Package org.dspace.storage.bitstore.service

Interface BitstreamStorageService

All Known Implementing Classes:
BitstreamStorageServiceImpl
public interface BitstreamStorageService

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

  • Method Details

    • store

      UUID store(Context context, Bitstream bitstream, 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
      bitstream - The bitstream to store
      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

      UUID register(Context context, Bitstream bitstream, int assetstore, String bitstreamPath) throws SQLException, IOException, AuthorizeException
      Register a bitstream already in storage.
      Parameters:
      context - The current context
      bitstream - The bitstream to register
      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 this assetstore.
      Returns:
      The ID of the registered bitstream
      Throws:
      SQLException - If a problem occurs accessing the RDBMS
      IOException - if IO error
      AuthorizeException - Exception indicating the current user of the context does not have permission to perform a particular action.

    • computeChecksum

      Map<String,Object> computeChecksum(Context context, Bitstream bitstream) throws IOException
      Throws:
      IOException

    • isRegisteredBitstream

      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

      InputStream retrieve(Context context, Bitstream bitstream) 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
      bitstream - 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

    • cleanup

      void cleanup(boolean deleteDbRecords, boolean verbose) throws SQLException, IOException, AuthorizeException
      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
      verbose - verbosity flag
      Throws:
      IOException - If a problem occurs while cleaning up
      SQLException - If a problem occurs accessing the RDBMS
      AuthorizeException - Exception indicating the current user of the context does not have permission to perform a particular action.

    • clone

      Bitstream clone(Context context, Bitstream bitstream) throws SQLException, IOException, AuthorizeException
      Clone the given bitstream to a new bitstream with a new ID. Metadata of the given bitstream are also copied to the new bitstream.
      Parameters:
      context - DSpace context object
      bitstream - the bitstream to be cloned
      Returns:
      id of the clone bitstream.
      Throws:
      SQLException - if database error
      IOException - if IO error
      AuthorizeException - if authorization error

    • printStores

      void printStores(Context context) throws SQLException
      Print out (log/out) a listing of the assetstores configured, and how many assets they contain
      Parameters:
      context - The relevant DSpace Context.
      Throws:
      SQLException - if database error

    • migrate

      void migrate(Context context, Integer assetstoreSource, Integer assetstoreDestination, boolean deleteOld, Integer batchCommitSize) throws IOException, SQLException, AuthorizeException
      Migrate all the assets from assetstoreSource to assetstoreDestination
      Parameters:
      context - The relevant DSpace Context.
      assetstoreSource - source assetstore
      assetstoreDestination - destination assetstore
      deleteOld - whether to delete files from the source assetstore after migration
      batchCommitSize - batch size
      Throws:
      IOException - A general class of exceptions produced by failed or interrupted I/O operations.
      SQLException - An exception that provides information on a database access error or other errors.
      AuthorizeException - Exception indicating the current user of the context does not have permission to perform a particular action.

    • getLastModified

      @Nullable Long getLastModified(Bitstream bitstream) throws IOException
      Gets the last modified timestamp of the the given bitstream's content, if known.
      Parameters:
      bitstream - the bitstream.
      Returns:
      the timestamp in milliseconds, or null if unknown.
      Throws:
      IOException - if an unexpected io error occurs.

    • setIncomingExternal

      void setIncomingExternal(int incoming)
      Sets the number for the incoming store
      Parameters:
      incoming -