Private definitions common to LZMA encoder and decoder. More...

#include "common.h"
#include "range_common.h"

Macros
#define	POS_STATES_MAX (1 << LZMA_PB_MAX)

#define	STATES 12
	Total number of states. More...

#define	LIT_STATES 7
	The lowest 7 states indicate that the previous state was a literal. More...

#define	update_literal(state)
	Indicate that the latest state was a literal. More...

#define	update_match(state) state = ((state) < LIT_STATES ? STATE_LIT_MATCH : STATE_NONLIT_MATCH)
	Indicate that the latest state was a match. More...

#define	update_long_rep(state) state = ((state) < LIT_STATES ? STATE_LIT_LONGREP : STATE_NONLIT_REP)
	Indicate that the latest state was a long repeated match. More...

#define	update_short_rep(state) state = ((state) < LIT_STATES ? STATE_LIT_SHORTREP : STATE_NONLIT_REP)
	Indicate that the latest state was a short match. More...

#define	is_literal_state(state) ((state) < LIT_STATES)
	Test if the previous state was a literal. More...

#define	LITERAL_CODER_SIZE 0x300

#define	LITERAL_CODERS_MAX (1 << LZMA_LCLP_MAX)
	Maximum number of literal coders. More...

#define	literal_subcoder(probs, lc, lp_mask, pos, prev_byte)

#define	MATCH_LEN_MIN 2

#define	LEN_LOW_BITS 3

#define	LEN_LOW_SYMBOLS (1 << LEN_LOW_BITS)

#define	LEN_MID_BITS 3

#define	LEN_MID_SYMBOLS (1 << LEN_MID_BITS)

#define	LEN_HIGH_BITS 8

#define	LEN_HIGH_SYMBOLS (1 << LEN_HIGH_BITS)

#define	LEN_SYMBOLS (LEN_LOW_SYMBOLS + LEN_MID_SYMBOLS + LEN_HIGH_SYMBOLS)

#define	MATCH_LEN_MAX (MATCH_LEN_MIN + LEN_SYMBOLS - 1)

#define	DIST_STATES 4

#define	get_dist_state(len)

#define	DIST_SLOT_BITS 6

#define	DIST_SLOTS (1 << DIST_SLOT_BITS)

#define	DIST_MODEL_START 4

#define	DIST_MODEL_END 14

#define	FULL_DISTANCES_BITS (DIST_MODEL_END / 2)

#define	FULL_DISTANCES (1 << FULL_DISTANCES_BITS)

#define	ALIGN_BITS 4

#define	ALIGN_SIZE (1 << ALIGN_BITS)

#define	ALIGN_MASK (ALIGN_SIZE - 1)

#define	REPS 4

Enumerations
enum	lzma_lzma_state { STATE_LIT_LIT , STATE_MATCH_LIT_LIT , STATE_REP_LIT_LIT , STATE_SHORTREP_LIT_LIT , STATE_MATCH_LIT , STATE_REP_LIT , STATE_SHORTREP_LIT , STATE_LIT_MATCH , STATE_LIT_LONGREP , STATE_LIT_SHORTREP , STATE_NONLIT_MATCH , STATE_NONLIT_REP }

Functions
static bool	is_lclppb_valid (const lzma_options_lzma *options)
	Validates lc, lp, and pb. More...

static void	literal_init (probability(*probs)[LITERAL_CODER_SIZE], uint32_t lc, uint32_t lp)

Detailed Description

Private definitions common to LZMA encoder and decoder.

Definition in file lzma_common.h.

Macro Definition Documentation

◆ ALIGN_BITS

#define ALIGN_BITS 4

Definition at line 217 of file lzma_common.h.

◆ ALIGN_MASK

#define ALIGN_MASK (ALIGN_SIZE - 1)

Definition at line 219 of file lzma_common.h.

◆ ALIGN_SIZE

#define ALIGN_SIZE (1 << ALIGN_BITS)

Definition at line 218 of file lzma_common.h.

◆ DIST_MODEL_END

#define DIST_MODEL_END 14

Definition at line 209 of file lzma_common.h.

◆ DIST_MODEL_START

#define DIST_MODEL_START 4

Definition at line 198 of file lzma_common.h.

◆ DIST_SLOT_BITS

#define DIST_SLOT_BITS 6

Definition at line 189 of file lzma_common.h.

◆ DIST_SLOTS

#define DIST_SLOTS (1 << DIST_SLOT_BITS)

Definition at line 190 of file lzma_common.h.

◆ DIST_STATES

#define DIST_STATES 4

Definition at line 179 of file lzma_common.h.

◆ FULL_DISTANCES

#define FULL_DISTANCES (1 << FULL_DISTANCES_BITS)

Definition at line 213 of file lzma_common.h.

