summaryrefslogtreecommitdiffstats
path: root/split.cc
blob: beecf1c1089d9402fce72ab9a513fb67aee25bc5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
/* Lziprecover - Data recovery tool for the lzip format
   Copyright (C) 2009-2021 Antonio Diaz Diaz.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#define _FILE_OFFSET_BITS 64

#include <algorithm>
#include <cerrno>
#include <climits>
#include <cstdio>
#include <cstring>
#include <string>
#include <vector>
#include <stdint.h>
#include <unistd.h>
#include <sys/stat.h>

#include "lzip.h"
#include "lzip_index.h"


namespace {

void first_filename( const std::string & input_filename,
                     const std::string & default_output_filename,
                     const int max_digits )
  {
  output_filename = default_output_filename.empty() ?
                    input_filename : default_output_filename;
  int b = output_filename.size();
  while( b > 0 && output_filename[b-1] != '/' ) --b;
  output_filename.insert( b, "rec1" );
  if( max_digits > 1 ) output_filename.insert( b + 3, max_digits - 1, '0' );
  }


bool next_filename( const int max_digits )
  {
  if( verbosity >= 1 )
    {
    std::printf( "Member '%s' done \n", output_filename.c_str() );
    std::fflush( stdout );
    }
  int b = output_filename.size();
  while( b > 0 && output_filename[b-1] != '/' ) --b;
  for( int i = b + max_digits + 2; i > b + 2; --i )	// "rec<max_digits>"
    {
    if( output_filename[i] < '9' ) { ++output_filename[i]; return true; }
    else output_filename[i] = '0';
    }
  return false;
  }

} // end namespace


int split_file( const std::string & input_filename,
                const std::string & default_output_filename, const bool force )
  {
  struct stat in_stats;
  const int infd =
    open_instream( input_filename.c_str(), &in_stats, false, true );
  if( infd < 0 ) return 1;

  Lzip_index lzip_index( infd, true, true, true, true );
  if( lzip_index.retval() != 0 )
    {
    show_file_error( input_filename.c_str(), lzip_index.error().c_str() );
    return lzip_index.retval();
    }
  // verify last member
  const Block b = lzip_index.mblock( lzip_index.members() - 1 );
  long long mpos = b.pos();
  long long msize = b.size();
  long long failure_pos = 0;
  if( !safe_seek( infd, mpos ) ) return 1;
  if( test_member_from_file( infd, msize, &failure_pos ) == 1 )
    {						// corrupt or fake trailer
    while( true )
      {
      mpos += failure_pos; msize -= failure_pos;
      if( msize < min_member_size ) break;		// trailing data
      if( !safe_seek( infd, mpos ) ) return 1;
      if( test_member_from_file( infd, msize, &failure_pos ) != 1 ) break;
      }
    lzip_index = Lzip_index( infd, true, true, true, true, mpos );
    if( lzip_index.retval() != 0 )
      {
      show_file_error( input_filename.c_str(), lzip_index.error().c_str() );
      return lzip_index.retval();
      }
    }

  if( !safe_seek( infd, 0 ) ) return 1;
  int max_digits = 1;
  for( long i = lzip_index.blocks( true ); i >= 10; i /= 10 ) ++max_digits;
  first_filename( input_filename, default_output_filename, max_digits );

  long long stream_pos = 0;		// first pos not yet written to file
  set_signal_handler();
  for( long i = 0; i < lzip_index.members(); ++i )
    {
    const Block & mb = lzip_index.mblock( i );
    if( mb.pos() > stream_pos )					// gap
      {
      if( !open_outstream( force, true, false, false ) ) return 1;
      if( !copy_file( infd, outfd, mb.pos() - stream_pos ) ||
          close_outstream( &in_stats ) != 0 )
        cleanup_and_fail( 1 );
      next_filename( max_digits );
      }
    if( !open_outstream( force, true, false, false ) ) return 1;  // member
    if( !copy_file( infd, outfd, mb.size() ) ||
        close_outstream( &in_stats ) != 0 )
      cleanup_and_fail( 1 );
    next_filename( max_digits );
    stream_pos = mb.end();
    }
  if( lzip_index.file_size() > stream_pos )		// trailing data
    {
    if( !open_outstream( force, true, false, false ) ) return 1;
    if( !copy_file( infd, outfd, lzip_index.file_size() - stream_pos ) ||
        close_outstream( &in_stats ) != 0 )
      cleanup_and_fail( 1 );
    next_filename( max_digits );
    }
  close( infd );
  return 0;
  }