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/*
* Copyright (c) 1997 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* 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 Institute 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 INSTITUTE 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 INSTITUTE 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.
*/
/*
* Hash table functions
*/
#include "gen_locl.h"
RCSID("$Id: hash.c 17016 2006-04-07 22:16:00Z lha $");
static Hashentry *_search(Hashtab * htab, /* The hash table */
void *ptr); /* And key */
Hashtab *
hashtabnew(int sz,
int (*cmp) (void *, void *),
unsigned (*hash) (void *))
{
Hashtab *htab;
int i;
assert(sz > 0);
htab = (Hashtab *) malloc(sizeof(Hashtab) + (sz - 1) * sizeof(Hashentry *));
if (htab == NULL)
return NULL;
for (i = 0; i < sz; ++i)
htab->tab[i] = NULL;
htab->cmp = cmp;
htab->hash = hash;
htab->sz = sz;
return htab;
}
/* Intern search function */
static Hashentry *
_search(Hashtab * htab, void *ptr)
{
Hashentry *hptr;
assert(htab && ptr);
for (hptr = htab->tab[(*htab->hash) (ptr) % htab->sz];
hptr;
hptr = hptr->next)
if ((*htab->cmp) (ptr, hptr->ptr) == 0)
break;
return hptr;
}
/* Search for element in hash table */
void *
hashtabsearch(Hashtab * htab, void *ptr)
{
Hashentry *tmp;
tmp = _search(htab, ptr);
return tmp ? tmp->ptr : tmp;
}
/* add element to hash table */
/* if already there, set new value */
/* !NULL if succesful */
void *
hashtabadd(Hashtab * htab, void *ptr)
{
Hashentry *h = _search(htab, ptr);
Hashentry **tabptr;
assert(htab && ptr);
if (h)
free((void *) h->ptr);
else {
h = (Hashentry *) malloc(sizeof(Hashentry));
if (h == NULL) {
return NULL;
}
tabptr = &htab->tab[(*htab->hash) (ptr) % htab->sz];
h->next = *tabptr;
*tabptr = h;
h->prev = tabptr;
if (h->next)
h->next->prev = &h->next;
}
h->ptr = ptr;
return h;
}
/* delete element with key key. Iff freep, free Hashentry->ptr */
int
_hashtabdel(Hashtab * htab, void *ptr, int freep)
{
Hashentry *h;
assert(htab && ptr);
h = _search(htab, ptr);
if (h) {
if (freep)
free(h->ptr);
if ((*(h->prev) = h->next))
h->next->prev = h->prev;
free(h);
return 0;
} else
return -1;
}
/* Do something for each element */
void
hashtabforeach(Hashtab * htab, int (*func) (void *ptr, void *arg),
void *arg)
{
Hashentry **h, *g;
assert(htab);
for (h = htab->tab; h < &htab->tab[htab->sz]; ++h)
for (g = *h; g; g = g->next)
if ((*func) (g->ptr, arg))
return;
}
/* standard hash-functions for strings */
unsigned
hashadd(const char *s)
{ /* Standard hash function */
unsigned i;
assert(s);
for (i = 0; *s; ++s)
i += *s;
return i;
}
unsigned
hashcaseadd(const char *s)
{ /* Standard hash function */
unsigned i;
assert(s);
for (i = 0; *s; ++s)
i += toupper((unsigned char)*s);
return i;
}
#define TWELVE (sizeof(unsigned))
#define SEVENTYFIVE (6*sizeof(unsigned))
#define HIGH_BITS (~((unsigned)(~0) >> TWELVE))
unsigned
hashjpw(const char *ss)
{ /* another hash function */
unsigned h = 0;
unsigned g;
const unsigned char *s = (const unsigned char *)ss;
for (; *s; ++s) {
h = (h << TWELVE) + *s;
if ((g = h & HIGH_BITS))
h = (h ^ (g >> SEVENTYFIVE)) & ~HIGH_BITS;
}
return h;
}
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