// * SPDX-License-Identifier:	GPL-2.0+
/* LzmaDec.c -- LZMA Decoder
2009-09-20 : Igor Pavlov : Public domain */

#include <config.h>
#include <common.h>
/* #include <watchdog.h> */
#include "LzmaDec.h"

/* #include <linux/string.h> */

#define kNumTopBits 24
#define kTopValue ((UInt32)1 << kNumTopBits)

#define kNumBitModelTotalBits 11
#define kBitModelTotal (1 << kNumBitModelTotalBits)
#define kNumMoveBits 5

#define RC_INIT_SIZE 5

#define NORMALIZE                                                              \
	if (range < kTopValue) {                                               \
		range <<= 8;                                                   \
		code = (code << 8) | (*buf++);                                 \
	}

#define IF_BIT_0(p)                                                            \
	ttt = *(p);                                                            \
	NORMALIZE;                                                             \
	bound = (range >> kNumBitModelTotalBits) * ttt;                        \
	if (code < bound)
#define UPDATE_0(p)                                                            \
	range = bound;                                                         \
	*(p)  = (CLzmaProb)(ttt + ((kBitModelTotal - ttt) >> kNumMoveBits));
#define UPDATE_1(p)                                                            \
	range -= bound;                                                        \
	code -= bound;                                                         \
	*(p) = (CLzmaProb)(ttt - (ttt >> kNumMoveBits));
#define GET_BIT2(p, i, A0, A1)                                                 \
	IF_BIT_0(p)                                                            \
	{                                                                      \
		UPDATE_0(p);                                                   \
		i = (i + i);                                                   \
		A0;                                                            \
	}                                                                      \
	else {                                                                      \
		UPDATE_1(p);                                                   \
		i = (i + i) + 1;                                               \
		A1;                                                            \
	}
#define GET_BIT(p, i) GET_BIT2(p, i, ;, ;)

#define TREE_GET_BIT(probs, i)                                                 \
	{                                                                      \
		GET_BIT((probs + i), i);                                       \
	}
#define TREE_DECODE(probs, limit, i)                                           \
	{                                                                      \
		i = 1;                                                         \
		do {                                                           \
			TREE_GET_BIT(probs, i);                                \
		} while (i < limit);                                           \
		i -= limit;                                                    \
	}

/* #define _LZMA_SIZE_OPT */

#ifdef _LZMA_SIZE_OPT
#define TREE_6_DECODE(probs, i) TREE_DECODE(probs, (1 << 6), i)
#else
#define TREE_6_DECODE(probs, i)                                                \
	{                                                                      \
		i = 1;                                                         \
		TREE_GET_BIT(probs, i);                                        \
		TREE_GET_BIT(probs, i);                                        \
		TREE_GET_BIT(probs, i);                                        \
		TREE_GET_BIT(probs, i);                                        \
		TREE_GET_BIT(probs, i);                                        \
		TREE_GET_BIT(probs, i);                                        \
		i -= 0x40;                                                     \
	}
#endif

#define NORMALIZE_CHECK                                                        \
	if (range < kTopValue) {                                               \
		if (buf >= bufLimit)                                           \
			return DUMMY_ERROR;                                    \
		range <<= 8;                                                   \
		code = (code << 8) | (*buf++);                                 \
	}

#define IF_BIT_0_CHECK(p)                                                      \
	ttt = *(p);                                                            \
	NORMALIZE_CHECK;                                                       \
	bound = (range >> kNumBitModelTotalBits) * ttt;                        \
	if (code < bound)
#define UPDATE_0_CHECK range = bound;
#define UPDATE_1_CHECK                                                         \
	range -= bound;                                                        \
	code -= bound;
#define GET_BIT2_CHECK(p, i, A0, A1)                                           \
	IF_BIT_0_CHECK(p)                                                      \
	{                                                                      \
		UPDATE_0_CHECK;                                                \
		i = (i + i);                                                   \
		A0;                                                            \
	}                                                                      \
	else {                                                                      \
		UPDATE_1_CHECK;                                                \
		i = (i + i) + 1;                                               \
		A1;                                                            \
	}
#define GET_BIT_CHECK(p, i) GET_BIT2_CHECK(p, i, ;, ;)
#define TREE_DECODE_CHECK(probs, limit, i)                                     \
	{                                                                      \
		i = 1;                                                         \
		do {                                                           \
			GET_BIT_CHECK(probs + i, i)                            \
		} while (i < limit);                                           \
		i -= limit;                                                    \
	}

#define kNumPosBitsMax 4
#define kNumPosStatesMax (1 << kNumPosBitsMax)

