The Tor Browser / file revision

other-licenses/7zstub/src/7zip/Compress/LZMA/LZMADecoder.cpp@97036ab72558

other-licenses/7zstub/src/7zip/Compress/LZMA/LZMADecoder.cpp

Tue, 06 Jan 2015 21:39:09 +0100

author
Michael Schloh von Bennewitz <michael@schloh.com>
date
Tue, 06 Jan 2015 21:39:09 +0100
branch
TOR_BUG_9701
changeset 8
97036ab72558
permissions
-rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

     1 // LZMADecoder.cpp

     2 

     3 #include "StdAfx.h"

     4 

     5 #include "LZMADecoder.h"

     6 #include "../../../Common/Defs.h"

     7 

     8 namespace NCompress {

     9 namespace NLZMA {

    10 

    11 const int kLenIdFinished = -1;

    12 const int kLenIdNeedInit = -2;

    13 

    14 void CDecoder::Init()

    15 {

    16   { 

    17     for(int i = 0; i < kNumStates; i++)

    18     {

    19       for (UInt32 j = 0; j <= _posStateMask; j++)

    20       {

    21         _isMatch[i][j].Init();

    22         _isRep0Long[i][j].Init();

    23       }

    24       _isRep[i].Init();

    25       _isRepG0[i].Init();

    26       _isRepG1[i].Init();

    27       _isRepG2[i].Init();

    28     }

    29   }

    30   { 

    31     for (UInt32 i = 0; i < kNumLenToPosStates; i++)

    32     _posSlotDecoder[i].Init();

    33   }

    34   { 

    35     for(UInt32 i = 0; i < kNumFullDistances - kEndPosModelIndex; i++)

    36       _posDecoders[i].Init();

    37   }

    38   _posAlignDecoder.Init();

    39   _lenDecoder.Init(_posStateMask + 1);

    40   _repMatchLenDecoder.Init(_posStateMask + 1);

    41   _literalDecoder.Init();

    42 

    43   _state.Init();

    44   _reps[0] = _reps[1] = _reps[2] = _reps[3] = 0;

    45 }

    46 

    47 HRESULT CDecoder::CodeSpec(UInt32 curSize)

    48 {

    49   if (_outSizeDefined)

    50   {

    51     const UInt64 rem = _outSize - _outWindowStream.GetProcessedSize();

    52     if (curSize > rem)

    53       curSize = (UInt32)rem;

    54   }

    55 

    56   if (_remainLen == kLenIdFinished)

    57     return S_OK;

    58   if (_remainLen == kLenIdNeedInit)

    59   {

    60     _rangeDecoder.Init();

    61     Init();

    62     _remainLen = 0;

    63   }

    64   if (curSize == 0)

    65     return S_OK;

    66 

    67   UInt32 rep0 = _reps[0];

    68   UInt32 rep1 = _reps[1];

    69   UInt32 rep2 = _reps[2];

    70   UInt32 rep3 = _reps[3];

    71   CState state = _state;

    72   Byte previousByte;

    73 

    74   while(_remainLen > 0 && curSize > 0)

    75   {

    76     previousByte = _outWindowStream.GetByte(rep0);

    77     _outWindowStream.PutByte(previousByte);

    78     _remainLen--;

    79     curSize--;

    80   }

    81   UInt64 nowPos64 = _outWindowStream.GetProcessedSize();

    82   if (nowPos64 == 0)

    83     previousByte = 0;

    84   else

    85     previousByte = _outWindowStream.GetByte(0);

    86 

    87   while(curSize > 0)

    88   {

    89     {

    90       #ifdef _NO_EXCEPTIONS

    91       if (_rangeDecoder.Stream.ErrorCode != S_OK)

    92         return _rangeDecoder.Stream.ErrorCode;

    93       #endif

    94       if (_rangeDecoder.Stream.WasFinished())

    95         return S_FALSE;

    96       UInt32 posState = UInt32(nowPos64) & _posStateMask;

    97       if (_isMatch[state.Index][posState].Decode(&_rangeDecoder) == 0)

    98       {

    99         if(!state.IsCharState())

   100           previousByte = _literalDecoder.DecodeWithMatchByte(&_rangeDecoder, 

   101               (UInt32)nowPos64, previousByte, _outWindowStream.GetByte(rep0));

   102         else

   103           previousByte = _literalDecoder.DecodeNormal(&_rangeDecoder, 

   104               (UInt32)nowPos64, previousByte);

