org.fcrepo.server.storage.lowlevel

Class DefaultLowlevelStorage

java.lang.Object

org.fcrepo.server.storage.lowlevel.DefaultLowlevelStorage

All Implemented Interfaces:

ICheckable, IListable, ILowlevelStorage, ISizable

public class DefaultLowlevelStorage
extends Object
implements ILowlevelStorage, IListable, ISizable, ICheckable

Author:

Bill Niebel

Field Summary

Fields

Modifier and Type	Field and Description
static String	DATASTREAM_REGISTRY_TABLE
static String	DATASTREAM_STORE_BASE
static String	FILESYSTEM
static String	OBJECT_REGISTRY_TABLE
static String	OBJECT_STORE_BASE
static String	PATH_ALGORITHM
static String	PATH_REGISTRY
static String	REGISTRY_NAME

Constructor Summary

Constructors

Constructor and Description
DefaultLowlevelStorage(Map<String,Object> configuration)

Method Summary

Methods

Modifier and Type	Method and Description
long	addDatastream(String pid, InputStream content, Map<String,String> hints) Sets the content of a new datastream version.
void	addObject(String pid, InputStream content, Map<String,String> hints) Adds a new object.
void	auditDatastream() Performs a consistency check against the datastream index if such an index exists.
void	auditObject() Performs a consistency check against the object index if such an index exists.
long	getDatastreamSize(String dsKey) Return the size of a datastream in bytes
Iterator<String>	listDatastreams() Lists all stored datastreams in no particular order.
Iterator<String>	listObjects() Lists all stored objects in no particular order.
boolean	objectExists(String objectKey)
void	rebuildDatastream() Reconstructs the datastream index if such an index exists.
void	rebuildObject() Reconstructs the object index if such an index exists.
void	removeDatastream(String pid) Removes the content of an existing datastream version.
void	removeObject(String pid) Removes an object.
long	replaceDatastream(String pid, InputStream content, Map<String,String> hints) Sets the content of an existing datastream version.
void	replaceObject(String pid, InputStream content, Map<String,String> hints) Replaces an existing object.
InputStream	retrieveDatastream(String pid) Gets the content of an existing datastream version.
InputStream	retrieveObject(String pid) Gets an existing object.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

REGISTRY_NAME

public static final String REGISTRY_NAME

See Also:

Constant Field Values

OBJECT_REGISTRY_TABLE

public static final String OBJECT_REGISTRY_TABLE

See Also:

Constant Field Values

DATASTREAM_REGISTRY_TABLE

public static final String DATASTREAM_REGISTRY_TABLE

See Also:

Constant Field Values

OBJECT_STORE_BASE

public static final String OBJECT_STORE_BASE

See Also:

Constant Field Values

DATASTREAM_STORE_BASE

public static final String DATASTREAM_STORE_BASE

See Also:

Constant Field Values

FILESYSTEM

public static final String FILESYSTEM

See Also:

Constant Field Values

PATH_ALGORITHM

public static final String PATH_ALGORITHM

See Also:

Constant Field Values

PATH_REGISTRY

public static final String PATH_REGISTRY

See Also:

Constant Field Values

Constructor Detail

DefaultLowlevelStorage

public DefaultLowlevelStorage(Map<String,Object> configuration)
                       throws LowlevelStorageException

Throws:

LowlevelStorageException

Method Detail

addObject

public void addObject(String pid,
             InputStream content,
             Map<String,String> hints)
               throws LowlevelStorageException

Description copied from interface: ILowlevelStorage

Adds a new object.

Specified by:

addObject in interface ILowlevelStorage

Parameters:

pid - the pid of the object.

content - the serialized object.

hints - a map of hints for object storage

Throws:

LowlevelStorageException - if the object already exists or cannot be added for any other reason.

replaceObject

public void replaceObject(String pid,
                 InputStream content,
                 Map<String,String> hints)
                   throws LowlevelStorageException

Description copied from interface: ILowlevelStorage

Replaces an existing object.

Specified by:

replaceObject in interface ILowlevelStorage

Parameters:

pid - the pid of the object.

content - the serialized object.

Throws:

LowlevelStorageException - if the object does not already exist or cannot be replaced for any other reason.

retrieveObject

public InputStream retrieveObject(String pid)
                           throws LowlevelStorageException

Description copied from interface: ILowlevelStorage

Gets an existing object.

Specified by:

retrieveObject in interface ILowlevelStorage

Parameters:

pid - the pid of the object.

Returns:

the serialized form of the object, as stored.

Throws:

LowlevelStorageException - if the object does not exist or cannot be read for any other reason.

removeObject

public void removeObject(String pid)
                  throws LowlevelStorageException

Description copied from interface: ILowlevelStorage

Removes an object.

Specified by:

removeObject in interface ILowlevelStorage

Parameters:

pid - the pid of the object.

