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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.master.handler;
20  
21  import java.io.IOException;
22  import java.util.List;
23  
24  import org.apache.hadoop.classification.InterfaceAudience;
25  import org.apache.hadoop.hbase.TableName;
26  import org.apache.hadoop.hbase.HColumnDescriptor;
27  import org.apache.hadoop.hbase.HRegionInfo;
28  import org.apache.hadoop.hbase.HTableDescriptor;
29  import org.apache.hadoop.hbase.InvalidFamilyOperationException;
30  import org.apache.hadoop.hbase.Server;
31  import org.apache.hadoop.hbase.executor.EventType;
32  import org.apache.hadoop.hbase.master.HMaster;
33  import org.apache.hadoop.hbase.master.MasterCoprocessorHost;
34  import org.apache.hadoop.hbase.master.MasterServices;
35  
36  /**
37   * Handles adding a new family to an existing table.
38   */
39  @InterfaceAudience.Private
40  public class TableAddFamilyHandler extends TableEventHandler {
41  
42    private final HColumnDescriptor familyDesc;
43  
44    public TableAddFamilyHandler(TableName tableName, HColumnDescriptor familyDesc,
45        Server server, final MasterServices masterServices) {
46      super(EventType.C_M_ADD_FAMILY, tableName, server, masterServices);
47      this.familyDesc = familyDesc;
48    }
49  
50    @Override
51    protected void prepareWithTableLock() throws IOException {
52      super.prepareWithTableLock();
53      HTableDescriptor htd = getTableDescriptor();
54      if (htd.hasFamily(familyDesc.getName())) {
55        throw new InvalidFamilyOperationException("Family '" +
56          familyDesc.getNameAsString() + "' already exists so cannot be added");
57      }
58    }
59  
60    @Override
61    protected void handleTableOperation(List<HRegionInfo> hris)
62    throws IOException {
63      MasterCoprocessorHost cpHost = ((HMaster) this.server)
64          .getMasterCoprocessorHost();
65      if(cpHost != null){
66        cpHost.preAddColumnHandler(this.tableName, this.familyDesc);
67      }
68      // Update table descriptor
69      this.masterServices.getMasterFileSystem().addColumn(tableName, familyDesc);
70      if(cpHost != null){
71        cpHost.postAddColumnHandler(this.tableName, this.familyDesc);
72      }
73    }
74  
75    @Override
76    public String toString() {
77      String name = "UnknownServerName";
78      if(server != null && server.getServerName() != null) {
79        name = server.getServerName().toString();
80      }
81      String family = "UnknownFamily";
82      if(familyDesc != null) {
83        family = familyDesc.getNameAsString();
84      }
85      return getClass().getSimpleName() + "-" + name + "-" +
86                                getSeqid() + "-" + tableName + "-" + family;
87    }
88  
89  }