com.berryworks.jquantify

Class EventCounter

java.lang.Object

com.berryworks.jquantify.Metric

com.berryworks.jquantify.EventCounter

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

SessionCounter

public class EventCounter
extends Metric

This class is used to count and observe the frequency of events.

An EventCounter treats events as instantaneous, happening at a specific point in time and with no observable duration. For observing events that have both frequency and duration, consider a SessionCounter.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected EventCounterInterval	mCurrentInterval
protected long	mNow
protected EventCounterInterval	mPeakEvents
protected EventCounterInterval	mPriorInterval

Fields inherited from class com.berryworks.jquantify.Metric

intervalSeconds, startTime, totalIntervals

Constructor Summary

Constructors

Constructor and Description
EventCounter()
EventCounter(String inLabel) Constructs a new EventCounter with an interval duration of 1 second.
EventCounter(String inLabel, int inIntervalSeconds) Constructs an EventCounter with a specific interval duration.

Method Summary

Methods

Modifier and Type	Method and Description
void	add(int inCount) Adds a number events.
protected void	createIntervals()
long	getCount() Gets the total count of events.
long	getCumulativeEvents() Equivalent to getCount(), gets the total number of events added to this EventCounter.
float	getCumulativeFreq() Gets the overall event frequency for this EventCounter
float	getCurrentFreq() Gets the current event frequency for this EventCounter.
Interval	getCurrentInterval() Gets the current Interval, the one to which current events are added.
static EventCounter	getEventCounter(String inLabel) Get an instance of an EventCounter with a particular label from the MetricRepository, creating one if necessary.
long	getPeakEvents() Gets the number of events that occurred during the interval in which the most events occurred.
EventCounterInterval	getPeakEventsInterval() Gets the interval in which the greatest number of events were added.
void	normalize() Normalizes this EventCounter if necessary.
protected void	normalizeCurrent_ScenarioA()
protected void	normalizeCurrent_ScenarioB()
protected void	normalizePrior_ScenarioA()
protected void	normalizePrior_ScenarioB(long nEmptyIntervals)
void	reset() Reset this EventCounter to its "zero" condition so that it can be reused, avoiding the overhead of constructing a new instance.

Methods inherited from class com.berryworks.jquantify.Metric

add, getAge, getAgeMillis, getIntervalSeconds, getLabel, getTotalIntervals, setLabel, uptime

Methods inherited from class java.lang.Object

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

Field Detail

mCurrentInterval

protected EventCounterInterval mCurrentInterval

mPriorInterval

protected EventCounterInterval mPriorInterval

mPeakEvents

protected EventCounterInterval mPeakEvents

mNow

protected long mNow

Constructor Detail

EventCounter

public EventCounter()

EventCounter

public EventCounter(String inLabel,
            int inIntervalSeconds)

Constructs an EventCounter with a specific interval duration.

Parameters:

inLabel - descriptive String used in reporting

inIntervalSeconds - int duration of each interval in seconds

EventCounter

public EventCounter(String inLabel)

Constructs a new EventCounter with an interval duration of 1 second.

Parameters:

inLabel - descriptive String used in reporting

Method Detail

getEventCounter

public static EventCounter getEventCounter(String inLabel)

Get an instance of an EventCounter with a particular label from the MetricRepository, creating one if necessary.

Parameters:

inLabel - Description of the Parameter

Returns:

The eventCounter value

getCurrentInterval

public Interval getCurrentInterval()

Gets the current Interval, the one to which current events are added.

Returns:

Interval - the current interval

getPeakEventsInterval

public EventCounterInterval getPeakEventsInterval()

Gets the interval in which the greatest number of events were added.

Returns:

Interval - having the greatest getEvents()

getPeakEvents

public long getPeakEvents()

Gets the number of events that occurred during the interval in which the most events occurred. A convenience method equivalent to getPeakEventsInterval().getEvents()

Returns:

The peakEvents value

getCount

public long getCount()

Description copied from class: Metric

Gets the total count of events.

Specified by:

getCount in class Metric

Returns:

count

getCumulativeEvents

public long getCumulativeEvents()

Equivalent to getCount(), gets the total number of events added to this EventCounter.

Returns:

total number of events

getCumulativeFreq

public float getCumulativeFreq()

Gets the overall event frequency for this EventCounter

Returns:

float - events per second

getCurrentFreq

public float getCurrentFreq()

Gets the current event frequency for this EventCounter. The calculation includes the current incomplete interval. In order to reduce excessive fluctuations when the current interval has just begun, the immediately preceding interval, if one exists, is also included in the calculation.

Returns:

float - events per second

add

public void add(int inCount)

Adds a number events.

All events are considered to have happened now simultaneously.

Specified by:

add in class Metric

Parameters:

inCount - number of events counted by this call

normalize

public void normalize()

Normalizes this EventCounter if necessary. An EventCounter is considered to be normalized if the current time falls within the time span implied by the currentInterval. Once enough time has elapsed for the currentInterval to be outdated, then normalize() closes it and opens up a new currentInterval.

normalizeCurrent_ScenarioA

protected void normalizeCurrent_ScenarioA()

normalizePrior_ScenarioA

protected void normalizePrior_ScenarioA()

normalizeCurrent_ScenarioB

protected void normalizeCurrent_ScenarioB()

normalizePrior_ScenarioB

protected void normalizePrior_ScenarioB(long nEmptyIntervals)

reset

public void reset()

Reset this EventCounter to its "zero" condition so that it can be reused, avoiding the overhead of constructing a new instance.

Overrides:

reset in class Metric

createIntervals

protected void createIntervals()