org.jpox.store.poid
Class AbstractPoidGenerator

java.lang.Object
  org.jpox.store.poid.AbstractPoidGenerator

All Implemented Interfaces:

javax.jdo.datastore.Sequence, PoidGenerator

Direct Known Subclasses:

AbstractDatastorePoidGenerator, AbstractUIDPoidGenerator

public abstract class AbstractPoidGenerator
extends java.lang.Object
implements PoidGenerator

Abstract POID generator.

Version:

$Revision: 1.5 $

Field Summary

protected int	defaultBlockSize Default block size
protected static Localiser	LOCALISER Localisation of messages
protected java.lang.String	name Symbolic name for the sequence.
protected PoidBlock	poidBlock The current block of ids that have been reserved.
protected java.util.Properties	properties Properties controlling the generator behaviour.

Constructor Summary

AbstractPoidGenerator(java.lang.String name, java.util.Properties props)
Constructor.

Method Summary

void	allocate(int additional) Method to allocate a number of values into the block.
protected boolean	createRepository() Method to create any needed repository for the ids.
java.lang.Object	current() Accessor for the current value allocated.
long	currentValue() Accessor for the current element in the sequence as a long.
java.lang.String	getName() Accessor for the symbolic name for this generator.
java.lang.Object	next() Get next value from the reserved block of values.
long	nextValue() Accessor for the next element in the sequence as a long.
protected PoidBlock	obtainPoidBlock() Get a new PoidBlock with the default number of ids.
protected PoidBlock	obtainPoidBlock(int number) Get a new PoidBlock with the specified number of ids.
protected boolean	requiresRepository() Indicator for whether the generator requires its own repository.
protected PoidBlock	reserveBlock() Method to reserve a default sized block of identities.
protected abstract PoidBlock	reserveBlock(long size) Method to reserve a blobk of "size" ids.

Methods inherited from class java.lang.Object

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

Field Detail

LOCALISER

protected static final Localiser LOCALISER

Localisation of messages

name

protected java.lang.String name

Symbolic name for the sequence.

properties

protected java.util.Properties properties

Properties controlling the generator behaviour.

defaultBlockSize

protected int defaultBlockSize

Default block size

poidBlock

protected PoidBlock poidBlock

The current block of ids that have been reserved.

Constructor Detail

AbstractPoidGenerator

public AbstractPoidGenerator(java.lang.String name,
                             java.util.Properties props)

Constructor.

Parameters:

name - Symbolic name for this generator

props - Properties controlling the behaviour of the generator (or null if not required).

Method Detail

getName

public java.lang.String getName()

Accessor for the symbolic name for this generator.

Specified by:

getName in interface javax.jdo.datastore.Sequence

Returns:

Symbolic name for the generator.

next

public java.lang.Object next()

Get next value from the reserved block of values.

Specified by:

next in interface javax.jdo.datastore.Sequence

Returns:

The next value

current

public java.lang.Object current()

Accessor for the current value allocated. Returns null if none are allocated

Specified by:

current in interface javax.jdo.datastore.Sequence

Returns:

The current value

nextValue

public long nextValue()

Accessor for the next element in the sequence as a long.

Specified by:

nextValue in interface javax.jdo.datastore.Sequence

Returns:

The next element

Throws:

javax.jdo.JDODataStoreException - Thrown if not numeric

currentValue

public long currentValue()

Accessor for the current element in the sequence as a long.

Specified by:

currentValue in interface javax.jdo.datastore.Sequence

Returns:

The current element

Throws:

javax.jdo.JDODataStoreException - Thrown if not numeric

allocate

public void allocate(int additional)

Method to allocate a number of values into the block. If the block already exists and has remaining values, the additional values are added to the block.

Specified by:

allocate in interface javax.jdo.datastore.Sequence

Parameters:

additional - The number to allocate

obtainPoidBlock

protected PoidBlock obtainPoidBlock()

Get a new PoidBlock with the default number of ids.

Returns:

the PoidBlock

obtainPoidBlock

protected PoidBlock obtainPoidBlock(int number)

Get a new PoidBlock with the specified number of ids.

Parameters:

number - The number of additional ids required

Returns:

the PoidBlock

reserveBlock

protected PoidBlock reserveBlock()

Method to reserve a default sized block of identities.

Returns:

The reserved block

reserveBlock

protected abstract PoidBlock reserveBlock(long size)

Method to reserve a blobk of "size" ids.

Parameters:

size - Number of ids to reserve

Returns:

The allocated block

requiresRepository

protected boolean requiresRepository()

Indicator for whether the generator requires its own repository. AbstractPoidGenerator returns false and this should be overridden by all generators requiring a repository.

Returns:

Whether a repository is required.

createRepository

protected boolean createRepository()

Method to create any needed repository for the ids. AbstractPoidGenerator just returns true and should be overridden by any implementing generator requiring its own repository.

Returns:

If all is ready for use