summaryrefslogtreecommitdiffstats
path: root/decoder.cc
diff options
context:
space:
mode:
authorDaniel Baumann <mail@daniel-baumann.ch>2015-11-07 13:32:21 +0000
committerDaniel Baumann <mail@daniel-baumann.ch>2015-11-07 13:32:21 +0000
commita061471f450a2efc60371f90ac9483c8ed4375fd (patch)
tree640c3865c87f5e32bf0e98aac1edb0221c96c39c /decoder.cc
parentInitial commit. (diff)
downloadlzlib-a061471f450a2efc60371f90ac9483c8ed4375fd.tar.xz
lzlib-a061471f450a2efc60371f90ac9483c8ed4375fd.zip
Adding upstream version 0.3.upstream/0.3
Signed-off-by: Daniel Baumann <mail@daniel-baumann.ch>
Diffstat (limited to 'decoder.cc')
-rw-r--r--decoder.cc207
1 files changed, 207 insertions, 0 deletions
diff --git a/decoder.cc b/decoder.cc
new file mode 100644
index 0000000..aa394de
--- /dev/null
+++ b/decoder.cc
@@ -0,0 +1,207 @@
+/* Lzlib - A compression library for lzip files
+ Copyright (C) 2009 Antonio Diaz Diaz.
+
+ This library 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 library 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/>.
+
+ As a special exception, you may use this file as part of a free
+ software library without restriction. Specifically, if other files
+ instantiate templates or use macros or inline functions from this
+ file, or you compile this file and link it with other files to
+ produce an executable, this file does not by itself cause the
+ resulting executable to be covered by the GNU General Public
+ License. This exception does not however invalidate any other
+ reasons why the executable file might be covered by the GNU General
+ Public License.
+*/
+
+#define _FILE_OFFSET_BITS 64
+
+#include <algorithm>
+#include <cerrno>
+#include <cstdlib>
+#include <cstring>
+#include <string>
+#include <vector>
+#include <stdint.h>
+
+#include "lzlib.h"
+#include "lzip.h"
+#include "decoder.h"
+
+
+const CRC32 crc32;
+
+
+int Circular_buffer::read_data( uint8_t * const out_buffer, const int out_size ) throw()
+ {
+ int size = 0;
+ if( get > put )
+ {
+ size = std::min( buffer_size - get, out_size );
+ if( size > 0 )
+ {
+ std::memmove( out_buffer, buffer + get, size );
+ get += size;
+ if( get >= buffer_size ) get = 0;
+ }
+ }
+ if( get < put )
+ {
+ const int size2 = std::min( put - get, out_size - size );
+ if( size2 > 0 )
+ {
+ std::memmove( out_buffer + size, buffer + get, size2 );
+ get += size2;
+ size += size2;
+ }
+ }
+ return size;
+ }
+
+
+int Circular_buffer::write_data( uint8_t * const in_buffer, const int in_size ) throw()
+ {
+ int size = 0;
+ if( put >= get )
+ {
+ size = std::min( buffer_size - put - (get == 0), in_size );
+ if( size > 0 )
+ {
+ std::memmove( buffer + put, in_buffer, size );
+ put += size;
+ if( put >= buffer_size ) put = 0;
+ }
+ }
+ if( put < get )
+ {
+ const int size2 = std::min( get - put - 1, in_size - size );
+ if( size2 > 0 )
+ {
+ std::memmove( buffer + put, in_buffer + size, size2 );
+ put += size2;
+ size += size2;
+ }
+ }
+ return size;
+ }
+
+
+bool LZ_decoder::verify_trailer()
+ {
+ 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;
+ ((uint8_t *)&trailer)[i] = range_decoder.get_byte();
+ }
+ if( format_version == 0 ) trailer.member_size( member_position() );
+ if( trailer.data_crc() != crc() ) error = true;
+ if( trailer.data_size() != data_position() ) error = true;
+ if( trailer.member_size() != member_position() ) error = true;
+ return !error;
+ }
+
+
+ // Return value: 0 = OK, 1 = decoder error, 2 = unexpected EOF,
+ // 3 = trailer error, 4 = unknown marker found.
+int LZ_decoder::decode_member()
+ {
+ if( member_finished_ ) return 0;
+ while( true )
+ {
+ if( range_decoder.available_bytes() <= 0 ||
+ ( !range_decoder.at_stream_end() &&
+ range_decoder.available_bytes() < min_available_bytes ) )
+ return 0; // need more data
+ if( free_bytes() < max_match_len ) return 0;
+ if( range_decoder.finished() ) 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
+ {
+ member_finished_ = true;
+ if( verify_trailer() ) return 0; else return 3;
+ }
+ return 4;
+ }
+ }
+ }
+ }
+ if( !copy_block( rep0, len ) ) return 1;
+ prev_byte = get_byte( 0 );
+ }
+ }
+ }