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 * $FreeBSD: releng/10.3/usr.bin/m4/lib/ohash.h 228063 2011-11-28 13:32:39Z bapt $
22 */
23
24/* Open hashing support.
25 * Open hashing was chosen because it is much lighter than other hash
26 * techniques, and more efficient in most cases.
27 */
28
29struct ohash_info {
30	ptrdiff_t key_offset;
31	void *data;	/* user data */
32	void *(*halloc)(size_t, void *);
33	void (*hfree)(void *, size_t, void *);
34	void *(*alloc)(size_t, void *);
35};
36
37struct _ohash_record;
38
39struct ohash {
40	struct _ohash_record 	*t;
41	struct ohash_info 	info;
42	unsigned int 		size;
43	unsigned int 		total;
44	unsigned int 		deleted;
45};
46
47/* For this to be tweakable, we use small primitives, and leave part of the
48 * logic to the client application.  e.g., hashing is left to the client
49 * application.  We also provide a simple table entry lookup that yields
50 * a hashing table index (opaque) to be used in find/insert/remove.
51 * The keys are stored at a known position in the client data.
52 */
53__BEGIN_DECLS
54void ohash_init(struct ohash *, unsigned, struct ohash_info *);
55void ohash_delete(struct ohash *);
56
57unsigned int ohash_lookup_interval(struct ohash *, const char *,
58	    const char *, u_int32_t);
59unsigned int ohash_lookup_memory(struct ohash *, const char *,
60	    size_t, u_int32_t);
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 **);
69u_int32_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
75
76