cwm/hash.h

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2007-04-27 21:58:48 +04:00
/*
* hash.h - generic hash template, akin to queue.h & tree.h
*
* Copyright (c) 2005 Marius Eriksen <marius@monkey.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 _HASH_H_ /* Possibly this is too generic. */
#define _HASH_H_
#include <sys/tree.h>
#define HASH_ENTRY SPLAY_ENTRY
#define HASH_HEAD(name, type, nbuckets) \
SPLAY_HEAD(name##_HASH_TREE, type); \
struct name { \
struct name##_HASH_TREE buckets[nbuckets]; \
unsigned int (*hashfn)(struct type *elm); \
};
#define HASH_NBUCKETS(head) \
(sizeof((head)->buckets)/sizeof((head)->buckets[0]))
#define HASH_INIT(head, fn) do { \
int i; \
for (i = 0; i < HASH_NBUCKETS(head); i++) { \
SPLAY_INIT(&(head)->buckets[i]); \
} \
(head)->hashfn = fn; \
} while (0)
#define HASH_PROTOTYPE(name, type, field, cmp) \
SPLAY_PROTOTYPE(name##_HASH_TREE, type, field, cmp) \
struct type *name##_HASH_TREE_FIND(struct name *head, struct type *find); \
void name##_HASH_TREE_INSERT(struct name *head, struct type *insert);
#define HASH_GENERATE(name, type, field, cmp) \
SPLAY_GENERATE(name##_HASH_TREE, type, field, cmp) \
struct type *name##_HASH_TREE_FIND(struct name *head, struct type *find) \
{ \
struct name##_HASH_TREE *bucket = \
&head->buckets[(*head->hashfn)(find) % HASH_NBUCKETS(head)]; \
return SPLAY_FIND(name##_HASH_TREE, bucket, find); \
} \
void name##_HASH_TREE_INSERT(struct name *head, struct type *insert) \
{ \
struct name##_HASH_TREE *bucket = \
&head->buckets[(*head->hashfn)(insert) % HASH_NBUCKETS(head)]; \
\
SPLAY_INSERT(name##_HASH_TREE, bucket, insert); \
}
#define HASH_FIND(name, head, find) name##_HASH_TREE_FIND((head), (find))
#define HASH_INSERT(name, head, insert) name##_HASH_TREE_INSERT((head), (insert))
#endif /* _HASH_H_ */