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-rw-r--r--decoder.h191
1 files changed, 84 insertions, 107 deletions
diff --git a/decoder.h b/decoder.h
index 7df68b9..1bb773c 100644
--- a/decoder.h
+++ b/decoder.h
@@ -15,182 +15,159 @@
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-enum { Ib_buffer_size = 65536 };
+enum { Rd_buffer_size = 16384 };
-struct Input_buffer
+struct Range_decoder
{
- uint8_t * buffer;
+ long long partial_member_pos;
+ uint8_t * buffer; // input buffer
int pos;
int stream_pos; // when reached, a new block must be read
+ uint32_t code;
+ uint32_t range;
int infd_; // input file descriptor
bool at_stream_end;
};
-bool Ib_read_block( struct Input_buffer * const ibuf );
+bool Rd_read_block( struct Range_decoder * const rdec );
-static inline void Ib_init( struct Input_buffer * const ibuf, const int infd )
+static inline void Rd_init( struct Range_decoder * const rdec, const int infd )
{
- ibuf->buffer = (uint8_t *)malloc( Ib_buffer_size );
- if( !ibuf->buffer )
+ rdec->partial_member_pos = 0;
+ rdec->buffer = (uint8_t *)malloc( Rd_buffer_size );
+ if( !rdec->buffer )
{
show_error( "not enough memory. Find a machine with more memory", 0, false );
cleanup_and_fail( 1 );
}
- ibuf->pos = 0;
- ibuf->stream_pos = 0;
- ibuf->infd_ = infd;
- ibuf->at_stream_end = false;
+ rdec->pos = 0;
+ rdec->stream_pos = 0;
+ rdec->code = 0;
+ rdec->range = 0xFFFFFFFF;
+ rdec->infd_ = infd;
+ rdec->at_stream_end = false;
}
-static inline void Ib_free( struct Input_buffer * const ibuf )
- { free( ibuf->buffer ); ibuf->buffer = 0; }
+static inline void Rd_free( struct Range_decoder * const rdec )
+ { free( rdec->buffer ); rdec->buffer = 0; }
-static inline bool Ib_finished( struct Input_buffer * const ibuf )
- { return ibuf->at_stream_end && ibuf->pos >= ibuf->stream_pos; }
+static inline bool Rd_code_is_zero( struct Range_decoder * const rdec )
+ { return ( rdec->code == 0 ); }
-static inline uint8_t Ib_get_byte( struct Input_buffer * const ibuf )
- {
- if( ibuf->pos >= ibuf->stream_pos && !Ib_read_block( ibuf ) )
- return 0;
- return ibuf->buffer[ibuf->pos++];
- }
+static inline bool Rd_finished( struct Range_decoder * const rdec )
+ { return rdec->at_stream_end && rdec->pos >= rdec->stream_pos; }
+static inline long long Rd_member_position( struct Range_decoder * const rdec )
+ { return rdec->partial_member_pos + rdec->pos; }
-struct Range_decoder
- {
- long long member_pos;
- uint32_t code;
- uint32_t range;
- struct Input_buffer * ibuf;
- };
+static inline void Rd_reset_member_position( struct Range_decoder * const rdec )
+ { rdec->partial_member_pos = -rdec->pos; }
-static inline uint8_t Rd_get_byte( struct Range_decoder * const range_decoder )
+static inline uint8_t Rd_get_byte( struct Range_decoder * const rdec )
{
- ++range_decoder->member_pos;
- return Ib_get_byte( range_decoder->ibuf );
+ if( rdec->pos >= rdec->stream_pos && !Rd_read_block( rdec ) ) return 0;
+ return rdec->buffer[rdec->pos++];
}
-static inline void Rd_init( struct Range_decoder * const range_decoder,
- struct Input_buffer * const buf )
+static inline void Rd_load( struct Range_decoder * const rdec )
{
- range_decoder->member_pos = sizeof (File_header);
- range_decoder->code = 0;
- range_decoder->range = 0xFFFFFFFF;
- range_decoder->ibuf = buf;
+ rdec->code = 0;
+ rdec->range = 0xFFFFFFFFU;
for( int i = 0; i < 5; ++i )
- range_decoder->code = (range_decoder->code << 8) |
- Rd_get_byte( range_decoder );
+ rdec->code = (rdec->code << 8) | Rd_get_byte( rdec );
}
-static inline bool Rd_code_is_zero( struct Range_decoder * const range_decoder )
- { return ( range_decoder->code == 0 ); }
-static inline bool Rd_finished( struct Range_decoder * const range_decoder )
- { return Ib_finished( range_decoder->ibuf ); }
-static inline long long Rd_member_position( struct Range_decoder * const range_decoder )
- { return range_decoder->member_pos; }
-
-static inline void Rd_reload( struct Range_decoder * const range_decoder )
+static inline void Rd_normalize( struct Range_decoder * const rdec )
{
- range_decoder->code = 0;
