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