Mercurial > vba-clojure

     1 /* LzmaDec.c -- LZMA Decoder

     2 2008-11-06 : Igor Pavlov : Public domain */

     3 

     4 #include "LzmaDec.h"

     5 

     6 #include <string.h>

     7 

     8 #define kNumTopBits 24

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

    10 

    11 #define kNumBitModelTotalBits 11

    12 #define kBitModelTotal (1 << kNumBitModelTotalBits)

    13 #define kNumMoveBits 5

    14 

    15 #define RC_INIT_SIZE 5

    16 

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

    18 

    19 #define IF_BIT_0(p) ttt = *(p); NORMALIZE; bound = (range >> kNumBitModelTotalBits) * ttt; if (code < bound)

    20 #define UPDATE_0(p) range = bound; *(p) = (CLzmaProb)(ttt + ((kBitModelTotal - ttt) >> kNumMoveBits));

    21 #define UPDATE_1(p) range -= bound; code -= bound; *(p) = (CLzmaProb)(ttt - (ttt >> kNumMoveBits));

    22 #define GET_BIT2(p, i, A0, A1) IF_BIT_0(p) \

    23   { UPDATE_0(p); i = (i + i); A0; } else \

    24   { UPDATE_1(p); i = (i + i) + 1; A1; }

    25 #define GET_BIT(p, i) GET_BIT2(p, i, ; , ;)

    26 

    27 #define TREE_GET_BIT(probs, i) { GET_BIT((probs + i), i); }

    28 #define TREE_DECODE(probs, limit, i) \

    29   { i = 1; do { TREE_GET_BIT(probs, i); } while (i < limit); i -= limit; }

    30 

    31 /* #define _LZMA_SIZE_OPT */

    32 

    33 #ifdef _LZMA_SIZE_OPT

    34 #define TREE_6_DECODE(probs, i) TREE_DECODE(probs, (1 << 6), i)

    35 #else

    36 #define TREE_6_DECODE(probs, i) \

    37   { i = 1; \

    38   TREE_GET_BIT(probs, i); \

    39   TREE_GET_BIT(probs, i); \

    40   TREE_GET_BIT(probs, i); \

    41   TREE_GET_BIT(probs, i); \

    42   TREE_GET_BIT(probs, i); \

    43   TREE_GET_BIT(probs, i); \

    44   i -= 0x40; }

    45 #endif

    46 

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

    48 

    49 #define IF_BIT_0_CHECK(p) ttt = *(p); NORMALIZE_CHECK; bound = (range >> kNumBitModelTotalBits) * ttt; if (code < bound)

    50 #define UPDATE_0_CHECK range = bound;

    51 #define UPDATE_1_CHECK range -= bound; code -= bound;

    52 #define GET_BIT2_CHECK(p, i, A0, A1) IF_BIT_0_CHECK(p) \

    53   { UPDATE_0_CHECK; i = (i + i); A0; } else \

    54   { UPDATE_1_CHECK; i = (i + i) + 1; A1; }

    55 #define GET_BIT_CHECK(p, i) GET_BIT2_CHECK(p, i, ; , ;)

    56 #define TREE_DECODE_CHECK(probs, limit, i) \

    57   { i = 1; do { GET_BIT_CHECK(probs + i, i) } while (i < limit); i -= limit; }

    58 

    59 

    60 #define kNumPosBitsMax 4

    61 #define kNumPosStatesMax (1 << kNumPosBitsMax)

    62 

    63 #define kLenNumLowBits 3

    64 #define kLenNumLowSymbols (1 << kLenNumLowBits)

    65 #define kLenNumMidBits 3

    66 #define kLenNumMidSymbols (1 << kLenNumMidBits)

    67 #define kLenNumHighBits 8

    68 #define kLenNumHighSymbols (1 << kLenNumHighBits)

    69 

    70 #define LenChoice 0

    71 #define LenChoice2 (LenChoice + 1)

    72 #define LenLow (LenChoice2 + 1)

    73 #define LenMid (LenLow + (kNumPosStatesMax << kLenNumLowBits))

    74 #define LenHigh (LenMid + (kNumPosStatesMax << kLenNumMidBits))

    75 #define kNumLenProbs (LenHigh + kLenNumHighSymbols)

    76 

    77 

    78 #define kNumStates 12

    79 #define kNumLitStates 7

    80 

    81 #define kStartPosModelIndex 4

    82 #define kEndPosModelIndex 14

    83 #define kNumFullDistances (1 << (kEndPosModelIndex >> 1))

    84 

    85 #define kNumPosSlotBits 6

    86 #define kNumLenToPosStates 4

    87 

    88 #define kNumAlignBits 4

    89 #define kAlignTableSize (1 << kNumAlignBits)

    90 

    91 #define kMatchMinLen 2

    92 #define kMatchSpecLenStart (kMatchMinLen + kLenNumLowSymbols + kLenNumMidSymbols + kLenNumHighSymbols)