◆ FULL_DISTANCES_BITS

#define FULL_DISTANCES_BITS (DIST_MODEL_END / 2)

Definition at line 212 of file lzma_common.h.

◆ get_dist_state

#define get_dist_state ( len )

Value:

    ((len) < DIST_STATES + MATCH_LEN_MIN \
        ? (len) - MATCH_LEN_MIN \
        : DIST_STATES - 1)

Definition at line 182 of file lzma_common.h.

◆ is_literal_state

#define is_literal_state ( state ) ((state) < LIT_STATES)

Test if the previous state was a literal.

Definition at line 100 of file lzma_common.h.

◆ LEN_HIGH_BITS

#define LEN_HIGH_BITS 8

Definition at line 162 of file lzma_common.h.

◆ LEN_HIGH_SYMBOLS

#define LEN_HIGH_SYMBOLS (1 << LEN_HIGH_BITS)

Definition at line 163 of file lzma_common.h.

◆ LEN_LOW_BITS

#define LEN_LOW_BITS 3

Definition at line 158 of file lzma_common.h.

◆ LEN_LOW_SYMBOLS

#define LEN_LOW_SYMBOLS (1 << LEN_LOW_BITS)

Definition at line 159 of file lzma_common.h.

◆ LEN_MID_BITS

#define LEN_MID_BITS 3

Definition at line 160 of file lzma_common.h.

◆ LEN_MID_SYMBOLS

#define LEN_MID_SYMBOLS (1 << LEN_MID_BITS)

Definition at line 161 of file lzma_common.h.

◆ LEN_SYMBOLS

#define LEN_SYMBOLS (LEN_LOW_SYMBOLS + LEN_MID_SYMBOLS + LEN_HIGH_SYMBOLS)

Definition at line 164 of file lzma_common.h.

◆ LIT_STATES

#define LIT_STATES 7

The lowest 7 states indicate that the previous state was a literal.

Definition at line 76 of file lzma_common.h.

◆ LITERAL_CODER_SIZE

#define LITERAL_CODER_SIZE 0x300

Each literal coder is divided in three sections:

0x001-0x0FF: Without match byte
0x101-0x1FF: With match byte; match bit is 0
0x201-0x2FF: With match byte; match bit is 1

Match byte is used when the previous LZMA symbol was something else than a literal (that is, it was some kind of match).

Definition at line 115 of file lzma_common.h.

◆ LITERAL_CODERS_MAX

#define LITERAL_CODERS_MAX (1 << LZMA_LCLP_MAX)

Maximum number of literal coders.

Definition at line 118 of file lzma_common.h.

◆ literal_subcoder

#define literal_subcoder	(	probs,
		lc,
		lp_mask,
		pos,
		prev_byte
	)

Value:

((probs)[(((pos) & (lp_mask)) << (lc)) \

+ ((uint32_t)(prev_byte) >> (8U - (lc)))])

uint32_t

unsigned int uint32_t

Definition: sftypes.h:29

pos

int pos

Definition: main.c:11

Locate the literal coder for the next literal byte. The choice depends on

the lowest literal_pos_bits bits of the position of the current byte; and
the highest literal_context_bits bits of the previous byte.

Definition at line 124 of file lzma_common.h.

◆ MATCH_LEN_MAX

#define MATCH_LEN_MAX (MATCH_LEN_MIN + LEN_SYMBOLS - 1)

Definition at line 168 of file lzma_common.h.

◆ MATCH_LEN_MIN

#define MATCH_LEN_MIN 2

Definition at line 150 of file lzma_common.h.

◆ POS_STATES_MAX

#define POS_STATES_MAX (1 << LZMA_PB_MAX)

Maximum number of position states. A position state is the lowest pos bits number of bits of the current uncompressed offset. In some places there are different sets of probabilities for different pos states.

Definition at line 28 of file lzma_common.h.

◆ REPS

#define REPS 4

Definition at line 223 of file lzma_common.h.

◆ STATES

#define STATES 12

Total number of states.

Definition at line 73 of file lzma_common.h.

◆ update_literal

#define update_literal ( state )

Value:

    state = ((state) <= STATE_SHORTREP_LIT_LIT \
            ? STATE_LIT_LIT \
            : ((state) <= STATE_LIT_SHORTREP \
                ? (state) - 3 \
                : (state) - 6))

Indicate that the latest state was a literal.

Definition at line 80 of file lzma_common.h.

◆ update_long_rep

#define update_long_rep ( state ) state = ((state) < LIT_STATES ? STATE_LIT_LONGREP : STATE_NONLIT_REP)

Indicate that the latest state was a long repeated match.

Definition at line 92 of file lzma_common.h.

