1/* $OpenBSD: ohash.h,v 1.2 2014/06/02 18:52:03 deraadt Exp $ */
2
3/* Copyright (c) 1999, 2004 Marc Espie <espie@openbsd.org>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18#ifndef OHASH_H
19#define OHASH_H
20
21/* Open hashing support.
22 * Open hashing was chosen because it is much lighter than other hash
23 * techniques, and more efficient in most cases.
24 */
25
26/* user-visible data structure */
27struct ohash_info {
28 ptrdiff_t key_offset;
29 void *data; /* user data */
30 void *(*calloc)(size_t, size_t, void *);
31 void (*free)(void *, void *);
32 void *(*alloc)(size_t, void *);
33};
34
35struct _ohash_record;
36
37/* private structure. It's there just so you can do a sizeof */
38struct ohash {
39 struct _ohash_record *t;
40 struct ohash_info info;
41 unsigned int size;
42 unsigned int total;
43 unsigned int deleted;
44};
45
46/* For this to be tweakable, we use small primitives, and leave part of the
47 * logic to the client application. e.g., hashing is left to the client
48 * application. We also provide a simple table entry lookup that yields
49 * a hashing table index (opaque) to be used in find/insert/remove.
50 * The keys are stored at a known position in the client data.
51 */
52__BEGIN_DECLS
53void ohash_init(struct ohash *, unsigned, struct ohash_info *);
54void ohash_delete(struct ohash *);
55
56unsigned int ohash_lookup_interval(struct ohash *, const char *,
57 const char *, uint32_t);
58unsigned int ohash_lookup_memory(struct ohash *, const char *,
59 size_t, uint32_t)
60 __attribute__ ((__bounded__(__string__,2,3)));
61void *ohash_find(struct ohash *, unsigned int);
62void *ohash_remove(struct ohash *, unsigned int);
63void *ohash_insert(struct ohash *, unsigned int, void *);
64void *ohash_first(struct ohash *, unsigned int *);
65void *ohash_next(struct ohash *, unsigned int *);
66unsigned int ohash_entries(struct ohash *);
67
68void *ohash_create_entry(struct ohash_info *, const char *, const char **);
69uint32_t ohash_interval(const char *, const char **);
70
71unsigned int ohash_qlookupi(struct ohash *, const char *, const char **);
72unsigned int ohash_qlookup(struct ohash *, const char *);
73__END_DECLS
74#endif