Class ReservoirCell

java.lang.Object

io.opentelemetry.sdk.metrics.internal.exemplar.ReservoirCell

class ReservoirCell
extends Object

A Reservoir cell pre-allocated memories for Exemplar data.

We only allocate new objects during collection. This class should NOT cause allocations during sampling or within the synchronous metric hot-path.

Allocations are acceptable in the getAndResetDouble(Attributes) and getAndResetLong(Attributes) collection methods.

Field Summary

Fields

Modifier and Type	Field	Description
private Attributes	attributes
private final Clock	clock
private double	doubleValue
private long	longValue
private long	recordTime
private SpanContext	spanContext

Constructor Summary

Constructors

Constructor	Description
ReservoirCell(Clock clock)

Method Summary

Modifier and Type	Method	Description
private static Attributes	filtered(Attributes original, Attributes metricPoint)	Returns filtered attributes for exemplars.
(package private) DoubleExemplarData	getAndResetDouble(Attributes pointAttributes)	Retrieve the cell's ExemplarData.
(package private) LongExemplarData	getAndResetLong(Attributes pointAttributes)	Retrieve the cell's ExemplarData.
private void	offerMeasurement(Attributes attributes, Context context)
(package private) void	recordDoubleMeasurement(double value, Attributes attributes, Context context)	Record the long measurement to the cell.
(package private) void	recordLongMeasurement(long value, Attributes attributes, Context context)	Record the long measurement to the cell.
(package private) void	reset()

Methods inherited from class Object

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

Field Details

clock

private final Clock clock

attributes

@Nullable
private Attributes attributes

spanContext

private SpanContext spanContext

recordTime

private long recordTime

longValue

private long longValue

doubleValue

private double doubleValue

Constructor Details

ReservoirCell

ReservoirCell(Clock clock)

Method Details

recordLongMeasurement

void recordLongMeasurement(long value,
 Attributes attributes,
 Context context)

Record the long measurement to the cell.

Must be used in tandem with getAndResetLong(Attributes). recordDoubleMeasurement(double, Attributes, Context) and getAndResetDouble(Attributes) must not be used when a cell is recording longs.

recordDoubleMeasurement

void recordDoubleMeasurement(double value,
 Attributes attributes,
 Context context)

Record the long measurement to the cell.

Must be used in tandem with getAndResetDouble(Attributes). recordLongMeasurement(long, Attributes, Context) and getAndResetLong(Attributes) must not be used when a cell is recording longs.

offerMeasurement

private void offerMeasurement(Attributes attributes,
 Context context)

getAndResetLong

@Nullable
LongExemplarData getAndResetLong(Attributes pointAttributes)

Retrieve the cell's ExemplarData.

Must be used in tandem with recordLongMeasurement(long, Attributes, Context).

getAndResetDouble

@Nullable
DoubleExemplarData getAndResetDouble(Attributes pointAttributes)

Retrieve the cell's ExemplarData.

Must be used in tandem with recordDoubleMeasurement(double, Attributes, Context).

reset

void reset()

filtered

private static Attributes filtered(Attributes original,
 Attributes metricPoint)

Returns filtered attributes for exemplars.