usr/src/uts/common/sys/modhash_impl.h

   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
  36 extern "C" {
  37 #endif
  38
  39 #ifdef _KERNEL
  40
  41 #include <sys/ksynch.h>
  42 #include <sys/modhash.h>
  43
  44 struct 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
  50 struct 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
  58 struct 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  */
  93 void mod_hash_init(void);
  94
  95 /*
  96  * Internal routines.  Use directly with care.
  97  */
  98 uint_t i_mod_hash(mod_hash_t *, mod_hash_key_t);
  99 int i_mod_hash_insert_nosync(mod_hash_t *, mod_hash_key_t, mod_hash_val_t,
 100     mod_hash_hndl_t);
 101 int i_mod_hash_remove_nosync(mod_hash_t *, mod_hash_key_t, mod_hash_val_t *);
 102 int i_mod_hash_find_nosync(mod_hash_t *, mod_hash_key_t, mod_hash_val_t *);
 103 void i_mod_hash_walk_nosync(mod_hash_t *, uint_t (*)(mod_hash_key_t,
 104     mod_hash_val_t *, void *), void *);
 105 void 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 */