Turned the inquiryCDB struct into a class, with auto setting of the opcode...

Turned the inquiryCDB struct into a class, with auto setting of the opcode (which is always the same) and adapted the usage.

Drive/Drive.hh

@@ -88,10 +88,8 @@ namespace Tape {
       unsigned char dataBuff[130];
       unsigned char senseBuff[256];
       SCSI::Structures::inquiryCDB_t cdb; 
-      memset(&cdb, 0, sizeof (cdb));
       memset(&dataBuff, 0, sizeof (dataBuff));
-      /* Build command */
-      cdb.opCode = SCSI::Commands::INQUIRY;
+      /* Build command: nothing to do. We go with defaults. */
 
       sg_io_hdr_t sgh;
       memset(&sgh, 0, sizeof (sgh));

SCSI/Constants.hh

@@ -21,6 +21,8 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.*
  ************************************************************************/
 
+#pragma once
+
 namespace SCSI {
   /* Extracted from linux kernel's include/scsi/scsi.h. System-level include 
    is less complete */

SCSI/Structures.hh

@@ -28,6 +28,8 @@
 #include <algorithm>
 #include <arpa/inet.h>
 
+#include "Constants.hh"
+
 namespace SCSI {
   /**
    * Structures as defined in the SCSI specifications, and helper functions for them.
@@ -38,11 +40,11 @@ namespace SCSI {
    * http://hackipedia.org/Hardware/SCSI/Stream%20Commands/SCSI%20Stream%20Commands%20-%203.pdf
    */
   namespace Structures {
-
     /*
      * Inquiry CDB as described in SPC-4.
      */
-    typedef struct {
+    class inquiryCDB_t {
+    public:
       unsigned char opCode;
       
       unsigned char EVPD : 1;
@@ -53,7 +55,8 @@ namespace SCSI {
       char allocationLength[2];
       
       unsigned char control;
-    } inquiryCDB_t;
+      inquiryCDB_t() { memset(this, 0, sizeof(*this)); opCode = SCSI::Commands::INQUIRY; }
+    };
     
     /*
      * Inquiry data as described in SPC-4.

SCSI/StructuresTest.cc

@@ -105,14 +105,17 @@ namespace UnitTests {
 
   TEST(SCSI_Structures, inquiryCDB_t) {
     SCSI::Structures::inquiryCDB_t inqCDB;
-    memset(&inqCDB, 0, sizeof(inqCDB));
     unsigned char *buff = (unsigned char *)&inqCDB;
     
+    /*
+     * Make sure this struct is a POD (plain old data without virtual table)
+     * (and has the right size).
+     */
     ASSERT_EQ(6, sizeof(inqCDB));
     
-    ASSERT_EQ(0, inqCDB.opCode);
-    buff[0] = SCSI::Commands::INQUIRY;
     ASSERT_EQ(SCSI::Commands::INQUIRY, inqCDB.opCode);
+    buff[0] = 0;
+    ASSERT_EQ(0, inqCDB.opCode);
     
     ASSERT_EQ(0, inqCDB.EVPD);
     buff[1] = 0x1;