com.orientechnologies.common.collection.closabledictionary

Class OClosableLinkedContainer<K,V extends OClosableItem>

java.lang.Object

com.orientechnologies.common.collection.closabledictionary.OClosableLinkedContainer<K,V>

Type Parameters:

K - Key associated with entry stored inside of container.

V - Value which may be in open/closed stated and associated with key.

public class OClosableLinkedContainer<K,V extends OClosableItem>
extends Object

Container for the elements which may be in open/closed state. But only limited amount of elements are hold by given container may be in open state.

Elements may be added in this container only in open state,as result after addition of some elements other rarely used elements will be closed.

When you want to use elements from container you should acquire them acquire(Object). So element still will be inside of container but in acquired state. As result it will not be automatically closed when container will try to close rarely used items.

Container uses LRU eviction policy to choose item to be closed.

When you finish to work with element from container you should release (@link release(OClosableEntry)) element back to container.

Constructor Summary

Constructors

Constructor and Description
OClosableLinkedContainer(int openLimit) Creates new instance of container and set limit of open files which may be hold by container.

Method Summary

Modifier and Type	Method and Description
OClosableEntry<K,V>	acquire(K key) Acquires item associated with passed in key in container.
void	add(K key, V item) Adds item to the container.
void	clear() Clears all content.
boolean	close(K key) Closes item related to passed in key.
V	get(K key) Returns item without acquiring it.
void	release(OClosableEntry<K,V> entry) Releases item acquired by call of acquire(Object) method.
V	remove(K key) Removes item associated with passed in key.
OClosableEntry<K,V>	tryAcquire(K key)

Methods inherited from class java.lang.Object

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

Constructor Detail

OClosableLinkedContainer

public OClosableLinkedContainer(int openLimit)

Creates new instance of container and set limit of open files which may be hold by container.

Parameters:

openLimit - Limit of open files hold by container.

Method Detail

add

public void add(K key,
                V item)
         throws InterruptedException

Adds item to the container. Item should be in open state.

Parameters:

key - Key associated with given item.

item - Item associated with passed in key.

Throws:

InterruptedException

remove

public V remove(K key)

Removes item associated with passed in key.

Parameters:

key - Key associated with item to remove.

Returns:

Removed item.

acquire

public OClosableEntry<K,V> acquire(K key)
                            throws InterruptedException

Acquires item associated with passed in key in container. It is guarantied that item will not be closed if limit of open items will be exceeded and container will close rarely used items.

Parameters:

key - Key associated with item

Returns:

Acquired item if key exists into container or null if there is no item associated with given container

Throws:

InterruptedException

tryAcquire

public OClosableEntry<K,V> tryAcquire(K key)
                               throws InterruptedException

Throws:

InterruptedException

release

public void release(OClosableEntry<K,V> entry)

Releases item acquired by call of acquire(Object) method. After this call container is free to close given item if limit of open files exceeded and this item is rarely used.

Parameters:

entry - Entry to release

get

public V get(K key)

Returns item without acquiring it. State of item is not guarantied in such case.

Parameters:

key - Key associated with required item.

Returns:

Item associated with given key.

clear

public void clear()

Clears all content.

close

public boolean close(K key)

Closes item related to passed in key. Item will be closed if it exists and is not acquired.

Parameters:

key - Key related to item that has going to be closed.

Returns:

true if item was closed and false otherwise.