quakeforge/libs/util/hash.c
Bill Currie 4489319298 first step towards garbage collected dynamic strings in qc. All strings
external to the progs file are now malloced and then freed at progs reload.
All that needs to be implementd for gc to work is the scanner and deallocator.
2001-03-06 04:22:33 +00:00

159 lines
3.2 KiB
C

/*
hash.h
hash tables
Copyright (C) 1996-1997 Id Software, Inc.
Copyright (C) 2000 Marcus Sundberg <mackan@stacken.kth.se>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to:
Free Software Foundation, Inc.
59 Temple Place - Suite 330
Boston, MA 02111-1307, USA
$Id$
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#ifdef HAVE_STRING_H
# include <string.h>
#endif
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif
#include "compat.h"
#include "hash.h"
static unsigned long
hash (const char *str)
{
//FIXME not 64 bit clean
#if 0
unsigned long h = 0;
while (*str) {
h = (h << 4) + (unsigned char)*str++;
if (h&0xf0000000)
h = (h ^ (h >> 24)) & 0xfffffff;
}
return h;
#else
// dx_hack_hash
// shamelessly stolen from Daniel Phillips <phillips@innominate.de>
// from his post to lkml
unsigned long hash0 = 0x12a3fe2d, hash1 = 0x37abe8f9;
while (*str)
{
unsigned long hash = hash1 + (hash0 ^ (*str++ * 71523));
if (hash < 0) hash -= 0x7fffffff;
hash1 = hash0;
hash0 = hash;
}
return hash0;
#endif
}
hashtab_t *
Hash_NewTable (int tsize, char *(*gk)(void*,void*), void (*f)(void*,void*),
void *ud)
{
hashtab_t *tab = calloc (1, (size_t)&((hashtab_t*)0)->tab[tsize]);
if (!tab)
return 0;
tab->tab_size = tsize;
tab->user_data = ud;
tab->get_key = gk;
tab->free_ele = f;
return tab;
}
void
Hash_DelTable (hashtab_t *tab)
{
Hash_FlushTable (tab);
free (tab);
}
void
Hash_FlushTable (hashtab_t *tab)
{
int i;
for (i = 0; i < tab->tab_size; i++) {
while (tab->tab[i]) {
hashlink_t *t = tab->tab[i]->next;
if (tab->free_ele)
tab->free_ele (tab->tab[i]->data, tab->user_data);
free (tab->tab[i]);
tab->tab[i] = t;
}
}
}
int
Hash_Add (hashtab_t *tab, void *ele)
{
unsigned long h = hash (tab->get_key(ele, tab->user_data));
size_t ind = h % tab->tab_size;
hashlink_t *lnk = malloc (sizeof (hashlink_t));
if (!lnk)
return -1;
if (tab->tab[ind])
tab->tab[ind]->prev = &lnk->next;
lnk->next = tab->tab[ind];
lnk->prev = &tab->tab[ind];
lnk->data = ele;
tab->tab[ind] = lnk;
return 0;
}
void *
Hash_Find (hashtab_t *tab, const char *key)
{
unsigned long h = hash (key);
size_t ind = h % tab->tab_size;
hashlink_t *lnk = tab->tab[ind];
while (lnk) {
if (strequal (key, tab->get_key (lnk->data, tab->user_data)))
return lnk->data;
lnk = lnk->next;
}
return 0;
}
int
Hash_Del (hashtab_t *tab, const char *key)
{
unsigned long h = hash (key);
size_t ind = h % tab->tab_size;
hashlink_t *lnk = tab->tab[ind];
while (lnk) {
if (strequal (key, tab->get_key (lnk->data, tab->user_data))) {
if (lnk->next)
lnk->next->prev = lnk->prev;
*lnk->prev = lnk->next;
free (lnk);
return 0;
}
lnk = lnk->next;
}
return -1;
}