svninputstream.java

linux subdivision ying gai ke yi le ba

/**
 * @copyright
 * ====================================================================
 * Copyright (c) 2003 CollabNet.  All rights reserved.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution.  The terms
 * are also available at http://subversion.tigris.org/license-1.html.
 * If newer versions of this license are posted there, you may use a
 * newer version instead, at your option.
 *
 * This software consists of voluntary contributions made by many
 * individuals.  For exact contribution history, see the revision
 * history and logs, available at http://subversion.tigris.org/.
 * ====================================================================
 * @endcopyright
 */
package org.tigris.subversion.javahl;

import java.io.IOException;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;
/**
 * This class connects a java.io.PipedInputStream to a OutputInterface.
 * The outherside of the Pipe must read by another thread, or deadlocks
 * will occure
 */
public class SVNInputStream extends PipedInputStream
{
    /**
     * my connection to put data into subversion
     */
    Outputer myOutputer;
    /**
     * Creates a SVNInputStream so that it is connected with an internal
     * PipedOutputStream
     * @throws IOException
     */
    public SVNInputStream() throws IOException
    {
        myOutputer = new Outputer(this);
    }
    /**
     * Get the Interface to connect to SVNAdmin
     * @return the connetion interface
     */
    public OutputInterface getOutputer()
    {
        return myOutputer;
    }
    /**
     * Closes this input stream and releases any system resources associated
     * with the stream.
     *
     * <p> The <code>close</code> method of <code>InputStream</code> does
     * nothing.
     *
     * @exception  IOException  if an I/O error occurs.
     */
    public void close() throws IOException
    {
        myOutputer.closed = true;
        super.close();
    }

    /**
     * this class implements the connection to SVNAdmin
     */
    public class Outputer implements OutputInterface
    {
        /**
         * my side of the pipe
         */
        PipedOutputStream myStream;
        /**
         * flag that the other side of the pipe has been closed
         */
        boolean closed;
        /**
         * build a new connection object
         * @param myMaster  the other side of the pipe
         * @throws IOException
         */
        Outputer(SVNInputStream myMaster) throws IOException
        {
            myStream =new PipedOutputStream(myMaster);
        }
        /**
         * write the bytes in data to java
         * @param data          the data to be writtem
         * @throws IOException  throw in case of problems.
         */
        public int write(byte[] data) throws IOException
        {
            if(closed)
                throw new IOException("stream has been closed");
            myStream.write(data);
            return data.length;
        }

        /**
         * close the output
         * @throws IOException throw in case of problems.
         */
        public void close() throws IOException
        {
            myStream.close();
        }
    }
}