| /////////////////////////////////////////////////////////////////////////////// |
| // |
| /// \file lzma_common.h |
| /// \brief Private definitions common to LZMA encoder and decoder |
| // |
| // Copyright (C) 1999-2006 Igor Pavlov |
| // Copyright (C) 2007 Lasse Collin |
| // |
| // This library is free software; you can redistribute it and/or |
| // modify it under the terms of the GNU Lesser General Public |
| // License as published by the Free Software Foundation; either |
| // version 2.1 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 |
| // Lesser General Public License for more details. |
| // |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| #ifndef LZMA_LZMA_COMMON_H |
| #define LZMA_LZMA_COMMON_H |
| |
| #include "common.h" |
| #include "lzma_literal.h" |
| #include "range_common.h" |
| |
| |
| /////////////// |
| // Constants // |
| /////////////// |
| |
| #define REP_DISTANCES 4 |
| |
| #define POS_SLOT_BITS 6 |
| #define DICT_LOG_SIZE_MAX 30 |
| #define DIST_TABLE_SIZE_MAX (DICT_LOG_SIZE_MAX * 2) |
| #if (UINT32_C(1) << DICT_LOG_SIZE_MAX) != LZMA_DICTIONARY_SIZE_MAX |
| # error DICT_LOG_SIZE_MAX is inconsistent with LZMA_DICTIONARY_SIZE_MAX |
| #endif |
| |
| // 2 is for speed optimization |
| #define LEN_TO_POS_STATES_BITS 2 |
| #define LEN_TO_POS_STATES (1 << LEN_TO_POS_STATES_BITS) |
| |
| #define MATCH_MIN_LEN 2 |
| |
| #define ALIGN_BITS 4 |
| #define ALIGN_TABLE_SIZE (1 << ALIGN_BITS) |
| #define ALIGN_MASK (ALIGN_TABLE_SIZE - 1) |
| |
| #define START_POS_MODEL_INDEX 4 |
| #define END_POS_MODEL_INDEX 14 |
| #define POS_MODELS (END_POS_MODEL_INDEX - START_POS_MODEL_INDEX) |
| |
| #define FULL_DISTANCES_BITS (END_POS_MODEL_INDEX / 2) |
| #define FULL_DISTANCES (1 << FULL_DISTANCES_BITS) |
| |
| #define POS_STATES_MAX (1 << LZMA_POS_BITS_MAX) |
| |
| |
| // Length coder & Length price table encoder |
| #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 LEN_SPEC_SYMBOLS (LOW_LOW_SYMBOLS + LEN_MID_LEN_SYMBOLS) |
| #define MATCH_MAX_LEN (MATCH_MIN_LEN + LEN_SYMBOLS - 1) |
| |
| // Total number of probs in a Len Encoder |
| #define LEN_CODER_TOTAL_PROBS (LEN_HIGH_CODER + LEN_HIGH_SYMBOLS) |
| |
| // Price table size of Len Encoder |
| #define LEN_PRICES (LEN_SYMBOLS << LZMA_POS_BITS_MAX) |
| |
| // Special lengths used together with distance == UINT32_MAX |
| #define LEN_SPECIAL_EOPM MATCH_MIN_LEN |
| #define LEN_SPECIAL_FLUSH (LEN_SPECIAL_EOPM + 1) |
| |
| |
| // Optimal - Number of entries in the optimum array. |
| #define OPTS (1 << 12) |
| |
| |
| // Miscellaneous |
| #define INFINITY_PRICE 0x0FFFFFFF |
| |
| |
| //////////// |
| // Macros // |
| //////////// |
| |
| #define get_len_to_pos_state(len) \ |
| ((len) < LEN_TO_POS_STATES + MATCH_MIN_LEN \ |
| ? (len) - MATCH_MIN_LEN \ |
| : LEN_TO_POS_STATES - 1) |
| |
| |
| /////////// |
| // 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. |
| typedef enum { |
| 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; |
| |
| |
| /// 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 state was a literal. |
| #define update_literal(state) \ |
| state = ((state) <= STATE_SHORTREP_LIT_LIT \ |
| ? STATE_LIT_LIT \ |
| : ((state) <= STATE_LIT_SHORTREP \ |
| ? (state) - 3 \ |
| : (state) - 6)) |
| |
| /// Indicate that the latest state was a match. |
| #define update_match(state) \ |
| state = ((state) < LIT_STATES ? STATE_LIT_MATCH : STATE_NONLIT_MATCH) |
| |
| /// Indicate that the latest state was a long repeated match. |
| #define update_long_rep(state) \ |
| state = ((state) < LIT_STATES ? STATE_LIT_LONGREP : STATE_NONLIT_REP) |
| |
| /// Indicate that the latest state was a short match. |
| #define update_short_rep(state) \ |
| state = ((state) < LIT_STATES ? STATE_LIT_SHORTREP : STATE_NONLIT_REP) |
| |
| /// Test if the previous state was a literal. |
| #define is_literal_state(state) \ |
| ((state) < LIT_STATES) |
| |
| #endif |