/*
* Copyright (C) 2009 eXo Platform SAS.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.exoplatform.services.jcr.impl.xml;
import org.apache.ws.commons.util.Base64;
import org.exoplatform.commons.utils.PrivilegedFileHelper;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
/**
* Created by The eXo Platform SAS.
*
* @author <a href="mailto:Sergey.Kabashnyuk@gmail.com">Sergey Kabashnyuk</a>
* @version $Id: BufferedDecoder.java 11907 2008-03-13 15:36:21Z ksm $
*/
public class BufferedDecoder extends Base64.Decoder
{
/**
* Default buffer size.
*/
private static final int DEFAULT_BUFFER_SIZE = 4096;
/**
*
*/
private static final int DEFAULT_READ_BUFFER_SIZE = 4096;
/**
* Buffer size.
*/
private final int bufferSize;
/**
* Buffer file.
*/
private File fileBuffer;
/**
* Output stream.
*/
private OutputStream out;
/**
* Default constructor.
*/
public BufferedDecoder()
{
super(DEFAULT_BUFFER_SIZE);
this.bufferSize = DEFAULT_BUFFER_SIZE;
this.out = new ByteArrayOutputStream(DEFAULT_BUFFER_SIZE);
}
/**
* @param bufferSize
* - buffer size.
*/
public BufferedDecoder(int bufferSize)
{
super(bufferSize);
this.bufferSize = bufferSize;
this.out = new ByteArrayOutputStream(DEFAULT_BUFFER_SIZE);
}
/**
* @return - input stream.
* @throws IOException
* - unknown output stream.
*/
public InputStream getInputStream() throws IOException
{
flush();
if (out instanceof ByteArrayOutputStream)
{
return new ByteArrayInputStream(((ByteArrayOutputStream)out).toByteArray());
}
else if (out instanceof BufferedOutputStream)
{
out.close();
return new BufferedInputStream(PrivilegedFileHelper.fileInputStream(fileBuffer));
}
else
{
throw new IOException("unexpected change of buffer");
}
}
/**
* Remove buffer.
*
* @throws IOException
* if file cannot be removed.
*/
public void remove() throws IOException
{
if ((fileBuffer != null) && PrivilegedFileHelper.exists(fileBuffer))
{
if (!PrivilegedFileHelper.delete(fileBuffer))
{
throw new IOException("Cannot remove file " + PrivilegedFileHelper.getAbsolutePath(fileBuffer)
+ " Close all streams.");
}
}
}
/**
* @return string representation for buffer
*/
@Override
public String toString()
{
if (out instanceof ByteArrayOutputStream)
{
return ((ByteArrayOutputStream)out).toString();
}
else if (out instanceof BufferedOutputStream)
{
try
{
out.close();
BufferedInputStream is = new BufferedInputStream(PrivilegedFileHelper.fileInputStream(fileBuffer));
StringBuilder fileData = new StringBuilder(DEFAULT_READ_BUFFER_SIZE);
byte[] buf = new byte[bufferSize];
int numRead = 0;
while ((numRead = is.read(buf)) != -1)
{
fileData.append(new String(buf, 0, numRead));
}
is.close();
return fileData.toString();
}
catch (IOException e)
{
return "";
}
}
else
{
return "";
}
}
/**
* Swap in-memory buffer with file.
*
* @exception IOException
* if an I/O error occurs.
*/
private void swapBuffers() throws IOException
{
byte[] data = ((ByteArrayOutputStream)out).toByteArray();
fileBuffer = PrivilegedFileHelper.createTempFile("decoderBuffer", ".tmp");
PrivilegedFileHelper.deleteOnExit(fileBuffer);
out = new BufferedOutputStream(PrivilegedFileHelper.fileOutputStream(fileBuffer), bufferSize);
out.write(data);
}
/**
* Writes <code>length</code> bytes from the specified byte array starting at offset
* <code>start</code> to this byte array output stream.
*
* @param buffer
* the data.
* @param start
* the start offset in the data.
* @param length
* the number of bytes to write.
* @exception IOException
* if an I/O error occurs.
*/
@Override
protected void writeBuffer(byte[] buffer, int start, int length) throws IOException
{
if (out instanceof ByteArrayOutputStream)
{
if (((ByteArrayOutputStream)out).size() + length > bufferSize)
{
swapBuffers();
}
}
out.write(buffer, start, length);
}
}