xref: /netbsd-src/usr.bin/make/hash.h (revision ae9172d6cd9432a6a1a56760d86b32c57a66c39c)
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	5.4 (Berkeley) 12/28/90
39  *	$Id: hash.h,v 1.3 1994/03/05 00:34:46 cgd Exp $
40  */
41 
42 /* hash.h --
43  *
44  * 	This file contains definitions used by the hash module,
45  * 	which maintains hash tables.
46  */
47 
48 #ifndef	_HASH
49 #define	_HASH
50 
51 /*
52  * The following defines one entry in the hash table.
53  */
54 
55 typedef struct Hash_Entry {
56     struct Hash_Entry *next;		/* Used to link together all the
57     					 * entries associated with the same
58 					 * bucket. */
59     ClientData	      clientData;	/* Arbitrary piece of data associated
60     					 * with key. */
61     unsigned	      namehash;		/* hash value of key */
62     char	      name[1];		/* key string */
63 } Hash_Entry;
64 
65 typedef struct Hash_Table {
66     struct Hash_Entry **bucketPtr;/* Pointers to Hash_Entry, one
67     				 * for each bucket in the table. */
68     int 	size;		/* Actual size of array. */
69     int 	numEntries;	/* Number of entries in the table. */
70     int 	mask;		/* Used to select bits for hashing. */
71 } Hash_Table;
72 
73 /*
74  * The following structure is used by the searching routines
75  * to record where we are in the search.
76  */
77 
78 typedef struct Hash_Search {
79     Hash_Table  *tablePtr;	/* Table being searched. */
80     int 	nextIndex;	/* Next bucket to check (after current). */
81     Hash_Entry 	*hashEntryPtr;	/* Next entry to check in current bucket. */
82 } Hash_Search;
83 
84 /*
85  * Macros.
86  */
87 
88 /*
89  * ClientData Hash_GetValue(h)
90  *     Hash_Entry *h;
91  */
92 
93 #define Hash_GetValue(h) ((h)->clientData)
94 
95 /*
96  * Hash_SetValue(h, val);
97  *     Hash_Entry *h;
98  *     char *val;
99  */
100 
101 #define Hash_SetValue(h, val) ((h)->clientData = (ClientData) (val))
102 
103 /*
104  * Hash_Size(n) returns the number of words in an object of n bytes
105  */
106 
107 #define	Hash_Size(n)	(((n) + sizeof (int) - 1) / sizeof (int))
108 
109 void Hash_InitTable __P((Hash_Table *, int));
110 void Hash_DeleteTable __P((Hash_Table *));
111 Hash_Entry *Hash_FindEntry __P((Hash_Table *, char *));
112 Hash_Entry *Hash_CreateEntry __P((Hash_Table *, char *, Boolean *));
113 void Hash_DeleteEntry __P((Hash_Table *, Hash_Entry *));
114 Hash_Entry *Hash_EnumFirst __P((Hash_Table *, Hash_Search *));
115 Hash_Entry *Hash_EnumNext __P((Hash_Search *));
116 
117 #endif /* _HASH */
118