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 */
52void ohash_init(struct ohash *, unsigned, struct ohash_info *);
53void ohash_delete(struct ohash *);
54
55unsigned int ohash_lookup_interval(struct ohash *, const char *,
56	    const char *, uint32_t);
57unsigned int ohash_lookup_memory(struct ohash *, const char *,
58	    size_t, uint32_t);
59void *ohash_find(struct ohash *, unsigned int);
60void *ohash_remove(struct ohash *, unsigned int);
61void *ohash_insert(struct ohash *, unsigned int, void *);
62void *ohash_first(struct ohash *, unsigned int *);
63void *ohash_next(struct ohash *, unsigned int *);
64unsigned int ohash_entries(struct ohash *);
65
66void *ohash_create_entry(struct ohash_info *, const char *, const char **);
67uint32_t ohash_interval(const char *, const char **);
68
69unsigned int ohash_qlookupi(struct ohash *, const char *, const char **);
70unsigned int ohash_qlookup(struct ohash *, const char *);
71
72#endif
73