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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.HRegionInfo;
26  import org.apache.hadoop.hbase.HTableDescriptor;
27  import org.apache.hadoop.hbase.Server;
28  import org.apache.hadoop.hbase.executor.EventType;
29  import org.apache.hadoop.hbase.master.HMaster;
30  import org.apache.hadoop.hbase.master.MasterCoprocessorHost;
31  import org.apache.hadoop.hbase.master.MasterFileSystem;
32  import org.apache.hadoop.hbase.master.MasterServices;
33  import org.apache.hadoop.hbase.util.Bytes;
34  
35  /**
36   * Handles adding a new family to an existing table.
37   */
38  @InterfaceAudience.Private
39  public class TableDeleteFamilyHandler extends TableEventHandler {
40  
41    private byte [] familyName;
42  
43    public TableDeleteFamilyHandler(byte[] tableName, byte [] familyName,
44        Server server, final MasterServices masterServices) throws IOException {
45      super(EventType.C_M_DELETE_FAMILY, tableName, server, masterServices);
46      this.familyName = familyName;
47    }
48  
49    @Override
50    protected void prepareWithTableLock() throws IOException {
51      super.prepareWithTableLock();
52      HTableDescriptor htd = getTableDescriptor();
53      this.familyName = hasColumnFamily(htd, familyName);
54    }
55  
56    @Override
57    protected void handleTableOperation(List<HRegionInfo> hris) throws IOException {
58      MasterCoprocessorHost cpHost = ((HMaster) this.server)
59          .getCoprocessorHost();
60      if (cpHost != null) {
61        cpHost.preDeleteColumnHandler(this.tableName, this.familyName);
62      }
63      // Update table descriptor
64      this.masterServices.getMasterFileSystem().deleteColumn(tableName, familyName);
65      // Remove the column family from the file system
66      MasterFileSystem mfs = this.masterServices.getMasterFileSystem();
67      for (HRegionInfo hri : hris) {
68        // Delete the family directory in FS for all the regions one by one
69        mfs.deleteFamilyFromFS(hri, familyName);
70      }
71      if (cpHost != null) {
72        cpHost.postDeleteColumnHandler(this.tableName, this.familyName);
73      }
74    }
75  
76    @Override
77    public String toString() {
78      String name = "UnknownServerName";
79      if(server != null && server.getServerName() != null) {
80        name = server.getServerName().toString();
81      }
82      String family = "UnknownFamily";
83      if(familyName != null) {
84        family = Bytes.toString(familyName);
85      }
86      return getClass().getSimpleName() + "-" + name + "-" + getSeqid() + "-" + tableNameStr + "-" + family;
87    }
88  }