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-rw-r--r--decoder.h66
1 files changed, 29 insertions, 37 deletions
diff --git a/decoder.h b/decoder.h
index 36090c5..9fd1423 100644
--- a/decoder.h
+++ b/decoder.h
@@ -1,4 +1,4 @@
-/* Lzip - A data compressor based on the LZMA algorithm
+/* Lzip - Data compressor based on the LZMA algorithm
Copyright (C) 2008, 2009, 2010 Antonio Diaz Diaz.
This program is free software: you can redistribute it and/or modify
@@ -20,17 +20,17 @@ class Range_decoder
enum { buffer_size = 16384 };
long long partial_member_pos;
uint8_t * const buffer; // input buffer
- int pos;
+ int pos; // current pos in buffer
int stream_pos; // when reached, a new block must be read
uint32_t code;
uint32_t range;
- const int infd_; // input file descriptor
+ const int infd; // input file descriptor
bool at_stream_end;
bool read_block();
public:
- Range_decoder( const int infd )
+ Range_decoder( const int ifd )
:
partial_member_pos( 0 ),
buffer( new uint8_t[buffer_size] ),
@@ -38,13 +38,13 @@ public:
stream_pos( 0 ),
code( 0 ),
range( 0xFFFFFFFFU ),
- infd_( infd ),
+ infd( ifd ),
at_stream_end( false ) {}
~Range_decoder() { delete[] buffer; }
bool code_is_zero() const throw() { return ( code == 0 ); }
- bool finished() const throw() { return at_stream_end && pos >= stream_pos; }
+ bool finished() { return pos >= stream_pos && !read_block(); }
long long member_position() const throw()
{ return partial_member_pos + pos; }
void reset_member_position() throw()
@@ -52,11 +52,11 @@ public:
uint8_t get_byte()
{
- if( pos >= stream_pos && !read_block() ) return 0;
+ if( finished() ) return 0;
return buffer[pos++];
}
- void load() throw()
+ void load()
{
code = 0;
range = 0xFFFFFFFFU;
@@ -185,36 +185,32 @@ public:
uint8_t decode_matched( Range_decoder & range_decoder,
const uint8_t prev_byte, const uint8_t match_byte )
- { return range_decoder.decode_matched( bm_literal[lstate(prev_byte)], match_byte ); }
+ { return range_decoder.decode_matched( bm_literal[lstate(prev_byte)],
+ match_byte ); }
};
class LZ_decoder
{
long long partial_data_pos;
- const int member_version;
const int dictionary_size;
const int buffer_size;
- uint8_t * const buffer;
- int pos;
+ uint8_t * const buffer; // output buffer
+ int pos; // current pos in buffer
int stream_pos; // first byte not yet written to file
uint32_t crc_;
- const int outfd_; // output file descriptor
-
- Bit_model bm_match[State::states][pos_states];
- Bit_model bm_rep[State::states];
- Bit_model bm_rep0[State::states];
- Bit_model bm_rep1[State::states];
- Bit_model bm_rep2[State::states];
- Bit_model bm_len[State::states][pos_states];
- Bit_model bm_dis_slot[max_dis_states][1<<dis_slot_bits];
- Bit_model bm_dis[modeled_distances-end_dis_model];
- Bit_model bm_align[dis_align_size];
-
+ const int outfd; // output file descriptor
+ const int member_version;
Range_decoder & range_decoder;
- Len_decoder len_decoder;
- Len_decoder rep_match_len_decoder;
- Literal_decoder literal_decoder;
+
+ void flush_data();
+ bool verify_trailer( const Pretty_print & pp ) const;
+
+ uint8_t get_prev_byte() const throw()
+ {
+ const int i = ( ( pos > 0 ) ? pos : buffer_size ) - 1;
+ return buffer[i];
+ }
uint8_t get_byte( const int distance ) const throw()
{
@@ -238,7 +234,7 @@ class LZ_decoder
std::memcpy( buffer + pos, buffer + i, len );
pos += len;
}
- else for( ; len > 0 ; --len )
+ else for( ; len > 0; --len )
{
buffer[pos] = buffer[i];
if( ++pos >= buffer_size ) flush_data();
@@ -246,31 +242,27 @@ class LZ_decoder
}
}
- void flush_data();
- bool verify_trailer( const Pretty_print & pp ) const;
-
public:
- LZ_decoder( const File_header & header, Range_decoder & rdec, const int outfd )
+ LZ_decoder( const File_header & header, Range_decoder & rdec, const int ofd )
:
partial_data_pos( 0 ),
- member_version( header.version() ),
dictionary_size( header.dictionary_size() ),
buffer_size( std::max( 65536, dictionary_size ) ),
buffer( new uint8_t[buffer_size] ),
pos( 0 ),
stream_pos( 0 ),
crc_( 0xFFFFFFFFU ),
- outfd_( outfd ),
+ outfd( ofd ),
+ member_version( header.version() ),
range_decoder( rdec )
{ buffer[buffer_size-1] = 0; } // prev_byte of first_byte
~LZ_decoder() { delete[] buffer; }
uint32_t crc() const throw() { return crc_ ^ 0xFFFFFFFFU; }
- int decode_member( const Pretty_print & pp );
- long long member_position() const throw()
- { return range_decoder.member_position(); }
long long data_position() const throw()
{ return partial_data_pos + pos; }
+
+ int decode_member( const Pretty_print & pp );
};