#define kLenNumLowBits 3
#define kLenNumLowSymbols (1 << kLenNumLowBits)
#define kLenNumMidBits 3
#define kLenNumMidSymbols (1 << kLenNumMidBits)
#define kLenNumHighBits 8
#define kLenNumHighSymbols (1 << kLenNumHighBits)

#define LenChoice 0
#define LenChoice2 (LenChoice + 1)
#define LenLow (LenChoice2 + 1)
#define LenMid (LenLow + (kNumPosStatesMax << kLenNumLowBits))
#define LenHigh (LenMid + (kNumPosStatesMax << kLenNumMidBits))
#define kNumLenProbs (LenHigh + kLenNumHighSymbols)

#define kNumStates 12
#define kNumLitStates 7

#define kStartPosModelIndex 4
#define kEndPosModelIndex 14
#define kNumFullDistances (1 << (kEndPosModelIndex >> 1))

#define kNumPosSlotBits 6
#define kNumLenToPosStates 4

#define kNumAlignBits 4
#define kAlignTableSize (1 << kNumAlignBits)

#define kMatchMinLen 2
#define kMatchSpecLenStart                                                     \
	(kMatchMinLen + kLenNumLowSymbols + kLenNumMidSymbols +                \
	 kLenNumHighSymbols)

#define IsMatch 0
#define IsRep (IsMatch + (kNumStates << kNumPosBitsMax))
#define IsRepG0 (IsRep + kNumStates)
#define IsRepG1 (IsRepG0 + kNumStates)
#define IsRepG2 (IsRepG1 + kNumStates)
#define IsRep0Long (IsRepG2 + kNumStates)
#define PosSlot (IsRep0Long + (kNumStates << kNumPosBitsMax))
#define SpecPos (PosSlot + (kNumLenToPosStates << kNumPosSlotBits))
#define Align (SpecPos + kNumFullDistances - kEndPosModelIndex)
#define LenCoder (Align + kAlignTableSize)
#define RepLenCoder (LenCoder + kNumLenProbs)
#define Literal (RepLenCoder + kNumLenProbs)

#define LZMA_BASE_SIZE 1846
#define LZMA_LIT_SIZE 768

#define LzmaProps_GetNumProbs(p)                                               \
	((UInt32)LZMA_BASE_SIZE + (LZMA_LIT_SIZE << ((p)->lc + (p)->lp)))

#if Literal != LZMA_BASE_SIZE
StopCompilingDueBUG
#endif

#define LZMA_DIC_MIN (1 << 12)

	/* First LZMA-symbol is always decoded.
And it decodes new LZMA-symbols while (buf < bufLimit), but "buf" is without last normalization
Out:
  Result:
    SZ_OK - OK
    SZ_ERROR_DATA - Error
  p->remainLen:
    < kMatchSpecLenStart : normal remain
    = kMatchSpecLenStart : finished
    = kMatchSpecLenStart + 1 : Flush marker
    = kMatchSpecLenStart + 2 : State Init Marker
*/

	static int MY_FAST_CALL
	LzmaDec_DecodeReal(CLzmaDec *p, SizeT limit, const Byte *bufLimit)
{
	CLzmaProb *probs = p->probs;

	unsigned state = p->state;
	UInt32 rep0 = p->reps[0], rep1 = p->reps[1], rep2 = p->reps[2],
	       rep3     = p->reps[3];
	unsigned pbMask = ((unsigned)1 << (p->prop.pb)) - 1;
	unsigned lpMask = ((unsigned)1 << (p->prop.lp)) - 1;
	unsigned lc     = p->prop.lc;

	Byte *dic	= p->dic;
	SizeT dicBufSize = p->dicBufSize;
	SizeT dicPos     = p->dicPos;

	UInt32 processedPos = p->processedPos;
	UInt32 checkDicSize = p->checkDicSize;
	unsigned len	= 0;

	const Byte *buf = p->buf;
	UInt32 range    = p->range;
	UInt32 code     = p->code;

	/* WATCHDOG_RESET(); */

	do {
		CLzmaProb *prob;
		UInt32 bound;
		unsigned ttt;
		unsigned posState = processedPos & pbMask;

		prob = probs + IsMatch + (state << kNumPosBitsMax) + posState;
		IF_BIT_0(prob)
		{
			unsigned symbol;
			UPDATE_0(prob);
			prob = probs + Literal;
			if (checkDicSize != 0 || processedPos != 0)
				prob += (LZMA_LIT_SIZE *
					 (((processedPos & lpMask) << lc) +
					  (dic[(dicPos == 0 ? dicBufSize :
							      dicPos) -
					       1] >>
					   (8 - lc))));

			if (state < kNumLitStates) {
				state -= (state < 4) ? state : 3;
				symbol = 1;

