org.dspace.storage.bitstore

Class BitstreamStorageManager

java.lang.Object

org.dspace.storage.bitstore.BitstreamStorageManager

public class BitstreamStorageManager
extends Object

Stores, retrieves and deletes bitstreams.

Presently, asset stores are specified in dspace.cfg. Since Java does not offer a way of detecting free disk space, the asset store to use for new bitstreams is also specified in a configuration property. The drawbacks to this are that the administrators are responsible for monitoring available space in the asset stores, and DSpace (Tomcat) has to be restarted when the asset store for new ('incoming') bitstreams is changed.

Mods by David Little, UCSD Libraries 12/21/04 to allow the registration of files (bitstreams) into DSpace.

Cleanup integration with checker package by Nate Sarr 2006-01. N.B. The dependency on the checker package isn't ideal - a Listener pattern would be better but was considered overkill for the purposes of integrating the checker. It would be worth re-considering a Listener pattern if another package needs to be notified of BitstreamStorageManager actions.

Version:

$Revision$

Author:

Peter Breton, Robert Tansley, David Little, Nathan Sarr

Constructor Summary

Constructors

Constructor and Description
BitstreamStorageManager()

Method Summary

Methods

Modifier and Type	Method and Description
static void	cleanup(boolean deleteDbRecords, boolean verbose) Clean up the bitstream storage area.
static int	clone(Context context, int id)
static void	delete(Context context, int id) Remove a bitstream from the asset store.
static boolean	isRegisteredBitstream(String internalId) Does the internal_id column in the bitstream row indicate the bitstream is a registered file
static int	register(Context context, int assetstore, String bitstreamPath) Register a bitstream already in storage.
static InputStream	retrieve(Context context, int id) Retrieve the bits for the bitstream with ID.
static int	store(Context context, InputStream is) Store a stream of bits.

Methods inherited from class java.lang.Object

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

Constructor Detail

BitstreamStorageManager

public BitstreamStorageManager()

Method Detail

store

public static int store(Context context,
        InputStream is)
                 throws SQLException,
                        IOException

Store a stream of bits.

If this method returns successfully, the bits have been stored, and RDBMS metadata entries are in place (the context still needs to be completed to finalize the transaction).

If this method returns successfully and the context is aborted, then the bits will be stored in the asset store and the RDBMS metadata entries will exist, but with the deleted flag set.

If this method throws an exception, then any of the following may be true:

• Neither bits nor RDBMS metadata entries have been stored.
• RDBMS metadata entries with the deleted flag set have been stored, but no bits.
• RDBMS metadata entries with the deleted flag set have been stored, and some or all of the bits have also been stored.

Parameters:

context - The current context

is - The stream of bits to store

Returns:

The ID of the stored bitstream

Throws:

IOException - If a problem occurs while storing the bits

SQLException - If a problem occurs accessing the RDBMS

register

public static int register(Context context,
           int assetstore,
           String bitstreamPath)
                    throws SQLException,
                           IOException

Register a bitstream already in storage.

Parameters:

context - The current context

assetstore - The assetstore number for the bitstream to be registered

bitstreamPath - The relative path of the bitstream to be registered. The path is relative to the path of ths assetstore.

Returns:

The ID of the registered bitstream

Throws:

SQLException - If a problem occurs accessing the RDBMS

IOException

isRegisteredBitstream

public static boolean isRegisteredBitstream(String internalId)

Does the internal_id column in the bitstream row indicate the bitstream is a registered file

Parameters:

internalId - the value of the internal_id column

Returns:

true if the bitstream is a registered file

retrieve

public static InputStream retrieve(Context context,
                   int id)
                            throws SQLException,
                                   IOException

Retrieve the bits for the bitstream with ID. If the bitstream does not exist, or is marked deleted, returns null.

Parameters:

context - The current context

id - The ID of the bitstream to retrieve

Returns:

The stream of bits, or null

Throws:

IOException - If a problem occurs while retrieving the bits

SQLException - If a problem occurs accessing the RDBMS

delete

public static void delete(Context context,
          int id)
                   throws SQLException

Remove a bitstream from the asset store. This method does not delete any bits, but simply marks the bitstreams as deleted (the context still needs to be completed to finalize the transaction).

If the context is aborted, the bitstreams deletion status remains unchanged.

Parameters:

context - The current context

id - The ID of the bitstream to delete

Throws:

SQLException - If a problem occurs accessing the RDBMS

cleanup

public static void cleanup(boolean deleteDbRecords,
           boolean verbose)
                    throws SQLException,
                           IOException

Clean up the bitstream storage area. This method deletes any bitstreams which are more than 1 hour old and marked deleted. The deletions cannot be undone.

Parameters:

deleteDbRecords - if true deletes the database records otherwise it only deletes the files and directories in the assetstore

Throws:

IOException - If a problem occurs while cleaning up

SQLException - If a problem occurs accessing the RDBMS

clone

public static int clone(Context context,
        int id)
                 throws SQLException

Parameters:

context -

id - of the bitstream to clone.

Returns:

id of the clone bitstream.

Throws:

SQLException