File indexing completed on 2025-02-02 04:25:59

0001 /* LzmaDec.c -- LZMA Decoder
0002 2015-01-01 : Igor Pavlov : Public domain */
0003 
0004 #include "Precomp.h"
0005 
0006 #include "LzmaDec.h"
0007 
0008 #include <string.h>
0009 
0010 #define kNumTopBits 24
0011 #define kTopValue ((UInt32)1 << kNumTopBits)
0012 
0013 #define kNumBitModelTotalBits 11
0014 #define kBitModelTotal (1 << kNumBitModelTotalBits)
0015 #define kNumMoveBits 5
0016 
0017 #define RC_INIT_SIZE 5
0018 
0019 #define NORMALIZE if (range < kTopValue) { range <<= 8; code = (code << 8) | (*buf++); }
0020 
0021 #define IF_BIT_0(p) ttt = *(p); NORMALIZE; bound = (range >> kNumBitModelTotalBits) * ttt; if (code < bound)
0022 #define UPDATE_0(p) range = bound; *(p) = (CLzmaProb)(ttt + ((kBitModelTotal - ttt) >> kNumMoveBits));
0023 #define UPDATE_1(p) range -= bound; code -= bound; *(p) = (CLzmaProb)(ttt - (ttt >> kNumMoveBits));
0024 #define GET_BIT2(p, i, A0, A1) IF_BIT_0(p) \
0025   { UPDATE_0(p); i = (i + i); A0; } else \
0026   { UPDATE_1(p); i = (i + i) + 1; A1; }
0027 #define GET_BIT(p, i) GET_BIT2(p, i, ; , ;)
0028 
0029 #define TREE_GET_BIT(probs, i) { GET_BIT((probs + i), i); }
0030 #define TREE_DECODE(probs, limit, i) \
0031   { i = 1; do { TREE_GET_BIT(probs, i); } while (i < limit); i -= limit; }
0032 
0033 /* #define _LZMA_SIZE_OPT */
0034 
0035 #ifdef _LZMA_SIZE_OPT
0036 #define TREE_6_DECODE(probs, i) TREE_DECODE(probs, (1 << 6), i)
0037 #else
0038 #define TREE_6_DECODE(probs, i) \
0039   { i = 1; \
0040   TREE_GET_BIT(probs, i); \
0041   TREE_GET_BIT(probs, i); \
0042   TREE_GET_BIT(probs, i); \
0043   TREE_GET_BIT(probs, i); \
0044   TREE_GET_BIT(probs, i); \
0045   TREE_GET_BIT(probs, i); \
0046   i -= 0x40; }
0047 #endif
0048 
0049 #define NORMAL_LITER_DEC GET_BIT(prob + symbol, symbol)
0050 #define MATCHED_LITER_DEC \
0051   matchByte <<= 1; \
0052   bit = (matchByte & offs); \
0053   probLit = prob + offs + bit + symbol; \
0054   GET_BIT2(probLit, symbol, offs &= ~bit, offs &= bit)
0055 
0056 #define NORMALIZE_CHECK if (range < kTopValue) { if (buf >= bufLimit) return DUMMY_ERROR; range <<= 8; code = (code << 8) | (*buf++); }
0057 
0058 #define IF_BIT_0_CHECK(p) ttt = *(p); NORMALIZE_CHECK; bound = (range >> kNumBitModelTotalBits) * ttt; if (code < bound)
0059 #define UPDATE_0_CHECK range = bound;
0060 #define UPDATE_1_CHECK range -= bound; code -= bound;
0061 #define GET_BIT2_CHECK(p, i, A0, A1) IF_BIT_0_CHECK(p) \
0062   { UPDATE_0_CHECK; i = (i + i); A0; } else \
0063   { UPDATE_1_CHECK; i = (i + i) + 1; A1; }
0064 #define GET_BIT_CHECK(p, i) GET_BIT2_CHECK(p, i, ; , ;)
0065 #define TREE_DECODE_CHECK(probs, limit, i) \
0066   { i = 1; do { GET_BIT_CHECK(probs + i, i) } while (i < limit); i -= limit; }
0067 
0068 
0069 #define kNumPosBitsMax 4
0070 #define kNumPosStatesMax (1 << kNumPosBitsMax)
0071 
0072 #define kLenNumLowBits 3
0073 #define kLenNumLowSymbols (1 << kLenNumLowBits)
0074 #define kLenNumMidBits 3
0075 #define kLenNumMidSymbols (1 << kLenNumMidBits)
0076 #define kLenNumHighBits 8
0077 #define kLenNumHighSymbols (1 << kLenNumHighBits)
0078 
0079 #define LenChoice 0
0080 #define LenChoice2 (LenChoice + 1)
0081 #define LenLow (LenChoice2 + 1)
0082 #define LenMid (LenLow + (kNumPosStatesMax << kLenNumLowBits))
0083 #define LenHigh (LenMid + (kNumPosStatesMax << kLenNumMidBits))
0084 #define kNumLenProbs (LenHigh + kLenNumHighSymbols)
0085 
0086 
0087 #define kNumStates 12
0088 #define kNumLitStates 7
0089 
0090 #define kStartPosModelIndex 4
0091 #define kEndPosModelIndex 14
0092 #define kNumFullDistances (1 << (kEndPosModelIndex >> 1))
0093 
0094 #define kNumPosSlotBits 6
0095 #define kNumLenToPosStates 4
0096 
0097 #define kNumAlignBits 4
0098 #define kAlignTableSize (1 << kNumAlignBits)
0099 
0100 #define kMatchMinLen 2
0101 #define kMatchSpecLenStart (kMatchMinLen + kLenNumLowSymbols + kLenNumMidSymbols + kLenNumHighSymbols)
0102 
0103 #define IsMatch 0
0104 #define IsRep (IsMatch + (kNumStates << kNumPosBitsMax))
0105 #define IsRepG0 (IsRep + kNumStates)
0106 #define IsRepG1 (IsRepG0 + kNumStates)
0107 #define IsRepG2 (IsRepG1 + kNumStates)