    93 

    94 #define IsMatch 0

    95 #define IsRep (IsMatch + (kNumStates << kNumPosBitsMax))

    96 #define IsRepG0 (IsRep + kNumStates)

    97 #define IsRepG1 (IsRepG0 + kNumStates)

    98 #define IsRepG2 (IsRepG1 + kNumStates)

    99 #define IsRep0Long (IsRepG2 + kNumStates)

   100 #define PosSlot (IsRep0Long + (kNumStates << kNumPosBitsMax))

   101 #define SpecPos (PosSlot + (kNumLenToPosStates << kNumPosSlotBits))

   102 #define Align (SpecPos + kNumFullDistances - kEndPosModelIndex)

   103 #define LenCoder (Align + kAlignTableSize)

   104 #define RepLenCoder (LenCoder + kNumLenProbs)

   105 #define Literal (RepLenCoder + kNumLenProbs)

   106 

   107 #define LZMA_BASE_SIZE 1846

   108 #define LZMA_LIT_SIZE 768

   109 

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

   111 

   112 #if Literal != LZMA_BASE_SIZE

   113 StopCompilingDueBUG

   114 #endif

   115 

   116 static const Byte kLiteralNextStates[kNumStates * 2] =

   117 {

   118   0, 0, 0, 0, 1, 2, 3,  4,  5,  6,  4,  5,

   119   7, 7, 7, 7, 7, 7, 7, 10, 10, 10, 10, 10

   120 };

   121 

   122 #define LZMA_DIC_MIN (1 << 12)

   123 

   124 /* First LZMA-symbol is always decoded.

   125 And it decodes new LZMA-symbols while (buf < bufLimit), but "buf" is without last normalization

   126 Out:

   127   Result:

   128     SZ_OK - OK

   129     SZ_ERROR_DATA - Error

   130   p->remainLen:

   131     < kMatchSpecLenStart : normal remain

   132     = kMatchSpecLenStart : finished

   133     = kMatchSpecLenStart + 1 : Flush marker

   134     = kMatchSpecLenStart + 2 : State Init Marker

   135 */

   136 

   137 static int MY_FAST_CALL LzmaDec_DecodeReal(CLzmaDec *p, SizeT limit, const Byte *bufLimit)

   138 {

   139   CLzmaProb *probs = p->probs;

   140 

   141   unsigned state = p->state;

   142   UInt32 rep0 = p->reps[0], rep1 = p->reps[1], rep2 = p->reps[2], rep3 = p->reps[3];

   143   unsigned pbMask = ((unsigned)1 << (p->prop.pb)) - 1;

   144   unsigned lpMask = ((unsigned)1 << (p->prop.lp)) - 1;

   145   unsigned lc = p->prop.lc;

   146 

   147   Byte *dic = p->dic;

   148   SizeT dicBufSize = p->dicBufSize;

   149   SizeT dicPos = p->dicPos;

   150   

   151   UInt32 processedPos = p->processedPos;

   152   UInt32 checkDicSize = p->checkDicSize;

   153   unsigned len = 0;

   154 

   155   const Byte *buf = p->buf;

   156   UInt32 range = p->range;

   157   UInt32 code = p->code;

   158 

   159   do

   160   {

   161     CLzmaProb *prob;

   162     UInt32 bound;

   163     unsigned ttt;

   164     unsigned posState = processedPos & pbMask;

   165 

   166     prob = probs + IsMatch + (state << kNumPosBitsMax) + posState;

   167     IF_BIT_0(prob)

   168     {

   169       unsigned symbol;

   170       UPDATE_0(prob);

   171       prob = probs + Literal;

   172       if (checkDicSize != 0 || processedPos != 0)

   173         prob += (LZMA_LIT_SIZE * (((processedPos & lpMask) << lc) +

   174         (dic[(dicPos == 0 ? dicBufSize : dicPos) - 1] >> (8 - lc))));

   175 

   176       if (state < kNumLitStates)

   177       {

   178         symbol = 1;

   179         do { GET_BIT(prob + symbol, symbol) } while (symbol < 0x100);

   180       }

   181       else

   182       {

   183         unsigned matchByte = p->dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];

   184         unsigned offs = 0x100;

   185         symbol = 1;

   186         do

   187         {

   188           unsigned bit;

   189           CLzmaProb *probLit;

   190           matchByte <<= 1;

   191           bit = (matchByte & offs);

   192           probLit = prob + offs + bit + symbol;

   193           GET_BIT2(probLit, symbol, offs &= ~bit, offs &= bit)

   194         }

   195         while (symbol < 0x100);

   196       }

   197       dic[dicPos++] = (Byte)(symbol & 0xFF);

   198       processedPos++;

   199 

   200       state = kLiteralNextStates[state];

   201       /* if (state < 4) state = 0; else if (state < 10) state -= 3; else state -= 6; */

