er.extensions.migration
Interface IERXMigrationLock

All Known Implementing Classes:

ERXJDBCMigrationLock

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(EOAdaptorChannel channel, EOModel model, int versionNumber) Sets the current version number of the named model.
boolean	tryLock(EOAdaptorChannel channel, EOModel model, String lockOwnerName) Attempts to retrieve a lock on the migration process for the named model.
void	unlock(EOAdaptorChannel channel, EOModel model) Unlocks the given model.
int	versionNumber(EOAdaptorChannel channel, EOModel model) Returns the current version number of the named model.

Method Detail

versionNumber

int versionNumber(EOAdaptorChannel channel,
                  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(EOAdaptorChannel channel,
                      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(EOAdaptorChannel channel,
                EOModel model,
                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(EOAdaptorChannel channel,
            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