Package org.glassfish.jersey.server.internal.monitoring.core

Class AbstractSlidingWindowTimeReservoir<V>

java.lang.Object

org.glassfish.jersey.server.internal.monitoring.core.AbstractSlidingWindowTimeReservoir<V>

Type Parameters:

V - The type of values to store in this sliding window reservoir

All Implemented Interfaces:

TimeReservoir<V>

public abstract class AbstractSlidingWindowTimeReservoir<V>
extends Object
implements TimeReservoir<V>

An abstract TimeReservoir implementation backed by a sliding window that stores only the measurements made in the last N seconds (or other startTime unit) and allows an update with data that happened in past (which is what makes it different from Dropwizard's Metrics SlidingTimeWindowReservoir.

The snapshot this reservoir returns has limitations as mentioned in TimeReservoir.

This reservoir is capable to store up to 2^ReservoirConstants.COLLISION_BUFFER_POWER, that is 256, in a granularity of nanoseconds. In other words, up to 256 values that occurred at the same nanosecond can be stored in this reservoir. For particular nanosecond, if the collision buffer exceeds, newly added values are thrown away.

Author:

Stepan Vavra

See Also:

• Dropwizard's
   Metrics SlidingTimeWindowReservoir

Constructor Summary

Constructors

Constructor	Description
AbstractSlidingWindowTimeReservoir(long window, TimeUnit windowUnit, long startTime, TimeUnit startTimeUnit)	Creates a new SlidingWindowTimeReservoir with the start time and window of startTime.
AbstractSlidingWindowTimeReservoir(long window, TimeUnit windowUnit, long startTime, TimeUnit startTimeUnit, SlidingWindowTrimmer<V> trimmer)	Creates a new base sliding time window reservoir with the start time and a specified time window.

Method Summary

Modifier and Type	Method	Description
UniformTimeSnapshot	getSnapshot(long time, TimeUnit timeUnit)	Returns a snapshot of the reservoir's values at given time or newer.
long	interval(TimeUnit timeUnit)	The time interval this reservoir stores data of.
int	size(long time, TimeUnit timeUnit)	Returns the number of values recorded at given time or newer.
protected abstract UniformTimeSnapshot	snapshot(Collection<V> values, long timeInterval, TimeUnit timeIntervalUnit, long time, TimeUnit timeUnit)	Subclasses are required to instantiate UniformTimeSnapshot on their own.
void	update(V value, long time, TimeUnit timeUnit)	Adds a new recorded value to the reservoir bound to a given time.

Methods inherited from class java.lang.Object

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

Constructor Details

AbstractSlidingWindowTimeReservoir

public AbstractSlidingWindowTimeReservoir(long window,
 TimeUnit windowUnit,
 long startTime,
 TimeUnit startTimeUnit)

Creates a new SlidingWindowTimeReservoir with the start time and window of startTime.

Parameters:

window - The window of startTime

windowUnit - The unit of window

startTime - The start time from which this reservoir calculates measurements

startTimeUnit - The start time unit

AbstractSlidingWindowTimeReservoir

public AbstractSlidingWindowTimeReservoir(long window,
 TimeUnit windowUnit,
 long startTime,
 TimeUnit startTimeUnit,
 SlidingWindowTrimmer<V> trimmer)

Creates a new base sliding time window reservoir with the start time and a specified time window.

Parameters:

window - The window of startTime.

windowUnit - The unit of window.

startTime - The start time from which this reservoir calculates measurements.

startTimeUnit - The start time unit.

trimmer - The trimmer to use for trimming, if null, default trimmer is used.

Method Details

size

public int size(long time,
 TimeUnit timeUnit)

Description copied from interface: TimeReservoir

Returns the number of values recorded at given time or newer. It may not be supported to return a size in past due to performance optimizations.

Specified by:

size in interface TimeReservoir<V>

Parameters:

time - The time to get the size for

timeUnit - Time unit of the provided time

Returns:

the number of values recorded for given time or newer

update

public void update(V value,
 long time,
 TimeUnit timeUnit)

Description copied from interface: TimeReservoir

Adds a new recorded value to the reservoir bound to a given time.

Specified by:

update in interface TimeReservoir<V>

Parameters:

value - a new recorded value

time - The time the recorded value occurred at

timeUnit - Time unit of the provided time

interval

public long interval(TimeUnit timeUnit)

Description copied from interface: TimeReservoir

The time interval this reservoir stores data of.

Specified by:

interval in interface TimeReservoir<V>

Parameters:

timeUnit - The time unit in which to get the interval

Returns:

The time interval of this time reservoir

snapshot

protected abstract UniformTimeSnapshot snapshot(Collection<V> values,
 long timeInterval,
 TimeUnit timeIntervalUnit,
 long time,
 TimeUnit timeUnit)

Subclasses are required to instantiate UniformTimeSnapshot on their own.

Parameters:

values - The values to create the snapshot from

timeInterval - The time interval this snapshot conforms to

timeIntervalUnit - The interval unit of the time interval

time - The time of the request of the snapshot

timeUnit - The unit of the time of the snapshot request

Returns:

The snapshot

getSnapshot

public UniformTimeSnapshot getSnapshot(long time,
 TimeUnit timeUnit)

Description copied from interface: TimeReservoir

Returns a snapshot of the reservoir's values at given time or newer. It may not be supported to return a snapshot in past due to performance optimizations.

Specified by:

getSnapshot in interface TimeReservoir<V>

Parameters:

time - The time for which to get the snapshot

timeUnit - Time unit of the provided time

Returns:

a snapshot of the reservoir's values for given time or newer