duckstation

duckstation, but archived from the revision just before upstream changed it to a proprietary software project, this version is the libre one
git clone https://git.neptards.moe/u3shit/duckstation.git
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LzmaDec.c (31943B)


      1 /* LzmaDec.c -- LZMA Decoder
      2 2018-07-04 : Igor Pavlov : Public domain */
      3 
      4 #include "Precomp.h"
      5 
      6 #include <string.h>
      7 
      8 /* #include "CpuArch.h" */
      9 #include "LzmaDec.h"
     10 
     11 #define kNumTopBits 24
     12 #define kTopValue ((UInt32)1 << kNumTopBits)
     13 
     14 #define kNumBitModelTotalBits 11
     15 #define kBitModelTotal (1 << kNumBitModelTotalBits)
     16 #define kNumMoveBits 5
     17 
     18 #define RC_INIT_SIZE 5
     19 
     20 #define NORMALIZE if (range < kTopValue) { range <<= 8; code = (code << 8) | (*buf++); }
     21 
     22 #define IF_BIT_0(p) ttt = *(p); NORMALIZE; bound = (range >> kNumBitModelTotalBits) * (UInt32)ttt; if (code < bound)
     23 #define UPDATE_0(p) range = bound; *(p) = (CLzmaProb)(ttt + ((kBitModelTotal - ttt) >> kNumMoveBits));
     24 #define UPDATE_1(p) range -= bound; code -= bound; *(p) = (CLzmaProb)(ttt - (ttt >> kNumMoveBits));
     25 #define GET_BIT2(p, i, A0, A1) IF_BIT_0(p) \
     26   { UPDATE_0(p); i = (i + i); A0; } else \
     27   { UPDATE_1(p); i = (i + i) + 1; A1; }
     28 
     29 #define TREE_GET_BIT(probs, i) { GET_BIT2(probs + i, i, ;, ;); }
     30 
     31 #define REV_BIT(p, i, A0, A1) IF_BIT_0(p + i) \
     32   { UPDATE_0(p + i); A0; } else \
     33   { UPDATE_1(p + i); A1; }
     34 #define REV_BIT_VAR(  p, i, m) REV_BIT(p, i, i += m; m += m, m += m; i += m; )
     35 #define REV_BIT_CONST(p, i, m) REV_BIT(p, i, i += m;       , i += m * 2; )
     36 #define REV_BIT_LAST( p, i, m) REV_BIT(p, i, i -= m        , ; )
     37 
     38 #define TREE_DECODE(probs, limit, i) \
     39   { i = 1; do { TREE_GET_BIT(probs, i); } while (i < limit); i -= limit; }
     40 
     41 /* #define _LZMA_SIZE_OPT */
     42 
     43 #ifdef _LZMA_SIZE_OPT
     44 #define TREE_6_DECODE(probs, i) TREE_DECODE(probs, (1 << 6), i)
     45 #else
     46 #define TREE_6_DECODE(probs, i) \
     47   { i = 1; \
     48   TREE_GET_BIT(probs, i); \
     49   TREE_GET_BIT(probs, i); \
     50   TREE_GET_BIT(probs, i); \
     51   TREE_GET_BIT(probs, i); \
     52   TREE_GET_BIT(probs, i); \
     53   TREE_GET_BIT(probs, i); \
     54   i -= 0x40; }
     55 #endif
     56 
     57 #define NORMAL_LITER_DEC TREE_GET_BIT(prob, symbol)
     58 #define MATCHED_LITER_DEC \
     59   matchByte += matchByte; \
     60   bit = offs; \
     61   offs &= matchByte; \
     62   probLit = prob + (offs + bit + symbol); \
     63   GET_BIT2(probLit, symbol, offs ^= bit; , ;)
     64 
     65 
     66 
     67 #define NORMALIZE_CHECK if (range < kTopValue) { if (buf >= bufLimit) return DUMMY_ERROR; range <<= 8; code = (code << 8) | (*buf++); }
     68 
     69 #define IF_BIT_0_CHECK(p) ttt = *(p); NORMALIZE_CHECK; bound = (range >> kNumBitModelTotalBits) * (UInt32)ttt; if (code < bound)
     70 #define UPDATE_0_CHECK range = bound;
     71 #define UPDATE_1_CHECK range -= bound; code -= bound;
     72 #define GET_BIT2_CHECK(p, i, A0, A1) IF_BIT_0_CHECK(p) \
     73   { UPDATE_0_CHECK; i = (i + i); A0; } else \
     74   { UPDATE_1_CHECK; i = (i + i) + 1; A1; }
     75 #define GET_BIT_CHECK(p, i) GET_BIT2_CHECK(p, i, ; , ;)
     76 #define TREE_DECODE_CHECK(probs, limit, i) \
     77   { i = 1; do { GET_BIT_CHECK(probs + i, i) } while (i < limit); i -= limit; }
     78 
     79 
     80 #define REV_BIT_CHECK(p, i, m) IF_BIT_0_CHECK(p + i) \
     81   { UPDATE_0_CHECK; i += m; m += m; } else \
     82   { UPDATE_1_CHECK; m += m; i += m; }
     83 
     84 
     85 #define kNumPosBitsMax 4
     86 #define kNumPosStatesMax (1 << kNumPosBitsMax)
