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Diffstat (limited to 'cpukit/libmisc/xz/xz_lzma2.h')
| -rw-r--r-- | cpukit/libmisc/xz/xz_lzma2.h | 204 |
1 files changed, 0 insertions, 204 deletions
diff --git a/cpukit/libmisc/xz/xz_lzma2.h b/cpukit/libmisc/xz/xz_lzma2.h deleted file mode 100644 index 071d67bee9..0000000000 --- a/cpukit/libmisc/xz/xz_lzma2.h +++ /dev/null @@ -1,204 +0,0 @@ -/* - * LZMA2 definitions - * - * Authors: Lasse Collin <lasse.collin@tukaani.org> - * Igor Pavlov <http://7-zip.org/> - * - * This file has been put into the public domain. - * You can do whatever you want with this file. - */ - -#ifndef XZ_LZMA2_H -#define XZ_LZMA2_H - -/* Range coder constants */ -#define RC_SHIFT_BITS 8 -#define RC_TOP_BITS 24 -#define RC_TOP_VALUE (1 << RC_TOP_BITS) -#define RC_BIT_MODEL_TOTAL_BITS 11 -#define RC_BIT_MODEL_TOTAL (1 << RC_BIT_MODEL_TOTAL_BITS) -#define RC_MOVE_BITS 5 - -/* - * Maximum number of position states. A position state is the lowest pb - * number of bits of the current uncompressed offset. In some places there - * are different sets of probabilities for different position states. - */ -#define POS_STATES_MAX (1 << 4) - -/* - * This enum is used to track which LZMA symbols have occurred most recently - * and in which order. This information is used to predict the next symbol. - * - * Symbols: - * - 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 symbol names are in from STATE_oldest_older_previous. REP means - * either short or long repeated match, and NONLIT means any non-literal. - */ -enum 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 -}; - -/* Total number of states */ -#define STATES 12 - -/* The lowest 7 states indicate that the previous state was a literal. */ -#define LIT_STATES 7 - -/* Indicate that the latest symbol was a literal. */ -static inline void lzma_state_literal(enum lzma_state *state) -{ - if (*state <= STATE_SHORTREP_LIT_LIT) - *state = STATE_LIT_LIT; - else if (*state <= STATE_LIT_SHORTREP) - *state -= 3; - else - *state -= 6; -} - -/* Indicate that the latest symbol was a match. */ -static inline void lzma_state_match(enum lzma_state *state) -{ - *state = *state < LIT_STATES ? STATE_LIT_MATCH : STATE_NONLIT_MATCH; -} - -/* Indicate that the latest state was a long repeated match. */ -static inline void lzma_state_long_rep(enum lzma_state *state) -{ - *state = *state < LIT_STATES ? STATE_LIT_LONGREP : STATE_NONLIT_REP; -} - -/* Indicate that the latest symbol was a short match. */ -static inline void lzma_state_short_rep(enum lzma_state *state) -{ - *state = *state < LIT_STATES ? STATE_LIT_SHORTREP : STATE_NONLIT_REP; -} - -/* Test if the previous symbol was a literal. */ -static inline bool lzma_state_is_literal(enum lzma_state state) -{ - return state < LIT_STATES; -} - -/* 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). - */ -#define LITERAL_CODER_SIZE 0x300 - -/* Maximum number of literal coders */ -#define LITERAL_CODERS_MAX (1 << 4) - -/* Minimum length of a match is two bytes. */ -#define MATCH_LEN_MIN 2 - -/* Match length is encoded with 4, 5, or 10 bits. - * - * Length Bits - * 2-9 4 = Choice=0 + 3 bits - * 10-17 5 = Choice=1 + Choice2=0 + 3 bits - * 18-273 10 = Choice=1 + Choice2=1 + 8 bits - */ -#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) - -/* - * Maximum length of a match is 273 which is a result of the encoding - * described above. - */ -#define MATCH_LEN_MAX (MATCH_LEN_MIN + LEN_SYMBOLS - 1) - -/* - * Different sets of probabilities are used for match distances that have - * very short match length: Lengths of 2, 3, and 4 bytes have a separate - * set of probabilities for each length. The matches with longer length - * use a shared set of probabilities. - */ -#define DIST_STATES 4 - -/* - * Get the index of the appropriate probability array for decoding - * the distance slot. - */ -static inline uint32_t lzma_get_dist_state(uint32_t len) -{ - return len < DIST_STATES + MATCH_LEN_MIN - ? len - MATCH_LEN_MIN : DIST_STATES - 1; -} - -/* - * The highest two bits of a 32-bit match distance are encoded using six bits. - * This six-bit value is called a distance slot. This way encoding a 32-bit - * value takes 6-36 bits, larger values taking more bits. - */ -#define DIST_SLOT_BITS 6 -#define DIST_SLOTS (1 << DIST_SLOT_BITS) - -/* Match distances up to 127 are fully encoded using probabilities. Since - * the highest two bits (distance slot) are always encoded using six bits, - * the distances 0-3 don't need any additional bits to encode, since the - * distance slot itself is the same as the actual distance. DIST_MODEL_START - * indicates the first distance slot where at least one additional bit is - * needed. - */ -#define DIST_MODEL_START 4 - -/* - * Match distances greater than 127 are encoded in three pieces: - * - distance slot: the highest two bits - * - direct bits: 2-26 bits below the highest two bits - * - alignment bits: four lowest bits - * - * Direct bits don't use any probabilities. - * - * The distance slot value of 14 is for distances 128-191. - */ -#define DIST_MODEL_END 14 - -/* Distance slots that indicate a distance <= 127. */ -#define FULL_DISTANCES_BITS (DIST_MODEL_END / 2) -#define FULL_DISTANCES (1 << FULL_DISTANCES_BITS) - -/* - * For match distances greater than 127, only the highest two bits and the - * lowest four bits (alignment) is encoded using probabilities. - */ -#define ALIGN_BITS 4 -#define ALIGN_SIZE (1 << ALIGN_BITS) -#define ALIGN_MASK (ALIGN_SIZE - 1) - -/* Total number of all probability variables */ -#define PROBS_TOTAL (1846 + LITERAL_CODERS_MAX * LITERAL_CODER_SIZE) - -/* - * LZMA remembers the four most recent match distances. Reusing these - * distances tends to take less space than re-encoding the actual - * distance value. - */ -#define REPS 4 - -#endif |