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Diffstat (limited to 'split.cc')
| -rw-r--r-- | split.cc | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/split.cc b/split.cc new file mode 100644 index 0000000..48d7915 --- /dev/null +++ b/split.cc @@ -0,0 +1,142 @@ +/* Lziprecover - Data recovery tool for the lzip format + Copyright (C) 2009-2024 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 { + +bool first_filename( const std::string & input_filename, + const std::string & default_output_filename, + const int max_digits ) + { + const bool to_file = default_output_filename.size(); + output_filename = to_file ? default_output_filename : input_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' ); + return to_file; + } + + +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 Cl_options & cl_opts, const bool force ) + { + const char * const filename = input_filename.c_str(); + struct stat in_stats; + const int infd = open_instream( filename, &in_stats, false, true ); + if( infd < 0 ) return 1; + + Lzip_index lzip_index( infd, cl_opts, true, true ); + if( lzip_index.retval() != 0 ) + { + show_file_error( filename, lzip_index.error().c_str() ); + return lzip_index.retval(); + } + // check 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, filename ) ) 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, filename ) ) return 1; + if( test_member_from_file( infd, msize, &failure_pos ) != 1 ) break; + } + lzip_index = Lzip_index( infd, cl_opts, true, true, mpos ); + if( lzip_index.retval() != 0 ) + { + show_file_error( filename, lzip_index.error().c_str() ); + return lzip_index.retval(); + } + } + + if( !safe_seek( infd, 0, filename ) ) return 1; + int max_digits = 1; + for( long i = lzip_index.blocks( true ); i >= 10; i /= 10 ) ++max_digits; + bool to_file = // if true, create intermediate dirs + 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, to_file ) ) return 1; + if( !copy_file( infd, outfd, mb.pos() - stream_pos ) || + !close_outstream( &in_stats ) ) cleanup_and_fail( 1 ); + next_filename( max_digits ); to_file = false; + } + if( !open_outstream( force, true, false, false, to_file ) ) return 1; // member + if( !copy_file( infd, outfd, mb.size() ) || + !close_outstream( &in_stats ) ) cleanup_and_fail( 1 ); + next_filename( max_digits ); to_file = false; + stream_pos = mb.end(); + } + if( lzip_index.file_size() > stream_pos ) // trailing data + { + if( !open_outstream( force, true, false, false, to_file ) ) return 1; + if( !copy_file( infd, outfd, lzip_index.file_size() - stream_pos ) || + !close_outstream( &in_stats ) ) cleanup_and_fail( 1 ); + next_filename( max_digits ); to_file = false; + } + close( infd ); + return 0; + } |