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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  
21  package org.apache.hadoop.hbase.filter;
22  
23  import org.apache.hadoop.hbase.KeyValue;
24  
25  /**
26   * This filter is used to filter based on the column family. It takes an
27   * operator (equal, greater, not equal, etc) and a byte [] comparator for the
28   * column family portion of a key.
29   * <p/>
30   * This filter can be wrapped with {@link org.apache.hadoop.hbase.filter.WhileMatchFilter} and {@link org.apache.hadoop.hbase.filter.SkipFilter}
31   * to add more control.
32   * <p/>
33   * Multiple filters can be combined using {@link org.apache.hadoop.hbase.filter.FilterList}.
34   * <p/>
35   * If an already known column family is looked for, use {@link org.apache.hadoop.hbase.client.Get#addFamily(byte[])}
36   * directly rather than a filter.
37   */
38  public class FamilyFilter extends CompareFilter {
39    /**
40     * Writable constructor, do not use.
41     */
42    public FamilyFilter() {
43    }
44  
45    /**
46     * Constructor.
47     *
48     * @param familyCompareOp  the compare op for column family matching
49     * @param familyComparator the comparator for column family matching
50     */
51    public FamilyFilter(final CompareOp familyCompareOp,
52                        final WritableByteArrayComparable familyComparator) {
53        super(familyCompareOp, familyComparator);
54    }
55  
56    @Override
57    public ReturnCode filterKeyValue(KeyValue v) {
58      int familyLength = v.getFamilyLength();
59      if (familyLength > 0) {
60        if (doCompare(this.compareOp, this.comparator, v.getBuffer(),
61            v.getFamilyOffset(), familyLength)) {
62          return ReturnCode.SKIP;
63        }
64      }
65      return ReturnCode.INCLUDE;
66    }
67  }