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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  
20  package org.apache.hadoop.hbase.filter;
21  
22  import com.google.protobuf.InvalidProtocolBufferException;
23  import org.apache.hadoop.classification.InterfaceAudience;
24  import org.apache.hadoop.classification.InterfaceStability;
25  import org.apache.hadoop.hbase.KeyValue;
26  import org.apache.hadoop.hbase.exceptions.DeserializationException;
27  import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
28  import org.apache.hadoop.hbase.protobuf.generated.FilterProtos;
29  
30  import java.io.IOException;
31  import java.util.ArrayList;
32  
33  /**
34   * This filter is used to filter based on column value. It takes an
35   * operator (equal, greater, not equal, etc) and a byte [] comparator for the
36   * cell value.
37   * <p>
38   * This filter can be wrapped with {@link WhileMatchFilter} and {@link SkipFilter}
39   * to add more control.
40   * <p>
41   * Multiple filters can be combined using {@link FilterList}.
42   * <p>
43   * To test the value of a single qualifier when scanning multiple qualifiers,
44   * use {@link SingleColumnValueFilter}.
45   */
46  @InterfaceAudience.Public
47  @InterfaceStability.Stable
48  public class ValueFilter extends CompareFilter {
49  
50    /**
51     * Constructor.
52     * @param valueCompareOp the compare op for value matching
53     * @param valueComparator the comparator for value matching
54     */
55    public ValueFilter(final CompareOp valueCompareOp,
56        final ByteArrayComparable valueComparator) {
57      super(valueCompareOp, valueComparator);
58    }
59  
60    @Override
61    public ReturnCode filterKeyValue(KeyValue v) {
62      if (doCompare(this.compareOp, this.comparator, v.getBuffer(),
63          v.getValueOffset(), v.getValueLength())) {
64        return ReturnCode.SKIP;
65      }
66      return ReturnCode.INCLUDE;
67    }
68  
69    public static Filter createFilterFromArguments(ArrayList<byte []> filterArguments) {
70      ArrayList arguments = CompareFilter.extractArguments(filterArguments);
71      CompareOp compareOp = (CompareOp)arguments.get(0);
72      ByteArrayComparable comparator = (ByteArrayComparable)arguments.get(1);
73      return new ValueFilter(compareOp, comparator);
74    }
75  
76    /**
77     * @return The filter serialized using pb
78     */
79    public byte [] toByteArray() {
80      FilterProtos.ValueFilter.Builder builder =
81        FilterProtos.ValueFilter.newBuilder();
82      builder.setCompareFilter(super.convert());
83      return builder.build().toByteArray();
84    }
85  
86    /**
87     * @param pbBytes A pb serialized {@link ValueFilter} instance
88     * @return An instance of {@link ValueFilter} made from <code>bytes</code>
89     * @throws DeserializationException
90     * @see #toByteArray
91     */
92    public static ValueFilter parseFrom(final byte [] pbBytes)
93    throws DeserializationException {
94      FilterProtos.ValueFilter proto;
95      try {
96        proto = FilterProtos.ValueFilter.parseFrom(pbBytes);
97      } catch (InvalidProtocolBufferException e) {
98        throw new DeserializationException(e);
99      }
100     final CompareOp valueCompareOp =
101       CompareOp.valueOf(proto.getCompareFilter().getCompareOp().name());
102     ByteArrayComparable valueComparator = null;
103     try {
104       if (proto.getCompareFilter().hasComparator()) {
105         valueComparator = ProtobufUtil.toComparator(proto.getCompareFilter().getComparator());
106       }
107     } catch (IOException ioe) {
108       throw new DeserializationException(ioe);
109     }
110     return new ValueFilter(valueCompareOp,valueComparator);
111   }
112 
113   /**
114    * @param other
115    * @return true if and only if the fields of the filter that are serialized
116    * are equal to the corresponding fields in other.  Used for testing.
117    */
118   boolean areSerializedFieldsEqual(Filter o) {
119     if (o == this) return true;
120     if (!(o instanceof ValueFilter)) return false;
121 
122     return super.areSerializedFieldsEqual(o);
123   }
124 }