xref: /dragonfly/sbin/rcorder/hash.h (revision 9dbf638f)
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 1.1 2003/07/24 06:35:38 dillon 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 __P((Hash_Table *, int));
123 void Hash_DeleteTable __P((Hash_Table *));
124 Hash_Entry *Hash_FindEntry __P((Hash_Table *, char *));
125 Hash_Entry *Hash_CreateEntry __P((Hash_Table *, char *, Boolean *));
126 void Hash_DeleteEntry __P((Hash_Table *, Hash_Entry *));
127 Hash_Entry *Hash_EnumFirst __P((Hash_Table *, Hash_Search *));
128 Hash_Entry *Hash_EnumNext __P((Hash_Search *));
129 
130 #endif /* _HASH */
131