0108 #define IsRep0Long (IsRepG2 + kNumStates)
0109 #define PosSlot (IsRep0Long + (kNumStates << kNumPosBitsMax))
0110 #define SpecPos (PosSlot + (kNumLenToPosStates << kNumPosSlotBits))
0111 #define Align (SpecPos + kNumFullDistances - kEndPosModelIndex)
0112 #define LenCoder (Align + kAlignTableSize)
0113 #define RepLenCoder (LenCoder + kNumLenProbs)
0114 #define Literal (RepLenCoder + kNumLenProbs)
0115 
0116 #define LZMA_BASE_SIZE 1846
0117 #define LZMA_LIT_SIZE 768
0118 
0119 #define LzmaProps_GetNumProbs(p) ((UInt32)LZMA_BASE_SIZE + (LZMA_LIT_SIZE << ((p)->lc + (p)->lp)))
0120 
0121 #if Literal != LZMA_BASE_SIZE
0122 StopCompilingDueBUG
0123 #endif
0124 
0125 #define LZMA_DIC_MIN (1 << 12)
0126 
0127 /* First LZMA-symbol is always decoded.
0128 And it decodes new LZMA-symbols while (buf < bufLimit), but "buf" is without last normalization
0129 Out:
0130   Result:
0131     SZ_OK - OK
0132     SZ_ERROR_DATA - Error
0133   p->remainLen:
0134     < kMatchSpecLenStart : normal remain
0135     = kMatchSpecLenStart : finished
0136     = kMatchSpecLenStart + 1 : Flush marker
0137     = kMatchSpecLenStart + 2 : State Init Marker
0138 */
0139 
0140 static int MY_FAST_CALL LzmaDec_DecodeReal(CLzmaDec *p, SizeT limit, const Byte *bufLimit)
0141 {
0142   CLzmaProb *probs = p->probs;
0143 
0144   unsigned state = p->state;
0145   UInt32 rep0 = p->reps[0], rep1 = p->reps[1], rep2 = p->reps[2], rep3 = p->reps[3];
0146   unsigned pbMask = ((unsigned)1 << (p->prop.pb)) - 1;
0147   unsigned lpMask = ((unsigned)1 << (p->prop.lp)) - 1;
0148   unsigned lc = p->prop.lc;
0149 
0150   Byte *dic = p->dic;
0151   SizeT dicBufSize = p->dicBufSize;
0152   SizeT dicPos = p->dicPos;
0153   
0154   UInt32 processedPos = p->processedPos;
0155   UInt32 checkDicSize = p->checkDicSize;
0156   unsigned len = 0;
0157 
0158   const Byte *buf = p->buf;
0159   UInt32 range = p->range;
0160   UInt32 code = p->code;
0161 
0162   do
0163   {
0164     CLzmaProb *prob;
0165     UInt32 bound;
0166     unsigned ttt;
0167     unsigned posState = processedPos & pbMask;
0168 
0169     prob = probs + IsMatch + (state << kNumPosBitsMax) + posState;
0170     IF_BIT_0(prob)
0171     {
0172       unsigned symbol;
0173       UPDATE_0(prob);
0174       prob = probs + Literal;
0175       if (checkDicSize != 0 || processedPos != 0)
0176         prob += (LZMA_LIT_SIZE * (((processedPos & lpMask) << lc) +
0177         (dic[(dicPos == 0 ? dicBufSize : dicPos) - 1] >> (8 - lc))));
0178 
0179       if (state < kNumLitStates)
0180       {
0181         state -= (state < 4) ? state : 3;
0182         symbol = 1;
0183         #ifdef _LZMA_SIZE_OPT
0184         do { NORMAL_LITER_DEC } while (symbol < 0x100);
0185         #else
0186         NORMAL_LITER_DEC
0187         NORMAL_LITER_DEC
0188         NORMAL_LITER_DEC
0189         NORMAL_LITER_DEC
0190         NORMAL_LITER_DEC
0191         NORMAL_LITER_DEC
0192         NORMAL_LITER_DEC
0193         NORMAL_LITER_DEC
0194         #endif
0195       }
0196       else
0197       {
0198         unsigned matchByte = dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];
0199         unsigned offs = 0x100;
0200         state -= (state < 10) ? 3 : 6;
0201         symbol = 1;
0202         #ifdef _LZMA_SIZE_OPT
0203         do
0204         {
0205           unsigned bit;
0206           CLzmaProb *probLit;
0207           MATCHED_LITER_DEC
0208         }
0209         while (symbol < 0x100);
0210         #else
0211         {
0212           unsigned bit;
0213           CLzmaProb *probLit;
0214           MATCHED_LITER_DEC
0215           MATCHED_LITER_DEC
0216           MATCHED_LITER_DEC
0217           MATCHED_LITER_DEC
0218           MATCHED_LITER_DEC
0219           MATCHED_LITER_DEC
0220           MATCHED_LITER_DEC
0221           MATCHED_LITER_DEC
0222         }
0223         #endif
0224       }
0225       dic[dicPos++] = (Byte)symbol;
0226       processedPos++;
0227       continue;
0228     }
0229     else
0230     {
0231       UPDATE_1(prob);
0232       prob = probs + IsRep + state;
0233       IF_BIT_0(prob)
0234       {
0235         UPDATE_0(prob);
0236         state += kNumStates;
