summaryrefslogtreecommitdiffstats
path: root/decoder.cc
diff options
context:
space:
mode:
Diffstat (limited to 'decoder.cc')
-rw-r--r--decoder.cc56
1 files changed, 24 insertions, 32 deletions
diff --git a/decoder.cc b/decoder.cc
index 8c163d5..734fc9d 100644
--- a/decoder.cc
+++ b/decoder.cc
@@ -1,5 +1,5 @@
/* Lziprecover - Data recovery tool for the lzip format
- Copyright (C) 2009-2016 Antonio Diaz Diaz.
+ Copyright (C) 2009-2017 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
@@ -181,7 +181,7 @@ bool LZ_decoder::verify_trailer( const Pretty_print & pp ) const
( 8.0 * member_size ) / data_size,
100.0 * ( 1.0 - ( (double)member_size / data_size ) ) );
if( !error && verbosity >= 4 )
- std::fprintf( stderr, "data CRC %08X, data size %9llu, member size %8llu. ",
+ std::fprintf( stderr, "CRC %08X, decompressed %9llu, compressed %8llu. ",
crc(), data_size, member_size );
if( rdec.get_code() != 0 && !error && verbosity >= 1 )
{ // corruption in the last 4 bytes of the EOS marker
@@ -204,7 +204,7 @@ int LZ_decoder::decode_member( const Pretty_print & pp )
Bit_model bm_rep2[State::states];
Bit_model bm_len[State::states][pos_states];
Bit_model bm_dis_slot[len_states][1<<dis_slot_bits];
- Bit_model bm_dis[modeled_distances-end_dis_model];
+ Bit_model bm_dis[modeled_distances-end_dis_model+1];
Bit_model bm_align[dis_align_size];
Len_model match_len_model;
Len_model rep_len_model;
@@ -220,25 +220,23 @@ 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
{
- const uint8_t prev_byte = peek_prev();
- if( state.is_char() )
- {
- state.set_char1();
- put_byte( rdec.decode_tree8( bm_literal[get_lit_state(prev_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
- {
- state.set_char2();
- put_byte( rdec.decode_matched( bm_literal[get_lit_state(prev_byte)],
- peek( rep0 ) ) );
- }
+ put_byte( rdec.decode_matched( bm, peek( rep0 ) ) );
}
else // match or repeated match
{
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; }
+ }
+ else
{
unsigned distance;
if( rdec.decode_bit( bm_rep1[state()] ) == 0 ) // 4th bit
@@ -254,34 +252,28 @@ int LZ_decoder::decode_member( const Pretty_print & pp )
rep1 = rep0;
rep0 = distance;
}
- else
- {
- if( rdec.decode_bit( bm_len[state()][pos_state] ) == 0 ) // 4th bit
- { state.set_short_rep(); put_byte( peek( rep0 ) ); continue; }
- }
state.set_rep();
len = min_match_len + rdec.decode_len( rep_len_model, pos_state );
}
else // match
{
- const unsigned rep0_saved = rep0;
len = min_match_len + rdec.decode_len( match_len_model, pos_state );
- const int dis_slot = rdec.decode_tree6( bm_dis_slot[get_len_state(len)] );
- if( dis_slot < start_dis_model ) rep0 = dis_slot;
- else
+ 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;
- rep0 = ( 2 | ( dis_slot & 1 ) ) << direct_bits;
+ distance = ( 2 | ( dis_slot & 1 ) ) << direct_bits;
if( dis_slot < end_dis_model )
- rep0 += rdec.decode_tree_reversed( bm_dis + rep0 - dis_slot - 1,
- direct_bits );
+ distance += rdec.decode_tree_reversed(
+ bm_dis + ( distance - dis_slot ), direct_bits );
else
{
- rep0 += rdec.decode( direct_bits - dis_align_bits ) << dis_align_bits;
- rep0 += rdec.decode_tree_reversed4( bm_align );
- if( rep0 == 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
{
- rep0 = rep0_saved;
rdec.normalize();
flush_data();
if( len == min_match_len ) // End Of Stream marker
@@ -301,7 +293,7 @@ int LZ_decoder::decode_member( const Pretty_print & pp )
}
}
}
- rep3 = rep2; rep2 = rep1; rep1 = rep0_saved;
+ rep3 = rep2; rep2 = rep1; rep1 = rep0; rep0 = distance;
state.set_match();
if( rep0 >= dictionary_size || ( rep0 >= pos && !pos_wrapped ) )
{ flush_data(); return 1; }