Annotation of src/usr.bin/asn1_compile/hash.c, Revision 1.3
1.1 hin 1: /*
2: * Copyright (c) 1997 Kungliga Tekniska Högskolan
3: * (Royal Institute of Technology, Stockholm, Sweden).
4: * All rights reserved.
5: *
6: * Redistribution and use in source and binary forms, with or without
7: * modification, are permitted provided that the following conditions
8: * are met:
9: *
10: * 1. Redistributions of source code must retain the above copyright
11: * notice, this list of conditions and the following disclaimer.
12: *
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.
16: *
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.
20: *
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.
32: */
33:
34: /*
35: * Hash table functions
36: */
37:
38: #include "gen_locl.h"
39:
40: /*
41: RCSID("$KTH: hash.c,v 1.8 1999/12/02 17:05:02 joda Exp $");
42: */
43:
44: static Hashentry *_search(Hashtab * htab, /* The hash table */
45: void *ptr); /* And key */
46:
47: Hashtab *
48: hashtabnew(int sz,
49: int (*cmp) (void *, void *),
50: unsigned (*hash) (void *))
51: {
52: Hashtab *htab;
53: int i;
54:
55: assert(sz > 0);
56:
57: htab = (Hashtab *) malloc(sizeof(Hashtab) + (sz - 1) * sizeof(Hashentry *));
58:
59: if (htab == NULL) {
60: return NULL;
61: } else {
1.3 ! jaredy 62: for (i = 0; i < sz; ++i)
! 63: htab->tab[i] = NULL;
1.1 hin 64: htab->cmp = cmp;
65: htab->hash = hash;
66: htab->sz = sz;
67: return htab;
68: }
69: }
70:
71: /* Intern search function */
72:
73: static Hashentry *
74: _search(Hashtab * htab, void *ptr)
75: {
76: Hashentry *hptr;
77:
78: assert(htab && ptr);
79:
80: for (hptr = htab->tab[(*htab->hash) (ptr) % htab->sz];
81: hptr;
82: hptr = hptr->next)
83: if ((*htab->cmp) (ptr, hptr->ptr) == 0)
84: break;
85: return hptr;
86: }
87:
88: /* Search for element in hash table */
89:
90: void *
91: hashtabsearch(Hashtab * htab, void *ptr)
92: {
93: Hashentry *tmp;
94:
95: tmp = _search(htab, ptr);
96: return tmp ? tmp->ptr : tmp;
97: }
98:
99: /* add element to hash table */
100: /* if already there, set new value */
1.2 jmc 101: /* !NULL if successful */
1.1 hin 102:
103: void *
104: hashtabadd(Hashtab * htab, void *ptr)
105: {
106: Hashentry *h = _search(htab, ptr);
107: Hashentry **tabptr;
108:
109: assert(htab && ptr);
110:
111: if (h)
112: free((void *) h->ptr);
113: else {
114: h = (Hashentry *) malloc(sizeof(Hashentry));
115: if (h == NULL) {
116: return NULL;
117: }
118: tabptr = &htab->tab[(*htab->hash) (ptr) % htab->sz];
119: h->next = *tabptr;
120: *tabptr = h;
121: h->prev = tabptr;
122: if (h->next)
123: h->next->prev = &h->next;
124: }
125: h->ptr = ptr;
126: return h;
127: }
128:
129: /* delete element with key key. Iff freep, free Hashentry->ptr */
130:
131: int
132: _hashtabdel(Hashtab * htab, void *ptr, int freep)
133: {
134: Hashentry *h;
135:
136: assert(htab && ptr);
137:
138: h = _search(htab, ptr);
139: if (h) {
140: if (freep)
141: free(h->ptr);
142: if ((*(h->prev) = h->next))
143: h->next->prev = h->prev;
144: free(h);
145: return 0;
146: } else
147: return -1;
148: }
149:
150: /* Do something for each element */
151:
152: void
153: hashtabforeach(Hashtab * htab, int (*func) (void *ptr, void *arg),
154: void *arg)
155: {
156: Hashentry **h, *g;
157:
158: assert(htab);
159:
160: for (h = htab->tab; h < &htab->tab[htab->sz]; ++h)
161: for (g = *h; g; g = g->next)
162: if ((*func) (g->ptr, arg))
163: return;
164: }
165:
166: /* standard hash-functions for strings */
167:
168: unsigned
169: hashadd(const char *s)
170: { /* Standard hash function */
171: unsigned i;
172:
173: assert(s);
174:
175: for (i = 0; *s; ++s)
176: i += *s;
177: return i;
178: }
179:
180: unsigned
181: hashcaseadd(const char *s)
182: { /* Standard hash function */
183: unsigned i;
184:
185: assert(s);
186:
187: for (i = 0; *s; ++s)
188: i += toupper(*s);
189: return i;
190: }
191:
192: #define TWELVE (sizeof(unsigned))
193: #define SEVENTYFIVE (6*sizeof(unsigned))
194: #define HIGH_BITS (~((unsigned)(~0) >> TWELVE))
195:
196: unsigned
197: hashjpw(const char *ss)
198: { /* another hash function */
199: unsigned h = 0;
200: unsigned g;
201: const unsigned char *s = (const unsigned char *)ss;
202:
203: for (; *s; ++s) {
204: h = (h << TWELVE) + *s;
205: if ((g = h & HIGH_BITS))
206: h = (h ^ (g >> SEVENTYFIVE)) & ~HIGH_BITS;
207: }
208: return h;
209: }
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