0237         prob = probs + LenCoder;
0238       }
0239       else
0240       {
0241         UPDATE_1(prob);
0242         if (checkDicSize == 0 && processedPos == 0)
0243           return SZ_ERROR_DATA;
0244         prob = probs + IsRepG0 + state;
0245         IF_BIT_0(prob)
0246         {
0247           UPDATE_0(prob);
0248           prob = probs + IsRep0Long + (state << kNumPosBitsMax) + posState;
0249           IF_BIT_0(prob)
0250           {
0251             UPDATE_0(prob);
0252             dic[dicPos] = dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];
0253             dicPos++;
0254             processedPos++;
0255             state = state < kNumLitStates ? 9 : 11;
0256             continue;
0257           }
0258           UPDATE_1(prob);
0259         }
0260         else
0261         {
0262           UInt32 distance;
0263           UPDATE_1(prob);
0264           prob = probs + IsRepG1 + state;
0265           IF_BIT_0(prob)
0266           {
0267             UPDATE_0(prob);
0268             distance = rep1;
0269           }
0270           else
0271           {
0272             UPDATE_1(prob);
0273             prob = probs + IsRepG2 + state;
0274             IF_BIT_0(prob)
0275             {
0276               UPDATE_0(prob);
0277               distance = rep2;
0278             }
0279             else
0280             {
0281               UPDATE_1(prob);
0282               distance = rep3;
0283               rep3 = rep2;
0284             }
0285             rep2 = rep1;
0286           }
0287           rep1 = rep0;
0288           rep0 = distance;
0289         }
0290         state = state < kNumLitStates ? 8 : 11;
0291         prob = probs + RepLenCoder;
0292       }
0293       {
0294         unsigned limit, offset;
0295         CLzmaProb *probLen = prob + LenChoice;
0296         IF_BIT_0(probLen)
0297         {
0298           UPDATE_0(probLen);
0299           probLen = prob + LenLow + (posState << kLenNumLowBits);
0300           offset = 0;
0301           limit = (1 << kLenNumLowBits);
0302         }
0303         else
0304         {
0305           UPDATE_1(probLen);
0306           probLen = prob + LenChoice2;
0307           IF_BIT_0(probLen)
0308           {
0309             UPDATE_0(probLen);
0310             probLen = prob + LenMid + (posState << kLenNumMidBits);
0311             offset = kLenNumLowSymbols;
0312             limit = (1 << kLenNumMidBits);
0313           }
0314           else
0315           {
0316             UPDATE_1(probLen);
0317             probLen = prob + LenHigh;
0318             offset = kLenNumLowSymbols + kLenNumMidSymbols;
0319             limit = (1 << kLenNumHighBits);
0320           }
0321         }
0322         TREE_DECODE(probLen, limit, len);
0323         len += offset;
0324       }
0325 
0326       if (state >= kNumStates)
0327       {
0328         UInt32 distance;
0329         prob = probs + PosSlot +
0330             ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) << kNumPosSlotBits);
0331         TREE_6_DECODE(prob, distance);
0332         if (distance >= kStartPosModelIndex)
0333         {
0334           unsigned posSlot = (unsigned)distance;
0335           int numDirectBits = (int)(((distance >> 1) - 1));
0336           distance = (2 | (distance & 1));
0337           if (posSlot < kEndPosModelIndex)
0338           {
0339             distance <<= numDirectBits;
0340             prob = probs + SpecPos + distance - posSlot - 1;
0341             {
0342               UInt32 mask = 1;
0343               unsigned i = 1;
0344               do
0345               {
0346                 GET_BIT2(prob + i, i, ; , distance |= mask);
0347                 mask <<= 1;
0348               }
0349               while (--numDirectBits != 0);
0350             }
0351           }
0352           else
0353           {
0354             numDirectBits -= kNumAlignBits;
0355             do
0356             {
0357               NORMALIZE
0358               range >>= 1;
0359               
0360               {
0361                 UInt32 t;
0362                 code -= range;
0363                 t = (0 - ((UInt32)code >> 31)); /* (UInt32)((Int32)code >> 31) */
