returns the <code>OutputStream</code> used to send data to the
	 * server.
	 */
	public OutputStream getOutputStream() {
		return outputStream;
	}
	
	/**
	 * Opens the connection and invokes cvs in server mode.
	 *
	 * @see Connection.open()
	 */
	public void open(IProgressMonitor monitor) throws IOException {
		String hostname = location.getHost();
		String username = location.getUsername();
		
		String CVS_RSH = CVSProviderPlugin.getPlugin().getCvsRshCommand();
		String CVS_SERVER = CVSProviderPlugin.getPlugin().getCvsServer();
		String[] command = new String[] {CVS_RSH, hostname, "-l", username, CVS_SERVER, INVOKE_SVR_CMD}; //$NON-NLS-1$
		
		int port = location.getPort();
		if (port == location.USE_DEFAULT_PORT)
			port = DEFAULT_PORT;
			
		// The command line doesn't support the use of a port
		if (port != DEFAULT_PORT)
			throw new IOException(Policy.bind("EXTServerConnection.invalidPort")); //$NON-NLS-1$
				
		if(CVS_RSH == null || CVS_SERVER == null) {
			throw new IOException(Policy.bind("EXTServerConnection.varsNotSet"));				 //$NON-NLS-1$
		}

		boolean connected = false;
		try {
			process = Runtime.getRuntime().exec(command);

			inputStream = new PollingInputStream(new TimeoutInputStream(process.getInputStream(),
				8192 /*bufferSize*/, 1000 /*readTimeout*/, -1 /*closeTimeout*/), location.getTimeout(), monitor);
			outputStream = new PollingOutputStream(new TimeoutOutputStream(process.getOutputStream(),
				8192 /*buffersize*/, 1000 /*writeTimeout*/, 1000 /*closeTimeout*/), location.getTimeout(), monitor);

			// XXX need to do something more useful with stderr
			// discard the input to prevent the process from hanging due to a full pipe
			Thread thread = new DiscardInputThread(process.getErrorStream());
			connected = true;
		} finally {
			if (! connected) {
				try {
					close();
				} finally {
					throw new IOException(Policy.bind("EXTServerConnection.ioError", CVS_RSH)); //$NON-NLS-1$
				}
			}
		}
	}
	
	private static class DiscardInputThread extends Thread {
		private InputStream in;
		public DiscardInputThread(InputStream in) {
			this.in = in;
		}
		public void run() {
			try {
				try {
					while (in.read() != -1);
				} finally {
					in.close();
				}
			} catch (IOException e) {
			}
		}
	}
}