er.extensions.migration

Class ERXJDBCMigrationLock

java.lang.Object

er.extensions.migration.ERXJDBCMigrationLock

All Implemented Interfaces:

IERXMigrationLock

public class ERXJDBCMigrationLock
extends Object
implements IERXMigrationLock

JDBC implementation of the migration lock.

Author:

mschrag

Properties

Name	Description
er.migration.JDBC.dbUpdaterTableName	the name of the db update version table (defaults to _DBUpdater)
er.migration.createTablesIfNecessary	if true, the tables and model rows will be created automatically. *ONLY SET THIS IF YOU ARE RUNNING IN DEVELOPMENT MODE OR WITH A SINGLE INSTANCE*. If you are running multiple instances, the instances will not be able to acquire locks properly and you may end up with multiple instances attempting to create lock tables and/or failing to startup properly.
<ModelName>.InitialMigrationVersion	the starting version number (in case you are retrofitting a project with migrations)

Constructor Summary

Constructors

Constructor and Description
ERXJDBCMigrationLock()

Method Summary

Modifier and Type	Method and Description
boolean	_tryLock(com.webobjects.eoaccess.EOAdaptorChannel channel, com.webobjects.eoaccess.EOModel model, String lockOwnerName, boolean createTableIfMissing)
protected boolean	createIfMissing()
protected String	dbUpdaterCreateStatement(com.webobjects.eoaccess.EOModel model, com.webobjects.jdbcadaptor.JDBCAdaptor adaptor)
protected com.webobjects.eoaccess.EOModel	dbUpdaterModelWithModel(com.webobjects.eoaccess.EOModel model, com.webobjects.jdbcadaptor.JDBCAdaptor adaptor)
protected int	initialVersionForModel(com.webobjects.eoaccess.EOModel model)
protected String	migrationTableName(com.webobjects.jdbcadaptor.JDBCAdaptor adaptor) Adds support for overriding the name of the db updater table on a per-database product level.
void	setVersionNumber(com.webobjects.eoaccess.EOAdaptorChannel channel, com.webobjects.eoaccess.EOModel model, int versionNumber) Sets the current version number of the named model.
boolean	tryLock(com.webobjects.eoaccess.EOAdaptorChannel channel, com.webobjects.eoaccess.EOModel model, String lockOwnerName) Attempts to retrieve a lock on the migration process for the named model.
void	unlock(com.webobjects.eoaccess.EOAdaptorChannel channel, com.webobjects.eoaccess.EOModel model) Unlocks the given model.
int	versionNumber(com.webobjects.eoaccess.EOAdaptorChannel channel, com.webobjects.eoaccess.EOModel model) Returns the current version number of the named model.

Methods inherited from class java.lang.Object

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

Constructor Detail

ERXJDBCMigrationLock

public ERXJDBCMigrationLock()

Method Detail

migrationTableName

protected String migrationTableName(com.webobjects.jdbcadaptor.JDBCAdaptor adaptor)

Adds support for overriding the name of the db updater table on a per-database product level.

Parameters:

adaptor - the current jdbc adaptor

Returns:

the name of the dbupdater table

createIfMissing

protected boolean createIfMissing()

tryLock

public boolean tryLock(com.webobjects.eoaccess.EOAdaptorChannel channel,
                       com.webobjects.eoaccess.EOModel model,
                       String lockOwnerName)

Description copied from interface: IERXMigrationLock

Attempts to retrieve a lock on the migration process for the named model. A lockOwnerName is provided that provides a simple mechanism to recover from a stale lock. If the lock owner name passed in matches the current lock owner name, then the lock is acquired.

Specified by:

tryLock in interface IERXMigrationLock

Parameters:

channel - the adaptor channel associated with this process

model - the model to try to lock

lockOwnerName - the name of the lock owner

Returns:

true if the lock was acquired, false if it was not

_tryLock

public boolean _tryLock(com.webobjects.eoaccess.EOAdaptorChannel channel,
                        com.webobjects.eoaccess.EOModel model,
                        String lockOwnerName,
                        boolean createTableIfMissing)

unlock

public void unlock(com.webobjects.eoaccess.EOAdaptorChannel channel,
                   com.webobjects.eoaccess.EOModel model)

Description copied from interface: IERXMigrationLock

Unlocks the given model. This should only be called if you acquired a lock with tryLock(..).

Specified by:

unlock in interface IERXMigrationLock

Parameters:

channel - the adaptor channel associated with this process

model - the model to unlock

versionNumber

public int versionNumber(com.webobjects.eoaccess.EOAdaptorChannel channel,
                         com.webobjects.eoaccess.EOModel model)

Description copied from interface: IERXMigrationLock

Returns the current version number of the named model.

Specified by:

versionNumber in interface IERXMigrationLock

Parameters:

channel - the adaptor channel associated with this process

model - the model to lookup version information on

Returns:

the current version number of the named model

setVersionNumber

public void setVersionNumber(com.webobjects.eoaccess.EOAdaptorChannel channel,
                             com.webobjects.eoaccess.EOModel model,
                             int versionNumber)

Description copied from interface: IERXMigrationLock

Sets the current version number of the named model.

Specified by:

setVersionNumber in interface IERXMigrationLock

Parameters:

channel - the adaptor channel associated with this process

model - the model to set version information on

versionNumber - the new version number

initialVersionForModel

protected int initialVersionForModel(com.webobjects.eoaccess.EOModel model)

dbUpdaterModelWithModel

protected com.webobjects.eoaccess.EOModel dbUpdaterModelWithModel(com.webobjects.eoaccess.EOModel model,
                                                                  com.webobjects.jdbcadaptor.JDBCAdaptor adaptor)

dbUpdaterCreateStatement

protected String dbUpdaterCreateStatement(com.webobjects.eoaccess.EOModel model,
                                          com.webobjects.jdbcadaptor.JDBCAdaptor adaptor)