     87 
     88 #define kLenNumLowBits 3
     89 #define kLenNumLowSymbols (1 << kLenNumLowBits)
     90 #define kLenNumHighBits 8
     91 #define kLenNumHighSymbols (1 << kLenNumHighBits)
     92 
     93 #define LenLow 0
     94 #define LenHigh (LenLow + 2 * (kNumPosStatesMax << kLenNumLowBits))
     95 #define kNumLenProbs (LenHigh + kLenNumHighSymbols)
     96 
     97 #define LenChoice LenLow
     98 #define LenChoice2 (LenLow + (1 << kLenNumLowBits))
     99 
    100 #define kNumStates 12
    101 #define kNumStates2 16
    102 #define kNumLitStates 7
    103 
    104 #define kStartPosModelIndex 4
    105 #define kEndPosModelIndex 14
    106 #define kNumFullDistances (1 << (kEndPosModelIndex >> 1))
    107 
    108 #define kNumPosSlotBits 6
    109 #define kNumLenToPosStates 4
    110 
    111 #define kNumAlignBits 4
    112 #define kAlignTableSize (1 << kNumAlignBits)
    113 
    114 #define kMatchMinLen 2
    115 #define kMatchSpecLenStart (kMatchMinLen + kLenNumLowSymbols * 2 + kLenNumHighSymbols)
    116 
    117 /* External ASM code needs same CLzmaProb array layout. So don't change it. */
    118 
    119 /* (probs_1664) is faster and better for code size at some platforms */
    120 /*
    121 #ifdef MY_CPU_X86_OR_AMD64
    122 */
    123 #define kStartOffset 1664
    124 #define GET_PROBS p->probs_1664
    125 /*
    126 #define GET_PROBS p->probs + kStartOffset
    127 #else
    128 #define kStartOffset 0
    129 #define GET_PROBS p->probs
    130 #endif
    131 */
    132 
    133 #define SpecPos (-kStartOffset)
    134 #define IsRep0Long (SpecPos + kNumFullDistances)
    135 #define RepLenCoder (IsRep0Long + (kNumStates2 << kNumPosBitsMax))
    136 #define LenCoder (RepLenCoder + kNumLenProbs)
    137 #define IsMatch (LenCoder + kNumLenProbs)
    138 #define Align (IsMatch + (kNumStates2 << kNumPosBitsMax))
    139 #define IsRep (Align + kAlignTableSize)
    140 #define IsRepG0 (IsRep + kNumStates)
    141 #define IsRepG1 (IsRepG0 + kNumStates)
    142 #define IsRepG2 (IsRepG1 + kNumStates)
    143 #define PosSlot (IsRepG2 + kNumStates)
    144 #define Literal (PosSlot + (kNumLenToPosStates << kNumPosSlotBits))
    145 #define NUM_BASE_PROBS (Literal + kStartOffset)
    146 
    147 #if Align != 0 && kStartOffset != 0
    148   #error Stop_Compiling_Bad_LZMA_kAlign
    149 #endif
    150 
    151 #if NUM_BASE_PROBS != 1984
    152   #error Stop_Compiling_Bad_LZMA_PROBS
    153 #endif
    154 
    155 
    156 #define LZMA_LIT_SIZE 0x300
    157 
    158 #define LzmaProps_GetNumProbs(p) (NUM_BASE_PROBS + ((UInt32)LZMA_LIT_SIZE << ((p)->lc + (p)->lp)))
    159 
    160 
    161 #define CALC_POS_STATE(processedPos, pbMask) (((processedPos) & (pbMask)) << 4)
    162 #define COMBINED_PS_STATE (posState + state)
    163 #define GET_LEN_STATE (posState)
    164 
    165 #define LZMA_DIC_MIN (1 << 12)
    166 
    167 /*
    168 p->remainLen : shows status of LZMA decoder:
    169     < kMatchSpecLenStart : normal remain
    170     = kMatchSpecLenStart : finished
    171     = kMatchSpecLenStart + 1 : need init range coder
    172     = kMatchSpecLenStart + 2 : need init range coder and state
    173 */
    174 
    175 /* ---------- LZMA_DECODE_REAL ---------- */
    176 /*
    177 LzmaDec_DecodeReal_3() can be implemented in external ASM file.
    178 3 - is the code compatibility version of that function for check at link time.
    179 */
    180 
    181 #define LZMA_DECODE_REAL LzmaDec_DecodeReal_3
    182 
    183 /*
    184 LZMA_DECODE_REAL()
    185 In:
    186   RangeCoder is normalized
    187   if (p->dicPos == limit)
    188   {
    189     LzmaDec_TryDummy() was called before to exclude LITERAL and MATCH-REP cases.
    190     So first symbol can be only MATCH-NON-REP. And if that MATCH-NON-REP symbol
    191     is not END_OF_PAYALOAD_MARKER, then function returns error code.