0364                 distance = (distance << 1) + (t + 1);
0365                 code += range & t;
0366               }
0367               /*
0368               distance <<= 1;
0369               if (code >= range)
0370               {
0371                 code -= range;
0372                 distance |= 1;
0373               }
0374               */
0375             }
0376             while (--numDirectBits != 0);
0377             prob = probs + Align;
0378             distance <<= kNumAlignBits;
0379             {
0380               unsigned i = 1;
0381               GET_BIT2(prob + i, i, ; , distance |= 1);
0382               GET_BIT2(prob + i, i, ; , distance |= 2);
0383               GET_BIT2(prob + i, i, ; , distance |= 4);
0384               GET_BIT2(prob + i, i, ; , distance |= 8);
0385             }
0386             if (distance == (UInt32)0xFFFFFFFF)
0387             {
0388               len += kMatchSpecLenStart;
0389               state -= kNumStates;
0390               break;
0391             }
0392           }
0393         }
0394         rep3 = rep2;
0395         rep2 = rep1;
0396         rep1 = rep0;
0397         rep0 = distance + 1;
0398         if (checkDicSize == 0)
0399         {
0400           if (distance >= processedPos)
0401             return SZ_ERROR_DATA;
0402         }
0403         else if (distance >= checkDicSize)
0404           return SZ_ERROR_DATA;
0405         state = (state < kNumStates + kNumLitStates) ? kNumLitStates : kNumLitStates + 3;
0406       }
0407 
0408       len += kMatchMinLen;
0409 
0410       if (limit == dicPos)
0411         return SZ_ERROR_DATA;
0412       {
0413         SizeT rem = limit - dicPos;
0414         unsigned curLen = ((rem < len) ? (unsigned)rem : len);
0415         SizeT pos = (dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0);
0416 
0417         processedPos += curLen;
0418 
0419         len -= curLen;
0420         if (pos + curLen <= dicBufSize)
0421         {
0422           Byte *dest = dic + dicPos;
0423           ptrdiff_t src = (ptrdiff_t)pos - (ptrdiff_t)dicPos;
0424           const Byte *lim = dest + curLen;
0425           dicPos += curLen;
0426           do
0427             *(dest) = (Byte)*(dest + src);
0428           while (++dest != lim);
0429         }
0430         else
0431         {
0432           do
0433           {
0434             dic[dicPos++] = dic[pos];
0435             if (++pos == dicBufSize)
0436               pos = 0;
0437           }
0438           while (--curLen != 0);
0439         }
0440       }
0441     }
0442   }
0443   while (dicPos < limit && buf < bufLimit);
0444   NORMALIZE;
0445   p->buf = buf;
0446   p->range = range;
0447   p->code = code;
0448   p->remainLen = len;
0449   p->dicPos = dicPos;
0450   p->processedPos = processedPos;
0451   p->reps[0] = rep0;
0452   p->reps[1] = rep1;
0453   p->reps[2] = rep2;
0454   p->reps[3] = rep3;
0455   p->state = state;
0456 
0457   return SZ_OK;
0458 }
0459 
0460 static void MY_FAST_CALL LzmaDec_WriteRem(CLzmaDec *p, SizeT limit)
0461 {
0462   if (p->remainLen != 0 && p->remainLen < kMatchSpecLenStart)
0463   {
0464     Byte *dic = p->dic;
0465     SizeT dicPos = p->dicPos;
0466     SizeT dicBufSize = p->dicBufSize;
0467     unsigned len = p->remainLen;
0468     UInt32 rep0 = p->reps[0];
0469     if (limit - dicPos < len)
0470       len = (unsigned)(limit - dicPos);
0471 
0472     if (p->checkDicSize == 0 && p->prop.dicSize - p->processedPos <= len)
0473       p->checkDicSize = p->prop.dicSize;
0474 
0475     p->processedPos += len;
0476     p->remainLen -= len;
0477     while (len != 0)
0478     {
0479       len--;
0480       dic[dicPos] = dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];
0481       dicPos++;
0482     }
0483     p->dicPos = dicPos;
0484   }
0485 }
0486 
0487 static int MY_FAST_CALL LzmaDec_DecodeReal2(CLzmaDec *p, SizeT limit, const Byte *bufLimit)
0488 {
0489   do
0490   {
0491     SizeT limit2 = limit;
0492     if (p->checkDicSize == 0)
0493     {
0494       UInt32 rem = p->prop.dicSize - p->processedPos;
0495       if (limit - p->dicPos > rem)
0496         limit2 = p->dicPos + rem;
