001    /**
002     * Copyright (c) 2000-2010 Liferay, Inc. All rights reserved.
003     *
004     * This library is free software; you can redistribute it and/or modify it under
005     * the terms of the GNU Lesser General Public License as published by the Free
006     * Software Foundation; either version 2.1 of the License, or (at your option)
007     * any later version.
008     *
009     * This library is distributed in the hope that it will be useful, but WITHOUT
010     * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
011     * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
012     * details.
013     */
014    
015    package com.liferay.portal.kernel.cache.cluster;
016    
017    import java.util.List;
018    import java.util.concurrent.atomic.AtomicLong;
019    
020    /**
021     * @author Shuyang Zhou
022     */
023    public class UniformPortalCacheClusterChannelSelector
024            implements PortalCacheClusterChannelSelector {
025    
026            public long getSelectedNumber() {
027                    return _eventCounter.get();
028            }
029    
030            public PortalCacheClusterChannel select(
031                    List<PortalCacheClusterChannel> portalCacheClusterChannels,
032                    PortalCacheClusterEvent portalCacheClusterEvent) {
033    
034                    long count = _eventCounter.getAndIncrement();
035                    int size = portalCacheClusterChannels.size();
036    
037                    return portalCacheClusterChannels.get((int)(count % size));
038            }
039    
040            private AtomicLong _eventCounter = new AtomicLong(0);
041    
042    }