hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/NonReversedNonLazyKeyValueScanner.java

   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 &amp; 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 }