org.apache.druid.query.aggregation

Class SimpleDoubleAggregatorFactory

java.lang.Object

org.apache.druid.query.aggregation.AggregatorFactory

org.apache.druid.query.aggregation.NullableNumericAggregatorFactory<ColumnValueSelector>

org.apache.druid.query.aggregation.SimpleDoubleAggregatorFactory

All Implemented Interfaces:

Cacheable

Direct Known Subclasses:

DoubleMaxAggregatorFactory, DoubleMinAggregatorFactory, DoubleSumAggregatorFactory

public abstract class SimpleDoubleAggregatorFactory
extends NullableNumericAggregatorFactory<ColumnValueSelector>

This is an abstract class inherited by various AggregatorFactory implementations that consume double input and produce double output on aggregation. It extends "NullableAggregatorFactory" instead of "NullableAggregatorFactory" to additionally support aggregation on single/multi value string column types.

Field Summary

Fields

Modifier and Type	Field and Description
protected String	expression
protected com.google.common.base.Supplier<Expr>	fieldExpression
protected String	fieldName
protected ExprMacroTable	macroTable
protected String	name
protected boolean	storeDoubleAsFloat

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
protected abstract Aggregator	buildAggregator(BaseDoubleColumnValueSelector selector)
protected abstract BufferAggregator	buildBufferAggregator(BaseDoubleColumnValueSelector selector)
boolean	canVectorize(ColumnInspector columnInspector) Returns whether or not this aggregation class supports vectorization.
Object	deserialize(Object object) A method that knows how to "deserialize" the object from whatever form it might have been put into in order to transfer via JSON.
boolean	equals(Object o)
protected Aggregator	factorize(ColumnSelectorFactory metricFactory, ColumnValueSelector selector) Creates an Aggregator to aggregate values from several rows, by using the provided selector.
protected BufferAggregator	factorizeBuffered(ColumnSelectorFactory metricFactory, ColumnValueSelector selector) Creates an BufferAggregator to aggregate values from several rows into a ByteBuffer.
Object	finalizeComputation(Object object) "Finalizes" the computation of an object.
Comparator	getComparator()
String	getExpression()
String	getFieldName()
ColumnType	getIntermediateType() Get the "intermediate" ColumnType for this aggregator.
int	getMaxIntermediateSize() Returns the maximum size that this aggregator will require in bytes for intermediate storage of results.
AggregatorFactory	getMergingFactory(AggregatorFactory other) Returns an AggregatorFactory that can be used to combine the output of aggregators from this factory and another factory.
String	getName()
int	hashCode()
protected abstract double	nullValue()
List<String>	requiredFields() Get a list of fields that aggregators built by this factory will need to read.
protected ColumnValueSelector	selector(ColumnSelectorFactory metricFactory) Creates a ColumnValueSelector for the aggregated column.
protected VectorValueSelector	vectorSelector(VectorColumnSelectorFactory columnSelectorFactory) Creates a VectorValueSelector for the aggregated column.

Methods inherited from class org.apache.druid.query.aggregation.NullableNumericAggregatorFactory

factorize, factorizeBuffered, factorizeVector, factorizeVector, getMaxIntermediateSizeWithNulls, getResultType, makeNullableAggregateCombiner

Methods inherited from class org.apache.druid.query.aggregation.AggregatorFactory

combine, factorizeWithSize, getCombiningFactory, getComplexTypeName, getFinalizedType, getRequiredColumns, getType, guessAggregatorHeapFootprint, makeAggregateCombiner, mergeAggregators, optimizeForSegment, withName

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.druid.java.util.common.Cacheable

getCacheKey

Field Detail

name

protected final String name

fieldName

@Nullable
protected final String fieldName

expression

@Nullable
protected final String expression

macroTable

protected final ExprMacroTable macroTable

storeDoubleAsFloat

protected final boolean storeDoubleAsFloat

fieldExpression

protected final com.google.common.base.Supplier<Expr> fieldExpression

Constructor Detail

SimpleDoubleAggregatorFactory

public SimpleDoubleAggregatorFactory(ExprMacroTable macroTable,
                                     String name,
                                     @Nullable
                                     String fieldName,
                                     @Nullable
                                     String expression)

Method Detail

factorize

protected Aggregator factorize(ColumnSelectorFactory metricFactory,
                               ColumnValueSelector selector)

Description copied from class: NullableNumericAggregatorFactory

Creates an Aggregator to aggregate values from several rows, by using the provided selector.

Specified by:

factorize in class NullableNumericAggregatorFactory<ColumnValueSelector>

Parameters:

metricFactory - metricFactory

selector - ColumnValueSelector for the column to aggregate.

