1/*	$NetBSD: hash.h,v 1.48 2023/12/19 19:33:39 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. */
81typedef 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. */
90typedef 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	unsigned int maxchain;	/* Maximum length of chain seen. */
96} HashTable;
97
98/* State of an iteration over all entries in a table. */
99typedef struct HashIter {
100	HashTable *table;	/* Table being searched. */
101	unsigned int nextBucket; /* Next bucket to check (after current). */
102	HashEntry *entry;	/* Next entry to check in current bucket. */
103} HashIter;
104
105/* A set of strings. */
106typedef struct HashSet {
107	HashTable tbl;
108} HashSet;
109
110MAKE_INLINE void * MAKE_ATTR_USE
111HashEntry_Get(HashEntry *he)
112{
113	return he->value;
114}
115
116MAKE_INLINE void
117HashEntry_Set(HashEntry *he, void *datum)
118{
119	he->value = datum;
120}
121
122/* Set things up for iterating over all entries in the hash table. */
123MAKE_INLINE void
124HashIter_Init(HashIter *hi, HashTable *t)
125{
126	hi->table = t;
127	hi->nextBucket = 0;
128	hi->entry = NULL;
129}
130
131void HashTable_Init(HashTable *);
132void HashTable_Done(HashTable *);
133HashEntry *HashTable_FindEntry(HashTable *, const char *) MAKE_ATTR_USE;
134void *HashTable_FindValue(HashTable *, const char *) MAKE_ATTR_USE;
135unsigned int Hash_Substring(Substring) MAKE_ATTR_USE;
136void *HashTable_FindValueBySubstringHash(HashTable *, Substring, unsigned int)
137    MAKE_ATTR_USE;
138HashEntry *HashTable_CreateEntry(HashTable *, const char *, bool *);
139void HashTable_Set(HashTable *, const char *, void *);
140void HashTable_DeleteEntry(HashTable *, HashEntry *);
141void HashTable_DebugStats(HashTable *, const char *);
142
143HashEntry *HashIter_Next(HashIter *);
144
145MAKE_INLINE void
146HashSet_Init(HashSet *set)
147{
148	HashTable_Init(&set->tbl);
149}
150
151MAKE_INLINE void
152HashSet_Done(HashSet *set)
153{
154	HashTable_Done(&set->tbl);
155}
156
157MAKE_INLINE bool
158HashSet_Add(HashSet *set, const char *key)
159{
160	bool isNew;
161
162	(void)HashTable_CreateEntry(&set->tbl, key, &isNew);
163	return isNew;
164}
165
166MAKE_INLINE bool MAKE_ATTR_USE
167HashSet_Contains(HashSet *set, const char *key)
168{
169	return HashTable_FindEntry(&set->tbl, key) != NULL;
170}
171
172MAKE_INLINE void
173HashIter_InitSet(HashIter *hi, HashSet *set)
174{
175	HashIter_Init(hi, &set->tbl);
176}
177
178#endif
179