- range_decoder->range = 0xFFFFFFFF;
- for( int i = 0; i < 5; ++i )
- range_decoder->code = (range_decoder->code << 8) |
- Rd_get_byte( range_decoder );
- }
-
-static inline void Rd_normalize( struct Range_decoder * const range_decoder )
- {
- if( range_decoder->range <= 0x00FFFFFF )
+ if( rdec->range <= 0x00FFFFFFU )
{
- range_decoder->range <<= 8;
- range_decoder->code = (range_decoder->code << 8) |
- Rd_get_byte( range_decoder );
+ rdec->range <<= 8;
+ rdec->code = (rdec->code << 8) | Rd_get_byte( rdec );
}
}
-static inline int Rd_decode( struct Range_decoder * const range_decoder,
+static inline int Rd_decode( struct Range_decoder * const rdec,
const int num_bits )
{
int symbol = 0;
for( int i = num_bits; i > 0; --i )
{
symbol <<= 1;
- if( range_decoder->range <= 0x00FFFFFF )
+ if( rdec->range <= 0x00FFFFFFU )
{
- range_decoder->range <<= 7;
- range_decoder->code = (range_decoder->code << 8) |
- Rd_get_byte( range_decoder );
- if( range_decoder->code >= range_decoder->range )
- { range_decoder->code -= range_decoder->range; symbol |= 1; }
+ rdec->range <<= 7;
+ rdec->code = (rdec->code << 8) | Rd_get_byte( rdec );
+ if( rdec->code >= rdec->range )
+ { rdec->code -= rdec->range; symbol |= 1; }
}
else
{
- range_decoder->range >>= 1;
- if( range_decoder->code >= range_decoder->range )
- { range_decoder->code -= range_decoder->range; symbol |= 1; }
+ rdec->range >>= 1;
+ if( rdec->code >= rdec->range )
+ { rdec->code -= rdec->range; symbol |= 1; }
}
}
return symbol;
}
-static inline int Rd_decode_bit( struct Range_decoder * const range_decoder,
+static inline int Rd_decode_bit( struct Range_decoder * const rdec,
Bit_model * const probability )
{
- Rd_normalize( range_decoder );
- const uint32_t bound = ( range_decoder->range >> bit_model_total_bits ) *
+ Rd_normalize( rdec );
+ const uint32_t bound = ( rdec->range >> bit_model_total_bits ) *
*probability;
- if( range_decoder->code < bound )
+ if( rdec->code < bound )
{
- range_decoder->range = bound;
+ rdec->range = bound;
*probability += (bit_model_total - *probability) >> bit_model_move_bits;
return 0;
}
else
{
- range_decoder->range -= bound;
- range_decoder->code -= bound;
+ rdec->range -= bound;
+ rdec->code -= bound;
*probability -= *probability >> bit_model_move_bits;
return 1;
}
}
-static inline int Rd_decode_tree( struct Range_decoder * const range_decoder,
+static inline int Rd_decode_tree( struct Range_decoder * const rdec,
Bit_model bm[], const int num_bits )
{
int model = 1;
for( int i = num_bits; i > 0; --i )
- model = ( model << 1 ) | Rd_decode_bit( range_decoder, &bm[model] );
+ model = ( model << 1 ) | Rd_decode_bit( rdec, &bm[model] );
return model - (1 << num_bits);
}
-static inline int Rd_decode_tree_reversed( struct Range_decoder * const range_decoder,
+static inline int Rd_decode_tree_reversed( struct Range_decoder * const rdec,
Bit_model bm[], const int num_bits )
{
int model = 1;
int symbol = 0;
for( int i = 0; i < num_bits; ++i )
{
- const int bit = Rd_decode_bit( range_decoder, &bm[model] );
+ const int bit = Rd_decode_bit( rdec, &bm[model] );
model <<= 1;
if( bit ) { model |= 1; symbol |= (1 << i); }
}
return symbol;
}
-static inline int Rd_decode_matched( struct Range_decoder * const range_decoder,
+static inline int Rd_decode_matched( struct Range_decoder * const rdec,
Bit_model bm[], const int match_byte )
{
- Bit_model *bm1 = bm + 0x100;
+ Bit_model * const bm1 = bm + 0x100;
int symbol = 1;
- for( int i = 1; i <= 8; ++i )
+ for( int i = 7; i >= 0; --i )
{
- const int match_bit = ( match_byte << i ) & 0x100;
- const int bit = Rd_decode_bit( range_decoder, &bm1[match_bit+symbol] );
+ const int match_bit = ( match_byte >> i ) & 1;
+ const int bit = Rd_decode_bit( rdec, &bm1[(match_bit<<8)+symbol] );
symbol = ( symbol << 1 ) | bit;
- if( ( match_bit && !bit ) || ( !match_bit && bit ) )
+ if( match_bit != bit )
{
- while( ++i <= 8 )
- symbol = ( symbol << 1 ) | Rd_decode_bit( range_decoder, &bm[symbol] );
+ while( --i >= 0 )
+ symbol = ( symbol << 1 ) | Rd_decode_bit( rdec, &bm[symbol] );
break;
}
}
