io.logspace.agent.shaded.mchange.v2.coalesce.AbstractWeakCoalescer Maven / Gradle / Ivy
/*
* Distributed as part of c3p0 v.0.9.1.1
*
* Copyright (C) 2005 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 io.logspace.agent.shaded.mchange.v2.coalesce;
import java.util.*;
import java.lang.ref.WeakReference;
class AbstractWeakCoalescer implements Coalescer
{
Map wcoalesced;
AbstractWeakCoalescer( Map wcoalesced )
{ this.wcoalesced = wcoalesced; }
public Object coalesce( Object o )
{
//System.err.println("AbstractWeakCoalescer.coalesce( " + o + " )");
Object out = null;
WeakReference wr = (WeakReference) wcoalesced.get( o );
if ( wr != null )
out = wr.get(); //there is a conceivable race that would
//permit wr be cleared
if ( out == null )
{
wcoalesced.put( o , new WeakReference(o) );
out = o;
}
return out;
}
public int countCoalesced()
{ return wcoalesced.size(); }
public Iterator iterator()
{ return new CoalescerIterator( wcoalesced.keySet().iterator() ); }
}