0497     }
0498     RINOK(LzmaDec_DecodeReal(p, limit2, bufLimit));
0499     if (p->processedPos >= p->prop.dicSize)
0500       p->checkDicSize = p->prop.dicSize;
0501     LzmaDec_WriteRem(p, limit);
0502   }
0503   while (p->dicPos < limit && p->buf < bufLimit && p->remainLen < kMatchSpecLenStart);
0504 
0505   if (p->remainLen > kMatchSpecLenStart)
0506   {
0507     p->remainLen = kMatchSpecLenStart;
0508   }
0509   return 0;
0510 }
0511 
0512 typedef enum
0513 {
0514   DUMMY_ERROR, /* unexpected end of input stream */
0515   DUMMY_LIT,
0516   DUMMY_MATCH,
0517   DUMMY_REP
0518 } ELzmaDummy;
0519 
0520 static ELzmaDummy LzmaDec_TryDummy(const CLzmaDec *p, const Byte *buf, SizeT inSize)
0521 {
0522   UInt32 range = p->range;
0523   UInt32 code = p->code;
0524   const Byte *bufLimit = buf + inSize;
0525   CLzmaProb *probs = p->probs;
0526   unsigned state = p->state;
0527   ELzmaDummy res;
0528 
0529   {
0530     CLzmaProb *prob;
0531     UInt32 bound;
0532     unsigned ttt;
0533     unsigned posState = (p->processedPos) & ((1 << p->prop.pb) - 1);
0534 
0535     prob = probs + IsMatch + (state << kNumPosBitsMax) + posState;
0536     IF_BIT_0_CHECK(prob)
0537     {
0538       UPDATE_0_CHECK
0539 
0540       /* if (bufLimit - buf >= 7) return DUMMY_LIT; */
0541 
0542       prob = probs + Literal;
0543       if (p->checkDicSize != 0 || p->processedPos != 0)
0544         prob += (LZMA_LIT_SIZE *
0545           ((((p->processedPos) & ((1 << (p->prop.lp)) - 1)) << p->prop.lc) +
0546           (p->dic[(p->dicPos == 0 ? p->dicBufSize : p->dicPos) - 1] >> (8 - p->prop.lc))));
0547 
0548       if (state < kNumLitStates)
0549       {
0550         unsigned symbol = 1;
0551         do { GET_BIT_CHECK(prob + symbol, symbol) } while (symbol < 0x100);
0552       }
0553       else
0554       {
0555         unsigned matchByte = p->dic[p->dicPos - p->reps[0] +
0556             ((p->dicPos < p->reps[0]) ? p->dicBufSize : 0)];
0557         unsigned offs = 0x100;
0558         unsigned symbol = 1;
0559         do
0560         {
0561           unsigned bit;
0562           CLzmaProb *probLit;
0563           matchByte <<= 1;
0564           bit = (matchByte & offs);
0565           probLit = prob + offs + bit + symbol;
0566           GET_BIT2_CHECK(probLit, symbol, offs &= ~bit, offs &= bit)
0567         }
0568         while (symbol < 0x100);
0569       }
0570       res = DUMMY_LIT;
0571     }
0572     else
0573     {
0574       unsigned len;
0575       UPDATE_1_CHECK;
0576 
0577       prob = probs + IsRep + state;
0578       IF_BIT_0_CHECK(prob)
0579       {
0580         UPDATE_0_CHECK;
0581         state = 0;
0582         prob = probs + LenCoder;
0583         res = DUMMY_MATCH;
0584       }
0585       else
0586       {
0587         UPDATE_1_CHECK;
0588         res = DUMMY_REP;
0589         prob = probs + IsRepG0 + state;
0590         IF_BIT_0_CHECK(prob)
0591         {
0592           UPDATE_0_CHECK;
0593           prob = probs + IsRep0Long + (state << kNumPosBitsMax) + posState;
0594           IF_BIT_0_CHECK(prob)
0595           {
0596             UPDATE_0_CHECK;
0597             NORMALIZE_CHECK;
0598             return DUMMY_REP;
0599           }
0600           else
0601           {
0602             UPDATE_1_CHECK;
0603           }
0604         }
0605         else
0606         {
0607           UPDATE_1_CHECK;
0608           prob = probs + IsRepG1 + state;
0609           IF_BIT_0_CHECK(prob)
0610           {
0611             UPDATE_0_CHECK;
0612           }
0613           else
0614           {
0615             UPDATE_1_CHECK;
0616             prob = probs + IsRepG2 + state;
0617             IF_BIT_0_CHECK(prob)
0618             {
0619               UPDATE_0_CHECK;
0620             }
0621             else
0622             {
0623               UPDATE_1_CHECK;
0624             }
0625           }
0626         }
0627         state = kNumStates;
0628         prob = probs + RepLenCoder;
0629       }
0630       {
0631         unsigned limit, offset;
0632         CLzmaProb *probLen = prob + LenChoice;
0633         IF_BIT_0_CHECK(probLen)
0634         {
0635           UPDATE_0_CHECK;