@@ -222,18 +199,16 @@ static inline void Led_init( struct Len_decoder * const len_decoder )
}
static inline int Led_decode( struct Len_decoder * const len_decoder,
- struct Range_decoder * const range_decoder,
+ struct Range_decoder * const rdec,
const int pos_state )
{
- if( Rd_decode_bit( range_decoder, &len_decoder->choice1 ) == 0 )
- return Rd_decode_tree( range_decoder, len_decoder->bm_low[pos_state],
- len_low_bits );
- if( Rd_decode_bit( range_decoder, &len_decoder->choice2 ) == 0 )
+ if( Rd_decode_bit( rdec, &len_decoder->choice1 ) == 0 )
+ return Rd_decode_tree( rdec, len_decoder->bm_low[pos_state], len_low_bits );
+ if( Rd_decode_bit( rdec, &len_decoder->choice2 ) == 0 )
return len_low_symbols +
- Rd_decode_tree( range_decoder, len_decoder->bm_mid[pos_state],
- len_mid_bits );
+ Rd_decode_tree( rdec, len_decoder->bm_mid[pos_state], len_mid_bits );
return len_low_symbols + len_mid_symbols +
- Rd_decode_tree( range_decoder, len_decoder->bm_high, len_high_bits );
+ Rd_decode_tree( rdec, len_decoder->bm_high, len_high_bits );
}
@@ -253,15 +228,15 @@ static inline int Lid_state( const int prev_byte )
{ return ( prev_byte >> ( 8 - literal_context_bits ) ); }
static inline uint8_t Lid_decode( struct Literal_decoder * const literal_decoder,
- struct Range_decoder * const range_decoder,
+ struct Range_decoder * const rdec,
const uint8_t prev_byte )
- { return Rd_decode_tree( range_decoder, literal_decoder->bm_literal[Lid_state(prev_byte)], 8 ); }
+ { return Rd_decode_tree( rdec, literal_decoder->bm_literal[Lid_state(prev_byte)], 8 ); }
static inline uint8_t Lid_decode_matched( struct Literal_decoder * const literal_decoder,
- struct Range_decoder * const range_decoder,
+ struct Range_decoder * const rdec,
const uint8_t prev_byte,
const uint8_t match_byte )
- { return Rd_decode_matched( range_decoder, literal_decoder->bm_literal[Lid_state(prev_byte)], match_byte ); }
+ { return Rd_decode_matched( rdec, literal_decoder->bm_literal[Lid_state(prev_byte)], match_byte ); }
struct LZ_decoder
@@ -286,7 +261,7 @@ struct LZ_decoder
Bit_model bm_dis[modeled_distances-end_dis_model];
Bit_model bm_align[dis_align_size];
- struct Range_decoder range_decoder;
+ struct Range_decoder * range_decoder;
struct Len_decoder len_decoder;
struct Len_decoder rep_match_len_decoder;
struct Literal_decoder literal_decoder;
@@ -335,7 +310,7 @@ bool LZd_verify_trailer( struct LZ_decoder * const decoder,
static inline void LZd_init( struct LZ_decoder * const decoder,
const File_header header,
- struct Input_buffer * const ibuf, const int outfd )
+ struct Range_decoder * const rdec, const int outfd )
{
decoder->partial_data_pos = 0;
decoder->format_version = Fh_version( header );
@@ -349,7 +324,7 @@ static inline void LZd_init( struct LZ_decoder * const decoder,
}
decoder->pos = 0;
decoder->stream_pos = 0;
- decoder->crc_ = 0xFFFFFFFF;
+ decoder->crc_ = 0xFFFFFFFFU;
decoder->outfd_ = outfd;
for( int i = 0; i < St_states; ++i )
@@ -372,7 +347,7 @@ static inline void LZd_init( struct LZ_decoder * const decoder,
for( int i = 0; i < dis_align_size; ++i )
Bm_init( &decoder->bm_align[i] );
- Rd_init( &decoder->range_decoder, ibuf );
+ decoder->range_decoder = rdec;
Led_init( &decoder->len_decoder );
Led_init( &decoder->rep_match_len_decoder );
Lid_init( &decoder->literal_decoder );
@@ -383,11 +358,13 @@ static inline void LZd_free( struct LZ_decoder * const decoder )
{ free( decoder->buffer ); decoder->buffer = 0; }
static inline uint32_t LZd_crc( struct LZ_decoder * const decoder )
- { return decoder->crc_ ^ 0xFFFFFFFF; }
+ { return decoder->crc_ ^ 0xFFFFFFFFU; }
+
int LZd_decode_member( struct LZ_decoder * const decoder,
struct Pretty_print * const pp );
static inline long long LZd_member_position( struct LZ_decoder * const decoder )
- { return Rd_member_position( &decoder->range_decoder ); }
+ { return Rd_member_position( decoder->range_decoder ); }
+
static inline long long LZd_data_position( struct LZ_decoder * const decoder )
{ return decoder->partial_data_pos + decoder->pos; }
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-02 19:15:23 +0000