   202       continue;

   203     }

   204     else

   205     {

   206       UPDATE_1(prob);

   207       prob = probs + IsRep + state;

   208       IF_BIT_0(prob)

   209       {

   210         UPDATE_0(prob);

   211         state += kNumStates;

   212         prob = probs + LenCoder;

   213       }

   214       else

   215       {

   216         UPDATE_1(prob);

   217         if (checkDicSize == 0 && processedPos == 0)

   218           return SZ_ERROR_DATA;

   219         prob = probs + IsRepG0 + state;

   220         IF_BIT_0(prob)

   221         {

   222           UPDATE_0(prob);

   223           prob = probs + IsRep0Long + (state << kNumPosBitsMax) + posState;

   224           IF_BIT_0(prob)

   225           {

   226             UPDATE_0(prob);

   227             dic[dicPos] = dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];

   228             dicPos++;

   229             processedPos++;

   230             state = state < kNumLitStates ? 9 : 11;

   231             continue;

   232           }

   233           UPDATE_1(prob);

   234         }

   235         else

   236         {

   237           UInt32 distance;

   238           UPDATE_1(prob);

   239           prob = probs + IsRepG1 + state;

   240           IF_BIT_0(prob)

   241           {

   242             UPDATE_0(prob);

   243             distance = rep1;

   244           }

   245           else

   246           {

   247             UPDATE_1(prob);

   248             prob = probs + IsRepG2 + state;

   249             IF_BIT_0(prob)

   250             {

   251               UPDATE_0(prob);

   252               distance = rep2;

   253             }

   254             else

   255             {

   256               UPDATE_1(prob);

   257               distance = rep3;

   258               rep3 = rep2;

   259             }

   260             rep2 = rep1;

   261           }

   262           rep1 = rep0;

   263           rep0 = distance;

   264         }

   265         state = state < kNumLitStates ? 8 : 11;

   266         prob = probs + RepLenCoder;

   267       }

   268       {

   269         unsigned limit, offset;

   270         CLzmaProb *probLen = prob + LenChoice;

   271         IF_BIT_0(probLen)

   272         {

   273           UPDATE_0(probLen);

   274           probLen = prob + LenLow + (posState << kLenNumLowBits);

   275           offset = 0;

   276           limit = (1 << kLenNumLowBits);

   277         }

   278         else

   279         {

   280           UPDATE_1(probLen);

   281           probLen = prob + LenChoice2;

   282           IF_BIT_0(probLen)

   283           {

   284             UPDATE_0(probLen);

   285             probLen = prob + LenMid + (posState << kLenNumMidBits);

   286             offset = kLenNumLowSymbols;

   287             limit = (1 << kLenNumMidBits);

   288           }

   289           else

   290           {

   291             UPDATE_1(probLen);

   292             probLen = prob + LenHigh;

   293             offset = kLenNumLowSymbols + kLenNumMidSymbols;

   294             limit = (1 << kLenNumHighBits);

   295           }

   296         }

   297         TREE_DECODE(probLen, limit, len);

   298         len += offset;

   299       }

   300 

   301       if (state >= kNumStates)

   302       {

   303         UInt32 distance;

   304         prob = probs + PosSlot +

   305             ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) << kNumPosSlotBits);

   306         TREE_6_DECODE(prob, distance);

   307         if (distance >= kStartPosModelIndex)

   308         {

   309           unsigned posSlot = (unsigned)distance;

   310           int numDirectBits = (int)(((distance >> 1) - 1));

   311           distance = (2 | (distance & 1));

   312           if (posSlot < kEndPosModelIndex)

   313           {

   314             distance <<= numDirectBits;

   315             prob = probs + SpecPos + distance - posSlot - 1;

   316             {

   317               UInt32 mask = 1;

   318               unsigned i = 1;

   319               do

   320               {

   321                 GET_BIT2(prob + i, i, ; , distance |= mask);

   322                 mask <<= 1;

   323               }

   324               while (--numDirectBits != 0);

   325             }

   326           }

   327           else

   328           {

   329             numDirectBits -= kNumAlignBits;

   330             do

   331             {

   332               NORMALIZE

   333               range >>= 1;

   334               

   335               {

   336                 UInt32 t;

   337                 code -= range;

   338                 t = (0 - ((UInt32)code >> 31)); /* (UInt32)((Int32)code >> 31) */

   339                 distance = (distance << 1) + (t + 1);

   340                 code += range & t;

   341               }

   342               /*

   343               distance <<= 1;

   344               if (code >= range)

   345               {

   346                 code -= range;

   347                 distance |= 1;

   348               }

   349               */

   350             }

   351             while (--numDirectBits != 0);

   352             prob = probs + Align;

   353             distance <<= kNumAlignBits;

   354             {

   355               unsigned i = 1;

