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com.tangosol.util
Class InflatableCollection

java.lang.Object
java.util.AbstractCollection
com.tangosol.util.InflatableCollection

All Implemented Interfaces:

java.lang.Iterable, java.util.Collection

Direct Known Subclasses:

InflatableList, InflatableSet

public abstract class InflatableCollection

extends java.util.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

protected static interface

InflatableCollection.InflatedCollection A marker interface which is used to identify internally inflated Collections.

Field Summary

protected java.lang.Object	m_oValue Holds NO_VALUE, a single value, or an InflatedCollection of values.
protected static java.lang.Object	NO_VALUE A marker value indicating that the single value has not been initialized.
protected static java.util.concurrent.atomic.AtomicReferenceFieldUpdater	VALUE_UPDATER Atomic updater for collection values.

Constructor Summary

InflatableCollection()

Method Summary

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

Methods inherited from class java.util.AbstractCollection

addAll, containsAll, isEmpty, toString

Field Detail

NO_VALUE

protected static final java.lang.Object NO_VALUE

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

VALUE_UPDATER

protected static final java.util.concurrent.atomic.AtomicReferenceFieldUpdater 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 java.lang.Object m_oValue

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

Constructor Detail

InflatableCollection

public InflatableCollection()

Method Detail

equals

public boolean equals(java.lang.Object o)

hashCode

public int hashCode()

add

public boolean add(java.lang.Object o)

Specified by:

add in interface java.util.Collection

Overrides:

add in class java.util.AbstractCollection

remove

public boolean remove(java.lang.Object o)

Specified by:

remove in interface java.util.Collection

Overrides:

remove in class java.util.AbstractCollection

removeAll

public boolean removeAll(java.util.Collection c)

Specified by:

removeAll in interface java.util.Collection

Overrides:

removeAll in class java.util.AbstractCollection

retainAll

public boolean retainAll(java.util.Collection c)

Specified by:

retainAll in interface java.util.Collection

Overrides:

retainAll in class java.util.AbstractCollection

clear

public void clear()

Specified by:

clear in interface java.util.Collection

Overrides:

clear in class java.util.AbstractCollection

contains

public boolean contains(java.lang.Object o)

Specified by:

contains in interface java.util.Collection

Overrides:

contains in class java.util.AbstractCollection

iterator

public java.util.Iterator iterator()

Specified by:

iterator in interface java.lang.Iterable

Specified by:

iterator in interface java.util.Collection

Specified by:

iterator in class java.util.AbstractCollection

size

public int size()

Specified by:

size in interface java.util.Collection

Specified by:

size in class java.util.AbstractCollection

toArray

public java.lang.Object[] toArray()

Specified by:

toArray in interface java.util.Collection

Overrides:

toArray in class java.util.AbstractCollection

toArray

public java.lang.Object[] toArray(java.lang.Object[] ao)

Specified by:

toArray in interface java.util.Collection

Overrides:

toArray in class java.util.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

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