package org.jscsi.target.scsi.sense.senseDataDescriptor;

 import java.nio.ByteBuffer;

 import org.jscsi.target.scsi.sense.information.EightByteInformation;

 import org.jscsi.target.util.BitManip;

 /**

  * The information sense data descriptor provides information that is device-type or command specific and is defined in

  * a command standard.

  * 

  * @author Andreas Ergenzinger

  */

 public final class InformationSenseDataDescriptor extends SenseDataDescriptor {

     /**

      * The position of the byte containing the VALID bit.

      */

     private static final int VALID_FLAG_BYTE_INDEX = 2;

     /**

      * The position of the INFORMATION field.

      */

     private static final int INFORMATION_INDEX = 4;

     /**

      * The VALID bit shall be set to one.

      * <p>

      * In previous versions of this standard and in the fixed format sense data, the VALID bit indicates whether the

      * contents of the INFORMATION field is valid as defined by a command standard. Since the contents of the

      * INFORMATION field are valid whenever an information sense data descriptor is included in the sense data, the only

      * legal value for the VALID bit is set to one.

      */

     private final boolean valid = true;

     /**

      * This field may contain additional information (but doesn't).

      */

     private final EightByteInformation information;

     /**

      * The constructor.

      * 

      * @param information {@link EightByteInformation} that may contain useful information

      */

     public InformationSenseDataDescriptor (final EightByteInformation information) {

         super(SenseDataDescriptorType.INFORMATION, // descriptor type

         0x0a); // additional length

         this.information = information;

     }

     @Override

     protected final void serializeSpecificFields (final ByteBuffer byteBuffer, final int index) {

         byte b = 0;

         // valid bit

         if (valid) b = BitManip.getByteWithBitSet(b, 7, true);

         byteBuffer.put(index + VALID_FLAG_BYTE_INDEX, b);

         // information

         information.serialize(byteBuffer, index + INFORMATION_INDEX);

     }

 }