Remove building with NOCRYPTO option
[minix3.git] / lib / libc / stdlib / hcreate.c
blobcab145d13b7f2486206abf5e2205c12b9733b585
1 /* $NetBSD: hcreate.c,v 1.10 2014/07/20 20:17:21 christos Exp $ */
3 /*
4 * Copyright (c) 2001 Christopher G. Demetriou
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 * <<Id: LICENSE,v 1.2 2000/06/14 15:57:33 cgd Exp>>
33 * hcreate() / hsearch() / hdestroy()
35 * SysV/XPG4 hash table functions.
37 * Implementation done based on NetBSD manual page and Solaris manual page,
38 * plus my own personal experience about how they're supposed to work.
40 * I tried to look at Knuth (as cited by the Solaris manual page), but
41 * nobody had a copy in the office, so...
44 #include <sys/cdefs.h>
45 #if defined(LIBC_SCCS) && !defined(lint)
46 __RCSID("$NetBSD: hcreate.c,v 1.10 2014/07/20 20:17:21 christos Exp $");
47 #endif /* LIBC_SCCS and not lint */
49 #if !defined(lint)
50 __COPYRIGHT("@(#) Copyright (c) 2001\
51 Christopher G. Demetriou. All rights reserved.");
52 #endif /* not lint */
54 #include "namespace.h"
55 #include <assert.h>
56 #include <errno.h>
57 #include <inttypes.h>
58 #include <search.h>
59 #include <stdlib.h>
60 #include <string.h>
61 #include <sys/queue.h>
64 * DO NOT MAKE THIS STRUCTURE LARGER THAN 32 BYTES (4 ptrs on 64-bit
65 * ptr machine) without adjusting MAX_BUCKETS_LG2 below.
67 struct internal_entry {
68 SLIST_ENTRY(internal_entry) link;
69 ENTRY ent;
71 SLIST_HEAD(internal_head, internal_entry);
73 #define MIN_BUCKETS_LG2 4
74 #define MIN_BUCKETS (1 << MIN_BUCKETS_LG2)
77 * max * sizeof internal_entry must fit into size_t.
78 * assumes internal_entry is <= 32 (2^5) bytes.
80 #define MAX_BUCKETS_LG2 (sizeof (size_t) * 8 - 1 - 5)
81 #define MAX_BUCKETS ((size_t)1 << MAX_BUCKETS_LG2)
83 /* Default hash function, from db/hash/hash_func.c */
84 extern u_int32_t (*__default_hash)(const void *, size_t);
86 static struct hsearch_data htable;
88 int
89 hcreate(size_t nel)
91 _DIAGASSERT(htable.table == NULL);
93 /* Make sure this isn't called when a table already exists. */
94 if (htable.table != NULL) {
95 errno = EINVAL;
96 return 0;
98 return hcreate_r(nel, &htable);
102 hcreate_r(size_t nel, struct hsearch_data *head)
104 struct internal_head *table;
105 size_t idx;
106 unsigned int p2;
107 void *p;
109 /* If nel is too small, make it min sized. */
110 if (nel < MIN_BUCKETS)
111 nel = MIN_BUCKETS;
113 /* If it's too large, cap it. */
114 if (nel > MAX_BUCKETS)
115 nel = MAX_BUCKETS;
117 /* If it's is not a power of two in size, round up. */
118 if ((nel & (nel - 1)) != 0) {
119 for (p2 = 0; nel != 0; p2++)
120 nel >>= 1;
121 _DIAGASSERT(p2 <= MAX_BUCKETS_LG2);
122 nel = 1 << p2;
125 /* Allocate the table. */
126 head->size = nel;
127 head->filled = 0;
128 p = malloc(nel * sizeof table[0]);
129 if (p == NULL) {
130 errno = ENOMEM;
131 return 0;
133 head->table = p;
134 table = p;
136 /* Initialize it. */
137 for (idx = 0; idx < nel; idx++)
138 SLIST_INIT(&table[idx]);
140 return 1;
143 void
144 hdestroy1(void (*freekey)(void *), void (*freedata)(void *))
146 _DIAGASSERT(htable.table != NULL);
147 hdestroy1_r(&htable, freekey, freedata);
150 void
151 hdestroy(void)
153 hdestroy1(NULL, NULL);
156 void
157 hdestroy1_r(struct hsearch_data *head, void (*freekey)(void *),
158 void (*freedata)(void *))
160 struct internal_entry *ie;
161 size_t idx;
162 void *p;
163 struct internal_head *table;
165 if (head == NULL)
166 return;
168 p = head->table;
169 head->table = NULL;
170 table = p;
172 for (idx = 0; idx < head->size; idx++) {
173 while (!SLIST_EMPTY(&table[idx])) {
174 ie = SLIST_FIRST(&table[idx]);
175 SLIST_REMOVE_HEAD(&table[idx], link);
176 if (freekey)
177 (*freekey)(ie->ent.key);
178 if (freedata)
179 (*freedata)(ie->ent.data);
180 free(ie);
183 free(table);
186 void
187 hdestroy_r(struct hsearch_data *head)
189 hdestroy1_r(head, NULL, NULL);
192 ENTRY *
193 hsearch(ENTRY item, ACTION action)
195 ENTRY *ep;
196 _DIAGASSERT(htable.table != NULL);
197 (void)hsearch_r(item, action, &ep, &htable);
198 return ep;
202 hsearch_r(ENTRY item, ACTION action, ENTRY **itemp, struct hsearch_data *head)
204 struct internal_head *table, *chain;
205 struct internal_entry *ie;
206 uint32_t hashval;
207 size_t len;
208 void *p;
210 _DIAGASSERT(item.key != NULL);
211 _DIAGASSERT(action == ENTER || action == FIND);
213 p = head->table;
214 table = p;
216 len = strlen(item.key);
217 hashval = (*__default_hash)(item.key, len);
219 chain = &table[hashval & (head->size - 1)];
220 ie = SLIST_FIRST(chain);
221 while (ie != NULL) {
222 if (strcmp(ie->ent.key, item.key) == 0)
223 break;
224 ie = SLIST_NEXT(ie, link);
227 if (ie != NULL) {
228 *itemp = &ie->ent;
229 return 1;
230 } else if (action == FIND) {
231 *itemp = NULL;
232 errno = ESRCH;
233 return 1;
236 ie = malloc(sizeof *ie);
237 if (ie == NULL)
238 return 0;
239 ie->ent.key = item.key;
240 ie->ent.data = item.data;
242 SLIST_INSERT_HEAD(chain, ie, link);
243 *itemp = &ie->ent;
244 head->filled++;
245 return 1;