diff options
Diffstat (limited to 'decoder.cc')
| -rw-r--r-- | decoder.cc | 58 |
1 files changed, 51 insertions, 7 deletions
@@ -1,5 +1,5 @@ /* Lzlib - A compression library for lzip files - Copyright (C) 2009 Antonio Diaz Diaz. + Copyright (C) 2009, 2010 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 @@ -12,7 +12,7 @@ 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/>. + 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 @@ -31,8 +31,6 @@ #include <cerrno> #include <cstdlib> #include <cstring> -#include <string> -#include <vector> #include <stdint.h> #include "lzlib.h" @@ -42,7 +40,8 @@ const CRC32 crc32; - +// 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() { int size = 0; @@ -70,6 +69,8 @@ int Circular_buffer::read_data( uint8_t * const out_buffer, const int out_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() { int size = 0; @@ -97,6 +98,47 @@ int Circular_buffer::write_data( const uint8_t * const in_buffer, const int in_s } +// Seeks a member header and updates `get'. +// Returns true if it finds a valid header. +bool Input_buffer::find_header() throw() + { + while( get != put ) + { + if( buffer[get] == magic_string[0] ) + { + int g = get; + File_header header; + for( unsigned int i = 0; i < sizeof header; ++i ) + { + if( g == put ) return false; // not enough data + ((uint8_t *)&header)[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 Input_buffer::read_header( File_header & header ) throw() + { + int g = get; + for( unsigned int i = 0; i < sizeof header; ++i ) + { + if( g == put ) return false; // not enough data + ((uint8_t *)&header)[i] = buffer[g]; + if( ++g >= buffer_size ) g = 0; + } + if( header.verify() ) { get = g; return true; } + return false; + } + + bool LZ_decoder::verify_trailer() { bool error = false; @@ -125,7 +167,8 @@ int LZ_decoder::decode_member() if( !range_decoder.try_reload() ) return 0; if( verify_trailer_pending ) { - if( range_decoder.available_bytes() < File_trailer::size( format_version ) ) + if( range_decoder.available_bytes() < File_trailer::size( format_version ) && + !range_decoder.at_stream_end() ) return 0; verify_trailer_pending = false; member_finished_ = true; @@ -201,7 +244,8 @@ int LZ_decoder::decode_member() range_decoder.normalize(); if( len == min_match_len ) // End Of Stream marker { - if( range_decoder.available_bytes() < File_trailer::size( format_version ) ) + if( range_decoder.available_bytes() < File_trailer::size( format_version ) && + !range_decoder.at_stream_end() ) { verify_trailer_pending = true; return 0; } member_finished_ = true; if( verify_trailer() ) return 0; else return 3; |