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1   /**
2    * Copyright 2010 The Apache Software Foundation
3    *
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *     http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing, software
15   * distributed under the License is distributed on an "AS IS" BASIS,
16   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17   * See the License for the specific language governing permissions and
18   * limitations under the License.
19   */
20  package org.apache.hadoop.hbase.master;
21  
22  import org.apache.hadoop.hbase.HColumnDescriptor;
23  import org.apache.hadoop.hbase.HRegionInfo;
24  import org.apache.hadoop.hbase.ipc.HRegionInterface;
25  
26  import java.io.IOException;
27  
28  /** Instantiated to add a column family to a table */
29  class AddColumn extends ColumnOperation {
30    private final HColumnDescriptor newColumn;
31  
32    AddColumn(final HMaster master, final byte [] tableName,
33      final HColumnDescriptor newColumn)
34    throws IOException {
35      super(master, tableName);
36      this.newColumn = newColumn;
37    }
38  
39    @Override
40    protected void postProcessMeta(MetaRegion m, HRegionInterface server)
41    throws IOException {
42      for (HRegionInfo i: unservedRegions) {
43        // All we need to do to add a column is add it to the table descriptor.
44        // When the region is brought on-line, it will find the column missing
45        // and create it.
46        i.getTableDesc().addFamily(newColumn);
47        updateRegionInfo(server, m.getRegionName(), i);
48      }
49    }
50  }