xref: /freebsd/lib/libopenbsd/ohash.h (revision b3e7694832e81d7a904a10f525f8797b753bf0d3)
1*a36eca08SCraig Rodrigues /* $OpenBSD: src/lib/libutil/ohash.h,v 1.2 2014/06/02 18:52:03 deraadt Exp $ */
2*a36eca08SCraig Rodrigues 
3*a36eca08SCraig Rodrigues /* Copyright (c) 1999, 2004 Marc Espie <espie@openbsd.org>
4*a36eca08SCraig Rodrigues  *
5*a36eca08SCraig Rodrigues  * Permission to use, copy, modify, and distribute this software for any
6*a36eca08SCraig Rodrigues  * purpose with or without fee is hereby granted, provided that the above
7*a36eca08SCraig Rodrigues  * copyright notice and this permission notice appear in all copies.
8*a36eca08SCraig Rodrigues  *
9*a36eca08SCraig Rodrigues  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10*a36eca08SCraig Rodrigues  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11*a36eca08SCraig Rodrigues  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12*a36eca08SCraig Rodrigues  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13*a36eca08SCraig Rodrigues  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14*a36eca08SCraig Rodrigues  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15*a36eca08SCraig Rodrigues  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16*a36eca08SCraig Rodrigues  */
17*a36eca08SCraig Rodrigues 
18*a36eca08SCraig Rodrigues #ifndef OHASH_H
19*a36eca08SCraig Rodrigues #define OHASH_H
20*a36eca08SCraig Rodrigues 
21*a36eca08SCraig Rodrigues #include <stddef.h>
22*a36eca08SCraig Rodrigues 
23*a36eca08SCraig Rodrigues /* Open hashing support.
24*a36eca08SCraig Rodrigues  * Open hashing was chosen because it is much lighter than other hash
25*a36eca08SCraig Rodrigues  * techniques, and more efficient in most cases.
26*a36eca08SCraig Rodrigues  */
27*a36eca08SCraig Rodrigues 
28*a36eca08SCraig Rodrigues /* user-visible data structure */
29*a36eca08SCraig Rodrigues struct ohash_info {
30*a36eca08SCraig Rodrigues 	ptrdiff_t key_offset;
31*a36eca08SCraig Rodrigues 	void *data;	/* user data */
32*a36eca08SCraig Rodrigues 	void *(*calloc)(size_t, size_t, void *);
33*a36eca08SCraig Rodrigues 	void (*free)(void *, void *);
34*a36eca08SCraig Rodrigues 	void *(*alloc)(size_t, void *);
35*a36eca08SCraig Rodrigues };
36*a36eca08SCraig Rodrigues 
37*a36eca08SCraig Rodrigues struct _ohash_record;
38*a36eca08SCraig Rodrigues 
39*a36eca08SCraig Rodrigues /* private structure. It's there just so you can do a sizeof */
40*a36eca08SCraig Rodrigues struct ohash {
41*a36eca08SCraig Rodrigues 	struct _ohash_record 	*t;
42*a36eca08SCraig Rodrigues 	struct ohash_info 	info;
43*a36eca08SCraig Rodrigues 	unsigned int 		size;
44*a36eca08SCraig Rodrigues 	unsigned int 		total;
45*a36eca08SCraig Rodrigues 	unsigned int 		deleted;
46*a36eca08SCraig Rodrigues };
47*a36eca08SCraig Rodrigues 
48*a36eca08SCraig Rodrigues /* For this to be tweakable, we use small primitives, and leave part of the
49*a36eca08SCraig Rodrigues  * logic to the client application.  e.g., hashing is left to the client
50*a36eca08SCraig Rodrigues  * application.  We also provide a simple table entry lookup that yields
51*a36eca08SCraig Rodrigues  * a hashing table index (opaque) to be used in find/insert/remove.
52*a36eca08SCraig Rodrigues  * The keys are stored at a known position in the client data.
53*a36eca08SCraig Rodrigues  */
54*a36eca08SCraig Rodrigues __BEGIN_DECLS
55*a36eca08SCraig Rodrigues void ohash_init(struct ohash *, unsigned, struct ohash_info *);
56*a36eca08SCraig Rodrigues void ohash_delete(struct ohash *);
57*a36eca08SCraig Rodrigues 
58*a36eca08SCraig Rodrigues unsigned int ohash_lookup_interval(struct ohash *, const char *,
59*a36eca08SCraig Rodrigues 	    const char *, uint32_t);
60*a36eca08SCraig Rodrigues unsigned int ohash_lookup_memory(struct ohash *, const char *,
61*a36eca08SCraig Rodrigues 	    size_t, uint32_t);
62*a36eca08SCraig Rodrigues void *ohash_find(struct ohash *, unsigned int);
63*a36eca08SCraig Rodrigues void *ohash_remove(struct ohash *, unsigned int);
64*a36eca08SCraig Rodrigues void *ohash_insert(struct ohash *, unsigned int, void *);
65*a36eca08SCraig Rodrigues void *ohash_first(struct ohash *, unsigned int *);
66*a36eca08SCraig Rodrigues void *ohash_next(struct ohash *, unsigned int *);
67*a36eca08SCraig Rodrigues unsigned int ohash_entries(struct ohash *);
68*a36eca08SCraig Rodrigues 
69*a36eca08SCraig Rodrigues void *ohash_create_entry(struct ohash_info *, const char *, const char **);
70*a36eca08SCraig Rodrigues uint32_t ohash_interval(const char *, const char **);
71*a36eca08SCraig Rodrigues 
72*a36eca08SCraig Rodrigues unsigned int ohash_qlookupi(struct ohash *, const char *, const char **);
73*a36eca08SCraig Rodrigues unsigned int ohash_qlookup(struct ohash *, const char *);
74*a36eca08SCraig Rodrigues __END_DECLS
75*a36eca08SCraig Rodrigues #endif
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