namespace SharpCompress.Compressors.LZMA { internal abstract class Base { public const uint K_NUM_REP_DISTANCES = 4; public const uint K_NUM_STATES = 12; // static byte []kLiteralNextStates = {0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 4, 5}; // static byte []kMatchNextStates = {7, 7, 7, 7, 7, 7, 7, 10, 10, 10, 10, 10}; // static byte []kRepNextStates = {8, 8, 8, 8, 8, 8, 8, 11, 11, 11, 11, 11}; // static byte []kShortRepNextStates = {9, 9, 9, 9, 9, 9, 9, 11, 11, 11, 11, 11}; public struct State { public uint _index; public void Init() { _index = 0; } public void UpdateChar() { if (_index < 4) { _index = 0; } else if (_index < 10) { _index -= 3; } else { _index -= 6; } } public void UpdateMatch() { _index = (uint)(_index < 7 ? 7 : 10); } public void UpdateRep() { _index = (uint)(_index < 7 ? 8 : 11); } public void UpdateShortRep() { _index = (uint)(_index < 7 ? 9 : 11); } public bool IsCharState() { return _index < 7; } } public const int K_NUM_POS_SLOT_BITS = 6; public const int K_DIC_LOG_SIZE_MIN = 0; // public const int kDicLogSizeMax = 30; // public const uint kDistTableSizeMax = kDicLogSizeMax * 2; public const int K_NUM_LEN_TO_POS_STATES_BITS = 2; // it's for speed optimization public const uint K_NUM_LEN_TO_POS_STATES = 1 << K_NUM_LEN_TO_POS_STATES_BITS; public const uint K_MATCH_MIN_LEN = 2; public static uint GetLenToPosState(uint len) { len -= K_MATCH_MIN_LEN; if (len < K_NUM_LEN_TO_POS_STATES) { return len; } return K_NUM_LEN_TO_POS_STATES - 1; } public const int K_NUM_ALIGN_BITS = 4; public const uint K_ALIGN_TABLE_SIZE = 1 << K_NUM_ALIGN_BITS; public const uint K_ALIGN_MASK = (K_ALIGN_TABLE_SIZE - 1); public const uint K_START_POS_MODEL_INDEX = 4; public const uint K_END_POS_MODEL_INDEX = 14; public const uint K_NUM_POS_MODELS = K_END_POS_MODEL_INDEX - K_START_POS_MODEL_INDEX; public const uint K_NUM_FULL_DISTANCES = 1 << ((int)K_END_POS_MODEL_INDEX / 2); public const uint K_NUM_LIT_POS_STATES_BITS_ENCODING_MAX = 4; public const uint K_NUM_LIT_CONTEXT_BITS_MAX = 8; public const int K_NUM_POS_STATES_BITS_MAX = 4; public const uint K_NUM_POS_STATES_MAX = (1 << K_NUM_POS_STATES_BITS_MAX); public const int K_NUM_POS_STATES_BITS_ENCODING_MAX = 4; public const uint K_NUM_POS_STATES_ENCODING_MAX = (1 << K_NUM_POS_STATES_BITS_ENCODING_MAX); public const int K_NUM_LOW_LEN_BITS = 3; public const int K_NUM_MID_LEN_BITS = 3; public const int K_NUM_HIGH_LEN_BITS = 8; public const uint K_NUM_LOW_LEN_SYMBOLS = 1 << K_NUM_LOW_LEN_BITS; public const uint K_NUM_MID_LEN_SYMBOLS = 1 << K_NUM_MID_LEN_BITS; public const uint K_NUM_LEN_SYMBOLS = K_NUM_LOW_LEN_SYMBOLS + K_NUM_MID_LEN_SYMBOLS + (1 << K_NUM_HIGH_LEN_BITS); public const uint K_MATCH_MAX_LEN = K_MATCH_MIN_LEN + K_NUM_LEN_SYMBOLS - 1; } }