				/* WATCHDOG_RESET(); */

				do {
					GET_BIT(prob + symbol, symbol)
				} while (symbol < 0x100);
			} else {
				unsigned matchByte =
					p->dic[(dicPos - rep0) +
					       ((dicPos < rep0) ? dicBufSize :
								  0)];
				unsigned offs = 0x100;
				state -= (state < 10) ? 3 : 6;
				symbol = 1;

				/* WATCHDOG_RESET(); */

				do {
					unsigned bit;
					CLzmaProb *probLit;
					matchByte <<= 1;
					bit     = (matchByte & offs);
					probLit = prob + offs + bit + symbol;
					GET_BIT2(probLit, symbol, offs &= ~bit,
						 offs &= bit)
				} while (symbol < 0x100);
			}
			dic[dicPos++] = (Byte)symbol;
			processedPos++;
			continue;
		} else {
			UPDATE_1(prob);
			prob = probs + IsRep + state;
			IF_BIT_0(prob)
			{
				UPDATE_0(prob);
				state += kNumStates;
				prob = probs + LenCoder;
			} else {
				UPDATE_1(prob);
				if (checkDicSize == 0 && processedPos == 0)
					return SZ_ERROR_DATA;
				prob = probs + IsRepG0 + state;
				IF_BIT_0(prob)
				{
					UPDATE_0(prob);
					prob = probs + IsRep0Long +
					       (state << kNumPosBitsMax) +
					       posState;
					IF_BIT_0(prob)
					{
						UPDATE_0(prob);
						dic[dicPos] =
							dic[(dicPos - rep0) +
							    ((dicPos < rep0) ?
								     dicBufSize :
								     0)];
						dicPos++;
						processedPos++;
						state = state < kNumLitStates ?
								9 :
								11;
						continue;
					}
					UPDATE_1(prob);
				} else {
					UInt32 distance;
					UPDATE_1(prob);
					prob = probs + IsRepG1 + state;
					IF_BIT_0(prob)
					{
						UPDATE_0(prob);
						distance = rep1;
					} else {
						UPDATE_1(prob);
						prob = probs + IsRepG2 + state;
						IF_BIT_0(prob)
						{
							UPDATE_0(prob);
							distance = rep2;
						} else {
							UPDATE_1(prob);
							distance = rep3;
							rep3     = rep2;
						}
						rep2 = rep1;
					}
					rep1 = rep0;
					rep0 = distance;
				}
				state = state < kNumLitStates ? 8 : 11;
				prob  = probs + RepLenCoder;
			}
			{
				unsigned limit, offset;
				CLzmaProb *probLen = prob + LenChoice;
				IF_BIT_0(probLen)
				{
					UPDATE_0(probLen);
					probLen = prob + LenLow +
						  (posState << kLenNumLowBits);
					offset = 0;
					limit  = (1 << kLenNumLowBits);
				} else {
					UPDATE_1(probLen);
					probLen = prob + LenChoice2;
					IF_BIT_0(probLen)
					{
						UPDATE_0(probLen);
						probLen = prob + LenMid +
							  (posState
							   << kLenNumMidBits);
						offset = kLenNumLowSymbols;
						limit  = (1 << kLenNumMidBits);
					} else {
						UPDATE_1(probLen);
						probLen = prob + LenHigh;
						offset  = kLenNumLowSymbols +
							 kLenNumMidSymbols;
						limit = (1 << kLenNumHighBits);
					}
				}
				TREE_DECODE(probLen, limit, len);
				len += offset;
			}

			if (state >= kNumStates) {
				UInt32 distance;
				prob = probs + PosSlot +
				       ((len < kNumLenToPosStates ?
						 len :
						 kNumLenToPosStates - 1)
					<< kNumPosSlotBits);
				TREE_6_DECODE(prob, distance);
				if (distance >= kStartPosModelIndex) {
					unsigned posSlot = (unsigned)distance;
					int numDirectBits =
						(int)(((distance >> 1) - 1));
					distance = (2 | (distance & 1));
					if (posSlot < kEndPosModelIndex) {
						distance <<= numDirectBits;
						prob = probs + SpecPos +
						       distance - posSlot - 1;
						{
							UInt32 mask = 1;
							unsigned i  = 1;

