1/*  Copyright 1999-2003,2006,2008,2009 Alain Knaff.
2 *  This file is part of mtools.
3 *
4 *  Mtools is free software: you can redistribute it and/or modify
5 *  it under the terms of the GNU General Public License as published by
6 *  the Free Software Foundation, either version 3 of the License, or
7 *  (at your option) any later version.
8 *
9 *  Mtools is distributed in the hope that it will be useful,
10 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
11 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 *  GNU General Public License for more details.
13 *
14 *  You should have received a copy of the GNU General Public License
15 *  along with Mtools.  If not, see <http://www.gnu.org/licenses/>.
16 */
17
18#include "sysincludes.h"
19#include "stream.h"
20#include "fsP.h"
21#include "llong.h"
22#include "mtools.h"
23
24#if 1
25const mt_off_t max_off_t_31 = MAX_OFF_T_B(31); /* Floppyd */
26const mt_off_t max_off_t_32 = MAX_OFF_T_B(32); /* Directory */
27const mt_off_t max_off_t_41 = MAX_OFF_T_B(41); /* SCSI */
28const mt_off_t max_off_t_seek = MAX_OFF_T_B(SEEK_BITS); /* SCSI */
29#else
30const mt_off_t max_off_t_31 = MAX_OFF_T_B(10); /* Floppyd */
31const mt_off_t max_off_t_41 = MAX_OFF_T_B(10); /* SCSI */
32const mt_off_t max_off_t_seek = MAX_OFF_T_B(10); /* SCSI */
33#endif
34
35int fileTooBig(mt_off_t off) {
36	return (off & ~max_off_t_32) != 0;
37}
38
39off_t truncBytes32(mt_off_t off)
40{
41	if (fileTooBig(off)) {
42		fprintf(stderr, "Internal error, offset too big\n");
43		exit(1);
44	}
45	return (off_t) off;
46}
47
48mt_off_t sectorsToBytes(Stream_t *Stream, off_t off)
49{
50	DeclareThis(Fs_t);
51	return (mt_off_t) off << This->sectorShift;
52}
53
54#if defined HAVE_LLSEEK
55# ifndef HAVE_LLSEEK_PROTOTYPE
56extern long long llseek (int fd, long long offset, int origin);
57# endif
58#endif
59
60#if defined HAVE_LSEEK64
61# ifndef HAVE_LSEEK64_PROTOTYPE
62extern long long lseek64 (int fd, long long offset, int origin);
63# endif
64#endif
65
66
67int mt_lseek(int fd, mt_off_t where, int whence)
68{
69#if defined HAVE_LSEEK64
70	if(lseek64(fd, where, whence) >= 0)
71		return 0;
72	else
73		return -1;
74#elif defined HAVE_LLSEEK
75	if(llseek(fd, where, whence) >= 0)
76		return 0;
77	else
78		return -1;
79#else
80	if (lseek(fd, (off_t) where, whence) >= 0)
81		return 0;
82	else
83		return 1;
84#endif
85}
86
87unsigned int log_2(int size)
88{
89	unsigned int i;
90
91	for(i=0; i<24; i++) {
92		if(1 << i == size)
93			return i;
94	}
95	return 24;
96}
97