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(java.lang.Object val) add a value to the aggregator
java.util.ArrayList	getCombinerOutput()
java.lang.String	getReport()
void	reset() reset the aggregator

Method Detail

addNextValue

void addNextValue(java.lang.Object val)

add a value to the aggregator

Parameters:

val - the value to be added

reset

void reset()

reset the aggregator

getReport

java.lang.String getReport()

Returns:

the string representation of the agregator

getCombinerOutput

java.util.ArrayList getCombinerOutput()

Returns:

an array of values as the outputs of the combiner.