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-rw-r--r--range_dec.cc359
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+/* Lziprecover - Data recovery tool for lzipped files
+ Copyright (C) 2009, 2010, 2011 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 3 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 <cstdlib>
+#include <cstring>
+#include <string>
+#include <vector>
+#include <stdint.h>
+#include <unistd.h>
+#include <sys/stat.h>
+
+#include "lzip.h"
+#include "decoder.h"
+
+
+namespace {
+
+class Member
+ {
+ Block dblock_, mblock_; // data block, member block
+
+public:
+ Member( const long long dp, const long long ds,
+ const long long mp, const long long ms )
+ : dblock_( dp, ds ), mblock_( mp, ms ) {}
+
+ const Block & dblock() const throw() { return dblock_; }
+ Block & dblock() throw() { return dblock_; }
+ const Block & mblock() const throw() { return mblock_; }
+ Block & mblock() throw() { return mblock_; }
+ };
+
+
+int seek_read( const int fd, uint8_t * const buf, const int size,
+ const long long pos ) throw()
+ {
+ if( lseek( fd, pos, SEEK_SET ) == pos )
+ return readblock( fd, buf, size );
+ return 0;
+ }
+
+
+class Member_index
+ {
+ std::vector< Member > member_vector;
+
+public:
+ Member_index( const int infd, const long long isize )
+ {
+ long long pos = isize; // always points to a header or EOF
+ File_header header;
+ File_trailer trailer;
+ while( pos >= min_member_size )
+ {
+ if( seek_read( infd, trailer.data, File_trailer::size(),
+ pos - File_trailer::size() ) != File_trailer::size() )
+ { show_error( "Read error", errno ); std::exit( 1 ); }
+ const long long member_size = trailer.member_size();
+ if( member_size < min_member_size || pos < member_size ) break;
+ if( seek_read( infd, header.data, File_header::size,
+ pos - member_size ) != File_header::size )
+ { show_error( "Read error", errno ); std::exit( 1 ); }
+ if( !header.verify_magic() || !header.verify_version() ) break;
+ pos -= member_size;
+ member_vector.push_back( Member( 0, trailer.data_size(),
+ pos, member_size ) );
+ }
+ if( pos != 0 || member_vector.size() == 0 )
+ {
+ show_error( "Member size in input file trailer is corrupt." );
+ std::exit( 1 );
+ }
+ std::reverse( member_vector.begin(), member_vector.end() );
+ for( unsigned int i = 0; i < member_vector.size() - 1; ++i )
+ member_vector[i+1].dblock().pos( member_vector[i].dblock().end() );
+ }
+
+ long long data_end() const throw()
+ { if( member_vector.size() ) return member_vector.back().dblock().end();
+ else return 0; }
+
+ const Member & member( const int i ) const throw()
+ { return member_vector[i]; }
+ const Block & dblock( const int i ) const throw()
+ { return member_vector[i].dblock(); }
+ const Block & mblock( const int i ) const throw()
+ { return member_vector[i].mblock(); }
+ int members() const throw() { return (int)member_vector.size(); }
+ };
+
+
+// Returns the number of chars read, or 0 if error.
