001/**
002 *
003 * Copyright (c) 2014, the Railo Company Ltd. All rights reserved.
004 *
005 * This library is free software; you can redistribute it and/or
006 * modify it under the terms of the GNU Lesser General Public
007 * License as published by the Free Software Foundation; either 
008 * version 2.1 of the License, or (at your option) any later version.
009 * 
010 * This library is distributed in the hope that it will be useful,
011 * but WITHOUT ANY WARRANTY; without even the implied warranty of
012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013 * Lesser General Public License for more details.
014 * 
015 * You should have received a copy of the GNU Lesser General Public 
016 * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
017 * 
018 **/
019package lucee.commons.collection.concurrent;
020
021import java.util.Random;
022
023import lucee.commons.collection.concurrent.ConcurrentLinkedHashMapPro.Entry;
024
025public class RandomPolicy implements EvictionPolicy {
026
027        Random random = new Random();
028        
029        @Override
030        public boolean accessOrder() {
031                return false;
032        }
033        
034        @Override
035        public boolean insertionOrder() {
036                return false;
037        }
038        
039        @Override
040        public Entry<?, ?> evictElement(Entry<?, ?> head) {
041                int hops = random.nextInt();
042                Entry<?,?> entryToEvict = head.getAfter();
043                for(int i = 0; i < hops; i++)
044                        entryToEvict = entryToEvict.getAfter();
045                return entryToEvict;
046        }
047
048        @Override
049        public Entry<?, ?> recordInsertion(Entry<?, ?> head, Entry<?, ?> insertedEntry) {
050                return null;
051        }
052
053        @Override
054        public Entry<?, ?> recordAccess(Entry<?, ?> head, Entry<?, ?> accessedEntry) {
055                return null;
056        }
057
058}