001    /**
002     * Copyright (c) 2000-2011 Liferay, Inc. All rights reserved.
003     *
004     * The contents of this file are subject to the terms of the Liferay Enterprise
005     * Subscription License ("License"). You may not use this file except in
006     * compliance with the License. You can obtain a copy of the License by
007     * contacting Liferay, Inc. See the License for the specific language governing
008     * permissions and limitations under the License, including but not limited to
009     * distribution rights of the Software.
010     *
011     *
012     *
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    }