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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 column value. It takes an
29   * operator (equal, greater, not equal, etc) and a byte [] comparator for the
30   * cell value.
31   * <p>
32   * This filter can be wrapped with {@link WhileMatchFilter} and {@link SkipFilter}
33   * to add more control.
34   * <p>
35   * Multiple filters can be combined using {@link FilterList}.
36   * <p>
37   * To test the value of a single qualifier when scanning multiple qualifiers,
38   * use {@link SingleColumnValueFilter}.
39   */
40  public class ValueFilter extends CompareFilter {
41  
42    /**
43     * Writable constructor, do not use.
44     */
45    public ValueFilter() {
46    }
47  
48    /**
49     * Constructor.
50     * @param valueCompareOp the compare op for value matching
51     * @param valueComparator the comparator for value matching
52     */
53    public ValueFilter(final CompareOp valueCompareOp,
54        final WritableByteArrayComparable valueComparator) {
55      super(valueCompareOp, valueComparator);
56    }
57  
58    @Override
59    public ReturnCode filterKeyValue(KeyValue v) {
60      if (doCompare(this.compareOp, this.comparator, v.getBuffer(),
61          v.getValueOffset(), v.getValueLength())) {
62        return ReturnCode.SKIP;
63      }
64      return ReturnCode.INCLUDE;
65    }
66  
67    public static Filter createFilterFromArguments(ArrayList<byte []> filterArguments) {
68      ArrayList arguments = CompareFilter.extractArguments(filterArguments);
69      CompareOp compareOp = (CompareOp)arguments.get(0);
70      WritableByteArrayComparable comparator = (WritableByteArrayComparable)arguments.get(1);
71      return new ValueFilter(compareOp, comparator);
72  }
73  }