85 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			85 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;
 | |
| }
 | 
