org.apache.solr.util.stats
Class Timer

java.lang.Object
  org.apache.solr.util.stats.Timer

public class Timer
extends Object

A timer metric which aggregates timing durations and provides duration statistics, plus throughput statistics via Meter.

Constructor Summary

Timer()

Timer(TimeUnit durationUnit, TimeUnit rateUnit, Clock clock)
Creates a new Timer.

Method Summary

void	clear() Clears all recorded durations.
long	getCount()
TimeUnit	getDurationUnit() Returns the timer's duration scale unit.
String	getEventType()
double	getFifteenMinuteRate()
double	getFiveMinuteRate()
double	getMax() Returns the longest recorded duration.
double	getMean() Returns the arithmetic mean of all recorded durations.
double	getMeanRate()
double	getMin() Returns the shortest recorded duration.
double	getOneMinuteRate()
TimeUnit	getRateUnit()
Snapshot	getSnapshot()
double	getStdDev() Returns the standard deviation of all recorded durations.
double	getSum() Returns the sum of all recorded durations.
TimerContext	time() Returns a timing TimerContext, which measures an elapsed time in nanoseconds.
<T> T	time(Callable<T> event) Times and records the duration of event.
void	update(long duration, TimeUnit unit) Adds a recorded duration.

Methods inherited from class java.lang.Object

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

Constructor Detail

Timer

public Timer()

Timer

public Timer(TimeUnit durationUnit,
             TimeUnit rateUnit,
             Clock clock)

Creates a new Timer.

Parameters:

durationUnit - the scale unit for this timer's duration metrics

rateUnit - the scale unit for this timer's rate metrics

clock - the clock used to calculate duration

Method Detail

getDurationUnit

public TimeUnit getDurationUnit()

Returns the timer's duration scale unit.

Returns:

the timer's duration scale unit

getRateUnit

public TimeUnit getRateUnit()

clear

public void clear()

Clears all recorded durations.

update

public void update(long duration,
                   TimeUnit unit)

Adds a recorded duration.

Parameters:

duration - the length of the duration

unit - the scale unit of duration

time

public <T> T time(Callable<T> event)
       throws Exception

Times and records the duration of event.

Type Parameters:

T - the type of the value returned by event

Parameters:

event - a Callable whose Callable.call() method implements a process whose duration should be timed

Returns:

the value returned by event

Throws:

Exception - if event throws an Exception

time

public TimerContext time()

Returns a timing TimerContext, which measures an elapsed time in nanoseconds.

Returns:

a new TimerContext

getCount

public long getCount()

getFifteenMinuteRate

public double getFifteenMinuteRate()

getFiveMinuteRate

public double getFiveMinuteRate()

getMeanRate

public double getMeanRate()

getOneMinuteRate

public double getOneMinuteRate()

getMax

public double getMax()

Returns the longest recorded duration.

Returns:

the longest recorded duration

getMin

public double getMin()

Returns the shortest recorded duration.

Returns:

the shortest recorded duration

getMean

public double getMean()

Returns the arithmetic mean of all recorded durations.

Returns:

the arithmetic mean of all recorded durations

getStdDev

public double getStdDev()

Returns the standard deviation of all recorded durations.

Returns:

the standard deviation of all recorded durations

getSum

public double getSum()

Returns the sum of all recorded durations.

Returns:

the sum of all recorded durations

getSnapshot

public Snapshot getSnapshot()

getEventType

public String getEventType()