/**
* Copyright 2010 JBoss Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.drools.conflict;
import org.drools.reteoo.LeftTuple;
import org.drools.spi.Activation;
import org.drools.spi.ConflictResolver;
/**
* A conflict resolver that compares the total recency of a tuple when
* determining firing order.
*
* @author <a href="mailto:tirelli@post.com">Edson Tirelli</a>
*
* @version $Id: TotalRecencyConflictResolver.java 34350 2010-07-29 22:51:28Z Rikkola $
*/
public class TotalRecencyConflictResolver extends AbstractConflictResolver {
// ----------------------------------------------------------------------
// Class members
// ----------------------------------------------------------------------
/**
*
*/
private static final long serialVersionUID = 510l;
/** Singleton instance. */
private static final TotalRecencyConflictResolver INSTANCE = new TotalRecencyConflictResolver();
// ----------------------------------------------------------------------
// Class methods
// ----------------------------------------------------------------------
/**
* Retrieve the singleton instance.
*
* @return The singleton instance.
*/
public static ConflictResolver getInstance() {
return TotalRecencyConflictResolver.INSTANCE;
}
// ----------------------------------------------------------------------
// Constructors
// ----------------------------------------------------------------------
/**
* Construct.
*/
public TotalRecencyConflictResolver() {
// intentionally left blank
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
/**
* @see ConflictResolver
*/
public int compare(final Activation lhs,
final Activation rhs) {
long leftRecency = 0;
long rightRecency = 0;
// if ( lhs.getTuple() instanceof LeftTuple ) {
// leftRecency = (lhs.getTuple()).getRecency();
// }
// if ( rhs.getTuple() instanceof LeftTuple ) {
// rightRecency = (rhs.getTuple()).getRecency();
// }
return (rightRecency > leftRecency) ? 1 : (rightRecency < leftRecency) ? -1 : 0;
}
}