Package com.github.jasminb.jsonapi

Class ResourceCache

java.lang.Object

com.github.jasminb.jsonapi.ResourceCache

public class ResourceCache
extends Object

Resource caching provider.

Cache implementation is based on thread-local variables. In order to use cache in a thread, init() method must be called. When cache is no longer needed, clear() method should be used to perform thread local cleanup.

Cache can be locked by invoking lock(), after cache is locked, no items will be cached, and calling any cache method will be a no-op. To unlock cache and make it accept cache calls again, unlock() method must be invoked.

If cache is used in recursive calls, it is safe to call init() and clear() multiple times. Init call will not purge current cache state in case it is called recursively. Clear call will clear cache state only if recursion exited (initDepth == 0).

Author:

jbegic

Constructor Summary

Constructors

Constructor	Description
ResourceCache()

Method Summary

Modifier and Type	Method	Description
void	cache(String identifier, Object resource)	Adds resource to cache.
void	cache(Map<String,Object> resources)	Adds multiple resources to cache.
void	clear()	Clears current thread scope state.
boolean	contains(String identifier)	Checks if resource with given identifier is cached.
Object	get(String identifier)	Returns cached resource or null if resource was not found in cache.
void	init()	Initialises cache for current thread-scope.
void	lock()	Locks this cache instance for thread scope that method was invoked in.
void	unlock()	Unlocks this cache instance for thread scope that method was invoked in.

Methods inherited from class java.lang.Object

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

Constructor Detail

ResourceCache

public ResourceCache()

Method Detail

init

public void init()

Initialises cache for current thread-scope.

clear

public void clear()

Clears current thread scope state.

Throws:

IllegalStateException - in case init() was not called

cache

public void cache(Map<String,Object> resources)

Adds multiple resources to cache.

Parameters:

resources - items to add

Throws:

IllegalStateException - in case init() was not called

cache

public void cache(String identifier,
                  Object resource)

Adds resource to cache.

Parameters:

identifier - resource identifier

resource - resource

Throws:

IllegalStateException - in case init() was not called

get

public Object get(String identifier)

Returns cached resource or null if resource was not found in cache.

Parameters:

identifier - resource identifier

Returns:

cached resource or null

contains

public boolean contains(String identifier)

Checks if resource with given identifier is cached.

Parameters:

identifier - resource identifier

Returns:

true if resource is cached, else false

Throws:

IllegalStateException - in case init() was not called

lock

public void lock()

Locks this cache instance for thread scope that method was invoked in.

After invoking this method, all cache attempts will be no-op.

Throws:

IllegalStateException - in case init() was not called

unlock

public void unlock()

Unlocks this cache instance for thread scope that method was invoked in.

After invoking this method. Cache calls will cache items accordingly.