elemental-ircd/src/scache.c

139 lines
3.4 KiB
C

/*
* ircd-ratbox: A slightly useful ircd.
* scache.c: Server names cache.
*
* Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center
* Copyright (C) 1996-2002 Hybrid Development Team
* Copyright (C) 2002-2005 ircd-ratbox development team
*
* 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 02111-1307
* USA
*
* $Id: scache.c 6 2005-09-10 01:02:21Z nenolod $
*/
#include "stdinc.h"
#include "client.h"
#include "common.h"
#include "irc_string.h"
#include "ircd.h"
#include "numeric.h"
#include "send.h"
#include "scache.h"
#include "memory.h"
/*
* ircd used to store full servernames in anUser as well as in the
* whowas info. there can be some 40k such structures alive at any
* given time, while the number of unique server names a server sees
* in its lifetime is at most a few hundred. by tokenizing server
* names internally, the server can easily save 2 or 3 megs of RAM.
* -orabidoo
*/
#define SCACHE_HASH_SIZE 257
typedef struct scache_entry
{
char name[HOSTLEN + 1];
struct scache_entry *next;
}
SCACHE;
static SCACHE *scache_hash[SCACHE_HASH_SIZE];
void
clear_scache_hash_table(void)
{
memset(scache_hash, 0, sizeof(scache_hash));
}
static int
sc_hash(const char *string)
{
int hash_value;
hash_value = 0;
while (*string)
{
hash_value += ToLower(*string++);
}
return hash_value % SCACHE_HASH_SIZE;
}
/*
* this takes a server name, and returns a pointer to the same string
* (up to case) in the server name token list, adding it to the list if
* it's not there. care must be taken not to call this with
* user-supplied arguments that haven't been verified to be a valid,
* existing, servername. use the hash in list.c for those. -orabidoo
*/
const char *
find_or_add(const char *name)
{
int hash_index;
SCACHE *ptr;
ptr = scache_hash[hash_index = sc_hash(name)];
for (; ptr; ptr = ptr->next)
{
if(!irccmp(ptr->name, name))
return (ptr->name);
}
ptr = (SCACHE *) MyMalloc(sizeof(SCACHE));
s_assert(0 != ptr);
strlcpy(ptr->name, name, sizeof(ptr->name));
ptr->next = scache_hash[hash_index];
scache_hash[hash_index] = ptr;
return ptr->name;
}
/*
* count_scache
* inputs - pointer to where to leave number of servers cached
* - pointer to where to leave total memory usage
* output - NONE
* side effects -
*/
void
count_scache(size_t * number_servers_cached, size_t * mem_servers_cached)
{
SCACHE *scache_ptr;
int i;
*number_servers_cached = 0;
*mem_servers_cached = 0;
for (i = 0; i < SCACHE_HASH_SIZE; i++)
{
scache_ptr = scache_hash[i];
while (scache_ptr)
{
*number_servers_cached = *number_servers_cached + 1;
*mem_servers_cached = *mem_servers_cached +
(strlen(scache_ptr->name) + sizeof(SCACHE *));
scache_ptr = scache_ptr->next;
}
}
}