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 * 
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
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package com.sun.star.lib.connections.pipe;

import java.io.IOException;

import java.util.StringTokenizer;
import java.util.Enumeration;
import java.util.Vector;

import com.sun.star.lib.util.NativeLibraryLoader;

import com.sun.star.io.XStreamListener;

import com.sun.star.connection.XConnection;
import com.sun.star.connection.XConnectionBroadcaster;

/**
 * The PipeConnection implements the <code>XConnection</code> interface
 * and is uses by the <code>PipeConnector</code> and the <code>PipeAcceptor</code>.
 * This class is not part of the provided <code>api</code>.
 * <p>
 * @version 	$Revision: 1.7 $ $ $Date: 2008-04-11 11:13:00 $
 * @author 	    Kay Ramme
 * @see         com.sun.star.comp.connections.PipeAcceptor
 * @see         com.sun.star.comp.connections.PipeConnector
 * @see         com.sun.star.connections.XConnection
 * @since       UDK1.0
 */
public class PipeConnection implements XConnection, XConnectionBroadcaster {
	/**
	 * When set to true, enables various debugging output.
	 */
	static public final boolean DEBUG = false;

    static {
		// load shared library for JNI code
        NativeLibraryLoader.loadLibrary(PipeConnection.class.getClassLoader(), "jpipe");
    }

	protected String	_aDescription;
	protected long		_nPipeHandle;
	protected Vector	_aListeners;
	protected boolean	_bFirstRead;

	/**
	 * Constructs a new <code>PipeConnection</code>.
	 * <p>
	 * @param  description   the description of the connection
	 * @param  pipe        the pipe of the connection
	 */
	public PipeConnection(String description) 
		throws IOException
	{
		if (DEBUG) System.err.println("##### " + getClass().getName() + " - instantiated " + description );

		_aListeners = new Vector();
		_bFirstRead = true;

		// get pipe name from pipe descriptor
		String aPipeName  ;
		StringTokenizer aTokenizer = new StringTokenizer( description, "," );
		if ( aTokenizer.hasMoreTokens() ) 
		{
			String aConnType = aTokenizer.nextToken();
			if ( !aConnType.equals( "pipe" ) )
				throw new RuntimeException( "invalid pipe descriptor: does not start with 'pipe,'" );

			String aPipeNameParam = aTokenizer.nextToken();
			if ( !aPipeNameParam.substring( 0, 5 ).equals( "name=" ) )
				throw new RuntimeException( "invalid pipe descriptor: no 'name=' parameter found" );
			aPipeName = aPipeNameParam.substring( 5 );
     		}
		else
			throw new RuntimeException( "invalid or empty pipe descriptor" );

		// create the pipe
		try 
		{ createJNI( aPipeName ); }
		catch ( java.lang.NullPointerException aNPE )
		{ throw new IOException( aNPE.getMessage() ); }
		catch ( com.sun.star.io.IOException aIOE )
		{ throw new IOException( aIOE.getMessage() ); }
		catch ( java.lang.Exception aE )
		{ throw new IOException( aE.getMessage() ); }
	}

	public void addStreamListener(XStreamListener aListener ) throws com.sun.star.uno.RuntimeException {
		_aListeners.addElement(aListener);
	}

	public void removeStreamListener(XStreamListener aListener ) throws com.sun.star.uno.RuntimeException {
		_aListeners.removeElement(aListener);
	}

	private void notifyListeners_open() {
		Enumeration elements = _aListeners.elements();
		while(elements.hasMoreElements()) {
			XStreamListener xStreamListener = (XStreamListener)elements.nextElement();
			xStreamListener.started();
		}
	}

	private void notifyListeners_close() {
		Enumeration elements = _aListeners.elements();
		while(elements.hasMoreElements()) {
			XStreamListener xStreamListener = (XStreamListener)elements.nextElement();
			xStreamListener.closed();
		}
	}
	
	private void notifyListeners_error(com.sun.star.uno.Exception exception) {
		Enumeration elements = _aListeners.elements();
		while(elements.hasMoreElements()) {
			XStreamListener xStreamListener = (XStreamListener)elements.nextElement();
			xStreamListener.error(exception);
		}
	}

	// JNI implementation to create the pipe
	private native int createJNI( String name )
		throws com.sun.star.io.IOException, com.sun.star.uno.RuntimeException;
	
	// JNI implementation to read from the pipe
	private native int readJNI(/*OUT*/byte[][] bytes, int nBytesToRead) 
		throws com.sun.star.io.IOException, com.sun.star.uno.RuntimeException;
	
	// JNI implementation to write to the pipe
	private native void writeJNI(byte aData[]) 
		throws com.sun.star.io.IOException, com.sun.star.uno.RuntimeException;
	
	// JNI implementation to flush the pipe
	private native void flushJNI() 
		throws com.sun.star.io.IOException, com.sun.star.uno.RuntimeException;

	// JNI implementation to close the pipe
	private native void closeJNI() 
		throws com.sun.star.io.IOException, com.sun.star.uno.RuntimeException;

	/**
	 * Read the required number of bytes.
	 * <p>
	 * @return   the number of bytes read
	 * @param    aReadBytes   the outparameter, where the bytes have to be placed
	 * @param    nBytesToRead the number of bytes to read
	 * @see       com.sun.star.connections.XConnection#read
	 */
	public int read(/*OUT*/byte[][] bytes, int nBytesToRead) 
		throws com.sun.star.io.IOException, com.sun.star.uno.RuntimeException 
	{
		if(_bFirstRead) {
			_bFirstRead = false;

			notifyListeners_open();
		}

		return readJNI( bytes, nBytesToRead );
	}

	/**
	 * Write bytes.
	 * <p>
	 * @param    aData the bytes to write
	 * @see       com.sun.star.connections.XConnection#write
	 */
	public void write(byte aData[]) 
		throws com.sun.star.io.IOException, com.sun.star.uno.RuntimeException 
	{
		writeJNI( aData );
	}

	/**
	 * Flushes the buffer.
	 * <p>
	 * @see       com.sun.star.connections.XConnection#flush
	 */
	public void flush() 
		throws com.sun.star.io.IOException, com.sun.star.uno.RuntimeException 
	{
		flushJNI();
	}

	/**
	 * Closes the connection.
	 * <p>
	 * @see       com.sun.star.connections.XConnection#close
	 */
	public void close() 
		throws com.sun.star.io.IOException, com.sun.star.uno.RuntimeException 
	{
		if (DEBUG) System.out.print( "PipeConnection::close() " );
		closeJNI();
		notifyListeners_close();
		if (DEBUG) System.out.println( "done" );
	}

	/**
	 * Gives a description of the connection.
	 * <p>
	 * @return  the description
 	 * @see       com.sun.star.connections.XConnection#getDescription
	 */
	public String getDescription() throws com.sun.star.uno.RuntimeException {
		return _aDescription;
	}

}