usr/src/lib/krb5/dyn/dyn_delete.c

   1 #pragma ident   "%Z%%M% %I%     %E% SMI"
   2
   3 /*
   4  * This file is part of libdyn.a, the C Dynamic Object library.  It
   5  * contains the source code for the function DynDelete().
   6  *
   7  * There are no restrictions on this code; however, if you make any
   8  * changes, I request that you document them so that I do not get
   9  * credit or blame for your modifications.
  10  *
  11  * Written by Barr3y Jaspan, Student Information Processing Board (SIPB)
  12  * and MIT-Project Athena, 1989.
  13  * Copyright (c) 2016 by Delphix. All rights reserved.
  14  */
  15
  16 #include <stdio.h>
  17 #include <strings.h>
  18 #include <string.h>
  19
  20 #include "dynP.h"
  21
  22 /*
  23  * Checkers!  Get away from that "hard disk erase" button!
  24  *    (Stupid dog.  He almost did it to me again ...)
  25  */
  26 int DynDelete(obj, idx)
  27    DynObjectP obj;
  28    int idx;
  29 {
  30      if (idx < 0) {
  31           if (obj->debug)
  32                fprintf(stderr, "dyn: delete: bad index %d\n", idx);
  33           return DYN_BADINDEX;
  34      }
  35
  36      if (idx >= obj->num_el) {
  37           if (obj->debug)
  38                fprintf(stderr, "dyn: delete: Highest index is %d.\n",
  39                        obj->num_el);
  40           return DYN_BADINDEX;
  41      }
  42
  43      if (idx == obj->num_el-1) {
  44           if (obj->paranoid) {
  45                if (obj->debug)
  46                     fprintf(stderr, "dyn: delete: last element, zeroing.\n");
  47                memset(obj->array + idx*obj->el_size, 0, obj->el_size);
  48           }
  49           else {
  50                if (obj->debug)
  51                     fprintf(stderr, "dyn: delete: last element, punting.\n");
  52           }
  53      }
  54      else {
  55           if (obj->debug)
  56                fprintf(stderr,
  57                        "dyn: delete: copying %d bytes from %d + %d to + %d.\n",
  58                        obj->el_size*(obj->num_el - idx), obj->array,
  59                        (idx+1)*obj->el_size, idx*obj->el_size);
  60
  61 #ifdef HAVE_MEMMOVE
  62           memmove(obj->array + idx*obj->el_size,
  63                   obj->array + (idx+1)*obj->el_size,
  64                   obj->el_size*(obj->num_el - idx));
  65 #else
  66           bcopy(obj->array + (idx+1)*obj->el_size,
  67                   obj->array + idx*obj->el_size,
  68                   obj->el_size*(obj->num_el - idx));
  69 #endif
  70           if (obj->paranoid) {
  71                if (obj->debug)
  72                     fprintf(stderr,
  73                             "dyn: delete: zeroing %d bytes from %d + %d\n",
  74                             obj->el_size, obj->array,
  75                             obj->el_size*(obj->num_el - 1));
  76                memset(obj->array + obj->el_size*(obj->num_el - 1), 0,
  77                      obj->el_size);
  78           }
  79      }
  80
  81      --obj->num_el;
  82
  83      if (obj->debug)
  84           fprintf(stderr, "dyn: delete: done.\n");
  85
  86      return DYN_OK;
  87 }