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