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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-14 12:53:35 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-14 12:53:35 +0000
commit762a5e638314efa0f7a070e8568bfaf35bc87315 (patch)
treec2f4352237b3101986b8085626f0d77f6cfa18c7 /decoder.cc
parentInitial commit. (diff)
downloadlzip-762a5e638314efa0f7a070e8568bfaf35bc87315.tar.xz
lzip-762a5e638314efa0f7a070e8568bfaf35bc87315.zip
Adding upstream version 1.24.1.upstream/1.24.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'decoder.cc')
-rw-r--r--decoder.cc276
1 files changed, 276 insertions, 0 deletions
diff --git a/decoder.cc b/decoder.cc
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--- /dev/null
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+/* Lzip - LZMA lossless data compressor
+ Copyright (C) 2008-2024 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 <algorithm>
+#include <cerrno>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <string>
+#include <vector>
+#include <stdint.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 Range_decoder::read_block()
+ {
+ if( !at_stream_end )
+ {
+ stream_pos = readblock( infd, buffer, buffer_size );
+ if( stream_pos != buffer_size && errno ) throw Error( "Read error" );
+ at_stream_end = ( stream_pos < buffer_size );
+ partial_member_pos += pos;
+ pos = 0;
+ show_dprogress();
+ }
+ return pos < stream_pos;
+ }
+
+
+void LZ_decoder::flush_data()
+ {
+ if( pos > stream_pos )
+ {
+ const int size = pos - stream_pos;
+ crc32.update_buf( crc_, buffer + stream_pos, size );
+ if( outfd >= 0 && writeblock( outfd, buffer + stream_pos, size ) != size )
+ throw Error( "Write error" );
+ if( pos >= dictionary_size )
+ { partial_data_pos += pos; pos = 0; pos_wrapped = true; }
+ stream_pos = pos;
+ }
+ }
+
+
+int LZ_decoder::check_trailer( const Pretty_print & pp,
+ const bool ignore_empty ) const
+ {
+ Lzip_trailer trailer;
+ int size = rdec.read_data( trailer.data, trailer.size );
+ bool error = false;
+
+ if( size < trailer.size )
+ {
+ error = true;
+ if( verbosity >= 0 )
+ { pp();
+ std::fprintf( stderr, "Trailer truncated at trailer position %d;"
+ " some checks may fail.\n", size ); }
+ while( size < trailer.size ) trailer.data[size++] = 0;
+ }
+
+ const unsigned td_crc = trailer.data_crc();
+ if( td_crc != crc() )
+ {
+ error = true;
+ if( verbosity >= 0 )
+ { pp();
+ std::fprintf( stderr, "CRC mismatch; stored %08X, computed %08X\n",
+ td_crc, crc() ); }
+ }
+ const unsigned long long data_size = data_position();
+ const unsigned long long td_size = trailer.data_size();
+ if( td_size != data_size )
+ {
+ error = true;
+ if( verbosity >= 0 )
+ { pp();
+ std::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 = rdec.member_position();
+ const unsigned long long tm_size = trailer.member_size();
+ if( tm_size != member_size )
+ {
+ error = true;
+ if( verbosity >= 0 )
+ { pp();
+ std::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( dictionary_size );
+ if( data_size == 0 || member_size == 0 )
+ std::fputs( "no data compressed. ", stderr );
+ else
+ std::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 ) std::fprintf( stderr, "CRC %08X, ", td_crc );
+ if( verbosity >= 3 )
+ std::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 LZ_decoder::decode_member( const Cl_options & cl_opts,
+ const Pretty_print & pp )
+ {
+ Bit_model bm_literal[1<<literal_context_bits][0x300];
+ Bit_model bm_match[State::states][pos_states];
+ Bit_model bm_rep[State::states];
+ Bit_model bm_rep0[State::states];
+ Bit_model bm_rep1[State::states];
+ 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+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;
+
+ if( !rdec.load( cl_opts.ignore_marking ) ) return 6;
+ while( !rdec.finished() )
+ {
+ 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;
+ }
+ // 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_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
+ {
+ if( rdec.decode_bit( bm_rep2[state()] ) == 0 ) // 5th bit
+ distance = rep2;
+ else
+ { distance = rep3; rep3 = rep2; }
+ rep2 = rep1;
+ }
+ rep1 = rep0;
+ rep0 = distance;
+ }
+ state.set_rep();
+ len = rdec.decode_len( rep_len_model, pos_state );
+ }
+ else // 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
+ {
+ 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
+ return check_trailer( pp, cl_opts.ignore_empty );
+ 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;
+ }
+ }
+ }
+ 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;
+ }