Package com.codahale.metrics

Class Timer

java.lang.Object

com.codahale.metrics.Timer

All Implemented Interfaces:

Counting, Metered, Metric, Sampling

public class Timer
extends Object
implements Metered, Sampling

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

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Timer.Context	A timing context.

Field Summary

Fields

Modifier and Type	Field	Description
private final Clock	clock
private final Histogram	histogram
private final Meter	meter

Constructor Summary

Constructors

Constructor	Description
Timer()	Creates a new Timer using an ExponentiallyDecayingReservoir and the default Clock.
Timer(Reservoir reservoir)	Creates a new Timer that uses the given Reservoir.
Timer(Reservoir reservoir, Clock clock)	Creates a new Timer that uses the given Reservoir and Clock.

Method Summary

Modifier and Type	Method	Description
long	getCount()	Returns the number of events which have been marked.
double	getFifteenMinuteRate()	Returns the fifteen-minute exponentially-weighted moving average rate at which events have occurred since the meter was created.
double	getFiveMinuteRate()	Returns the five-minute exponentially-weighted moving average rate at which events have occurred since the meter was created.
double	getMeanRate()	Returns the mean rate at which events have occurred since the meter was created.
double	getOneMinuteRate()	Returns the one-minute exponentially-weighted moving average rate at which events have occurred since the meter was created.
Snapshot	getSnapshot()	Returns a snapshot of the values.
Timer.Context	time()	Returns a new Timer.Context.
<T> T	time(Callable<T> event)	Times and records the duration of event.
private void	update(long duration)
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

Field Details

meter

private final Meter meter

histogram

private final Histogram histogram

clock

private final Clock clock

Constructor Details

Timer

public Timer()

Creates a new Timer using an ExponentiallyDecayingReservoir and the default Clock.

Timer

public Timer(Reservoir reservoir)

Creates a new Timer that uses the given Reservoir.

Parameters:

reservoir - the Reservoir implementation the timer should use

Timer

public Timer(Reservoir reservoir,
 Clock clock)

Creates a new Timer that uses the given Reservoir and Clock.

Parameters:

reservoir - the Reservoir implementation the timer should use

clock - the Clock implementation the timer should use

Method Details

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 Timer.Context time()

Returns a new Timer.Context.

Returns:

a new Timer.Context

See Also:

• Timer.Context

getCount

public long getCount()

Description copied from interface: Metered

Returns the number of events which have been marked.

Specified by:

getCount in interface Counting

Specified by:

getCount in interface Metered

Returns:

the number of events which have been marked

getFifteenMinuteRate

public double getFifteenMinuteRate()

Description copied from interface: Metered

Returns the fifteen-minute exponentially-weighted moving average rate at which events have occurred since the meter was created.

This rate has the same exponential decay factor as the fifteen-minute load average in the top Unix command.

Specified by:

getFifteenMinuteRate in interface Metered

Returns:

the fifteen-minute exponentially-weighted moving average rate at which events have occurred since the meter was created

getFiveMinuteRate

public double getFiveMinuteRate()

Description copied from interface: Metered

Returns the five-minute exponentially-weighted moving average rate at which events have occurred since the meter was created.

This rate has the same exponential decay factor as the five-minute load average in the top Unix command.

Specified by:

getFiveMinuteRate in interface Metered

Returns:

the five-minute exponentially-weighted moving average rate at which events have occurred since the meter was created

getMeanRate

public double getMeanRate()

Description copied from interface: Metered

Returns the mean rate at which events have occurred since the meter was created.

Specified by:

getMeanRate in interface Metered

Returns:

the mean rate at which events have occurred since the meter was created

getOneMinuteRate

public double getOneMinuteRate()

Description copied from interface: Metered

Returns the one-minute exponentially-weighted moving average rate at which events have occurred since the meter was created.

This rate has the same exponential decay factor as the one-minute load average in the top Unix command.

Specified by:

getOneMinuteRate in interface Metered

Returns:

the one-minute exponentially-weighted moving average rate at which events have occurred since the meter was created

getSnapshot

public Snapshot getSnapshot()

Description copied from interface: Sampling

Returns a snapshot of the values.

Specified by:

getSnapshot in interface Sampling

Returns:

a snapshot of the values

update

private void update(long duration)