diff options
Diffstat (limited to 'fast_encoder.c')
| -rw-r--r-- | fast_encoder.c | 35 |
1 files changed, 14 insertions, 21 deletions
diff --git a/fast_encoder.c b/fast_encoder.c index bdcbb97..618c3d6 100644 --- a/fast_encoder.c +++ b/fast_encoder.c @@ -1,5 +1,5 @@ /* Lzlib - Compression library for the lzip format - Copyright (C) 2009-2021 Antonio Diaz Diaz. + Copyright (C) 2009-2022 Antonio Diaz Diaz. This library is free software. Redistribution and use in source and binary forms, with or without modification, are permitted provided @@ -20,25 +20,24 @@ static int FLZe_longest_match_len( struct FLZ_encoder * const fe, int * const distance ) { enum { len_limit = 16 }; - const uint8_t * const data = Mb_ptr_to_current_pos( &fe->eb.mb ); int32_t * ptr0 = fe->eb.mb.pos_array + fe->eb.mb.cyclic_pos; - const int pos1 = fe->eb.mb.pos + 1; - int maxlen = 0, newpos1, count; const int available = min( Mb_available_bytes( &fe->eb.mb ), max_match_len ); if( available < len_limit ) { *ptr0 = 0; return 0; } + const uint8_t * const data = Mb_ptr_to_current_pos( &fe->eb.mb ); fe->key4 = ( ( fe->key4 << 4 ) ^ data[3] ) & fe->eb.mb.key4_mask; - newpos1 = fe->eb.mb.prev_positions[fe->key4]; + const int pos1 = fe->eb.mb.pos + 1; + int newpos1 = fe->eb.mb.prev_positions[fe->key4]; fe->eb.mb.prev_positions[fe->key4] = pos1; + int maxlen = 0, count; for( count = 4; ; ) { - int32_t * newptr; int delta; if( newpos1 <= 0 || --count < 0 || ( delta = pos1 - newpos1 ) > fe->eb.mb.dictionary_size ) { *ptr0 = 0; break; } - newptr = fe->eb.mb.pos_array + + int32_t * const newptr = fe->eb.mb.pos_array + ( fe->eb.mb.cyclic_pos - delta + ( ( fe->eb.mb.cyclic_pos >= delta ) ? 0 : fe->eb.mb.dictionary_size + 1 ) ); @@ -71,11 +70,10 @@ static bool FLZe_encode_member( struct FLZ_encoder * const fe ) if( Mb_data_position( &fe->eb.mb ) == 0 && !Mb_data_finished( &fe->eb.mb ) ) /* encode first byte */ { - const uint8_t prev_byte = 0; - uint8_t cur_byte; if( !Mb_enough_available_bytes( &fe->eb.mb ) || !Re_enough_free_bytes( &fe->eb.renc ) ) return true; - cur_byte = Mb_peek( &fe->eb.mb, 0 ); + const uint8_t prev_byte = 0; + const uint8_t cur_byte = Mb_peek( &fe->eb.mb, 0 ); Re_encode_bit( &fe->eb.renc, &fe->eb.bm_match[*state][0], 0 ); LZeb_encode_literal( &fe->eb, prev_byte, cur_byte ); CRC32_update_byte( &fe->eb.crc, cur_byte ); @@ -86,13 +84,12 @@ static bool FLZe_encode_member( struct FLZ_encoder * const fe ) while( !Mb_data_finished( &fe->eb.mb ) && Re_member_position( &fe->eb.renc ) < fe->eb.member_size_limit ) { - int match_distance = 0; /* avoid warning from gcc 6.1.0 */ - int main_len, pos_state; - int len = 0; if( !Mb_enough_available_bytes( &fe->eb.mb ) || !Re_enough_free_bytes( &fe->eb.renc ) ) return true; - main_len = FLZe_longest_match_len( fe, &match_distance ); - pos_state = Mb_data_position( &fe->eb.mb ) & pos_state_mask; + int match_distance = 0; /* avoid warning from gcc 6.1.0 */ + const int main_len = FLZe_longest_match_len( fe, &match_distance ); + const int pos_state = Mb_data_position( &fe->eb.mb ) & pos_state_mask; + int len = 0; for( i = 0; i < num_rep_distances; ++i ) { @@ -109,11 +106,10 @@ static bool FLZe_encode_member( struct FLZ_encoder * const fe ) Re_encode_bit( &fe->eb.renc, &fe->eb.bm_len[*state][pos_state], 1 ); else { - int distance; Re_encode_bit( &fe->eb.renc, &fe->eb.bm_rep1[*state], rep > 1 ); if( rep > 1 ) Re_encode_bit( &fe->eb.renc, &fe->eb.bm_rep2[*state], rep > 2 ); - distance = fe->eb.reps[rep]; + const int distance = fe->eb.reps[rep]; for( i = rep; i > 0; --i ) fe->eb.reps[i] = fe->eb.reps[i-1]; fe->eb.reps[0] = distance; } @@ -138,7 +134,6 @@ static bool FLZe_encode_member( struct FLZ_encoder * const fe ) continue; } - { const uint8_t prev_byte = Mb_peek( &fe->eb.mb, 1 ); const uint8_t cur_byte = Mb_peek( &fe->eb.mb, 0 ); const uint8_t match_byte = Mb_peek( &fe->eb.mb, fe->eb.reps[0] + 1 ); @@ -169,12 +164,10 @@ static bool FLZe_encode_member( struct FLZ_encoder * const fe ) /* literal byte */ Re_encode_bit( &fe->eb.renc, &fe->eb.bm_match[*state][pos_state], 0 ); - if( St_is_char( *state ) ) + if( ( *state = St_set_char( *state ) ) < 4 ) LZeb_encode_literal( &fe->eb, prev_byte, cur_byte ); else LZeb_encode_matched( &fe->eb, prev_byte, cur_byte, match_byte ); - *state = St_set_char( *state ); - } } LZeb_try_full_flush( &fe->eb ); |