xref: /illumos-gate/usr/src/cmd/mandoc/compat_ohash.h (revision 371584c2)
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 */
27 struct 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 
35 struct _ohash_record;
36 
37 /* private structure. It's there just so you can do a sizeof */
38 struct 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 void ohash_init(struct ohash *, unsigned, struct ohash_info *);
53 void ohash_delete(struct ohash *);
54 
55 unsigned int ohash_lookup_interval(struct ohash *, const char *,
56 	    const char *, uint32_t);
57 unsigned int ohash_lookup_memory(struct ohash *, const char *,
58 	    size_t, uint32_t);
59 void *ohash_find(struct ohash *, unsigned int);
60 void *ohash_remove(struct ohash *, unsigned int);
61 void *ohash_insert(struct ohash *, unsigned int, void *);
62 void *ohash_first(struct ohash *, unsigned int *);
63 void *ohash_next(struct ohash *, unsigned int *);
64 unsigned int ohash_entries(struct ohash *);
65 
66 void *ohash_create_entry(struct ohash_info *, const char *, const char **);
67 uint32_t ohash_interval(const char *, const char **);
68 
69 unsigned int ohash_qlookupi(struct ohash *, const char *, const char **);
70 unsigned int ohash_qlookup(struct ohash *, const char *);
71 
72 #endif
73