   356               GET_BIT2(prob + i, i, ; , distance |= 1);

   357               GET_BIT2(prob + i, i, ; , distance |= 2);

   358               GET_BIT2(prob + i, i, ; , distance |= 4);

   359               GET_BIT2(prob + i, i, ; , distance |= 8);

   360             }

   361             if (distance == (UInt32)0xFFFFFFFF)

   362             {

   363               len += kMatchSpecLenStart;

   364               state -= kNumStates;

   365               break;

   366             }

   367           }

   368         }

   369         rep3 = rep2;

   370         rep2 = rep1;

   371         rep1 = rep0;

   372         rep0 = distance + 1;

   373         if (checkDicSize == 0)

   374         {

   375           if (distance >= processedPos)

   376             return SZ_ERROR_DATA;

   377         }

   378         else if (distance >= checkDicSize)

   379           return SZ_ERROR_DATA;

   380         state = (state < kNumStates + kNumLitStates) ? kNumLitStates : kNumLitStates + 3;

   381         /* state = kLiteralNextStates[state]; */

   382       }

   383 

   384       len += kMatchMinLen;

   385 

   386       if (limit == dicPos)

   387         return SZ_ERROR_DATA;

   388       {

   389         SizeT rem = limit - dicPos;

   390         unsigned curLen = ((rem < len) ? (unsigned)rem : len);

   391         SizeT pos = (dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0);

   392 

   393         processedPos += curLen;

   394 

   395         len -= curLen;

   396         if (pos + curLen <= dicBufSize)

   397         {

   398           Byte *dest = dic + dicPos;

   399           ptrdiff_t src = (ptrdiff_t)pos - (ptrdiff_t)dicPos;

   400           const Byte *lim = dest + curLen;

   401           dicPos += curLen;

   402           do

   403             *(dest) = (Byte)*(dest + src);

   404           while (++dest != lim);

   405         }

   406         else

   407         {

   408           do

   409           {

   410             dic[dicPos++] = dic[pos];

   411             if (++pos == dicBufSize)

   412               pos = 0;

   413           }

   414           while (--curLen != 0);

   415         }

   416       }

   417     }

   418   }

   419   while (dicPos < limit && buf < bufLimit);

   420   NORMALIZE;

   421   p->buf = buf;

   422   p->range = range;

   423   p->code = code;

   424   p->remainLen = len;

   425   p->dicPos = dicPos;

   426   p->processedPos = processedPos;

   427   p->reps[0] = rep0;

   428   p->reps[1] = rep1;

   429   p->reps[2] = rep2;

   430   p->reps[3] = rep3;

   431   p->state = state;

   432 

   433   return SZ_OK;

   434 }

   435 

   436 static void MY_FAST_CALL LzmaDec_WriteRem(CLzmaDec *p, SizeT limit)

   437 {

   438   if (p->remainLen != 0 && p->remainLen < kMatchSpecLenStart)

   439   {

   440     Byte *dic = p->dic;

   441     SizeT dicPos = p->dicPos;

   442     SizeT dicBufSize = p->dicBufSize;

   443     unsigned len = p->remainLen;

   444     UInt32 rep0 = p->reps[0];

   445     if (limit - dicPos < len)

   446       len = (unsigned)(limit - dicPos);

   447 

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

   449       p->checkDicSize = p->prop.dicSize;

   450 

   451     p->processedPos += len;

   452     p->remainLen -= len;

   453     while (len-- != 0)

   454     {

   455       dic[dicPos] = dic[(dicPos - rep0) + ((dicPos < rep0) ? dicBufSize : 0)];

   456       dicPos++;

   457     }

   458     p->dicPos = dicPos;

   459   }

   460 }

   461 

   462 static int MY_FAST_CALL LzmaDec_DecodeReal2(CLzmaDec *p, SizeT limit, const Byte *bufLimit)

   463 {

   464   do

   465   {

   466     SizeT limit2 = limit;

   467     if (p->checkDicSize == 0)

   468     {

   469       UInt32 rem = p->prop.dicSize - p->processedPos;

   470       if (limit - p->dicPos > rem)

   471         limit2 = p->dicPos + rem;

   472     }

   473     RINOK(LzmaDec_DecodeReal(p, limit2, bufLimit));

   474     if (p->processedPos >= p->prop.dicSize)

   475       p->checkDicSize = p->prop.dicSize;

   476     LzmaDec_WriteRem(p, limit);

   477   }

   478   while (p->dicPos < limit && p->buf < bufLimit && p->remainLen < kMatchSpecLenStart);

   479 

   480   if (p->remainLen > kMatchSpecLenStart)

   481   {

   482     p->remainLen = kMatchSpecLenStart;

   483   }

   484   return 0;

   485 }

   486 

   487 typedef enum

   488 {

   489   DUMMY_ERROR, /* unexpected end of input stream */

   490   DUMMY_LIT,

   491   DUMMY_MATCH,

   492   DUMMY_REP

   493 } ELzmaDummy;