							/* WATCHDOG_RESET(); */

							do {
								GET_BIT2(
									prob + i,
									i,
									;
									,
									distance |=
									mask);
								mask <<= 1;
							} while (
								--numDirectBits !=
								0);
						}
					} else {
						numDirectBits -= kNumAlignBits;

						/* WATCHDOG_RESET(); */

						do {
							NORMALIZE
							range >>= 1;

							{
								UInt32 t;
								code -= range;
								t = (0 -
								     ((UInt32)code >>
								      31)); /* (UInt32)((Int32)code >> 31) */
								distance =
									(distance
									 << 1) +
									(t + 1);
								code += range &
									t;
							}
							/*
						distance <<= 1;
						if (code >= range)
						{
						code -= range;
						distance |= 1;
						}
						*/
						} while (--numDirectBits != 0);
						prob = probs + Align;
						distance <<= kNumAlignBits;
						{
							unsigned i = 1;
							GET_BIT2(prob + i, i, ;
								 ,
								 distance |= 1);
							GET_BIT2(prob + i, i, ;
								 ,
								 distance |= 2);
							GET_BIT2(prob + i, i, ;
								 ,
								 distance |= 4);
							GET_BIT2(prob + i, i, ;
								 ,
								 distance |= 8);
						}
						if (distance ==
						    (UInt32)0xFFFFFFFF) {
							len += kMatchSpecLenStart;
							state -= kNumStates;
							break;
						}
					}
				}
				rep3 = rep2;
				rep2 = rep1;
				rep1 = rep0;
				rep0 = distance + 1;
				if (checkDicSize == 0) {
					if (distance >= processedPos)
						return SZ_ERROR_DATA;
				} else if (distance >= checkDicSize)
					return SZ_ERROR_DATA;
				state = (state < kNumStates + kNumLitStates) ?
						kNumLitStates :
						kNumLitStates + 3;
			}

			len += kMatchMinLen;

			if (limit == dicPos)
				return SZ_ERROR_DATA;
			{
				SizeT rem = limit - dicPos;
				unsigned curLen =
					((rem < len) ? (unsigned)rem : len);
				SizeT pos = (dicPos - rep0) +
					    ((dicPos < rep0) ? dicBufSize : 0);

				processedPos += curLen;

				len -= curLen;
				if (pos + curLen <= dicBufSize) {
					Byte *dest    = dic + dicPos;
					ptrdiff_t src = (ptrdiff_t)pos -
							(ptrdiff_t)dicPos;
					const Byte *lim = dest + curLen;
					dicPos += curLen;

					/* WATCHDOG_RESET(); */

					do
						*(dest) = (Byte) *(dest + src);
					while (++dest != lim);
				} else {
					/* WATCHDOG_RESET(); */

					do {
						dic[dicPos++] = dic[pos];
						if (++pos == dicBufSize)
							pos = 0;
					} while (--curLen != 0);
				}
			}
		}
	} while (dicPos < limit && buf < bufLimit);

	/* WATCHDOG_RESET(); */

	NORMALIZE;
	p->buf		= buf;
	p->range	= range;
	p->code		= code;
	p->remainLen    = len;
	p->dicPos       = dicPos;
	p->processedPos = processedPos;
	p->reps[0]      = rep0;
	p->reps[1]      = rep1;
	p->reps[2]      = rep2;
	p->reps[3]      = rep3;
	p->state	= state;

	return SZ_OK;
}

static void MY_FAST_CALL LzmaDec_WriteRem(CLzmaDec *p, SizeT limit)
{
	if (p->remainLen != 0 && p->remainLen < kMatchSpecLenStart) {
		Byte *dic	= p->dic;
		SizeT dicPos     = p->dicPos;
		SizeT dicBufSize = p->dicBufSize;
		unsigned len     = p->remainLen;
		UInt32 rep0      = p->reps[0];
		if (limit - dicPos < len)
			len = (unsigned)(limit - dicPos);

		if (p->checkDicSize == 0 &&
		    p->prop.dicSize - p->processedPos <= len)
			p->checkDicSize = p->prop.dicSize;

		p->processedPos += len;
		p->remainLen -= len;
		while (len-- != 0) {
			dic[dicPos] = dic[(dicPos - rep0) +
					  ((dicPos < rep0) ? dicBufSize : 0)];
			dicPos++;
		}
		p->dicPos = dicPos;
	}
}

