AbstractEncounterCounter.java

/*
 * Distributed as part of mchange-commons-java 0.2.11
 *
 * Copyright (C) 2015 Machinery For Change, Inc.
 *
 * Author: Steve Waldman <swaldman@mchange.com>
 *
 * This library is free software; you can redistribute it and/or modify
 * it under the terms of EITHER:
 *
 *     1) The GNU Lesser General Public License (LGPL), version 2.1, as 
 *        published by the Free Software Foundation
 *
 * OR
 *
 *     2) The Eclipse Public License (EPL), version 1.0
 *
 * You may choose which license to accept if you wish to redistribute
 * or modify this work. You may offer derivatives of this work
 * under the license you have chosen, or you may provide the same
 * choice of license which you have been offered here.
 *
 * 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.
 *
 * You should have received copies of both LGPL v2.1 and EPL v1.0
 * along with this software; see the files LICENSE-EPL and LICENSE-LGPL.
 * If not, the text of these licenses are currently available at
 *
 * LGPL v2.1: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
 *  EPL v1.0: http://www.eclipse.org/org/documents/epl-v10.php 
 * 
 */

package com.mchange.v2.encounter;

import java.util.Map;

class AbstractEncounterCounter implements EncounterCounter
{
    final static Long ONE = new Long(1);
    Map m;

    AbstractEncounterCounter(Map m)
    { this.m = m; }

    /**
     *  @return how many times have I seen this object before?
     */
    public long encounter(Object o)
    {
	Long oldLong = (Long) m.get(o);
	Long newLong;
	long out;
	if (oldLong == null)
	    {
		out = 0;
		newLong = ONE;
	    }
	else
	    {
		out = oldLong.longValue(); 
		newLong = new Long(out + 1);
	    }
	m.put( o, newLong );
	return out;
    }

    public long reset(Object o)
    {
	long out = encounter(o);
	m.remove( o );
	return out;
    }

    public void resetAll()
    { m.clear(); }
}