com.wavefront.sdk.entities.histograms

Class WavefrontHistogramImpl

java.lang.Object

com.wavefront.sdk.entities.histograms.WavefrontHistogramImpl

public class WavefrontHistogramImpl
extends Object

Wavefront implementation of a histogram

Author:

Sushant Dewan (sushant@wavefront.com).

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	WavefrontHistogramImpl.Distribution Representation of a histogram distribution, containing a timestamp and a list of centroids.
static class	WavefrontHistogramImpl.Snapshot Wrapper for TDigest distribution

Constructor Summary

Constructors

Constructor and Description
WavefrontHistogramImpl()
WavefrontHistogramImpl(Supplier<Long> clockMillis)

Method Summary

Modifier and Type	Method and Description
void	bulkUpdate(List<Double> means, List<Integer> counts) Bulk-update this histogram with a set of centroids.
List<WavefrontHistogramImpl.Distribution>	flushDistributions() Aggregates all the minute bins prior to the current minute (because threads might be updating the current minute bin while the method is invoked) and returns a list of the distributions held within each bin.
long	getCount()
double	getMax()
double	getMean()
double	getMin()
WavefrontHistogramImpl.Snapshot	getSnapshot()
double	getSum()
double	stdDev()
void	update(double value)
void	update(int value)
void	update(long value)

Methods inherited from class java.lang.Object

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

Constructor Detail

WavefrontHistogramImpl

public WavefrontHistogramImpl()

WavefrontHistogramImpl

public WavefrontHistogramImpl(Supplier<Long> clockMillis)

Method Detail

update

public void update(int value)

update

public void update(long value)

update

public void update(double value)

bulkUpdate

public void bulkUpdate(List<Double> means,
                       List<Integer> counts)

Bulk-update this histogram with a set of centroids.

Parameters:

means - the centroid values

counts - the centroid weights/sample counts

getCount

public long getCount()

Returns:

returns the number of values in the distribution.

getMax

public double getMax()

Returns:

returns the maximum value in the distribution. Returns NaN if the distribution is empty.

getMin

public double getMin()

Returns:

returns the minimum value in the distribution. Returns NaN if the distribution is empty.

getMean

public double getMean()

Returns:

returns the mean of the values in the distribution. Returns NaN if the distribution is empty.

getSum

public double getSum()

Returns:

returns the sum of the values in the distribution.

stdDev

public double stdDev()

Returns:

returns the stdDev of the values in the distribution

flushDistributions

public List<WavefrontHistogramImpl.Distribution> flushDistributions()

Aggregates all the minute bins prior to the current minute (because threads might be updating the current minute bin while the method is invoked) and returns a list of the distributions held within each bin. Note that invoking this method will also clear all data from the aggregated bins, thereby changing the state of the system and preventing data from being flushed more than once.

Returns:

returns a list of distributions, each a WavefrontHistogramImpl.Distribution holding a timestamp as well as a list of centroids. Each centroid is a tuple containing the centroid value and count.

getSnapshot

public WavefrontHistogramImpl.Snapshot getSnapshot()

Returns:

returns a statistical WavefrontHistogramImpl.Snapshot of the histogram distribution.