1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26#ifndef _SYS_MODHASH_IMPL_H
27#define	_SYS_MODHASH_IMPL_H
28
29#pragma ident	"%Z%%M%	%I%	%E% SMI"
30
31/*
32 * Internal details for the kernel's generic hash implementation.
33 */
34
35#ifdef __cplusplus
36extern "C" {
37#endif
38
39#ifdef _KERNEL
40
41#include <sys/ksynch.h>
42#include <sys/modhash.h>
43
44struct mod_hash_entry {
45	mod_hash_key_t mhe_key;			/* stored hash key	*/
46	mod_hash_val_t mhe_val;			/* stored hash value	*/
47	struct mod_hash_entry *mhe_next;	/* next item in chain	*/
48};
49
50struct mod_hash_stat {
51	ulong_t mhs_hit;	/* tried a 'find' and it succeeded */
52	ulong_t mhs_miss;	/* tried a 'find' but it failed */
53	ulong_t mhs_coll;	/* occur when insert fails because of dup's */
54	ulong_t mhs_nelems;	/* total number of stored key/value pairs */
55	ulong_t mhs_nomem;	/* number of times kmem_alloc failed */
56};
57
58struct mod_hash {
59	krwlock_t	mh_contents;	/* lock protecting contents */
60	char		*mh_name;	/* hash name */
61	int		mh_sleep;	/* kmem_alloc flag */
62	size_t		mh_nchains;	/* # of elements in mh_entries */
63
64	/* key and val destructor */
65	void    (*mh_kdtor)(mod_hash_key_t);
66	void    (*mh_vdtor)(mod_hash_val_t);
67
68	/* key comparator */
69	int	(*mh_keycmp)(mod_hash_key_t, mod_hash_key_t);
70
71	/* hash algorithm, and algorithm-private data */
72	uint_t  (*mh_hashalg)(void *, mod_hash_key_t);
73	void    *mh_hashalg_data;
74
75	struct mod_hash	*mh_next;	/* next hash in list */
76
77	struct mod_hash_stat mh_stat;
78
79	struct mod_hash_entry *mh_entries[1];
80};
81
82/*
83 * MH_SIZE()
84 * 	Compute the size of a mod_hash_t, in bytes, given the number of
85 * 	elements it contains.
86 */
87#define	MH_SIZE(n) \
88	(sizeof (mod_hash_t) + ((n) - 1) * (sizeof (struct mod_hash_entry *)))
89
90/*
91 * Module initialization; called once.
92 */
93void mod_hash_init(void);
94
95/*
96 * Internal routines.  Use directly with care.
97 */
98uint_t i_mod_hash(mod_hash_t *, mod_hash_key_t);
99int i_mod_hash_insert_nosync(mod_hash_t *, mod_hash_key_t, mod_hash_val_t,
100    mod_hash_hndl_t);
101int i_mod_hash_remove_nosync(mod_hash_t *, mod_hash_key_t, mod_hash_val_t *);
102int i_mod_hash_find_nosync(mod_hash_t *, mod_hash_key_t, mod_hash_val_t *);
103void i_mod_hash_walk_nosync(mod_hash_t *, uint_t (*)(mod_hash_key_t,
104    mod_hash_val_t *, void *), void *);
105void i_mod_hash_clear_nosync(mod_hash_t *hash);
106
107#endif /* _KERNEL */
108
109#ifdef __cplusplus
110}
111#endif
112
113#endif /* _SYS_MODHASH_IMPL_H */
114