org.eclipse.emf.common.util

Class Pool.AccessUnit<E>

java.lang.Object

org.eclipse.emf.common.util.Pool.AccessUnit<E>

Direct Known Subclasses:

Pool.ObjectAccessUnit, SegmentSequence.SegmentSequencePool.AccessUnitBase, SegmentSequence.StringArrayPool.AccessUnitBase, URI.URIPool.URIPoolAccessUnitBase

Enclosing class:

Pool<E>

protected abstract static class Pool.AccessUnit<E>
extends java.lang.Object

An access unit is used during access to the pool. It contains a buffer for processing the collision values at a particular index in the WeakInterningHashSet.entries. Access units are recycled for reuse in subsequent accesses. Because of shared multi-threaded read access, there may be as many instances as there are threads simultaneously accessing the pool.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	Pool.AccessUnit.Queue<E>

Field Summary

Fields

Modifier and Type	Field and Description
protected WeakInterningHashSet.Entry<E>	createdEntry
protected WeakInterningHashSet.Entry<E>[]	entries
protected int	hashCode The hash code of the object being accessed.
protected int	matchingIndex This records during match() the matching index.
protected Pool.AccessUnit<E>	next Access units are chained via this link.
protected Pool.AccessUnit.Queue<E>	queue Access units are maintained for recycled use in this queue.
protected java.lang.Object[]	values
protected int	valuesLength This records the number of values cached for this access.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AccessUnit(Pool.AccessUnit.Queue<E> queue)

Method Summary

Modifier and Type	Method and Description
void	add(E value, WeakInterningHashSet.Entry<E> entry) Add a value to the values incrementing the valuesLength.
protected WeakInterningHashSet.Entry<E>	getEntry()
E	getInternalizedValue() Gets the value that should be added to the pool.
protected abstract E	getValue()
E	match() Used to return a value from among the values that matches(Object) the value being accessed.
protected boolean	matches(E value) Used to determine whether the given value from the pool is equal to the value being accessed.
boolean	rematches(E value, WeakInterningHashSet.Entry<E> entry) Used to determine whether the given value from the pool is equal to the value being accessed.
void	reset(boolean isExclusive) Prepare the access unit for reuse.
protected abstract boolean	setArbitraryValue(java.lang.Object value)
protected abstract void	setValue(E value)

Methods inherited from class java.lang.Object

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

Field Detail

queue

protected final Pool.AccessUnit.Queue<E> queue

Access units are maintained for recycled use in this queue.

next

protected Pool.AccessUnit<E> next

Access units are chained via this link.

hashCode

protected int hashCode

The hash code of the object being accessed.

values

protected java.lang.Object[] values

valuesLength

protected int valuesLength

This records the number of values cached for this access.

matchingIndex

protected int matchingIndex

This records during match() the matching index.

createdEntry

protected WeakInterningHashSet.Entry<E> createdEntry

entries

protected WeakInterningHashSet.Entry<E>[] entries

Constructor Detail

AccessUnit

protected AccessUnit(Pool.AccessUnit.Queue<E> queue)

Method Detail

getValue

protected abstract E getValue()

setValue

protected abstract void setValue(E value)

setArbitraryValue

protected abstract boolean setArbitraryValue(java.lang.Object value)

getEntry

protected WeakInterningHashSet.Entry<E> getEntry()

getInternalizedValue

public E getInternalizedValue()

Gets the value that should be added to the pool. This can be specialized to internalized the value, e.g., to make a copy that uses minimal storage or is read only.

matches

protected boolean matches(E value)

Used to determine whether the given value from the pool is equal to the value being accessed. The default implementation uses Object.equals(Object).

rematches

public final boolean rematches(E value,
                               WeakInterningHashSet.Entry<E> entry)

Used to determine whether the given value from the pool is equal to the value being accessed. It is called when double checking the match after acquiring the write lock so it can safely any values previous cached.

match

public E match()

Used to return a value from among the values that matches(Object) the value being accessed. Returns null if there is no such matching value.

add

public void add(E value,
                WeakInterningHashSet.Entry<E> entry)

Add a value to the values incrementing the valuesLength.

reset

public void reset(boolean isExclusive)

Prepare the access unit for reuse. In particular remove the hard references to each element in both the values and entries and then reset the valuesLength to 0