com.yammer.metrics.core

Class DeltaCounter

java.lang.Object

com.yammer.metrics.core.Counter

com.yammer.metrics.core.DeltaCounter

All Implemented Interfaces:

com.yammer.metrics.core.Metric

public class DeltaCounter
extends com.yammer.metrics.core.Counter

A counter for Wavefront delta metrics. Differs from a counter in that it is reset every time the value is reported. (This is similar to how WavefrontHistogram is implemented)

Author:

Suranjan Pramanik (suranjan@wavefront.com)

Method Summary

Modifier and Type	Method and Description
static DeltaCounter	get(com.yammer.metrics.core.MetricName metricName) A static factory method to create an instance of DeltaCounter.
static DeltaCounter	get(com.yammer.metrics.core.MetricsRegistry registry, com.yammer.metrics.core.MetricName metricName) A static factory method to create an instance of Delta Counter.
static com.yammer.metrics.core.MetricName	getDeltaCounterMetricName(com.yammer.metrics.core.MetricName metricName) This method transforms the MetricName into a new MetricName that represents a DeltaCounter.
static String	getDeltaCounterName(String name) A helper function to transform a counter name to a DeltaCounter name.
static String	getNameWithoutDeltaPrefix(String name) A helper function to transform the name from a DeltaCounter name to a new name by removing the "∆" prefix.
static boolean	isDelta(String name) This method checks whether the name is a valid DeltaCounter name.
static long	processDeltaCounter(DeltaCounter counter) This method returns the current count of the DeltaCounter and resets the counter.

Methods inherited from class com.yammer.metrics.core.Counter

clear, count, dec, dec, inc, inc, processWith

Methods inherited from class java.lang.Object

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

Method Detail

get

public static DeltaCounter get(com.yammer.metrics.core.MetricsRegistry registry,
                               com.yammer.metrics.core.MetricName metricName)

A static factory method to create an instance of Delta Counter.

Parameters:

registry - The MetricRegistry to use

metricName - The MetricName to use

Returns:

An instance of DeltaCounter

get

public static DeltaCounter get(com.yammer.metrics.core.MetricName metricName)

A static factory method to create an instance of DeltaCounter. It uses the default MetricsRegistry.

Parameters:

metricName - The MetricName to use

Returns:

An instance of DeltaCounter

processDeltaCounter

public static long processDeltaCounter(DeltaCounter counter)

This method returns the current count of the DeltaCounter and resets the counter.

Parameters:

counter - The DeltaCounter whose value is requested

Returns:

The current count of the DeltaCounter

getDeltaCounterMetricName

public static com.yammer.metrics.core.MetricName getDeltaCounterMetricName(com.yammer.metrics.core.MetricName metricName)

This method transforms the MetricName into a new MetricName that represents a DeltaCounter. The transformation includes prepending a "∆" character to the name.

Parameters:

metricName - The MetricName which needs to be transformed

Returns:

The new MetricName representing a DeltaCounter

getDeltaCounterName

public static String getDeltaCounterName(String name)

A helper function to transform a counter name to a DeltaCounter name. The transformation includes prepending a "∆" character to the name.

Parameters:

name - The name which needs to be transformed

Returns:

The new name representing a DeltaCounter

isDelta

public static boolean isDelta(String name)

This method checks whether the name is a valid DeltaCounter name.

Parameters:

name - The name which needs to be checked

Returns:

True if the name is a valid DeltaCounter name, otherwise returns false

getNameWithoutDeltaPrefix

public static String getNameWithoutDeltaPrefix(String name)

A helper function to transform the name from a DeltaCounter name to a new name by removing the "∆" prefix. If the name is not a DeltaCounter name then the input name is returned.

Parameters:

name - The name which needs to be transformed

Returns:

The transformed name