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

 import java.nio.ByteBuffer;

 import org.jscsi.target.scsi.sense.SenseData;

 import org.jscsi.target.scsi.sense.SenseKey;

 import org.jscsi.target.scsi.sense.senseDataDescriptor.CommandSpecificSenseDataDescriptor;

 import org.jscsi.target.util.BitManip;

 import org.jscsi.target.util.ReadWrite;

 /**

  * Segment pointer sense-key-specific data is to be used, when the sense key of the enclosing {@link SenseData} has the

  * value {@link SenseKey#COPY_ABORTED}.

  * 

  * @author Andreas Ergenzinger

  */

 public class SegmentPointerSenseKeySpecificData extends SenseKeySpecificData {

     /**

      * The segment descriptor (SD) bit indicates whether the field pointer is relative to the start of the parameter

      * list or to the start of a segment descriptor. An SD bit set to zero indicates that the field pointer is relative

      * to the start of the parameter list. An SD bit set to one indicates that the field pointer is relative to the

      * start of the segment descriptor indicated by the third and fourth bytes of the

      * {@link CommandSpecificSenseDataDescriptor#commandSpecificInformation} field.

      */

     private final boolean segmentDescriptor;

     /**

      * A bit pointer valid (BPV) bit set to zero indicates that the value in the {@link #bitPointer} field is not valid.

      * A BPV bit set to one indicates that the {@link #bitPointer} field specifies which bit of the byte designated by

      * the {@link #fieldPointer} field is in error. When a multiple-bit field is in error, the {@link #bitPointerValid}

      * field shall point to the most-significant (i.e., left-most) bit of the field.

      */

     private final boolean bitPointerValid;

     /**

      * The FIELD POINTER field indicates which byte of the parameter list or segment descriptor was in error.

      * 

      * @see #bitPointerValid

      */

     private final short fieldPointer;

     /**

      * Points to the leftmost bit of the field in error.

      * 

      * @see #bitPointerValid

      */

     private final int bitPointer;

     /**

      * The constructor.

      * <p>

      * All parameters are used to initialize the member variables with the same name.

      * 

      * @param senseKeySpecificDataValid

      * @param segmentDescriptor

      * @param bitPointerValid

      * @param bitPointer

      * @param fieldPointer

      */

     public SegmentPointerSenseKeySpecificData (final boolean senseKeySpecificDataValid, final boolean segmentDescriptor, final boolean bitPointerValid, final int bitPointer, final int fieldPointer) {

         super(senseKeySpecificDataValid);

         this.segmentDescriptor = segmentDescriptor;

         this.bitPointerValid = bitPointerValid;

         this.bitPointer = bitPointer;

         this.fieldPointer = (short) fieldPointer;

     }

     @Override

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

         byte b = byteBuffer.get(index);// SKSV bit has already been set and has

                                        // to be preserved

         // segment descriptor

         b = BitManip.getByteWithBitSet(b, 5, segmentDescriptor);

         // bit pointer valid

         b = BitManip.getByteWithBitSet(b, 3, bitPointerValid);

         // bit pointer

         b &= (bitPointer & 7);

         // store first byte

         byteBuffer.put(index, b);

         // field pointer

         ReadWrite.writeTwoByteInt(byteBuffer, fieldPointer, byteBuffer.position());

     }

 }