0636           probLen = prob + LenLow + (posState << kLenNumLowBits);
0637           offset = 0;
0638           limit = 1 << kLenNumLowBits;
0639         }
0640         else
0641         {
0642           UPDATE_1_CHECK;
0643           probLen = prob + LenChoice2;
0644           IF_BIT_0_CHECK(probLen)
0645           {
0646             UPDATE_0_CHECK;
0647             probLen = prob + LenMid + (posState << kLenNumMidBits);
0648             offset = kLenNumLowSymbols;
0649             limit = 1 << kLenNumMidBits;
0650           }
0651           else
0652           {
0653             UPDATE_1_CHECK;
0654             probLen = prob + LenHigh;
0655             offset = kLenNumLowSymbols + kLenNumMidSymbols;
0656             limit = 1 << kLenNumHighBits;
0657           }
0658         }
0659         TREE_DECODE_CHECK(probLen, limit, len);
0660         len += offset;
0661       }
0662 
0663       if (state < 4)
0664       {
0665         unsigned posSlot;
0666         prob = probs + PosSlot +
0667             ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) <<
0668             kNumPosSlotBits);
0669         TREE_DECODE_CHECK(prob, 1 << kNumPosSlotBits, posSlot);
0670         if (posSlot >= kStartPosModelIndex)
0671         {
0672           int numDirectBits = ((posSlot >> 1) - 1);
0673 
0674           /* if (bufLimit - buf >= 8) return DUMMY_MATCH; */
0675 
0676           if (posSlot < kEndPosModelIndex)
0677           {
0678             prob = probs + SpecPos + ((2 | (posSlot & 1)) << numDirectBits) - posSlot - 1;
0679           }
0680           else
0681           {
0682             numDirectBits -= kNumAlignBits;
0683             do
0684             {
0685               NORMALIZE_CHECK
0686               range >>= 1;
0687               code -= range & (((code - range) >> 31) - 1);
0688               /* if (code >= range) code -= range; */
0689             }
0690             while (--numDirectBits != 0);
0691             prob = probs + Align;
0692             numDirectBits = kNumAlignBits;
0693           }
0694           {
0695             unsigned i = 1;
0696             do
0697             {
0698               GET_BIT_CHECK(prob + i, i);
0699             }
0700             while (--numDirectBits != 0);
0701           }
0702         }
0703       }
0704     }
0705   }
0706   NORMALIZE_CHECK;
0707   return res;
0708 }
0709 
0710 
0711 static void LzmaDec_InitRc(CLzmaDec *p, const Byte *data)
0712 {
0713   p->code = ((UInt32)data[1] << 24) | ((UInt32)data[2] << 16) | ((UInt32)data[3] << 8) | ((UInt32)data[4]);
0714   p->range = 0xFFFFFFFF;
0715   p->needFlush = 0;
0716 }
0717 
0718 void LzmaDec_InitDicAndState(CLzmaDec *p, Bool initDic, Bool initState)
0719 {
0720   p->needFlush = 1;
0721   p->remainLen = 0;
0722   p->tempBufSize = 0;
0723 
0724   if (initDic)
0725   {
0726     p->processedPos = 0;
0727     p->checkDicSize = 0;
0728     p->needInitState = 1;
0729   }
0730   if (initState)
0731     p->needInitState = 1;
0732 }
0733 
0734 void LzmaDec_Init(CLzmaDec *p)
0735 {
0736   p->dicPos = 0;
0737   LzmaDec_InitDicAndState(p, True, True);
0738 }
0739 
0740 static void LzmaDec_InitStateReal(CLzmaDec *p)
0741 {
0742   UInt32 numProbs = Literal + ((UInt32)LZMA_LIT_SIZE << (p->prop.lc + p->prop.lp));
0743   UInt32 i;
0744   CLzmaProb *probs = p->probs;
0745   for (i = 0; i < numProbs; i++)
0746     probs[i] = kBitModelTotal >> 1;
0747   p->reps[0] = p->reps[1] = p->reps[2] = p->reps[3] = 1;
0748   p->state = 0;
0749   p->needInitState = 0;
0750 }
0751 
0752 SRes LzmaDec_DecodeToDic(CLzmaDec *p, SizeT dicLimit, const Byte *src, SizeT *srcLen,
0753     ELzmaFinishMode finishMode, ELzmaStatus *status)
0754 {
0755   SizeT inSize = *srcLen;
0756   (*srcLen) = 0;
0757   LzmaDec_WriteRem(p, dicLimit);
0758   
0759   *status = LZMA_STATUS_NOT_SPECIFIED;
0760 
0761   while (p->remainLen != kMatchSpecLenStart)
0762   {
0763       int checkEndMarkNow;
0764 
0765       if (p->needFlush != 0)
0766       {
0767         for (; inSize > 0 && p->tempBufSize < RC_INIT_SIZE; (*srcLen)++, inSize--)
0768           p->tempBuf[p->tempBufSize++] = *src++;
