1#ifndef OHASH_H
2#define OHASH_H
3/* $OpenBSD: ohash.h,v 1.8 2005/12/29 18:54:47 jaredy Exp $ */
4/* ex:ts=8 sw=4:
5 */
6
7/* Copyright (c) 1999, 2004 Marc Espie <espie@openbsd.org>
8 *
9 * Permission to use, copy, modify, and distribute this software for any
10 * purpose with or without fee is hereby granted, provided that the above
11 * copyright notice and this permission notice appear in all copies.
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
14 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
15 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
16 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
17 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
18 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
19 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20 */
21
22/* Open hashing support.
23 * Open hashing was chosen because it is much lighter than other hash
24 * techniques, and more efficient in most cases.
25 */
26
27struct ohash_info {
28	ptrdiff_t key_offset;
29	void *data;	/* user data */
30	void *(*halloc)(size_t, void *);
31	void (*hfree)(void *, size_t, void *);
32	void *(*alloc)(size_t, void *);
33};
34
35struct _ohash_record;
36
37struct ohash {
38	struct _ohash_record 	*t;
39	struct ohash_info 	info;
40	unsigned int 		size;
41	unsigned int 		total;
42	unsigned int 		deleted;
43};
44
45/* For this to be tweakable, we use small primitives, and leave part of the
46 * logic to the client application.  e.g., hashing is left to the client
47 * application.  We also provide a simple table entry lookup that yields
48 * a hashing table index (opaque) to be used in find/insert/remove.
49 * The keys are stored at a known position in the client data.
50 */
51__BEGIN_DECLS
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 *, u_int32_t);
57unsigned int ohash_lookup_memory(struct ohash *, const char *,
58	    size_t, u_int32_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 **);
67u_int32_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__END_DECLS
72#endif
73
74