static int MY_FAST_CALL LzmaDec_DecodeReal2(CLzmaDec *p, SizeT limit,
					    const Byte *bufLimit)
{
	do {
		SizeT limit2 = limit;
		if (p->checkDicSize == 0) {
			UInt32 rem = p->prop.dicSize - p->processedPos;
			if (limit - p->dicPos > rem)
				limit2 = p->dicPos + rem;
		}
		RINOK(LzmaDec_DecodeReal(p, limit2, bufLimit));
		if (p->processedPos >= p->prop.dicSize)
			p->checkDicSize = p->prop.dicSize;
		LzmaDec_WriteRem(p, limit);
	} while (p->dicPos < limit && p->buf < bufLimit &&
		 p->remainLen < kMatchSpecLenStart);

	if (p->remainLen > kMatchSpecLenStart) {
		p->remainLen = kMatchSpecLenStart;
	}
	return 0;
}

typedef enum {
	DUMMY_ERROR, /* unexpected end of input stream */
	DUMMY_LIT,
	DUMMY_MATCH,
	DUMMY_REP
} ELzmaDummy;

static ELzmaDummy LzmaDec_TryDummy(const CLzmaDec *p, const Byte *buf,
				   SizeT inSize)
{
	UInt32 range	 = p->range;
	UInt32 code	  = p->code;
	const Byte *bufLimit = buf + inSize;
	CLzmaProb *probs     = p->probs;
	unsigned state       = p->state;
	ELzmaDummy res;

	{
		CLzmaProb *prob;
		UInt32 bound;
		unsigned ttt;
		unsigned posState = (p->processedPos) & ((1 << p->prop.pb) - 1);

		prob = probs + IsMatch + (state << kNumPosBitsMax) + posState;
		IF_BIT_0_CHECK(prob)
		{
			UPDATE_0_CHECK

			/* if (bufLimit - buf >= 7) return DUMMY_LIT; */

			prob = probs + Literal;
			if (p->checkDicSize != 0 || p->processedPos != 0)
				prob += (LZMA_LIT_SIZE *
					 ((((p->processedPos) &
					    ((1 << (p->prop.lp)) - 1))
					   << p->prop.lc) +
					  (p->dic[(p->dicPos == 0 ?
							   p->dicBufSize :
							   p->dicPos) -
						  1] >>
					   (8 - p->prop.lc))));

			if (state < kNumLitStates) {
				unsigned symbol = 1;
				do {
					GET_BIT_CHECK(prob + symbol, symbol)
				} while (symbol < 0x100);
			} else {
				unsigned matchByte =
					p->dic[p->dicPos - p->reps[0] +
					       ((p->dicPos < p->reps[0]) ?
							p->dicBufSize :
							0)];
				unsigned offs   = 0x100;
				unsigned symbol = 1;
				do {
					unsigned bit;
					CLzmaProb *probLit;
					matchByte <<= 1;
					bit     = (matchByte & offs);
					probLit = prob + offs + bit + symbol;
					GET_BIT2_CHECK(probLit, symbol,
						       offs &= ~bit,
						       offs &= bit)
				} while (symbol < 0x100);
			}
			res = DUMMY_LIT;
		} else {
			unsigned len;
			UPDATE_1_CHECK;

			prob = probs + IsRep + state;
			IF_BIT_0_CHECK(prob)
			{
				UPDATE_0_CHECK;
				state = 0;
				prob  = probs + LenCoder;
				res   = DUMMY_MATCH;
			} else {
				UPDATE_1_CHECK;
				res  = DUMMY_REP;
				prob = probs + IsRepG0 + state;
				IF_BIT_0_CHECK(prob)
				{
					UPDATE_0_CHECK;
					prob = probs + IsRep0Long +
					       (state << kNumPosBitsMax) +
					       posState;
					IF_BIT_0_CHECK(prob)
					{
						UPDATE_0_CHECK;
						NORMALIZE_CHECK;
						return DUMMY_REP;
					} else {
						UPDATE_1_CHECK;
					}
				} else {
					UPDATE_1_CHECK;
					prob = probs + IsRepG1 + state;
					IF_BIT_0_CHECK(prob)
					{
						UPDATE_0_CHECK;
					} else {
						UPDATE_1_CHECK;
						prob = probs + IsRepG2 + state;
						IF_BIT_0_CHECK(prob)
						{
							UPDATE_0_CHECK;
						} else {
							UPDATE_1_CHECK;
						}
					}
				}
				state = kNumStates;
				prob  = probs + RepLenCoder;
			}
			{
				unsigned limit, offset;
				CLzmaProb *probLen = prob + LenChoice;
				IF_BIT_0_CHECK(probLen)
				{
					UPDATE_0_CHECK;
					probLen = prob + LenLow +
						  (posState << kLenNumLowBits);
					offset = 0;
					limit  = 1 << kLenNumLowBits;
				} else {
					UPDATE_1_CHECK;
					probLen = prob + LenChoice2;
					IF_BIT_0_CHECK(probLen)
					{
						UPDATE_0_CHECK;
						probLen = prob + LenMid +
							  (posState
							   << kLenNumMidBits);
						offset = kLenNumLowSymbols;
						limit  = 1 << kLenNumMidBits;
					} else {
						UPDATE_1_CHECK;
						probLen = prob + LenHigh;
						offset  = kLenNumLowSymbols +
							 kLenNumMidSymbols;
						limit = 1 << kLenNumHighBits;
					}
				}
				TREE_DECODE_CHECK(probLen, limit, len);
				len += offset;
			}

