minix/commands/i386/mtools-3.9.7/llong.c
2005-04-21 14:53:53 +00:00

84 lines
1.8 KiB
C
Executable file

#include "sysincludes.h"
#include "stream.h"
#include "fsP.h"
#include "llong.h"
#include "mtools.h"
/* Warnings about integer overflow in expression can be ignored. These are
* due to the way that maximal values for those integers are computed:
* intentional overflow from smallest negative number (1000...) to highest
* positive number (0111...) by substraction of 1 */
#ifdef __GNUC__
/*
#warning "The following warnings about integer overflow in expression can be safely ignored"
*/
#endif
#if 1
const mt_off_t max_off_t_31 = MAX_OFF_T_B(31); /* Floppyd */
const mt_off_t max_off_t_41 = MAX_OFF_T_B(41); /* SCSI */
const mt_off_t max_off_t_seek = MAX_OFF_T_B(SEEK_BITS); /* SCSI */
#else
const mt_off_t max_off_t_31 = MAX_OFF_T_B(10); /* Floppyd */
const mt_off_t max_off_t_41 = MAX_OFF_T_B(10); /* SCSI */
const mt_off_t max_off_t_seek = MAX_OFF_T_B(10); /* SCSI */
#endif
off_t truncBytes32(mt_off_t off)
{
if (off & ~max_off_t_31) {
fprintf(stderr, "Internal error, offset too big\n");
exit(1);
}
return (off_t) off;
}
mt_off_t sectorsToBytes(Stream_t *Stream, off_t off)
{
DeclareThis(Fs_t);
return (mt_off_t) off << This->sectorShift;
}
#if defined HAVE_LLSEEK
# ifndef HAVE_LLSEEK_PROTOTYPE
extern long long llseek (int fd, long long offset, int origin);
# endif
#endif
#if defined HAVE_LSEEK64
# ifndef HAVE_LSEEK64_PROTOTYPE
extern long long lseek64 (int fd, long long offset, int origin);
# endif
#endif
int mt_lseek(int fd, mt_off_t where, int whence)
{
#if defined HAVE_LSEEK64
if(lseek64(fd, where, whence) >= 0)
return 0;
else
return -1;
#elif defined HAVE_LLSEEK
if(llseek(fd, where, whence) >= 0)
return 0;
else
return -1;
#else
if (lseek(fd, (off_t) where, whence) >= 0)
return 0;
else
return 1;
#endif
}
int log_2(int size)
{
int i;
for(i=0; i<24; i++) {
if(1 << i == size)
return i;
}
return 24;
}