datafu.hourglass.mapreduce
Class PartitioningCombiner

java.lang.Object
  datafu.hourglass.mapreduce.ObjectProcessor
      datafu.hourglass.mapreduce.ObjectReducer
          datafu.hourglass.mapreduce.PartitioningCombiner

All Implemented Interfaces:

java.io.Serializable

public class PartitioningCombiner
extends ObjectReducer
implements java.io.Serializable

The combiner used by AbstractPartitionPreservingIncrementalJob and its derived classes.

An implementation of Accumulator is used to perform aggregation and produce the intermediate value.

Author:

"Matthew Hayes"

See Also:

Serialized Form

Constructor Summary

PartitioningCombiner()

Method Summary

Accumulator<org.apache.avro.generic.GenericRecord,org.apache.avro.generic.GenericRecord>	getAccumulator() Gets the accumulator used to perform aggregation.
void	reduce(java.lang.Object keyObj, java.lang.Iterable<java.lang.Object> values, org.apache.hadoop.mapreduce.ReduceContext<java.lang.Object,java.lang.Object,java.lang.Object,java.lang.Object> context)
void	setAccumulator(Accumulator<org.apache.avro.generic.GenericRecord,org.apache.avro.generic.GenericRecord> acc) Sets the accumulator used to perform aggregation.

Methods inherited from class datafu.hourglass.mapreduce.ObjectProcessor

close, getContext, setContext

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PartitioningCombiner

public PartitioningCombiner()

Method Detail

reduce

public void reduce(java.lang.Object keyObj,
                   java.lang.Iterable<java.lang.Object> values,
                   org.apache.hadoop.mapreduce.ReduceContext<java.lang.Object,java.lang.Object,java.lang.Object,java.lang.Object> context)
            throws java.io.IOException,
                   java.lang.InterruptedException

Specified by:

reduce in class ObjectReducer

Throws:

java.io.IOException

java.lang.InterruptedException

getAccumulator

public Accumulator<org.apache.avro.generic.GenericRecord,org.apache.avro.generic.GenericRecord> getAccumulator()

Gets the accumulator used to perform aggregation.

Returns:

The accumulator

setAccumulator

public void setAccumulator(Accumulator<org.apache.avro.generic.GenericRecord,org.apache.avro.generic.GenericRecord> acc)

Sets the accumulator used to perform aggregation.

Parameters:

acc - The accumulator