external/bsd/bind/dist/lib/isccc/symtab.c

   1 /*      $NetBSD: symtab.c,v 1.4 2014/12/10 04:38:01 christos Exp $      */
   2
   3 /*
   4  * Portions Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
   5  * Portions Copyright (C) 2001  Internet Software Consortium.
   6  *
   7  * Permission to use, copy, modify, and/or distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
  12  * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  13  * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
  14  * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18  *
  19  * Portions Copyright (C) 2001  Nominum, Inc.
  20  *
  21  * Permission to use, copy, modify, and/or distribute this software for any
  22  * purpose with or without fee is hereby granted, provided that the above
  23  * copyright notice and this permission notice appear in all copies.
  24  *
  25  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
  26  * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  27  * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
  28  * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  29  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  30  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  31  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  32  */
  33
  34 /* Id: symtab.c,v 1.11 2007/09/13 04:45:18 each Exp  */
  35
  36 /*! \file */
  37
  38 #include <config.h>
  39
  40 #include <ctype.h>
  41 #include <stdlib.h>
  42
  43 #include <isc/assertions.h>
  44 #include <isc/magic.h>
  45 #include <isc/string.h>
  46
  47 #include <isccc/result.h>
  48 #include <isccc/symtab.h>
  49 #include <isccc/util.h>
  50
  51 typedef struct elt {
  52         char *                          key;
  53         unsigned int                    type;
  54         isccc_symvalue_t                        value;
  55         ISC_LINK(struct elt)            link;
  56 } elt_t;
  57
  58 typedef ISC_LIST(elt_t)                 eltlist_t;
  59
  60 #define SYMTAB_MAGIC                    ISC_MAGIC('S', 'y', 'm', 'T')
  61 #define VALID_SYMTAB(st)                ISC_MAGIC_VALID(st, SYMTAB_MAGIC)
  62
  63 struct isccc_symtab {
  64         unsigned int                    magic;
  65         unsigned int                    size;
  66         eltlist_t *                     table;
  67         isccc_symtabundefaction_t               undefine_action;
  68         void *                          undefine_arg;
  69         isc_boolean_t                   case_sensitive;
  70 };
  71
  72 isc_result_t
  73 isccc_symtab_create(unsigned int size,
  74                   isccc_symtabundefaction_t undefine_action,
  75                   void *undefine_arg,
  76                   isc_boolean_t case_sensitive,
  77                   isccc_symtab_t **symtabp)
  78 {
  79         isccc_symtab_t *symtab;
  80         unsigned int i;
  81
  82         REQUIRE(symtabp != NULL && *symtabp == NULL);
  83         REQUIRE(size > 0);      /* Should be prime. */
  84
  85         symtab = malloc(sizeof(*symtab));
  86         if (symtab == NULL)
  87                 return (ISC_R_NOMEMORY);
  88         symtab->table = malloc(size * sizeof(eltlist_t));
  89         if (symtab->table == NULL) {
  90                 free(symtab);
  91                 return (ISC_R_NOMEMORY);
  92         }
  93         for (i = 0; i < size; i++)
  94                 ISC_LIST_INIT(symtab->table[i]);
  95         symtab->size = size;
  96         symtab->undefine_action = undefine_action;
  97         symtab->undefine_arg = undefine_arg;
  98         symtab->case_sensitive = case_sensitive;
  99         symtab->magic = SYMTAB_MAGIC;
 100
 101         *symtabp = symtab;
 102
 103         return (ISC_R_SUCCESS);
 104 }
 105
 106 static inline void
 107 free_elt(isccc_symtab_t *symtab, unsigned int bucket, elt_t *elt) {
 108         ISC_LIST_UNLINK(symtab->table[bucket], elt, link);
 109         if (symtab->undefine_action != NULL)
 110                 (symtab->undefine_action)(elt->key, elt->type, elt->value,
 111                                           symtab->undefine_arg);
 112         free(elt);
 113 }
 114
 115 void
 116 isccc_symtab_destroy(isccc_symtab_t **symtabp) {
 117         isccc_symtab_t *symtab;
 118         unsigned int i;
 119         elt_t *elt, *nelt;
 120
 121         REQUIRE(symtabp != NULL);
 122         symtab = *symtabp;
 123         REQUIRE(VALID_SYMTAB(symtab));
 124
 125         for (i = 0; i < symtab->size; i++) {
 126                 for (elt = ISC_LIST_HEAD(symtab->table[i]);
 127                      elt != NULL;
 128                      elt = nelt) {
 129                         nelt = ISC_LIST_NEXT(elt, link);
 130                         free_elt(symtab, i, elt);
 131                 }
 132         }
 133         free(symtab->table);
 134         symtab->magic = 0;
 135         free(symtab);
 136
 137         *symtabp = NULL;
 138 }
 139
 140 static inline unsigned int
 141 hash(const char *key, isc_boolean_t case_sensitive) {
 142         const char *s;
 143         unsigned int h = 0;
 144         unsigned int g;
 145         int c;
 146
 147         /*
 148          * P. J. Weinberger's hash function, adapted from p. 436 of
 149          * _Compilers: Principles, Techniques, and Tools_, Aho, Sethi
 150          * and Ullman, Addison-Wesley, 1986, ISBN 0-201-10088-6.
