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Diffstat (limited to 'lib/asn1/hash.c')
| -rw-r--r-- | lib/asn1/hash.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/lib/asn1/hash.c b/lib/asn1/hash.c new file mode 100644 index 0000000..eeb6b6d --- /dev/null +++ b/lib/asn1/hash.c @@ -0,0 +1,206 @@ +/* + * Copyright (c) 1997 Kungliga Tekniska Högskolan + * (Royal Institute of Technology, Stockholm, Sweden). + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * 3. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +/* + * Hash table functions + */ + +#include "gen_locl.h" + +RCSID("$Id: hash.c 17016 2006-04-07 22:16:00Z lha $"); + +static Hashentry *_search(Hashtab * htab, /* The hash table */ + void *ptr); /* And key */ + +Hashtab * +hashtabnew(int sz, + int (*cmp) (void *, void *), + unsigned (*hash) (void *)) +{ + Hashtab *htab; + int i; + + assert(sz > 0); + + htab = (Hashtab *) malloc(sizeof(Hashtab) + (sz - 1) * sizeof(Hashentry *)); + if (htab == NULL) + return NULL; + + for (i = 0; i < sz; ++i) + htab->tab[i] = NULL; + + htab->cmp = cmp; + htab->hash = hash; + htab->sz = sz; + return htab; +} + +/* Intern search function */ + +static Hashentry * +_search(Hashtab * htab, void *ptr) +{ + Hashentry *hptr; + + assert(htab && ptr); + + for (hptr = htab->tab[(*htab->hash) (ptr) % htab->sz]; + hptr; + hptr = hptr->next) + if ((*htab->cmp) (ptr, hptr->ptr) == 0) + break; + return hptr; +} + +/* Search for element in hash table */ + +void * +hashtabsearch(Hashtab * htab, void *ptr) +{ + Hashentry *tmp; + + tmp = _search(htab, ptr); + return tmp ? tmp->ptr : tmp; +} + +/* add element to hash table */ +/* if already there, set new value */ +/* !NULL if succesful */ + +void * +hashtabadd(Hashtab * htab, void *ptr) +{ + Hashentry *h = _search(htab, ptr); + Hashentry **tabptr; + + assert(htab && ptr); + + if (h) + free((void *) h->ptr); + else { + h = (Hashentry *) malloc(sizeof(Hashentry)); + if (h == NULL) { + return NULL; + } + tabptr = &htab->tab[(*htab->hash) (ptr) % htab->sz]; + h->next = *tabptr; + *tabptr = h; + h->prev = tabptr; + if (h->next) + h->next->prev = &h->next; + } + h->ptr = ptr; + return h; +} + +/* delete element with key key. Iff freep, free Hashentry->ptr */ + +int +_hashtabdel(Hashtab * htab, void *ptr, int freep) +{ + Hashentry *h; + + assert(htab && ptr); + + h = _search(htab, ptr); + if (h) { + if (freep) + free(h->ptr); + if ((*(h->prev) = h->next)) + h->next->prev = h->prev; + free(h); + return 0; + } else + return -1; +} + +/* Do something for each element */ + +void +hashtabforeach(Hashtab * htab, int (*func) (void *ptr, void *arg), + void *arg) +{ + Hashentry **h, *g; + + assert(htab); + + for (h = htab->tab; h < &htab->tab[htab->sz]; ++h) + for (g = *h; g; g = g->next) + if ((*func) (g->ptr, arg)) + return; +} + +/* standard hash-functions for strings */ + +unsigned +hashadd(const char *s) +{ /* Standard hash function */ + unsigned i; + + assert(s); + + for (i = 0; *s; ++s) + i += *s; + return i; +} + +unsigned +hashcaseadd(const char *s) +{ /* Standard hash function */ + unsigned i; + + assert(s); + + for (i = 0; *s; ++s) + i += toupper((unsigned char)*s); + return i; +} + +#define TWELVE (sizeof(unsigned)) +#define SEVENTYFIVE (6*sizeof(unsigned)) +#define HIGH_BITS (~((unsigned)(~0) >> TWELVE)) + +unsigned +hashjpw(const char *ss) +{ /* another hash function */ + unsigned h = 0; + unsigned g; + const unsigned char *s = (const unsigned char *)ss; + + for (; *s; ++s) { + h = (h << TWELVE) + *s; + if ((g = h & HIGH_BITS)) + h = (h ^ (g >> SEVENTYFIVE)) & ~HIGH_BITS; + } + return h; +} |