    192   }
    193 
    194 Processing:
    195   first LZMA symbol will be decoded in any case
    196   All checks for limits are at the end of main loop,
    197   It will decode new LZMA-symbols while (p->buf < bufLimit && dicPos < limit),
    198   RangeCoder is still without last normalization when (p->buf < bufLimit) is being checked.
    199 
    200 Out:
    201   RangeCoder is normalized
    202   Result:
    203     SZ_OK - OK
    204     SZ_ERROR_DATA - Error
    205   p->remainLen:
    206     < kMatchSpecLenStart : normal remain
    207     = kMatchSpecLenStart : finished
    208 */
    209 
    210 
    211 #ifdef _LZMA_DEC_OPT
    212 
    213 int MY_FAST_CALL LZMA_DECODE_REAL(CLzmaDec *p, SizeT limit, const Byte *bufLimit);
    214 
    215 #else
    216 
    217 static
    218 int MY_FAST_CALL LZMA_DECODE_REAL(CLzmaDec *p, SizeT limit, const Byte *bufLimit)
    219 {
    220   CLzmaProb *probs = GET_PROBS;
    221   unsigned state = (unsigned)p->state;
    222   UInt32 rep0 = p->reps[0], rep1 = p->reps[1], rep2 = p->reps[2], rep3 = p->reps[3];
    223   unsigned pbMask = ((unsigned)1 << (p->prop.pb)) - 1;
    224   unsigned lc = p->prop.lc;
    225   unsigned lpMask = ((unsigned)0x100 << p->prop.lp) - ((unsigned)0x100 >> lc);
    226 
    227   Byte *dic = p->dic;
    228   SizeT dicBufSize = p->dicBufSize;
    229   SizeT dicPos = p->dicPos;
    230   
    231   UInt32 processedPos = p->processedPos;
    232   UInt32 checkDicSize = p->checkDicSize;
    233   unsigned len = 0;
    234 
    235   const Byte *buf = p->buf;
    236   UInt32 range = p->range;
    237   UInt32 code = p->code;
    238 
    239   do
    240   {
    241     CLzmaProb *prob;
    242     UInt32 bound;
    243     unsigned ttt;
    244     unsigned posState = CALC_POS_STATE(processedPos, pbMask);
    245 
    246     prob = probs + IsMatch + COMBINED_PS_STATE;
    247     IF_BIT_0(prob)
    248     {
    249       unsigned symbol;
    250       UPDATE_0(prob);
    251       prob = probs + Literal;
    252       if (processedPos != 0 || checkDicSize != 0)
    253         prob += (UInt32)3 * ((((processedPos << 8) + dic[(dicPos == 0 ? dicBufSize : dicPos) - 1]) & lpMask) << lc);
    254       processedPos++;
    255 
    256       if (state < kNumLitStates)
    257       {
    258         state -= (state < 4) ? state : 3;
    259         symbol = 1;
    260         #ifdef _LZMA_SIZE_OPT
    261         do { NORMAL_LITER_DEC } while (symbol < 0x100);
    262         #else
    263         NORMAL_LITER_DEC
    264         NORMAL_LITER_DEC
    265         NORMAL_LITER_DEC
    266         NORMAL_LITER_DEC
    267         NORMAL_LITER_DEC
    268         NORMAL_LITER_DEC
    269         NORMAL_LITER_DEC
    270         NORMAL_LITER_DEC
    271         #endif
    272       }
    273       else
    274       {
    275         unsigned matchByte = dic[dicPos - rep0 + (dicPos < rep0 ? dicBufSize : 0)];
    276         unsigned offs = 0x100;
    277         state -= (state < 10) ? 3 : 6;
    278         symbol = 1;
    279         #ifdef _LZMA_SIZE_OPT
    280         do
    281         {
    282           unsigned bit;
    283           CLzmaProb *probLit;
    284           MATCHED_LITER_DEC
    285         }
    286         while (symbol < 0x100);
    287         #else
    288         {
    289           unsigned bit;
    290           CLzmaProb *probLit;
    291           MATCHED_LITER_DEC
    292           MATCHED_LITER_DEC
    293           MATCHED_LITER_DEC
    294           MATCHED_LITER_DEC
    295           MATCHED_LITER_DEC
    296           MATCHED_LITER_DEC
    297           MATCHED_LITER_DEC
    298           MATCHED_LITER_DEC
    299         }
    300         #endif
    301       }
    302 
    303       dic[dicPos++] = (Byte)symbol;
    304       continue;
    305     }
    306     
    307     {
    308       UPDATE_1(prob);
    309       prob = probs + IsRep + state;
    310       IF_BIT_0(prob)
    311       {
    312         UPDATE_0(prob);
    313         state += kNumStates;
    314         prob = probs + LenCoder;
    315       }
    316       else
    317       {
    318         UPDATE_1(prob);
    319         /*
    320         // that case was checked before with kBadRepCode
    321         if (checkDicSize == 0 && processedPos == 0)
    322           return SZ_ERROR_DATA;
    323         */
    324         prob = probs + IsRepG0 + state;
    325         IF_BIT_0(prob)
    326         {
    327           UPDATE_0(prob);
    328           prob = probs + IsRep0Long + COMBINED_PS_STATE;
    329           IF_BIT_0(prob)
    330           {
    331             UPDATE_0(prob);
    332             dic[dicPos] = dic[dicPos - rep0 + (dicPos < rep0 ? dicBufSize : 0)];
    333             dicPos++;
    334             processedPos++;
    335             state = state < kNumLitStates ? 9 : 11;
    336             continue;
    337           }
    338           UPDATE_1(prob);
    339         }
    340         else
    341         {
    342           UInt32 distance;
    343           UPDATE_1(prob);
    344           prob = probs + IsRepG1 + state;
    345           IF_BIT_0(prob)
    346           {
    347             UPDATE_0(prob);
    348             distance = rep1;
    349           }
    350           else
    351           {
    352             UPDATE_1(prob);
    353             prob = probs + IsRepG2 + state;
    354             IF_BIT_0(prob)
    355             {
    356               UPDATE_0(prob);
    357               distance = rep2;
    358             }
    359             else
    360             {
    361               UPDATE_1(prob);
