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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-14 12:54:40 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-14 12:54:40 +0000
commit47d9004eff8861813477ed571350f7cd83ea4fd4 (patch)
treef909edd49006917e1d3cdae838ca56f5fa7fc9ff /decoder.c
parentInitial commit. (diff)
downloadlunzip-upstream/1.14.tar.xz
lunzip-upstream/1.14.zip
Adding upstream version 1.14.upstream/1.14upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'decoder.c')
-rw-r--r--decoder.c309
1 files changed, 309 insertions, 0 deletions
diff --git a/decoder.c b/decoder.c
new file mode 100644
index 0000000..5f1dc5e
--- /dev/null
+++ b/decoder.c
@@ -0,0 +1,309 @@
+/* Lunzip - Decompressor for the lzip format
+ 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"
+
+
+CRC32 crc32;
+
+
+/* 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.
+*/
+static 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;
+ }
+
+
+unsigned seek_read_back( const int fd, uint8_t * const buf, const int size,
+ const int offset )
+ {
+ if( lseek( fd, -offset, SEEK_END ) >= 0 )
+ return readblock( fd, buf, size );
+ return 0;
+ }
+
+
+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;
+ show_dprogress( 0, 0, 0, 0 );
+ }
+ return rdec->pos < rdec->stream_pos;
+ }
+
+
+void LZd_flush_data( struct 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", errno, false ); cleanup_and_fail( 1 ); }
+ if( d->pos >= d->buffer_size )
+ { d->partial_data_pos += d->pos; d->pos = 0;
+ if( d->partial_data_pos >= d->dictionary_size ) d->pos_wrapped = true; }
+ d->stream_pos = d->pos;
+ }
+ }
+
+
+static int LZd_check_trailer( struct LZ_decoder * const d,
+ struct Pretty_print * const pp,
+ const bool ignore_empty )
+ {
+ 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 3;
+ if( !ignore_empty && data_size == 0 ) return 5;
+ 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 0;
+ }
+
+
+/* Return value: 0 = OK, 1 = decoder error, 2 = unexpected EOF,
+ 3 = trailer error, 4 = unknown marker found,
+ 5 = empty member found, 6 = marked member found. */
+int LZd_decode_member( struct LZ_decoder * const d,
+ const struct Cl_options * const cl_opts,
+ struct Pretty_print * const pp )
+ {
+ struct 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];
+ struct Len_model match_len_model;
+ struct 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;
+ const bool full_buffer = d->buffer_size >= d->dictionary_size;
+
+ 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, cl_opts->ignore_marking ) ) return 6;
+ 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 */
+ {
+ len = Rd_decode_len( rdec, &match_len_model, pos_state );
+ unsigned distance = Rd_decode_tree6( rdec, 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 += Rd_decode_tree_reversed( rdec,
+ bm_dis + ( distance - dis_slot ), direct_bits );
+ else
+ {
+ distance +=
+ Rd_decode( rdec, direct_bits - dis_align_bits ) << dis_align_bits;
+ distance += Rd_decode_tree_reversed4( rdec, bm_align );
+ if( distance == 0xFFFFFFFFU ) /* marker found */
+ {
+ Rd_normalize( rdec );
+ LZd_flush_data( d );
+ if( len == min_match_len ) /* End Of Stream marker */
+ return LZd_check_trailer( d, pp, cl_opts->ignore_empty );
+ if( len == min_match_len + 1 ) /* Sync Flush marker */
+ { Rd_load( rdec, true ); continue; }
+ if( verbosity >= 0 )
+ {
+ Pp_show_msg( pp, 0 );
+ fprintf( stderr, "Unsupported marker code '%d'\n", len );
+ }
+ return 4;
+ }
+ }
+ }
+ rep3 = rep2; rep2 = rep1; rep1 = rep0; rep0 = distance;
+ state = St_set_match( state );
+ if( rep0 >= d->dictionary_size ||
+ ( !d->pos_wrapped && rep0 >= LZd_data_position( d ) ) )
+ { LZd_flush_data( d ); return 1; }
+ }
+ if( full_buffer || rep0 < d->buffer_size ) LZd_copy_block( d, rep0, len );
+ else LZd_copy_block2( d, rep0, len );
+ }
+ LZd_flush_data( d );
+ return 2;
+ }