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/* Lunzip - Decompressor for lzip files
Copyright (C) 2010 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 <errno.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "lunzip.h"
#include "decoder.h"
CRC32 crc32;
bool Rd_read_block( struct Range_decoder * const rdec )
{
if( !rdec->at_stream_end )
{
rdec->stream_pos = readblock( rdec->infd, rdec->buffer, rd_buffer_size );
if( rdec->stream_pos != rd_buffer_size && errno )
{ show_error( "Read error", errno, false ); cleanup_and_fail( 1 ); }
rdec->at_stream_end = ( rdec->stream_pos < rd_buffer_size );
rdec->partial_member_pos += rdec->pos;
rdec->pos = 0;
}
return rdec->pos < rdec->stream_pos;
}
void LZd_flush_data( struct LZ_decoder * const decoder )
{
const int size = decoder->pos - decoder->stream_pos;
if( size > 0 )
{
CRC32_update_buf( &decoder->crc_, decoder->buffer + decoder->stream_pos, size );
if( decoder->outfd >= 0 &&
writeblock( decoder->outfd, decoder->buffer + decoder->stream_pos, size ) != size )
{ show_error( "write error", errno, false ); cleanup_and_fail( 1 ); }
if( decoder->pos >= decoder->buffer_size )
{ decoder->partial_data_pos += decoder->pos; decoder->pos = 0; }
decoder->stream_pos = decoder->pos;
}
}
bool LZd_verify_trailer( struct LZ_decoder * const decoder,
struct Pretty_print * const pp )
{
int i;
File_trailer trailer;
const int trailer_size = Ft_versioned_size( decoder->member_version );
const long long member_size =
Rd_member_position( decoder->range_decoder ) + trailer_size;
bool error = false;
for( i = 0; i < trailer_size && !error; ++i )
{
if( !Rd_finished( decoder->range_decoder ) )
trailer[i] = Rd_get_byte( decoder->range_decoder );
else
{
error = true;
if( pp->verbosity >= 0 )
{
Pp_show_msg( pp, 0 );
fprintf( stderr, "Trailer truncated at trailer position %d;"
" some checks may fail.\n", i );
}
for( ; i < trailer_size; ++i ) trailer[i] = 0;
}
}
if( decoder->member_version == 0 ) Ft_set_member_size( trailer, member_size );
if( !Rd_code_is_zero( decoder->range_decoder ) )
{
error = true;
Pp_show_msg( pp, "Range decoder final code is not zero" );
}
if( Ft_get_data_crc( trailer ) != LZd_crc( decoder ) )
{
error = true;
if( pp->verbosity >= 0 )
{
Pp_show_msg( pp, 0 );
fprintf( stderr, "CRC mismatch; trailer says %08X, data CRC is %08X.\n",
(unsigned int)Ft_get_data_crc( trailer ),
(unsigned int)LZd_crc( decoder ) );
}
}
if( Ft_get_data_size( trailer ) != LZd_data_position( decoder ) )
{
error = true;
if( pp->verbosity >= 0 )
{
Pp_show_msg( pp, 0 );
fprintf( stderr, "Data size mismatch; trailer says %lld, data size is %lld (0x%llX).\n",
Ft_get_data_size( trailer ), LZd_data_position( decoder ), LZd_data_position( decoder ) );
}
}
if( Ft_get_member_size( trailer ) != member_size )
{
error = true;
if( pp->verbosity >= 0 )
{
Pp_show_msg( pp, 0 );
fprintf( stderr, "Member size mismatch; trailer says %lld, member size is %lld (0x%llX).\n",
Ft_get_member_size( trailer ), member_size, member_size );
}
}
if( !error && pp->verbosity >= 4 && LZd_data_position( decoder ) > 0 && member_size > 0 )
fprintf( stderr, "%6.3f:1, %6.3f bits/byte, %5.2f%% saved. ",
(double)LZd_data_position( decoder ) / member_size,
( 8.0 * member_size ) / LZd_data_position( decoder ),
100.0 * ( 1.0 - ( (double)member_size / LZd_data_position( decoder ) ) ) );
if( !error && pp->verbosity >= 3 )
fprintf( stderr, "data CRC %08X, data size %9lld, member size %8lld. ",
(unsigned int)Ft_get_data_crc( trailer ),
