1/*	$NetBSD: hash.h,v 1.1.1.1 1999/11/19 04:30:56 mrg Exp $	*/
2
3/*-
4 * SPDX-License-Identifier: BSD-4-Clause
5 *
6 * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
7 * Copyright (c) 1988, 1989 by Adam de Boor
8 * Copyright (c) 1989 by Berkeley Softworks
9 * All rights reserved.
10 *
11 * This code is derived from software contributed to Berkeley by
12 * Adam de Boor.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 * 1. Redistributions of source code must retain the above copyright
18 *    notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 *    notice, this list of conditions and the following disclaimer in the
21 *    documentation and/or other materials provided with the distribution.
22 * 3. All advertising materials mentioning features or use of this software
23 *    must display the following acknowledgement:
24 *	This product includes software developed by the University of
25 *	California, Berkeley and its contributors.
26 * 4. Neither the name of the University nor the names of its contributors
27 *    may be used to endorse or promote products derived from this software
28 *    without specific prior written permission.
29 *
30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40 * SUCH DAMAGE.
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
56typedef 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
66typedef 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
80typedef 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
122void Hash_InitTable(Hash_Table *, int);
123void Hash_DeleteTable(Hash_Table *);
124Hash_Entry *Hash_FindEntry(Hash_Table *, char *);
125Hash_Entry *Hash_CreateEntry(Hash_Table *, char *, Boolean *);
126void Hash_DeleteEntry(Hash_Table *, Hash_Entry *);
127Hash_Entry *Hash_EnumFirst(Hash_Table *, Hash_Search *);
128Hash_Entry *Hash_EnumNext(Hash_Search *);
129
130#endif /* _HASH */
131