Package org.firebirdsql.gds.ng.jna

Class JnaBlob

    • Constructor Detail

      • JnaBlob

        public JnaBlob​(JnaDatabase database,
               JnaTransaction transaction,
               BlobParameterBuffer blobParameterBuffer)
        Creates a blob for output (writing to the database).
        Parameters:
        database - database
        transaction - transaction
        blobParameterBuffer - blob parameter buffer

      • JnaBlob

        public JnaBlob​(JnaDatabase database,
               JnaTransaction transaction,
               BlobParameterBuffer blobParameterBuffer,
               long blobId)
        Creates a blob for input (reading from the database).
        Parameters:
        database - database
        transaction - transaction
        blobParameterBuffer - blob parameter buffer
        blobId - blob id

    • Method Detail

      • 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 java.sql.SQLException
        Description copied from interface: FbBlob
        Opens an existing input blob, or creates an output blob.
        Specified by:
        open in interface FbBlob
        Throws:
        java.sql.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 java.sql.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:
        java.sql.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 java.sql.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:
        java.sql.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 java.sql.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:
        java.sql.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 java.sql.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:
        java.sql.SQLException

      • closeImpl

        protected void closeImpl()
                  throws java.sql.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:
        java.sql.SQLException

      • cancelImpl

        protected void cancelImpl()
                   throws java.sql.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:
        java.sql.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