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/*
* This file is part of the sn package.
* Distribution of sn is covered by the GNU GPL. See file COPYING.
* Copyright 1998-2000 Harold Tay.
* Copyright 2000- Patrik Rdman.
*/
/*
* Generic hash table lookup. Store only keys, not data. All keys
* must be unique. Cannot delete. This is used in 2 places: to
* store a list of subscribed newsgroups in snntpd; and to remember
* seen message IDs in snfetch.
*/
#include <stdlib.h>
#include "key.h"
static const char rcsid[] = "$Id$";
struct buf {
struct buf *next;
char buf[1000];
};
static struct buf *head;
static int avail = 0;
static char *keybuf = 0;
struct key *key_table[KEY_TABLE_SIZE] = { 0, };
int nr_keys = 0;
static unsigned hv;
static void hash (char *key, int len)
{
hv = 5381;
while (len)
{
--len;
hv += (hv << 5);
hv ^= (unsigned int) *key++;
}
hv %= 128;
}
char *key_exists (char *key, int len)
{
struct key *kp;
hash(key, len);
for (kp = key_table[hv]; kp; kp = kp->next)
if (kp->len == len)
if (0 == memcmp(KEY(kp), key, len))
return (KEY(kp));
return (0);
}
int key_add (char **keyp, int len)
{
struct key *kp;
char *key;
int size;
key = *keyp;
if (key_exists(key, len))
return (1);
size = len + sizeof (*kp);
size += 4 - (size % 4);
if (avail < size)
{
struct buf *x;
if (!(x = malloc(sizeof (struct buf))))
return (-1);
x->next = head;
head = x;
avail = 1000;
keybuf = head->buf;
}
kp = (struct key *) keybuf;
kp->len = len;
memcpy(*keyp = KEY(kp), key, len + 1); /* Bugfix: +1 so that it copies the '\0' also. */
kp->next = key_table[hv];
key_table[hv] = kp;
keybuf += size;
avail -= size;
nr_keys++;
return (0);
}
void key_free (void)
{
int i;
for (i = 0; i < sizeof (key_table) / sizeof (*key_table); i++)
key_table[i] = 0;
while (head)
{
struct buf *tmp;
tmp = head->next;
free(head);
head = tmp;
}
nr_keys = avail = 0;
}
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