1 package org.jscsi.target.scsi.cdb;
2
3
4 import java.nio.ByteBuffer;
5
6
7 /**
8 * This is an abstract super-class for command descriptor blocks that that are used for requesting information about the
9 * capacity of the storage device.
10 *
11 * @author Andreas Ergenzinger
12 */
13 public abstract class ReadCapacityCdb extends CommandDescriptorBlock {
14
15 /**
16 * The LOGICAL BLOCK ADDRESS field specifies the LBA of the first logical block accessed by this command.
17 * <p>
18 * If the specified LBA exceeds the capacity of the medium, then the device server shall terminate the command with
19 * CHECK CONDITION status with the sense key set to ILLEGAL REQUEST and the additional sense code set to LOGICAL
20 * BLOCK ADDRESS OUT OF RANGE.
21 *
22 * @see #partialMediumIndicator
23 */
24 protected final long logicalBlockAddress;
25
26 /**
27 * A partial medium indicator (PMI) bit set to zero specifies that the device server return information on the last
28 * logical block on the direct-access block device.
29 * <p>
30 * A PMI bit set to one specifies that the device server return information on the last logical block after that
31 * specified in the LOGICAL BLOCK ADDRESS field before a substantial vendor specific delay in data transfer may be
32 * encountered.
33 * <p>
34 * The LOGICAL BLOCK ADDRESS field shall be set to zero if the PMI bit is set to zero. If the PMI bit is set to zero
35 * and the LOGICAL BLOCK ADDRESS field is not set to zero, then the device server shall terminate the command with
36 * CHECK CONDITION status with the sense key set to ILLEGAL REQUEST and the additional sense code set to INVALID
37 * FIELD IN CDB.
38 *
39 * @see #logicalBlockAddress
40 */
41 protected final boolean partialMediumIndicator;
42
43 public ReadCapacityCdb (final ByteBuffer buffer) {
44 super(buffer);
45 logicalBlockAddress = deserializeLogicalBlockAddress(buffer);
46 partialMediumIndicator = deserializePartialMediumIndicator(buffer);
47 // check constraint
48 if (!partialMediumIndicator && logicalBlockAddress > 0) addIllegalFieldPointer(2);
49 }
50
51 protected abstract long deserializeLogicalBlockAddress (ByteBuffer buffer);
52
53 protected abstract boolean deserializePartialMediumIndicator (ByteBuffer buffer);
54
55 public final long getLogicalBlockAddress () {
56 return logicalBlockAddress;
57 }
58
59 public final boolean getPartialMediumIndicator () {
60 return partialMediumIndicator;
61 }
62 }