   105         _outWindowStream.PutByte(previousByte);

   106         state.UpdateChar();

   107         curSize--;

   108         nowPos64++;

   109       }

   110       else             

   111       {

   112         UInt32 len;

   113         if(_isRep[state.Index].Decode(&_rangeDecoder) == 1)

   114         {

   115           len = 0;

   116           if(_isRepG0[state.Index].Decode(&_rangeDecoder) == 0)

   117           {

   118             if(_isRep0Long[state.Index][posState].Decode(&_rangeDecoder) == 0)

   119             {

   120               state.UpdateShortRep();

   121               len = 1;

   122             }

   123           }

   124           else

   125           {

   126             UInt32 distance;

   127             if(_isRepG1[state.Index].Decode(&_rangeDecoder) == 0)

   128               distance = rep1;

   129             else 

   130             {

   131               if (_isRepG2[state.Index].Decode(&_rangeDecoder) == 0)

   132                 distance = rep2;

   133               else

   134               {

   135                 distance = rep3;

   136                 rep3 = rep2;

   137               }

   138               rep2 = rep1;

   139             }

   140             rep1 = rep0;

   141             rep0 = distance;

   142           }

   143           if (len == 0)

   144           {

   145             len = _repMatchLenDecoder.Decode(&_rangeDecoder, posState) + kMatchMinLen;

   146             state.UpdateRep();

   147           }

   148         }

   149         else

   150         {

   151           rep3 = rep2;

   152           rep2 = rep1;

   153           rep1 = rep0;

   154           len = kMatchMinLen + _lenDecoder.Decode(&_rangeDecoder, posState);

   155           state.UpdateMatch();

   156           UInt32 posSlot = _posSlotDecoder[GetLenToPosState(len)].Decode(&_rangeDecoder);

   157           if (posSlot >= kStartPosModelIndex)

   158           {

   159             UInt32 numDirectBits = (posSlot >> 1) - 1;

   160             rep0 = ((2 | (posSlot & 1)) << numDirectBits);

   161 

   162             if (posSlot < kEndPosModelIndex)

   163               rep0 += NRangeCoder::ReverseBitTreeDecode(_posDecoders + 

   164                   rep0 - posSlot - 1, &_rangeDecoder, numDirectBits);

   165             else

   166             {

   167               rep0 += (_rangeDecoder.DecodeDirectBits(

   168                   numDirectBits - kNumAlignBits) << kNumAlignBits);

   169               rep0 += _posAlignDecoder.ReverseDecode(&_rangeDecoder);

   170               if (rep0 == 0xFFFFFFFF)

   171               {

   172                 _remainLen = kLenIdFinished;

   173                 return S_OK;

   174               }

   175             }

   176           }

   177           else

   178             rep0 = posSlot;

   179         }

   180         UInt32 locLen = len;

   181         if (len > curSize)

   182           locLen = (UInt32)curSize;

   183         if (!_outWindowStream.CopyBlock(rep0, locLen))

   184           return S_FALSE;

   185         previousByte = _outWindowStream.GetByte(0);

   186         curSize -= locLen;

   187         nowPos64 += locLen;

   188         len -= locLen;

   189         if (len != 0)

   190         {

   191           _remainLen = (Int32)len;

   192           break;

   193         }

   194 

   195         #ifdef _NO_EXCEPTIONS

   196         if (_outWindowStream.ErrorCode != S_OK)

   197           return _outWindowStream.ErrorCode;

   198         #endif

   199       }

   200     }

   201   }

   202   if (_rangeDecoder.Stream.WasFinished())

   203     return S_FALSE;

   204   _reps[0] = rep0;

   205   _reps[1] = rep1;

   206   _reps[2] = rep2;

   207   _reps[3] = rep3;

   208   _state = state;

   209 

   210   return S_OK;

   211 }

   212 

   213 STDMETHODIMP CDecoder::CodeReal(ISequentialInStream *inStream,

   214     ISequentialOutStream *outStream, 

   215     const UInt64 *, const UInt64 *outSize,

   216     ICompressProgressInfo *progress)

   217 {

   218   SetInStream(inStream);

   219   _outWindowStream.SetStream(outStream);

   220   SetOutStreamSize(outSize);

   221   CDecoderFlusher flusher(this);

   222 

   223   while (true)

