org.apache.avalon.excalibur.datasource.ids

Class AbstractDataSourceBlockIdGenerator

java.lang.Object

org.apache.avalon.framework.logger.AbstractLogEnabled

org.apache.avalon.excalibur.datasource.ids.AbstractIdGenerator

org.apache.avalon.excalibur.datasource.ids.AbstractDataSourceIdGenerator

org.apache.avalon.excalibur.datasource.ids.AbstractDataSourceBlockIdGenerator

All Implemented Interfaces:

IdGenerator, org.apache.avalon.framework.activity.Disposable, org.apache.avalon.framework.activity.Initializable, org.apache.avalon.framework.component.Component, org.apache.avalon.framework.configuration.Configurable, org.apache.avalon.framework.logger.LogEnabled, org.apache.avalon.framework.service.Serviceable, org.apache.avalon.framework.thread.ThreadSafe

Direct Known Subclasses:

TableIdGenerator

public abstract class AbstractDataSourceBlockIdGenerator
extends AbstractDataSourceIdGenerator

The AbstractDataSourceBlockIdGenerator allocates blocks of ids from a DataSource and then provides them as needed. This is useful in reducing communication with the DataSource.

Since:

4.1

Version:

CVS $Revision: 1.4 $ $Date: 2004/02/28 11:47:17 $

Author:

Avalon Development Team

Field Summary

Fields

Modifier and Type	Field and Description
private int	m_allocated The number of ids which have been allocated from the current block.
private int	m_blockSize The number of ids loaded in each block.
private java.math.BigDecimal	m_firstBigDecimal The first id in a batch of Ids loaded in from the DataSource.
private long	m_firstLong The first id in a batch of Ids loaded in from the DataSource.

Fields inherited from class org.apache.avalon.excalibur.datasource.ids.AbstractDataSourceIdGenerator

m_dataSource, m_nextId

Fields inherited from interface org.apache.avalon.excalibur.datasource.ids.IdGenerator

ROLE

Constructor Summary

Constructors

Constructor and Description
AbstractDataSourceBlockIdGenerator()

Method Summary

Methods

Modifier and Type	Method and Description
protected abstract java.math.BigDecimal	allocateBigDecimalIdBlock(int blockSize) Allocates a block, of the given size, of ids from the database.
protected abstract long	allocateLongIdBlock(int blockSize) Allocates a block, of the given size, of ids from the database.
void	configure(org.apache.avalon.framework.configuration.Configuration configuration) Called by the Container to configure the component.
protected java.math.BigDecimal	getNextBigDecimalIdInner() Gets the next id as a Big Decimal.
protected long	getNextLongIdInner() Gets the next id as a long.
void	initialize() Called by the Container to initialize the component.

Methods inherited from class org.apache.avalon.excalibur.datasource.ids.AbstractDataSourceIdGenerator

dispose, getConnection, service

Methods inherited from class org.apache.avalon.excalibur.datasource.ids.AbstractIdGenerator

getNextBigDecimalId, getNextByteId, getNextIntegerId, getNextLongId, getNextLongIdChecked, getNextShortId, isUsingBigDecimals, setUseBigDecimals

Methods inherited from class org.apache.avalon.framework.logger.AbstractLogEnabled

enableLogging, getLogger, setupLogger, setupLogger, setupLogger

Methods inherited from class java.lang.Object

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

Field Detail

m_firstBigDecimal

private java.math.BigDecimal m_firstBigDecimal

The first id in a batch of Ids loaded in from the DataSource.

m_firstLong

private long m_firstLong

The first id in a batch of Ids loaded in from the DataSource.

m_blockSize

private int m_blockSize

The number of ids loaded in each block.

m_allocated

private int m_allocated

The number of ids which have been allocated from the current block.

Constructor Detail

AbstractDataSourceBlockIdGenerator

public AbstractDataSourceBlockIdGenerator()

Method Detail

allocateBigDecimalIdBlock

protected abstract java.math.BigDecimal allocateBigDecimalIdBlock(int blockSize)
                                                           throws IdException

Allocates a block, of the given size, of ids from the database.

Parameters:

blockSize - number of Ids which are to be allocated.

Returns:

The first id in the allocated block.

Throws:

IdException - if there it was not possible to allocate a block of ids.

allocateLongIdBlock

protected abstract long allocateLongIdBlock(int blockSize)
                                     throws IdException

Allocates a block, of the given size, of ids from the database.

Parameters:

blockSize - number of Ids which are to be allocated.

Returns:

The first id in the allocated block.

Throws:

IdException - if there it was not possible to allocate a block of ids.

getNextBigDecimalIdInner

protected java.math.BigDecimal getNextBigDecimalIdInner()
                                                 throws IdException

Gets the next id as a Big Decimal. This method will only be called when synchronized and when the data type is configured to be BigDecimal.

Specified by:

getNextBigDecimalIdInner in class AbstractIdGenerator

Returns:

the next id as a BigDecimal.

Throws:

IdException - if an Id could not be allocated for any reason.

getNextLongIdInner

protected long getNextLongIdInner()
                           throws IdException

Gets the next id as a long. This method will only be called when synchronized and when the data type is configured to be long.

Specified by:

getNextLongIdInner in class AbstractIdGenerator

Returns:

the next id as a long.

Throws:

IdException - if an Id could not be allocated for any reason.

configure

public void configure(org.apache.avalon.framework.configuration.Configuration configuration)
               throws org.apache.avalon.framework.configuration.ConfigurationException

Called by the Container to configure the component.

Specified by:

configure in interface org.apache.avalon.framework.configuration.Configurable

Overrides:

configure in class AbstractDataSourceIdGenerator

Parameters:

configuration - configuration info used to setup the component.

Throws:

org.apache.avalon.framework.configuration.ConfigurationException - if there are any problems with the configuration.

initialize

public void initialize()
                throws java.lang.Exception

Called by the Container to initialize the component.

Specified by:

initialize in interface org.apache.avalon.framework.activity.Initializable

Overrides:

initialize in class AbstractDataSourceIdGenerator

Throws:

java.lang.Exception - if there were any problems durring initialization.