    362               distance = rep3;
    363               rep3 = rep2;
    364             }
    365             rep2 = rep1;
    366           }
    367           rep1 = rep0;
    368           rep0 = distance;
    369         }
    370         state = state < kNumLitStates ? 8 : 11;
    371         prob = probs + RepLenCoder;
    372       }
    373       
    374       #ifdef _LZMA_SIZE_OPT
    375       {
    376         unsigned lim, offset;
    377         CLzmaProb *probLen = prob + LenChoice;
    378         IF_BIT_0(probLen)
    379         {
    380           UPDATE_0(probLen);
    381           probLen = prob + LenLow + GET_LEN_STATE;
    382           offset = 0;
    383           lim = (1 << kLenNumLowBits);
    384         }
    385         else
    386         {
    387           UPDATE_1(probLen);
    388           probLen = prob + LenChoice2;
    389           IF_BIT_0(probLen)
    390           {
    391             UPDATE_0(probLen);
    392             probLen = prob + LenLow + GET_LEN_STATE + (1 << kLenNumLowBits);
    393             offset = kLenNumLowSymbols;
    394             lim = (1 << kLenNumLowBits);
    395           }
    396           else
    397           {
    398             UPDATE_1(probLen);
    399             probLen = prob + LenHigh;
    400             offset = kLenNumLowSymbols * 2;
    401             lim = (1 << kLenNumHighBits);
    402           }
    403         }
    404         TREE_DECODE(probLen, lim, len);
    405         len += offset;
    406       }
    407       #else
    408       {
    409         CLzmaProb *probLen = prob + LenChoice;
    410         IF_BIT_0(probLen)
    411         {
    412           UPDATE_0(probLen);
    413           probLen = prob + LenLow + GET_LEN_STATE;
    414           len = 1;
    415           TREE_GET_BIT(probLen, len);
    416           TREE_GET_BIT(probLen, len);
    417           TREE_GET_BIT(probLen, len);
    418           len -= 8;
    419         }
    420         else
    421         {
    422           UPDATE_1(probLen);
    423           probLen = prob + LenChoice2;
    424           IF_BIT_0(probLen)
    425           {
    426             UPDATE_0(probLen);
    427             probLen = prob + LenLow + GET_LEN_STATE + (1 << kLenNumLowBits);
    428             len = 1;
    429             TREE_GET_BIT(probLen, len);
    430             TREE_GET_BIT(probLen, len);
    431             TREE_GET_BIT(probLen, len);
    432           }
    433           else
    434           {
    435             UPDATE_1(probLen);
    436             probLen = prob + LenHigh;
    437             TREE_DECODE(probLen, (1 << kLenNumHighBits), len);
    438             len += kLenNumLowSymbols * 2;
    439           }
    440         }
    441       }
    442       #endif
    443 
    444       if (state >= kNumStates)
    445       {
    446         UInt32 distance;
    447         prob = probs + PosSlot +
    448             ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) << kNumPosSlotBits);
    449         TREE_6_DECODE(prob, distance);
    450         if (distance >= kStartPosModelIndex)
    451         {
    452           unsigned posSlot = (unsigned)distance;
    453           unsigned numDirectBits = (unsigned)(((distance >> 1) - 1));
    454           distance = (2 | (distance & 1));
    455           if (posSlot < kEndPosModelIndex)
    456           {
    457             distance <<= numDirectBits;
    458             prob = probs + SpecPos;
    459             {
    460               UInt32 m = 1;
    461               distance++;
    462               do
    463               {
    464                 REV_BIT_VAR(prob, distance, m);
    465               }
    466               while (--numDirectBits);
    467               distance -= m;
    468             }
    469           }
    470           else
    471           {
    472             numDirectBits -= kNumAlignBits;
    473             do
    474             {
    475               NORMALIZE
    476               range >>= 1;
    477               
    478               {
    479                 UInt32 t;
    480                 code -= range;
    481                 t = (0 - ((UInt32)code >> 31)); /* (UInt32)((Int32)code >> 31) */
    482                 distance = (distance << 1) + (t + 1);
    483                 code += range & t;
    484               }
    485               /*
    486               distance <<= 1;
    487               if (code >= range)
    488               {
    489                 code -= range;
    490                 distance |= 1;
    491               }
    492               */
    493             }
    494             while (--numDirectBits);
    495             prob = probs + Align;
    496             distance <<= kNumAlignBits;
    497             {
    498               unsigned i = 1;
    499               REV_BIT_CONST(prob, i, 1);
    500               REV_BIT_CONST(prob, i, 2);
    501               REV_BIT_CONST(prob, i, 4);
    502               REV_BIT_LAST (prob, i, 8);
    503               distance |= i;
    504             }
    505             if (distance == (UInt32)0xFFFFFFFF)
    506             {
    507               len = kMatchSpecLenStart;
    508               state -= kNumStates;
    509               break;
    510             }
    511           }
    512         }
    513         
    514         rep3 = rep2;
    515         rep2 = rep1;
    516         rep1 = rep0;
    517         rep0 = distance + 1;
    518         state = (state < kNumStates + kNumLitStates) ? kNumLitStates : kNumLitStates + 3;
