com.datadoghq.sketch.ddsketch

Class SignedDDSketch

java.lang.Object

com.datadoghq.sketch.ddsketch.SignedDDSketch

All Implemented Interfaces:

QuantileSketch<SignedDDSketch>, java.util.function.DoubleConsumer

public class SignedDDSketch
extends java.lang.Object
implements QuantileSketch<SignedDDSketch>

A QuantileSketch with the same relative-error guarantees as DDSketch, but accepts both negative and positive input values.

As the negative value store is reversed, to collapse the lowest values its supplier should provide a CollapsingHighestDenseStore rather than a CollapsingLowestDenseStore.

Constructor Summary

Constructors

Constructor and Description
SignedDDSketch(IndexMapping indexMapping, java.util.function.Supplier<Store> storeSupplier) Constructs an initially empty quantile sketch using the specified IndexMapping and Store supplier.
SignedDDSketch(IndexMapping indexMapping, java.util.function.Supplier<Store> negativeValueStoreSupplier, java.util.function.Supplier<Store> positiveValueStoreSupplier) Constructs an initially empty quantile sketch using the specified IndexMapping and Store suppliers.
SignedDDSketch(IndexMapping indexMapping, java.util.function.Supplier<Store> negativeValueStoreSupplier, java.util.function.Supplier<Store> positiveValueStoreSupplier, double minIndexedValue) Constructs an initially empty quantile sketch using the specified IndexMapping and Store supplier.

Method Summary

Modifier and Type	Method and Description
void	accept(double value) Adds a value to the sketch.
void	accept(double value, double count) Adds a value to the sketch with a floating-point count.
void	accept(double value, long count) Adds a value to the sketch as many times as specified by count.
SignedDDSketch	copy()
static SignedDDSketch	fromProto(java.util.function.Supplier<? extends Store> storeSupplier, com.datadoghq.sketch.ddsketch.proto.DDSketch proto) Builds a new instance of SignedDDSketch based on the provided protobuf representation.
double	getCount()
IndexMapping	getIndexMapping()
double	getMaxValue()
double	getMinValue()
Store	getNegativeValueStore()
Store	getPositiveValueStore()
double	getValueAtQuantile(double quantile)
double[]	getValuesAtQuantiles(double[] quantiles)
boolean	isEmpty()
void	mergeWith(SignedDDSketch other) Merges the other sketch into this one.
com.datadoghq.sketch.ddsketch.proto.DDSketch	toProto() Generates a protobuf representation of this SignedDDSketch.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.function.DoubleConsumer

andThen

Constructor Detail

SignedDDSketch

public SignedDDSketch(IndexMapping indexMapping,
                      java.util.function.Supplier<Store> storeSupplier)

Constructs an initially empty quantile sketch using the specified IndexMapping and Store supplier.

Parameters:

indexMapping - the mapping between floating-point values and integer indices to be used by the sketch

storeSupplier - the store constructor for keeping track of added values

SignedDDSketch

public SignedDDSketch(IndexMapping indexMapping,
                      java.util.function.Supplier<Store> negativeValueStoreSupplier,
                      java.util.function.Supplier<Store> positiveValueStoreSupplier)

Constructs an initially empty quantile sketch using the specified IndexMapping and Store suppliers.

Parameters:

indexMapping - the mapping between floating-point values and integer indices to be used by the sketch

negativeValueStoreSupplier - the store constructor for keeping track of added negative values

positiveValueStoreSupplier - the store constructor for keeping track of added positive values

SignedDDSketch

public SignedDDSketch(IndexMapping indexMapping,
                      java.util.function.Supplier<Store> negativeValueStoreSupplier,
                      java.util.function.Supplier<Store> positiveValueStoreSupplier,
                      double minIndexedValue)

Constructs an initially empty quantile sketch using the specified IndexMapping and Store supplier.

Parameters:

indexMapping - the mapping between floating-point values and integer indices to be used by the sketch

negativeValueStoreSupplier - the store constructor for keeping track of added negative values

positiveValueStoreSupplier - the store constructor for keeping track of added positive values

minIndexedValue - the least value that should be distinguished from zero

Method Detail

getIndexMapping

public IndexMapping getIndexMapping()

getNegativeValueStore

public Store getNegativeValueStore()

getPositiveValueStore

public Store getPositiveValueStore()

accept

public void accept(double value)

Adds a value to the sketch.

Specified by:

accept in interface QuantileSketch<SignedDDSketch>

Specified by:

accept in interface java.util.function.DoubleConsumer

Parameters:

value - the value to be added

Throws:

java.lang.IllegalArgumentException - if the value is outside the range that is tracked by the sketch

accept

public void accept(double value,
                   long count)

Adds a value to the sketch as many times as specified by count.

Specified by:

accept in interface QuantileSketch<SignedDDSketch>

Parameters:

value - the value to be added

count - the number of times the value is to be added

Throws:

java.lang.IllegalArgumentException - if the value is outside the range that is tracked by the sketch

accept

public void accept(double value,
                   double count)

Adds a value to the sketch with a floating-point count.

Parameters:

value - the value to be added

count - the weight associated with the value to be added

Throws:

java.lang.IllegalArgumentException - if count is negative

mergeWith

public void mergeWith(SignedDDSketch other)

Merges the other sketch into this one. After this operation, this sketch encodes the values that were added to both this and the other sketches.

Specified by:

mergeWith in interface QuantileSketch<SignedDDSketch>

Parameters:

other - the sketch to be merged into this one

Throws:

java.lang.IllegalArgumentException - if the other sketch does not use the same index mapping

copy

public SignedDDSketch copy()

Specified by:

copy in interface QuantileSketch<SignedDDSketch>

Returns:

a (deep) copy of this sketch

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface QuantileSketch<SignedDDSketch>

Returns:

iff no value has been added to this sketch

getCount

public double getCount()

Specified by:

getCount in interface QuantileSketch<SignedDDSketch>

Returns:

the total number of values that have been added to this sketch

getMinValue

public double getMinValue()

Specified by:

getMinValue in interface QuantileSketch<SignedDDSketch>

Returns:

the minimum value that has been added to this sketch

getMaxValue

public double getMaxValue()

Specified by:

getMaxValue in interface QuantileSketch<SignedDDSketch>

Returns:

the maximum value that has been added to this sketch

getValueAtQuantile

public double getValueAtQuantile(double quantile)

Specified by:

getValueAtQuantile in interface QuantileSketch<SignedDDSketch>

Parameters:

quantile - a number between 0 and 1 (both included)

Returns:

the value at the specified quantile

getValuesAtQuantiles

public double[] getValuesAtQuantiles(double[] quantiles)

Specified by:

getValuesAtQuantiles in interface QuantileSketch<SignedDDSketch>

Parameters:

quantiles - number between 0 and 1 (both included)

Returns:

the values at the respective specified quantiles

toProto

public com.datadoghq.sketch.ddsketch.proto.DDSketch toProto()

Generates a protobuf representation of this SignedDDSketch.

Returns:

a protobuf representation of this SignedDDSketch

fromProto

public static SignedDDSketch fromProto(java.util.function.Supplier<? extends Store> storeSupplier,
                                       com.datadoghq.sketch.ddsketch.proto.DDSketch proto)

Builds a new instance of SignedDDSketch based on the provided protobuf representation.

Parameters:

storeSupplier - the constructor of the Store implementation to be used for encoding bin counters

proto - the protobuf representation of a sketch

Returns:

an instance of DDSketch that matches the protobuf representation