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