/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * 
 * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
 * 
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License. You can obtain
 * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
 * or glassfish/bootstrap/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 * 
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
 * Sun designates this particular file as subject to the "Classpath" exception
 * as provided by Sun in the GPL Version 2 section of the License file that
 * accompanied this code.  If applicable, add the following below the License
 * Header, with the fields enclosed by brackets [] replaced by your own
 * identifying information: "Portions Copyrighted [year]
 * [name of copyright owner]"
 * 
 * Contributor(s):
 * 
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
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 */
 
/*
 * $Header: /cvs/glassfish/admin/mbeanapi-impl/src/java/com/sun/enterprise/management/support/DownloadInfo.java,v 1.5 2007/05/05 05:23:41 tcfujii Exp $
 * $Revision: 1.5 $
 * $Date: 2007/05/05 05:23:41 $
 */
package com.sun.enterprise.management.support;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;


public final class DownloadInfo extends UpDownInfo
{
	private FileInputStream	mInputStream;
	
	private long			mReadSoFar;
	private final long		mTotalSize;
	private final boolean	mDeleteWhenDone;
	
		public
	DownloadInfo(
		final Object	id,
		final File		theFile,
		final boolean	deleteWhenDone )
		throws IOException
	{
		super( id, theFile );
		
		mTotalSize		= theFile.length();
		if ( theFile.length() == 0 )
		{
			throw new IllegalArgumentException( theFile.toString() );
		}
		
		mReadSoFar		= 0;
		mDeleteWhenDone	= deleteWhenDone;
		
		if ( mDeleteWhenDone )
		{
			theFile.deleteOnExit();
		}
		
		mInputStream	= new FileInputStream( theFile );
		
		assert( ! isDone() );
	}
	
	
		public final long
	getLength()
	{
		return( mTotalSize );
	}
	
		private final long
	getRemaining()
	{
		return( mTotalSize - mReadSoFar );
	}
	
		public boolean
	isDone()
	{
		return( mReadSoFar == mTotalSize );
	}
	
	
	/**
		@return true if done, false otherwise
	 */
		public synchronized byte[]
	read( final int requestSize )
		throws IOException
	{
		if ( isDone() )
		{
			throw new IllegalArgumentException( "operation has been completed" );
		}
		
		final long	remaining	= getRemaining();
		
		byte[]		bytes	= null;
		if ( remaining != 0 )
		{
			final long	actual		= remaining < requestSize ? remaining : requestSize;
			
			bytes	= new byte[ (int)actual ];
			final int	numRead	= mInputStream.read( bytes );
			if ( numRead != bytes.length )
			{
				throw new IOException();
			}
			
			mReadSoFar	+= numRead;
			
			if ( isDone() )
			{
				cleanup();
			}
			
			accessed();
		}
		
		return( bytes );
	}
	
		public synchronized void
	cleanup()
		throws IOException
	{
		if ( mInputStream != null )
		{
			mInputStream.close();
			mInputStream	= null;
		}
		
		if ( mDeleteWhenDone )
		{
			getFile().delete();
		}
	}
}