   494 

   495 static ELzmaDummy LzmaDec_TryDummy(const CLzmaDec *p, const Byte *buf, SizeT inSize)

   496 {

   497   UInt32 range = p->range;

   498   UInt32 code = p->code;

   499   const Byte *bufLimit = buf + inSize;

   500   CLzmaProb *probs = p->probs;

   501   unsigned state = p->state;

   502   ELzmaDummy res;

   503 

   504   {

   505     CLzmaProb *prob;

   506     UInt32 bound;

   507     unsigned ttt;

   508     unsigned posState = (p->processedPos) & ((1 << p->prop.pb) - 1);

   509 

   510     prob = probs + IsMatch + (state << kNumPosBitsMax) + posState;

   511     IF_BIT_0_CHECK(prob)

   512     {

   513       UPDATE_0_CHECK

   514 

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

   516 

   517       prob = probs + Literal;

   518       if (p->checkDicSize != 0 || p->processedPos != 0)

   519         prob += (LZMA_LIT_SIZE *

   520           ((((p->processedPos) & ((1 << (p->prop.lp)) - 1)) << p->prop.lc) +

   521           (p->dic[(p->dicPos == 0 ? p->dicBufSize : p->dicPos) - 1] >> (8 - p->prop.lc))));

   522 

   523       if (state < kNumLitStates)

   524       {

   525         unsigned symbol = 1;

   526         do { GET_BIT_CHECK(prob + symbol, symbol) } while (symbol < 0x100);

   527       }

   528       else

   529       {

   530         unsigned matchByte = p->dic[p->dicPos - p->reps[0] +

   531             ((p->dicPos < p->reps[0]) ? p->dicBufSize : 0)];

   532         unsigned offs = 0x100;

   533         unsigned symbol = 1;

   534         do

   535         {

   536           unsigned bit;

   537           CLzmaProb *probLit;

   538           matchByte <<= 1;

   539           bit = (matchByte & offs);

   540           probLit = prob + offs + bit + symbol;

   541           GET_BIT2_CHECK(probLit, symbol, offs &= ~bit, offs &= bit)

   542         }

   543         while (symbol < 0x100);

   544       }

   545       res = DUMMY_LIT;

   546     }

   547     else

   548     {

   549       unsigned len;

   550       UPDATE_1_CHECK;

   551 

   552       prob = probs + IsRep + state;

   553       IF_BIT_0_CHECK(prob)

   554       {

   555         UPDATE_0_CHECK;

   556         state = 0;

   557         prob = probs + LenCoder;

   558         res = DUMMY_MATCH;

   559       }

   560       else

   561       {

   562         UPDATE_1_CHECK;

   563         res = DUMMY_REP;

   564         prob = probs + IsRepG0 + state;

   565         IF_BIT_0_CHECK(prob)

   566         {

   567           UPDATE_0_CHECK;

   568           prob = probs + IsRep0Long + (state << kNumPosBitsMax) + posState;

   569           IF_BIT_0_CHECK(prob)

   570           {

   571             UPDATE_0_CHECK;

   572             NORMALIZE_CHECK;

   573             return DUMMY_REP;

   574           }

   575           else

   576           {

   577             UPDATE_1_CHECK;

   578           }

   579         }

   580         else

   581         {

   582           UPDATE_1_CHECK;

   583           prob = probs + IsRepG1 + state;

   584           IF_BIT_0_CHECK(prob)

   585           {

   586             UPDATE_0_CHECK;

   587           }

   588           else

   589           {

   590             UPDATE_1_CHECK;

   591             prob = probs + IsRepG2 + state;

   592             IF_BIT_0_CHECK(prob)

   593             {

   594               UPDATE_0_CHECK;

   595             }

   596             else

   597             {

   598               UPDATE_1_CHECK;

   599             }

   600           }

   601         }

   602         state = kNumStates;

   603         prob = probs + RepLenCoder;

   604       }

   605       {

   606         unsigned limit, offset;

   607         CLzmaProb *probLen = prob + LenChoice;

   608         IF_BIT_0_CHECK(probLen)

   609         {

   610           UPDATE_0_CHECK;

   611           probLen = prob + LenLow + (posState << kLenNumLowBits);

   612           offset = 0;

   613           limit = 1 << kLenNumLowBits;

   614         }

   615         else

   616         {

   617           UPDATE_1_CHECK;

   618           probLen = prob + LenChoice2;

   619           IF_BIT_0_CHECK(probLen)

   620           {

   621             UPDATE_0_CHECK;

   622             probLen = prob + LenMid + (posState << kLenNumMidBits);

   623             offset = kLenNumLowSymbols;

   624             limit = 1 << kLenNumMidBits;

   625           }

   626           else

   627           {

   628             UPDATE_1_CHECK;

   629             probLen = prob + LenHigh;

   630             offset = kLenNumLowSymbols + kLenNumMidSymbols;

