View Javadoc

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 java.util.ArrayList;
24  
25  import org.apache.hadoop.hbase.KeyValue;
26  import org.apache.hadoop.hbase.client.Scan;
27  
28  /**
29   * This filter is used to filter based on the key. It takes an operator
30   * (equal, greater, not equal, etc) and a byte [] comparator for the row,
31   * and column qualifier portions of a key.
32   * <p>
33   * This filter can be wrapped with {@link WhileMatchFilter} to add more control.
34   * <p>
35   * Multiple filters can be combined using {@link FilterList}.
36   * <p>
37   * If an already known row range needs to be scanned, use {@link Scan} start
38   * and stop rows directly rather than a filter.
39   */
40  public class RowFilter extends CompareFilter {
41  
42    private boolean filterOutRow = false;
43  
44    /**
45     * Writable constructor, do not use.
46     */
47    public RowFilter() {
48      super();
49    }
50  
51    /**
52     * Constructor.
53     * @param rowCompareOp the compare op for row matching
54     * @param rowComparator the comparator for row matching
55     */
56    public RowFilter(final CompareOp rowCompareOp,
57        final WritableByteArrayComparable rowComparator) {
58      super(rowCompareOp, rowComparator);
59    }
60  
61    @Override
62    public void reset() {
63      this.filterOutRow = false;
64    }
65  
66    @Override
67    public ReturnCode filterKeyValue(KeyValue v) {
68      if(this.filterOutRow) {
69        return ReturnCode.NEXT_ROW;
70      }
71      return ReturnCode.INCLUDE;
72    }
73  
74    @Override
75    public boolean filterRowKey(byte[] data, int offset, int length) {
76      if(doCompare(this.compareOp, this.comparator, data, offset, length)) {
77        this.filterOutRow = true;
78      }
79      return this.filterOutRow;
80    }
81  
82    @Override
83    public boolean filterRow() {
84      return this.filterOutRow;
85    }
86  
87    public static Filter createFilterFromArguments(ArrayList<byte []> filterArguments) {
88      ArrayList arguments = CompareFilter.extractArguments(filterArguments);
89      CompareOp compareOp = (CompareOp)arguments.get(0);
90      WritableByteArrayComparable comparator = (WritableByteArrayComparable)arguments.get(1);
91      return new RowFilter(compareOp, comparator);
92    }
93  }