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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  
19  package org.apache.hadoop.hbase.filter;
20  
21  import java.util.Set;
22  import java.util.TreeSet;
23  
24  import org.apache.hadoop.hbase.Cell;
25  import org.apache.hadoop.hbase.CellUtil;
26  import org.apache.hadoop.hbase.classification.InterfaceAudience;
27  import org.apache.hadoop.hbase.classification.InterfaceStability;
28  import org.apache.hadoop.hbase.exceptions.DeserializationException;
29  import org.apache.hadoop.hbase.protobuf.generated.FilterProtos;
30  import org.apache.hadoop.hbase.util.ByteStringer;
31  import org.apache.hadoop.hbase.util.Bytes;
32  
33  import com.google.protobuf.ByteString;
34  import com.google.protobuf.InvalidProtocolBufferException;
35  
36  /**
37   * The filter looks for the given columns in KeyValue. Once there is a match for
38   * any one of the columns, it returns ReturnCode.NEXT_ROW for remaining
39   * KeyValues in the row.
40   * <p>
41   * Note : It may emit KVs which do not have the given columns in them, if
42   * these KVs happen to occur before a KV which does have a match. Given this
43   * caveat, this filter is only useful for special cases
44   * like {@link org.apache.hadoop.hbase.mapreduce.RowCounter}.
45   * <p>
46   * @deprecated Deprecated in 2.0. See HBASE-13347
47   */
48  @InterfaceAudience.Public
49  @InterfaceStability.Stable
50  @Deprecated
51  public class FirstKeyValueMatchingQualifiersFilter extends FirstKeyOnlyFilter {
52  
53    private Set<byte []> qualifiers;
54  
55    /**
56     * Constructor which takes a set of columns. As soon as first KeyValue
57     * matching any of these columns is found, filter moves to next row.
58     * 
59     * @param qualifiers the set of columns to me matched.
60     */
61    public FirstKeyValueMatchingQualifiersFilter(Set<byte []> qualifiers) {
62      this.qualifiers = qualifiers;
63    }
64  
65    @Override
66    public ReturnCode filterKeyValue(Cell v) {
67      if (hasFoundKV()) {
68        return ReturnCode.NEXT_ROW;
69      } else if (hasOneMatchingQualifier(v)) {
70        setFoundKV(true);
71      }
72      return ReturnCode.INCLUDE;
73    }
74  
75    private boolean hasOneMatchingQualifier(Cell v) {
76      for (byte[] q : qualifiers) {
77        if (CellUtil.matchingQualifier(v, q)) {
78          return true;
79        }
80      }
81      return false;
82    }
83  
84    /**
85     * @return The filter serialized using pb
86     */
87    public byte [] toByteArray() {
88      FilterProtos.FirstKeyValueMatchingQualifiersFilter.Builder builder =
89        FilterProtos.FirstKeyValueMatchingQualifiersFilter.newBuilder();
90      for (byte[] qualifier : qualifiers) {
91        if (qualifier != null) builder.addQualifiers(ByteStringer.wrap(qualifier));
92      }
93      return builder.build().toByteArray();
94    }
95  
96    /**
97     * @param pbBytes A pb serialized {@link FirstKeyValueMatchingQualifiersFilter} instance
98     * @return An instance of {@link FirstKeyValueMatchingQualifiersFilter} made from <code>bytes</code>
99     * @throws DeserializationException
100    * @see #toByteArray
101    */
102   public static FirstKeyValueMatchingQualifiersFilter parseFrom(final byte [] pbBytes)
103   throws DeserializationException {
104     FilterProtos.FirstKeyValueMatchingQualifiersFilter proto;
105     try {
106       proto = FilterProtos.FirstKeyValueMatchingQualifiersFilter.parseFrom(pbBytes);
107     } catch (InvalidProtocolBufferException e) {
108       throw new DeserializationException(e);
109     }
110 
111     TreeSet<byte []> qualifiers = new TreeSet<byte []>(Bytes.BYTES_COMPARATOR);
112     for (ByteString qualifier : proto.getQualifiersList()) {
113       qualifiers.add(qualifier.toByteArray());
114     }
115     return new FirstKeyValueMatchingQualifiersFilter(qualifiers);
116   }
117 
118   /**
119    * @param other
120    * @return true if and only if the fields of the filter that are serialized
121    * are equal to the corresponding fields in other.  Used for testing.
122    */
123   boolean areSerializedFieldsEqual(Filter o) {
124     if (o == this) return true;
125     if (!(o instanceof FirstKeyValueMatchingQualifiersFilter)) return false;
126 
127     FirstKeyValueMatchingQualifiersFilter other = (FirstKeyValueMatchingQualifiersFilter)o;
128     return this.qualifiers.equals(other.qualifiers);
129   }
130 }