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-rw-r--r--decoder.cc58
1 files changed, 51 insertions, 7 deletions
diff --git a/decoder.cc b/decoder.cc
index 5f44309..2577230 100644
--- a/decoder.cc
+++ b/decoder.cc
@@ -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;