coverity 1164099
[heimdal.git] / lib / asn1 / hash.c
blob73b6cf97c42367d99f2605f45c3e7375968db3d3
1 /*
2 * Copyright (c) 1997 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the Institute nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
35 * Hash table functions
38 #include "gen_locl.h"
40 RCSID("$Id$");
42 static Hashentry *_search(Hashtab * htab, /* The hash table */
43 void *ptr); /* And key */
45 Hashtab *
46 hashtabnew(int sz,
47 int (*cmp) (void *, void *),
48 unsigned (*hash) (void *))
50 Hashtab *htab;
51 int i;
53 assert(sz > 0);
55 htab = (Hashtab *) malloc(sizeof(Hashtab) + (sz - 1) * sizeof(Hashentry *));
56 if (htab == NULL)
57 return NULL;
59 for (i = 0; i < sz; ++i)
60 htab->tab[i] = NULL;
62 htab->cmp = cmp;
63 htab->hash = hash;
64 htab->sz = sz;
65 return htab;
68 /* Intern search function */
70 static Hashentry *
71 _search(Hashtab * htab, void *ptr)
73 Hashentry *hptr;
75 assert(htab && ptr);
77 for (hptr = htab->tab[(*htab->hash) (ptr) % htab->sz];
78 hptr;
79 hptr = hptr->next)
80 if ((*htab->cmp) (ptr, hptr->ptr) == 0)
81 break;
82 return hptr;
85 /* Search for element in hash table */
87 void *
88 hashtabsearch(Hashtab * htab, void *ptr)
90 Hashentry *tmp;
92 tmp = _search(htab, ptr);
93 return tmp ? tmp->ptr : tmp;
96 /* add element to hash table */
97 /* if already there, set new value */
98 /* !NULL if succesful */
100 void *
101 hashtabadd(Hashtab * htab, void *ptr)
103 Hashentry *h = _search(htab, ptr);
104 Hashentry **tabptr;
106 assert(htab && ptr);
108 if (h)
109 free((void *) h->ptr);
110 else {
111 h = (Hashentry *) malloc(sizeof(Hashentry));
112 if (h == NULL) {
113 return NULL;
115 tabptr = &htab->tab[(*htab->hash) (ptr) % htab->sz];
116 h->next = *tabptr;
117 *tabptr = h;
118 h->prev = tabptr;
119 if (h->next)
120 h->next->prev = &h->next;
122 h->ptr = ptr;
123 return h;
126 /* delete element with key key. Iff freep, free Hashentry->ptr */
129 _hashtabdel(Hashtab * htab, void *ptr, int freep)
131 Hashentry *h;
133 assert(htab && ptr);
135 h = _search(htab, ptr);
136 if (h) {
137 if (freep)
138 free(h->ptr);
139 if ((*(h->prev) = h->next))
140 h->next->prev = h->prev;
141 free(h);
142 return 0;
143 } else
144 return -1;
147 /* Do something for each element */
149 void
150 hashtabforeach(Hashtab * htab, int (*func) (void *ptr, void *arg),
151 void *arg)
153 Hashentry **h, *g;
155 assert(htab);
157 for (h = htab->tab; h < &htab->tab[htab->sz]; ++h)
158 for (g = *h; g; g = g->next)
159 if ((*func) (g->ptr, arg))
160 return;
163 /* standard hash-functions for strings */
165 unsigned
166 hashadd(const char *s)
167 { /* Standard hash function */
168 unsigned i;
170 assert(s);
172 for (i = 0; *s; ++s)
173 i += *s;
174 return i;
177 unsigned
178 hashcaseadd(const char *s)
179 { /* Standard hash function */
180 unsigned i;
182 assert(s);
184 for (i = 0; *s; ++s)
185 i += toupper((unsigned char)*s);
186 return i;
189 #define TWELVE (sizeof(unsigned))
190 #define SEVENTYFIVE (6*sizeof(unsigned))
191 #define HIGH_BITS (~((unsigned)(~0) >> TWELVE))
193 unsigned
194 hashjpw(const char *ss)
195 { /* another hash function */
196 unsigned h = 0;
197 unsigned g;
198 const unsigned char *s = (const unsigned char *)ss;
200 for (; *s; ++s) {
201 h = (h << TWELVE) + *s;
202 if ((g = h & HIGH_BITS))
203 h = (h ^ (g >> SEVENTYFIVE)) & ~HIGH_BITS;
205 return h;