net.obsearch.cache
Class OBCacheLong<O>

java.lang.Object
  java.util.AbstractMap<K,V>
      java.util.HashMap<K,V>
          java.util.LinkedHashMap<K,O>
              net.obsearch.cache.AbstractOBCache<Long,O>
                  net.obsearch.cache.OBCacheLong<O>

Type Parameters:

O - The type of object that will be stored in the Cache.

All Implemented Interfaces:

Serializable, Cloneable, Map<Long,O>

public final class OBCacheLong<O>
extends AbstractOBCache<Long,O>

By using soft references, an OB cache is implemented The garbage collector decides based on the access patterns of each reference, which elements are released and which are kept. The cache controls the loading of items. For this purpose an OBCacheLoader is provided to control the loading and instantiation of the objects from secondary storage. That is why this cache does not have a put method. It assumes that all the requested items exist in secondary storage otherwise it returns an error. Loading operations generate a lock but reading operations do not generate any locks.

Since:

0.7

Author:

Arnoldo Jose Muller Molina

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>

Field Summary

Fields inherited from class net.obsearch.cache.AbstractOBCache

cacheSize

Constructor Summary

OBCacheLong(OBCacheHandlerLong<O> handler, int cacheSize)
Initialize the cache with the given amount of elements.

Method Summary

void	clearAll() Makes sure the cache is cleaned and each object is stored.
O	get(long id) Gets the given object, returns null if the object is not found.
protected boolean	removeEldestEntry(Map.Entry<Long,O> eldest)

Methods inherited from class java.util.LinkedHashMap

clear, containsValue, get

Methods inherited from class java.util.HashMap

clone, containsKey, entrySet, isEmpty, keySet, put, putAll, remove, size, values

Methods inherited from class java.util.AbstractMap

equals, hashCode, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

containsKey, entrySet, equals, hashCode, isEmpty, keySet, put, putAll, remove, size, values

Constructor Detail

OBCacheLong

public OBCacheLong(OBCacheHandlerLong<O> handler,
                   int cacheSize)
            throws OBException

Initialize the cache with the given amount of elements.

Parameters:

size - Number of elements that the internal hash table will be initialized with.

Throws:

OBException

Method Detail

get

public O get(long id)
      throws OutOfRangeException,
             OBException,
             InstantiationException,
             IllegalAccessException

Gets the given object, returns null if the object is not found.

Parameters:

id - internal id.

Returns:

null if no object is found

Throws:

OutOfRangeException

OBException

InstantiationException

IllegalAccessException

removeEldestEntry

protected boolean removeEldestEntry(Map.Entry<Long,O> eldest)

Overrides:

removeEldestEntry in class LinkedHashMap<Long,O>

clearAll

public void clearAll()
              throws OBException

Description copied from class: AbstractOBCache

Makes sure the cache is cleaned and each object is stored.

Specified by:

clearAll in class AbstractOBCache<Long,O>

Throws:

OBException