usr/src/cmd/mandoc/compat_ohash.h

   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