/*
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 Sep 15, 2008
*/
package com.bigdata.btree.keys;
/**
* Delegation pattern for {@link ISortKeyBuilder} that is useful when you need
* to {@link #resolve(Object)} one type to another before applying the delegate
* to generate the sort key.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
* @param <E>
* The generic type of the object to which this builder will be
* applied.
* @param <F>
* The generic type of the object whose sort keys the delegate can
* generate.
*/
abstract public class DelegateSortKeyBuilder<E, F> implements
ISortKeyBuilder<E> {
private final ISortKeyBuilder<F> delegate;
public DelegateSortKeyBuilder(final ISortKeyBuilder<F> delegate) {
if (delegate == null)
throw new IllegalArgumentException();
this.delegate = delegate;
}
/**
* Resolve one generic type to another.
*
* @param e
* An element.
*
* @return The resolved element.
*/
abstract protected F resolve(E e);
public byte[] getSortKey(E e) {
return delegate.getSortKey(resolve(e));
}
}