hash.h revision 69531 
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 * $FreeBSD: head/usr.bin/make/hash.h 69531 2000-12-02 20:24:42Z will $
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
55typedef struct Hash_Entry {
56    struct Hash_Entry *next;		/* Used to link together all the
57    					 * entries associated with the same
58					 * bucket. */
59    void *	      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
65typedef 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
78typedef 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 * void * 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 = (void *) (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
109void Hash_InitTable __P((Hash_Table *, int));
110void Hash_DeleteTable __P((Hash_Table *));
111Hash_Entry *Hash_FindEntry __P((Hash_Table *, char *));
112Hash_Entry *Hash_CreateEntry __P((Hash_Table *, char *, Boolean *));
113void Hash_DeleteEntry __P((Hash_Table *, Hash_Entry *));
114Hash_Entry *Hash_EnumFirst __P((Hash_Table *, Hash_Search *));
115Hash_Entry *Hash_EnumNext __P((Hash_Search *));
116
117#endif /* _HASH */
118