/*
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 Nov 17, 2008
*/
package com.bigdata.service.proxy;
import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.rmi.Remote;
import java.util.concurrent.TimeUnit;
import com.bigdata.io.IStreamSerializer;
import com.bigdata.relation.accesspath.IAsynchronousIterator;
/**
* A helper object that provides the API of {@link IAsynchronousIterator} but
* whose methods throw {@link IOException} and are therefore compatible with
* {@link Remote} and {@link Exporter}.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
* @param <T>
*/
public class RemoteAsynchronousIteratorImpl<E> implements
RemoteAsynchronousIterator<E> {
private final IAsynchronousIterator<E> itr;
private final IStreamSerializer<E> serializer;
/**
* Ctor variant does not support {@link #nextElement()}.
*
* @param itr
* The source iterator (local object).
*/
public RemoteAsynchronousIteratorImpl(final IAsynchronousIterator<E> itr) {
this(itr, null/* serializer */);
}
/**
* Ctor variant optionally supports {@link #nextElement()}.
*
* @param itr
* The source iterator (local object).
* @param serializer
* Optional, but {@link #nextElement()} only works when you
* specify an {@link IStreamSerializer}.
*/
public RemoteAsynchronousIteratorImpl(
final IAsynchronousIterator<E> itr,
final IStreamSerializer<E> serializer
) {
if (itr == null)
throw new IllegalArgumentException();
// if (serializer == null)
// throw new IllegalArgumentException();
this.itr = itr;
this.serializer = serializer;
}
public void close() throws IOException {
itr.close();
}
public boolean hasNext() throws IOException {
return itr.hasNext();
}
public boolean hasNext(long timeout, TimeUnit unit) throws IOException,
InterruptedException {
return itr.hasNext(timeout, unit);
}
public boolean isExhausted() throws IOException {
return itr.isExhausted();
}
public E next() throws IOException {
return itr.next();
}
public E next(long timeout, TimeUnit unit) throws IOException,
InterruptedException {
return itr.next(timeout, unit);
}
public void remove() throws IOException {
itr.remove();
}
/**
* @throws UnsupportedOperationException
* if you did not specify an {@link IStreamSerializer} to the ctor.
*/
public RemoteElement<E> nextElement() {
if (serializer == null)
throw new UnsupportedOperationException();
final E e = itr.next();
return new RemoteElementImpl<E>(e, serializer);
}
/**
* {@link RemoteElement} impl.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
* @param <E>
*/
private static class RemoteElementImpl<E> implements RemoteElement<E>,
Externalizable {
/**
*
*/
private static final long serialVersionUID = -167351084165715123L;
private transient E e;
private transient IStreamSerializer<E> ser;
/**
* De-serialization ctor.
*/
public RemoteElementImpl() {
}
public RemoteElementImpl(final E e, final IStreamSerializer<E> ser) {
if (e == null)
throw new IllegalArgumentException();
if (ser == null)
throw new IllegalArgumentException();
this.e = e;
this.ser = ser;
}
public E get() {
return e;
}
/**
* The initial version.
*/
private static final transient byte VERSION0 = 0;
/**
* The current version.
*/
private static final transient byte VERSION = VERSION0;
public void readExternal(ObjectInput in) throws IOException,
ClassNotFoundException {
final byte version = in.readByte();
switch (version) {
case VERSION0:
break;
default:
throw new UnsupportedOperationException("Unknown version: "
+ version);
}
ser = (IStreamSerializer<E>) in.readObject();
e = ser.deserialize(in);
}
public void writeExternal(ObjectOutput out) throws IOException {
out.writeByte(VERSION);
out.writeObject(ser);
ser.serialize(out, e);
}
}
}