er.extensions.migration
Interface IERXMigrationLock

All Known Implementing Classes:

ERXJDBCMigrationLock, ERXMemoryMigrationLock

public interface IERXMigrationLock

Because you might be running with multiple instances, there needs to be a locking mechanism that is higher level than just a db context lock. IERXMigrationLock is a simple interface for accessing and locking information about the migration process.

Author:

mschrag

Method Summary

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, java.lang.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.

Method Detail

versionNumber

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

Returns the current version number of the named model.

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

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

Sets the current version number of the named model.

Parameters:

channel - the adaptor channel associated with this process

model - the model to set version information on

versionNumber - the new version number

tryLock

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

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.

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

unlock

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

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

Parameters:

channel - the adaptor channel associated with this process

model - the model to unlock