Package org.fcrepo.persistence.api

Interface PersistentStorageSession

All Known Implementing Classes:

OcflPersistentStorageSession, OcflPersistentStorageSessionMetrics

public interface PersistentStorageSession

An interface that mediates CRUD operations to and from persistence storage.

Author:

dbernstein, whikloj

Method Summary

Modifier and Type	Method	Description
void	commit()	Commits any changes in the current session to persistent storage.
InputStream	getBinaryContent(FedoraId identifier, Instant version)	Get the persisted binary content for the provided resource.
ResourceHeaders	getHeaders(FedoraId identifier, Instant version)	Get the header information for the identified resource.
String	getId()	Return the ID for this session, or null for a read-only session.
RdfStream	getTriples(FedoraId identifier, Instant version)	Get the client managed triples for the provided resource.
List<Instant>	listVersions(FedoraId identifier)	Returns a list of immutable versions associated with the specified fedora identifier in ascending order by creation time of the version.
void	persist(ResourceOperation operation)	Perform a persistence operation on a resource
void	prepare()	Does anything that's necessary to prepare the session to be committed, for example committing database changes.
void	rollback()	Rolls back any changes in the current session.

Method Detail

getId

String getId()

Return the ID for this session, or null for a read-only session.

Returns:

the session id.

persist

void persist(ResourceOperation operation)
      throws PersistentStorageException

Perform a persistence operation on a resource

Parameters:

operation - The persistence operation to perform

Throws:

PersistentStorageException - Error persisting the resource.

getHeaders

ResourceHeaders getHeaders(FedoraId identifier,
                           Instant version)
                    throws PersistentStorageException

Get the header information for the identified resource.

Parameters:

identifier - identifier of the resource

version - instant identifying the version of the resource to read from. If null, then the head version is used.

Returns:

header information

Throws:

PersistentStorageException - Either a PersistentItemNotFoundException or PersistentSessionClosedException

getTriples

RdfStream getTriples(FedoraId identifier,
                     Instant version)
              throws PersistentStorageException

Get the client managed triples for the provided resource.

Parameters:

identifier - identifier for the resource.

version - instant identifying the version of the resource to read from. If null, then the head version is used.

Returns:

the triples as an RdfStream.

Throws:

PersistentStorageException - Either a PersistentItemNotFoundException or PersistentSessionClosedException

getBinaryContent

InputStream getBinaryContent(FedoraId identifier,
                             Instant version)
                      throws PersistentStorageException

Get the persisted binary content for the provided resource.

Parameters:

identifier - identifier for the resource.

version - instant identifying the version of the resource to read from. If null, then the head version is used.

Returns:

the binary content.

Throws:

PersistentStorageException - Either a PersistentItemNotFoundException or PersistentSessionClosedException

listVersions

List<Instant> listVersions(FedoraId identifier)
                    throws PersistentStorageException

Returns a list of immutable versions associated with the specified fedora identifier in ascending order by creation time of the version.

Parameters:

identifier - identifier for the resource.

Returns:

The list of instants that map to the underlying versions, ordered by time created

Throws:

PersistentStorageException - Either a PersistentItemNotFoundException or PersistentSessionClosedException

prepare

void prepare()
      throws PersistentStorageException

Does anything that's necessary to prepare the session to be committed, for example committing database changes. This method MUST be called before commit(). If prepare() fails, then the session should be rolled back.

Throws:

PersistentStorageException - if an error is encountered

commit

void commit()
     throws PersistentStorageException

Commits any changes in the current session to persistent storage.

Throws:

PersistentStorageException - Error during commit.

rollback

void rollback()
       throws PersistentStorageException

Rolls back any changes in the current session.

Throws:

PersistentStorageException - Error completing rollback.