   224   {

   225     UInt32 curSize = 1 << 18;

   226     RINOK(CodeSpec(curSize));

   227     if (_remainLen == kLenIdFinished)

   228       break;

   229     if (progress != NULL)

   230     {

   231       UInt64 inSize = _rangeDecoder.GetProcessedSize();

   232       UInt64 nowPos64 = _outWindowStream.GetProcessedSize();

   233       RINOK(progress->SetRatioInfo(&inSize, &nowPos64));

   234     }

   235     if (_outSizeDefined)

   236       if (_outWindowStream.GetProcessedSize() >= _outSize)

   237         break;

   238   } 

   239   flusher.NeedFlush = false;

   240   return Flush();

   241 }

   242 

   243 

   244 #ifdef _NO_EXCEPTIONS

   245 

   246 #define LZMA_TRY_BEGIN

   247 #define LZMA_TRY_END

   248 

   249 #else

   250 

   251 #define LZMA_TRY_BEGIN try { 

   252 #define LZMA_TRY_END } \

   253   catch(const CInBufferException &e)  { return e.ErrorCode; } \

   254   catch(const CLZOutWindowException &e)  { return e.ErrorCode; } \

   255   catch(...) { return S_FALSE; }

   256 

   257 #endif

   258 

   259 

   260 STDMETHODIMP CDecoder::Code(ISequentialInStream *inStream,

   261       ISequentialOutStream *outStream, const UInt64 *inSize, const UInt64 *outSize,

   262       ICompressProgressInfo *progress)

   263 {

   264   LZMA_TRY_BEGIN

   265   return CodeReal(inStream, outStream, inSize, outSize, progress); 

   266   LZMA_TRY_END

   267 }

   268 

   269 STDMETHODIMP CDecoder::SetDecoderProperties2(const Byte *properties, UInt32 size)

   270 {

   271   if (size < 5)

   272     return E_INVALIDARG;

   273   int lc = properties[0] % 9;

   274   Byte remainder = (Byte)(properties[0] / 9);

   275   int lp = remainder % 5;

   276   int pb = remainder / 5;

   277   if (pb > NLength::kNumPosStatesBitsMax)

   278     return E_INVALIDARG;

   279   _posStateMask = (1 << pb) - 1;

   280   UInt32 dictionarySize = 0;

   281   for (int i = 0; i < 4; i++)

   282     dictionarySize += ((UInt32)(properties[1 + i])) << (i * 8);

   283   if (!_outWindowStream.Create(dictionarySize))

   284     return E_OUTOFMEMORY;

   285   if (!_literalDecoder.Create(lp, lc))

   286     return E_OUTOFMEMORY;

   287   if (!_rangeDecoder.Create(1 << 20))

   288     return E_OUTOFMEMORY;

   289   return S_OK;

   290 }

   291 

   292 STDMETHODIMP CDecoder::GetInStreamProcessedSize(UInt64 *value)

   293 {

   294   *value = _rangeDecoder.GetProcessedSize();

   295   return S_OK;

   296 }

   297 

   298 STDMETHODIMP CDecoder::SetInStream(ISequentialInStream *inStream)

   299 {

   300   _rangeDecoder.SetStream(inStream);

   301   return S_OK;

   302 }

   303 

   304 STDMETHODIMP CDecoder::ReleaseInStream()

   305 {

   306   _rangeDecoder.ReleaseStream();

   307   return S_OK;

   308 }

   309 

   310 STDMETHODIMP CDecoder::SetOutStreamSize(const UInt64 *outSize)

   311 {

   312   if (_outSizeDefined = (outSize != NULL))

   313     _outSize = *outSize;

   314   _remainLen = kLenIdNeedInit;

   315   _outWindowStream.Init();

   316   return S_OK;

   317 }

   318 

   319 #ifdef _ST_MODE

   320 

   321 STDMETHODIMP CDecoder::Read(void *data, UInt32 size, UInt32 *processedSize)

   322 {

   323   LZMA_TRY_BEGIN

   324   if (processedSize)

   325     *processedSize = 0;

   326   const UInt64 startPos = _outWindowStream.GetProcessedSize();

   327   _outWindowStream.SetMemStream((Byte *)data);

   328   RINOK(CodeSpec(size));

   329   if (processedSize)

   330     *processedSize = (UInt32)(_outWindowStream.GetProcessedSize() - startPos);

   331   return Flush();

   332   LZMA_TRY_END

   333 }

   334 

   335 #endif

   336 

   337 }}

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