Ft_get_data_size( trailer ), Ft_get_member_size( trailer ) );
return !error;
}
/* Return value: 0 = OK, 1 = decoder error, 2 = unexpected EOF,
3 = trailer error, 4 = unknown marker found. */
int LZd_decode_member( struct LZ_decoder * const decoder,
struct Pretty_print * const pp )
{
unsigned int rep0 = 0; /* rep[0-3] latest four distances */
unsigned int rep1 = 0; /* used for efficient coding of */
unsigned int rep2 = 0; /* repeated distances */
unsigned int rep3 = 0;
State state = 0;
Rd_load( decoder->range_decoder );
while( true )
{
const int pos_state = LZd_data_position( decoder ) & pos_state_mask;
if( Rd_finished( decoder->range_decoder ) )
{ LZd_flush_data( decoder ); return 2; }
if( Rd_decode_bit( decoder->range_decoder, &decoder->bm_match[state][pos_state] ) == 0 )
{
const uint8_t prev_byte = LZd_get_prev_byte( decoder );
if( St_is_char( state ) )
LZd_put_byte( decoder, Lid_decode( &decoder->literal_decoder,
decoder->range_decoder, prev_byte ) );
else
LZd_put_byte( decoder, Lid_decode_matched( &decoder->literal_decoder,
decoder->range_decoder, prev_byte, LZd_get_byte( decoder, rep0 ) ) );
St_set_char( &state );
}
else
{
int len;
if( Rd_decode_bit( decoder->range_decoder, &decoder->bm_rep[state] ) == 1 )
{
len = 0;
if( Rd_decode_bit( decoder->range_decoder, &decoder->bm_rep0[state] ) == 1 )
{
unsigned int distance;
if( Rd_decode_bit( decoder->range_decoder, &decoder->bm_rep1[state] ) == 0 )
distance = rep1;
else
{
if( Rd_decode_bit( decoder->range_decoder, &decoder->bm_rep2[state] ) == 0 )
distance = rep2;
else { distance = rep3; rep3 = rep2; }
rep2 = rep1;
}
rep1 = rep0;
rep0 = distance;
}
else
{
if( Rd_decode_bit( decoder->range_decoder, &decoder->bm_len[state][pos_state] ) == 0 )
{ St_set_short_rep( &state ); len = 1; }
}
if( len == 0 )
{
St_set_rep( &state );
len = min_match_len + Led_decode( &decoder->rep_match_len_decoder, decoder->range_decoder, pos_state );
}
}
else
{
int dis_slot;
const unsigned int rep0_saved = rep0;
len = min_match_len + Led_decode( &decoder->len_decoder, decoder->range_decoder, pos_state );
dis_slot = Rd_decode_tree( decoder->range_decoder, decoder->bm_dis_slot[get_dis_state(len)], dis_slot_bits );
if( dis_slot < start_dis_model ) rep0 = dis_slot;
else
{
const int direct_bits = ( dis_slot >> 1 ) - 1;
rep0 = ( 2 | ( dis_slot & 1 ) ) << direct_bits;
if( dis_slot < end_dis_model )
rep0 += Rd_decode_tree_reversed( decoder->range_decoder, decoder->bm_dis + rep0 - dis_slot, direct_bits );
else
{
rep0 += Rd_decode( decoder->range_decoder, direct_bits - dis_align_bits ) << dis_align_bits;
rep0 += Rd_decode_tree_reversed( decoder->range_decoder, decoder->bm_align, dis_align_bits );
if( rep0 == 0xFFFFFFFFU ) /* Marker found */
{
rep0 = rep0_saved;
Rd_normalize( decoder->range_decoder );
LZd_flush_data( decoder );
if( len == min_match_len ) /* End Of Stream marker */
{
if( LZd_verify_trailer( decoder, pp ) ) return 0; else return 3;
}
if( len == min_match_len + 1 ) /* Sync Flush marker */
{
Rd_load( decoder->range_decoder ); continue;
}
if( pp->verbosity >= 0 )
{
Pp_show_msg( pp, 0 );
fprintf( stderr, "Unsupported marker code `%d'.\n", len );
}
return 4;
}
}
}
rep3 = rep2; rep2 = rep1; rep1 = rep0_saved;
St_set_match( &state );
if( rep0 >= (unsigned int)decoder->dictionary_size ||
( rep0 >= (unsigned int)decoder->pos && !decoder->partial_data_pos ) )
{ LZd_flush_data( decoder ); return 1; }
}
LZd_copy_block( decoder, rep0, len );
}
}
}
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