sbin/rcorder/hash.h

   1 /*      $NetBSD: hash.h,v 1.2 2002/06/30 14:17:45 lukem Exp $   */
   2
   3 /*
   4  * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Adam de Boor.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  *      from: @(#)hash.h        8.1 (Berkeley) 6/6/93
  35  */
  36
  37 /*
  38  * Copyright (c) 1988, 1989 by Adam de Boor
  39  * Copyright (c) 1989 by Berkeley Softworks
  40  * All rights reserved.
  41  *
  42  * This code is derived from software contributed to Berkeley by
  43  * Adam de Boor.
  44  *
  45  * Redistribution and use in source and binary forms, with or without
  46  * modification, are permitted provided that the following conditions
  47  * are met:
  48  * 1. Redistributions of source code must retain the above copyright
  49  *    notice, this list of conditions and the following disclaimer.
  50  * 2. Redistributions in binary form must reproduce the above copyright
  51  *    notice, this list of conditions and the following disclaimer in the
  52  *    documentation and/or other materials provided with the distribution.
  53  * 3. All advertising materials mentioning features or use of this software
  54  *    must display the following acknowledgement:
  55  *      This product includes software developed by the University of
  56  *      California, Berkeley and its contributors.
  57  * 4. Neither the name of the University nor the names of its contributors
  58  *    may be used to endorse or promote products derived from this software
  59  *    without specific prior written permission.
  60  *
  61  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  62  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  63  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  64  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  65  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  66  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  67  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  68  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  69  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  70  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  71  * SUCH DAMAGE.
  72  *
  73  *      from: @(#)hash.h        8.1 (Berkeley) 6/6/93
  74  */
  75
  76 /* hash.h --
  77  *
  78  *      This file contains definitions used by the hash module,
  79  *      which maintains hash tables.
  80  */
  81
  82 #ifndef _HASH
  83 #define _HASH
  84
  85 /*
  86  * The following defines one entry in the hash table.
  87  */
  88
  89 typedef struct Hash_Entry {
  90         struct  Hash_Entry *next;       /* Used to link together all the
  91                                          * entries associated with the same
  92                                          * bucket. */
  93         void            *clientData;    /* Arbitrary piece of data associated
  94                                          * with key. */
  95         unsigned        namehash;       /* hash value of key */
  96         char            name[1];        /* key string */
  97 } Hash_Entry;
  98
  99 typedef struct Hash_Table {
 100         struct  Hash_Entry **bucketPtr;
 101                                 /* Pointers to Hash_Entry, one
 102                                  * for each bucket in the table. */
 103         int     size;           /* Actual size of array. */
 104         int     numEntries;     /* Number of entries in the table. */
 105         int     mask;           /* Used to select bits for hashing. */
 106 } Hash_Table;
 107
 108 /*
 109  * The following structure is used by the searching routines
 110  * to record where we are in the search.
 111  */
 112
 113 typedef struct Hash_Search {
 114         Hash_Table      *tablePtr;      /* Table being searched. */
 115         int             nextIndex;      /* Next bucket to check (after
 116                                          * current). */
 117         Hash_Entry      *hashEntryPtr;  /* Next entry to check in current
 118                                          * bucket. */
 119 } Hash_Search;
 120
 121 /*
 122  * Macros.
 123  */
 124
 125 /*
 126  * void *Hash_GetValue(h)
 127  *     Hash_Entry *h;
 128  */
 129
 130 #define Hash_GetValue(h) ((h)->clientData)
 131
 132 /*
 133  * Hash_SetValue(h, val);
 134  *     Hash_Entry *h;
 135  *     char *val;
 136  */
 137
 138 #define Hash_SetValue(h, val) ((h)->clientData = (void *) (val))
 139
 140 /*
 141  * Hash_GetKey(h);
 142  *     Hash_Entry *h;
 143  */
 144
 145 #define Hash_GetKey(h) ((h)->name)
 146
 147 /*
 148  * Hash_Size(n) returns the number of words in an object of n bytes
 149  */
 150
 151 #define Hash_Size(n)    (((n) + sizeof (int) - 1) / sizeof (int))
 152
 153 void Hash_InitTable(Hash_Table *, int);
 154 void Hash_DeleteTable(Hash_Table *);
 155 Hash_Entry *Hash_FindEntry(Hash_Table *, char *);
 156 Hash_Entry *Hash_CreateEntry(Hash_Table *, char *, int *);
 157 void Hash_DeleteEntry(Hash_Table *, Hash_Entry *);
 158 Hash_Entry *Hash_EnumFirst(Hash_Table *, Hash_Search *);
 159 Hash_Entry *Hash_EnumNext(Hash_Search *);
 160
 161 #endif /* _HASH */