This project has retired. For details please refer to its
Attic page .
CombineFn.AggregatorCombineFn (Apache Crunch 0.7.0 API)
org.apache.crunch
Class CombineFn.AggregatorCombineFn<K,V>
java.lang.Object
org.apache.crunch.DoFn <Pair <S,Iterable <T>>,Pair <S,T>>
org.apache.crunch.CombineFn <K,V>
org.apache.crunch.CombineFn.AggregatorCombineFn<K,V>
All Implemented Interfaces: Serializable
Enclosing class: CombineFn <S ,T >
Deprecated. Use the Aggregators.toCombineFn(org.apache.crunch.Aggregator)
adapter
public static class CombineFn.AggregatorCombineFn<K,V> extends CombineFn <K,V>
A CombineFn
that delegates all of the actual work to an
Aggregator
instance.
See Also: Serialized Form
Nested classes/interfaces inherited from class org.apache.crunch.CombineFn
CombineFn.Aggregator <T >, CombineFn.AggregatorCombineFn <K ,V >, CombineFn.AggregatorFactory <T >, CombineFn.FirstNAggregator <V >, CombineFn.LastNAggregator <V >, CombineFn.MaxBigInts , CombineFn.MaxDoubles , CombineFn.MaxFloats , CombineFn.MaxInts , CombineFn.MaxLongs , CombineFn.MaxNAggregator <V extends Comparable <V >>, CombineFn.MinBigInts , CombineFn.MinDoubles , CombineFn.MinFloats , CombineFn.MinInts , CombineFn.MinLongs , CombineFn.MinNAggregator <V extends Comparable <V >>, CombineFn.PairAggregator <V1 ,V2 >, CombineFn.QuadAggregator <A ,B ,C ,D >, CombineFn.SimpleAggregator <T >, CombineFn.StringConcatAggregator , CombineFn.SumBigInts , CombineFn.SumDoubles , CombineFn.SumFloats , CombineFn.SumInts , CombineFn.SumLongs , CombineFn.TripAggregator <A ,B ,C >, CombineFn.TupleNAggregator
Fields inherited from class org.apache.crunch.CombineFn
MAX_BIGINTS , MAX_DOUBLES , MAX_FLOATS , MAX_INTS , MAX_LONGS , MIN_BIGINTS , MIN_DOUBLES , MIN_FLOATS , MIN_INTS , MIN_LONGS , SUM_BIGINTS , SUM_DOUBLES , SUM_FLOATS , SUM_INTS , SUM_LONGS
Methods inherited from class org.apache.crunch.CombineFn
aggregator , aggregatorFactory , FIRST_N , LAST_N , MAX_BIGINTS , MAX_BIGINTS , MAX_DOUBLES , MAX_DOUBLES , MAX_FLOATS , MAX_FLOATS , MAX_INTS , MAX_INTS , MAX_LONGS , MAX_LONGS , MIN_BIGINTS , MIN_BIGINTS , MIN_DOUBLES , MIN_DOUBLES , MIN_FLOATS , MIN_FLOATS , MIN_INTS , MIN_INTS , MIN_LONGS , MIN_LONGS , pairAggregator , quadAggregator , STRING_CONCAT , STRING_CONCAT , SUM_BIGINTS , SUM_DOUBLES , SUM_FLOATS , SUM_INTS , SUM_LONGS , tripAggregator , tupleAggregator
CombineFn.AggregatorCombineFn
public CombineFn.AggregatorCombineFn (CombineFn.Aggregator <V > aggregator)
Deprecated.
initialize
public void initialize ()
Deprecated. Description copied from class: DoFn
Initialize this DoFn. This initialization will happen before the actual
DoFn.process(Object, Emitter)
is triggered. Subclasses may override
this method to do appropriate initialization.
Called during the setup of the job instance this DoFn
is associated
with.
Overrides: initialize
in class DoFn <Pair <K ,Iterable <V >>,Pair <K ,V >>
process
public void process (Pair <K ,Iterable <V >> input,
Emitter <Pair <K ,V >> emitter)
Deprecated. Description copied from class: DoFn
Processes the records from a PCollection
.
Note: Crunch can reuse a single input record object whose content
changes on each DoFn.process(Object, Emitter)
method call. This
functionality is imposed by Hadoop's Reducer implementation: The framework will reuse the key and value
objects that are passed into the reduce, therefore the application should
clone the objects they want to keep a copy of.
Specified by: process
in class DoFn <Pair <K ,Iterable <V >>,Pair <K ,V >>
Parameters: input
- The input record.emitter
- The emitter to send the output to
Copyright © 2013 The Apache Software Foundation . All Rights Reserved.