Package org.togglz.core.repository.cache

Class CachingStateRepository

java.lang.Object

org.togglz.core.repository.cache.CachingStateRepository

All Implemented Interfaces:

StateRepository

public class CachingStateRepository
extends Object
implements StateRepository

Simple implementation of StateRepository which adds caching capabilities to an existing repository. You should consider using this class if lookups in your StateRepository are expensive (like database queries).

Author:

Christian Kaltepoth

Constructor Summary

Constructors

Constructor	Description
CachingStateRepository(StateRepository delegate)	Creates a caching facade for the supplied StateRepository.
CachingStateRepository(StateRepository delegate, long ttl)	Creates a caching facade for the supplied StateRepository.
CachingStateRepository(StateRepository delegate, long ttl, TimeUnit ttlTimeUnit)	Creates a caching facade for the supplied StateRepository.

Method Summary

Modifier and Type	Method	Description
void	clear()	Clears the contents of the cache
FeatureState	getFeatureState(Feature feature)	Get the persisted state of a feature from the repository.
void	setFeatureState(FeatureState featureState)	Persist the supplied feature state.

Methods inherited from class java.lang.Object

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

Constructor Details

CachingStateRepository

public CachingStateRepository(StateRepository delegate)

Creates a caching facade for the supplied StateRepository. The cached state of a feature will only expire if setFeatureState(FeatureState) is invoked. You should therefore never use this constructor if the feature state is modified directly (for example by modifying the database table or the properties file).

Parameters:

delegate - The repository to delegate invocations to

CachingStateRepository

public CachingStateRepository(StateRepository delegate,
 long ttl)

Creates a caching facade for the supplied StateRepository. The cached state of a feature will expire after the supplied TTL or if setFeatureState(FeatureState) is invoked.

Parameters:

delegate - The repository to delegate invocations to

ttl - The time in milliseconds after which a cache entry will expire

Throws:

IllegalArgumentException - if the specified ttl is negative

CachingStateRepository

public CachingStateRepository(StateRepository delegate,
 long ttl,
 TimeUnit ttlTimeUnit)

Creates a caching facade for the supplied StateRepository. The cached state of a feature will expire after the supplied TTL rounded down to milliseconds or if setFeatureState(FeatureState) is invoked.

Parameters:

delegate - The repository to delegate invocations to

ttl - The time in a given ttlTimeUnit after which a cache entry will expire

ttlTimeUnit - The unit that ttl is expressed in

Method Details

getFeatureState

public FeatureState getFeatureState(Feature feature)

Description copied from interface: StateRepository

Get the persisted state of a feature from the repository. If the repository doesn't contain any information regarding this feature it must return null.

Specified by:

getFeatureState in interface StateRepository

Parameters:

feature - The feature to read the state for

Returns:

The persisted feature state or null

setFeatureState

public void setFeatureState(FeatureState featureState)

Description copied from interface: StateRepository

Persist the supplied feature state. The repository implementation must ensure that subsequent calls to StateRepository.getFeatureState(Feature) return the same state as persisted using this method.

Specified by:

setFeatureState in interface StateRepository

Parameters:

featureState - The feature state to persist

clear

public void clear()

Clears the contents of the cache