sbin/rcorder/hash.h

   1 /*
   2  * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
   3  * Copyright (c) 1988, 1989 by Adam de Boor
   4  * Copyright (c) 1989 by Berkeley Softworks
   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. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *      This product includes software developed by the University of
  21  *      California, Berkeley and its contributors.
  22  * 4. Neither the name of the University nor the names of its contributors
  23  *    may be used to endorse or promote products derived from this software
  24  *    without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  *
  38  *      from: @(#)hash.h        8.1 (Berkeley) 6/6/93
  39  *      $NetBSD: hash.h,v 1.1.1.1 1999/11/19 04:30:56 mrg Exp $
  40  *      $DragonFly: src/sbin/rcorder/hash.h,v 1.2 2003/11/01 17:16:01 drhodus Exp $
  41  */
  42
  43 /* hash.h --
  44  *
  45  *      This file contains definitions used by the hash module,
  46  *      which maintains hash tables.
  47  */
  48
  49 #ifndef _HASH
  50 #define _HASH
  51
  52 /*
  53  * The following defines one entry in the hash table.
  54  */
  55
  56 typedef struct Hash_Entry {
  57         struct  Hash_Entry *next;       /* Used to link together all the
  58                                          * entries associated with the same
  59                                          * bucket. */
  60         ClientData      clientData;     /* Arbitrary piece of data associated
  61                                          * with key. */
  62         unsigned        namehash;       /* hash value of key */
  63         char            name[1];        /* key string */
  64 } Hash_Entry;
  65
  66 typedef struct Hash_Table {
  67         struct  Hash_Entry **bucketPtr;
  68                                 /* Pointers to Hash_Entry, one
  69                                  * for each bucket in the table. */
  70         int     size;           /* Actual size of array. */
  71         int     numEntries;     /* Number of entries in the table. */
  72         int     mask;           /* Used to select bits for hashing. */
  73 } Hash_Table;
  74
  75 /*
  76  * The following structure is used by the searching routines
  77  * to record where we are in the search.
  78  */
  79
  80 typedef struct Hash_Search {
  81         Hash_Table      *tablePtr;      /* Table being searched. */
  82         int             nextIndex;      /* Next bucket to check (after
  83                                          * current). */
  84         Hash_Entry      *hashEntryPtr;  /* Next entry to check in current
  85                                          * bucket. */
  86 } Hash_Search;
  87
  88 /*
  89  * Macros.
  90  */
  91
  92 /*
  93  * ClientData Hash_GetValue(h)
  94  *     Hash_Entry *h;
  95  */
  96
  97 #define Hash_GetValue(h) ((h)->clientData)
  98
  99 /*
 100  * Hash_SetValue(h, val);
 101  *     Hash_Entry *h;
 102  *     char *val;
 103  */
 104
 105 #define Hash_SetValue(h, val) ((h)->clientData = (ClientData) (val))
 106
 107 #ifdef ORDER
 108 /*
 109  * Hash_GetKey(h);
 110  *     Hash_Entry *h;
 111  */
 112
 113 #define Hash_GetKey(h) ((h)->name)
 114 #endif /* ORDER */
 115
 116 /*
 117  * Hash_Size(n) returns the number of words in an object of n bytes
 118  */
 119
 120 #define Hash_Size(n)    (((n) + sizeof (int) - 1) / sizeof (int))
 121
 122 void Hash_InitTable(Hash_Table *, int);
 123 void Hash_DeleteTable(Hash_Table *);
 124 Hash_Entry *Hash_FindEntry(Hash_Table *, char *);
 125 Hash_Entry *Hash_CreateEntry(Hash_Table *, char *, Boolean *);
 126 void Hash_DeleteEntry(Hash_Table *, Hash_Entry *);
 127 Hash_Entry *Hash_EnumFirst(Hash_Table *, Hash_Search *);
 128 Hash_Entry *Hash_EnumNext(Hash_Search *);
 129
 130 #endif /* _HASH */