mariadb/bdb/common/util_cache.c
ram@mysql.r18.ru 5e09392faa BDB 4.1.24
2002-10-30 15:57:05 +04:00

92 lines
1.8 KiB
C

/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 2000-2002
* Sleepycat Software. All rights reserved.
*/
#include "db_config.h"
#ifndef lint
static const char revid[] = "$Id: util_cache.c,v 1.3 2002/04/04 18:50:10 bostic Exp $";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#endif
#include "db_int.h"
/*
* __db_util_cache --
* Compute if we have enough cache.
*
* PUBLIC: int __db_util_cache __P((DB_ENV *, DB *, u_int32_t *, int *));
*/
int
__db_util_cache(dbenv, dbp, cachep, resizep)
DB_ENV *dbenv;
DB *dbp;
u_int32_t *cachep;
int *resizep;
{
DBTYPE type;
DB_BTREE_STAT *bsp;
DB_HASH_STAT *hsp;
DB_QUEUE_STAT *qsp;
u_int32_t pgsize;
int ret;
void *sp;
/*
* The current cache size is in cachep. If it's insufficient, set the
* the memory referenced by resizep to 1 and set cachep to the minimum
* size needed.
*/
if ((ret = dbp->get_type(dbp, &type)) != 0) {
dbenv->err(dbenv, ret, "DB->get_type");
return (ret);
}
if ((ret = dbp->stat(dbp, &sp, DB_FAST_STAT)) != 0) {
dbenv->err(dbenv, ret, "DB->stat");
return (ret);
}
switch (type) {
case DB_QUEUE:
qsp = (DB_QUEUE_STAT *)sp;
pgsize = qsp->qs_pagesize;
break;
case DB_HASH:
hsp = (DB_HASH_STAT *)sp;
pgsize = hsp->hash_pagesize;
break;
case DB_BTREE:
case DB_RECNO:
bsp = (DB_BTREE_STAT *)sp;
pgsize = bsp->bt_pagesize;
break;
default:
dbenv->err(dbenv, ret, "unknown database type: %d", type);
return (EINVAL);
}
free(sp);
/*
* Make sure our current cache is big enough. We want at least
* DB_MINPAGECACHE pages in the cache.
*/
if ((*cachep / pgsize) < DB_MINPAGECACHE) {
*resizep = 1;
*cachep = pgsize * DB_MINPAGECACHE;
} else
*resizep = 0;
return (0);
}