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
89typedef 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
99typedef 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
113typedef 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
153void Hash_InitTable(Hash_Table *, int);
154void Hash_DeleteTable(Hash_Table *);
155Hash_Entry *Hash_FindEntry(Hash_Table *, char *);
156Hash_Entry *Hash_CreateEntry(Hash_Table *, char *, int *);
157void Hash_DeleteEntry(Hash_Table *, Hash_Entry *);
158Hash_Entry *Hash_EnumFirst(Hash_Table *, Hash_Search *);
159Hash_Entry *Hash_EnumNext(Hash_Search *);
160
161#endif /* _HASH */
162