Class Histogram

java.lang.Object

com.codename1.backend.metrics.Instrument

com.codename1.backend.metrics.Histogram

public final class Histogram
extends Instrument

A distribution of values -- durations, sizes -- kept as counts per bucket. Exported as a cumulative explicit-bucket histogram.

The buckets are fixed when the histogram is created; the default boundaries are OpenTelemetry's, which suit milliseconds.

A histogram created with label keys keeps a series per combination of label values -- the server's request histogram has route, method and status. The series are found by a map lookup on the first label, which is a constant such as a route template, so nothing new is hashed; and they are capped, so a label with unbounded values cannot grow the histogram without limit.

Field Summary

Fields inherited from class Instrument

COUNTER, GAUGE, HISTOGRAM, UP_DOWN_COUNTER

Method Summary

Modifier and Type	Method	Description
static double[]	defaultBounds()	A copy of OpenTelemetry's default explicit bucket boundaries.
String[]	getLabelKeys()	The label keys this histogram was created with.
List	points()	The current points, each a map with attributes (a map, possibly empty) and either value or, for a histogram, count, sum, min, max, bounds and buckets.
void	record(double value)	Records one value in the series without labels.
void	record(double value, Object first, Object second, Object third)	Records one value in the series for these label values, given in the order of the keys the histogram was created with.

Methods inherited from class Instrument

getDescription, getKind, getName, getUnit

Methods inherited from class Object

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

Method Details

defaultBounds

public static double[] defaultBounds()

A copy of OpenTelemetry's default explicit bucket boundaries.

getLabelKeys

public String[] getLabelKeys()

The label keys this histogram was created with.

record

public void record(double value)

Records one value in the series without labels.

record

public void record(double value,
 Object first,
 Object second,
 Object third)

Records one value in the series for these label values, given in the order of the keys the histogram was created with.

points

public List points()

Description copied from class: Instrument

The current points, each a map with attributes (a map, possibly empty) and either value or, for a histogram, count, sum, min, max, bounds and buckets.

Specified by:

points in class Instrument