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.io.Serializable;
027    import net.jcip.annotations.Immutable;
028    
029    /**
030     * The specification of how node data is to be cached. The time values provided are relative, allowing the same cache policy
031     * instance to be shared among multiple {@link Cacheable} objects.
032     * 
033     * @author Randall Hauch
034     */
035    @Immutable
036    public interface CachePolicy extends Serializable {
037    
038        /**
039         * Get the system time in milliseconds before which the node data remains valid.
040         * 
041         * @return the number of milliseconds that the cached data should be used before consulting the original source.
042         */
043        public long getTimeToLive();
044    
045    }