com.gentlyweb.utils

Interface MultipleObjectCacheManager

public interface MultipleObjectCacheManager

This interface should be implemented by classes that contain X number of publicly available ObjectCaches, it provides methods that allow applications to control the caches without understanding what is inside the cache.

All of the methods in this interface are optional and if not supported then implementing classes should throw UnsupportedOperationException.

This interface mirrors ObjectCacheManager but each method (where appropriate) takes a key object to tell the implementing class which cache it wants the operation to occur on.

Method Summary

Modifier and Type	Method and Description
int	capacity(Object key) Return the current capacity of the cache, it should basically be (max size - current size).
void	flush(Object key) Let the object cache be flushed.
boolean	isEmpty(Object key) Return whether the cache is empty or not.
void	merge(Object key, ObjectCache cache) Merge the current cache with another.
void	putAll(Object key, Map map) Add all the entries in the Map to cache.
void	resize(Object key, int size) Resize the cache to a particular size, if the size is actually bigger than the current size then this operation should not touch the cached objects, if the size is less then the cache should be reduced in size using the current policy until the size is reached.
void	setMaxSize(Object key, int size) Set the maximum size of the cache.
void	setPolicy(Object key, int policy) Set the policy for managing the cache, should be one of: ObjectCache.OLDEST, ObjectCache.YOUNGEST, ObjectCache.RANDOM.
void	toMap(Object object, Map map) Get all the entries in the cache as a Map of key to value.

Method Detail

flush

void flush(Object key)

Let the object cache be flushed.

Parameters:

key - The key to identify the particular cache.

setMaxSize

void setMaxSize(Object key,
                int size)

Set the maximum size of the cache.

Parameters:

key - The key to identify the particular cache.

size - The maximum size.

resize

void resize(Object key,
            int size)

Resize the cache to a particular size, if the size is actually bigger than the current size then this operation should not touch the cached objects, if the size is less then the cache should be reduced in size using the current policy until the size is reached. Either way the maximum size should be set to this value.

Parameters:

key - The key to identify the particular cache.

size - The new size.

capacity

int capacity(Object key)

Return the current capacity of the cache, it should basically be (max size - current size).

Parameters:

key - The key to identify the particular cache.

Returns:

The current number of items that can be added until the cache reaches it's maximum size.

isEmpty

boolean isEmpty(Object key)

Return whether the cache is empty or not.

Parameters:

key - The key to identify the particular cache.

Returns:

true if the cache is empty, false if it has entries.

toMap

void toMap(Object object,
           Map map)

Get all the entries in the cache as a Map of key to value.

Parameters:

key - The key to identify the particular cache.

map - The Map that should be populated with the key/values in the cache.

merge

void merge(Object key,
           ObjectCache cache)

Merge the current cache with another.

Parameters:

key - The key to identify the particular cache.

cache - The cache to merge.

putAll

void putAll(Object key,
            Map map)

Add all the entries in the Map to cache.

Parameters:

key - The key to identify the particular cache.

map - The Map to get key/values from.

setPolicy

void setPolicy(Object key,
               int policy)

Set the policy for managing the cache, should be one of: ObjectCache.OLDEST, ObjectCache.YOUNGEST, ObjectCache.RANDOM.

Parameters:

key - The key to identify the particular cache.

policy - The policy.