net.itrixlabs.cache.core

Interface ApplicationCache<K,V>

All Superinterfaces:

org.springframework.beans.factory.DisposableBean, org.springframework.beans.factory.InitializingBean

All Known Implementing Classes:

AbstractFileSystemCache, SerializableAuthCache, SerializableUserCache

public interface ApplicationCache<K,V>
extends org.springframework.beans.factory.InitializingBean, org.springframework.beans.factory.DisposableBean

Primordial interface for maintaining application cache. In contrast to other cache providers, this type of cache ensures type checking and provides efficient caching for a distributed system.

Implementations should provide appropriate methods to set their cache parameters (e.g. time-to-live) and/or force removal of entities before their normal expiration. These are not part of the AuthorizationCache interface contract because they vary depending on the type of caching system used (in-memory, disk, cluster, hybrid etc.).

Caching is generally only required in applications which do not maintain server-side state, such as remote clients or web services. The authentication credentials are then presented on each invocation and the overhead of accessing a database or other persistent storage mechanism to validate would be excessive. In this case, you would configure a cache to store the UserDetails information rather than loading it each time.

Note that the interface is declared abstract which doesn't make any sense. But, it's just to notify the programmer that this type is not an initialization/autowiring candidate. Interfaces/Classes extending/implementing this contract must be initialized so as to support multiple types and instances of cache per container (as suited).

Since:

November 10^th, 2015

Author:

Abhinav Rai

Method Summary

Modifier and Type	Method and Description
void	evictFromCache(K key) Removes the specified entry from the cache.
void	flush() Flushes the application cache (doesn't destroy it).
V	getFromCache(K key) Obtains a stored entry from the cache.
void	initialize() Initializes the application cache (doesn't create it).
void	putInCache(K key, V entry) Places an entry in the cache.

Methods inherited from interface org.springframework.beans.factory.InitializingBean

afterPropertiesSet

Methods inherited from interface org.springframework.beans.factory.DisposableBean

destroy

Method Detail

initialize

void initialize()

Initializes the application cache (doesn't create it). Can make use of a data-store for pre-fetching already stored application data (if required) typically upon container restart.

Each type of application cache is initialized separately in order to maintain sanity and usage simplicity. Thus, please be advised that a cache type must be instantiated & initialized manually before use (manually just means that extra code is required for the same).

getFromCache

V getFromCache(K key)

Obtains a stored entry from the cache. Implementations must make sure not to throw an exception even if one occurs here.

Parameters:

key - the unique identifier to use for fetching the entry; be advised that the same identifier must be used for saving the details into the cache

Returns:

a populated entry object containing enough information to facilitate the function it is required for; if none is found

putInCache

void putInCache(K key,
                V entry)

Places an entry in the cache. The key is the identifier used to subsequently retrieve the entry.

Parameters:

key - the key corresponding to which entry must be stored in the cache

entry - the object entry to place into the cache

evictFromCache

void evictFromCache(K key)

Removes the specified entry from the cache. The key is the identifier used to remove the entry. If the entry is not found, the method should simply return (not throw an exception).

Some cache implementations may not support eviction from the cache, in which case they should provide appropriate behavior to alter the token in either its documentation, via an exception, or through a log message.

Parameters:

key - the predefined key/identifier for evicting an entry from the cache

flush

void flush()

Flushes the application cache (doesn't destroy it). Note that flushing an application cache doesn't mean it is destroyed. It may just be reduced in size or cleared in order to re-claim memory.

Each type of application cache is flushed separately in order to maintain sanity and usage simplicity. Thus, please be advised that a cache type must be flushed & manually whenever required (manually just means that extra code is required for the same).