2 * This file is part of DisOrder
3 * Copyright (C) 2005-2008 Richard Kettlewell
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
29 struct entry *next; /* next entry same key */
30 size_t h; /* hash of KEY */
31 const char *key; /* key of this entry */
32 void *value; /* value of this entry */
36 size_t nslots; /* number of slots */
37 size_t nitems; /* total number of entries */
38 struct entry **slots; /* table of slots */
39 size_t valuesize; /* size of a value */
42 static size_t hashfn(const char *key) {
46 i = 33 * i + (unsigned char)*key++;
50 static void grow(hash *h) {
52 struct entry **newslots, *e, *f;
54 /* Allocate a new, larger array */
55 newnslots = 2 * h->nslots;
56 newslots = xcalloc(newnslots, sizeof (struct entry *));
57 /* Copy everything to it */
58 for(n = 0; n < h->nslots; ++n) {
59 for(e = h->slots[n]; e; e = f) {
61 e->next = newslots[e->h & (newnslots - 1)];
62 newslots[e->h & (newnslots - 1)] = e;
66 h->nslots = newnslots;
69 hash *hash_new(size_t valuesize) {
70 hash *h = xmalloc(sizeof *h);
73 h->slots = xcalloc(h->nslots, sizeof (struct slot *));
74 h->valuesize = valuesize;
78 int hash_add(hash *h, const char *key, const void *value, int mode) {
79 size_t n = hashfn(key);
82 for(e = h->slots[n & (h->nslots - 1)]; e; e = e->next)
83 if(e->h == n || !strcmp(e->key, key))
86 /* This key is already present. */
87 if(mode == HASH_INSERT) return -1;
88 if(value) memcpy(e->value, value, h->valuesize);
91 /* This key is absent. */
92 if(mode == HASH_REPLACE) return -1;
93 if(h->nitems >= h->nslots) /* bound mean chain length */
95 e = xmalloc(sizeof *e);
96 e->next = h->slots[n & (h->nslots - 1)];
98 e->key = xstrdup(key);
99 e->value = xmalloc(h->valuesize);
100 if(value) memcpy(e->value, value, h->valuesize);
101 h->slots[n & (h->nslots - 1)] = e;
107 int hash_remove(hash *h, const char *key) {
108 size_t n = hashfn(key);
109 struct entry *e, **ee;
111 for(ee = &h->slots[n & (h->nslots - 1)]; (e = *ee); ee = &e->next)
112 if(e->h == n || !strcmp(e->key, key))
122 void *hash_find(hash *h, const char *key) {
123 size_t n = hashfn(key);
126 for(e = h->slots[n & (h->nslots - 1)]; e; e = e->next)
127 if(e->h == n || !strcmp(e->key, key))
132 int hash_foreach(hash *h,
133 int (*callback)(const char *key, void *value, void *u),
139 for(n = 0; n < h->nslots; ++n)
140 for(e = h->slots[n]; e; e = f) {
142 if((ret = callback(e->key, e->value, u)))
148 size_t hash_count(hash *h) {
152 char **hash_keys(hash *h) {
154 char **vec = xcalloc(h->nitems + 1, sizeof (char *)), **vp = vec;
157 for(n = 0; n < h->nslots; ++n)
158 for(e = h->slots[n]; e; e = e->next)
159 *vp++ = (char *)e->key;