xref: /freebsd/contrib/bmake/hash.h (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*	$NetBSD: hash.h,v 1.38 2020/12/15 01:23:55 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 strings as keys and arbitrary pointers as 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 key_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;	/* Pointers to HashEntry, one
92 				 * for each bucket in the table. */
93 	unsigned int bucketsSize;
94 	unsigned int numEntries; /* Number of entries in the table. */
95 	unsigned int bucketsMask; /* Used to select the bucket for a hash. */
96 	unsigned int maxchain;	/* max length of chain detected */
97 } HashTable;
98 
99 /* State of an iteration over all entries in a table. */
100 typedef struct HashIter {
101 	HashTable *table;	/* Table being searched. */
102 	unsigned int nextBucket; /* Next bucket to check (after current). */
103 	HashEntry *entry;	/* Next entry to check in current bucket. */
104 } HashIter;
105 
106 /* A set of strings. */
107 typedef struct HashSet {
108 	HashTable tbl;
109 } HashSet;
110 
111 MAKE_INLINE void *
112 HashEntry_Get(HashEntry *h)
113 {
114 	return h->value;
115 }
116 
117 MAKE_INLINE void
118 HashEntry_Set(HashEntry *h, void *datum)
119 {
120 	h->value = datum;
121 }
122 
123 void HashTable_Init(HashTable *);
124 void HashTable_Done(HashTable *);
125 HashEntry *HashTable_FindEntry(HashTable *, const char *);
126 void *HashTable_FindValue(HashTable *, const char *);
127 unsigned int Hash_Hash(const char *);
128 void *HashTable_FindValueHash(HashTable *, const char *, unsigned int);
129 HashEntry *HashTable_CreateEntry(HashTable *, const char *, Boolean *);
130 HashEntry *HashTable_Set(HashTable *, const char *, void *);
131 void HashTable_DeleteEntry(HashTable *, HashEntry *);
132 void HashTable_DebugStats(HashTable *, const char *);
133 
134 void HashIter_Init(HashIter *, HashTable *);
135 HashEntry *HashIter_Next(HashIter *);
136 
137 MAKE_INLINE void
138 HashSet_Init(HashSet *set)
139 {
140 	HashTable_Init(&set->tbl);
141 }
142 
143 MAKE_INLINE void
144 HashSet_Done(HashSet *set)
145 {
146 	HashTable_Done(&set->tbl);
147 }
148 
149 MAKE_INLINE Boolean
150 HashSet_Add(HashSet *set, const char *key)
151 {
152 	Boolean isNew;
153 
154 	(void)HashTable_CreateEntry(&set->tbl, key, &isNew);
155 	return isNew;
156 }
157 
158 MAKE_INLINE Boolean
159 HashSet_Contains(HashSet *set, const char *key)
160 {
161 	return HashTable_FindEntry(&set->tbl, key) != NULL;
162 }
163 
164 MAKE_INLINE void
165 HashIter_InitSet(HashIter *hi, HashSet *set)
166 {
167 	HashIter_Init(hi, &set->tbl);
168 }
169 
170 #endif /* MAKE_HASH_H */
171