   631             limit = 1 << kLenNumHighBits;

   632           }

   633         }

   634         TREE_DECODE_CHECK(probLen, limit, len);

   635         len += offset;

   636       }

   637 

   638       if (state < 4)

   639       {

   640         unsigned posSlot;

   641         prob = probs + PosSlot +

   642             ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) <<

   643             kNumPosSlotBits);

   644         TREE_DECODE_CHECK(prob, 1 << kNumPosSlotBits, posSlot);

   645         if (posSlot >= kStartPosModelIndex)

   646         {

   647           int numDirectBits = ((posSlot >> 1) - 1);

   648 

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

   650 

   651           if (posSlot < kEndPosModelIndex)

   652           {

   653             prob = probs + SpecPos + ((2 | (posSlot & 1)) << numDirectBits) - posSlot - 1;

   654           }

   655           else

   656           {

   657             numDirectBits -= kNumAlignBits;

   658             do

   659             {

   660               NORMALIZE_CHECK

   661               range >>= 1;

   662               code -= range & (((code - range) >> 31) - 1);

   663               /* if (code >= range) code -= range; */

   664             }

   665             while (--numDirectBits != 0);

   666             prob = probs + Align;

   667             numDirectBits = kNumAlignBits;

   668           }

   669           {

   670             unsigned i = 1;

   671             do

   672             {

   673               GET_BIT_CHECK(prob + i, i);

   674             }

   675             while (--numDirectBits != 0);

   676           }

   677         }

   678       }

   679     }

   680   }

   681   NORMALIZE_CHECK;

   682   return res;

   683 }

   684 

   685 

   686 static void LzmaDec_InitRc(CLzmaDec *p, const Byte *data)

   687 {

   688   p->code = ((UInt32)data[1] << 24) | ((UInt32)data[2] << 16) | ((UInt32)data[3] << 8) | ((UInt32)data[4]);

   689   p->range = 0xFFFFFFFF;

   690   p->needFlush = 0;

   691 }

   692 

   693 void LzmaDec_InitDicAndState(CLzmaDec *p, Bool initDic, Bool initState)

   694 {

   695   p->needFlush = 1;

   696   p->remainLen = 0;

   697   p->tempBufSize = 0;

   698 

   699   if (initDic)

   700   {

   701     p->processedPos = 0;

   702     p->checkDicSize = 0;

   703     p->needInitState = 1;

   704   }

   705   if (initState)

   706     p->needInitState = 1;

   707 }

   708 

   709 void LzmaDec_Init(CLzmaDec *p)

   710 {

   711   p->dicPos = 0;

   712   LzmaDec_InitDicAndState(p, True, True);

   713 }

   714 

   715 static void LzmaDec_InitStateReal(CLzmaDec *p)

   716 {

   717   UInt32 numProbs = Literal + ((UInt32)LZMA_LIT_SIZE << (p->prop.lc + p->prop.lp));

   718   UInt32 i;

   719   CLzmaProb *probs = p->probs;

   720   for (i = 0; i < numProbs; i++)

   721     probs[i] = kBitModelTotal >> 1;

   722   p->reps[0] = p->reps[1] = p->reps[2] = p->reps[3] = 1;

   723   p->state = 0;

   724   p->needInitState = 0;

   725 }

   726 

   727 SRes LzmaDec_DecodeToDic(CLzmaDec *p, SizeT dicLimit, const Byte *src, SizeT *srcLen,

   728     ELzmaFinishMode finishMode, ELzmaStatus *status)

   729 {

   730   SizeT inSize = *srcLen;

   731   (*srcLen) = 0;

   732   LzmaDec_WriteRem(p, dicLimit);

   733   

   734   *status = LZMA_STATUS_NOT_SPECIFIED;

   735 

   736   while (p->remainLen != kMatchSpecLenStart)

   737   {

   738       int checkEndMarkNow;

   739 

   740       if (p->needFlush != 0)

   741       {

   742         for (; inSize > 0 && p->tempBufSize < RC_INIT_SIZE; (*srcLen)++, inSize--)

   743           p->tempBuf[p->tempBufSize++] = *src++;

   744         if (p->tempBufSize < RC_INIT_SIZE)

   745         {

   746           *status = LZMA_STATUS_NEEDS_MORE_INPUT;

   747           return SZ_OK;

   748         }

   749         if (p->tempBuf[0] != 0)

   750           return SZ_ERROR_DATA;

   751 

   752         LzmaDec_InitRc(p, p->tempBuf);

   753         p->tempBufSize = 0;

   754       }

   755 

   756       checkEndMarkNow = 0;

   757       if (p->dicPos >= dicLimit)

   758       {

   759         if (p->remainLen == 0 && p->code == 0)

   760         {

   761           *status = LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK;

   762           return SZ_OK;

   763         }

   764         if (finishMode == LZMA_FINISH_ANY)

