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1   /**
2    * Copyright The Apache Software Foundation
3    *
4    * Licensed to the Apache Software Foundation (ASF) under one or more
5    * contributor license agreements. See the NOTICE file distributed with this
6    * work for additional information regarding copyright ownership. The ASF
7    * licenses this file to you under the Apache License, Version 2.0 (the
8    * "License"); you may not use this file except in compliance with the License.
9    * 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, WITHOUT
15   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
16   * License for the specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.apache.hadoop.hbase.regionserver;
20  
21  import java.io.IOException;
22  
23  import org.apache.commons.lang.NotImplementedException;
24  import org.apache.hadoop.hbase.classification.InterfaceAudience;
25  import org.apache.hadoop.hbase.Cell;
26  
27  /**
28   * A "non-reversed & non-lazy" scanner which does not support backward scanning
29   * and always does a real seek operation. Most scanners are inherited from this
30   * class.
31   */
32  @InterfaceAudience.Private
33  public abstract class NonReversedNonLazyKeyValueScanner extends
34      NonLazyKeyValueScanner {
35  
36    @Override
37    public boolean backwardSeek(Cell key) throws IOException {
38      throw new NotImplementedException("backwardSeek must not be called on a "
39          + "non-reversed scanner");
40    }
41  
42    @Override
43    public boolean seekToPreviousRow(Cell key) throws IOException {
44      throw new NotImplementedException("seekToPreviousRow must not be called on a "
45          + "non-reversed scanner");
46    }
47  
48    @Override
49    public boolean seekToLastRow() throws IOException {
50      throw new NotImplementedException("seekToLastRow must not be called on a "
51          + "non-reversed scanner");
52    }
53  
54  }