ziphandlerout.cpp

7z一个高压缩比的压缩程序源代码,重要的是里面的算法值得学习

    CMyComBSTR password;
    Int32 passwordIsDefined;
    RINOK(getTextPassword->CryptoGetTextPassword2(&passwordIsDefined, &password));
    options.PasswordIsDefined = IntToBool(passwordIsDefined);
    if (options.PasswordIsDefined)
    {
      options.IsAesMode = (m_ForceAesMode ? m_IsAesMode : thereAreAesUpdates);
      options.AesKeyMode = m_AesKeyMode;

      if (!IsAsciiString((const wchar_t *)password))
        return E_INVALIDARG;
      if (options.IsAesMode)
      {
        if (options.Password.Length() > NCrypto::NWzAes::kPasswordSizeMax)
          return E_INVALIDARG;
      }
      options.Password = UnicodeStringToMultiByte((const wchar_t *)password, CP_OEMCP);
    }
  }
  else
    options.PasswordIsDefined = false;

  int level = m_Level;
  if (level < 0)
    level = 5;
  
  Byte mainMethod;
  if (m_MainMethod < 0)
    mainMethod = (Byte)(((level == 0) ?
        NFileHeader::NCompressionMethod::kStored :
        NFileHeader::NCompressionMethod::kDeflated));
  else
    mainMethod = (Byte)m_MainMethod;
  options.MethodSequence.Add(mainMethod);
  if (mainMethod != NFileHeader::NCompressionMethod::kStored)
    options.MethodSequence.Add(NFileHeader::NCompressionMethod::kStored);
  bool isDeflate = (mainMethod == NFileHeader::NCompressionMethod::kDeflated) ||
      (mainMethod == NFileHeader::NCompressionMethod::kDeflated64);
  bool isLZMA = (mainMethod == NFileHeader::NCompressionMethod::kLZMA);
  bool isLz = (isLZMA || isDeflate);
  bool isBZip2 = (mainMethod == NFileHeader::NCompressionMethod::kBZip2);
  options.NumPasses = m_NumPasses;
  options.DicSize = m_DicSize;
  options.NumFastBytes = m_NumFastBytes;
  options.NumMatchFinderCycles = m_NumMatchFinderCycles;
  options.NumMatchFinderCyclesDefined = m_NumMatchFinderCyclesDefined;
  options.Algo = m_Algo;
  #ifdef COMPRESS_MT
  options.NumThreads = _numThreads;
  #endif
  if (isLz)
  {
    if (isDeflate)
    {
      if (options.NumPasses == 0xFFFFFFFF)
        options.NumPasses = (level >= 9 ? kDeflateNumPassesX9 :
                            (level >= 7 ? kDeflateNumPassesX7 :
                                          kDeflateNumPassesX1));
      if (options.NumFastBytes == 0xFFFFFFFF)
        options.NumFastBytes = (level >= 9 ? kDeflateNumFastBytesX9 :
                               (level >= 7 ? kDeflateNumFastBytesX7 :
                                             kDeflateNumFastBytesX1));
    }
    else if (isLZMA)
    {
      if (options.DicSize == 0xFFFFFFFF)
        options.DicSize =
          (level >= 9 ? kLzmaDicSizeX9 :
          (level >= 7 ? kLzmaDicSizeX7 :
          (level >= 5 ? kLzmaDicSizeX5 :
          (level >= 3 ? kLzmaDicSizeX3 :
                        kLzmaDicSizeX1))));

      if (options.NumFastBytes == 0xFFFFFFFF)
        options.NumFastBytes = (level >= 7 ? kLzmaNumFastBytesX7 :
                                             kLzmaNumFastBytesX1);

      options.MatchFinder =
        (level >= 5 ? kLzmaMatchFinderX5 :
                      kLzmaMatchFinderX1);
    }

    if (options.Algo == 0xFFFFFFFF)
        options.Algo = (level >= 5 ? kLzAlgoX5 :
                                     kLzAlgoX1);
  }
  if (isBZip2)
  {
    if (options.NumPasses == 0xFFFFFFFF)
      options.NumPasses = (level >= 9 ? kBZip2NumPassesX9 :
                          (level >= 7 ? kBZip2NumPassesX7 :
                                        kBZip2NumPassesX1));
    if (options.DicSize == 0xFFFFFFFF)
      options.DicSize = (level >= 5 ? kBZip2DicSizeX5 :
                        (level >= 3 ? kBZip2DicSizeX3 :
                                      kBZip2DicSizeX1));
  }

  return Update(
      EXTERNAL_CODECS_VARS
      m_Items, updateItems, outStream,
      m_Archive.IsOpen() ? &m_Archive : NULL, &options, callback);
  COM_TRY_END2
}

