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Diffstat (limited to '')
| -rw-r--r-- | decoder.cc | 289 |
1 files changed, 0 insertions, 289 deletions
diff --git a/decoder.cc b/decoder.cc deleted file mode 100644 index 0d8d4d5..0000000 --- a/decoder.cc +++ /dev/null @@ -1,289 +0,0 @@ -/* Lzlib - A compression library for lzip files - Copyright (C) 2009, 2010, 2011 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 library. 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 <stdint.h> - -#include "lzlib.h" -#include "lzip.h" -#include "decoder.h" - - -namespace Lzlib { - -const CRC32 crc32; - -// Seeks a member header and updates `get'. -// Returns true if it finds a valid header. -bool Range_decoder::find_header() throw() - { - while( get != put ) - { - if( buffer[get] == magic_string[0] ) - { - int g = get; - File_header header; - for( int i = 0; i < File_header::size; ++i ) - { - if( g == put ) return false; // not enough data - header.data[i] = buffer[g]; - if( ++g >= buffer_size ) g = 0; - } - if( header.verify() ) return true; - } - if( ++get >= buffer_size ) get = 0; - } - return false; - } - - -// Returns true, fills `header', and updates `get' if `get' points to a -// valid header. -// Else returns false and leaves `get' unmodified. -bool Range_decoder::read_header( File_header & header ) throw() - { - int g = get; - for( int i = 0; i < File_header::size; ++i ) - { - if( g == put ) return false; // not enough data - header.data[i] = buffer[g]; - if( ++g >= buffer_size ) g = 0; - } - if( header.verify() ) - { - get = g; - member_pos = File_header::size; - reload_pending = true; - return true; - } - return false; - } - - -bool LZ_decoder::verify_trailer() - { - File_trailer trailer; - const int trailer_size = File_trailer::size( member_version ); - const long long member_size = range_decoder.member_position() + trailer_size; - bool error = false; - - for( int i = 0; i < trailer_size && !error; ++i ) - { - if( !range_decoder.finished() ) - trailer.data[i] = range_decoder.get_byte(); - else - { - error = true; - for( ; i < trailer_size; ++i ) trailer.data[i] = 0; - } - } - if( member_version == 0 ) trailer.member_size( member_size ); - if( !range_decoder.code_is_zero() ) error = true; - if( trailer.data_crc() != crc() ) error = true; - if( trailer.data_size() != data_position() ) error = true; - if( trailer.member_size() != member_size ) 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; - if( !range_decoder.try_reload() ) return 0; - if( verify_trailer_pending ) - { - if( range_decoder.available_bytes() < File_trailer::size( member_version ) && - !range_decoder.at_stream_end() ) - return 0; - verify_trailer_pending = false; - member_finished_ = true; - if( verify_trailer() ) return 0; else return 3; - } - while( true ) - { - if( range_decoder.finished() ) return 2; - if( !range_decoder.enough_available_bytes() || !enough_free_bytes() ) - return 0; - const int pos_state = data_position() & pos_state_mask; - if( range_decoder.decode_bit( bm_match[state()][pos_state] ) == 0 ) - { - const uint8_t prev_byte = get_prev_byte(); - if( state.is_char() ) - put_byte( literal_decoder.decode( range_decoder, prev_byte ) ); - else - put_byte( literal_decoder.decode_matched( range_decoder, prev_byte, - get_byte( rep0 ) ) ); - 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()] ) == 1 ) - { - 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; - } - else - { - if( range_decoder.decode_bit( bm_len[state()][pos_state] ) == 0 ) - { state.set_short_rep(); len = 1; } - } - if( len == 0 ) - { - state.set_rep(); - len = min_match_len + rep_match_len_decoder.decode( range_decoder, pos_state ); - } - } - else - { - const unsigned int rep0_saved = rep0; - len = min_match_len + len_decoder.decode( range_decoder, pos_state ); - 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 == 0xFFFFFFFFU ) // Marker found - { - rep0 = rep0_saved; - range_decoder.normalize(); - if( len == min_match_len ) // End Of Stream marker - { - if( range_decoder.available_bytes() < File_trailer::size( member_version ) && - !range_decoder.at_stream_end() ) - { verify_trailer_pending = true; return 0; } - member_finished_ = true; - if( verify_trailer() ) return 0; else return 3; - } - if( len == min_match_len + 1 ) // Sync Flush marker - { - if( range_decoder.try_reload( true ) ) continue; - else return 0; - } - return 4; - } - } - } - rep3 = rep2; rep2 = rep1; rep1 = rep0_saved; - state.set_match(); - if( rep0 >= (unsigned int)dictionary_size || - ( rep0 >= (unsigned int)put && !partial_data_pos ) ) - return 1; - } - copy_block( rep0, len ); - } - } - } - - -// Copies up to `out_size' bytes to `out_buffer' and updates `get'. -// Returns the number of bytes copied. -int Circular_buffer::read_data( uint8_t * const out_buffer, const int out_size ) throw() - { - if( out_size < 0 ) return 0; - int size = 0; - if( get > put ) - { - size = std::min( buffer_size - get, out_size ); - if( size > 0 ) - { - std::memcpy( 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::memcpy( out_buffer + size, buffer + get, size2 ); - get += size2; - size += size2; - } - } - return size; - } - - -// Copies up to `in_size' bytes from `in_buffer' and updates `put'. -// Returns the number of bytes copied. -int Circular_buffer::write_data( const uint8_t * const in_buffer, const int in_size ) throw() - { - if( in_size < 0 ) return 0; - int size = 0; - if( put >= get ) - { - size = std::min( buffer_size - put - (get == 0), in_size ); - if( size > 0 ) - { - std::memcpy( 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::memcpy( buffer + put, in_buffer + size, size2 ); - put += size2; - size += size2; - } - } - return size; - } - -} // end namespace Lzlib |