/*
* JBoss, Home of Professional Open Source
* Copyright 2010 Red Hat Inc. and/or its affiliates and other
* contributors as indicated by the @author tags. All rights reserved.
* See the copyright.txt 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
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.infinispan.distribution;
import org.infinispan.Cache;
import java.io.Serializable;
import java.util.Random;
import static org.infinispan.distribution.DistributionTestHelper.addressOf;
import static org.infinispan.distribution.DistributionTestHelper.isFirstOwner;
/**
* A special type of key that if passed a cache in its constructor, will ensure it will always be assigned to that cache
* (plus however many additional caches in the hash space).
*
* Note that this only works if all the caches have joined a single cluster before creating the key.
* If the cluster membership changes then the keys may move to other servers.
*/
public class MagicKey implements Serializable {
/**
* The serialVersionUID
*/
private static final long serialVersionUID = -835275755945753954L;
String name = null;
int hashcode;
String address;
public MagicKey(Cache<?, ?> toMapTo) {
address = addressOf(toMapTo).toString();
Random r = new Random();
Object dummy;
do {
// create a dummy object with this hashcode
final int hc = r.nextInt();
dummy = new Object() {
@Override
public int hashCode() {
return hc;
}
};
} while (!isFirstOwner(toMapTo, dummy));
// we have found a hashcode that works!
hashcode = dummy.hashCode();
}
public MagicKey(Cache<?, ?> toMapTo, String name) {
this(toMapTo);
this.name = name;
}
@Override
public int hashCode () {
return hashcode;
}
@Override
public boolean equals (Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
MagicKey magicKey = (MagicKey) o;
if (hashcode != magicKey.hashcode) return false;
if (address != null ? !address.equals(magicKey.address) : magicKey.address != null) return false;
return true;
}
@Override
public String toString() {
return "MagicKey{" +
(name == null ? "" : "name=" + name + ", ") +
"hashcode=" + hashcode +
", address='" + address + '\'' +
'}';
}
}