STDMETHODIMP CHandler::SetProperties(const wchar_t **names, const PROPVARIANT *values, Int32 numProperties)
{
  #ifdef COMPRESS_MT
  const UInt32 numProcessors = NSystem::GetNumberOfProcessors();
  _numThreads = numProcessors;
  #endif
  InitMethodProperties();
  for (int i = 0; i < numProperties; i++)
  {
    UString name = UString(names[i]);
    name.MakeUpper();
    if (name.IsEmpty())
      return E_INVALIDARG;

    const PROPVARIANT &prop = values[i];

    if (name[0] == L'X')
    {
      UInt32 level = 9;
      RINOK(ParsePropValue(name.Mid(1), prop, level));
      m_Level = level;
      continue;
    }
    else if (name == L"M")
    {
      if (prop.vt == VT_BSTR)
      {
        UString m = prop.bstrVal;
        m.MakeUpper();
        if (m == L"COPY") m_MainMethod = NFileHeader::NCompressionMethod::kStored;
        else if (m == L"DEFLATE") m_MainMethod = NFileHeader::NCompressionMethod::kDeflated;
        else if (m == L"DEFLATE64") m_MainMethod = NFileHeader::NCompressionMethod::kDeflated64;
        else if (m == L"BZIP2") m_MainMethod = NFileHeader::NCompressionMethod::kBZip2;
        else if (m == L"LZMA") m_MainMethod = NFileHeader::NCompressionMethod::kLZMA;
        else return E_INVALIDARG;
      }
      else if (prop.vt == VT_UI4)
      {
        switch(prop.ulVal)
        {
          case NFileHeader::NCompressionMethod::kStored:
          case NFileHeader::NCompressionMethod::kDeflated:
          case NFileHeader::NCompressionMethod::kDeflated64:
          case NFileHeader::NCompressionMethod::kBZip2:
          case NFileHeader::NCompressionMethod::kLZMA:
            m_MainMethod = (Byte)prop.ulVal;
            break;
          default:
            return E_INVALIDARG;
        }
      }
      else
        return E_INVALIDARG;
    }
    else if (name.Left(2) == L"EM")
    {
      if (prop.vt == VT_BSTR)
      {
        UString valueString = prop.bstrVal;
        valueString.MakeUpper();
        if (valueString.Left(3) == L"AES")
        {
          valueString = valueString.Mid(3);
          if (valueString == L"128")
            m_AesKeyMode = 1;
          else if (valueString == L"192")
            m_AesKeyMode = 2;
          else if (valueString == L"256" || valueString.IsEmpty())
            m_AesKeyMode = 3;
          else
            return E_INVALIDARG;
          m_IsAesMode = true;
          m_ForceAesMode = true;
        }
        else if (valueString == L"ZIPCRYPTO")
        {
          m_IsAesMode = false;
          m_ForceAesMode = true;
        }
        else
          return E_INVALIDARG;
      }
      else
        return E_INVALIDARG;
    }
    else if (name[0] == L'D')
    {
      UInt32 dicSize = kBZip2DicSizeX5;
      RINOK(ParsePropDictionaryValue(name.Mid(1), prop, dicSize));
      m_DicSize = dicSize;
    }
    else if (name.Left(4) == L"PASS")
    {
      UInt32 num = kDeflateNumPassesX9;
      RINOK(ParsePropValue(name.Mid(4), prop, num));
      m_NumPasses = num;
    }
    else if (name.Left(2) == L"FB")
    {
      UInt32 num = kDeflateNumFastBytesX9;
      RINOK(ParsePropValue(name.Mid(2), prop, num));
      m_NumFastBytes = num;
    }
    else if (name.Left(2) == L"MC")
    {
      UInt32 num = 0xFFFFFFFF;
      RINOK(ParsePropValue(name.Mid(2), prop, num));
      m_NumMatchFinderCycles = num;
      m_NumMatchFinderCyclesDefined = true;
    }
    else if (name.Left(2) == L"MT")
    {
      #ifdef COMPRESS_MT
      RINOK(ParseMtProp(name.Mid(2), prop, numProcessors, _numThreads));
      #endif
    }
    else if (name.Left(1) == L"A")
    {
      UInt32 num = kLzAlgoX5;
      RINOK(ParsePropValue(name.Mid(1), prop, num));
      m_Algo = num;
    }
    else if (name.CompareNoCase(L"TC") == 0)
    {
      RINOK(SetBoolProperty(m_WriteNtfsTimeExtra, prop));
    }
    else if (name.CompareNoCase(L"CL") == 0)
    {
      RINOK(SetBoolProperty(m_ForseLocal, prop));
      if (m_ForseLocal)
        m_ForseUtf8 = false;
    }
    else if (name.CompareNoCase(L"CU") == 0)
    {
      RINOK(SetBoolProperty(m_ForseUtf8, prop));
      if (m_ForseUtf8)
        m_ForseLocal = false;
    }
    else
      return E_INVALIDARG;
  }
  return S_OK;
}

}}