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-rw-r--r--decoder.cc162
1 files changed, 85 insertions, 77 deletions
diff --git a/decoder.cc b/decoder.cc
index 429d33e..a260571 100644
--- a/decoder.cc
+++ b/decoder.cc
@@ -38,71 +38,11 @@
#include "decoder.h"
-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()
- {
- 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;
- }
-
+const CRC32 Lzlib_namespace::crc32;
// Seeks a member header and updates `get'.
// Returns true if it finds a valid header.
-bool Input_buffer::find_header() throw()
+bool Range_decoder::find_header() throw()
{
while( get != put )
{
@@ -110,10 +50,10 @@ bool Input_buffer::find_header() throw()
{
int g = get;
File_header header;
- for( unsigned int i = 0; i < sizeof header; ++i )
+ for( int i = 0; i < File_header::size; ++i )
{
if( g == put ) return false; // not enough data
- ((uint8_t *)&header)[i] = buffer[g];
+ header.data[i] = buffer[g];
if( ++g >= buffer_size ) g = 0;
}
if( header.verify() ) return true;
@@ -127,36 +67,44 @@ bool Input_buffer::find_header() throw()
// 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()
+bool Range_decoder::read_header( File_header & header ) throw()
{
int g = get;
- for( unsigned int i = 0; i < sizeof header; ++i )
+ for( int i = 0; i < File_header::size; ++i )
{
if( g == put ) return false; // not enough data
- ((uint8_t *)&header)[i] = buffer[g];
+ header.data[i] = buffer[g];
if( ++g >= buffer_size ) g = 0;
}
- if( header.verify() ) { get = g; return true; }
+ if( header.verify() )
+ {
+ get = g;
+ member_pos = File_header::size;
+ reload_pending = true;
+ return true;
+ }
return false;
}
bool LZ_decoder::verify_trailer()
{
- bool error = false;
File_trailer trailer;
- const int trailer_size = trailer.size( format_version );
+ 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() )
- ((uint8_t *)&trailer)[i] = range_decoder.get_byte();
- else error = true;
+ trailer.data[i] = range_decoder.get_byte();
+ else { error = true; for( ; i < trailer_size; ++i ) trailer.data[i] = 0; }
}
- if( format_version == 0 ) trailer.member_size( member_position() );
+ 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_position() ) error = true;
+ if( trailer.member_size() != member_size ) error = true;
return !error;
}
@@ -169,7 +117,7 @@ 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( member_version ) &&
!range_decoder.at_stream_end() )
return 0;
verify_trailer_pending = false;
@@ -240,13 +188,13 @@ int LZ_decoder::decode_member()
{
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( 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( format_version ) &&
+ if( range_decoder.available_bytes() < File_trailer::size( member_version ) &&
!range_decoder.at_stream_end() )
{ verify_trailer_pending = true; return 0; }
member_finished_ = true;
@@ -269,3 +217,63 @@ int LZ_decoder::decode_member()
}
}
}
+
+
+// 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;
+ }