/*	$NetBSD: hash.h,v 1.31 2020/10/25 19:19:07 rillig Exp $	*/

/*
 * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
 *
 * This code is derived from software contributed to Berkeley by
 * Adam de Boor.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	from: @(#)hash.h	8.1 (Berkeley) 6/6/93
 */

/*
 * Copyright (c) 1988, 1989 by Adam de Boor
 * Copyright (c) 1989 by Berkeley Softworks
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Adam de Boor.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	from: @(#)hash.h	8.1 (Berkeley) 6/6/93
 */

/* Hash tables with strings as keys and arbitrary pointers as values. */

#ifndef	MAKE_HASH_H
#define	MAKE_HASH_H

/* A single key-value entry in the hash table. */
typedef struct HashEntry {
    struct HashEntry *next;	/* Used to link together all the entries
				 * associated with the same bucket. */
    void *value;
    unsigned int key_hash;	/* hash value of the key */
    char key[1];		/* key string, variable length */
} HashEntry;

/* The hash table containing the entries. */
typedef struct HashTable {
    HashEntry **buckets;	/* Pointers to HashEntry, one
				 * for each bucket in the table. */
    unsigned int bucketsSize;
    unsigned int numEntries;	/* Number of entries in the table. */
    unsigned int bucketsMask;	/* Used to select the bucket for a hash. */
    unsigned int maxchain;	/* max length of chain detected */
} HashTable;

/* State of an iteration over all entries in a table. */
typedef struct HashIter {
    HashTable *table;		/* Table being searched. */
    unsigned int nextBucket;	/* Next bucket to check (after current). */
    HashEntry *entry;		/* Next entry to check in current bucket. */
} HashIter;

static inline MAKE_ATTR_UNUSED void *
HashEntry_Get(HashEntry *h)
{
    return h->value;
}

static inline MAKE_ATTR_UNUSED void
HashEntry_Set(HashEntry *h, void *datum)
{
    h->value = datum;
}

void HashTable_Init(HashTable *);
void HashTable_Done(HashTable *);
HashEntry *HashTable_FindEntry(HashTable *, const char *);
void *HashTable_FindValue(HashTable *, const char *);
unsigned int Hash_Hash(const char *);
void *HashTable_FindValueHash(HashTable *, const char *, unsigned int);
HashEntry *HashTable_CreateEntry(HashTable *, const char *, Boolean *);
void HashTable_DeleteEntry(HashTable *, HashEntry *);
void HashTable_DebugStats(HashTable *, const char *);

void HashIter_Init(HashIter *, HashTable *);
HashEntry *HashIter_Next(HashIter *);

#endif /* MAKE_HASH_H */