			if (state < 4) {
				unsigned posSlot;
				prob = probs + PosSlot +
				       ((len < kNumLenToPosStates ?
						 len :
						 kNumLenToPosStates - 1)
					<< kNumPosSlotBits);
				TREE_DECODE_CHECK(prob, 1 << kNumPosSlotBits,
						  posSlot);
				if (posSlot >= kStartPosModelIndex) {
					int numDirectBits =
						((posSlot >> 1) - 1);

					/* if (bufLimit - buf >= 8) return DUMMY_MATCH; */

					if (posSlot < kEndPosModelIndex) {
						prob = probs + SpecPos +
						       ((2 | (posSlot & 1))
							<< numDirectBits) -
						       posSlot - 1;
					} else {
						numDirectBits -= kNumAlignBits;
						do {
							NORMALIZE_CHECK
							range >>= 1;
							code -= range &
								(((code -
								   range) >>
								  31) -
								 1);
							/* if (code >= range) code -= range; */
						} while (--numDirectBits != 0);
						prob	  = probs + Align;
						numDirectBits = kNumAlignBits;
					}
					{
						unsigned i = 1;
						do {
							GET_BIT_CHECK(prob + i,
								      i);
						} while (--numDirectBits != 0);
					}
				}
			}
		}
	}
	NORMALIZE_CHECK;
	return res;
}

static void LzmaDec_InitRc(CLzmaDec *p, const Byte *data)
{
	p->code = ((UInt32)data[1] << 24) | ((UInt32)data[2] << 16) |
		  ((UInt32)data[3] << 8) | ((UInt32)data[4]);
	p->range     = 0xFFFFFFFF;
	p->needFlush = 0;
}

void LzmaDec_InitDicAndState(CLzmaDec *p, Bool initDic, Bool initState)
{
	p->needFlush   = 1;
	p->remainLen   = 0;
	p->tempBufSize = 0;

	if (initDic) {
		p->processedPos  = 0;
		p->checkDicSize  = 0;
		p->needInitState = 1;
	}
	if (initState)
		p->needInitState = 1;
}

void LzmaDec_Init(CLzmaDec *p)
{
	p->dicPos = 0;
	LzmaDec_InitDicAndState(p, True, True);
}

static void LzmaDec_InitStateReal(CLzmaDec *p)
{
	UInt32 numProbs =
		Literal + ((UInt32)LZMA_LIT_SIZE << (p->prop.lc + p->prop.lp));
	UInt32 i;
	CLzmaProb *probs = p->probs;
	for (i		 = 0; i < numProbs; i++)
		probs[i] = kBitModelTotal >> 1;
	p->reps[0] = p->reps[1] = p->reps[2] = p->reps[3] = 1;
	p->state					  = 0;
	p->needInitState				  = 0;
}

SRes LzmaDec_DecodeToDic(CLzmaDec *p, SizeT dicLimit, const Byte *src,
			 SizeT *srcLen, ELzmaFinishMode finishMode,
			 ELzmaStatus *status)
{
	SizeT inSize = *srcLen;
	(*srcLen)    = 0;
	LzmaDec_WriteRem(p, dicLimit);

	*status = LZMA_STATUS_NOT_SPECIFIED;

	while (p->remainLen != kMatchSpecLenStart) {
		int checkEndMarkNow;

		if (p->needFlush != 0) {
			for (; inSize > 0 && p->tempBufSize < RC_INIT_SIZE;
			     (*srcLen)++, inSize--)
				p->tempBuf[p->tempBufSize++] = *src++;
			if (p->tempBufSize < RC_INIT_SIZE) {
				*status = LZMA_STATUS_NEEDS_MORE_INPUT;
				return SZ_OK;
			}
			if (p->tempBuf[0] != 0)
				return SZ_ERROR_DATA;

