org.apache.calcite.avatica.metrics.noop

Class NoopMetricsSystem

java.lang.Object

org.apache.calcite.avatica.metrics.noop.NoopMetricsSystem

All Implemented Interfaces:

MetricsSystem

public class NoopMetricsSystem
extends Object
implements MetricsSystem

MetricsSystem implementation which does nothing. Returns Metric implementations which also does nothing (avoiding null instances).

Field Summary

Fields

Modifier and Type	Field and Description
private static Counter	COUNTER
private static Histogram	HISTOGRAM
private static Meter	METER
private static NoopMetricsSystem	NOOP_METRICS
private static Timer	TIMER

Constructor Summary

Constructors

Modifier	Constructor and Description
private	NoopMetricsSystem()

Method Summary

Methods

Modifier and Type	Method and Description
Counter	getCounter(String name) Get or construct a Counter used to track a mutable number.
Histogram	getHistogram(String name) Get or construct a Histogram used to measure a distribution of values.
static NoopMetricsSystem	getInstance()
Meter	getMeter(String name) Get or construct a Meter used to measure durations and report distributions (a combination of a Timer and a Histogram.
Timer	getTimer(String name) Get or construct a Timer used to measure durations and report rates.
<T> void	register(String name, Gauge<T> gauge) Register a Gauge.

Methods inherited from class java.lang.Object

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

Field Detail

NOOP_METRICS

private static final NoopMetricsSystem NOOP_METRICS

TIMER

private static final Timer TIMER

HISTOGRAM

private static final Histogram HISTOGRAM

METER

private static final Meter METER

COUNTER

private static final Counter COUNTER

Constructor Detail

NoopMetricsSystem

private NoopMetricsSystem()

Method Detail

getInstance

public static NoopMetricsSystem getInstance()

Returns:

A NoopMetricsSystem instance.

getTimer

public Timer getTimer(String name)

Description copied from interface: MetricsSystem

Get or construct a Timer used to measure durations and report rates.

Specified by:

getTimer in interface MetricsSystem

Parameters:

name - The name of the Timer.

Returns:

An instance of Timer.

getHistogram

public Histogram getHistogram(String name)

Description copied from interface: MetricsSystem

Get or construct a Histogram used to measure a distribution of values.

Specified by:

getHistogram in interface MetricsSystem

Parameters:

name - The name of the Histogram.

Returns:

An instance of Histogram.

getMeter

public Meter getMeter(String name)

Description copied from interface: MetricsSystem

Get or construct a Meter used to measure durations and report distributions (a combination of a Timer and a Histogram.

Specified by:

getMeter in interface MetricsSystem

Parameters:

name - The name of the Meter.

Returns:

An instance of Meter.

getCounter

public Counter getCounter(String name)

Description copied from interface: MetricsSystem

Get or construct a Counter used to track a mutable number.

Specified by:

getCounter in interface MetricsSystem

Parameters:

name - The name of the Counter

Returns:

An instance of Counter.

register

public <T> void register(String name,
                Gauge<T> gauge)

Description copied from interface: MetricsSystem

Register a Gauge. The Gauge will be invoked at a period defined by the implementation of MetricsSystem.

Specified by:

register in interface MetricsSystem

Parameters:

name - The name of the Gauge.

gauge - A callback to compute the current value.