pjs/dbm/src/db.c

147 строки
4.3 KiB
C

/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)db.c 8.4 (Berkeley) 2/21/94";
#endif /* LIBC_SCCS and not lint */
#include "watcomfx.h"
#ifndef __DBINTERFACE_PRIVATE
#define __DBINTERFACE_PRIVATE
#endif
#ifdef macintosh
#include <unix.h>
#else
#include <sys/types.h>
#endif
#include <errno.h>
#ifndef macintosh
#include <fcntl.h>
#endif
#include <stddef.h>
#include <stdio.h>
#include "mcom_db.h"
/* a global flag that locks closed all databases */
int all_databases_locked_closed = 0;
/* set or unset a global lock flag to disable the
* opening of any DBM file
*/
void
dbSetOrClearDBLock(DBLockFlagEnum type)
{
if(type == LockOutDatabase)
all_databases_locked_closed = 1;
else
all_databases_locked_closed = 0;
}
#if defined(__WATCOMC__) || defined(__WATCOM_CPLUSPLUS__)
DB *
#else
PR_IMPLEMENT(DB *)
#endif
dbopen(const char *fname, int flags,int mode, DBTYPE type, const void *openinfo)
{
/* lock out all file databases. Let in-memory databases through
*/
if(all_databases_locked_closed && fname)
{
errno = EINVAL;
return(NULL);
}
#define DB_FLAGS (DB_LOCK | DB_SHMEM | DB_TXN)
#if 0 /* most systems dont have EXLOCK and SHLOCK */
#define USE_OPEN_FLAGS \
(O_CREAT | O_EXCL | O_EXLOCK | O_NONBLOCK | O_RDONLY | \
O_RDWR | O_SHLOCK | O_TRUNC)
#else
#define USE_OPEN_FLAGS \
(O_CREAT | O_EXCL | O_RDONLY | \
O_RDWR | O_TRUNC)
#endif
if ((flags & ~(USE_OPEN_FLAGS | DB_FLAGS)) == 0)
switch (type) {
/* we don't need btree and recno right now */
#if 0
case DB_BTREE:
return (__bt_open(fname, flags & USE_OPEN_FLAGS,
mode, openinfo, flags & DB_FLAGS));
case DB_RECNO:
return (__rec_open(fname, flags & USE_OPEN_FLAGS,
mode, openinfo, flags & DB_FLAGS));
#endif
case DB_HASH:
return (__hash_open(fname, flags & USE_OPEN_FLAGS,
mode, (const HASHINFO *)openinfo, flags & DB_FLAGS));
default:
break;
}
errno = EINVAL;
return (NULL);
}
static int
__dberr()
{
return (RET_ERROR);
}
/*
* __DBPANIC -- Stop.
*
* Parameters:
* dbp: pointer to the DB structure.
*/
void
__dbpanic(DB *dbp)
{
/* The only thing that can succeed is a close. */
dbp->del = (int (*)(const struct __db *, const DBT *, uint))__dberr;
dbp->fd = (int (*)(const struct __db *))__dberr;
dbp->get = (int (*)(const struct __db *, const DBT *, DBT *, uint))__dberr;
dbp->put = (int (*)(const struct __db *, DBT *, const DBT *, uint))__dberr;
dbp->seq = (int (*)(const struct __db *, DBT *, DBT *, uint))__dberr;
dbp->sync = (int (*)(const struct __db *, uint))__dberr;
}