org.apache.accumulo.core.iterators.user
Class MinCombiner

java.lang.Object
  extended by org.apache.accumulo.core.iterators.WrappingIterator
      extended by org.apache.accumulo.core.iterators.Combiner
          extended by org.apache.accumulo.core.iterators.TypedValueCombiner<Long>
              extended by org.apache.accumulo.core.iterators.LongCombiner
                  extended by org.apache.accumulo.core.iterators.user.MinCombiner
All Implemented Interfaces:
OptionDescriber, SortedKeyValueIterator<Key,Value>

public class MinCombiner
extends LongCombiner

A Combiner that interprets Values as Longs and returns the smallest Long among them.


Nested Class Summary
 
Nested classes/interfaces inherited from class org.apache.accumulo.core.iterators.LongCombiner
LongCombiner.FixedLenEncoder, LongCombiner.StringEncoder, LongCombiner.Type, LongCombiner.VarLenEncoder
 
Nested classes/interfaces inherited from class org.apache.accumulo.core.iterators.TypedValueCombiner
TypedValueCombiner.Encoder<V>
 
Nested classes/interfaces inherited from class org.apache.accumulo.core.iterators.Combiner
Combiner.ValueIterator
 
Nested classes/interfaces inherited from interface org.apache.accumulo.core.iterators.OptionDescriber
OptionDescriber.IteratorOptions
 
Field Summary
 
Fields inherited from class org.apache.accumulo.core.iterators.LongCombiner
CLASS_PREFIX, FIXED_LEN_ENCODER, STRING_ENCODER, TYPE, VAR_LEN_ENCODER
 
Fields inherited from class org.apache.accumulo.core.iterators.TypedValueCombiner
LOSSY
 
Fields inherited from class org.apache.accumulo.core.iterators.Combiner
ALL_OPTION, COLUMNS_OPTION
 
Constructor Summary
MinCombiner()
           
 
Method Summary
 OptionDescriber.IteratorOptions describeOptions()
          Gets an iterator options object that contains information needed to configure this iterator.
 Long typedReduce(Key key, Iterator<Long> iter)
          Reduces a list of V into a single V.
 
Methods inherited from class org.apache.accumulo.core.iterators.LongCombiner
init, safeAdd, setEncodingType, setEncodingType, setEncodingType, validateOptions
 
Methods inherited from class org.apache.accumulo.core.iterators.TypedValueCombiner
deepCopy, reduce, setEncoder, setEncoder, setLossyness, testEncoder, testEncoder
 
Methods inherited from class org.apache.accumulo.core.iterators.Combiner
getTopKey, getTopValue, hasTop, next, seek, setColumns, setCombineAllColumns
 
Methods inherited from class org.apache.accumulo.core.iterators.WrappingIterator
getSource, setSource
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

MinCombiner

public MinCombiner()
Method Detail

typedReduce

public Long typedReduce(Key key,
                        Iterator<Long> iter)
Description copied from class: TypedValueCombiner
Reduces a list of V into a single V.

Specified by:
typedReduce in class TypedValueCombiner<Long>
Parameters:
key - The most recent version of the Key being reduced.
iter - An iterator over the V for different versions of the key.
Returns:
The combined V.

describeOptions

public OptionDescriber.IteratorOptions describeOptions()
Description copied from interface: OptionDescriber
Gets an iterator options object that contains information needed to configure this iterator. This object will be used by the accumulo shell to prompt the user to input the appropriate information.

Specified by:
describeOptions in interface OptionDescriber
Overrides:
describeOptions in class LongCombiner
Returns:
an iterator options object


Copyright © 2012 The Apache Software Foundation. All Rights Reserved.