001 /* 002 * JBoss DNA (http://www.jboss.org/dna) 003 * See the COPYRIGHT.txt file distributed with this work for information 004 * regarding copyright ownership. Some portions may be licensed 005 * to Red Hat, Inc. under one or more contributor license agreements. 006 * See the AUTHORS.txt file in the distribution for a full listing of 007 * individual contributors. 008 * 009 * JBoss DNA is free software. Unless otherwise indicated, all code in JBoss DNA 010 * is licensed to you under the terms of the GNU Lesser General Public License as 011 * published by the Free Software Foundation; either version 2.1 of 012 * the License, or (at your option) any later version. 013 * 014 * JBoss DNA is distributed in the hope that it will be useful, 015 * but WITHOUT ANY WARRANTY; without even the implied warranty of 016 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 017 * Lesser General Public License for more details. 018 * 019 * You should have received a copy of the GNU Lesser General Public 020 * License along with this software; if not, write to the Free 021 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 022 * 02110-1301 USA, or see the FSF site: http://www.fsf.org. 023 */ 024 package org.jboss.dna.graph.cache; 025 026 import java.util.concurrent.TimeUnit; 027 import org.jboss.dna.common.util.CheckArg; 028 029 /** 030 * @author Randall Hauch 031 */ 032 public class BasicCachePolicy implements CachePolicy { 033 034 private static final long serialVersionUID = 1L; 035 private long timeToLiveInMillis = 0L; 036 037 public BasicCachePolicy() { 038 } 039 040 public BasicCachePolicy( long timeToCache, 041 TimeUnit unit ) { 042 CheckArg.isNotNull(unit, "unit"); 043 this.timeToLiveInMillis = TimeUnit.MILLISECONDS.convert(timeToCache, unit); 044 } 045 046 /** 047 * {@inheritDoc} 048 * 049 * @see org.jboss.dna.graph.cache.CachePolicy#getTimeToLive() 050 */ 051 public long getTimeToLive() { 052 return this.timeToLiveInMillis; 053 } 054 055 /** 056 * Set the time for values and information to live in the cache. 057 * 058 * @param timeToLive Sets timeToLive to the specified value. 059 * @param unit the unit in which the time to live value is defined 060 */ 061 public void setTimeToLive( long timeToLive, 062 TimeUnit unit ) { 063 this.timeToLiveInMillis = TimeUnit.NANOSECONDS.convert(timeToLive, unit); 064 } 065 066 public boolean isEmpty() { 067 return this.timeToLiveInMillis == 0; 068 } 069 070 public CachePolicy getUnmodifiable() { 071 return new ImmutableCachePolicy(this.getTimeToLive()); 072 } 073 074 /** 075 * {@inheritDoc} 076 * 077 * @see java.lang.Object#equals(java.lang.Object) 078 */ 079 @Override 080 public boolean equals( Object obj ) { 081 if (obj == this) return true; 082 if (obj instanceof CachePolicy) { 083 CachePolicy that = (CachePolicy)obj; 084 if (this.getTimeToLive() != that.getTimeToLive()) return false; 085 if (obj instanceof BasicCachePolicy) return true; 086 } 087 return false; 088 } 089 090 /** 091 * {@inheritDoc} 092 * 093 * @see java.lang.Object#toString() 094 */ 095 @Override 096 public String toString() { 097 return "{ TTL=" + this.timeToLiveInMillis + " ms }"; 098 } 099 100 }