+//
+int parse_long_long( const char * const ptr, long long & value ) throw()
+ {
+ char * tail;
+ int c = 0;
+ errno = 0;
+ value = strtoll( ptr, &tail, 0 );
+ if( tail == ptr || errno ) return 0;
+ c = tail - ptr;
+
+ if( ptr[c] )
+ {
+ const int factor = ( ptr[c+1] == 'i' ) ? 1024 : 1000;
+ int exponent = 0;
+ switch( ptr[c] )
+ {
+ case 'Y': exponent = 8; break;
+ case 'Z': exponent = 7; break;
+ case 'E': exponent = 6; break;
+ case 'P': exponent = 5; break;
+ case 'T': exponent = 4; break;
+ case 'G': exponent = 3; break;
+ case 'M': exponent = 2; break;
+ case 'K': if( factor == 1024 ) exponent = 1; break;
+ case 'k': if( factor == 1000 ) exponent = 1; break;
+ }
+ if( exponent > 0 )
+ {
+ ++c;
+ if( ptr[c] == 'i' ) { ++c; if( value ) format_num( 0, 0, -1 ); }
+ if( ptr[c] == 'B' ) ++c;
+ for( int i = 0; i < exponent; ++i )
+ {
+ if( LLONG_MAX / factor >= llabs( value ) ) value *= factor;
+ else return 0;
+ }
+ }
+ }
+ return c;
+ }
+
+
+// Recognized formats: <begin> <begin>-<end> <begin>,<size>
+//
+void parse_range( const char * const ptr, Block & range ) throw()
+ {
+ long long value = 0;
+ int c = parse_long_long( ptr, value ); // pos
+ if( c && value >= 0 && value < LLONG_MAX &&
+ ( ptr[c] == 0 || ptr[c] == ',' || ptr[c] == '-' ) )
+ {
+ range.pos( value );
+ if( ptr[c] == 0 ) { range.size( LLONG_MAX - value ); return; }
+ const bool issize = ( ptr[c] == ',' );
+ c = parse_long_long( ptr + c + 1, value ); // size
+ if( c && value > 0 && ( issize || value > range.pos() ) )
+ {
+ if( !issize ) value -= range.pos();
+ if( LLONG_MAX - range.pos() >= value ) { range.size( value ); return; }
+ }
+ }
+ show_error( "Bad decompression range.", 0, true );
+ std::exit( 1 );
+ }
+
+
+bool safe_seek( const int fd, const long long pos ) throw()
+ {
+ if( lseek( fd, pos, SEEK_SET ) == pos ) return true;
+ show_error( "Seek error", errno ); return false;
+ }
+
+
+int decompress_member( const int infd, const int outfd,
+ const Pretty_print & pp, const Member & member,
+ const long long outskip, const long long outend )
+ {
+ int retval = 0;
+
+ try {
+ Range_decoder rdec( infd );
+ File_header header;
+ int size;
+ for( size = 0; size < File_header::size && !rdec.finished(); ++size )
+ header.data[size] = rdec.get_byte();
+ if( rdec.finished() ) // End Of File
+ { pp( "Error reading member header" ); retval = 1; }
+ if( !header.verify_magic() )
+ { pp( "Bad magic number (file not in lzip format)" ); retval = 2; }
+ if( !header.verify_version() )
+ {
+ if( verbosity >= 0 )
+ { pp();
+ std::fprintf( stderr, "Version %d member format not supported.\n",
+ header.version() ); }
+ retval = 2;
+ }
+ if( header.dictionary_size() < min_dictionary_size ||
+ header.dictionary_size() > max_dictionary_size )
+ { pp( "Invalid dictionary size in member header" ); retval = 2; }
+
+ if( pp.verbosity() >= 2 )
+ {
+ pp();
+ std::fprintf( stderr, "version %d, dictionary size %7sB. ",
+ header.version(),
+ format_num( header.dictionary_size(), 9999, -1 ) );
+ }
+ LZ_decoder decoder( header, rdec, outfd, outskip, outend );
+
+ const int result = decoder.decode_member( pp );
+ if( result != 0 )
+ {
+ if( verbosity >= 0 && result <= 2 )
+ {
+ pp();
+ if( result == 2 )
+ std::fprintf( stderr, "File ends unexpectedly at pos %lld\n",
+ member.mblock().pos() + rdec.member_position() );
+ else
+ std::fprintf( stderr, "Decoder error at pos %lld\n",
+ member.mblock().pos() + rdec.member_position() );
+ }
+ retval = 2;
+ }
+ if( pp.verbosity() >= 2 ) std::fprintf( stderr, "done\n" );
+ }
+ catch( std::bad_alloc )
+ {
+ pp( "Not enough memory. Find a machine with more memory" );
+ retval = 1;
+ }
+ catch( Error e ) { pp(); show_error( e.msg, errno ); retval = 1; }