    519         if (distance >= (checkDicSize == 0 ? processedPos: checkDicSize))
    520         {
    521           p->dicPos = dicPos;
    522           return SZ_ERROR_DATA;
    523         }
    524       }
    525 
    526       len += kMatchMinLen;
    527 
    528       {
    529         SizeT rem;
    530         unsigned curLen;
    531         SizeT pos;
    532         
    533         if ((rem = limit - dicPos) == 0)
    534         {
    535           p->dicPos = dicPos;
    536           return SZ_ERROR_DATA;
    537         }
    538         
    539         curLen = ((rem < len) ? (unsigned)rem : len);
    540         pos = dicPos - rep0 + (dicPos < rep0 ? dicBufSize : 0);
    541 
    542         processedPos += (UInt32)curLen;
    543 
    544         len -= curLen;
    545         if (curLen <= dicBufSize - pos)
    546         {
    547           Byte *dest = dic + dicPos;
    548           ptrdiff_t src = (ptrdiff_t)pos - (ptrdiff_t)dicPos;
    549           const Byte *lim = dest + curLen;
    550           dicPos += (SizeT)curLen;
    551           do
    552             *(dest) = (Byte)*(dest + src);
    553           while (++dest != lim);
    554         }
    555         else
    556         {
    557           do
    558           {
    559             dic[dicPos++] = dic[pos];
    560             if (++pos == dicBufSize)
    561               pos = 0;
    562           }
    563           while (--curLen != 0);
    564         }
    565       }
    566     }
    567   }
    568   while (dicPos < limit && buf < bufLimit);
    569 
    570   NORMALIZE;
    571   
    572   p->buf = buf;
    573   p->range = range;
    574   p->code = code;
    575   p->remainLen = (UInt32)len;
    576   p->dicPos = dicPos;
    577   p->processedPos = processedPos;
    578   p->reps[0] = rep0;
    579   p->reps[1] = rep1;
    580   p->reps[2] = rep2;
    581   p->reps[3] = rep3;
    582   p->state = (UInt32)state;
    583 
    584   return SZ_OK;
    585 }
    586 #endif
    587 
    588 static void MY_FAST_CALL LzmaDec_WriteRem(CLzmaDec *p, SizeT limit)
    589 {
    590   if (p->remainLen != 0 && p->remainLen < kMatchSpecLenStart)
    591   {
    592     Byte *dic = p->dic;
    593     SizeT dicPos = p->dicPos;
    594     SizeT dicBufSize = p->dicBufSize;
    595     unsigned len = (unsigned)p->remainLen;
    596     SizeT rep0 = p->reps[0]; /* we use SizeT to avoid the BUG of VC14 for AMD64 */
    597     SizeT rem = limit - dicPos;
    598     if (rem < len)
    599       len = (unsigned)(rem);
    600 
    601     if (p->checkDicSize == 0 && p->prop.dicSize - p->processedPos <= len)
    602       p->checkDicSize = p->prop.dicSize;
    603 
    604     p->processedPos += (UInt32)len;
    605     p->remainLen -= (UInt32)len;
    606     while (len != 0)
    607     {
    608       len--;
    609       dic[dicPos] = dic[dicPos - rep0 + (dicPos < rep0 ? dicBufSize : 0)];
    610       dicPos++;
    611     }
    612     p->dicPos = dicPos;
    613   }
    614 }
    615 
    616 
    617 #define kRange0 0xFFFFFFFF
    618 #define kBound0 ((kRange0 >> kNumBitModelTotalBits) << (kNumBitModelTotalBits - 1))
    619 #define kBadRepCode (kBound0 + (((kRange0 - kBound0) >> kNumBitModelTotalBits) << (kNumBitModelTotalBits - 1)))
    620 #if kBadRepCode != (0xC0000000 - 0x400)
    621   #error Stop_Compiling_Bad_LZMA_Check
    622 #endif
    623 
    624 static int MY_FAST_CALL LzmaDec_DecodeReal2(CLzmaDec *p, SizeT limit, const Byte *bufLimit)
    625 {
    626   do
    627   {
    628     SizeT limit2 = limit;
    629     if (p->checkDicSize == 0)
    630     {
    631       UInt32 rem = p->prop.dicSize - p->processedPos;
    632       if (limit - p->dicPos > rem)
    633         limit2 = p->dicPos + rem;
    634 
    635       if (p->processedPos == 0)
    636         if (p->code >= kBadRepCode)
    637           return SZ_ERROR_DATA;
    638     }
    639 
    640     RINOK(LZMA_DECODE_REAL(p, limit2, bufLimit));
    641     
    642     if (p->checkDicSize == 0 && p->processedPos >= p->prop.dicSize)
    643       p->checkDicSize = p->prop.dicSize;
    644     
    645     LzmaDec_WriteRem(p, limit);
    646   }
    647   while (p->dicPos < limit && p->buf < bufLimit && p->remainLen < kMatchSpecLenStart);
    648 
    649   return 0;
    650 }
    651 
    652 typedef enum
    653 {
    654   DUMMY_ERROR, /* unexpected end of input stream */
    655   DUMMY_LIT,
    656   DUMMY_MATCH,
    657   DUMMY_REP
    658 } ELzmaDummy;
    659 
    660 static ELzmaDummy LzmaDec_TryDummy(const CLzmaDec *p, const Byte *buf, SizeT inSize)
    661 {
    662   UInt32 range = p->range;
    663   UInt32 code = p->code;
    664   const Byte *bufLimit = buf + inSize;
    665   const CLzmaProb *probs = GET_PROBS;
    666   unsigned state = (unsigned)p->state;
    667   ELzmaDummy res;
    668 
    669   {
    670     const CLzmaProb *prob;
    671     UInt32 bound;
    672     unsigned ttt;
    673     unsigned posState = CALC_POS_STATE(p->processedPos, (1 << p->prop.pb) - 1);
    674 
    675     prob = probs + IsMatch + COMBINED_PS_STATE;
    676     IF_BIT_0_CHECK(prob)
    677     {
    678       UPDATE_0_CHECK
    679 
    680       /* if (bufLimit - buf >= 7) return DUMMY_LIT; */
    681 
    682       prob = probs + Literal;
    683       if (p->checkDicSize != 0 || p->processedPos != 0)
    684         prob += ((UInt32)LZMA_LIT_SIZE *
    685             ((((p->processedPos) & ((1 << (p->prop.lp)) - 1)) << p->prop.lc) +
    686             (p->dic[(p->dicPos == 0 ? p->dicBufSize : p->dicPos) - 1] >> (8 - p->prop.lc))));
    687 
    688       if (state < kNumLitStates)
    689       {
