cdesktopenv/cde/lib/tt/mini_isam/isfd.c

102 lines
2.5 KiB
C

/*
* CDE - Common Desktop Environment
*
* Copyright (c) 1993-2012, The Open Group. All rights reserved.
*
* These libraries and programs are free software; you can
* redistribute them and/or modify them under the terms of the GNU
* Lesser General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* These libraries and programs are distributed in the hope that
* they will be useful, but WITHOUT ANY WARRANTY; without even the
* implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with these libraries and programs; if not, write
* to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
* Floor, Boston, MA 02110-1301 USA
*/
/*%% (c) Copyright 1993, 1994 Hewlett-Packard Company */
/*%% (c) Copyright 1993, 1994 International Business Machines Corp. */
/*%% (c) Copyright 1993, 1994 Sun Microsystems, Inc. */
/*%% (c) Copyright 1993, 1994 Novell, Inc. */
/*%% $XConsortium: isfd.c /main/3 1995/10/23 11:39:10 rswiston $ */
/*
* Copyright (c) 1988 by Sun Microsystems, Inc.
*/
/*
* isfd.c
*
* Description:
* The ISAM file descriptors (isfd) are used as index to a table of
* pointers to File Access Block objects. Isfd.c maintains the table
* of the pointers (isfdtab).
*
*/
#include "isam_impl.h"
static Fab *isfdtab[MAXISFD]; /* Table of pointers */
/*
* _isfd_insert(fab)
*
* Insert a pointer to an Fab object to table of ISAM file descriptors.
* Return an ISAM file descriptor, or NOISFD if the table is full.
*/
Isfd
_isfd_insert(Fab *fab)
{
Isfd i;
for (i = 0; i < MAXISFD; i++) {
if (isfdtab[i] == NULL) /* Empty entry found */
break;
}
if (i == MAXISFD)
return (NOISFD); /* isfdtab is full */
isfdtab[i] = fab;
return (i);
}
/*
* _isfd_find(isfd)
*
* Return a pointer to Fab object associated with the ISAM file
* descriptor isfd. If isfd is not a file descriptor of an open ISAM file,
* return NULL.
*/
Fab *
_isfd_find(Isfd isfd)
{
if (isfd < 0 || isfd >= MAXISFD || isfdtab[isfd] == NULL)
return (NULL);
else
return (isfdtab[isfd]);
}
/*
* _isfd_delete(isfd)
*
* Delete an entry from isfdtab. No check is made the entry exists.
*/
void
_isfd_delete(Isfd isfd)
{
if (isfd >= 0 && isfd < MAXISFD)
isfdtab[isfd] = NULL;
}