com.netflix.spectator.api

Class AbstractMeter<T>

java.lang.Object

com.netflix.spectator.api.AbstractMeter<T>

All Implemented Interfaces:

Meter

public abstract class AbstractMeter<T>
extends java.lang.Object
implements Meter

Helper base class for meters that maintains a weak reference to the object being measured. Meters that are based on polling rather than activity need some other way to define the lifespan and in this case that is if the reference still exists. Basing this off a weak reference means there doesn't need to be an explicit de-registration and registering to collect insight will not prevent garbage collection of the underlying object.

Field Summary

Fields

Modifier and Type	Field and Description
protected Clock	clock Clock to use for getting measurement timestamps.
protected Id	id Identifier for the meter.
protected java.lang.ref.WeakReference<T>	ref Reference to the underlying object used to compute the measurements.

Constructor Summary

Constructors

Constructor and Description
AbstractMeter(Clock clock, Id id, T obj) Create a new instance.

Method Summary

Modifier and Type	Method and Description
boolean	hasExpired() Indicates whether the meter is expired.
Id	id() Identifier used to lookup this meter in the registry.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.netflix.spectator.api.Meter

measure

Field Detail

clock

protected final Clock clock

Clock to use for getting measurement timestamps.

id

protected final Id id

Identifier for the meter.

ref

protected final java.lang.ref.WeakReference<T> ref

Reference to the underlying object used to compute the measurements.

Constructor Detail

AbstractMeter

public AbstractMeter(Clock clock,
                     Id id,
                     T obj)

Create a new instance.

Parameters:

clock - Clock to use for getting measurement timestamps. Typically should be the clock used by the registry (see Registry.clock()).

id - Identifier for the meter.

obj - Reference to the underlying object used to compute the measurements.

Method Detail

id

public Id id()

Description copied from interface: Meter

Identifier used to lookup this meter in the registry.

Specified by:

id in interface Meter

hasExpired

public boolean hasExpired()

Description copied from interface: Meter

Indicates whether the meter is expired. For example, a counter might expire if there is no activity within a given time frame.

Specified by:

hasExpired in interface Meter