    690         unsigned symbol = 1;
    691         do { GET_BIT_CHECK(prob + symbol, symbol) } while (symbol < 0x100);
    692       }
    693       else
    694       {
    695         unsigned matchByte = p->dic[p->dicPos - p->reps[0] +
    696             (p->dicPos < p->reps[0] ? p->dicBufSize : 0)];
    697         unsigned offs = 0x100;
    698         unsigned symbol = 1;
    699         do
    700         {
    701           unsigned bit;
    702           const CLzmaProb *probLit;
    703           matchByte += matchByte;
    704           bit = offs;
    705           offs &= matchByte;
    706           probLit = prob + (offs + bit + symbol);
    707           GET_BIT2_CHECK(probLit, symbol, offs ^= bit; , ; )
    708         }
    709         while (symbol < 0x100);
    710       }
    711       res = DUMMY_LIT;
    712     }
    713     else
    714     {
    715       unsigned len;
    716       UPDATE_1_CHECK;
    717 
    718       prob = probs + IsRep + state;
    719       IF_BIT_0_CHECK(prob)
    720       {
    721         UPDATE_0_CHECK;
    722         state = 0;
    723         prob = probs + LenCoder;
    724         res = DUMMY_MATCH;
    725       }
    726       else
    727       {
    728         UPDATE_1_CHECK;
    729         res = DUMMY_REP;
    730         prob = probs + IsRepG0 + state;
    731         IF_BIT_0_CHECK(prob)
    732         {
    733           UPDATE_0_CHECK;
    734           prob = probs + IsRep0Long + COMBINED_PS_STATE;
    735           IF_BIT_0_CHECK(prob)
    736           {
    737             UPDATE_0_CHECK;
    738             NORMALIZE_CHECK;
    739             return DUMMY_REP;
    740           }
    741           else
    742           {
    743             UPDATE_1_CHECK;
    744           }
    745         }
    746         else
    747         {
    748           UPDATE_1_CHECK;
    749           prob = probs + IsRepG1 + state;
    750           IF_BIT_0_CHECK(prob)
    751           {
    752             UPDATE_0_CHECK;
    753           }
    754           else
    755           {
    756             UPDATE_1_CHECK;
    757             prob = probs + IsRepG2 + state;
    758             IF_BIT_0_CHECK(prob)
    759             {
    760               UPDATE_0_CHECK;
    761             }
    762             else
    763             {
    764               UPDATE_1_CHECK;
    765             }
    766           }
    767         }
    768         state = kNumStates;
    769         prob = probs + RepLenCoder;
    770       }
    771       {
    772         unsigned limit, offset;
    773         const CLzmaProb *probLen = prob + LenChoice;
    774         IF_BIT_0_CHECK(probLen)
    775         {
    776           UPDATE_0_CHECK;
    777           probLen = prob + LenLow + GET_LEN_STATE;
    778           offset = 0;
    779           limit = 1 << kLenNumLowBits;
    780         }
    781         else
    782         {
    783           UPDATE_1_CHECK;
    784           probLen = prob + LenChoice2;
    785           IF_BIT_0_CHECK(probLen)
    786           {
    787             UPDATE_0_CHECK;
    788             probLen = prob + LenLow + GET_LEN_STATE + (1 << kLenNumLowBits);
    789             offset = kLenNumLowSymbols;
    790             limit = 1 << kLenNumLowBits;
    791           }
    792           else
    793           {
    794             UPDATE_1_CHECK;
    795             probLen = prob + LenHigh;
    796             offset = kLenNumLowSymbols * 2;
    797             limit = 1 << kLenNumHighBits;
    798           }
    799         }
    800         TREE_DECODE_CHECK(probLen, limit, len);
    801         len += offset;
    802       }
    803 
    804       if (state < 4)
    805       {
    806         unsigned posSlot;
    807         prob = probs + PosSlot +
    808             ((len < kNumLenToPosStates - 1 ? len : kNumLenToPosStates - 1) <<
    809             kNumPosSlotBits);
    810         TREE_DECODE_CHECK(prob, 1 << kNumPosSlotBits, posSlot);
    811         if (posSlot >= kStartPosModelIndex)
    812         {
    813           unsigned numDirectBits = ((posSlot >> 1) - 1);
    814 
    815           /* if (bufLimit - buf >= 8) return DUMMY_MATCH; */
    816 
    817           if (posSlot < kEndPosModelIndex)
    818           {
    819             prob = probs + SpecPos + ((2 | (posSlot & 1)) << numDirectBits);
    820           }
    821           else
    822           {
    823             numDirectBits -= kNumAlignBits;
    824             do
    825             {
    826               NORMALIZE_CHECK
    827               range >>= 1;
    828               code -= range & (((code - range) >> 31) - 1);
    829               /* if (code >= range) code -= range; */
    830             }
    831             while (--numDirectBits);
    832             prob = probs + Align;
    833             numDirectBits = kNumAlignBits;
    834           }
    835           {
    836             unsigned i = 1;
    837             unsigned m = 1;
    838             do
    839             {
    840               REV_BIT_CHECK(prob, i, m);
    841             }
    842             while (--numDirectBits);
    843           }
    844         }
    845       }
    846     }
    847   }
    848   NORMALIZE_CHECK;
    849   return res;
    850 }
    851 
    852 
    853 void LzmaDec_InitDicAndState(CLzmaDec *p, BoolInt initDic, BoolInt initState)
    854 {
    855   p->remainLen = kMatchSpecLenStart + 1;
    856   p->tempBufSize = 0;
    857 
    858   if (initDic)
    859   {
    860     p->processedPos = 0;
    861     p->checkDicSize = 0;
    862     p->remainLen = kMatchSpecLenStart + 2;
