Module iu.util

Package edu.iu

Class IuCachedValue<V>

java.lang.Object

edu.iu.IuCachedValue<V>

Type Parameters:

V - value type

public class IuCachedValue<V>
extends Object

Holds a single value by SoftReference with timed expiration.

A cached value could be cleared by the garbage collector in order to prevent OutOfMemoryError due to insufficient heap space.

Constructor Summary

Constructors

Constructor	Description
IuCachedValue(V value, Duration timeToLive, UnsafeRunnable onExpire)	Constructor.

Method Summary

Modifier and Type	Method	Description
void	clear()	Invalidates the cached value, invokes the onExpire thunk, and clears all related references and resource.
boolean	equals(Object obj)
V	get()	Gets the cached value.
boolean	has(Object o)	Determines if an object is equal to the referent.
int	hashCode()
boolean	isValid()	Determines whether or not the cached value is still valid.

Methods inherited from class java.lang.Object

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

Constructor Details

IuCachedValue

public IuCachedValue(V value,
 Duration timeToLive,
 UnsafeRunnable onExpire)

Constructor.

Parameters:

value - value

timeToLive - maximum length of time for the cached value to remain valid

onExpire - thunk to invoke when the reference expires; should execute quickly, i.e., to remove a map entry relative the provided key

Method Details

get

public V get()

Gets the cached value.

Returns:

cached value; may be null if the cached value is null, the reference was cleared by the garbage collector, or the expiration time is in the past.

isValid

public boolean isValid()

Determines whether or not the cached value is still valid.

Returns:

true if the reference is still valid; false if it has been cleared by the garbage collection or the expiration time is in the past.

has

public boolean has(Object o)

Determines if an object is equal to the referent.

Parameters:

o - object

Returns:

true if the reference is still valid and the referent is equal to the object.

clear

public void clear()

Invalidates the cached value, invokes the onExpire thunk, and clears all related references and resource.

This method has no effect if invoked on an invalid reference.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object