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