contrib/xz/src/liblzma/lzma/lzma_encoder_private.h

   1 ///////////////////////////////////////////////////////////////////////////////
   2 //
   3 /// \file       lzma_encoder_private.h
   4 /// \brief      Private definitions for LZMA encoder
   5 ///
   6 //  Authors:    Igor Pavlov
   7 //              Lasse Collin
   8 //
   9 //  This file has been put into the public domain.
  10 //  You can do whatever you want with this file.
  11 //
  12 ///////////////////////////////////////////////////////////////////////////////
  13
  14 #ifndef LZMA_LZMA_ENCODER_PRIVATE_H
  15 #define LZMA_LZMA_ENCODER_PRIVATE_H
  16
  17 #include "lz_encoder.h"
  18 #include "range_encoder.h"
  19 #include "lzma_common.h"
  20 #include "lzma_encoder.h"
  21
  22
  23 // Macro to compare if the first two bytes in two buffers differ. This is
  24 // needed in lzma_lzma_optimum_*() to test if the match is at least
  25 // MATCH_LEN_MIN bytes. Unaligned access gives tiny gain so there's no
  26 // reason to not use it when it is supported.
  27 #ifdef TUKLIB_FAST_UNALIGNED_ACCESS
  28 #       define not_equal_16(a, b) \
  29                 (*(const uint16_t *)(a) != *(const uint16_t *)(b))
  30 #else
  31 #       define not_equal_16(a, b) \
  32                 ((a)[0] != (b)[0] || (a)[1] != (b)[1])
  33 #endif
  34
  35
  36 // Optimal - Number of entries in the optimum array.
  37 #define OPTS (1 << 12)
  38
  39
  40 typedef struct {
  41         probability choice;
  42         probability choice2;
  43         probability low[POS_STATES_MAX][LEN_LOW_SYMBOLS];
  44         probability mid[POS_STATES_MAX][LEN_MID_SYMBOLS];
  45         probability high[LEN_HIGH_SYMBOLS];
  46
  47         uint32_t prices[POS_STATES_MAX][LEN_SYMBOLS];
  48         uint32_t table_size;
  49         uint32_t counters[POS_STATES_MAX];
  50
  51 } lzma_length_encoder;
  52
  53
  54 typedef struct {
  55         lzma_lzma_state state;
  56
  57         bool prev_1_is_literal;
  58         bool prev_2;
  59
  60         uint32_t pos_prev_2;
  61         uint32_t back_prev_2;
  62
  63         uint32_t price;
  64         uint32_t pos_prev;  // pos_next;
  65         uint32_t back_prev;
  66
  67         uint32_t backs[REP_DISTANCES];
  68
  69 } lzma_optimal;
  70
  71
  72 struct lzma_coder_s {
  73         /// Range encoder
  74         lzma_range_encoder rc;
  75
  76         /// State
  77         lzma_lzma_state state;
  78
  79         /// The four most recent match distances
  80         uint32_t reps[REP_DISTANCES];
  81
  82         /// Array of match candidates
  83         lzma_match matches[MATCH_LEN_MAX + 1];
  84
  85         /// Number of match candidates in matches[]
  86         uint32_t matches_count;
  87
  88         /// Variable to hold the length of the longest match between calls
  89         /// to lzma_lzma_optimum_*().
  90         uint32_t longest_match_length;
  91
  92         /// True if using getoptimumfast
  93         bool fast_mode;
  94
  95         /// True if the encoder has been initialized by encoding the first
  96         /// byte as a literal.
  97         bool is_initialized;
  98
  99         /// True if the range encoder has been flushed, but not all bytes
 100         /// have been written to the output buffer yet.
 101         bool is_flushed;
 102
 103         uint32_t pos_mask;         ///< (1 << pos_bits) - 1
 104         uint32_t literal_context_bits;
 105         uint32_t literal_pos_mask;
 106
 107         // These are the same as in lzma_decoder.c. See comments there.
 108         probability literal[LITERAL_CODERS_MAX][LITERAL_CODER_SIZE];
 109         probability is_match[STATES][POS_STATES_MAX];
 110         probability is_rep[STATES];
 111         probability is_rep0[STATES];
 112         probability is_rep1[STATES];
 113         probability is_rep2[STATES];
 114         probability is_rep0_long[STATES][POS_STATES_MAX];
 115         probability pos_slot[LEN_TO_POS_STATES][POS_SLOTS];
 116         probability pos_special[FULL_DISTANCES - END_POS_MODEL_INDEX];
 117         probability pos_align[ALIGN_TABLE_SIZE];
 118
 119         // These are the same as in lzma_decoder.c except that the encoders
 120         // include also price tables.
 121         lzma_length_encoder match_len_encoder;
 122         lzma_length_encoder rep_len_encoder;
 123
 124         // Price tables
 125         uint32_t pos_slot_prices[LEN_TO_POS_STATES][POS_SLOTS];
 126         uint32_t distances_prices[LEN_TO_POS_STATES][FULL_DISTANCES];
 127         uint32_t dist_table_size;
 128         uint32_t match_price_count;
 129
 130         uint32_t align_prices[ALIGN_TABLE_SIZE];
 131         uint32_t align_price_count;
 132
 133         // Optimal
 134         uint32_t opts_end_index;
 135         uint32_t opts_current_index;
 136         lzma_optimal opts[OPTS];
 137 };
 138
 139
 140 extern void lzma_lzma_optimum_fast(
 141                 lzma_coder *restrict coder, lzma_mf *restrict mf,
 142                 uint32_t *restrict back_res, uint32_t *restrict len_res);
 143
 144 extern void lzma_lzma_optimum_normal(lzma_coder *restrict coder,
 145                 lzma_mf *restrict mf, uint32_t *restrict back_res,
 146                 uint32_t *restrict len_res, uint32_t position);
 147
 148 #endif