1/*	$FreeBSD$	*/
2/*	$NetBSD: hash.h,v 1.1.1.1 1999/11/19 04:30:56 mrg Exp $	*/
3
4/*-
5 * SPDX-License-Identifier: BSD-4-Clause
6 *
7 * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
8 * Copyright (c) 1988, 1989 by Adam de Boor
9 * Copyright (c) 1989 by Berkeley Softworks
10 * All rights reserved.
11 *
12 * This code is derived from software contributed to Berkeley by
13 * Adam de Boor.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
18 * 1. Redistributions of source code must retain the above copyright
19 *    notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 *    notice, this list of conditions and the following disclaimer in the
22 *    documentation and/or other materials provided with the distribution.
23 * 3. All advertising materials mentioning features or use of this software
24 *    must display the following acknowledgement:
25 *	This product includes software developed by the University of
26 *	California, Berkeley and its contributors.
27 * 4. Neither the name of the University nor the names of its contributors
28 *    may be used to endorse or promote products derived from this software
29 *    without specific prior written permission.
30 *
31 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
32 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
33 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
34 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
35 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
39 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
40 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
41 * SUCH DAMAGE.
42 *
43 *	from: @(#)hash.h	8.1 (Berkeley) 6/6/93
44 */
45
46/* hash.h --
47 *
48 * 	This file contains definitions used by the hash module,
49 * 	which maintains hash tables.
50 */
51
52#ifndef	_HASH
53#define	_HASH
54
55/*
56 * The following defines one entry in the hash table.
57 */
58
59typedef struct Hash_Entry {
60	struct	Hash_Entry *next;	/* Used to link together all the
61					 * entries associated with the same
62					 * bucket. */
63	ClientData	clientData;	/* Arbitrary piece of data associated
64					 * with key. */
65	unsigned	namehash;	/* hash value of key */
66	char		name[1];	/* key string */
67} Hash_Entry;
68
69typedef struct Hash_Table {
70	struct	Hash_Entry **bucketPtr;
71				/* Pointers to Hash_Entry, one
72				 * for each bucket in the table. */
73	int 	size;		/* Actual size of array. */
74	int 	numEntries;	/* Number of entries in the table. */
75	int 	mask;		/* Used to select bits for hashing. */
76} Hash_Table;
77
78/*
79 * The following structure is used by the searching routines
80 * to record where we are in the search.
81 */
82
83typedef struct Hash_Search {
84	Hash_Table	*tablePtr;	/* Table being searched. */
85	int	 	nextIndex;	/* Next bucket to check (after
86					 * current). */
87	Hash_Entry 	*hashEntryPtr;	/* Next entry to check in current
88					 * bucket. */
89} Hash_Search;
90
91/*
92 * Macros.
93 */
94
95/*
96 * ClientData Hash_GetValue(h)
97 *     Hash_Entry *h;
98 */
99
100#define Hash_GetValue(h) ((h)->clientData)
101
102/*
103 * Hash_SetValue(h, val);
104 *     Hash_Entry *h;
105 *     char *val;
106 */
107
108#define Hash_SetValue(h, val) ((h)->clientData = (ClientData) (val))
109
110#ifdef ORDER
111/*
112 * Hash_GetKey(h);
113 *     Hash_Entry *h;
114 */
115
116#define Hash_GetKey(h) ((h)->name)
117#endif /* ORDER */
118
119/*
120 * Hash_Size(n) returns the number of words in an object of n bytes
121 */
122
123#define	Hash_Size(n)	(((n) + sizeof (int) - 1) / sizeof (int))
124
125void Hash_InitTable(Hash_Table *, int);
126void Hash_DeleteTable(Hash_Table *);
127Hash_Entry *Hash_FindEntry(Hash_Table *, char *);
128Hash_Entry *Hash_CreateEntry(Hash_Table *, char *, Boolean *);
129void Hash_DeleteEntry(Hash_Table *, Hash_Entry *);
130Hash_Entry *Hash_EnumFirst(Hash_Table *, Hash_Search *);
131Hash_Entry *Hash_EnumNext(Hash_Search *);
132
133#endif /* _HASH */
134