/*
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 Apr 15, 2009
*/
package com.bigdata.service.ndx.pipeline;
import com.bigdata.btree.keys.KVO;
/**
* Interface allowing application specific elimination of duplicates.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*/
public interface IDuplicateRemover<O> {
/**
* Accepts a dense array of key-value tuples and returns a dense array of
* key-value tuples in which duplicates have been eliminated. The elements
* of the given array MUST NOT be modified as a side-effect.
* <p>
* Implementations MUST be thread-safe.
* <p>
* Implementations MUST test for {@link KVOList} and obey its contract (this
* ensures that we can map {@link KVO#done()} over the eliminated duplicates
* once the original has been written successfully onto the database).
*
* @param a
* A sorted array of key-value tuples.
*
* @return The a dense array of key-value tuples in which any duplicates
* have been eliminated.
*
* @todo The thread safe requirement is probably not necessary. At least as
* implemented, duplicates are eliminated by the
* {@link IndexPartitionWriteTask} within a single-threaded context.
*/
public KVO<O>[] filter(KVO<O>[] a);
}