   765         {

   766           *status = LZMA_STATUS_NOT_FINISHED;

   767           return SZ_OK;

   768         }

   769         if (p->remainLen != 0)

   770         {

   771           *status = LZMA_STATUS_NOT_FINISHED;

   772           return SZ_ERROR_DATA;

   773         }

   774         checkEndMarkNow = 1;

   775       }

   776 

   777       if (p->needInitState)

   778         LzmaDec_InitStateReal(p);

   779   

   780       if (p->tempBufSize == 0)

   781       {

   782         SizeT processed;

   783         const Byte *bufLimit;

   784         if (inSize < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow)

   785         {

   786           int dummyRes = LzmaDec_TryDummy(p, src, inSize);

   787           if (dummyRes == DUMMY_ERROR)

   788           {

   789             memcpy(p->tempBuf, src, inSize);

   790             p->tempBufSize = (unsigned)inSize;

   791             (*srcLen) += inSize;

   792             *status = LZMA_STATUS_NEEDS_MORE_INPUT;

   793             return SZ_OK;

   794           }

   795           if (checkEndMarkNow && dummyRes != DUMMY_MATCH)

   796           {

   797             *status = LZMA_STATUS_NOT_FINISHED;

   798             return SZ_ERROR_DATA;

   799           }

   800           bufLimit = src;

   801         }

   802         else

   803           bufLimit = src + inSize - LZMA_REQUIRED_INPUT_MAX;

   804         p->buf = src;

   805         if (LzmaDec_DecodeReal2(p, dicLimit, bufLimit) != 0)

   806           return SZ_ERROR_DATA;

   807         processed = (SizeT)(p->buf - src);

   808         (*srcLen) += processed;

   809         src += processed;

   810         inSize -= processed;

   811       }

   812       else

   813       {

   814         unsigned rem = p->tempBufSize, lookAhead = 0;

   815         while (rem < LZMA_REQUIRED_INPUT_MAX && lookAhead < inSize)

   816           p->tempBuf[rem++] = src[lookAhead++];

   817         p->tempBufSize = rem;

   818         if (rem < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow)

   819         {

   820           int dummyRes = LzmaDec_TryDummy(p, p->tempBuf, rem);

   821           if (dummyRes == DUMMY_ERROR)

   822           {

   823             (*srcLen) += lookAhead;

   824             *status = LZMA_STATUS_NEEDS_MORE_INPUT;

   825             return SZ_OK;

   826           }

   827           if (checkEndMarkNow && dummyRes != DUMMY_MATCH)

   828           {

   829             *status = LZMA_STATUS_NOT_FINISHED;

   830             return SZ_ERROR_DATA;

   831           }

   832         }

   833         p->buf = p->tempBuf;

   834         if (LzmaDec_DecodeReal2(p, dicLimit, p->buf) != 0)

   835           return SZ_ERROR_DATA;

   836         lookAhead -= (rem - (unsigned)(p->buf - p->tempBuf));

   837         (*srcLen) += lookAhead;

   838         src += lookAhead;

   839         inSize -= lookAhead;

   840         p->tempBufSize = 0;

   841       }

   842   }

   843   if (p->code == 0)

   844     *status = LZMA_STATUS_FINISHED_WITH_MARK;

   845   return (p->code == 0) ? SZ_OK : SZ_ERROR_DATA;

   846 }

   847 

   848 SRes LzmaDec_DecodeToBuf(CLzmaDec *p, Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status)

   849 {

   850   SizeT outSize = *destLen;

   851   SizeT inSize = *srcLen;

   852   *srcLen = *destLen = 0;

   853   for (;;)

   854   {

   855     SizeT inSizeCur = inSize, outSizeCur, dicPos;

   856     ELzmaFinishMode curFinishMode;

   857     SRes res;

   858     if (p->dicPos == p->dicBufSize)

   859       p->dicPos = 0;

   860     dicPos = p->dicPos;

   861     if (outSize > p->dicBufSize - dicPos)

   862     {

   863       outSizeCur = p->dicBufSize;

   864       curFinishMode = LZMA_FINISH_ANY;

   865     }

   866     else

   867     {

   868       outSizeCur = dicPos + outSize;

   869       curFinishMode = finishMode;

   870     }

   871 

   872     res = LzmaDec_DecodeToDic(p, outSizeCur, src, &inSizeCur, curFinishMode, status);

   873     src += inSizeCur;

   874     inSize -= inSizeCur;

   875     *srcLen += inSizeCur;

   876     outSizeCur = p->dicPos - dicPos;

   877     memcpy(dest, p->dic + dicPos, outSizeCur);

   878     dest += outSizeCur;

   879     outSize -= outSizeCur;

   880     *destLen += outSizeCur;

   881     if (res != 0)

   882       return res;

   883     if (outSizeCur == 0 || outSize == 0)

   884       return SZ_OK;

