001    /**
002     * Copyright (c) 2000-2012 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.dao.shard;
016    
017    import com.liferay.portal.kernel.dao.shard.ShardUtil;
018    import com.liferay.portal.util.PortalInstances;
019    
020    import java.util.Map;
021    
022    /**
023     * @author Alexander Chow
024     */
025    public class RoundRobinShardSelector implements ShardSelector {
026    
027            public String getShardName(
028                    String scope, String shardName, Map<String, String> params) {
029    
030                    if (scope.equals(ShardSelector.COMPANY_SCOPE)) {
031                            String[] availableShardNames = ShardUtil.getAvailableShardNames();
032    
033                            int instances = PortalInstances.getCompanyIds().length;
034                            int shards = availableShardNames.length;
035    
036                            return availableShardNames[instances % shards];
037                    }
038                    else {
039                            return ShardUtil.getDefaultShardName();
040                    }
041            }
042    
043    }