Throws:

LowlevelStorageException - if the object does not exist or cannot be removed for any other reason.

rebuildObject

public void rebuildObject()
                   throws LowlevelStorageException

Description copied from interface: ILowlevelStorage

Reconstructs the object index if such an index exists. The object index associates an object with a stored location. If the implementation does not use an index, this is a no-op.

Warning

Rebuilding the object index is not expected to be an atomic operation and should only be run while the system is offline or reads and writes are otherwise prevented.

Specified by:

rebuildObject in interface ILowlevelStorage

Throws:

LowlevelStorageException - if an error occurs that prevents the index from being rebuilt.

auditObject

public void auditObject()
                 throws LowlevelStorageException

Description copied from interface: ILowlevelStorage

Performs a consistency check against the object index if such an index exists. The object index associates an object with a stored location. If the implementation does not use an index, this is a no-op. If any inconsistencies are found, they will be reported to the system logger.

Specified by:

auditObject in interface ILowlevelStorage

Throws:

LowlevelStorageException - if an error occurs that prevents the consistency check from taking place.

addDatastream

public long addDatastream(String pid,
                 InputStream content,
                 Map<String,String> hints)
                   throws LowlevelStorageException

Description copied from interface: ILowlevelStorage

Sets the content of a new datastream version.

Specified by:

addDatastream in interface ILowlevelStorage

Parameters:

pid - the $pid "+" $dsId "+" $dsVersionId string that uniquely identifies the datastream version.

content - the content.

Throws:

LowlevelStorageException - if the datastream version already exists or cannot be added for any other reason.

replaceDatastream

public long replaceDatastream(String pid,
                     InputStream content,
                     Map<String,String> hints)
                       throws LowlevelStorageException

Description copied from interface: ILowlevelStorage

Sets the content of an existing datastream version.

Specified by:

replaceDatastream in interface ILowlevelStorage

Parameters:

pid - the $pid "+" $dsId "+" $dsVersionId string that uniquely identifies the datastream version.

content - the content.

Throws:

LowlevelStorageException - if the datastream version does not already exist or cannot be replaced for any other reason.

retrieveDatastream

public InputStream retrieveDatastream(String pid)
                               throws LowlevelStorageException

Description copied from interface: ILowlevelStorage

Gets the content of an existing datastream version.

Specified by:

retrieveDatastream in interface ILowlevelStorage

Parameters:

pid - the $pid "+" $dsId "+" $dsVersionId string that uniquely identifies the datastream version.

Returns:

the content.

Throws:

LowlevelStorageException - if the datastream version does not exist or cannot be read for any other reason.

removeDatastream

public void removeDatastream(String pid)
                      throws LowlevelStorageException

Description copied from interface: ILowlevelStorage

Removes the content of an existing datastream version.

Specified by:

removeDatastream in interface ILowlevelStorage

Parameters:

pid - the $pid "+" $dsId "+" $dsVersionId string that uniquely identifies the datastream version.

Throws:

LowlevelStorageException - if the datastream version does not exist or cannot be removed for any other reason.

rebuildDatastream

public void rebuildDatastream()
                       throws LowlevelStorageException

Description copied from interface: ILowlevelStorage

Reconstructs the datastream index if such an index exists. The datastream index associates a datastream version with a stored location. If the implementation does not use an index, this is a no-op.

Warning

Rebuilding the datastream index is not expected to be an atomic operation and should only be run while the system is offline or reads and writes are otherwise prevented.

Specified by:

rebuildDatastream in interface ILowlevelStorage

Throws:

LowlevelStorageException - if an error occurs that prevents the

auditDatastream

public void auditDatastream()
                     throws LowlevelStorageException

Description copied from interface: ILowlevelStorage

Performs a consistency check against the datastream index if such an index exists. The datastream index associates a datastream version with a stored location. If the implementation does not use an index, this is a no-op. If any inconsistencies are found, they will be reported to the system logger.

Specified by:

auditDatastream in interface ILowlevelStorage

Throws:

LowlevelStorageException - if an error occurs that prevents the consistency check from taking place.

listObjects

public Iterator<String> listObjects()

Description copied from interface: IListable

Lists all stored objects in no particular order.

Specified by:

listObjects in interface IListable

Returns:

an iterator of all stored object pids.

listDatastreams

public Iterator<String> listDatastreams()

Description copied from interface: IListable

Lists all stored datastreams in no particular order.

Specified by:

listDatastreams in interface IListable

Returns:

an iterator of all stored datastream keys, each in the following format: $pid "+" $dsId "+" $dsVersionId

getDatastreamSize

public long getDatastreamSize(String dsKey)
                       throws LowlevelStorageException

Description copied from interface: ISizable

Return the size of a datastream in bytes

Specified by:

getDatastreamSize in interface ISizable

Returns:

Throws:

LowlevelStorageException

objectExists

public boolean objectExists(String objectKey)

Specified by:

objectExists in interface ICheckable