xref: /freebsd/contrib/bmake/hash.h (revision a64729f5077d77e13b9497cb33ecb3c82e606ee8)
1 /*	$NetBSD: hash.h,v 1.51 2024/07/07 09:37:00 rillig Exp $	*/
2 
3 /*
4  * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
5  *
6  * This code is derived from software contributed to Berkeley by
7  * Adam de Boor.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	from: @(#)hash.h	8.1 (Berkeley) 6/6/93
34  */
35 
36 /*
37  * Copyright (c) 1988, 1989 by Adam de Boor
38  * Copyright (c) 1989 by Berkeley Softworks
39  * All rights reserved.
40  *
41  * This code is derived from software contributed to Berkeley by
42  * Adam de Boor.
43  *
44  * Redistribution and use in source and binary forms, with or without
45  * modification, are permitted provided that the following conditions
46  * are met:
47  * 1. Redistributions of source code must retain the above copyright
48  *    notice, this list of conditions and the following disclaimer.
49  * 2. Redistributions in binary form must reproduce the above copyright
50  *    notice, this list of conditions and the following disclaimer in the
51  *    documentation and/or other materials provided with the distribution.
52  * 3. All advertising materials mentioning features or use of this software
53  *    must display the following acknowledgement:
54  *	This product includes software developed by the University of
55  *	California, Berkeley and its contributors.
56  * 4. Neither the name of the University nor the names of its contributors
57  *    may be used to endorse or promote products derived from this software
58  *    without specific prior written permission.
59  *
60  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
61  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
62  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
63  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
64  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
65  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
66  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
67  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
68  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
69  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
70  * SUCH DAMAGE.
71  *
72  *	from: @(#)hash.h	8.1 (Berkeley) 6/6/93
73  */
74 
75 /* Hash tables with string keys and pointer values. */
76 
77 #ifndef MAKE_HASH_H
78 #define MAKE_HASH_H
79 
80 /* A single key-value entry in the hash table. */
81 typedef struct HashEntry {
82 	struct HashEntry *next;	/* Used to link together all the entries
83 				 * associated with the same bucket. */
84 	void *value;
85 	unsigned int hash;	/* hash value of the key */
86 	char key[1];		/* key string, variable length */
87 } HashEntry;
88 
89 /* The hash table containing the entries. */
90 typedef struct HashTable {
91 	HashEntry **buckets;
92 	unsigned int bucketsSize;
93 	unsigned int numEntries;
94 	unsigned int bucketsMask; /* Used to select the bucket for a hash. */
95 } HashTable;
96 
97 /* State of an iteration over all entries in a table. */
98 typedef struct HashIter {
99 	HashTable *table;	/* Table being searched. */
100 	unsigned int nextBucket; /* Next bucket to check (after current). */
101 	HashEntry *entry;	/* Next entry to check in current bucket. */
102 } HashIter;
103 
104 /* A set of strings. */
105 typedef struct HashSet {
106 	HashTable tbl;
107 } HashSet;
108 
109 MAKE_INLINE void * MAKE_ATTR_USE
110 HashEntry_Get(HashEntry *he)
111 {
112 	return he->value;
113 }
114 
115 MAKE_INLINE void
116 HashEntry_Set(HashEntry *he, void *datum)
117 {
118 	he->value = datum;
119 }
120 
121 /* Set things up for iterating over all entries in the hash table. */
122 MAKE_INLINE void
123 HashIter_Init(HashIter *hi, HashTable *t)
124 {
125 	hi->table = t;
126 	hi->nextBucket = 0;
127 	hi->entry = NULL;
128 }
129 
130 void HashTable_Init(HashTable *);
131 void HashTable_Done(HashTable *);
132 HashEntry *HashTable_FindEntry(HashTable *, const char *) MAKE_ATTR_USE;
133 void *HashTable_FindValue(HashTable *, const char *) MAKE_ATTR_USE;
134 unsigned int Hash_Substring(Substring) MAKE_ATTR_USE;
135 void *HashTable_FindValueBySubstringHash(HashTable *, Substring, unsigned int)
136     MAKE_ATTR_USE;
137 HashEntry *HashTable_CreateEntry(HashTable *, const char *, bool *);
138 void HashTable_Set(HashTable *, const char *, void *);
139 void HashTable_DeleteEntry(HashTable *, HashEntry *);
140 void HashTable_DebugStats(const HashTable *, const char *);
141 
142 bool HashIter_Next(HashIter *) MAKE_ATTR_USE;
143 
144 MAKE_INLINE void
145 HashSet_Init(HashSet *set)
146 {
147 	HashTable_Init(&set->tbl);
148 }
149 
150 MAKE_INLINE void
151 HashSet_Done(HashSet *set)
152 {
153 	HashTable_Done(&set->tbl);
154 }
155 
156 MAKE_INLINE bool
157 HashSet_Add(HashSet *set, const char *key)
158 {
159 	bool isNew;
160 
161 	(void)HashTable_CreateEntry(&set->tbl, key, &isNew);
162 	return isNew;
163 }
164 
165 MAKE_INLINE bool MAKE_ATTR_USE
166 HashSet_Contains(HashSet *set, const char *key)
167 {
168 	return HashTable_FindEntry(&set->tbl, key) != NULL;
169 }
170 
171 MAKE_INLINE void
172 HashIter_InitSet(HashIter *hi, HashSet *set)
173 {
174 	HashIter_Init(hi, &set->tbl);
175 }
176 
177 #endif
178