hbase-server/src/main/java/org/apache/hadoop/hbase/wal/NamespaceGroupingStrategy.java

   1 /**
   2  *
   3  * Licensed to the Apache Software Foundation (ASF) under one
   4  * or more contributor license agreements.  See the NOTICE file
   5  * distributed with this work for additional information
   6  * regarding copyright ownership.  The ASF licenses this file
   7  * to you under the Apache License, Version 2.0 (the
   8  * "License"); you may not use this file except in compliance
   9  * with the License.  You may obtain a copy of the License at
  10  *
  11  *     http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  */
  19 package org.apache.hadoop.hbase.wal;
  20
  21 import org.apache.hadoop.conf.Configuration;
  22 import org.apache.hadoop.hbase.NamespaceDescriptor;
  23 import org.apache.yetus.audience.InterfaceAudience;
  24 import org.apache.hadoop.hbase.util.Bytes;
  25 import org.apache.hadoop.hbase.wal.RegionGroupingProvider.RegionGroupingStrategy;
  26
  27 /**
  28  * A WAL grouping strategy based on namespace.
  29  * Notice: the wal-group mapping might change if we support dynamic namespace updating later,
  30  * and special attention needed if we support feature like group-based replication.
  31  */
  32 @InterfaceAudience.Private
  33 public class NamespaceGroupingStrategy implements RegionGroupingStrategy {
  34   String providerId;
  35
  36   @Override
  37   public String group(byte[] identifier, byte[] namespace) {
  38     String namespaceString;
  39     if (namespace == null || namespace.length == 0) {
  40       namespaceString = NamespaceDescriptor.DEFAULT_NAMESPACE_NAME_STR;
  41     } else {
  42       namespaceString = Bytes.toString(namespace);
  43     }
  44     return providerId + GROUP_NAME_DELIMITER + namespaceString;
  45   }
  46
  47   @Override
  48   public void init(Configuration config, String providerId) {
  49     this.providerId = providerId;
  50   }
  51
  52 }