/*
* Copyright (c) 2012 Alexander Diener,
*
* 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, either version 3 of the License, or (at your option) any later
* version.
*
* 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, see <http://www.gnu.org/licenses/>.
*/
package de.fhkn.in.uce.connectivitymanager.selector.weighting;
import java.io.Serializable;
import java.util.Comparator;
import net.jcip.annotations.Immutable;
import de.fhkn.in.uce.plugininterface.NATTraversalTechnique;
import de.fhkn.in.uce.plugininterface.NATTraversalTechniqueMetaData;
/**
* This comparator compares the ConnectionSetupTime in the worst case of
* {@link NATTraversalTechnique} with ascending order.
*
* <pre>
* The parameters for
* comparing the {@link NATTraversalTechnique}s is
* - direct/indirect connection: a connection without any third party instance which forwards message is preferred (direct)
* - ConnectionSetupTime: the number of messages in the worst case is used in ascending order
* </pre>
*
* Note: this comparator imposes orderings that are inconsistent with equals.
*
* @author Alexander Diener (aldiener@htwg-konstanz.de)
*
*/
@Immutable
public final class ConnectionSetupTimeComparator implements Comparator<NATTraversalTechnique>, Serializable {
private static final Comparator<NATTraversalTechnique> INSTANCE = new ConnectionSetupTimeComparator();
/**
* The version of this comparator.
*/
private static final long serialVersionUID = -1639426284815405215L;
@Override
public int compare(NATTraversalTechnique tech1, NATTraversalTechnique tech2) {
NATTraversalTechniqueMetaData o1 = tech1.getMetaData();
NATTraversalTechniqueMetaData o2 = tech2.getMetaData();
// compare direct - indirect connection
if (o1.providesDirectConnection() && !o2.providesDirectConnection()) {
return -1;
} else if (!o1.providesDirectConnection() && o2.providesDirectConnection()) {
return 1;
}
// compare maximal connection setup time
if (o1.getMaxConnectionSetupTime() < o2.getMaxConnectionSetupTime()) {
return -1;
} else if (o1.getMaxConnectionSetupTime() > o2.getMaxConnectionSetupTime()) {
return 1;
}
// compare name
return o1.getTraversalTechniqueName().compareTo(o2.getTraversalTechniqueName());
// if (o1.getMinConnectionSetupTime() < o2.getMinConnectionSetupTime())
// {
// return -1;
// } else {
// if (o1.getMinConnectionSetupTime() > o2.getMinConnectionSetupTime())
// {
// return 1;
// } else if (o1.getMaxConnectionSetupTime() <
// o2.getMaxConnectionSetupTime()) {
// return -1;
// } else if (o1.getMaxConnectionSetupTime() >
// o2.getMaxConnectionSetupTime()) {
// return 1;
// } else {
// return
// o1.getTraversalTechniqueName().compareTo(o2.getTraversalTechniqueName());
// }
// }
}
private ConnectionSetupTimeComparator() {
// private constructor
}
/**
* Returns the sole instance of {@link ConnectionSetupTimeComparator}.
*
* @return the sole instance of {@link ConnectionSetupTimeComparator}
*/
public static Comparator<NATTraversalTechnique> getInstance() {
return INSTANCE;
}
}