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