001/**
002 *
003 * Licensed to the Apache Software Foundation (ASF) under one
004 * or more contributor license agreements.  See the NOTICE file
005 * distributed with this work for additional information
006 * regarding copyright ownership.  The ASF licenses this file
007 * to you under the Apache License, Version 2.0 (the
008 * "License"); you may not use this file except in compliance
009 * with the License.  You may obtain a copy of the License at
010 *
011 *     http://www.apache.org/licenses/LICENSE-2.0
012 *
013 * Unless required by applicable law or agreed to in writing, software
014 * distributed under the License is distributed on an "AS IS" BASIS,
015 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
016 * See the License for the specific language governing permissions and
017 * limitations under the License.
018 */
019package org.apache.hadoop.hbase.wal;
020
021import org.apache.hadoop.conf.Configuration;
022import org.apache.hadoop.hbase.NamespaceDescriptor;
023import org.apache.yetus.audience.InterfaceAudience;
024import org.apache.hadoop.hbase.util.Bytes;
025import org.apache.hadoop.hbase.wal.RegionGroupingProvider.RegionGroupingStrategy;
026
027/**
028 * A WAL grouping strategy based on namespace.
029 * Notice: the wal-group mapping might change if we support dynamic namespace updating later,
030 * and special attention needed if we support feature like group-based replication.
031 */
032@InterfaceAudience.Private
033public class NamespaceGroupingStrategy implements RegionGroupingStrategy {
034  String providerId;
035
036  @Override
037  public String group(byte[] identifier, byte[] namespace) {
038    String namespaceString;
039    if (namespace == null || namespace.length == 0) {
040      namespaceString = NamespaceDescriptor.DEFAULT_NAMESPACE_NAME_STR;
041    } else {
042      namespaceString = Bytes.toString(namespace);
043    }
044    return providerId + GROUP_NAME_DELIMITER + namespaceString;
045  }
046
047  @Override
048  public void init(Configuration config, String providerId) {
049    this.providerId = providerId;
050  }
051
052}