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clzip/decoder.c
Daniel Baumann fe6e695444
Merging upstream version 1.15~rc1. 
Signed-off-by: Daniel Baumann <daniel@debian.org>
2025-02-17 20:54:18 +01:00

282 lines
9.3 KiB
C
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/* Clzip - LZMA lossless data compressor
Copyright (C) 2010-2024 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 <errno.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "lzip.h"
#include "decoder.h"
/* Return the number of bytes really read.
If (value returned < size) and (errno == 0), means EOF was reached.
*/
int readblock( const int fd, uint8_t * const buf, const int size )
{
int sz = 0;
errno = 0;
while( sz < size )
{
const int n = read( fd, buf + sz, size - sz );
if( n > 0 ) sz += n;
else if( n == 0 ) break; /* EOF */
else if( errno != EINTR ) break;
errno = 0;
}
return sz;
}
/* Return the number of bytes really written.
If (value returned < size), it is always an error.
*/
int writeblock( const int fd, const uint8_t * const buf, const int size )
{
int sz = 0;
errno = 0;
while( sz < size )
{
const int n = write( fd, buf + sz, size - sz );
if( n > 0 ) sz += n;
else if( n < 0 && errno != EINTR ) break;
errno = 0;
}
return sz;
}
bool Rd_read_block( 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;
show_dprogress( 0, 0, 0, 0 );
}
return rdec->pos < rdec->stream_pos;
}
void LZd_flush_data( LZ_decoder * const d )
{
if( d->pos > d->stream_pos )
{
const int size = d->pos - d->stream_pos;
CRC32_update_buf( &d->crc, d->buffer + d->stream_pos, size );
if( d->outfd >= 0 &&
writeblock( d->outfd, d->buffer + d->stream_pos, size ) != size )
{ show_error( write_error_msg, errno, false ); cleanup_and_fail( 1 ); }
if( d->pos >= d->dictionary_size )
{ d->partial_data_pos += d->pos; d->pos = 0; d->pos_wrapped = true; }
d->stream_pos = d->pos;
}
}
static bool LZd_check_trailer( LZ_decoder * const d, Pretty_print * const pp )
{
Lzip_trailer trailer;
int size = Rd_read_data( d->rdec, trailer, Lt_size );
bool error = false;
if( size < Lt_size )
{
error = true;
if( verbosity >= 0 )
{ Pp_show_msg( pp, 0 );
fprintf( stderr, "Trailer truncated at trailer position %d;"
" some checks may fail.\n", size ); }
while( size < Lt_size ) trailer[size++] = 0;
}
const unsigned td_crc = Lt_get_data_crc( trailer );
if( td_crc != LZd_crc( d ) )
{
error = true;
if( verbosity >= 0 )
{ Pp_show_msg( pp, 0 );
fprintf( stderr, "CRC mismatch; stored %08X, computed %08X\n",
td_crc, LZd_crc( d ) ); }
}
const unsigned long long data_size = LZd_data_position( d );
const unsigned long long td_size = Lt_get_data_size( trailer );
if( td_size != data_size )
{
error = true;
if( verbosity >= 0 )
{ Pp_show_msg( pp, 0 );
fprintf( stderr, "Data size mismatch; stored %llu (0x%llX), computed %llu (0x%llX)\n",
td_size, td_size, data_size, data_size ); }
}
const unsigned long long member_size = Rd_member_position( d->rdec );
const unsigned long long tm_size = Lt_get_member_size( trailer );
if( tm_size != member_size )
{
error = true;
if( verbosity >= 0 )
{ Pp_show_msg( pp, 0 );
fprintf( stderr, "Member size mismatch; stored %llu (0x%llX), computed %llu (0x%llX)\n",
tm_size, tm_size, member_size, member_size ); }
}
if( error ) return false;
if( verbosity >= 2 )
{
if( verbosity >= 4 ) show_header( d->dictionary_size );
if( data_size == 0 || member_size == 0 )
fputs( "no data compressed. ", stderr );
else
fprintf( stderr, "%6.3f:1, %5.2f%% ratio, %5.2f%% saved. ",
(double)data_size / member_size,
( 100.0 * member_size ) / data_size,
100.0 - ( ( 100.0 * member_size ) / data_size ) );
if( verbosity >= 4 ) fprintf( stderr, "CRC %08X, ", td_crc );
if( verbosity >= 3 )