   885   }

   886 }

   887 

   888 void LzmaDec_FreeProbs(CLzmaDec *p, ISzAlloc *alloc)

   889 {

   890   alloc->Free(alloc, p->probs);

   891   p->probs = 0;

   892 }

   893 

   894 static void LzmaDec_FreeDict(CLzmaDec *p, ISzAlloc *alloc)

   895 {

   896   alloc->Free(alloc, p->dic);

   897   p->dic = 0;

   898 }

   899 

   900 void LzmaDec_Free(CLzmaDec *p, ISzAlloc *alloc)

   901 {

   902   LzmaDec_FreeProbs(p, alloc);

   903   LzmaDec_FreeDict(p, alloc);

   904 }

   905 

   906 SRes LzmaProps_Decode(CLzmaProps *p, const Byte *data, unsigned size)

   907 {

   908   UInt32 dicSize;

   909   Byte d;

   910   

   911   if (size < LZMA_PROPS_SIZE)

   912     return SZ_ERROR_UNSUPPORTED;

   913   else

   914     dicSize = data[1] | ((UInt32)data[2] << 8) | ((UInt32)data[3] << 16) | ((UInt32)data[4] << 24);

   915  

   916   if (dicSize < LZMA_DIC_MIN)

   917     dicSize = LZMA_DIC_MIN;

   918   p->dicSize = dicSize;

   919 

   920   d = data[0];

   921   if (d >= (9 * 5 * 5))

   922     return SZ_ERROR_UNSUPPORTED;

   923 

   924   p->lc = d % 9;

   925   d /= 9;

   926   p->pb = d / 5;

   927   p->lp = d % 5;

   928 

   929   return SZ_OK;

   930 }

   931 

   932 static SRes LzmaDec_AllocateProbs2(CLzmaDec *p, const CLzmaProps *propNew, ISzAlloc *alloc)

   933 {

   934   UInt32 numProbs = LzmaProps_GetNumProbs(propNew);

   935   if (p->probs == 0 || numProbs != p->numProbs)

   936   {

   937     LzmaDec_FreeProbs(p, alloc);

   938     p->probs = (CLzmaProb *)alloc->Alloc(alloc, numProbs * sizeof(CLzmaProb));

   939     p->numProbs = numProbs;

   940     if (p->probs == 0)

   941       return SZ_ERROR_MEM;

   942   }

   943   return SZ_OK;

   944 }

   945 

   946 SRes LzmaDec_AllocateProbs(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAlloc *alloc)

   947 {

   948   CLzmaProps propNew;

   949   RINOK(LzmaProps_Decode(&propNew, props, propsSize));

   950   RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));

   951   p->prop = propNew;

   952   return SZ_OK;

   953 }

   954 

   955 SRes LzmaDec_Allocate(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAlloc *alloc)

   956 {

   957   CLzmaProps propNew;

   958   SizeT dicBufSize;

   959   RINOK(LzmaProps_Decode(&propNew, props, propsSize));

   960   RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc));

   961   dicBufSize = propNew.dicSize;

   962   if (p->dic == 0 || dicBufSize != p->dicBufSize)

   963   {

   964     LzmaDec_FreeDict(p, alloc);

   965     p->dic = (Byte *)alloc->Alloc(alloc, dicBufSize);

   966     if (p->dic == 0)

   967     {

   968       LzmaDec_FreeProbs(p, alloc);

   969       return SZ_ERROR_MEM;

   970     }

   971   }

   972   p->dicBufSize = dicBufSize;

   973   p->prop = propNew;

   974   return SZ_OK;

   975 }

   976 

   977 SRes LzmaDecode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen,

   978     const Byte *propData, unsigned propSize, ELzmaFinishMode finishMode,

   979     ELzmaStatus *status, ISzAlloc *alloc)

   980 {

   981   CLzmaDec p;

   982   SRes res;

   983   SizeT inSize = *srcLen;

   984   SizeT outSize = *destLen;

   985   *srcLen = *destLen = 0;

   986   if (inSize < RC_INIT_SIZE)

   987     return SZ_ERROR_INPUT_EOF;

   988 

   989   LzmaDec_Construct(&p);

   990   res = LzmaDec_AllocateProbs(&p, propData, propSize, alloc);

   991   if (res != 0)

   992     return res;

   993   p.dic = dest;

   994   p.dicBufSize = outSize;

   995 

   996   LzmaDec_Init(&p);

   997   

   998   *srcLen = inSize;

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

  1000 

  1001   if (res == SZ_OK && *status == LZMA_STATUS_NEEDS_MORE_INPUT)

  1002     res = SZ_ERROR_INPUT_EOF;

  1003 

  1004   (*destLen) = p.dicPos;

  1005   LzmaDec_FreeProbs(&p, alloc);

  1006   return res;

  1007 }
author	Robert McIntyre <rlm@mit.edu>
date	Sat, 03 Mar 2012 10:31:27 -0600
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