    863   }
    864   if (initState)
    865     p->remainLen = kMatchSpecLenStart + 2;
    866 }
    867 
    868 void LzmaDec_Init(CLzmaDec *p)
    869 {
    870   p->dicPos = 0;
    871   LzmaDec_InitDicAndState(p, True, True);
    872 }
    873 
    874 
    875 SRes LzmaDec_DecodeToDic(CLzmaDec *p, SizeT dicLimit, const Byte *src, SizeT *srcLen,
    876     ELzmaFinishMode finishMode, ELzmaStatus *status)
    877 {
    878   SizeT inSize = *srcLen;
    879   (*srcLen) = 0;
    880   
    881   *status = LZMA_STATUS_NOT_SPECIFIED;
    882 
    883   if (p->remainLen > kMatchSpecLenStart)
    884   {
    885     for (; inSize > 0 && p->tempBufSize < RC_INIT_SIZE; (*srcLen)++, inSize--)
    886       p->tempBuf[p->tempBufSize++] = *src++;
    887     if (p->tempBufSize != 0 && p->tempBuf[0] != 0)
    888       return SZ_ERROR_DATA;
    889     if (p->tempBufSize < RC_INIT_SIZE)
    890     {
    891       *status = LZMA_STATUS_NEEDS_MORE_INPUT;
    892       return SZ_OK;
    893     }
    894     p->code =
    895         ((UInt32)p->tempBuf[1] << 24)
    896       | ((UInt32)p->tempBuf[2] << 16)
    897       | ((UInt32)p->tempBuf[3] << 8)
    898       | ((UInt32)p->tempBuf[4]);
    899     p->range = 0xFFFFFFFF;
    900     p->tempBufSize = 0;
    901 
    902     if (p->remainLen > kMatchSpecLenStart + 1)
    903     {
    904       SizeT numProbs = LzmaProps_GetNumProbs(&p->prop);
    905       SizeT i;
    906       CLzmaProb *probs = p->probs;
    907       for (i = 0; i < numProbs; i++)
    908         probs[i] = kBitModelTotal >> 1;
    909       p->reps[0] = p->reps[1] = p->reps[2] = p->reps[3] = 1;
    910       p->state = 0;
    911     }
    912 
    913     p->remainLen = 0;
    914   }
    915 
    916   LzmaDec_WriteRem(p, dicLimit);
    917 
    918   while (p->remainLen != kMatchSpecLenStart)
    919   {
    920       int checkEndMarkNow = 0;
    921 
    922       if (p->dicPos >= dicLimit)
    923       {
    924         if (p->remainLen == 0 && p->code == 0)
    925         {
    926           *status = LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK;
    927           return SZ_OK;
    928         }
    929         if (finishMode == LZMA_FINISH_ANY)
    930         {
    931           *status = LZMA_STATUS_NOT_FINISHED;
    932           return SZ_OK;
    933         }
    934         if (p->remainLen != 0)
    935         {
    936           *status = LZMA_STATUS_NOT_FINISHED;
    937           return SZ_ERROR_DATA;
    938         }
    939         checkEndMarkNow = 1;
    940       }
    941 
    942       if (p->tempBufSize == 0)
    943       {
    944         SizeT processed;
    945         const Byte *bufLimit;
    946         if (inSize < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow)
    947         {
    948           int dummyRes = LzmaDec_TryDummy(p, src, inSize);
    949           if (dummyRes == DUMMY_ERROR)
    950           {
    951             memcpy(p->tempBuf, src, inSize);
    952             p->tempBufSize = (unsigned)inSize;
    953             (*srcLen) += inSize;
    954             *status = LZMA_STATUS_NEEDS_MORE_INPUT;
    955             return SZ_OK;
    956           }
    957           if (checkEndMarkNow && dummyRes != DUMMY_MATCH)
    958           {
    959             *status = LZMA_STATUS_NOT_FINISHED;
    960             return SZ_ERROR_DATA;
    961           }
    962           bufLimit = src;
    963         }
    964         else
    965           bufLimit = src + inSize - LZMA_REQUIRED_INPUT_MAX;
    966         p->buf = src;
    967         if (LzmaDec_DecodeReal2(p, dicLimit, bufLimit) != 0)
    968           return SZ_ERROR_DATA;
    969         processed = (SizeT)(p->buf - src);
    970         (*srcLen) += processed;
    971         src += processed;
    972         inSize -= processed;
    973       }
    974       else
    975       {
    976         unsigned rem = p->tempBufSize, lookAhead = 0;
    977         while (rem < LZMA_REQUIRED_INPUT_MAX && lookAhead < inSize)
    978           p->tempBuf[rem++] = src[lookAhead++];
    979         p->tempBufSize = rem;
    980         if (rem < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow)
    981         {
    982           int dummyRes = LzmaDec_TryDummy(p, p->tempBuf, (SizeT)rem);
    983           if (dummyRes == DUMMY_ERROR)
    984           {
    985             (*srcLen) += (SizeT)lookAhead;
    986             *status = LZMA_STATUS_NEEDS_MORE_INPUT;
    987             return SZ_OK;
    988           }
    989           if (checkEndMarkNow && dummyRes != DUMMY_MATCH)
    990           {
    991             *status = LZMA_STATUS_NOT_FINISHED;
    992             return SZ_ERROR_DATA;
    993           }
    994         }
    995         p->buf = p->tempBuf;
    996         if (LzmaDec_DecodeReal2(p, dicLimit, p->buf) != 0)
    997           return SZ_ERROR_DATA;
    998         
    999         {
   1000           unsigned kkk = (unsigned)(p->buf - p->tempBuf);
   1001           if (rem < kkk)
   1002             return SZ_ERROR_FAIL; /* some internal error */
   1003           rem -= kkk;
   1004           if (lookAhead < rem)
   1005             return SZ_ERROR_FAIL; /* some internal error */
   1006           lookAhead -= rem;
   1007         }
   1008         (*srcLen) += (SizeT)lookAhead;
   1009         src += lookAhead;
   1010         inSize -= (SizeT)lookAhead;
   1011         p->tempBufSize = 0;
   1012       }
   1013   }
   1014   
   1015   if (p->code != 0)
   1016     return SZ_ERROR_DATA;
   1017   *status = LZMA_STATUS_FINISHED_WITH_MARK;
   1018   return SZ_OK;
