1 #ifndef OHASH_H 2 #define OHASH_H 3 /* $OpenBSD: ohash.h,v 1.8 2005/12/29 18:54:47 jaredy Exp $ */ 4 /* ex:ts=8 sw=4: 5 */ 6 7 /* Copyright (c) 1999, 2004 Marc Espie <espie@openbsd.org> 8 * 9 * Permission to use, copy, modify, and distribute this software for any 10 * purpose with or without fee is hereby granted, provided that the above 11 * copyright notice and this permission notice appear in all copies. 12 * 13 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 14 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 15 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 16 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 17 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 18 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 19 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 20 */ 21 22 /* Open hashing support. 23 * Open hashing was chosen because it is much lighter than other hash 24 * techniques, and more efficient in most cases. 25 */ 26 27 struct ohash_info { 28 ptrdiff_t key_offset; 29 void *data; /* user data */ 30 void *(*halloc)(size_t, void *); 31 void (*hfree)(void *, size_t, void *); 32 void *(*alloc)(size_t, void *); 33 }; 34 35 struct _ohash_record; 36 37 struct ohash { 38 struct _ohash_record *t; 39 struct ohash_info info; 40 unsigned int size; 41 unsigned int total; 42 unsigned int deleted; 43 }; 44 45 /* For this to be tweakable, we use small primitives, and leave part of the 46 * logic to the client application. e.g., hashing is left to the client 47 * application. We also provide a simple table entry lookup that yields 48 * a hashing table index (opaque) to be used in find/insert/remove. 49 * The keys are stored at a known position in the client data. 50 */ 51 __BEGIN_DECLS 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 *, u_int32_t); 57 unsigned int ohash_lookup_memory(struct ohash *, const char *, 58 size_t, u_int32_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 u_int32_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 __END_DECLS 72 #endif 73 74