1 /* $NetBSD: hash.h,v 1.46 2022/01/31 22:58:26 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 for each bucket
92 * 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 * MAKE_ATTR_USE
HashEntry_Get(HashEntry * h)112 HashEntry_Get(HashEntry *h)
113 {
114 return h->value;
115 }
116
117 MAKE_INLINE void
HashEntry_Set(HashEntry * h,void * datum)118 HashEntry_Set(HashEntry *h, void *datum)
119 {
120 h->value = datum;
121 }
122
123 /* Set things up for iterating over all entries in the hash table. */
124 MAKE_INLINE void
HashIter_Init(HashIter * hi,HashTable * t)125 HashIter_Init(HashIter *hi, HashTable *t)
126 {
127 hi->table = t;
128 hi->nextBucket = 0;
129 hi->entry = NULL;
130 }
131
132 void HashTable_Init(HashTable *);
133 void HashTable_Done(HashTable *);
134 HashEntry *HashTable_FindEntry(HashTable *, const char *) MAKE_ATTR_USE;
135 void *HashTable_FindValue(HashTable *, const char *) MAKE_ATTR_USE;
136 unsigned int Hash_Substring(Substring) MAKE_ATTR_USE;
137 void *HashTable_FindValueBySubstringHash(HashTable *, Substring, unsigned int)
138 MAKE_ATTR_USE;
139 HashEntry *HashTable_CreateEntry(HashTable *, const char *, bool *);
140 void HashTable_Set(HashTable *, const char *, void *);
141 void HashTable_DeleteEntry(HashTable *, HashEntry *);
142 void HashTable_DebugStats(HashTable *, const char *);
143
144 HashEntry *HashIter_Next(HashIter *);
145
146 MAKE_INLINE void
HashSet_Init(HashSet * set)147 HashSet_Init(HashSet *set)
148 {
149 HashTable_Init(&set->tbl);
150 }
151
152 MAKE_INLINE void
HashSet_Done(HashSet * set)153 HashSet_Done(HashSet *set)
154 {
155 HashTable_Done(&set->tbl);
156 }
157
158 MAKE_INLINE bool
HashSet_Add(HashSet * set,const char * key)159 HashSet_Add(HashSet *set, const char *key)
160 {
161 bool isNew;
162
163 (void)HashTable_CreateEntry(&set->tbl, key, &isNew);
164 return isNew;
165 }
166
167 MAKE_INLINE bool MAKE_ATTR_USE
HashSet_Contains(HashSet * set,const char * key)168 HashSet_Contains(HashSet *set, const char *key)
169 {
170 return HashTable_FindEntry(&set->tbl, key) != NULL;
171 }
172
173 MAKE_INLINE void
HashIter_InitSet(HashIter * hi,HashSet * set)174 HashIter_InitSet(HashIter *hi, HashSet *set)
175 {
176 HashIter_Init(hi, &set->tbl);
177 }
178
179 #endif
180