Package org.firebirdsql.gds.ng.jna

Class JnaBlob

java.lang.Object
org.firebirdsql.gds.ng.AbstractFbBlob
org.firebirdsql.gds.ng.jna.JnaBlob
All Implemented Interfaces:
AutoCloseable, FbBlob, DatabaseListener, ExceptionListenable, TransactionListener
public class JnaBlob extends AbstractFbBlob implements FbBlob, DatabaseListener
Implementation of FbBlob for native client access.
Since:
3.0
Author:
Mark Rotteveel

  • Constructor Details

  • Method Details

    • getDatabase

      public JnaDatabase getDatabase()
      Specified by:
      getDatabase in interface FbBlob
      Overrides:
      getDatabase in class AbstractFbBlob
      Returns:
      The database connection that created this blob

    • getTransaction

      public JnaTransaction getTransaction()
      Overrides:
      getTransaction in class AbstractFbBlob

    • getHandle

      public int getHandle()
      Specified by:
      getHandle in interface FbBlob
      Returns:
      The Firebird blob handle identifier

    • getJnaHandle

      public final com.sun.jna.ptr.IntByReference getJnaHandle()

    • getBlobId

      public final long getBlobId()
      Specified by:
      getBlobId in interface FbBlob
      Returns:
      The Firebird blob id

    • open

      public void open() throws SQLException
      Description copied from interface: FbBlob
      Opens an existing input blob, or creates an output blob.
      Specified by:
      open in interface FbBlob
      Throws:
      SQLException - If the blob is already open, this is a (closed) output blob and it already has a blobId, the transaction is not active, or a database connection error occurred

    • isOutput

      public final boolean isOutput()
      Specified by:
      isOutput in interface FbBlob
      Returns:
      true if this is an output blob (write only), false if this is an input blob (read only)

    • getSegment

      public byte[] getSegment(int sizeRequested) throws SQLException
      Description copied from interface: FbBlob
      Gets a segment of blob data.

      When sizeRequested exceeds FbBlob.getMaximumSegmentSize() it is silently reduced to the maximum segment size.

      TODO: Consider allowing this and have the implementation handle longer segments by sending multiple (batched?) requests.
      Specified by:
      getSegment in interface FbBlob
      Parameters:
      sizeRequested - Requested segment size (> 0).
      Returns:
      Retrieved segment (size may be less than requested)
      Throws:
      SQLException - If this is an output blob, the blob is closed, the transaction is not active, or a database connection error occurred.

    • putSegment

      public void putSegment(byte[] segment) throws SQLException
      Description copied from interface: FbBlob
      Writes a segment of blob data.

      Implementation must handle segment length exceeding FbBlob.getMaximumSegmentSize() by batching. TODO: reconsider and let caller handle that?

      Passing a section that is length 0 will throw an SQLException.

      Specified by:
      putSegment in interface FbBlob
      Parameters:
      segment - Segment to write
      Throws:
      SQLException - If this is an input blob, the blob is closed, the transaction is not active, the segment is length 0 or longer than the maximum segment size, or a database connection error occurred.

    • seek

      public void seek(int offset, FbBlob.SeekMode seekMode) throws SQLException
      Description copied from interface: FbBlob
      Performs a seek on a blob with the specified seekMode and offset.

      Firebird only supports seek on stream blobs.

      Specified by:
      seek in interface FbBlob
      Parameters:
      offset - Offset of the seek, effect depends on value of seekMode
      seekMode - Value of FbBlob.SeekMode
      Throws:
      SQLException - If the blob is closed, the transaction is not active, or a database error occurred.

    • getBlobInfo

      public byte[] getBlobInfo(byte[] requestItems, int bufferLength) throws SQLException
      Description copied from interface: FbBlob
      Request blob info.
      Specified by:
      getBlobInfo in interface FbBlob
      Parameters:
      requestItems - Array of info items to request
      bufferLength - Response buffer length to use
      Returns:
      Response buffer
      Throws:
      SQLException

    • closeImpl

      protected void closeImpl() throws SQLException
      Description copied from class: AbstractFbBlob
      Internal implementation of AbstractFbBlob.close(). The implementation does not need to check for attached database and active transaction, nor does it need to mark this blob as closed.
      Specified by:
      closeImpl in class AbstractFbBlob
      Throws:
      SQLException

    • cancelImpl

      protected void cancelImpl() throws SQLException
      Description copied from class: AbstractFbBlob
      Internal implementation of AbstractFbBlob.cancel(). The implementation does not need to check for attached database and active transaction, nor does it need to mark this blob as closed.
      Specified by:
      cancelImpl in class AbstractFbBlob
      Throws:
      SQLException

    • releaseResources

      protected void releaseResources()
      Description copied from class: AbstractFbBlob
      Release Java resources held. This should not communicate with the Firebird server.
      Specified by:
      releaseResources in class AbstractFbBlob