newlib/winsup/cygwin/fhandler_floppy.cc
Corinna Vinschen ae9b22c69b * fhandler.cc (fhandler_base::open): Always add GENERIC_READ access
when opening raw disk devices.
        * fhandler_floppy.cc (fhandler_dev_floppy::lseek): Implement bytewise
        access.
        * fhandler_raw.cc (fhandler_dev_raw::open): Always open raw disk device
        binary.
        (fhandler_dev_raw::raw_write): Don't drop read buffer content when
        writing after read.
2001-02-05 16:10:06 +00:00

165 lines
3.4 KiB
C++

/* fhandler_floppy.cc. See fhandler.h for a description of the
fhandler classes.
Copyright 1999, 2000 Cygnus Solutions.
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#include "winsup.h"
#include <sys/termios.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include "fhandler.h"
#include "cygerrno.h"
/**********************************************************************/
/* fhandler_dev_floppy */
int
fhandler_dev_floppy::is_eom (int win_error)
{
int ret = (win_error == ERROR_INVALID_PARAMETER);
if (ret)
debug_printf ("end of medium");
return ret;
}
int
fhandler_dev_floppy::is_eof (int)
{
int ret = 0;
if (ret)
debug_printf ("end of file");
return ret;
}
fhandler_dev_floppy::fhandler_dev_floppy (const char *name, int unit) : fhandler_dev_raw (FH_FLOPPY, name, unit)
{
set_cb (sizeof *this);
}
int
fhandler_dev_floppy::open (const char *path, int flags, mode_t)
{
/* The correct size of the buffer would be 512 bytes,
* which is the atomic size, supported by WinNT.
* Unfortunately, the performance is worse than
* access to file system on same device!
* Setting buffer size to a relatively big value
* increases performance by means.
* The new ioctl call with 'rdevio.h' header file
* supports changing this value.
*
* Let's be smart: Let's take a multiplier of typical tar
* and cpio buffer sizes by default!
*/
devbufsiz = 61440L; /* 512L; */
return fhandler_dev_raw::open (path, flags);
}
int
fhandler_dev_floppy::close (void)
{
int ret;
ret = writebuf ();
if (ret)
{
fhandler_dev_raw::close ();
return ret;
}
return fhandler_dev_raw::close ();
}
off_t
fhandler_dev_floppy::lseek (off_t offset, int whence)
{
int ret;
DWORD off;
char buf[512];
if (whence == SEEK_SET)
{
if (offset < 0)
{
set_errno (EINVAL);
return -1;
}
/* Invalidate buffer. */
ret = writebuf ();
if (ret)
return ret;
devbufstart = devbufend = 0;
off = (offset / 512) * 512;
if (SetFilePointer (get_handle (), off, NULL, FILE_BEGIN)
== INVALID_SET_FILE_POINTER)
{
__seterrno ();
return -1;
}
return raw_read (buf, offset - off);
}
else if (whence == SEEK_CUR)
{
DWORD low;
LONG high = 0;
low = SetFilePointer (get_handle (), 0, &high, FILE_CURRENT);
if (low == INVALID_SET_FILE_POINTER && GetLastError ())
{
__seterrno ();
return -1;
}
long long cur = (long long) high << 32 + low;
if (is_writing)
cur += devbufend - devbufstart;
else
cur -= devbufend - devbufstart;
/* Invalidate buffer. */
ret = writebuf ();
if (ret)
return ret;
devbufstart = devbufend = 0;
cur += offset;
if (cur < 0)
{
set_errno (EINVAL);
return -1;
}
long long set = (cur / 512) * 512;
high = set >> 32;
low = set & 0xffffffff;
off = cur - set;
low = SetFilePointer (get_handle (), low, &high, FILE_BEGIN);
if (low == INVALID_SET_FILE_POINTER && GetLastError ())
{
__seterrno ();
return -1;
}
return raw_read (buf, off);
}
/* SEEK_END is not supported on raw disk devices. */
set_errno (EINVAL);
return -1;
}
int
fhandler_dev_floppy::ioctl (unsigned int cmd, void *buf)
{
return fhandler_dev_raw::ioctl (cmd, buf);
}