Class WeakObjectRegistry<K, E extends K>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractSet<E>

org.eclipse.rdf4j.sail.memory.model.WeakObjectRegistry<K,E>

All Implemented Interfaces:

Iterable<E>, Collection<E>, Set<E>

public class WeakObjectRegistry<K, E extends K>
extends AbstractSet<E>

An object registry that uses weak references to keep track of the stored objects. The registry can be used to retrieve stored objects using another, equivalent object. As such, it can be used to prevent the use of duplicates in another data structure, reducing memory usage. The objects that are being stored should properly implement the Object.equals(Object) and Object.hashCode() methods.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	WeakObjectRegistry.AdderBasedReadWriteLock
static class	WeakObjectRegistry.AutoCloseableIterator<E>

Field Summary

Fields

Modifier and Type	Field	Description
private final WeakObjectRegistry.AdderBasedReadWriteLock[]	locks
private static final org.slf4j.Logger	logger
private final Map<E, WeakReference<E>>[]	objectMap	The hash map that is used to store the objects.

Constructor Summary

Constructors

Constructor	Description
WeakObjectRegistry()	Constructs a new, empty object registry.
WeakObjectRegistry(int cacheSize, Collection<? extends E> c)	Constructs a new WeakObjectRegistry containing the elements in the specified collection.

Method Summary

Modifier and Type	Method	Description
boolean	add(E object)
void	clear()
WeakObjectRegistry.AutoCloseableIterator<E>	closeableIterator()
boolean	contains(Object key)
E	get(K key)	Retrieves the stored object that is equal to the supplied key object.
private int	getIndex(Object key)
E	getOrAdd(K key, Supplier<E> supplier)
Iterator<E>	iterator()
boolean	remove(Object object)
int	size()

Methods inherited from class AbstractSet

equals, hashCode, removeAll

Methods inherited from class AbstractCollection

addAll, containsAll, isEmpty, retainAll, toArray, toArray, toString

Methods inherited from class Object

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

Methods inherited from interface Collection

parallelStream, removeIf, stream, toArray

Methods inherited from interface Iterable

forEach

Methods inherited from interface Set

addAll, containsAll, isEmpty, retainAll, spliterator, toArray, toArray

Field Details

logger

private static final org.slf4j.Logger logger

objectMap

private final Map<E extends K, WeakReference<E extends K>>[] objectMap

The hash map that is used to store the objects.

locks

private final WeakObjectRegistry.AdderBasedReadWriteLock[] locks

Constructor Details

WeakObjectRegistry

public WeakObjectRegistry()

Constructs a new, empty object registry.

WeakObjectRegistry

public WeakObjectRegistry(int cacheSize,
 Collection<? extends E> c)

Constructs a new WeakObjectRegistry containing the elements in the specified collection.

Parameters:

c - The collection whose elements are to be placed into this object registry.

Throws:

NullPointerException - If the specified collection is null.

Method Details

get

public E get(K key)

Retrieves the stored object that is equal to the supplied key object.

Parameters:

key - The object that should be used as the search key for the operation.

Returns:

A stored object that is equal to the supplied key, or null if no such object was found.

getIndex

private int getIndex(Object key)

closeableIterator

public WeakObjectRegistry.AutoCloseableIterator<E> closeableIterator()

iterator

public Iterator<E> iterator()

Specified by:

iterator in interface Collection<K>

Specified by:

iterator in interface Iterable<K>

Specified by:

iterator in interface Set<K>

Specified by:

iterator in class AbstractCollection<E extends K>

size

public int size()

Specified by:

size in interface Collection<K>

Specified by:

size in interface Set<K>

Specified by:

size in class AbstractCollection<E extends K>

contains

public boolean contains(Object key)

Specified by:

contains in interface Collection<K>

Specified by:

contains in interface Set<K>

Overrides:

contains in class AbstractCollection<E extends K>

add

public boolean add(E object)

Specified by:

add in interface Collection<K>

Specified by:

add in interface Set<K>

Overrides:

add in class AbstractCollection<E extends K>

getOrAdd

public E getOrAdd(K key,
 Supplier<E> supplier)

remove

public boolean remove(Object object)

Specified by:

remove in interface Collection<K>

Specified by:

remove in interface Set<K>

Overrides:

remove in class AbstractCollection<E extends K>

clear

public void clear()

Specified by:

clear in interface Collection<K>

Specified by:

clear in interface Set<K>

Overrides:

clear in class AbstractCollection<E extends K>