openldap/servers/slapd/back-bdb/dbcache.c
2003-06-05 11:55:27 +00:00

159 lines
3.4 KiB
C

/* dbcache.c - manage cache of open databases */
/* $OpenLDAP$ */
/*
* Copyright 1998-2003 The OpenLDAP Foundation, All Rights Reserved.
* COPYING RESTRICTIONS APPLY, see COPYRIGHT file
*/
#include "portable.h"
#include <stdio.h>
#include <ac/errno.h>
#include <ac/socket.h>
#include <ac/string.h>
#include <ac/time.h>
#include <sys/stat.h>
#include "slap.h"
#include "back-bdb.h"
#include "lutil_hash.h"
/* Pass-thru hash function. Since the indexer is already giving us hash
* values as keys, we don't need BDB to re-hash them.
*/
static u_int32_t
bdb_db_hash(
DB *db,
const void *bytes,
u_int32_t length
)
{
u_int32_t i, ret = 0;
if ( length > sizeof(u_int32_t) )
length = sizeof(u_int32_t);
for( i = 0; i < length; i++ )
ret = (ret << 8) + ((const unsigned char *)bytes)[i];
return ret;
}
int
bdb_db_cache(
Backend *be,
DB_TXN *tid,
const char *name,
DB **dbout )
{
int i;
int rc;
int flags;
struct bdb_info *bdb = (struct bdb_info *) be->be_private;
struct bdb_db_info *db;
char *file;
DBT lockobj;
DB_LOCK lock;
u_int32_t locker = 0;
*dbout = NULL;
for( i=BDB_NDB; i < bdb->bi_ndatabases; i++ ) {
if( !strcmp( bdb->bi_databases[i]->bdi_name, name) ) {
*dbout = bdb->bi_databases[i]->bdi_db;
return 0;
}
}
lockobj.data = "bdb_db_cache";
lockobj.size = sizeof("bdb_db_cache");
if (tid) {
locker = TXN_ID( tid );
} else {
#ifdef BDB_REUSE_LOCKERS
#define op NULL /* implicit arg in LOCK_ID */
#endif
rc = LOCK_ID( bdb->bi_dbenv, &locker );
if (rc) return rc;
}
rc = LOCK_GET( bdb->bi_dbenv, locker, 0, &lockobj,
DB_LOCK_WRITE, &lock );
if (rc) return rc;
/* check again! may have been added by another thread */
for( i=BDB_NDB; i < bdb->bi_ndatabases; i++ ) {
if( !strcmp( bdb->bi_databases[i]->bdi_name, name) ) {
*dbout = bdb->bi_databases[i]->bdi_db;
LOCK_PUT( bdb->bi_dbenv, &lock);
return 0;
}
}
if( i >= BDB_INDICES ) {
LOCK_PUT( bdb->bi_dbenv, &lock);
return -1;
}
db = (struct bdb_db_info *) ch_calloc(1, sizeof(struct bdb_db_info));
db->bdi_name = ch_strdup( name );
rc = db_create( &db->bdi_db, bdb->bi_dbenv, 0 );
if( rc != 0 ) {
#ifdef NEW_LOGGING
LDAP_LOG ( CACHE, ERR,
"bdb_db_cache: db_create(%s) failed: %s (%d)\n",
bdb->bi_dbenv_home, db_strerror(rc), rc );
#else
Debug( LDAP_DEBUG_ANY,
"bdb_db_cache: db_create(%s) failed: %s (%d)\n",
bdb->bi_dbenv_home, db_strerror(rc), rc );
#endif
LOCK_PUT( bdb->bi_dbenv, &lock);
return rc;
}
rc = db->bdi_db->set_pagesize( db->bdi_db, BDB_PAGESIZE );
rc = db->bdi_db->set_h_hash( db->bdi_db, bdb_db_hash );
rc = db->bdi_db->set_flags( db->bdi_db, DB_DUP | DB_DUPSORT );
rc = db->bdi_db->set_dup_compare( db->bdi_db, bdb_bt_compare );
file = ch_malloc( strlen( name ) + sizeof(BDB_SUFFIX) );
sprintf( file, "%s" BDB_SUFFIX, name );
#ifdef HAVE_EBCDIC
__atoe( file );
#endif
flags = bdb->bi_db_opflags | DB_CREATE | DB_THREAD;
if ( !tid ) flags |= DB_AUTO_COMMIT;
rc = DB_OPEN( db->bdi_db, tid,
file, NULL /* name */,
DB_HASH, flags,
bdb->bi_dbenv_mode );
ch_free( file );
if( rc != 0 ) {
#ifdef NEW_LOGGING
LDAP_LOG ( CACHE, ERR,
"bdb_db_cache: db_open(%s) failed: %s (%d)\n",
name, db_strerror(rc), rc );
#else
Debug( LDAP_DEBUG_ANY,
"bdb_db_cache: db_open(%s) failed: %s (%d)\n",
name, db_strerror(rc), rc );
#endif
LOCK_PUT( bdb->bi_dbenv, &lock);
return rc;
}
bdb->bi_databases[i] = db;
bdb->bi_ndatabases = i+1;
*dbout = db->bdi_db;
LOCK_PUT( bdb->bi_dbenv, &lock );
return 0;
}