io.druid.query.aggregation.datasketches.theta

Class SketchAggregatorFactory

java.lang.Object

io.druid.query.aggregation.datasketches.theta.SketchAggregatorFactory

All Implemented Interfaces:

AggregatorFactory

Direct Known Subclasses:

SketchMergeAggregatorFactory

public abstract class SketchAggregatorFactory
extends Object
implements AggregatorFactory

Field Summary

Fields

Modifier and Type	Field and Description
static Comparator<com.yahoo.sketches.theta.Sketch>	COMPARATOR
static int	DEFAULT_MAX_SKETCH_SIZE
protected String	fieldName
protected String	name
protected int	size

Constructor Summary

Constructors

Constructor and Description
SketchAggregatorFactory(String name, String fieldName, Integer size, byte cacheId)

Method Summary

Modifier and Type	Method and Description
Object	combine(Object lhs, Object rhs) A method that knows how to combine the outputs of the getIntermediate() method from the Aggregators produced via factorize().
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)
Aggregator	factorize(ColumnSelectorFactory metricFactory)
BufferAggregator	factorizeBuffered(ColumnSelectorFactory metricFactory)
Object	getAggregatorStartValue() Returns the starting value for a corresponding aggregator.
byte[]	getCacheKey()
Comparator<com.yahoo.sketches.theta.Sketch>	getComparator()
String	getFieldName()
int	getMaxIntermediateSize() Returns the maximum size that this aggregator will require in bytes for intermediate storage of results.
String	getName()
int	getSize()
int	hashCode()
List<String>	requiredFields()
String	toString()

Methods inherited from class java.lang.Object

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

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

finalizeComputation, getCombiningFactory, getRequiredColumns, getTypeName

Field Detail

DEFAULT_MAX_SKETCH_SIZE

public static final int DEFAULT_MAX_SKETCH_SIZE

See Also:

Constant Field Values

name

protected final String name

fieldName

protected final String fieldName

size

protected final int size

COMPARATOR

public static final Comparator<com.yahoo.sketches.theta.Sketch> COMPARATOR

Constructor Detail

SketchAggregatorFactory

public SketchAggregatorFactory(String name,
                               String fieldName,
                               Integer size,
                               byte cacheId)

Method Detail

factorize

public Aggregator factorize(ColumnSelectorFactory metricFactory)

Specified by:

factorize in interface AggregatorFactory

factorizeBuffered

public BufferAggregator factorizeBuffered(ColumnSelectorFactory metricFactory)

Specified by:

factorizeBuffered in interface AggregatorFactory

deserialize

public Object deserialize(Object object)

Description copied from interface: 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 interface AggregatorFactory

Parameters:

object - the object to deserialize

Returns:

the deserialized object

getComparator

public Comparator<com.yahoo.sketches.theta.Sketch> getComparator()

Specified by:

getComparator in interface AggregatorFactory

combine

public Object combine(Object lhs,
                      Object rhs)

Description copied from interface: AggregatorFactory

A method that knows how to combine the outputs of the getIntermediate() method from the Aggregators produced via factorize(). Note, even though this 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 interface 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

getName

public String getName()

Specified by:

getName in interface AggregatorFactory

getFieldName

public String getFieldName()

getSize

public int getSize()

getMaxIntermediateSize

public int getMaxIntermediateSize()

Description copied from interface: AggregatorFactory

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

Specified by:

getMaxIntermediateSize in interface AggregatorFactory

Returns:

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

getAggregatorStartValue

public Object getAggregatorStartValue()

Description copied from interface: AggregatorFactory

Returns the starting value for a corresponding aggregator. For example, 0 for sums, - Infinity for max, an empty mogrifier

Specified by:

getAggregatorStartValue in interface AggregatorFactory

Returns:

the starting value for a corresponding aggregator.

requiredFields

public List<String> requiredFields()

Specified by:

requiredFields in interface AggregatorFactory

getCacheKey

public byte[] getCacheKey()

Specified by:

getCacheKey in interface AggregatorFactory

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object