See Also:

Aggregator

factorizeBuffered

protected BufferAggregator factorizeBuffered(ColumnSelectorFactory metricFactory,
                                             ColumnValueSelector selector)

Description copied from class: NullableNumericAggregatorFactory

Creates an BufferAggregator to aggregate values from several rows into a ByteBuffer.

Specified by:

factorizeBuffered in class NullableNumericAggregatorFactory<ColumnValueSelector>

Parameters:

metricFactory - columnSelectorFactory in case any other columns are needed.

selector - ColumnValueSelector for the column to aggregate.

See Also:

BufferAggregator

selector

protected ColumnValueSelector selector(ColumnSelectorFactory metricFactory)

Description copied from class: NullableNumericAggregatorFactory

Creates a ColumnValueSelector for the aggregated column.

Specified by:

selector in class NullableNumericAggregatorFactory<ColumnValueSelector>

See Also:

ColumnValueSelector

vectorSelector

protected VectorValueSelector vectorSelector(VectorColumnSelectorFactory columnSelectorFactory)

Description copied from class: NullableNumericAggregatorFactory

Creates a VectorValueSelector for the aggregated column.

Overrides:

vectorSelector in class NullableNumericAggregatorFactory<ColumnValueSelector>

See Also:

VectorValueSelector

deserialize

public Object deserialize(Object object)

Description copied from class: AggregatorFactory

A method that knows how to "deserialize" the object from whatever form it might have been put into in order to transfer via JSON.

Specified by:

deserialize in class AggregatorFactory

Parameters:

object - the object to deserialize

Returns:

the deserialized object

getIntermediateType

public ColumnType getIntermediateType()

Description copied from class: AggregatorFactory

Get the "intermediate" ColumnType for this aggregator. This is the same as the type returned by AggregatorFactory.deserialize(java.lang.Object) and the type accepted by AggregatorFactory.combine(java.lang.Object, java.lang.Object). However, it is *not* necessarily the same type returned by AggregatorFactory.finalizeComputation(java.lang.Object). Refer to the ColumnType javadocs for details on the implications of choosing a type.

Overrides:

getIntermediateType in class AggregatorFactory

getMaxIntermediateSize

public int getMaxIntermediateSize()

Description copied from class: AggregatorFactory

Returns the maximum size that this aggregator will require in bytes for intermediate storage of results.

Specified by:

getMaxIntermediateSize in class AggregatorFactory

Returns:

the maximum number of bytes that an aggregator of this type will require for intermediate result storage.

getComparator

public Comparator getComparator()

Specified by:

getComparator in class AggregatorFactory

finalizeComputation

@Nullable
public Object finalizeComputation(@Nullable
                                            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.

Specified by:

finalizeComputation in class AggregatorFactory

Parameters:

object - the object to be finalized

Returns:

the finalized value that should be returned for the initial query

requiredFields

public List<String> requiredFields()

Description copied from class: AggregatorFactory

Get a list of fields that aggregators built by this factory will need to read.

Specified by:

requiredFields in class AggregatorFactory

getMergingFactory

public AggregatorFactory getMergingFactory(AggregatorFactory other)
                                    throws AggregatorFactoryNotMergeableException

Description copied from class: AggregatorFactory

Returns an AggregatorFactory that can be used to combine the output of aggregators from this factory and another factory. It is used when we have some values produced by this aggregator factory, and some values produced by the "other" aggregator factory, and we want to do some additional combining of them. This happens, for example, when compacting two segments together that both have a metric column with the same name. (Even though the name of the column is the same, the aggregator factory used to create it may be different from segment to segment.) This method may throw AggregatorFactoryNotMergeableException, meaning that "this" and "other" are not compatible and values from one cannot sensibly be combined with values from the other.

Overrides:

getMergingFactory in class AggregatorFactory

Returns:

a new Factory that can be used for merging the output of aggregators from this factory and other.

Throws:

AggregatorFactoryNotMergeableException

See Also:

which is equivalent to {@code foo.getMergingFactory(foo)} (when "this" and "other" are the same instance).

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class Object

getName

public String getName()

Specified by:

getName in class AggregatorFactory

Returns:

output name of the aggregator column.

getFieldName

@Nullable
public String getFieldName()

getExpression

@Nullable
public String getExpression()

canVectorize

public boolean canVectorize(ColumnInspector columnInspector)

Description copied from class: AggregatorFactory

Returns whether or not this aggregation class supports vectorization. The default implementation returns false.

Overrides:

canVectorize in class AggregatorFactory

nullValue

protected abstract double nullValue()

buildAggregator

protected abstract Aggregator buildAggregator(BaseDoubleColumnValueSelector selector)

buildBufferAggregator

protected abstract BufferAggregator buildBufferAggregator(BaseDoubleColumnValueSelector selector)