diff options
Diffstat (limited to 'decoder.cc')
| -rw-r--r-- | decoder.cc | 126 |
1 files changed, 63 insertions, 63 deletions
@@ -1,5 +1,5 @@ /* Lziprecover - Data recovery tool for the lzip format - Copyright (C) 2009-2018 Antonio Diaz Diaz. + Copyright (C) 2009-2019 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 @@ -110,13 +110,13 @@ void LZ_decoder::flush_data() bool LZ_decoder::verify_trailer( const Pretty_print & pp ) const { - File_trailer trailer; - int size = rdec.read_data( trailer.data, File_trailer::size ); + Lzip_trailer trailer; + int size = rdec.read_data( trailer.data, Lzip_trailer::size ); const unsigned long long data_size = data_position(); const unsigned long long member_size = rdec.member_position(); bool error = false; - if( size < File_trailer::size ) + if( size < Lzip_trailer::size ) { error = true; if( verbosity >= 0 ) @@ -125,7 +125,7 @@ bool LZ_decoder::verify_trailer( const Pretty_print & pp ) const std::fprintf( stderr, "Trailer truncated at trailer position %d;" " some checks may fail.\n", size ); } - while( size < File_trailer::size ) trailer.data[size++] = 0; + while( size < Lzip_trailer::size ) trailer.data[size++] = 0; } const unsigned td_crc = trailer.data_crc(); @@ -214,86 +214,86 @@ int LZ_decoder::decode_member( const Pretty_print & pp ) const int pos_state = data_position() & pos_state_mask; if( rdec.decode_bit( bm_match[state()][pos_state] ) == 0 ) // 1st bit { + // literal byte Bit_model * const bm = bm_literal[get_lit_state(peek_prev())]; if( state.is_char_set_char() ) put_byte( rdec.decode_tree8( bm ) ); else put_byte( rdec.decode_matched( bm, peek( rep0 ) ) ); + continue; } - else // match or repeated match + // match or repeated match + int len; + if( rdec.decode_bit( bm_rep[state()] ) != 0 ) // 2nd bit { - int len; - if( rdec.decode_bit( bm_rep[state()] ) != 0 ) // 2nd bit + if( rdec.decode_bit( bm_rep0[state()] ) == 0 ) // 3rd bit { - if( rdec.decode_bit( bm_rep0[state()] ) == 0 ) // 3rd bit - { - if( rdec.decode_bit( bm_len[state()][pos_state] ) == 0 ) // 4th bit - { state.set_short_rep(); put_byte( peek( rep0 ) ); continue; } - } + if( rdec.decode_bit( bm_len[state()][pos_state] ) == 0 ) // 4th bit + { state.set_short_rep(); put_byte( peek( rep0 ) ); continue; } + } + else + { + unsigned distance; + if( rdec.decode_bit( bm_rep1[state()] ) == 0 ) // 4th bit + distance = rep1; else { - unsigned distance; - if( rdec.decode_bit( bm_rep1[state()] ) == 0 ) // 4th bit - distance = rep1; + if( rdec.decode_bit( bm_rep2[state()] ) == 0 ) // 5th bit + distance = rep2; else - { - if( rdec.decode_bit( bm_rep2[state()] ) == 0 ) // 5th bit - distance = rep2; - else - { distance = rep3; rep3 = rep2; } - rep2 = rep1; - } - rep1 = rep0; - rep0 = distance; + { distance = rep3; rep3 = rep2; } + rep2 = rep1; } - state.set_rep(); - len = min_match_len + rdec.decode_len( rep_len_model, pos_state ); + rep1 = rep0; + rep0 = distance; } - else // match + state.set_rep(); + len = min_match_len + rdec.decode_len( rep_len_model, pos_state ); + } + else // match + { + len = min_match_len + rdec.decode_len( match_len_model, pos_state ); + unsigned distance = rdec.decode_tree6( bm_dis_slot[get_len_state(len)] ); + if( distance >= start_dis_model ) { - len = min_match_len + rdec.decode_len( match_len_model, pos_state ); - unsigned distance = rdec.decode_tree6( bm_dis_slot[get_len_state(len)] ); - if( distance >= start_dis_model ) + const unsigned dis_slot = distance; + const int direct_bits = ( dis_slot >> 1 ) - 1; + distance = ( 2 | ( dis_slot & 1 ) ) << direct_bits; + if( dis_slot < end_dis_model ) + distance += rdec.decode_tree_reversed( + bm_dis + ( distance - dis_slot ), direct_bits ); + else { - const unsigned dis_slot = distance; - const int direct_bits = ( dis_slot >> 1 ) - 1; - distance = ( 2 | ( dis_slot & 1 ) ) << direct_bits; - if( dis_slot < end_dis_model ) - distance += rdec.decode_tree_reversed( - bm_dis + ( distance - dis_slot ), direct_bits ); - else + distance += + rdec.decode( direct_bits - dis_align_bits ) << dis_align_bits; + distance += rdec.decode_tree_reversed4( bm_align ); + if( distance == 0xFFFFFFFFU ) // marker found { - distance += - rdec.decode( direct_bits - dis_align_bits ) << dis_align_bits; - distance += rdec.decode_tree_reversed4( bm_align ); - if( distance == 0xFFFFFFFFU ) // marker found + rdec.normalize(); + flush_data(); + if( len == min_match_len ) // End Of Stream marker + { + if( verify_trailer( pp ) ) return 0; else return 3; + } + if( len == min_match_len + 1 ) // Sync Flush marker + { + rdec.load(); continue; + } + if( verbosity >= 0 ) { - rdec.normalize(); - flush_data(); - if( len == min_match_len ) // End Of Stream marker - { - if( verify_trailer( pp ) ) return 0; else return 3; - } - if( len == min_match_len + 1 ) // Sync Flush marker - { - rdec.load(); continue; - } - if( verbosity >= 0 ) - { - pp(); - std::fprintf( stderr, "Unsupported marker code '%d'\n", len ); - } - return 4; + pp(); + std::fprintf( stderr, "Unsupported marker code '%d'\n", len ); } + return 4; } } - rep3 = rep2; rep2 = rep1; rep1 = rep0; rep0 = distance; - state.set_match(); - if( rep0 >= dictionary_size || ( rep0 >= pos && !pos_wrapped ) ) - { flush_data(); return 1; } } - copy_block( rep0, len ); + rep3 = rep2; rep2 = rep1; rep1 = rep0; rep0 = distance; + state.set_match(); + if( rep0 >= dictionary_size || ( rep0 >= pos && !pos_wrapped ) ) + { flush_data(); return 1; } } + copy_block( rep0, len ); } flush_data(); return 2; |