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authorDaniel Baumann <mail@daniel-baumann.ch>2015-11-07 07:22:08 +0000
committerDaniel Baumann <mail@daniel-baumann.ch>2015-11-07 07:22:08 +0000
commitce537b6151b2105c25d979bf40f445051754b798 (patch)
treebb514ec997e349d51d1565d98e79297407c1339a /decoder.cc
parentInitial commit. (diff)
downloadlzip-ce537b6151b2105c25d979bf40f445051754b798.tar.xz
lzip-ce537b6151b2105c25d979bf40f445051754b798.zip
Adding upstream version 1.6~pre1.upstream/1.6_pre1
Signed-off-by: Daniel Baumann <mail@daniel-baumann.ch>
Diffstat (limited to 'decoder.cc')
-rw-r--r--decoder.cc218
1 files changed, 218 insertions, 0 deletions
diff --git a/decoder.cc b/decoder.cc
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+/* Lzip - A data compressor based on the LZMA algorithm
+ Copyright (C) 2008, 2009 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 <cerrno>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <string>
+#include <vector>
+#include <stdint.h>
+
+#include "lzip.h"
+#include "decoder.h"
+
+
+const CRC32 crc32;
+
+
+bool Input_buffer::read_block()
+ {
+ if( at_stream_end ) return false;
+ stream_pos = readblock( ides_, (char *)buffer, buffer_size );
+ if( stream_pos != buffer_size && errno ) throw Error( "read error" );
+ pos = 0;
+ at_stream_end = ( stream_pos < buffer_size );
+ return !finished();
+ }
+
+
+void LZ_decoder::flush_data()
+ {
+ if( !member_finished )
+ {
+ if( odes_ >= 0 )
+ {
+ const int wr = writeblock( odes_, (char *)buffer, pos );
+ if( wr != pos ) throw Error( "write error" );
+ }
+ if( pos >= buffer_size ) { partial_data_pos += pos; pos = 0; }
+ else member_finished = true;
+ }
+ }
+
+
+bool LZ_decoder::verify_trailer( const Pretty_print & pp ) const
+ {
+ bool error = false;
+ File_trailer trailer;
+ const int trailer_size = trailer.size( format_version );
+ for( int i = 0; i < trailer_size && !error; ++i )
+ {
+ if( range_decoder.finished() )
+ {
+ error = true;
+ if( verbosity >= 0 )
+ {
+ pp();
+ std::fprintf( stderr, "trailer truncated at trailer position %d;"
+ " some checks may fail.\n", i );
+ }
+ }
+ ((uint8_t *)&trailer)[i] = range_decoder.read_byte();
+ }
+ if( format_version == 0 ) trailer.member_size( member_position() );
+ if( trailer.data_crc() != crc() )
+ {
+ error = true;
+ if( verbosity >= 0 )
+ {
+ pp();
+ std::fprintf( stderr, "crc mismatch; trailer says %08X, data crc is %08X.\n",
+ trailer.data_crc(), crc() );
+ }
+ }
+ if( trailer.data_size() != data_position() )
+ {
+ error = true;
+ if( verbosity >= 0 )
+ {
+ if( trailer.data_size() >= 0 )
+ { pp();
+ std::fprintf( stderr, "data size mismatch; trailer says %lld, data size is %lld.\n",
+ trailer.data_size(), data_position() ); }
+ else pp( "member trailer is corrupt" );
+ }
+ }
+ if( trailer.member_size() != member_position() )
+ {
+ error = true;
+ if( verbosity >= 0 )
+ {
+ if( trailer.member_size() >= 0 )
+ { pp();
+ std::fprintf( stderr, "member size mismatch; trailer says %lld, member size is %lld.\n",
+ trailer.member_size(), member_position() ); }
+ else pp( "member trailer is corrupt" );
+ }
+ }
+ if( !error && verbosity >= 3 )
+ std::fprintf( stderr, "data crc %08X, data size %8lld, member size %8lld. ",
+ trailer.data_crc(), trailer.data_size(), trailer.member_size() );
+ return !error;
+ }
+
+
+ // Return value: 0 = OK, 1 = decoder error, 2 = unexpected EOF,
+ // 3 = trailer error, 4 = unknown marker found.
+int LZ_decoder::decode_member( const Pretty_print & pp )
+ {
+ unsigned int rep0 = 0;
+ unsigned int rep1 = 0;
+ unsigned int rep2 = 0;
+ unsigned int rep3 = 0;
+ State state;
+ uint8_t prev_byte = 0;
+
+ while( true )
+ {
+ if( range_decoder.finished() ) { flush_data(); return 2; }
+ const int pos_state = data_position() & pos_state_mask;
+ if( range_decoder.decode_bit( bm_match[state()][pos_state] ) == 0 )
+ {
+ if( state.is_char() )
+ prev_byte = literal_decoder.decode( range_decoder, prev_byte );
+ else
+ prev_byte = literal_decoder.decode_matched( range_decoder, prev_byte,
+ get_byte( rep0 ) );
+ put_byte( prev_byte );
+ state.set_char();
+ }
+ else
+ {
+ int len;
+ if( range_decoder.decode_bit( bm_rep[state()] ) == 1 )
+ {
+ len = 0;
+ if( range_decoder.decode_bit( bm_rep0[state()] ) == 0 )
+ {
+ if( range_decoder.decode_bit( bm_len[state()][pos_state] ) == 0 )
+ { len = 1; state.set_short_rep(); }
+ }
+ else
+ {
+ unsigned int distance;
+ if( range_decoder.decode_bit( bm_rep1[state()] ) == 0 )
+ distance = rep1;
+ else
+ {
+ if( range_decoder.decode_bit( bm_rep2[state()] ) == 0 )
+ distance = rep2;
+ else { distance = rep3; rep3 = rep2; }
+ rep2 = rep1;
+ }
+ rep1 = rep0;
+ rep0 = distance;
+ }
+ if( len == 0 )
+ {
+ len = min_match_len + rep_match_len_decoder.decode( range_decoder, pos_state );
+ state.set_rep();
+ }
+ }
+ else
+ {
+ rep3 = rep2; rep2 = rep1; rep1 = rep0;
+ len = min_match_len + len_decoder.decode( range_decoder, pos_state );
+ state.set_match();
+ const int dis_slot = range_decoder.decode_tree( 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 += range_decoder.decode_tree_reversed( bm_dis + rep0 - dis_slot, direct_bits );
+ else
+ {
+ rep0 += range_decoder.decode( direct_bits - dis_align_bits ) << dis_align_bits;
+ rep0 += range_decoder.decode_tree_reversed( bm_align, dis_align_bits );
+ if( rep0 == 0xFFFFFFFF ) // Marker found
+ {
+ if( len == min_match_len ) // End Of Stream marker
+ {
+ flush_data();
+ if( verify_trailer( pp ) ) return 0; else return 3;
+ }
+ if( verbosity >= 0 )
+ {
+ pp();
+ std::fprintf( stderr, "unsupported marker code `%d'.\n", len );
+ }
+ flush_data();
+ return 4;
+ }
+ }
+ }
+ }
+ if( !copy_block( rep0, len ) ) { flush_data(); return 1; }
+ prev_byte = get_byte( 0 );
+ }
+ }
+ }