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* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
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package org.wildfly.clustering.singleton.election;
import java.util.Arrays;
import java.util.List;
import org.wildfly.clustering.group.Node;
import org.wildfly.clustering.singleton.SingletonElectionPolicy;
/**
* An election policy that always elects a preferred node, and defers to a default policy
* if the preferred node is not a candidate. The means of specifying the preferred node is
* the responsibility of the extending class.
* @author Paul Ferraro
*/
public class PreferredSingletonElectionPolicy implements SingletonElectionPolicy {
private final List<Preference> preferences;
private final SingletonElectionPolicy policy;
public PreferredSingletonElectionPolicy(SingletonElectionPolicy policy, Preference... preferences) {
this(policy, Arrays.asList(preferences));
}
public PreferredSingletonElectionPolicy(SingletonElectionPolicy policy, List<Preference> preferences) {
this.policy = policy;
this.preferences = preferences;
}
@Override
public Node elect(List<Node> candidates) {
for (Preference preference: this.preferences) {
for (Node candidate: candidates) {
if (preference.preferred(candidate)) {
return candidate;
}
}
}
return this.policy.elect(candidates);
}
}