◆ update_match

#define update_match ( state ) state = ((state) < LIT_STATES ? STATE_LIT_MATCH : STATE_NONLIT_MATCH)

Indicate that the latest state was a match.

Definition at line 88 of file lzma_common.h.

◆ update_short_rep

#define update_short_rep ( state ) state = ((state) < LIT_STATES ? STATE_LIT_SHORTREP : STATE_NONLIT_REP)

Indicate that the latest state was a short match.

Definition at line 96 of file lzma_common.h.

Enumeration Type Documentation

◆ lzma_lzma_state

enum lzma_lzma_state

This enum is used to track which events have occurred most recently and in which order. This information is used to predict the next event.

Events:

Literal: One 8-bit byte
Match: Repeat a chunk of data at some distance
Long repeat: Multi-byte match at a recently seen distance
Short repeat: One-byte repeat at a recently seen distance

The event names are in from STATE_oldest_older_previous. REP means either short or long repeated match, and NONLIT means any non-literal.

Enumerator
STATE_LIT_LIT
STATE_MATCH_LIT_LIT
STATE_REP_LIT_LIT
STATE_SHORTREP_LIT_LIT
STATE_MATCH_LIT
STATE_REP_LIT
STATE_SHORTREP_LIT
STATE_LIT_MATCH
STATE_LIT_LONGREP
STATE_LIT_SHORTREP
STATE_NONLIT_MATCH
STATE_NONLIT_REP

Definition at line 56 of file lzma_common.h.

              {
     STATE_LIT_LIT,
     STATE_MATCH_LIT_LIT,
     STATE_REP_LIT_LIT,
     STATE_SHORTREP_LIT_LIT,
     STATE_MATCH_LIT,
     STATE_REP_LIT,
     STATE_SHORTREP_LIT,
     STATE_LIT_MATCH,
     STATE_LIT_LONGREP,
     STATE_LIT_SHORTREP,
     STATE_NONLIT_MATCH,
     STATE_NONLIT_REP,
 } lzma_lzma_state;

Function Documentation

◆ is_lclppb_valid()

static bool is_lclppb_valid ( const lzma_options_lzma * options )

inlinestatic

Validates lc, lp, and pb.

Definition at line 33 of file lzma_common.h.

 {
     return options->lc <= LZMA_LCLP_MAX && options->lp <= LZMA_LCLP_MAX
             && options->lc + options->lp <= LZMA_LCLP_MAX
             && options->pb <= LZMA_PB_MAX;
 }

References LZMA_LCLP_MAX, LZMA_PB_MAX, and options.

Referenced by is_options_valid(), lzma_decoder_init(), lzma_lzma_decoder_memusage(), and lzma_lzma_lclppb_encode().

◆ literal_init()

static void literal_init	(	probability(*)	probs[LITERAL_CODER_SIZE],
		uint32_t	lc,
		uint32_t	lp
	)

inlinestatic

Definition at line 130 of file lzma_common.h.

 {
     assert(lc + lp <= LZMA_LCLP_MAX);
  
     const uint32_t coders = 1U << (lc + lp);
  
     for (uint32_t i = 0; i < coders; ++i)
         for (uint32_t j = 0; j < LITERAL_CODER_SIZE; ++j)
             bit_reset(probs[i][j]);
  
     return;
 }

References assert(), bit_reset, i, LITERAL_CODER_SIZE, and LZMA_LCLP_MAX.

Referenced by lzma_decoder_reset(), and lzma_lzma_encoder_reset().

Macros

Enumerations

Functions

Detailed Description

Macro Definition Documentation

◆ ALIGN_BITS

◆ ALIGN_MASK

◆ ALIGN_SIZE

◆ DIST_MODEL_END

◆ DIST_MODEL_START

◆ DIST_SLOT_BITS

◆ DIST_SLOTS

◆ DIST_STATES

◆ FULL_DISTANCES

◆ FULL_DISTANCES_BITS

◆ get_dist_state

◆ is_literal_state

◆ LEN_HIGH_BITS

◆ LEN_HIGH_SYMBOLS

◆ LEN_LOW_BITS

◆ LEN_LOW_SYMBOLS

◆ LEN_MID_BITS

◆ LEN_MID_SYMBOLS

◆ LEN_SYMBOLS

◆ LIT_STATES

◆ LITERAL_CODER_SIZE

◆ LITERAL_CODERS_MAX

◆ literal_subcoder

◆ MATCH_LEN_MAX

◆ MATCH_LEN_MIN

◆ POS_STATES_MAX

◆ REPS

◆ STATES

◆ update_literal

◆ update_long_rep

◆ update_match

◆ update_short_rep

Enumeration Type Documentation

◆ lzma_lzma_state

Function Documentation

◆ is_lclppb_valid()

◆ literal_init()