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; 019 020import java.io.IOException; 021import java.util.ArrayList; 022import java.util.List; 023import org.apache.hadoop.hbase.client.Connection; 024import org.apache.hadoop.hbase.client.Get; 025import org.apache.hadoop.hbase.client.Result; 026import org.apache.hadoop.hbase.client.Scan; 027import org.apache.hadoop.hbase.client.Table; 028import org.apache.hadoop.hbase.protobuf.ProtobufUtil; 029import org.apache.hadoop.hbase.protobuf.generated.RSGroupProtos; 030import org.apache.hadoop.hbase.rsgroup.RSGroupInfo; 031import org.apache.hadoop.hbase.util.Bytes; 032import org.apache.yetus.audience.InterfaceAudience; 033 034/** 035 * Read rs group information from <code>hbase:rsgroup</code>. 036 */ 037@InterfaceAudience.Private 038public final class RSGroupTableAccessor { 039 040 // Assigned before user tables 041 private static final TableName RSGROUP_TABLE_NAME = 042 TableName.valueOf(NamespaceDescriptor.SYSTEM_NAMESPACE_NAME_STR, "rsgroup"); 043 private static final byte[] META_FAMILY_BYTES = Bytes.toBytes("m"); 044 private static final byte[] META_QUALIFIER_BYTES = Bytes.toBytes("i"); 045 046 private RSGroupTableAccessor() { 047 } 048 049 public static boolean isRSGroupsEnabled(Connection connection) throws IOException { 050 return connection.getAdmin().tableExists(RSGROUP_TABLE_NAME); 051 } 052 053 public static List<RSGroupInfo> getAllRSGroupInfo(Connection connection) throws IOException { 054 try (Table rsGroupTable = connection.getTable(RSGROUP_TABLE_NAME)) { 055 List<RSGroupInfo> rsGroupInfos = new ArrayList<>(); 056 for (Result result : rsGroupTable.getScanner(new Scan())) { 057 RSGroupInfo rsGroupInfo = getRSGroupInfo(result); 058 if (rsGroupInfo != null) { 059 rsGroupInfos.add(rsGroupInfo); 060 } 061 } 062 return rsGroupInfos; 063 } 064 } 065 066 private static RSGroupInfo getRSGroupInfo(Result result) throws IOException { 067 byte[] rsGroupInfo = result.getValue(META_FAMILY_BYTES, META_QUALIFIER_BYTES); 068 if (rsGroupInfo == null) { 069 return null; 070 } 071 RSGroupProtos.RSGroupInfo proto = RSGroupProtos.RSGroupInfo.parseFrom(rsGroupInfo); 072 return ProtobufUtil.toGroupInfo(proto); 073 } 074 075 public static RSGroupInfo getRSGroupInfo(Connection connection, byte[] rsGroupName) 076 throws IOException { 077 try (Table rsGroupTable = connection.getTable(RSGROUP_TABLE_NAME)) { 078 Result result = rsGroupTable.get(new Get(rsGroupName)); 079 return getRSGroupInfo(result); 080 } 081 } 082}