Package io.opentelemetry.api.metrics

Class DefaultMeter

java.lang.Object

io.opentelemetry.api.metrics.DefaultMeter

All Implemented Interfaces:

Meter

@ThreadSafe
class DefaultMeter
extends java.lang.Object
implements Meter

No-op implementation of Meter.

This implementation should induce as close to zero overhead as possible.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	DefaultMeter.NoopDoubleCounter
private static class	DefaultMeter.NoopDoubleCounterBuilder
private static class	DefaultMeter.NoopDoubleGauge
private static class	DefaultMeter.NoopDoubleGaugeBuilder
private static class	DefaultMeter.NoopDoubleHistogram
private static class	DefaultMeter.NoopDoubleHistogramBuilder
private static class	DefaultMeter.NoopDoubleUpDownCounter
private static class	DefaultMeter.NoopDoubleUpDownCounterBuilder
private static class	DefaultMeter.NoopLongCounter
private static class	DefaultMeter.NoopLongCounterBuilder
private static class	DefaultMeter.NoopLongGauge
private static class	DefaultMeter.NoopLongGaugeBuilder
private static class	DefaultMeter.NoopLongHistogram
private static class	DefaultMeter.NoopLongHistogramBuilder
private static class	DefaultMeter.NoopLongUpDownCounter
private static class	DefaultMeter.NoopLongUpDownCounterBuilder
private static class	DefaultMeter.NoopObservableDoubleMeasurement
private static class	DefaultMeter.NoopObservableLongMeasurement

Field Summary

Fields

Modifier and Type	Field	Description
private static Meter	INSTANCE
private static BatchCallback	NOOP_BATCH_CALLBACK
private static DoubleGaugeBuilder	NOOP_DOUBLE_GAUGE_BUILDER
private static DoubleHistogramBuilder	NOOP_DOUBLE_HISTOGRAM_BUILDER
private static LongCounterBuilder	NOOP_LONG_COUNTER_BUILDER
private static LongUpDownCounterBuilder	NOOP_LONG_UP_DOWN_COUNTER_BUILDER
private static ObservableDoubleMeasurement	NOOP_OBSERVABLE_DOUBLE_MEASUREMENT
private static ObservableLongMeasurement	NOOP_OBSERVABLE_LONG_MEASUREMENT

Constructor Summary

Constructors

Modifier	Constructor	Description
private	DefaultMeter()

Method Summary

Modifier and Type	Method	Description
BatchCallback	batchCallback(java.lang.Runnable callback, ObservableMeasurement observableMeasurement, ObservableMeasurement... additionalMeasurements)	Constructs a batch callback.
LongCounterBuilder	counterBuilder(java.lang.String name)	Constructs a Counter instrument.
DoubleGaugeBuilder	gaugeBuilder(java.lang.String name)	Constructs an Asynchronous Gauge instrument.
(package private) static Meter	getInstance()
DoubleHistogramBuilder	histogramBuilder(java.lang.String name)	Constructs a Histogram instrument.
LongUpDownCounterBuilder	upDownCounterBuilder(java.lang.String name)	Constructs an UpDownCounter instrument.

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

private static final Meter INSTANCE

NOOP_LONG_COUNTER_BUILDER

private static final LongCounterBuilder NOOP_LONG_COUNTER_BUILDER

NOOP_LONG_UP_DOWN_COUNTER_BUILDER

private static final LongUpDownCounterBuilder NOOP_LONG_UP_DOWN_COUNTER_BUILDER

NOOP_DOUBLE_HISTOGRAM_BUILDER

private static final DoubleHistogramBuilder NOOP_DOUBLE_HISTOGRAM_BUILDER

NOOP_DOUBLE_GAUGE_BUILDER

private static final DoubleGaugeBuilder NOOP_DOUBLE_GAUGE_BUILDER

NOOP_BATCH_CALLBACK

private static final BatchCallback NOOP_BATCH_CALLBACK

NOOP_OBSERVABLE_DOUBLE_MEASUREMENT

private static final ObservableDoubleMeasurement NOOP_OBSERVABLE_DOUBLE_MEASUREMENT

NOOP_OBSERVABLE_LONG_MEASUREMENT

private static final ObservableLongMeasurement NOOP_OBSERVABLE_LONG_MEASUREMENT

Constructor Detail

DefaultMeter

private DefaultMeter()

Method Detail

getInstance

static Meter getInstance()

counterBuilder

public LongCounterBuilder counterBuilder(java.lang.String name)

Description copied from interface: Meter

Constructs a Counter instrument.

This is used to build both synchronous instruments and asynchronous instruments (i.e. callbacks).

Specified by:

counterBuilder in interface Meter

Parameters:

name - the name of the Counter. Instrument names must consist of 255 or fewer characters including alphanumeric, _, ., -, /, and start with a letter.

Returns:

a builder for configuring a Counter instrument. Defaults to recording long values, but may be changed.

See Also:

Instrument Naming Rule

upDownCounterBuilder

public LongUpDownCounterBuilder upDownCounterBuilder(java.lang.String name)

Description copied from interface: Meter

Constructs an UpDownCounter instrument.

This is used to build both synchronous instruments and asynchronous instruments (i.e. callbacks).

Specified by:

upDownCounterBuilder in interface Meter

Parameters:

name - the name of the UpDownCounter. Instrument names must consist of 255 or fewer characters including alphanumeric, _, ., -, /, and start with a letter.

Returns:

a builder for configuring an UpDownCounter instrument. Defaults to recording long values, but may be changed.

See Also:

Instrument Naming Rule

histogramBuilder

public DoubleHistogramBuilder histogramBuilder(java.lang.String name)

Description copied from interface: Meter

Constructs a Histogram instrument.

Specified by:

histogramBuilder in interface Meter

Parameters:

name - the name of the Histogram. Instrument names must consist of 255 or fewer characters including alphanumeric, _, ., -, /, and start with a letter.

Returns:

a builder for configuring a Histogram synchronous instrument. Defaults to recording double values, but may be changed.

See Also:

Instrument Naming Rule

gaugeBuilder

public DoubleGaugeBuilder gaugeBuilder(java.lang.String name)

Description copied from interface: Meter

Constructs an Asynchronous Gauge instrument.

Specified by:

gaugeBuilder in interface Meter

Parameters:

name - the name of the Gauge. Instrument names must consist of 255 or fewer characters including alphanumeric, _, ., -, /, and start with a letter.

Returns:

a builder used for configuring a Gauge instrument. Defaults to recording double values, but may be changed.

See Also:

Instrument Naming Rule

batchCallback

public BatchCallback batchCallback(java.lang.Runnable callback,
                                   ObservableMeasurement observableMeasurement,
                                   ObservableMeasurement... additionalMeasurements)

Description copied from interface: Meter

Constructs a batch callback.

Batch callbacks allow a single callback to observe measurements for multiple asynchronous instruments.

The callback will be called when the instruments are being observed.

Callbacks are expected to abide by the following restrictions:

• Run in a finite amount of time.
• Safe to call repeatedly, across multiple threads.
• Only observe values to registered instruments (i.e. observableMeasurement and additionalMeasurements

Specified by:

batchCallback in interface Meter

Parameters:

callback - a callback used to observe values on-demand.

observableMeasurement - Instruments for which the callback may observe values.

additionalMeasurements - Instruments for which the callback may observe values.