0769         if (p->tempBufSize < RC_INIT_SIZE)
0770         {
0771           *status = LZMA_STATUS_NEEDS_MORE_INPUT;
0772           return SZ_OK;
0773         }
0774         if (p->tempBuf[0] != 0)
0775           return SZ_ERROR_DATA;
0776 
0777         LzmaDec_InitRc(p, p->tempBuf);
0778         p->tempBufSize = 0;
0779       }
0780 
0781       checkEndMarkNow = 0;
0782       if (p->dicPos >= dicLimit)
0783       {
0784         if (p->remainLen == 0 && p->code == 0)
0785         {
0786           *status = LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK;
0787           return SZ_OK;
0788         }
0789         if (finishMode == LZMA_FINISH_ANY)
0790         {
0791           *status = LZMA_STATUS_NOT_FINISHED;
0792           return SZ_OK;
0793         }
0794         if (p->remainLen != 0)
0795         {
0796           *status = LZMA_STATUS_NOT_FINISHED;
0797           return SZ_ERROR_DATA;
0798         }
0799         checkEndMarkNow = 1;
0800       }
0801 
0802       if (p->needInitState)
0803         LzmaDec_InitStateReal(p);
0804   
0805       if (p->tempBufSize == 0)
0806       {
0807         SizeT processed;
0808         const Byte *bufLimit;
0809         if (inSize < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow)
0810         {
0811           int dummyRes = LzmaDec_TryDummy(p, src, inSize);
0812           if (dummyRes == DUMMY_ERROR)
0813           {
0814             memcpy(p->tempBuf, src, inSize);
0815             p->tempBufSize = (unsigned)inSize;
0816             (*srcLen) += inSize;
0817             *status = LZMA_STATUS_NEEDS_MORE_INPUT;
0818             return SZ_OK;
0819           }
0820           if (checkEndMarkNow && dummyRes != DUMMY_MATCH)
0821           {
0822             *status = LZMA_STATUS_NOT_FINISHED;
0823             return SZ_ERROR_DATA;
0824           }
0825           bufLimit = src;
0826         }
0827         else
0828           bufLimit = src + inSize - LZMA_REQUIRED_INPUT_MAX;
0829         p->buf = src;
0830         if (LzmaDec_DecodeReal2(p, dicLimit, bufLimit) != 0)
0831           return SZ_ERROR_DATA;
0832         processed = (SizeT)(p->buf - src);
0833         (*srcLen) += processed;
0834         src += processed;
0835         inSize -= processed;
0836       }
0837       else
0838       {
0839         unsigned rem = p->tempBufSize, lookAhead = 0;
0840         while (rem < LZMA_REQUIRED_INPUT_MAX && lookAhead < inSize)
0841           p->tempBuf[rem++] = src[lookAhead++];
0842         p->tempBufSize = rem;
0843         if (rem < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow)
0844         {
0845           int dummyRes = LzmaDec_TryDummy(p, p->tempBuf, rem);
0846           if (dummyRes == DUMMY_ERROR)
0847           {
0848             (*srcLen) += lookAhead;
0849             *status = LZMA_STATUS_NEEDS_MORE_INPUT;
0850             return SZ_OK;
0851           }
0852           if (checkEndMarkNow && dummyRes != DUMMY_MATCH)
0853           {
0854             *status = LZMA_STATUS_NOT_FINISHED;
0855             return SZ_ERROR_DATA;
0856           }
0857         }
0858         p->buf = p->tempBuf;
0859         if (LzmaDec_DecodeReal2(p, dicLimit, p->buf) != 0)
0860           return SZ_ERROR_DATA;
0861         lookAhead -= (rem - (unsigned)(p->buf - p->tempBuf));
0862         (*srcLen) += lookAhead;
0863         src += lookAhead;
0864         inSize -= lookAhead;
0865         p->tempBufSize = 0;
0866       }
0867   }
0868   if (p->code == 0)
0869     *status = LZMA_STATUS_FINISHED_WITH_MARK;
0870   return (p->code == 0) ? SZ_OK : SZ_ERROR_DATA;
0871 }
0872 
0873 SRes LzmaDec_DecodeToBuf(CLzmaDec *p, Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status)
0874 {
0875   SizeT outSize = *destLen;
0876   SizeT inSize = *srcLen;
0877   *srcLen = *destLen = 0;
0878   for (;;)
0879   {
0880     SizeT inSizeCur = inSize, outSizeCur, dicPos;
0881     ELzmaFinishMode curFinishMode;
0882     SRes res;
0883     if (p->dicPos == p->dicBufSize)
0884       p->dicPos = 0;
0885     dicPos = p->dicPos;
0886     if (outSize > p->dicBufSize - dicPos)
0887     {
0888       outSizeCur = p->dicBufSize;
0889       curFinishMode = LZMA_FINISH_ANY;