			LzmaDec_InitRc(p, p->tempBuf);
			p->tempBufSize = 0;
		}

		checkEndMarkNow = 0;
		if (p->dicPos >= dicLimit) {
			if (p->remainLen == 0 && p->code == 0) {
				*status =
					LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK;
				return SZ_OK;
			}
			if (finishMode == LZMA_FINISH_ANY) {
				*status = LZMA_STATUS_NOT_FINISHED;
				return SZ_OK;
			}
			if (p->remainLen != 0) {
				*status = LZMA_STATUS_NOT_FINISHED;
				return SZ_ERROR_DATA;
			}
			checkEndMarkNow = 1;
		}

		if (p->needInitState)
			LzmaDec_InitStateReal(p);

		if (p->tempBufSize == 0) {
			SizeT processed;
			const Byte *bufLimit;
			if (inSize < LZMA_REQUIRED_INPUT_MAX ||
			    checkEndMarkNow) {
				int dummyRes = LzmaDec_TryDummy(p, src, inSize);
				if (dummyRes == DUMMY_ERROR) {
					memcpy(p->tempBuf, src, inSize);
					p->tempBufSize = (unsigned)inSize;
					(*srcLen) += inSize;
					*status = LZMA_STATUS_NEEDS_MORE_INPUT;
					return SZ_OK;
				}
				if (checkEndMarkNow &&
				    dummyRes != DUMMY_MATCH) {
					*status = LZMA_STATUS_NOT_FINISHED;
					return SZ_ERROR_DATA;
				}
				bufLimit = src;
			} else
				bufLimit =
					src + inSize - LZMA_REQUIRED_INPUT_MAX;
			p->buf = src;
			if (LzmaDec_DecodeReal2(p, dicLimit, bufLimit) != 0)
				return SZ_ERROR_DATA;
			processed = (SizeT)(p->buf - src);
			(*srcLen) += processed;
			src += processed;
			inSize -= processed;
		} else {
			unsigned rem = p->tempBufSize, lookAhead = 0;
			while (rem < LZMA_REQUIRED_INPUT_MAX &&
			       lookAhead < inSize)
				p->tempBuf[rem++] = src[lookAhead++];
			p->tempBufSize		  = rem;
			if (rem < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow) {
				int dummyRes =
					LzmaDec_TryDummy(p, p->tempBuf, rem);
				if (dummyRes == DUMMY_ERROR) {
					(*srcLen) += lookAhead;
					*status = LZMA_STATUS_NEEDS_MORE_INPUT;
					return SZ_OK;
				}
				if (checkEndMarkNow &&
				    dummyRes != DUMMY_MATCH) {
					*status = LZMA_STATUS_NOT_FINISHED;
					return SZ_ERROR_DATA;
				}
			}
			p->buf = p->tempBuf;
			if (LzmaDec_DecodeReal2(p, dicLimit, p->buf) != 0)
				return SZ_ERROR_DATA;
			lookAhead -= (rem - (unsigned)(p->buf - p->tempBuf));
			(*srcLen) += lookAhead;
			src += lookAhead;
			inSize -= lookAhead;
			p->tempBufSize = 0;
		}
	}
	if (p->code == 0)
		*status = LZMA_STATUS_FINISHED_WITH_MARK;
	return (p->code == 0) ? SZ_OK : SZ_ERROR_DATA;
}

SRes LzmaDec_DecodeToBuf(CLzmaDec *p, Byte *dest, SizeT *destLen,
			 const Byte *src, SizeT *srcLen,
			 ELzmaFinishMode finishMode, ELzmaStatus *status)
{
	SizeT outSize = *destLen;
	SizeT inSize  = *srcLen;
	*srcLen = *destLen = 0;
	for (;;) {
		SizeT inSizeCur = inSize, outSizeCur, dicPos;
		ELzmaFinishMode curFinishMode;
		SRes res;
		if (p->dicPos == p->dicBufSize)
			p->dicPos = 0;
		dicPos		  = p->dicPos;
		if (outSize > p->dicBufSize - dicPos) {
			outSizeCur    = p->dicBufSize;
			curFinishMode = LZMA_FINISH_ANY;
		} else {
			outSizeCur    = dicPos + outSize;
			curFinishMode = finishMode;
		}

		res = LzmaDec_DecodeToDic(p, outSizeCur, src, &inSizeCur,
					  curFinishMode, status);
		src += inSizeCur;
		inSize -= inSizeCur;
		*srcLen += inSizeCur;
		outSizeCur = p->dicPos - dicPos;
		memcpy(dest, p->dic + dicPos, outSizeCur);
		dest += outSizeCur;
		outSize -= outSizeCur;
		*destLen += outSizeCur;
		if (res != 0)
			return res;
		if (outSizeCur == 0 || outSize == 0)
			return SZ_OK;
	}
}

