/* Lzlib - Compression library for the lzip format Copyright (C) 2009-2016 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 the Free Software Foundation, either version 2 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this library. If not, see . As a special exception, you may use this file as part of a free software library without restriction. Specifically, if other files instantiate templates or use macros or inline functions from this file, or you compile this file and link it with other files to produce an executable, this file does not by itself cause the resulting executable to be covered by the GNU General Public License. This exception does not however invalidate any other reasons why the executable file might be covered by the GNU General Public License. */ enum { price_shift_bits = 6, price_step_bits = 2 }; static const uint8_t dis_slots[1<<10] = { 0, 1, 2, 3, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19 }; static inline uint8_t get_slot( const unsigned dis ) { if( dis < (1 << 10) ) return dis_slots[dis]; if( dis < (1 << 19) ) return dis_slots[dis>> 9] + 18; if( dis < (1 << 28) ) return dis_slots[dis>>18] + 36; return dis_slots[dis>>27] + 54; } static const short prob_prices[bit_model_total >> price_step_bits] = { 640, 539, 492, 461, 438, 419, 404, 390, 379, 369, 359, 351, 343, 336, 330, 323, 318, 312, 307, 302, 298, 293, 289, 285, 281, 277, 274, 270, 267, 264, 261, 258, 255, 252, 250, 247, 244, 242, 239, 237, 235, 232, 230, 228, 226, 224, 222, 220, 218, 216, 214, 213, 211, 209, 207, 206, 204, 202, 201, 199, 198, 196, 195, 193, 192, 190, 189, 188, 186, 185, 184, 182, 181, 180, 178, 177, 176, 175, 174, 172, 171, 170, 169, 168, 167, 166, 165, 164, 163, 162, 161, 159, 158, 157, 157, 156, 155, 154, 153, 152, 151, 150, 149, 148, 147, 146, 145, 145, 144, 143, 142, 141, 140, 140, 139, 138, 137, 136, 136, 135, 134, 133, 133, 132, 131, 130, 130, 129, 128, 127, 127, 126, 125, 125, 124, 123, 123, 122, 121, 121, 120, 119, 119, 118, 117, 117, 116, 115, 115, 114, 114, 113, 112, 112, 111, 111, 110, 109, 109, 108, 108, 107, 106, 106, 105, 105, 104, 104, 103, 103, 102, 101, 101, 100, 100, 99, 99, 98, 98, 97, 97, 96, 96, 95, 95, 94, 94, 93, 93, 92, 92, 91, 91, 90, 90, 89, 89, 88, 88, 88, 87, 87, 86, 86, 85, 85, 84, 84, 83, 83, 83, 82, 82, 81, 81, 80, 80, 80, 79, 79, 78, 78, 77, 77, 77, 76, 76, 75, 75, 75, 74, 74, 73, 73, 73, 72, 72, 71, 71, 71, 70, 70, 70, 69, 69, 68, 68, 68, 67, 67, 67, 66, 66, 65, 65, 65, 64, 64, 64, 63, 63, 63, 62, 62, 61, 61, 61, 60, 60, 60, 59, 59, 59, 58, 58, 58, 57, 57, 57, 56, 56, 56, 55, 55, 55, 54, 54, 54, 53, 53, 53, 53, 52, 52, 52, 51, 51, 51, 50, 50, 50, 49, 49, 49, 48, 48, 48, 48, 47, 47, 47, 46, 46, 46, 45, 45, 45, 45, 44, 44, 44, 43, 43, 43, 43, 42, 42, 42, 41, 41, 41, 41, 40, 40, 40, 40, 39, 39, 39, 38, 38, 38, 38, 37, 37, 37, 37, 36, 36, 36, 35, 35, 35, 35, 34, 34, 34, 34, 33, 33, 33, 33, 32, 32, 32, 32, 31, 31, 31, 31, 30, 30, 30, 30, 29, 29, 29, 29, 28, 28, 28, 28, 27, 27, 27, 27, 26, 26, 26, 26, 26, 25, 25, 25, 25, 24, 24, 24, 24, 23, 23, 23, 23, 22, 22, 22, 22, 22, 21, 21, 21, 21, 20, 20, 20, 20, 20, 19, 19, 19, 19, 18, 18, 18, 18, 18, 17, 17, 17, 17, 17, 16, 16, 16, 16, 15, 15, 15, 15, 15, 14, 14, 14, 14, 14, 13, 13, 13, 13, 13, 12, 12, 12, 12, 12, 11, 11, 11, 11, 10, 10, 10, 10, 10, 9, 9, 9, 9, 9, 9, 8, 8, 8, 8, 8, 7, 7, 7, 7, 7, 6, 6, 6, 6, 6, 5, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1 }; static inline int get_price( const int probability ) { return prob_prices[probability >> price_step_bits]; } static inline int price0( const Bit_model probability ) { return get_price( probability ); } static inline int price1( const Bit_model probability ) { return get_price( bit_model_total - probability ); } static inline int price_bit( const Bit_model bm, const int bit ) { if( bit ) return price1( bm ); else return price0( bm ); } static inline int price_symbol( const Bit_model bm[], int symbol, const int num_bits ) { int price = 0; symbol |= ( 1 << num_bits ); while( symbol > 1 ) { const int bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit ); } return price; } static inline int price_symbol_reversed( const Bit_model bm[], int symbol, const int num_bits ) { int price = 0; int model = 1; int i; for( i = num_bits; i > 0; --i ) { const int bit = symbol & 1; price += price_bit( bm[model], bit ); model = ( model << 1 ) | bit; symbol >>= 1; } return price; } static inline int price_matched( const Bit_model bm[], int symbol, int match_byte ) { int price = 0; int mask = 0x100; symbol |= mask; do { int match_bit, bit; match_byte <<= 1; match_bit = match_byte & mask; symbol <<= 1; bit = symbol & 0x100; price += price_bit( bm[match_bit+(symbol>>9)+mask], bit ); mask &= ~(match_byte ^ symbol); /* if( match_bit != bit ) mask = 0; */ } while( symbol < 0x10000 ); return price; } struct Matchfinder_base { unsigned long long partial_data_pos; uint8_t * buffer; /* input buffer */ int32_t * prev_positions; /* 1 + last seen position of key. else 0 */ int32_t * pos_array; /* may be tree or chain */ int before_size; /* bytes to keep in buffer before dictionary */ int after_size; /* bytes to keep in buffer after pos */ int buffer_size; int dictionary_size; /* bytes to keep in buffer before pos */ int pos; /* current pos in buffer */ int cyclic_pos; /* cycles through [0, dictionary_size] */ int stream_pos; /* first byte not yet read from file */ int pos_limit; /* when reached, a new block must be read */ int key4_mask; int num_prev_positions23; int num_prev_positions; /* size of prev_positions */ int pos_array_size; bool at_stream_end; /* stream_pos shows real end of file */ bool flushing; }; static bool Mb_normalize_pos( struct Matchfinder_base * const mb ); static bool Mb_init( struct Matchfinder_base * const mb, const int before, const int dict_size, const int after_size, const int dict_factor, const int num_prev_positions23, const int pos_array_factor ); static inline void Mb_free( struct Matchfinder_base * const mb ) { free( mb->prev_positions ); free( mb->buffer ); } static inline uint8_t Mb_peek( const struct Matchfinder_base * const mb, const int distance ) { return mb->buffer[mb->pos-distance]; } static inline int Mb_available_bytes( const struct Matchfinder_base * const mb ) { return mb->stream_pos - mb->pos; } static inline unsigned long long Mb_data_position( const struct Matchfinder_base * const mb ) { return mb->partial_data_pos + mb->pos; } static inline void Mb_finish( struct Matchfinder_base * const mb ) { mb->at_stream_end = true; mb->flushing = false; } static inline bool Mb_data_finished( const struct Matchfinder_base * const mb ) { return mb->at_stream_end && !mb->flushing && mb->pos >= mb->stream_pos; } static inline bool Mb_flushing_or_end( const struct Matchfinder_base * const mb ) { return mb->at_stream_end || mb->flushing; } static inline int Mb_free_bytes( const struct Matchfinder_base * const mb ) { if( Mb_flushing_or_end( mb ) ) return 0; return mb->buffer_size - mb->stream_pos; } static inline bool Mb_enough_available_bytes( const struct Matchfinder_base * const mb ) { return ( mb->pos + mb->after_size <= mb->stream_pos || ( Mb_flushing_or_end( mb ) && mb->pos < mb->stream_pos ) ); } static inline const uint8_t * Mb_ptr_to_current_pos( const struct Matchfinder_base * const mb ) { return mb->buffer + mb->pos; } static int Mb_write_data( struct Matchfinder_base * const mb, const uint8_t * const inbuf, const int size ) { const int sz = min( mb->buffer_size - mb->stream_pos, size ); if( Mb_flushing_or_end( mb ) || sz <= 0 ) return 0; memcpy( mb->buffer + mb->stream_pos, inbuf, sz ); mb->stream_pos += sz; return sz; } static inline int