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hash.h revision 1.43 
      1 /*	$NetBSD: hash.h,v 1.43 2021/12/15 10:07:53 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 * MAKE_ATTR_USE
    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 /* Set things up for iterating over all entries in the hash table. */
    124 MAKE_INLINE void
    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 void HashIter_Init(HashIter *, HashTable *);
    145 HashEntry *HashIter_Next(HashIter *);
    146 
    147 MAKE_INLINE void
    148 HashSet_Init(HashSet *set)
    149 {
    150 	HashTable_Init(&set->tbl);
    151 }
    152 
    153 MAKE_INLINE void
    154 HashSet_Done(HashSet *set)
    155 {
    156 	HashTable_Done(&set->tbl);
    157 }
    158 
    159 MAKE_INLINE bool
    160 HashSet_Add(HashSet *set, const char *key)
    161 {
    162 	bool isNew;
    163 
    164 	(void)HashTable_CreateEntry(&set->tbl, key, &isNew);
    165 	return isNew;
    166 }
    167 
    168 MAKE_INLINE bool MAKE_ATTR_USE
    169 HashSet_Contains(HashSet *set, const char *key)
    170 {
    171 	return HashTable_FindEntry(&set->tbl, key) != NULL;
    172 }
    173 
    174 MAKE_INLINE void
    175 HashIter_InitSet(HashIter *hi, HashSet *set)
    176 {
    177 	HashIter_Init(hi, &set->tbl);
    178 }
    179 
    180 #endif /* MAKE_HASH_H */
    181