Package org.apache.pinot.segment.local.customobject

Class QuantileDigest

java.lang.Object

org.apache.pinot.segment.local.customobject.QuantileDigest

public class QuantileDigest
extends Object

Re-implement io.airlift.stats.QuantileDigest with additional methods facilitating serialization.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	QuantileDigest.Bucket

Constructor Summary

Constructors

Constructor	Description
QuantileDigest(double maxError)	Create a QuantileDigest with a maximum error guarantee of "maxError" and no decay.
QuantileDigest(double maxError, double alpha)	Create a QuantileDigest with a maximum error guarantee of "maxError" and exponential decay with factor "alpha".
QuantileDigest(QuantileDigest quantileDigest)

Method Summary

Modifier and Type	Method	Description
void	add(long value)
void	add(long value, long count)	Adds a value to this digest.
boolean	equivalent(QuantileDigest other)
static <T> T	firstNonNull(T first, T second)
static QuantileDigest	fromByteBuffer(ByteBuffer byteBuffer)
static QuantileDigest	fromBytes(byte[] bytes)
double	getAlpha()
int	getByteSize()
double	getConfidenceFactor()	Computes the maximum error of the current digest
double	getCount()	Number (decayed) of elements added to this quantile digest
List<QuantileDigest.Bucket>	getHistogram(List<Long> bucketUpperBounds)
long	getMax()
double	getMaxError()
long	getMin()
long	getQuantile(double quantile)	Gets the value at the specified quantile +/- maxError.
List<Long>	getQuantiles(List<Double> quantiles)	Gets the values at the specified quantiles +/- maxError.
static QuantileDigest	merge(List<QuantileDigest> digests)
void	merge(QuantileDigest other)
void	offer(long value)
byte[]	toBytes()
String	toGraphviz()

Methods inherited from class java.lang.Object

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

Constructor Detail

QuantileDigest

public QuantileDigest(double maxError)

Create a QuantileDigest with a maximum error guarantee of "maxError" and no decay.

Parameters:

maxError - the max error tolerance

QuantileDigest

public QuantileDigest(double maxError,
                      double alpha)

Create a QuantileDigest with a maximum error guarantee of "maxError" and exponential decay with factor "alpha".

Parameters:

maxError - the max error tolerance

alpha - the exponential decay factor

QuantileDigest

public QuantileDigest(QuantileDigest quantileDigest)

Method Detail

getMaxError

public double getMaxError()

getAlpha

public double getAlpha()

add

public void add(long value)

add

public void add(long value,
                long count)

Adds a value to this digest. The value must be >= 0

merge

public void merge(QuantileDigest other)

getQuantiles

public List<Long> getQuantiles(List<Double> quantiles)

Gets the values at the specified quantiles +/- maxError. The list of quantiles must be sorted in increasing order, and each value must be in the range [0, 1]

getQuantile

public long getQuantile(double quantile)

Gets the value at the specified quantile +/- maxError. The quantile must be in the range [0, 1]

getCount

public double getCount()

Number (decayed) of elements added to this quantile digest

getHistogram

public List<QuantileDigest.Bucket> getHistogram(List<Long> bucketUpperBounds)

getMin

public long getMin()

getMax

public long getMax()

getByteSize

public int getByteSize()

toBytes

public byte[] toBytes()

fromBytes

public static QuantileDigest fromBytes(byte[] bytes)

fromByteBuffer

public static QuantileDigest fromByteBuffer(ByteBuffer byteBuffer)

getConfidenceFactor

public double getConfidenceFactor()

Computes the maximum error of the current digest

equivalent

public boolean equivalent(QuantileDigest other)

toGraphviz

public String toGraphviz()

firstNonNull

public static <T> T firstNonNull(T first,
                                 T second)

offer

public void offer(long value)

merge

public static QuantileDigest merge(List<QuantileDigest> digests)