fprintf( stderr, "%9llu out, %8llu in. ", data_size, member_size );
}
return true;
}
/* Return value: 0 = OK, 1 = decoder error, 2 = unexpected EOF,
3 = trailer error, 4 = unknown marker found,
5 = nonzero first LZMA byte found. */
int LZd_decode_member( LZ_decoder * const d, Pretty_print * const pp )
{
Range_decoder * const rdec = d->rdec;
Bit_model bm_literal[1<<literal_context_bits][0x300];
Bit_model bm_match[states][pos_states];
Bit_model bm_rep[states];
Bit_model bm_rep0[states];
Bit_model bm_rep1[states];
Bit_model bm_rep2[states];
Bit_model bm_len[states][pos_states];
Bit_model bm_dis_slot[len_states][1<<dis_slot_bits];
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;
unsigned rep0 = 0; /* rep[0-3] latest four distances */
unsigned rep1 = 0; /* used for efficient coding of */
unsigned rep2 = 0; /* repeated distances */
unsigned rep3 = 0;
State state = 0;
Bm_array_init( bm_literal[0], (1 << literal_context_bits) * 0x300 );
Bm_array_init( bm_match[0], states * pos_states );
Bm_array_init( bm_rep, states );
Bm_array_init( bm_rep0, states );
Bm_array_init( bm_rep1, states );
Bm_array_init( bm_rep2, states );
Bm_array_init( bm_len[0], states * pos_states );
Bm_array_init( bm_dis_slot[0], len_states * (1 << dis_slot_bits) );
Bm_array_init( bm_dis, modeled_distances - end_dis_model + 1 );
Bm_array_init( bm_align, dis_align_size );
Lm_init( &match_len_model );
Lm_init( &rep_len_model );
if( !Rd_load( rdec ) ) return 5;
while( !Rd_finished( rdec ) )
{
const int pos_state = LZd_data_position( d ) & pos_state_mask;
if( Rd_decode_bit( rdec, &bm_match[state][pos_state] ) == 0 ) /* 1st bit */
{
/* literal byte */
Bit_model * const bm = bm_literal[get_lit_state(LZd_peek_prev( d ))];
if( ( state = St_set_char( state ) ) < 4 )
LZd_put_byte( d, Rd_decode_tree8( rdec, bm ) );
else
LZd_put_byte( d, Rd_decode_matched( rdec, bm, LZd_peek( d, rep0 ) ) );
continue;
}
/* match or repeated match */
int len;
if( Rd_decode_bit( rdec, &bm_rep[state] ) != 0 ) /* 2nd bit */
{
if( Rd_decode_bit( rdec, &bm_rep0[state] ) == 0 ) /* 3rd bit */
{
if( Rd_decode_bit( rdec, &bm_len[state][pos_state] ) == 0 ) /* 4th bit */
{ state = St_set_short_rep( state );
LZd_put_byte( d, LZd_peek( d, rep0 ) ); continue; }
}
else
{
unsigned distance;
if( Rd_decode_bit( rdec, &bm_rep1[state] ) == 0 ) /* 4th bit */
distance = rep1;
else
{
if( Rd_decode_bit( rdec, &bm_rep2[state] ) == 0 ) /* 5th bit */
distance = rep2;
else
{ distance = rep3; rep3 = rep2; }
rep2 = rep1;
}
rep1 = rep0;
rep0 = distance;
}
state = St_set_rep( state );
len = Rd_decode_len( rdec, &rep_len_model, pos_state );
}
else /* match */
{
rep3 = rep2; rep2 = rep1; rep1 = rep0;
len = Rd_decode_len( rdec, &match_len_model, pos_state );
rep0 = Rd_decode_tree6( rdec, bm_dis_slot[get_len_state(len)] );
if( rep0 >= start_dis_model )
{
const unsigned dis_slot = rep0;
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( rdec, bm_dis + ( rep0 - dis_slot ),
direct_bits );
else
{
rep0 += Rd_decode( rdec, direct_bits - dis_align_bits ) << dis_align_bits;
rep0 += Rd_decode_tree_reversed4( rdec, bm_align );
if( rep0 == 0xFFFFFFFFU ) /* marker found */
{
Rd_normalize( rdec );
LZd_flush_data( d );
if( len == min_match_len ) /* End Of Stream marker */
{ if( LZd_check_trailer( d, pp ) ) return 0; else return 3; }
if( verbosity >= 0 ) { Pp_show_msg( pp, 0 );
fprintf( stderr, "Unsupported marker code '%d'\n", len ); }
return 4;
}
}
}
state = St_set_match( state );
if( rep0 >= d->dictionary_size || ( rep0 >= d->pos && !d->pos_wrapped ) )
{ LZd_flush_data( d ); return 1; }
}
LZd_copy_block( d, rep0, len );
}
LZd_flush_data( d );
return 2;
}
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