org.apache.hadoop.mapred.lib.aggregate
Interface ValueAggregator

All Known Implementing Classes:

DoubleValueSum, LongValueMax, LongValueMin, LongValueSum, StringValueMax, StringValueMin, UniqValueCount, ValueHistogram

public interface ValueAggregator

This interface defines the minimal protocol for value aggregators.

Method Summary

void	addNextValue(Object val) add a value to the aggregator
ArrayList	getCombinerOutput()
String	getReport()
void	reset() reset the aggregator

Method Detail

addNextValue

void addNextValue(Object val)

add a value to the aggregator

Parameters:

val - the value to be added

reset

void reset()

reset the aggregator

getReport

String getReport()

Returns:

the string representation of the agregator

getCombinerOutput

ArrayList getCombinerOutput()

Returns:

an array of values as the outputs of the combiner.