Package com.tangosol.util

Class InflatableCollection

java.lang.Object

java.util.AbstractCollection

com.tangosol.util.InflatableCollection

All Implemented Interfaces:

Iterable, Collection

Direct Known Subclasses:

InflatableList, InflatableSet

public abstract class InflatableCollection
extends AbstractCollection

A Collection implementation which optimizes memory consumption for collections that often contain just a single value. This implementation also reduces contention for read operations (e.g. contains, iterator, etc.)

Since:

Coherence 3.6

Author:

ch 2009.11.22

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static interface	InflatableCollection.InflatedCollection	A marker interface which is used to identify internally inflated Collections.

Field Summary

Fields

Modifier and Type	Field	Description
protected Object	m_oValue	Holds NO_VALUE, a single value, or an InflatedCollection of values.
protected static final Object	NO_VALUE	A marker value indicating that the single value has not been initialized.
protected static final AtomicReferenceFieldUpdater<InflatableCollection,Object>	VALUE_UPDATER	Atomic updater for collection values.

Constructor Summary

Constructors

Constructor	Description
InflatableCollection()

Method Summary

Modifier and Type	Method	Description
boolean	add(Object o)
void	clear()
boolean	contains(Object o)
boolean	equals(Object o)
int	hashCode()
protected abstract InflatableCollection.InflatedCollection	instantiateCollection()	Factory method used to create a new Collection.
Iterator	iterator()
boolean	remove(Object o)
boolean	removeAll(Collection c)
boolean	retainAll(Collection c)
int	size()
Object[]	toArray()
Object[]	toArray(Object[] ao)

Methods inherited from class java.util.AbstractCollection

addAll, containsAll, isEmpty, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Collection

parallelStream, removeIf, spliterator, stream, toArray

Methods inherited from interface java.lang.Iterable

forEach

Field Details

NO_VALUE

protected static final Object NO_VALUE

A marker value indicating that the single value has not been initialized.

VALUE_UPDATER

protected static final AtomicReferenceFieldUpdater<InflatableCollection,Object> VALUE_UPDATER

Atomic updater for collection values. Static atomic field updater rather than AtomicReference is shared to reduce memory footprint of each InflatableCollection instance. (COH-9262)

m_oValue

protected volatile Object m_oValue

Holds NO_VALUE, a single value, or an InflatedCollection of values.

Constructor Details

InflatableCollection

public InflatableCollection()

Method Details

equals

public boolean equals(Object o)

Specified by:

equals in interface Collection

Overrides:

equals in class Object

hashCode

public int hashCode()

Specified by:

hashCode in interface Collection

Overrides:

hashCode in class Object

add

public boolean add(Object o)

Specified by:

add in interface Collection

Overrides:

add in class AbstractCollection

remove

public boolean remove(Object o)

Specified by:

remove in interface Collection

Overrides:

remove in class AbstractCollection

removeAll

public boolean removeAll(Collection c)

Specified by:

removeAll in interface Collection

Overrides:

removeAll in class AbstractCollection

retainAll

public boolean retainAll(Collection c)

Specified by:

retainAll in interface Collection

Overrides:

retainAll in class AbstractCollection

clear

public void clear()

Specified by:

clear in interface Collection

Overrides:

clear in class AbstractCollection

contains

public boolean contains(Object o)

Specified by:

contains in interface Collection

Overrides:

contains in class AbstractCollection

iterator

public Iterator iterator()

Specified by:

iterator in interface Collection

Specified by:

iterator in interface Iterable

Specified by:

iterator in class AbstractCollection

size

public int size()

Specified by:

size in interface Collection

Specified by:

size in class AbstractCollection

toArray

public Object[] toArray()

Specified by:

toArray in interface Collection

Overrides:

toArray in class AbstractCollection

toArray

public Object[] toArray(Object[] ao)

Specified by:

toArray in interface Collection

Overrides:

toArray in class AbstractCollection

instantiateCollection

protected abstract InflatableCollection.InflatedCollection instantiateCollection()

Factory method used to create a new Collection. The returned Collection must provide a "safe" iterator.

Returns:

a "real" implementation to use if this collection is expanded