/* $OpenBSD: ohash.h,v 1.2 2014/06/02 18:52:03 deraadt Exp $ */
/* Copyright (c) 1999, 2004 Marc Espie <espie@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifndef OHASH_H
#define OHASH_H
/* Open hashing support.
* Open hashing was chosen because it is much lighter than other hash
* techniques, and more efficient in most cases.
*/
/* user-visible data structure */
struct ohash_info {
ptrdiff_t key_offset;
void *data; /* user data */
void *(*calloc)(size_t, size_t, void *);
void (*free)(void *, void *);
void *(*alloc)(size_t, void *);
};
struct _ohash_record;
/* private structure. It's there just so you can do a sizeof */
struct ohash {
struct _ohash_record *t;
struct ohash_info info;
unsigned int size;
unsigned int total;
unsigned int deleted;
};
/* For this to be tweakable, we use small primitives, and leave part of the
* logic to the client application. e.g., hashing is left to the client
* application. We also provide a simple table entry lookup that yields
* a hashing table index (opaque) to be used in find/insert/remove.
* The keys are stored at a known position in the client data.
*/
__BEGIN_DECLS
void ohash_init(struct ohash *, unsigned, struct ohash_info *);
void ohash_delete(struct ohash *);
unsigned int ohash_lookup_interval(struct ohash *, const char *,
const char *, uint32_t);
unsigned int ohash_lookup_memory(struct ohash *, const char *,
size_t, uint32_t)
__attribute__ ((__bounded__(__string__,2,3)));
void *ohash_find(struct ohash *, unsigned int);
void *ohash_remove(struct ohash *, unsigned int);
void *ohash_insert(struct ohash *, unsigned int, void *);
void *ohash_first(struct ohash *, unsigned int *);
void *ohash_next(struct ohash *, unsigned int *);
unsigned int ohash_entries(struct ohash *);
void *ohash_create_entry(struct ohash_info *, const char *, const char **);
uint32_t ohash_interval(const char *, const char **);
unsigned int ohash_qlookupi(struct ohash *, const char *, const char **);
unsigned int ohash_qlookup(struct ohash *, const char *);
__END_DECLS
#endif
