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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  import java.util.ArrayList;
26  
27  /**
28   * This filter is used to filter based on the column family. It takes an
29   * operator (equal, greater, not equal, etc) and a byte [] comparator for the
30   * column family portion of a key.
31   * <p/>
32   * This filter can be wrapped with {@link org.apache.hadoop.hbase.filter.WhileMatchFilter} and {@link org.apache.hadoop.hbase.filter.SkipFilter}
33   * to add more control.
34   * <p/>
35   * Multiple filters can be combined using {@link org.apache.hadoop.hbase.filter.FilterList}.
36   * <p/>
37   * If an already known column family is looked for, use {@link org.apache.hadoop.hbase.client.Get#addFamily(byte[])}
38   * directly rather than a filter.
39   */
40  public class FamilyFilter extends CompareFilter {
41    /**
42     * Writable constructor, do not use.
43     */
44    public FamilyFilter() {
45    }
46  
47    /**
48     * Constructor.
49     *
50     * @param familyCompareOp  the compare op for column family matching
51     * @param familyComparator the comparator for column family matching
52     */
53    public FamilyFilter(final CompareOp familyCompareOp,
54                        final WritableByteArrayComparable familyComparator) {
55        super(familyCompareOp, familyComparator);
56    }
57  
58    @Override
59    public ReturnCode filterKeyValue(KeyValue v) {
60      int familyLength = v.getFamilyLength();
61      if (familyLength > 0) {
62        if (doCompare(this.compareOp, this.comparator, v.getBuffer(),
63            v.getFamilyOffset(), familyLength)) {
64          return ReturnCode.SKIP;
65        }
66      }
67      return ReturnCode.INCLUDE;
68    }
69  
70    public static Filter createFilterFromArguments(ArrayList<byte []> filterArguments) {
71      ArrayList arguments = CompareFilter.extractArguments(filterArguments);
72      CompareOp compareOp = (CompareOp)arguments.get(0);
73      WritableByteArrayComparable comparator = (WritableByteArrayComparable)arguments.get(1);
74      return new FamilyFilter(compareOp, comparator);
75  }
76  }