+ return retval;
+ }
+
+} // end namespace
+
+
+int list_file( const std::string & input_filename )
+ {
+ struct stat in_stats;
+ const int infd = open_instream( input_filename, &in_stats, true, true );
+ if( infd < 0 ) return 1;
+ const long long isize = lseek( infd, 0, SEEK_END );
+ if( isize < 0 )
+ { show_error( "Input file is not seekable", errno ); return 1; }
+ if( isize < min_member_size )
+ { show_error( "Input file is too short." ); return 2; }
+
+ Member_index member_index( infd, isize );
+
+ if( verbosity >= 0 )
+ {
+ if( verbosity >= 1 )
+ {
+ std::printf( "Total members in file = %d.\n", member_index.members() );
+ for( int i = 0; i < member_index.members(); ++i )
+ {
+ const Block & db = member_index.dblock( i );
+ const Block & mb = member_index.mblock( i );
+ std::printf( "Member %3d data pos %9lld data size %7lld "
+ "member pos %9lld member size %7lld.\n", i,
+ db.pos(), db.size(), mb.pos(), mb.size() );
+ }
+ std::printf( "\n" );
+ }
+
+ const long long data_size = member_index.data_end();
+ if( data_size > 0 && isize > 0 )
+ std::printf( "%6.3f:1, %6.3f bits/byte, %5.2f%% saved.\n",
+ (double)data_size / isize,
+ ( 8.0 * isize ) / data_size,
+ 100.0 * ( 1.0 - ( (double)isize / data_size ) ) );
+ std::printf( "decompressed size %9lld, compressed size %8lld.\n",
+ data_size, isize );
+ }
+ return 0;
+ }
+
+
+int range_decompress( const std::string & input_filename,
+ const std::string & output_filename,
+ const std::string & range_string,
+ const bool to_stdout, const bool force )
+ {
+ Block range( 0, 0 );
+ parse_range( range_string.c_str(), range );
+ struct stat in_stats;
+ const int infd = open_instream( input_filename, &in_stats, true, true );
+ if( infd < 0 ) return 1;
+ const long long isize = lseek( infd, 0, SEEK_END );
+ if( isize < 0 )
+ { show_error( "Input file is not seekable", errno ); return 1; }
+ if( isize < min_member_size )
+ { show_error( "Input file is too short." ); return 2; }
+
+ Member_index member_index( infd, isize );
+ if( range.end() > member_index.data_end() )
+ range.size( std::max( 0LL, member_index.data_end() - range.pos() ) );
+ if( range.size() <= 0 )
+ { if( verbosity >= 1 ) show_error( "Nothing to do." ); return 0; }
+
+ if( verbosity >= 1 )
+ {
+ if( verbosity >= 2 )
+ std::fprintf( stderr, "Decompressed file size = %sB\n",
+ format_num( member_index.data_end() ) );
+ std::fprintf( stderr, "Decompressing range %sB", format_num( range.pos() ) );
+ std::fprintf( stderr, " to %sB ", format_num( range.pos() + range.size() ) );
+ std::fprintf( stderr, "(%sBytes)\n", format_num( range.size() ) );
+ }
+
+ int outfd = -1;
+ if( to_stdout || !output_filename.size() )
+ outfd = STDOUT_FILENO;
+ else
+ { outfd = open_outstream_rw( output_filename, force );
+ if( outfd < 0 ) return 1; }
+ Pretty_print pp( input_filename, 0 );
+ int retval = 0;
+ for( int i = 0; i < member_index.members(); ++i )
+ {
+ const Block & db = member_index.dblock( i );
+ if( range.overlaps( db ) )
+ {
+ if( verbosity >= 3 )
+ std::fprintf( stderr, "Decompressing member %3d\n", i );
+ const long long outskip = std::max( 0LL, range.pos() - db.pos() );
+ const long long outend = std::min( db.end(), range.end() - db.pos() );
+ if( !safe_seek( infd, member_index.mblock( i ).pos() ) )
+ { retval = 1; break; }
+ retval = decompress_member( infd, outfd, pp, member_index.member( i ),
+ outskip, outend );
+ if( retval ) cleanup_and_fail( output_filename, outfd, retval );
+ pp.reset();
+ }
+ }
+ if( close( outfd ) != 0 )
+ {
+ show_error( "Error closing output file", errno );
+ cleanup_and_fail( output_filename, -1, 1 );
+ }
+ if( verbosity >= 2 )
+ std::fprintf( stderr, "Byte range decompressed successfully.\n" );
+ return retval;
+ }