 151          */
 152
 153         if (case_sensitive) {
 154                 for (s = key; *s != '\0'; s++) {
 155                         h = ( h << 4 ) + *s;
 156                         if ((g = ( h & 0xf0000000 )) != 0) {
 157                                 h = h ^ (g >> 24);
 158                                 h = h ^ g;
 159                         }
 160                 }
 161         } else {
 162                 for (s = key; *s != '\0'; s++) {
 163                         c = *s;
 164                         c = tolower((unsigned char)c);
 165                         h = ( h << 4 ) + c;
 166                         if ((g = ( h & 0xf0000000 )) != 0) {
 167                                 h = h ^ (g >> 24);
 168                                 h = h ^ g;
 169                         }
 170                 }
 171         }
 172
 173         return (h);
 174 }
 175
 176 #define FIND(s, k, t, b, e) \
 177         b = hash((k), (s)->case_sensitive) % (s)->size; \
 178         if ((s)->case_sensitive) { \
 179                 for (e = ISC_LIST_HEAD((s)->table[b]); \
 180                      e != NULL; \
 181                      e = ISC_LIST_NEXT(e, link)) { \
 182                         if (((t) == 0 || e->type == (t)) && \
 183                             strcmp(e->key, (k)) == 0) \
 184                                 break; \
 185                 } \
 186         } else { \
 187                 for (e = ISC_LIST_HEAD((s)->table[b]); \
 188                      e != NULL; \
 189                      e = ISC_LIST_NEXT(e, link)) { \
 190                         if (((t) == 0 || e->type == (t)) && \
 191                             strcasecmp(e->key, (k)) == 0) \
 192                                 break; \
 193                 } \
 194         }
 195
 196 isc_result_t
 197 isccc_symtab_lookup(isccc_symtab_t *symtab, const char *key, unsigned int type,
 198                   isccc_symvalue_t *value)
 199 {
 200         unsigned int bucket;
 201         elt_t *elt;
 202
 203         REQUIRE(VALID_SYMTAB(symtab));
 204         REQUIRE(key != NULL);
 205
 206         FIND(symtab, key, type, bucket, elt);
 207
 208         if (elt == NULL)
 209                 return (ISC_R_NOTFOUND);
 210
 211         if (value != NULL)
 212                 *value = elt->value;
 213
 214         return (ISC_R_SUCCESS);
 215 }
 216
 217 isc_result_t
 218 isccc_symtab_define(isccc_symtab_t *symtab, char *key, unsigned int type,
 219                   isccc_symvalue_t value, isccc_symexists_t exists_policy)
 220 {
 221         unsigned int bucket;
 222         elt_t *elt;
 223
 224         REQUIRE(VALID_SYMTAB(symtab));
 225         REQUIRE(key != NULL);
 226         REQUIRE(type != 0);
 227
 228         FIND(symtab, key, type, bucket, elt);
 229
 230         if (exists_policy != isccc_symexists_add && elt != NULL) {
 231                 if (exists_policy == isccc_symexists_reject)
 232                         return (ISC_R_EXISTS);
 233                 INSIST(exists_policy == isccc_symexists_replace);
 234                 ISC_LIST_UNLINK(symtab->table[bucket], elt, link);
 235                 if (symtab->undefine_action != NULL)
 236                         (symtab->undefine_action)(elt->key, elt->type,
 237                                                   elt->value,
 238                                                   symtab->undefine_arg);
 239         } else {
 240                 elt = malloc(sizeof(*elt));
 241                 if (elt == NULL)
 242                         return (ISC_R_NOMEMORY);
 243                 ISC_LINK_INIT(elt, link);
 244         }
 245
 246         elt->key = key;
 247         elt->type = type;
 248         elt->value = value;
 249
 250         /*
 251          * We prepend so that the most recent definition will be found.
 252          */
 253         ISC_LIST_PREPEND(symtab->table[bucket], elt, link);
 254
 255         return (ISC_R_SUCCESS);
 256 }
 257
 258 isc_result_t
 259 isccc_symtab_undefine(isccc_symtab_t *symtab, const char *key, unsigned int type) {
 260         unsigned int bucket;
 261         elt_t *elt;
 262
 263         REQUIRE(VALID_SYMTAB(symtab));
 264         REQUIRE(key != NULL);
 265
 266         FIND(symtab, key, type, bucket, elt);
 267
 268         if (elt == NULL)
 269                 return (ISC_R_NOTFOUND);
 270
 271         free_elt(symtab, bucket, elt);
 272
 273         return (ISC_R_SUCCESS);
 274 }
 275
 276 void
 277 isccc_symtab_foreach(isccc_symtab_t *symtab, isccc_symtabforeachaction_t action,
 278                    void *arg)
 279 {
 280         unsigned int i;
 281         elt_t *elt, *nelt;
 282
 283         REQUIRE(VALID_SYMTAB(symtab));
 284         REQUIRE(action != NULL);
 285
 286         for (i = 0; i < symtab->size; i++) {
 287                 for (elt = ISC_LIST_HEAD(symtab->table[i]);
 288                      elt != NULL;
 289                      elt = nelt) {
 290                         nelt = ISC_LIST_NEXT(elt, link);
 291                         if ((action)(elt->key, elt->type, elt->value, arg))
 292                                 free_elt(symtab, i, elt);
 293                 }
 294         }
 295 }