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 org.apache.hadoop.hbase.classification.InterfaceAudience;
22 import org.apache.hadoop.hbase.classification.InterfaceStability;
23 import org.apache.hadoop.hbase.Cell;
24 import org.apache.hadoop.hbase.CellUtil;
25 import org.apache.hadoop.hbase.exceptions.DeserializationException;
26 import org.apache.hadoop.hbase.protobuf.generated.FilterProtos;
27 import org.apache.hadoop.hbase.util.ByteStringer;
28 import org.apache.hadoop.hbase.util.Bytes;
29 
30 import com.google.protobuf.ByteString;
31 import com.google.protobuf.InvalidProtocolBufferException;
32 
33 import java.util.Set;
34 import java.util.TreeSet;
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  */
47 @InterfaceAudience.Public
48 @InterfaceStability.Stable
49 public class FirstKeyValueMatchingQualifiersFilter extends FirstKeyOnlyFilter {
50 
51   private Set<byte []> qualifiers;
52 
53   /**
54    * Constructor which takes a set of columns. As soon as first KeyValue
55    * matching any of these columns is found, filter moves to next row.
56    *
57    * @param qualifiers the set of columns to me matched.
58    */
FirstKeyValueMatchingQualifiersFilter(Set<byte []> qualifiers)59   public FirstKeyValueMatchingQualifiersFilter(Set<byte []> qualifiers) {
60     this.qualifiers = qualifiers;
61   }
62 
63   @Override
filterKeyValue(Cell v)64   public ReturnCode filterKeyValue(Cell v) {
65     if (hasFoundKV()) {
66       return ReturnCode.NEXT_ROW;
67     } else if (hasOneMatchingQualifier(v)) {
68       setFoundKV(true);
69     }
70     return ReturnCode.INCLUDE;
71   }
72 
hasOneMatchingQualifier(Cell v)73   private boolean hasOneMatchingQualifier(Cell v) {
74     for (byte[] q : qualifiers) {
75       if (CellUtil.matchingQualifier(v, q)) {
76         return true;
77       }
78     }
79     return false;
80   }
81 
82   /**
83    * @return The filter serialized using pb
84    */
toByteArray()85   public byte [] toByteArray() {
86     FilterProtos.FirstKeyValueMatchingQualifiersFilter.Builder builder =
87       FilterProtos.FirstKeyValueMatchingQualifiersFilter.newBuilder();
88     for (byte[] qualifier : qualifiers) {
89       if (qualifier != null) builder.addQualifiers(ByteStringer.wrap(qualifier));
90     }
91     return builder.build().toByteArray();
92   }
93 
94   /**
95    * @param pbBytes A pb serialized {@link FirstKeyValueMatchingQualifiersFilter} instance
96    * @return An instance of {@link FirstKeyValueMatchingQualifiersFilter} made from <code>bytes</code>
97    * @throws DeserializationException
98    * @see #toByteArray
99    */
parseFrom(final byte [] pbBytes)100   public static FirstKeyValueMatchingQualifiersFilter parseFrom(final byte [] pbBytes)
101   throws DeserializationException {
102     FilterProtos.FirstKeyValueMatchingQualifiersFilter proto;
103     try {
104       proto = FilterProtos.FirstKeyValueMatchingQualifiersFilter.parseFrom(pbBytes);
105     } catch (InvalidProtocolBufferException e) {
106       throw new DeserializationException(e);
107     }
108 
109     TreeSet<byte []> qualifiers = new TreeSet<byte []>(Bytes.BYTES_COMPARATOR);
110     for (ByteString qualifier : proto.getQualifiersList()) {
111       qualifiers.add(qualifier.toByteArray());
112     }
113     return new FirstKeyValueMatchingQualifiersFilter(qualifiers);
114   }
115 
116   /**
117    * @param other
118    * @return true if and only if the fields of the filter that are serialized
119    * are equal to the corresponding fields in other.  Used for testing.
120    */
areSerializedFieldsEqual(Filter o)121   boolean areSerializedFieldsEqual(Filter o) {
122     if (o == this) return true;
123     if (!(o instanceof FirstKeyValueMatchingQualifiersFilter)) return false;
124 
125     FirstKeyValueMatchingQualifiersFilter other = (FirstKeyValueMatchingQualifiersFilter)o;
126     return this.qualifiers.equals(other.qualifiers);
127   }
128 }
129