0890     }
0891     else
0892     {
0893       outSizeCur = dicPos + outSize;
0894       curFinishMode = finishMode;
0895     }
0896 
0897     res = LzmaDec_DecodeToDic(p, outSizeCur, src, &inSizeCur, curFinishMode, status);
0898     src += inSizeCur;
0899     inSize -= inSizeCur;
0900     *srcLen += inSizeCur;
0901     outSizeCur = p->dicPos - dicPos;
0902     memcpy(dest, p->dic + dicPos, outSizeCur);
0903     dest += outSizeCur;
0904     outSize -= outSizeCur;
0905     *destLen += outSizeCur;
0906     if (res != 0)
0907       return res;
0908     if (outSizeCur == 0 || outSize == 0)
0909       return SZ_OK;
0910   }
0911 }
0912 
0913 void LzmaDec_FreeProbs(CLzmaDec *p, ISzAlloc *alloc)
0914 {
0915   alloc->Free(alloc, p->probs);
0916   p->probs = 0;
0917 }
0918 
0919 static void LzmaDec_FreeDict(CLzmaDec *p, ISzAlloc *alloc)
0920 {
0921   alloc->Free(alloc, p->dic);
0922   p->dic = 0;
0923 }
0924 
0925 void LzmaDec_Free(CLzmaDec *p, ISzAlloc *alloc)
0926 {
0927   LzmaDec_FreeProbs(p, alloc);
0928   LzmaDec_FreeDict(p, alloc);
0929 }
0930 
0931 SRes LzmaProps_Decode(CLzmaProps *p, const Byte *data, unsigned size)
0932 {
0933   UInt32 dicSize;
0934   Byte d;
0935   
0936   if (size < LZMA_PROPS_SIZE)
0937     return SZ_ERROR_UNSUPPORTED;
0938   else
0939     dicSize = data[1] | ((UInt32)data[2] << 8) | ((UInt32)data[3] << 16) | ((UInt32)data[4] << 24);
0940  
0941   if (dicSize < LZMA_DIC_MIN)
0942     dicSize = LZMA_DIC_MIN;
0943   p->dicSize = dicSize;
0944 
0945   d = data[0];
0946   if (d >= (9 * 5 * 5))
0947     return SZ_ERROR_UNSUPPORTED;
0948 
0949   p->lc = d % 9;
0950   d /= 9;
0951   p->pb = d / 5;
0952   p->lp = d % 5;
0953 
0954   return SZ_OK;
0955 }
0956 
0957 static SRes LzmaDec_AllocateProbs2(CLzmaDec *p, const CLzmaProps *propNew, ISzAlloc *alloc)
0958 {
0959   UInt32 numProbs = LzmaProps_GetNumProbs(propNew);
0960   if (p->probs == 0 || numProbs != p->numProbs)
0961   {
0962     LzmaDec_FreeProbs(p, alloc);
0963     p->probs = (CLzmaProb *)alloc->Alloc(alloc, numProbs * sizeof(CLzmaProb));
0964     p->numProbs = numProbs;
0965     if (p->probs == 0)
0966       return SZ_ERROR_MEM;
0967   }
0968   return SZ_OK;
0969 }
0970 
0971 SRes LzmaDec_AllocateProbs(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAlloc *alloc)
0972 {
0973   CLzmaProps propNew;
0974   RINOK(LzmaProps_Decode(&propNew, props, propsSize));
0975   RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));
0976   p->prop = propNew;
0977   return SZ_OK;
0978 }
0979 
0980 SRes LzmaDec_Allocate(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAlloc *alloc)
0981 {
0982   CLzmaProps propNew;
0983   SizeT dicBufSize;
0984   RINOK(LzmaProps_Decode(&propNew, props, propsSize));
0985   RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));
0986   dicBufSize = propNew.dicSize;
0987   if (p->dic == 0 || dicBufSize != p->dicBufSize)
0988   {
0989     LzmaDec_FreeDict(p, alloc);
0990     p->dic = (Byte *)alloc->Alloc(alloc, dicBufSize);
0991     if (p->dic == 0)
0992     {
0993       LzmaDec_FreeProbs(p, alloc);
0994       return SZ_ERROR_MEM;
0995     }
0996   }
0997   p->dicBufSize = dicBufSize;
0998   p->prop = propNew;
0999   return SZ_OK;
1000 }
1001 
1002 SRes LzmaDecode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen,
1003     const Byte *propData, unsigned propSize, ELzmaFinishMode finishMode,
1004     ELzmaStatus *status, ISzAlloc *alloc)
1005 {
1006   CLzmaDec p;
1007   SRes res;
1008   SizeT outSize = *destLen, inSize = *srcLen;
1009   *destLen = *srcLen = 0;
1010   *status = LZMA_STATUS_NOT_SPECIFIED;
1011   if (inSize < RC_INIT_SIZE)
1012     return SZ_ERROR_INPUT_EOF;
1013   LzmaDec_Construct(&p);
1014   RINOK(LzmaDec_AllocateProbs(&p, propData, propSize, alloc));
1015   p.dic = dest;
1016   p.dicBufSize = outSize;
1017   LzmaDec_Init(&p);
1018   *srcLen = inSize;
1019   res = LzmaDec_DecodeToDic(&p, outSize, src, srcLen, finishMode, status);
1020   *destLen = p.dicPos;
1021   if (res == SZ_OK && *status == LZMA_STATUS_NEEDS_MORE_INPUT)
1022     res = SZ_ERROR_INPUT_EOF;
1023   LzmaDec_FreeProbs(&p, alloc);
1024   return res;
1025 }