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

 import java.nio.ByteBuffer;

 import org.jscsi.target.scsi.cdb.CommandDescriptorBlock;

 import org.jscsi.target.util.BitManip;

 import org.jscsi.target.util.ReadWrite;

 /**

  * Field pointer sense-key-specific data is used to indicate that a certain field of a received command descriptor block

  * contained an illegal value.

  * 

  * @see CommandDescriptorBlock

  * @author Andreas Ergenzinger

  */

 public final class FieldPointerSenseKeySpecificData extends SenseKeySpecificData {

     /**

      * A command data (C/D) bit set to one indicates that the illegal parameter is in the CDB. A C/D bit set to zero

      * indicates that the illegal parameter is in the data parameters sent by the application client in the Data-Out

      * Buffer.

      */

     private final boolean commandData;

     /**

      * A bit pointer valid (BPV) bit set to zero indicates that the value in the BIT POINTER field is not valid.

      */

     private final boolean bitPointerValid;

     /**

      * If {@link #bitPointerValid} is <code>true</code>, the BIT POINTER field specifies which bit of the byte

      * designated by the FIELD POINTER field is in error. When a multiple-bit field is in error, the BIT POINTER field

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

      */

     private final int bitPointer;

     /**

      * The FIELD POINTER field indicates which byte of the CDB or of the parameter data was in error. Bytes are numbered

      * starting from zero, as shown in the tables describing the commands and parameters. When a multiple-byte field is

      * in error, the field pointer shall point to the first byte (i.e., the left-most byte) of the field. If several

      * consecutive bytes are reserved, each shall be treated as a single-byte field.

      */

     private final short fieldPointer;

     public FieldPointerSenseKeySpecificData (final boolean senseKeySpecificDataValid, final boolean commandData, final boolean bitPointerValid, final int bitPointer, final int fieldPointer) {

         super(senseKeySpecificDataValid);

         this.commandData = commandData;

         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

         // command data

         b = BitManip.getByteWithBitSet(b, 6, commandData);

         // 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());

     }

 }