Mb_true_match_len( const struct Matchfinder_base * const mb, const int index, const int distance, int len_limit ) { const uint8_t * const data = mb->buffer + mb->pos + index; int i = 0; if( index + len_limit > Mb_available_bytes( mb ) ) len_limit = Mb_available_bytes( mb ) - index; while( i < len_limit && data[i-distance] == data[i] ) ++i; return i; } static inline bool Mb_move_pos( struct Matchfinder_base * const mb ) { if( ++mb->cyclic_pos > mb->dictionary_size ) mb->cyclic_pos = 0; if( ++mb->pos >= mb->pos_limit ) return Mb_normalize_pos( mb ); return true; } struct Range_encoder { struct Circular_buffer cb; unsigned min_free_bytes; uint64_t low; unsigned long long partial_member_pos; uint32_t range; unsigned ff_count; uint8_t cache; File_header header; }; static inline void Re_shift_low( struct Range_encoder * const renc ) { const bool carry = ( renc->low > 0xFFFFFFFFU ); if( carry || renc->low < 0xFF000000U ) { Cb_put_byte( &renc->cb, renc->cache + carry ); for( ; renc->ff_count > 0; --renc->ff_count ) Cb_put_byte( &renc->cb, 0xFF + carry ); renc->cache = renc->low >> 24; } else ++renc->ff_count; renc->low = ( renc->low & 0x00FFFFFFU ) << 8; } static inline void Re_reset( struct Range_encoder * const renc ) { int i; Cb_reset( &renc->cb ); renc->low = 0; renc->partial_member_pos = 0; renc->range = 0xFFFFFFFFU; renc->ff_count = 0; renc->cache = 0; for( i = 0; i < Fh_size; ++i ) Cb_put_byte( &renc->cb, renc->header[i] ); } static inline bool Re_init( struct Range_encoder * const renc, const unsigned dictionary_size, const unsigned min_free_bytes ) { if( !Cb_init( &renc->cb, 65536 + min_free_bytes ) ) return false; renc->min_free_bytes = min_free_bytes; Fh_set_magic( renc->header ); Fh_set_dictionary_size( renc->header, dictionary_size ); Re_reset( renc ); return true; } static inline void Re_free( struct Range_encoder * const renc ) { Cb_free( &renc->cb ); } static inline unsigned long long Re_member_position( const struct Range_encoder * const renc ) { return renc->partial_member_pos + Cb_used_bytes( &renc->cb ) + renc->ff_count; } static inline bool Re_enough_free_bytes( const struct Range_encoder * const renc ) { return Cb_free_bytes( &renc->cb ) >= renc->min_free_bytes + renc->ff_count; } static inline int Re_read_data( struct Range_encoder * const renc, uint8_t * const out_buffer, const int out_size ) { const int size = Cb_read_data( &renc->cb, out_buffer, out_size ); if( size > 0 ) renc->partial_member_pos += size; return size; } static inline void Re_flush( struct Range_encoder * const renc ) { int i; for( i = 0; i < 5; ++i ) Re_shift_low( renc ); renc->low = 0; renc->range = 0xFFFFFFFFU; renc->ff_count = 0; renc->cache = 0; } static inline void Re_encode( struct Range_encoder * const renc, const int symbol, const int num_bits ) { int i; for( i = num_bits - 1; i >= 0; --i ) { renc->range >>= 1; if( (symbol >> i) & 1 ) renc->low += renc->range; if( renc->range <= 0x00FFFFFFU ) { renc->range <<= 8; Re_shift_low( renc ); } } } static inline void Re_encode_bit( struct Range_encoder * const renc, Bit_model * const probability, const int bit ) { const uint32_t bound = ( renc->range >> bit_model_total_bits ) * *probability; if( !bit ) { renc->range = bound; *probability += (bit_model_total - *probability) >> bit_model_move_bits; } else { renc->low += bound; renc->range -= bound; *probability -= *probability >> bit_model_move_bits; } if( renc->range <= 0x00FFFFFFU ) { renc->range <<= 8; Re_shift_low( renc ); } } static inline void Re_encode_tree( struct Range_encoder * const renc, Bit_model bm[], const int symbol, const int num_bits ) { int mask = ( 1 << ( num_bits - 1 ) ); int model = 1; int i; for( i = num_bits; i > 0; --i, mask >>= 1 ) { const int bit = ( symbol & mask ); Re_encode_bit( renc, &bm[model], bit ); model <<= 1; if( bit ) model |= 