org.datanucleus.store.valuegenerator

Class AbstractGenerator<T>

java.lang.Object

org.datanucleus.store.valuegenerator.AbstractGenerator<T>

All Implemented Interfaces:

ValueGenerator<T>

Direct Known Subclasses:

AbstractConnectedGenerator, AbstractUUIDGenerator, AUIDGenerator, TimestampGenerator, TimestampValueGenerator, UUIDGenerator, UUIDObjectGenerator

public abstract class AbstractGenerator<T>
extends Object
implements ValueGenerator<T>

Abstract value generator.

Field Summary

Fields

Modifier and Type	Field and Description
protected int	allocationSize Allocation size
protected ValueGenerationBlock<T>	block The current block of values that have been reserved.
protected int	initialValue Initial value (of the first id).
protected String	name Symbolic name for the value generator.
protected StoreManager	storeMgr

Fields inherited from interface org.datanucleus.store.valuegenerator.ValueGenerator

PROPERTY_CATALOG_NAME, PROPERTY_CLASS_NAME, PROPERTY_COLUMN_NAME, PROPERTY_FIELD_NAME, PROPERTY_KEY_CACHE_SIZE, PROPERTY_KEY_DATABASE_CACHE_SIZE, PROPERTY_KEY_INITIAL_VALUE, PROPERTY_KEY_MAX_VALUE, PROPERTY_KEY_MIN_VALUE, PROPERTY_ROOT_CLASS_NAME, PROPERTY_SCHEMA_NAME, PROPERTY_SEQUENCE_NAME, PROPERTY_SEQUENCETABLE_CATALOG, PROPERTY_SEQUENCETABLE_NAME_COLUMN, PROPERTY_SEQUENCETABLE_NEXTVAL_COLUMN, PROPERTY_SEQUENCETABLE_SCHEMA, PROPERTY_SEQUENCETABLE_TABLE, PROPERTY_TABLE_NAME

Constructor Summary

Constructors

Constructor and Description
AbstractGenerator(StoreManager storeMgr, String name) Constructor.

Method Summary

Modifier and Type	Method and Description
void	allocate(int additional) Method to allocate a number of values into the block.
T	current() Accessor for the current value allocated.
long	currentValue() Accessor for the current element as a long.
String	getName() Accessor for the symbolic name for this generator.
T	next() Get next value from the reserved block of values.
long	nextValue() Accessor for the next element as a long.
protected ValueGenerationBlock<T>	obtainGenerationBlock() Get a new block with the default number of ids.
protected ValueGenerationBlock<T>	obtainGenerationBlock(int number) Get a new block with the specified number of ids.
protected ValueGenerationBlock<T>	reserveBlock() Method to reserve a default sized block of values.
protected abstract ValueGenerationBlock<T>	reserveBlock(long size) Method to reserve a block of "size" values.

Methods inherited from class java.lang.Object

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

Field Detail

storeMgr

protected StoreManager storeMgr

name

protected String name

Symbolic name for the value generator.

allocationSize

protected int allocationSize

Allocation size

initialValue

protected int initialValue

Initial value (of the first id).

block

protected ValueGenerationBlock<T> block

The current block of values that have been reserved.

Constructor Detail

AbstractGenerator

public AbstractGenerator(StoreManager storeMgr,
                         String name)

Constructor.

Parameters:

storeMgr - Store Manager

name - Symbolic name for this generator

Method Detail

getName

public String getName()

Accessor for the symbolic name for this generator.

Returns:

Symbolic name for the generator.

next

public T next()

Get next value from the reserved block of values.

Specified by:

next in interface ValueGenerator<T>

Returns:

The next value

current

public T current()

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

Specified by:

current in interface ValueGenerator<T>

Returns:

The current value

nextValue

public long nextValue()

Accessor for the next element as a long.

Specified by:

nextValue in interface ValueGenerator<T>

Returns:

The next element

Throws:

NucleusDataStoreException - Thrown if not numeric

currentValue

public long currentValue()

Accessor for the current element as a long.

Specified by:

currentValue in interface ValueGenerator<T>

Returns:

The current element

Throws:

NucleusDataStoreException - 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 ValueGenerator<T>

Parameters:

additional - The number to allocate

obtainGenerationBlock

protected ValueGenerationBlock<T> obtainGenerationBlock()

Get a new block with the default number of ids.

Returns:

the block

obtainGenerationBlock

protected ValueGenerationBlock<T> obtainGenerationBlock(int number)

Get a new block with the specified number of ids.

Parameters:

number - The number of additional ids required

Returns:

the block

reserveBlock

protected ValueGenerationBlock<T> reserveBlock()

Method to reserve a default sized block of values.

Returns:

The reserved block

reserveBlock

protected abstract ValueGenerationBlock<T> reserveBlock(long size)

Method to reserve a block of "size" values.

Parameters:

size - Number of values to reserve

Returns:

The allocated block