001 /* 002 * JBoss, Home of Professional Open Source. 003 * Copyright 2008, Red Hat Middleware LLC, and individual contributors 004 * as indicated by the @author tags. See the copyright.txt file in the 005 * distribution for a full listing of individual contributors. 006 * 007 * This is free software; you can redistribute it and/or modify it 008 * under the terms of the GNU Lesser General Public License as 009 * published by the Free Software Foundation; either version 2.1 of 010 * the License, or (at your option) any later version. 011 * 012 * This software is distributed in the hope that it will be useful, 013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 015 * Lesser General Public License for more details. 016 * 017 * You should have received a copy of the GNU Lesser General Public 018 * License along with this software; if not, write to the Free 019 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 020 * 02110-1301 USA, or see the FSF site: http://www.fsf.org. 021 */ 022 package org.jboss.dna.graph.cache; 023 024 import java.util.concurrent.TimeUnit; 025 import org.jboss.dna.common.util.CheckArg; 026 027 /** 028 * @author Randall Hauch 029 */ 030 public class BasicCachePolicy implements CachePolicy { 031 032 private static final long serialVersionUID = 1L; 033 private long timeToLiveInMillis = 0L; 034 035 public BasicCachePolicy() { 036 } 037 038 public BasicCachePolicy( long timeToCache, 039 TimeUnit unit ) { 040 CheckArg.isNotNull(unit, "unit"); 041 this.timeToLiveInMillis = TimeUnit.MILLISECONDS.convert(timeToCache, unit); 042 } 043 044 /** 045 * {@inheritDoc} 046 * 047 * @see org.jboss.dna.graph.cache.CachePolicy#getTimeToLive() 048 */ 049 public long getTimeToLive() { 050 return this.timeToLiveInMillis; 051 } 052 053 /** 054 * Set the time for values and information to live in the cache. 055 * 056 * @param timeToLive Sets timeToLive to the specified value. 057 * @param unit the unit in which the time to live value is defined 058 */ 059 public void setTimeToLive( long timeToLive, 060 TimeUnit unit ) { 061 this.timeToLiveInMillis = TimeUnit.NANOSECONDS.convert(timeToLive, unit); 062 } 063 064 public boolean isEmpty() { 065 return this.timeToLiveInMillis == 0; 066 } 067 068 public CachePolicy getUnmodifiable() { 069 return new ImmutableCachePolicy(this.getTimeToLive()); 070 } 071 072 /** 073 * {@inheritDoc} 074 * 075 * @see java.lang.Object#equals(java.lang.Object) 076 */ 077 @Override 078 public boolean equals( Object obj ) { 079 if (obj == this) return true; 080 if (obj instanceof CachePolicy) { 081 CachePolicy that = (CachePolicy)obj; 082 if (this.getTimeToLive() != that.getTimeToLive()) return false; 083 if (obj instanceof BasicCachePolicy) return true; 084 } 085 return false; 086 } 087 088 /** 089 * {@inheritDoc} 090 * 091 * @see java.lang.Object#toString() 092 */ 093 @Override 094 public String toString() { 095 return "{ TTL=" + this.timeToLiveInMillis + " ms }"; 096 } 097 098 }