libsecurity_smime/lib/cmsarray.c

   1 /*
   2  * The contents of this file are subject to the Mozilla Public
   3  * License Version 1.1 (the "License"); you may not use this file
   4  * except in compliance with the License. You may obtain a copy of
   5  * the License at http://www.mozilla.org/MPL/
   6  *
   7  * Software distributed under the License is distributed on an "AS
   8  * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
   9  * implied. See the License for the specific language governing
  10  * rights and limitations under the License.
  11  *
  12  * The Original Code is the Netscape security libraries.
  13  *
  14  * The Initial Developer of the Original Code is Netscape
  15  * Communications Corporation.  Portions created by Netscape are
  16  * Copyright (C) 1994-2000 Netscape Communications Corporation.  All
  17  * Rights Reserved.
  18  *
  19  * Contributor(s):
  20  *
  21  * Alternatively, the contents of this file may be used under the
  22  * terms of the GNU General Public License Version 2 or later (the
  23  * "GPL"), in which case the provisions of the GPL are applicable
  24  * instead of those above.  If you wish to allow use of your
  25  * version of this file only under the terms of the GPL and not to
  26  * allow others to use your version of this file under the MPL,
  27  * indicate your decision by deleting the provisions above and
  28  * replace them with the notice and other provisions required by
  29  * the GPL.  If you do not delete the provisions above, a recipient
  30  * may use your version of this file under either the MPL or the
  31  * GPL.
  32  */
  33
  34 /*
  35  * CMS array functions.
  36  */
  37
  38 #include "cmslocal.h"
  39
  40 #include <security_asn1/secerr.h>
  41
  42 /*
  43  * ARRAY FUNCTIONS
  44  *
  45  * In NSS, arrays are rather primitive arrays of pointers.
  46  * Makes it easy to walk the array, but hard to count elements
  47  * and manage the storage.
  48  *
  49  * This is a feeble attempt to encapsulate the functionality
  50  * and get rid of hundreds of lines of similar code
  51  */
  52
  53 /*
  54  * SecCmsArrayAlloc - allocate an array in an arena
  55  *
  56  * This allocates space for the array of pointers
  57  */
  58 void **
  59 SecCmsArrayAlloc(PRArenaPool *poolp, int n)
  60 {
  61     return (void **)PORT_ArenaZAlloc(poolp, n * sizeof(void *));
  62 }
  63
  64 /*
  65  * SecCmsArrayAdd - add an element to the end of an array
  66  *
  67  * The array of pointers is either created (if array was empty before) or grown.
  68  */
  69 OSStatus
  70 SecCmsArrayAdd(PRArenaPool *poolp, void ***array, void *obj)
  71 {
  72     void **p;
  73     int n;
  74     void **dest;
  75
  76     PORT_Assert(array != NULL);
  77     if (array == NULL)
  78         return SECFailure;
  79
  80     if (*array == NULL) {
  81         dest = (void **)PORT_ArenaAlloc(poolp, 2 * sizeof(void *));
  82         n = 0;
  83     } else {
  84         n = 0; p = *array;
  85         while (*p++)
  86             n++;
  87         dest = (void **)PORT_ArenaGrow (poolp,
  88                               *array,
  89                               (n + 1) * sizeof(void *),
  90                               (n + 2) * sizeof(void *));
  91     }
  92
  93     if (dest == NULL)
  94         return SECFailure;
  95
  96     dest[n] = obj;
  97     dest[n+1] = NULL;
  98     *array = dest;
  99     return SECSuccess;
 100 }
 101
 102 /*
 103  * SecCmsArrayIsEmpty - check if array is empty
 104  */
 105 Boolean
 106 SecCmsArrayIsEmpty(void **array)
 107 {
 108     return (array == NULL || array[0] == NULL);
 109 }
 110
 111 /*
 112  * SecCmsArrayCount - count number of elements in array
 113  */
 114 int
 115 SecCmsArrayCount(void **array)
 116 {
 117     int n = 0;
 118
 119     if (array == NULL)
 120         return 0;
 121
 122     while (*array++ != NULL)
 123         n++;
 124
 125     return n;
 126 }
 127
 128 /*
 129  * SecCmsArraySort - sort an array in place
 130  *
 131  * If "secondary" or "tertiary are not NULL, it must be arrays with the same
 132  *  number of elements as "primary". The same reordering will get applied to it.
 133  *
 134  * "compare" is a function that returns
 135  *  < 0 when the first element is less than the second
 136  *  = 0 when the first element is equal to the second
 137  *  > 0 when the first element is greater than the second
 138  * to acheive ascending ordering.
 139  */
 140 void
 141 SecCmsArraySort(void **primary, int (*compare)(void *,void *), void **secondary, void **tertiary)
 142 {
 143     int n, i, limit, lastxchg;
 144     void *tmp;
 145
 146     n = SecCmsArrayCount(primary);
 147
 148     PORT_Assert(secondary == NULL || SecCmsArrayCount(secondary) == n);
 149     PORT_Assert(tertiary == NULL || SecCmsArrayCount(tertiary) == n);
 150
 151     if (n <= 1) /* ordering is fine */
 152         return;
 153
 154     /* yes, ladies and gentlemen, it's BUBBLE SORT TIME! */
 155     limit = n - 1;
 156     while (1) {
 157         lastxchg = 0;
 158         for (i = 0; i < limit; i++) {
 159             if ((*compare)(primary[i], primary[i+1]) > 0) {
 160                 /* exchange the neighbours */
 161                 tmp = primary[i+1];
 162                 primary[i+1] = primary[i];
 163                 primary[i] = tmp;
 164                 if (secondary) {                /* secondary array? */
 165                     tmp = secondary[i+1];       /* exchange there as well */
 166                     secondary[i+1] = secondary[i];
 167                     secondary[i] = tmp;
 168                 }
 169                 if (tertiary) {                 /* tertiary array? */
 170                     tmp = tertiary[i+1];        /* exchange there as well */
 171                     tertiary[i+1] = tertiary[i];
 172                     tertiary[i] = tmp;
 173                 }
 174                 lastxchg = i+1; /* index of the last element bubbled up */
 175             }
 176         }
 177         if (lastxchg == 0)      /* no exchanges, so array is sorted */
 178             break;              /* we're done */
 179         limit = lastxchg;       /* array is sorted up to [limit] */
 180     }
 181 }
 182
 183 #if 0
 184
 185 /* array iterator stuff... not used */
 186
 187 typedef void **SecCmsArrayIterator;
 188
 189 /* iterator */
 190 SecCmsArrayIterator
 191 SecCmsArrayFirst(void **array)
 192 {
 193     if (array == NULL || array[0] == NULL)
 194         return NULL;
 195     return (SecCmsArrayIterator)&(array[0]);
 196 }
 197
 198 void *
 199 SecCmsArrayObj(SecCmsArrayIterator iter)
 200 {
 201     void **p = (void **)iter;
 202
 203     return *iter;       /* which is NULL if we are at the end of the array */
 204 }
 205
 206 SecCmsArrayIterator
 207 SecCmsArrayNext(SecCmsArrayIterator iter)
 208 {
 209     void **p = (void **)iter;
 210
 211     return (SecCmsArrayIterator)(p + 1);
 212 }
 213
 214 #endif