org.apache.tez.common

Class CachedEntity<T>

java.lang.Object

org.apache.tez.common.CachedEntity<T>

Type Parameters:

T - the data object type.

public class CachedEntity<T>
extends Object

A thread safe implementation used as a container for cacheable entries with Expiration times. It supports custom Clock to control the elapsed time calculation.

Constructor Summary

Constructors

Constructor and Description
CachedEntity(TimeUnit expiryTimeUnit, long expiryLength)
CachedEntity(TimeUnit expiryTimeUnit, long expiryLength, org.apache.hadoop.yarn.util.Clock clock)

Method Summary

Modifier and Type	Method and Description
void	enforceExpiration() Enforces the expiration of the cached entry.
T	getValue() If the entry has expired, it reset the cache reference through clearExpiredEntry().
boolean	isExpired()
void	setValue(T newEntry) Safely sets the cached data.

Methods inherited from class java.lang.Object

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

Constructor Detail

CachedEntity

public CachedEntity(TimeUnit expiryTimeUnit,
                    long expiryLength,
                    org.apache.hadoop.yarn.util.Clock clock)

CachedEntity

public CachedEntity(TimeUnit expiryTimeUnit,
                    long expiryLength)

Method Detail

isExpired

public boolean isExpired()

Returns:

true if expiration timestamp is 0, or the elapsed time since last update is greater than expiryDurationMS

getValue

public T getValue()

If the entry has expired, it reset the cache reference through clearExpiredEntry().

Returns:

cached data if the timestamp is valid. Null, if the timestamp has expired.

setValue

public void setValue(T newEntry)

Safely sets the cached data.

Parameters:

newEntry -

enforceExpiration

public void enforceExpiration()

Enforces the expiration of the cached entry.