com.mchange.v1.util.NumberedObjectCache Maven / Gradle / Ivy
/*
* Distributed as part of mchange-commons-java v.0.2.3
*
* Copyright (C) 2012 Machinery For Change, Inc.
*
* Author: Steve Waldman
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License version 2.1, as
* published by the Free Software Foundation.
*
* 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; see the file LICENSE. If not, write to the
* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA.
*/
package com.mchange.v1.util;
import java.util.*;
public abstract class NumberedObjectCache
{
ArrayList al = new ArrayList();
public Object getObject(int num) throws Exception
{
Object out = null;
int req_cap = num + 1;
if (req_cap > al.size())
{
al.ensureCapacity(req_cap * 2);
for (int i = al.size(), end = req_cap * 2; i < end; ++i)
al.add(null);
out = addToCache(num);
}
else
{
out = al.get(num);
if (out == null)
out = addToCache(num);
}
return out;
}
private Object addToCache(int num) throws Exception
{
Object out = findObject(num);
al.set(num, out);
return out;
}
protected abstract Object findObject(int num) throws Exception;
}