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 import org.apache.hadoop.hbase.client.Get;
25
26 import java.util.ArrayList;
27
28 /**
29 * This filter is used to filter based on the column qualifier. It takes an
30 * operator (equal, greater, not equal, etc) and a byte [] comparator for the
31 * column qualifier portion of a key.
32 * <p>
33 * This filter can be wrapped with {@link WhileMatchFilter} and {@link SkipFilter}
34 * to add more control.
35 * <p>
36 * Multiple filters can be combined using {@link FilterList}.
37 * <p>
38 * If an already known column qualifier is looked for, use {@link Get#addColumn}
39 * directly rather than a filter.
40 */
41 public class QualifierFilter extends CompareFilter {
42
43 /**
44 * Writable constructor, do not use.
45 */
46 public QualifierFilter() {
47 }
48
49 /**
50 * Constructor.
51 * @param op the compare op for column qualifier matching
52 * @param qualifierComparator the comparator for column qualifier matching
53 */
54 public QualifierFilter(final CompareOp op,
55 final WritableByteArrayComparable qualifierComparator) {
56 super(op, qualifierComparator);
57 }
58
59 @Override
60 public ReturnCode filterKeyValue(KeyValue v) {
61 int qualifierLength = v.getQualifierLength();
62 if (qualifierLength > 0) {
63 if (doCompare(this.compareOp, this.comparator, v.getBuffer(),
64 v.getQualifierOffset(), qualifierLength)) {
65 return ReturnCode.SKIP;
66 }
67 }
68 return ReturnCode.INCLUDE;
69 }
70
71 public static Filter createFilterFromArguments(ArrayList<byte []> filterArguments) {
72 ArrayList arguments = CompareFilter.extractArguments(filterArguments);
73 CompareOp compareOp = (CompareOp)arguments.get(0);
74 WritableByteArrayComparable comparator = (WritableByteArrayComparable)arguments.get(1);
75 return new QualifierFilter(compareOp, comparator);
76 }
77 }