Package org.flasby.util

Class ShinyCache<Key,Value>

java.lang.Object

org.flasby.util.ShinyCache<Key,Value>

All Implemented Interfaces:

BlockingCache<Key,Value>, Cache<Key,Value>

public abstract class ShinyCache<Key,Value>
extends Object
implements BlockingCache<Key,Value>

is a cache which handles entry expiry and will ensure that multiple simultaneous requests using the same key will only make a single request to get the missing value. Simultaneous requests will be queued until the value is returned. Cached entries may have a NULL value.

Author:

Steve Flasby 21 Sep 2012

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	ShinyCache.EvictionPolicy

Constructor Summary

Constructors

Constructor	Description
ShinyCache()	simple, ever growing, cache
ShinyCache(int capacity, ShinyCache.EvictionPolicy evictionPolicy)
ShinyCache(org.flasby.util.ShinyCache.ExpiryPolicy expiryPolicy)	cache which expires entries after a fixed lifetime.
ShinyCache(org.flasby.util.ShinyCache.ExpiryPolicy expiryPolicy, int capacity, ShinyCache.EvictionPolicy evictionPolicy)

Method Summary

Modifier and Type	Method	Description
static org.flasby.util.ShinyCache.ExpiryPolicy	expireAfterMillis(long periodInMillis)
Value	get(Key key)	gets the key form the cache or returns NULL if the Thread was interrupted.
Value	getAndWait(Key key)	attempts to get a value from the Cache.
Value	getAndWait(Key key, long maxWaitMillis)	attempt to get a value from the cache.
Iterator<Value>	iterator()
static org.flasby.util.ShinyCache.ExpiryPolicy	never()
int	size()

Methods inherited from class java.lang.Object

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

Constructor Details

ShinyCache

public ShinyCache()

simple, ever growing, cache

ShinyCache

public ShinyCache(org.flasby.util.ShinyCache.ExpiryPolicy expiryPolicy)

cache which expires entries after a fixed lifetime.

Parameters:

expiryPolicy -

ShinyCache

public ShinyCache(int capacity,
 ShinyCache.EvictionPolicy evictionPolicy)

ShinyCache

public ShinyCache(org.flasby.util.ShinyCache.ExpiryPolicy expiryPolicy,
 int capacity,
 ShinyCache.EvictionPolicy evictionPolicy)

Method Details

never

public static org.flasby.util.ShinyCache.ExpiryPolicy never()

expireAfterMillis

public static org.flasby.util.ShinyCache.ExpiryPolicy expireAfterMillis(long periodInMillis)

get

public Value get(Key key)

gets the key form the cache or returns NULL if the Thread was interrupted.

Specified by:

get in interface Cache<Key,Value>

getAndWait

public Value getAndWait(Key key)
                 throws InterruptedException

Description copied from interface: BlockingCache

attempts to get a value from the Cache. If a previous request to populate the cache with the value for this key is in progress, then the current thread should block until the cache is populated.

Specified by:

getAndWait in interface BlockingCache<Key,Value>

Parameters:

key -

Returns:

Throws:

InterruptedException

getAndWait

public Value getAndWait(Key key,
 long maxWaitMillis)
                 throws InterruptedException

Description copied from interface: BlockingCache

attempt to get a value from the cache. If a previous request to populate the cache with the value for this key is in progress, then the current thread will block for at most maxWaitMillis until the cache is populated. Should no value become available within this maxWait time then the cache will return null.

Specified by:

getAndWait in interface BlockingCache<Key,Value>

Parameters:

key -

maxWaitMillis -

Returns:

Throws:

InterruptedException

size

public int size()

Specified by:

size in interface Cache<Key,Value>

iterator

public Iterator<Value> iterator()

Specified by:

iterator in interface Cache<Key,Value>