org.datanucleus.store

Interface StorePersistenceHandler

All Known Implementing Classes:

AbstractPersistenceHandler, FederatedPersistenceHandler

public interface StorePersistenceHandler

Interface defining persistence operations of a StoreManager. This performs the low level communication with the actual datastore. To be implemented by all new datastore support. Please use AbstractPersistenceHandler and extend it. All PersistenceHandlers should have a single constructor with signature

 public MyPersistenceHandler(StoreManager storeMgr)
 {
 }
 

Method Summary

Modifier and Type	Method and Description
void	batchEnd(ExecutionContext ec, PersistenceBatchType type) Signal that the current batch of operations are ending for the specified ExecutionContext.
void	batchStart(ExecutionContext ec, PersistenceBatchType batchType) Signal that a batch of operations are starting for the specified ExecutionContext.
void	close() Method to close the persistence handler, and release any resources.
void	deleteObject(ObjectProvider op) Deletes a persistent object from the datastore.
void	deleteObjects(ObjectProvider... ops) Method to delete an array of objects from the datastore.
void	fetchObject(ObjectProvider op, int[] fieldNumbers) Fetches a persistent object from the database.
Object	findObject(ExecutionContext ec, Object id) Method to find a persistable object with the specified id from the datastore, if the StoreManager supports this operation (optional).
Object[]	findObjects(ExecutionContext ec, Object[] ids) Method to find an array of objects with the specified identities from the datastore.
void	insertObject(ObjectProvider op) Inserts a persistent object into the database.
void	insertObjects(ObjectProvider... ops) Method to insert an array of objects to the datastore.
void	locateObject(ObjectProvider op) Locates this object in the datastore.
void	locateObjects(ObjectProvider[] ops) Locates object(s) in the datastore.
void	updateObject(ObjectProvider op, int[] fieldNumbers) Updates a persistent object in the datastore.

Method Detail

close

void close()

Method to close the persistence handler, and release any resources.

batchStart

void batchStart(ExecutionContext ec,
                PersistenceBatchType batchType)

Signal that a batch of operations are starting for the specified ExecutionContext. The batch type allows the store plugin to create whatever type of batch it needs.

Parameters:

ec - The ExecutionContext

batchType - Type of this batch that is starting

batchEnd

void batchEnd(ExecutionContext ec,
              PersistenceBatchType type)

Signal that the current batch of operations are ending for the specified ExecutionContext.

Parameters:

ec - The ExecutionContext

type - Type of batch that is ending

insertObject

void insertObject(ObjectProvider op)

Inserts a persistent object into the database.

Parameters:

op - The ObjectProvider of the object to be inserted.

Throws:

NucleusDataStoreException - when an error occurs in the datastore communication

insertObjects

void insertObjects(ObjectProvider... ops)

Method to insert an array of objects to the datastore.

Parameters:

ops - ObjectProviders for the objects to insert

updateObject

void updateObject(ObjectProvider op,
                  int[] fieldNumbers)

Updates a persistent object in the datastore.

Parameters:

op - The ObjectProvider of the object to be updated.

fieldNumbers - The numbers of the fields to be updated.

Throws:

NucleusDataStoreException - when an error occurs in the datastore communication

deleteObject

void deleteObject(ObjectProvider op)

Deletes a persistent object from the datastore.

Parameters:

op - The ObjectProvider of the object to be deleted.

Throws:

NucleusDataStoreException - when an error occurs in the datastore communication

deleteObjects

void deleteObjects(ObjectProvider... ops)

Method to delete an array of objects from the datastore.

Parameters:

ops - ObjectProviders for the objects to delete

fetchObject

void fetchObject(ObjectProvider op,
                 int[] fieldNumbers)

Fetches a persistent object from the database.

Parameters:

op - The ObjectProvider of the object to be fetched.

fieldNumbers - The numbers of the fields to be fetched.

Throws:

NucleusObjectNotFoundException - if the object doesn't exist

NucleusDataStoreException - when an error occurs in the datastore communication

locateObject

void locateObject(ObjectProvider op)

Locates this object in the datastore.

Parameters:

op - The ObjectProvider for the object to be found

Throws:

NucleusObjectNotFoundException - if the object doesn't exist

NucleusDataStoreException - when an error occurs in the datastore communication

locateObjects

void locateObjects(ObjectProvider[] ops)

Locates object(s) in the datastore.

Parameters:

ops - ObjectProvider(s) for the object(s) to be found

Throws:

NucleusObjectNotFoundException - if an object doesn't exist

NucleusDataStoreException - when an error occurs in the datastore communication

findObject

Object findObject(ExecutionContext ec,
                  Object id)

Method to find a persistable object with the specified id from the datastore, if the StoreManager supports this operation (optional). This allows for datastores that perform the instantiation of objects directly (such as ODBMS). With other types of datastores (e.g RDBMS) this method returns null.

Parameters:

ec - The ExecutionContext

id - the id of the object in question.

Returns:

a persistable object with a valid object state (for example: hollow) or null, indicating that the implementation leaves the instantiation work to DataNucleus.

Throws:

NucleusObjectNotFoundException - if this route is supported yet the object doesn't exist

NucleusDataStoreException - when an error occurs in the datastore communication

findObjects

Object[] findObjects(ExecutionContext ec,
                     Object[] ids)

Method to find an array of objects with the specified identities from the datastore. This allows for datastores that perform the instantiation of objects directly (such as ODBMS). With other types of datastores (e.g RDBMS) this method returns null.

Parameters:

ec - The ExecutionContext

ids - identities of the object(s) to retrieve

Returns:

The persistable objects with these identities (in the same order as

ids

)

Throws:

NucleusObjectNotFoundException - if an object doesn't exist

NucleusDataStoreException - when an error occurs in the datastore communication