usr/src/lib/krb5/dyn/dyn_realloc.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 internal function _DynRealloc().
   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  */
  14
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17
  18 #include "dynP.h"
  19
  20 /*
  21  * Resize the array so that element req exists.
  22  */
  23 int _DynResize(obj, req)
  24    DynObjectP obj;
  25    int req;
  26 {
  27      int cnt, size;
  28
  29      if (obj->size > req)
  30           return DYN_OK;
  31      else if (obj->inc > 0)
  32           return _DynRealloc(obj, (req - obj->size) / obj->inc + 1);
  33      else {
  34           if (obj->size == 0)
  35                size = -obj->inc;
  36           else
  37                size = obj->size;
  38
  39           while (size <= req)
  40                size <<= 1;
  41
  42           return _DynRealloc(obj, size);
  43      }
  44 }
  45
  46 /*
  47  * Resize the array by num_incs units.  If obj->inc is positive, this
  48  * means make it obj->inc*num_incs elements larger.  If obj->inc is
  49  * negative, this means make the array num_incs elements long.
  50  *
  51  * Ideally, this function should not be called from outside the
  52  * library.  However, nothing will break if it is.
  53  */
  54 int _DynRealloc(obj, num_incs)
  55    DynObjectP obj;
  56    int num_incs;
  57 {
  58      DynPtr temp;
  59      int new_size_in_bytes;
  60
  61      if (obj->inc > 0)
  62           new_size_in_bytes = obj->el_size*(obj->size + obj->inc*num_incs);
  63      else
  64           new_size_in_bytes = obj->el_size*num_incs;
  65
  66      if (obj->debug)
  67           fprintf(stderr,
  68                   "dyn: alloc: Increasing object by %d bytes (%d incs).\n",
  69                   new_size_in_bytes - obj->el_size*obj->size,
  70                   num_incs);
  71
  72      temp = (DynPtr) realloc(obj->array, new_size_in_bytes);
  73      if (temp == NULL) {
  74           if (obj->debug)
  75                fprintf(stderr, "dyn: alloc: Out of memory.\n");
  76           return DYN_NOMEM;
  77      }
  78      else {
  79           obj->array = temp;
  80           if (obj->inc > 0)
  81                obj->size += obj->inc*num_incs;
  82           else
  83                obj->size = num_incs;
  84      }
  85
  86      if (obj->debug)
  87           fprintf(stderr, "dyn: alloc: done.\n");
  88
  89      return DYN_OK;
  90 }