   1019 }
   1020 
   1021 
   1022 SRes LzmaDec_DecodeToBuf(CLzmaDec *p, Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status)
   1023 {
   1024   SizeT outSize = *destLen;
   1025   SizeT inSize = *srcLen;
   1026   *srcLen = *destLen = 0;
   1027   for (;;)
   1028   {
   1029     SizeT inSizeCur = inSize, outSizeCur, dicPos;
   1030     ELzmaFinishMode curFinishMode;
   1031     SRes res;
   1032     if (p->dicPos == p->dicBufSize)
   1033       p->dicPos = 0;
   1034     dicPos = p->dicPos;
   1035     if (outSize > p->dicBufSize - dicPos)
   1036     {
   1037       outSizeCur = p->dicBufSize;
   1038       curFinishMode = LZMA_FINISH_ANY;
   1039     }
   1040     else
   1041     {
   1042       outSizeCur = dicPos + outSize;
   1043       curFinishMode = finishMode;
   1044     }
   1045 
   1046     res = LzmaDec_DecodeToDic(p, outSizeCur, src, &inSizeCur, curFinishMode, status);
   1047     src += inSizeCur;
   1048     inSize -= inSizeCur;
   1049     *srcLen += inSizeCur;
   1050     outSizeCur = p->dicPos - dicPos;
   1051     memcpy(dest, p->dic + dicPos, outSizeCur);
   1052     dest += outSizeCur;
   1053     outSize -= outSizeCur;
   1054     *destLen += outSizeCur;
   1055     if (res != 0)
   1056       return res;
   1057     if (outSizeCur == 0 || outSize == 0)
   1058       return SZ_OK;
   1059   }
   1060 }
   1061 
   1062 void LzmaDec_FreeProbs(CLzmaDec *p, ISzAllocPtr alloc)
   1063 {
   1064   ISzAlloc_Free(alloc, p->probs);
   1065   p->probs = NULL;
   1066 }
   1067 
   1068 static void LzmaDec_FreeDict(CLzmaDec *p, ISzAllocPtr alloc)
   1069 {
   1070   ISzAlloc_Free(alloc, p->dic);
   1071   p->dic = NULL;
   1072 }
   1073 
   1074 void LzmaDec_Free(CLzmaDec *p, ISzAllocPtr alloc)
   1075 {
   1076   LzmaDec_FreeProbs(p, alloc);
   1077   LzmaDec_FreeDict(p, alloc);
   1078 }
   1079 
   1080 SRes LzmaProps_Decode(CLzmaProps *p, const Byte *data, unsigned size)
   1081 {
   1082   UInt32 dicSize;
   1083   Byte d;
   1084   
   1085   if (size < LZMA_PROPS_SIZE)
   1086     return SZ_ERROR_UNSUPPORTED;
   1087   else
   1088     dicSize = data[1] | ((UInt32)data[2] << 8) | ((UInt32)data[3] << 16) | ((UInt32)data[4] << 24);
   1089  
   1090   if (dicSize < LZMA_DIC_MIN)
   1091     dicSize = LZMA_DIC_MIN;
   1092   p->dicSize = dicSize;
   1093 
   1094   d = data[0];
   1095   if (d >= (9 * 5 * 5))
   1096     return SZ_ERROR_UNSUPPORTED;
   1097 
   1098   p->lc = (Byte)(d % 9);
   1099   d /= 9;
   1100   p->pb = (Byte)(d / 5);
   1101   p->lp = (Byte)(d % 5);
   1102 
   1103   return SZ_OK;
   1104 }
   1105 
   1106 static SRes LzmaDec_AllocateProbs2(CLzmaDec *p, const CLzmaProps *propNew, ISzAllocPtr alloc)
   1107 {
   1108   UInt32 numProbs = LzmaProps_GetNumProbs(propNew);
   1109   if (!p->probs || numProbs != p->numProbs)
   1110   {
   1111     LzmaDec_FreeProbs(p, alloc);
   1112     p->probs = (CLzmaProb *)ISzAlloc_Alloc(alloc, numProbs * sizeof(CLzmaProb));
   1113     if (!p->probs)
   1114       return SZ_ERROR_MEM;
   1115     p->probs_1664 = p->probs + 1664;
   1116     p->numProbs = numProbs;
   1117   }
   1118   return SZ_OK;
   1119 }
   1120 
   1121 SRes LzmaDec_AllocateProbs(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAllocPtr alloc)
   1122 {
   1123   CLzmaProps propNew;
   1124   RINOK(LzmaProps_Decode(&propNew, props, propsSize));
   1125   RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));
   1126   p->prop = propNew;
   1127   return SZ_OK;
   1128 }
   1129 
   1130 SRes LzmaDec_Allocate(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAllocPtr alloc)
   1131 {
   1132   CLzmaProps propNew;
   1133   SizeT dicBufSize;
   1134   RINOK(LzmaProps_Decode(&propNew, props, propsSize));
   1135   RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));
   1136 
   1137   {
   1138     UInt32 dictSize = propNew.dicSize;
   1139     SizeT mask = ((UInt32)1 << 12) - 1;
   1140          if (dictSize >= ((UInt32)1 << 30)) mask = ((UInt32)1 << 22) - 1;
   1141     else if (dictSize >= ((UInt32)1 << 22)) mask = ((UInt32)1 << 20) - 1;;
   1142     dicBufSize = ((SizeT)dictSize + mask) & ~mask;
   1143     if (dicBufSize < dictSize)
   1144       dicBufSize = dictSize;
   1145   }
   1146 
   1147   if (!p->dic || dicBufSize != p->dicBufSize)
   1148   {
   1149     LzmaDec_FreeDict(p, alloc);
   1150     p->dic = (Byte *)ISzAlloc_Alloc(alloc, dicBufSize);
   1151     if (!p->dic)
   1152     {
   1153       LzmaDec_FreeProbs(p, alloc);
   1154       return SZ_ERROR_MEM;
   1155     }
   1156   }
   1157   p->dicBufSize = dicBufSize;
   1158   p->prop = propNew;
   1159   return SZ_OK;
   1160 }
   1161 
   1162 SRes LzmaDecode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen,
   1163     const Byte *propData, unsigned propSize, ELzmaFinishMode finishMode,
   1164     ELzmaStatus *status, ISzAllocPtr alloc)
   1165 {
   1166   CLzmaDec p;
   1167   SRes res;
   1168   SizeT outSize = *destLen, inSize = *srcLen;
   1169   *destLen = *srcLen = 0;
   1170   *status = LZMA_STATUS_NOT_SPECIFIED;
   1171   if (inSize < RC_INIT_SIZE)
   1172     return SZ_ERROR_INPUT_EOF;
   1173   LzmaDec_Construct(&p);
   1174   RINOK(LzmaDec_AllocateProbs(&p, propData, propSize, alloc));
   1175   p.dic = dest;
   1176   p.dicBufSize = outSize;
   1177   LzmaDec_Init(&p);
   1178   *srcLen = inSize;
   1179   res = LzmaDec_DecodeToDic(&p, outSize, src, srcLen, finishMode, status);
   1180   *destLen = p.dicPos;
   1181   if (res == SZ_OK && *status == LZMA_STATUS_NEEDS_MORE_INPUT)
   1182     res = SZ_ERROR_INPUT_EOF;
   1183   LzmaDec_FreeProbs(&p, alloc);
   1184   return res;
   1185 }