/*
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Oct 28, 2008
*/
package com.bigdata.relation.accesspath;
import java.util.NoSuchElementException;
import java.util.concurrent.TimeUnit;
import com.bigdata.striterator.IChunkedIterator;
import cutthecrap.utils.striterators.ICloseableIterator;
/**
* An {@link IAsynchronousIterator} that wraps an {@link IChunkedIterator} or a
* {@link ICloseableIterator}.
*
* @param E
* The generic type of the visited chunks.
* @param F
* The generic type of the source elements.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id: ThickAsynchronousIterator.java 2265 2009-10-26 12:51:06Z
* thompsonbry $
*/
public class WrappedAsynchronousIterator<E,F> implements IAsynchronousIterator<E> {
// private static final Logger log = Logger.getLogger(WrappedAsynchronousIterator.class);
private transient volatile boolean open = true;
private final IChunkedIterator<F> src;
/**
*
* @param src
* The source.
*
* @throws IllegalArgumentException
* if <i>src</i> is <code>null</code>.
*/
public WrappedAsynchronousIterator(final IChunkedIterator<F> src) {
if (src == null)
throw new IllegalArgumentException();
this.src = src;
}
// private final void assertOpen() {
//
// if (!open)
// throw new IllegalStateException();
//
// }
public boolean hasNext() {
if(open && src.hasNext())
return true;
/*
* Explicit close so we close the source as well when this is exhausted.
*
* @see https://sourceforge.net/apps/trac/bigdata/ticket/361
*/
close();
return false;
}
@SuppressWarnings("unchecked")
public E next() {
if (!hasNext())
throw new NoSuchElementException();
return (E) src.nextChunk();
}
public void remove() {
src.remove();
}
/*
* ICloseableIterator.
*/
public void close() {
if (open) {
open = false;
src.close();
}
}
/*
* IAsynchronousIterator.
*/
public boolean isExhausted() {
return !hasNext();
}
/**
* Delegates to {@link #hasNext()} since all data are local and timeouts can
* not occur.
*/
public boolean hasNext(long timeout, TimeUnit unit) {
return hasNext();
}
/**
* Delegates to {@link #next()} since all data are local and timeouts can
* not occur.
*/
public E next(long timeout, TimeUnit unit) {
return next();
}
}