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/*
* Copyright (C) 1996-2000 Michael R. Elkins <me@cs.hmc.edu>
*
* 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 the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "mutt.h"
#define SOMEPRIME 149711
int hash_string (const unsigned char *s, int n)
{
int h = 0;
#if 0
while (*s)
h += *s++;
#else
while (*s)
h += (h << 7) + *s++;
h = (h * SOMEPRIME) % n;
h = (h >= 0) ? h : h + n;
#endif
return (h % n);
}
HASH *hash_create (int nelem)
{
HASH *table = safe_malloc (sizeof (HASH));
table->nelem = nelem;
table->table = safe_calloc (nelem, sizeof (struct hash_elem *));
return table;
}
/* table hash table to update
* key key to hash on
* data data to associate with `key'
* allow_dup if nonzero, duplicate keys are allowed in the table
*/
int hash_insert (HASH * table, const char *key, void *data, int allow_dup)
{
struct hash_elem *ptr;
int h;
ptr = (struct hash_elem *) safe_malloc (sizeof (struct hash_elem));
h = hash_string ((unsigned char *) key, table->nelem);
ptr->key = key;
ptr->data = data;
if (allow_dup)
{
ptr->next = table->table[h];
table->table[h] = ptr;
}
else
{
struct hash_elem *tmp, *last;
int r;
for (tmp = table->table[h], last = NULL; tmp; last = tmp, tmp = tmp->next)
{
r = mutt_strcmp (tmp->key, key);
if (r == 0)
{
FREE (&ptr);
return (-1);
}
if (r > 0)
break;
}
if (last)
last->next = ptr;
else
table->table[h] = ptr;
ptr->next = tmp;
}
return h;
}
void *hash_find_hash (const HASH * table, int hash, const char *key)
{
struct hash_elem *ptr = table->table[hash];
for (; ptr; ptr = ptr->next)
{
if (mutt_strcmp (key, ptr->key) == 0)
return (ptr->data);
}
return NULL;
}
void hash_delete_hash (HASH * table, int hash, const char *key, const void *data,
void (*destroy) (void *))
{
struct hash_elem *ptr = table->table[hash];
struct hash_elem **last = &table->table[hash];
for (; ptr; last = &ptr->next, ptr = ptr->next)
{
/* if `data' is given, look for a matching ->data member. this is
* required for the case where we have multiple entries with the same
* key
*/
if ((data == ptr->data) || (!data && mutt_strcmp (ptr->key, key) == 0))
{
*last = ptr->next;
if (destroy) destroy (ptr->data);
FREE (&ptr);
return;
}
}
}
/* ptr pointer to the hash table to be freed
* destroy() function to call to free the ->data member (optional)
*/
void hash_destroy (HASH **ptr, void (*destroy) (void *))
{
int i;
HASH *pptr = *ptr;
struct hash_elem *elem, *tmp;
for (i = 0 ; i < pptr->nelem; i++)
{
for (elem = pptr->table[i]; elem; )
{
tmp = elem;
elem = elem->next;
if (destroy)
destroy (tmp->data);
safe_free ((void **) &tmp);
}
}
safe_free ((void **) &pptr->table);
safe_free ((void **) ptr);
}
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