Package io.deephaven.persistence

Interface Persistence.Callbacks<UpdateType>

All Known Implementing Classes:

PersistentHashtable

Enclosing interface:

Persistence<UpdateType>

public static interface Persistence.Callbacks<UpdateType>

Represents the Persistence instance's communication with the in-memory state of the collection.

Method Summary

Modifier and Type	Method	Description
List<UpdateType>	getCheckPoint()	Called to obtain an atomic (?) snapshot of the contents of the persistent collection in preparation for writing a checkpoint.
void	handlePersistenceInitializationUpdate(Object obj)	Handle an update read from the persistent cache while the persistent collection is being initialized.
void	releaseCheckPoint(List<UpdateType> checkpoint)	Called once for every call to getCheckPoint(), to indicate that the persistence implementation is finished with the checkpoint list and the objects contained within it.

Method Details

handlePersistenceInitializationUpdate

void handlePersistenceInitializationUpdate(Object obj)

Handle an update read from the persistent cache while the persistent collection is being initialized. This should be called *only* during initPersistence().

Parameters:

obj - The object just read from the persistent stream.

getCheckPoint

List<UpdateType> getCheckPoint()

Called to obtain an atomic (?) snapshot of the contents of the persistent collection in preparation for writing a checkpoint. The persistence policy that the PersistenceImpl was instantiated with controls when checkpoints are written, so this call may come at any time.

Returns:

the list of UpdateType objects (commands) representing the current state of the collection

releaseCheckPoint

void releaseCheckPoint(List<UpdateType> checkpoint)

Called once for every call to getCheckPoint(), to indicate that the persistence implementation is finished with the checkpoint list and the objects contained within it.

Parameters:

checkpoint - the checkpoint from the getCheckPoint() call