io.druid.query.aggregation

Class DoubleMaxAggregatorFactory

java.lang.Object

io.druid.query.aggregation.AggregatorFactory

io.druid.query.aggregation.SimpleDoubleAggregatorFactory

io.druid.query.aggregation.DoubleMaxAggregatorFactory

All Implemented Interfaces:

Cacheable

public class DoubleMaxAggregatorFactory
extends SimpleDoubleAggregatorFactory

Field Summary

Fields inherited from class io.druid.query.aggregation.SimpleDoubleAggregatorFactory

expression, fieldName, macroTable, name, storeDoubleAsFloat

Constructor Summary

Constructors

Constructor and Description
DoubleMaxAggregatorFactory(String name, String fieldName)
DoubleMaxAggregatorFactory(String name, String fieldName, String expression, ExprMacroTable macroTable)

Method Summary

Modifier and Type	Method and Description
Object	combine(Object lhs, Object rhs) A method that knows how to combine the outputs of Aggregator.get() produced via AggregatorFactory.factorize(io.druid.segment.ColumnSelectorFactory) or BufferAggregator.get(java.nio.ByteBuffer, int) produced via AggregatorFactory.factorizeBuffered(io.druid.segment.ColumnSelectorFactory).
Aggregator	factorize(ColumnSelectorFactory metricFactory)
BufferAggregator	factorizeBuffered(ColumnSelectorFactory metricFactory)
Object	finalizeComputation(Object object) "Finalizes" the computation of an object.
byte[]	getCacheKey() Get a byte array used as a cache key.
AggregatorFactory	getCombiningFactory() Returns an AggregatorFactory that can be used to combine the output of aggregators from this factory.
List<AggregatorFactory>	getRequiredColumns() Gets a list of all columns that this AggregatorFactory will scan
AggregateCombiner	makeAggregateCombiner() Creates an AggregateCombiner to fold rollup aggregation results from serveral "rows" of different indexes during index merging.
String	toString()

Methods inherited from class io.druid.query.aggregation.SimpleDoubleAggregatorFactory

deserialize, equals, getComparator, getDoubleColumnSelector, getExpression, getFieldName, getMaxIntermediateSize, getMergingFactory, getName, getTypeName, hashCode, requiredFields

Methods inherited from class io.druid.query.aggregation.AggregatorFactory

mergeAggregators

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

DoubleMaxAggregatorFactory

public DoubleMaxAggregatorFactory(String name,
                                  String fieldName,
                                  String expression,
                                  ExprMacroTable macroTable)

DoubleMaxAggregatorFactory

public DoubleMaxAggregatorFactory(String name,
                                  String fieldName)

Method Detail

factorize

public Aggregator factorize(ColumnSelectorFactory metricFactory)

Specified by:

factorize in class AggregatorFactory

factorizeBuffered

public BufferAggregator factorizeBuffered(ColumnSelectorFactory metricFactory)

Specified by:

factorizeBuffered in class AggregatorFactory

combine

public Object combine(Object lhs,
                      Object rhs)

Description copied from class: AggregatorFactory

A method that knows how to combine the outputs of Aggregator.get() produced via AggregatorFactory.factorize(io.druid.segment.ColumnSelectorFactory) or BufferAggregator.get(java.nio.ByteBuffer, int) produced via AggregatorFactory.factorizeBuffered(io.druid.segment.ColumnSelectorFactory). Note, even though this method is called "combine", this method's contract *does* allow for mutation of the input objects. Thus, any use of lhs or rhs after calling this method is highly discouraged.

Specified by:

combine in class AggregatorFactory

Parameters:

lhs - The left hand side of the combine

rhs - The right hand side of the combine

Returns:

an object representing the combination of lhs and rhs, this can be a new object or a mutation of the inputs

makeAggregateCombiner

public AggregateCombiner makeAggregateCombiner()

Description copied from class: AggregatorFactory

Creates an AggregateCombiner to fold rollup aggregation results from serveral "rows" of different indexes during index merging. AggregateCombiner implements the same logic as AggregatorFactory.combine(java.lang.Object, java.lang.Object), with the difference that it uses ColumnValueSelector and it's subinterfaces to get inputs and implements ColumnValueSelector to provide output.

Overrides:

makeAggregateCombiner in class AggregatorFactory

See Also:

AggregateCombiner, IndexMerger

getCombiningFactory

public AggregatorFactory getCombiningFactory()

Description copied from class: AggregatorFactory

Returns an AggregatorFactory that can be used to combine the output of aggregators from this factory. This generally amounts to simply creating a new factory that is the same as the current except with its input column renamed to the same as the output column.

Specified by:

getCombiningFactory in class AggregatorFactory

Returns:

a new Factory that can be used for operations on top of data output from the current factory.

getRequiredColumns

public List<AggregatorFactory> getRequiredColumns()

Description copied from class: AggregatorFactory

Gets a list of all columns that this AggregatorFactory will scan

Specified by:

getRequiredColumns in class AggregatorFactory

Returns:

AggregatorFactories for the columns to scan of the parent AggregatorFactory

finalizeComputation

public Object finalizeComputation(Object object)

Description copied from class: AggregatorFactory

"Finalizes" the computation of an object. Primarily useful for complex types that have a different mergeable intermediate format than their final resultant output.

Overrides:

finalizeComputation in class SimpleDoubleAggregatorFactory

Parameters:

object - the object to be finalized

Returns:

the finalized value that should be returned for the initial query

getCacheKey

public byte[] getCacheKey()

Description copied from interface: Cacheable

Get a byte array used as a cache key.

Returns:

a cache key

toString

public String toString()

Overrides:

toString in class Object