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 RCSID("$Id$");
41
42 static Hashentry *_search(Hashtab * htab, /* The hash table */
43 void *ptr); /* And key */
44
45 Hashtab *
hashtabnew(int sz,int (* cmp)(void *,void *),unsigned (* hash)(void *))46 hashtabnew(int sz,
47 int (*cmp) (void *, void *),
48 unsigned (*hash) (void *))
49 {
50 Hashtab *htab;
51 int i;
52
53 assert(sz > 0);
54
55 htab = (Hashtab *) malloc(sizeof(Hashtab) + (sz - 1) * sizeof(Hashentry *));
56 if (htab == NULL)
57 return NULL;
58
59 for (i = 0; i < sz; ++i)
60 htab->tab[i] = NULL;
61
62 htab->cmp = cmp;
63 htab->hash = hash;
64 htab->sz = sz;
65 return htab;
66 }
67
68 /* Intern search function */
69
70 static Hashentry *
_search(Hashtab * htab,void * ptr)71 _search(Hashtab * htab, void *ptr)
72 {
73 Hashentry *hptr;
74
75 assert(htab && ptr);
76
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;
83 }
84
85 /* Search for element in hash table */
86
87 void *
hashtabsearch(Hashtab * htab,void * ptr)88 hashtabsearch(Hashtab * htab, void *ptr)
89 {
90 Hashentry *tmp;
91
92 tmp = _search(htab, ptr);
93 return tmp ? tmp->ptr : tmp;
94 }
95
96 /* add element to hash table */
97 /* if already there, set new value */
98 /* !NULL if succesful */
99
100 void *
hashtabadd(Hashtab * htab,void * ptr)101 hashtabadd(Hashtab * htab, void *ptr)
102 {
103 Hashentry *h = _search(htab, ptr);
104 Hashentry **tabptr;
105
106 assert(htab && ptr);
107
108 if (h)
109 free((void *) h->ptr);
110 else {
111 h = (Hashentry *) malloc(sizeof(Hashentry));
112 if (h == NULL) {
113 return NULL;
114 }
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;
121 }
122 h->ptr = ptr;
123 return h;
124 }
125
126 /* delete element with key key. Iff freep, free Hashentry->ptr */
127
128 int
_hashtabdel(Hashtab * htab,void * ptr,int freep)129 _hashtabdel(Hashtab * htab, void *ptr, int freep)
130 {
131 Hashentry *h;
132
133 assert(htab && ptr);
134
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;
145 }
146
147 /* Do something for each element */
148
149 void
hashtabforeach(Hashtab * htab,int (* func)(void * ptr,void * arg),void * arg)150 hashtabforeach(Hashtab * htab, int (*func) (void *ptr, void *arg),
151 void *arg)
152 {
153 Hashentry **h, *g;
154
155 assert(htab);
156
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;
161 }
162
163 /* standard hash-functions for strings */
164
165 unsigned
hashadd(const char * s)166 hashadd(const char *s)
167 { /* Standard hash function */
168 unsigned i;
169
170 assert(s);
171
172 for (i = 0; *s; ++s)
173 i += *s;
174 return i;
175 }
176
177 unsigned
hashcaseadd(const char * s)178 hashcaseadd(const char *s)
179 { /* Standard hash function */
180 unsigned i;
181
182 assert(s);
183
184 for (i = 0; *s; ++s)
185 i += toupper((unsigned char)*s);
186 return i;
187 }
188
189 #define TWELVE (sizeof(unsigned))
190 #define SEVENTYFIVE (6*sizeof(unsigned))
191 #define HIGH_BITS (~((unsigned)(~0) >> TWELVE))
192
193 unsigned
hashjpw(const char * ss)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;
199
200 for (; *s; ++s) {
201 h = (h << TWELVE) + *s;
202 if ((g = h & HIGH_BITS))
203 h = (h ^ (g >> SEVENTYFIVE)) & ~HIGH_BITS;
204 }
205 return h;
206 }
207