Package org.apache.druid.query.aggregation.cardinality.types

Class LongCardinalityAggregatorColumnSelectorStrategy

java.lang.Object

org.apache.druid.query.aggregation.cardinality.types.LongCardinalityAggregatorColumnSelectorStrategy

All Implemented Interfaces:

CardinalityAggregatorColumnSelectorStrategy<BaseLongColumnValueSelector>, ColumnSelectorStrategy

public class LongCardinalityAggregatorColumnSelectorStrategy
extends Object
implements CardinalityAggregatorColumnSelectorStrategy<BaseLongColumnValueSelector>

If performance of this class appears to be a bottleneck for somebody, one simple way to improve it is to split it into two different classes, one that is used when NullHandling.replaceWithDefault() is false, and one - when it's true, moving this computation out of the tight loop

Constructor Summary

Constructors

Constructor	Description
LongCardinalityAggregatorColumnSelectorStrategy()

Method Summary

Modifier and Type	Method	Description
static void	addLongToCollector(HyperLogLogCollector collector, long n)
void	hashRow(BaseLongColumnValueSelector selector, com.google.common.hash.Hasher hasher)	Retrieve the current row from dimSelector and add the row values to the hasher.
void	hashValues(BaseLongColumnValueSelector selector, HyperLogLogCollector collector)	Retrieve the current row from dimSelector and add the row values to HyperLogLogCollector.

Methods inherited from class java.lang.Object

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

Constructor Detail

LongCardinalityAggregatorColumnSelectorStrategy

public LongCardinalityAggregatorColumnSelectorStrategy()

Method Detail

addLongToCollector

public static void addLongToCollector(HyperLogLogCollector collector,
                                      long n)

hashRow

public void hashRow(BaseLongColumnValueSelector selector,
                    com.google.common.hash.Hasher hasher)

Description copied from interface: CardinalityAggregatorColumnSelectorStrategy

Retrieve the current row from dimSelector and add the row values to the hasher.

Specified by:

hashRow in interface CardinalityAggregatorColumnSelectorStrategy<BaseLongColumnValueSelector>

Parameters:

selector - Dimension value selector

hasher - Hasher used for cardinality aggregator calculations

hashValues

public void hashValues(BaseLongColumnValueSelector selector,
                       HyperLogLogCollector collector)

Description copied from interface: CardinalityAggregatorColumnSelectorStrategy

Retrieve the current row from dimSelector and add the row values to HyperLogLogCollector.

Specified by:

hashValues in interface CardinalityAggregatorColumnSelectorStrategy<BaseLongColumnValueSelector>

Parameters:

selector - Dimension value selector

collector - HLL collector used for cardinality aggregator calculations