1; } } static inline void Re_encode_tree_reversed( struct Range_encoder * const renc, Bit_model bm[], int symbol, const int num_bits ) { int model = 1; int i; for( i = num_bits; i > 0; --i ) { const int bit = symbol & 1; Re_encode_bit( renc, &bm[model], bit ); model = ( model << 1 ) | bit; symbol >>= 1; } } static inline void Re_encode_matched( struct Range_encoder * const renc, Bit_model bm[], int symbol, int match_byte ) { int mask = 0x100; symbol |= mask; do { int match_bit, bit; match_byte <<= 1; match_bit = match_byte & mask; symbol <<= 1; bit = symbol & 0x100; Re_encode_bit( renc, &bm[match_bit+(symbol>>9)+mask], bit ); mask &= ~(match_byte ^ symbol); /* if( match_bit != bit ) mask = 0; */ } while( symbol < 0x10000 ); } static inline void Re_encode_len( struct Range_encoder * const renc, struct Len_model * const lm, int symbol, const int pos_state ) { bool bit = ( ( symbol -= min_match_len ) >= len_low_symbols ); Re_encode_bit( renc, &lm->choice1, bit ); if( !bit ) Re_encode_tree( renc, lm->bm_low[pos_state], symbol, len_low_bits ); else { bit = ( symbol >= len_low_symbols + len_mid_symbols ); Re_encode_bit( renc, &lm->choice2, bit ); if( !bit ) Re_encode_tree( renc, lm->bm_mid[pos_state], symbol - len_low_symbols, len_mid_bits ); else Re_encode_tree( renc, lm->bm_high, symbol - len_low_symbols - len_mid_symbols, len_high_bits ); } } enum { max_marker_size = 16, num_rep_distances = 4 }; /* must be 4 */ struct LZ_encoder_base { struct Matchfinder_base mb; unsigned long long member_size_limit; uint32_t crc; Bit_model bm_literal[1<mb, before, dict_size, after_size, dict_factor, num_prev_positions23, pos_array_factor ) ) return false; if( !Re_init( &eb->renc, eb->mb.dictionary_size, min_free_bytes ) ) return false; LZeb_reset( eb, member_size ); return true; } static inline bool LZeb_member_finished( const struct LZ_encoder_base * const eb ) { return ( eb->member_finished && !Cb_used_bytes( &eb->renc.cb ) ); } static inline void LZeb_free( struct LZ_encoder_base * const eb ) { Re_free( &eb->renc ); Mb_free( &eb->mb ); } static inline unsigned LZeb_crc( const struct LZ_encoder_base * const eb ) { return eb->crc ^ 0xFFFFFFFFU; } static inline int LZeb_price_literal( const struct LZ_encoder_base * const eb, uint8_t prev_byte, uint8_t symbol ) { return price_symbol( eb->bm_literal[get_lit_state(prev_byte)], symbol, 8 ); } static inline int LZeb_price_matched( const struct LZ_encoder_base * const eb, uint8_t prev_byte, uint8_t symbol, uint8_t match_byte ) { return price_matched( eb->bm_literal[get_lit_state(prev_byte)], symbol, match_byte ); } static inline void LZeb_encode_literal( struct LZ_encoder_base * const eb, uint8_t prev_byte, uint8_t symbol ) { Re_encode_tree( &eb->renc, eb->bm_literal[get_lit_state(prev_byte)], symbol, 8 ); } static inline void LZeb_encode_matched( struct LZ_encoder_base * const eb, uint8_t prev_byte, uint8_t symbol, uint8_t match_byte ) { Re_encode_matched( &eb->renc, eb->bm_literal[get_lit_state(prev_byte)], symbol, match_byte ); } static inline void LZeb_encode_pair( struct LZ_encoder_base * const eb, const unsigned dis, const int len, const int pos_state ) { const int dis_slot = get_slot( dis ); Re_encode_len( &eb->renc, &eb->match_len_model, len, pos_state ); Re_encode_tree( &eb->renc, eb->bm_dis_slot[get_len_state(len)], dis_slot, dis_slot_bits ); if( dis_slot >= start_dis_model ) { const int direct_bits = ( dis_slot >> 1 ) - 1; const unsigned base = ( 2 | ( dis_slot & 1 ) ) << direct_bits; const unsigned direct_dis = dis - base; if( dis_slot < end_dis_model ) Re_encode_tree_reversed( &eb->renc, eb->bm_dis + base - dis_slot - 1, direct_dis, direct_bits ); else { Re_encode( &eb->renc, direct_dis >> dis_align_bits, direct_bits - dis_align_bits ); Re_encode_tree_reversed( &eb->renc, eb->bm_align, direct_dis, dis_align_bits ); } } }