void LzmaDec_FreeProbs(CLzmaDec *p, ISzAlloc *alloc)
{
	alloc->Free(alloc, p->probs);
	p->probs = 0;
}

static void LzmaDec_FreeDict(CLzmaDec *p, ISzAlloc *alloc)
{
	alloc->Free(alloc, p->dic);
	p->dic = 0;
}

void LzmaDec_Free(CLzmaDec *p, ISzAlloc *alloc)
{
	LzmaDec_FreeProbs(p, alloc);
	LzmaDec_FreeDict(p, alloc);
}

SRes LzmaProps_Decode(CLzmaProps *p, const Byte *data, unsigned size)
{
	UInt32 dicSize;
	Byte d;

	if (size < LZMA_PROPS_SIZE)
		return SZ_ERROR_UNSUPPORTED;
	else
		dicSize = data[1] | ((UInt32)data[2] << 8) |
			  ((UInt32)data[3] << 16) | ((UInt32)data[4] << 24);

	if (dicSize < LZMA_DIC_MIN)
		dicSize = LZMA_DIC_MIN;
	p->dicSize      = dicSize;

	d = data[0];
	if (d >= (9 * 5 * 5))
		return SZ_ERROR_UNSUPPORTED;

	p->lc = d % 9;
	d /= 9;
	p->pb = d / 5;
	p->lp = d % 5;

	return SZ_OK;
}

static SRes LzmaDec_AllocateProbs2(CLzmaDec *p, const CLzmaProps *propNew,
				   ISzAlloc *alloc)
{
	UInt32 numProbs = LzmaProps_GetNumProbs(propNew);
	if (p->probs == 0 || numProbs != p->numProbs) {
		LzmaDec_FreeProbs(p, alloc);
		p->probs = (CLzmaProb *)alloc->Alloc(
			alloc, numProbs * sizeof(CLzmaProb));
		p->numProbs = numProbs;
		if (p->probs == 0)
			return SZ_ERROR_MEM;
	}
	return SZ_OK;
}

SRes LzmaDec_AllocateProbs(CLzmaDec *p, const Byte *props, unsigned propsSize,
			   ISzAlloc *alloc)
{
	CLzmaProps propNew;
	RINOK(LzmaProps_Decode(&propNew, props, propsSize));
	RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));
	p->prop = propNew;
	return SZ_OK;
}

SRes LzmaDec_Allocate(CLzmaDec *p, const Byte *props, unsigned propsSize,
		      ISzAlloc *alloc)
{
	CLzmaProps propNew;
	SizeT dicBufSize;
	RINOK(LzmaProps_Decode(&propNew, props, propsSize));
	RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));
	dicBufSize = propNew.dicSize;
	if (p->dic == 0 || dicBufSize != p->dicBufSize) {
		LzmaDec_FreeDict(p, alloc);
		p->dic = (Byte *)alloc->Alloc(alloc, dicBufSize);
		if (p->dic == 0) {
			LzmaDec_FreeProbs(p, alloc);
			return SZ_ERROR_MEM;
		}
	}
	p->dicBufSize = dicBufSize;
	p->prop       = propNew;
	return SZ_OK;
}

SRes LzmaDecode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen,
		const Byte *propData, unsigned propSize,
		ELzmaFinishMode finishMode, ELzmaStatus *status,
		ISzAlloc *alloc)
{
	CLzmaDec p;
	SRes res;
	SizeT inSize  = *srcLen;
	SizeT outSize = *destLen;
	*srcLen = *destLen = 0;
	if (inSize < RC_INIT_SIZE)
		return SZ_ERROR_INPUT_EOF;

	LzmaDec_Construct(&p);
	res = LzmaDec_AllocateProbs(&p, propData, propSize, alloc);
	if (res != 0)
		return res;
	p.dic	= dest;
	p.dicBufSize = outSize;

	LzmaDec_Init(&p);

	*srcLen = inSize;
	res = LzmaDec_DecodeToDic(&p, outSize, src, srcLen, finishMode, status);

	if (res == SZ_OK && *status == LZMA_STATUS_NEEDS_MORE_INPUT)
		res = SZ_ERROR_INPUT_EOF;

	(*destLen) = p.dicPos;
	LzmaDec_FreeProbs(&p, alloc);
	return res;
}
