hash.h revision 94589 
1/*
2 * Copyright (c) 1988, 1989, 1990, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 * Copyright (c) 1988, 1989 by Adam de Boor
5 * Copyright (c) 1989 by Berkeley Softworks
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Adam de Boor.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 *    must display the following acknowledgement:
21 *	This product includes software developed by the University of
22 *	California, Berkeley and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 *    may be used to endorse or promote products derived from this software
25 *    without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
39 *	@(#)hash.h	8.1 (Berkeley) 6/6/93
40 * $FreeBSD: head/usr.bin/make/hash.h 94589 2002-04-13 10:57:56Z obrien $
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    void *	      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;/* Pointers to Hash_Entry, one
68    				 * for each bucket in the table. */
69    int 	size;		/* Actual size of array. */
70    int 	numEntries;	/* Number of entries in the table. */
71    int 	mask;		/* Used to select bits for hashing. */
72} Hash_Table;
73
74/*
75 * The following structure is used by the searching routines
76 * to record where we are in the search.
77 */
78
79typedef struct Hash_Search {
80    Hash_Table  *tablePtr;	/* Table being searched. */
81    int 	nextIndex;	/* Next bucket to check (after current). */
82    Hash_Entry 	*hashEntryPtr;	/* Next entry to check in current bucket. */
83} Hash_Search;
84
85/*
86 * Macros.
87 */
88
89/*
90 * void * Hash_GetValue(h)
91 *     Hash_Entry *h;
92 */
93
94#define Hash_GetValue(h) ((h)->clientData)
95
96/*
97 * Hash_SetValue(h, val);
98 *     Hash_Entry *h;
99 *     char *val;
100 */
101
102#define Hash_SetValue(h, val) ((h)->clientData = (void *) (val))
103
104/*
105 * Hash_Size(n) returns the number of words in an object of n bytes
106 */
107
108#define	Hash_Size(n)	(((n) + sizeof (int) - 1) / sizeof (int))
109
110void Hash_InitTable(Hash_Table *, int);
111void Hash_DeleteTable(Hash_Table *);
112Hash_Entry *Hash_FindEntry(Hash_Table *, char *);
113Hash_Entry *Hash_CreateEntry(Hash_Table *, char *, Boolean *);
114void Hash_DeleteEntry(Hash_Table *, Hash_Entry *);
115Hash_Entry *Hash_EnumFirst(Hash_Table *, Hash_Search *);
116Hash_Entry *Hash_EnumNext(Hash_Search *);
117
118#endif /* _HASH */
119