/*
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Feb 9, 2009
*/
package com.bigdata.cache;
import java.util.concurrent.ConcurrentHashMap;
/**
* Extends the basic behavior to clear stale references from a backing hard
* reference queue. The weak reference values for entries whose hard reference
* is cleared from the backing hard reference queue WILL NOT be cleared from
* this map as long as those references remain strongly reachable.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*
* @see SynchronizedHardReferenceQueueWithTimeout
*/
public class ConcurrentWeakValueCacheWithTimeout<K, V> extends
ConcurrentWeakValueCache<K, V> {
/**
* Ctor variant using a {@link SynchronizedHardReferenceQueueWithTimeout}
* with the specified capacity and timeout for stale references.
*
* @param timeout The timeout in nanoseconds.
*/
public ConcurrentWeakValueCacheWithTimeout(final int queueCapacity,
final long timeout) {
this(queueCapacity, 0.75f/* loadFactor */, 16/* concurrencyLevel */,
timeout);
}
/**
* Ctor variant using a {@link SynchronizedHardReferenceQueueWithTimeout}
* with the specified capacity, timeout for stale references, and the
* specified concurrency level for the inner {@link ConcurrentHashMap} used
* by this class.
*
* @param timeout The timeout in nanoseconds.
*/
public ConcurrentWeakValueCacheWithTimeout(final int queueCapacity,
final float loadFactor, final int concurrencyLevel,
final long timeout) {
super(new SynchronizedHardReferenceQueueWithTimeout<V>(queueCapacity,
timeout), loadFactor, concurrencyLevel, true/* removeClearedReferences */
);
}
}