chmhandler.cpp

7-Zip 是一款号称有着现今最高压缩比的压缩软件

        m_PosInFolder += numBytesToWrite;
      }
      if (fileOffset == m_PosInSection)
      {
        RINOK(OpenFile());
        m_FileIsOpen = true;
        m_CurrentIndex++;
        m_IsOk = true;
      }
    }
  }
  return WriteEmptyFiles();
}

STDMETHODIMP CChmFolderOutStream::Write(const void *data, UInt32 size, UInt32 *processedSize)
{
  return Write2(data, size, processedSize, true);
}

HRESULT CChmFolderOutStream::FlushCorrupted(UInt64 maxSize)
{
  const UInt32 kBufferSize = (1 << 10);
  Byte buffer[kBufferSize];
  for (int i = 0; i < kBufferSize; i++)
    buffer[i] = 0;
  if (maxSize > m_FolderSize)
    maxSize = m_FolderSize;
  while (m_PosInFolder < maxSize)
  {
    UInt32 size = (UInt32)MyMin(maxSize - m_PosInFolder, (UInt64)kBufferSize);
    UInt32 processedSizeLocal = 0;
    RINOK(Write2(buffer, size, &processedSizeLocal, false));
    if (processedSizeLocal == 0)
      return S_OK;
  }
  return S_OK;
}


STDMETHODIMP CHandler::Extract(const UInt32* indices, UInt32 numItems,
    Int32 _aTestMode, IArchiveExtractCallback *extractCallback)
{
  COM_TRY_BEGIN
  bool allFilesMode = (numItems == UInt32(-1));

  if (allFilesMode)
    numItems = m_Database.NewFormat ? 1:
      (m_Database.LowLevel ?
      m_Database.Items.Size():
      m_Database.Indices.Size());
  if (numItems == 0)
    return S_OK;
  bool testMode = (_aTestMode != 0);

  UInt64 currentTotalSize = 0;

  NCompress::CCopyCoder *copyCoderSpec = new NCompress::CCopyCoder();
  CMyComPtr<ICompressCoder> copyCoder = copyCoderSpec;
  UInt32 i;

  CLocalProgress *lps = new CLocalProgress;
  CMyComPtr<ICompressProgressInfo> progress = lps;
  lps->Init(extractCallback, false);

  CLimitedSequentialInStream *streamSpec = new CLimitedSequentialInStream;
  CMyComPtr<ISequentialInStream> inStream(streamSpec);
  streamSpec->SetStream(m_Stream);

  if (m_Database.LowLevel)
  {
    UInt64 currentItemSize = 0;
    UInt64 totalSize = 0;
    if (m_Database.NewFormat)
      totalSize = m_Database.NewFormatString.Length();
    else
      for (i = 0; i < numItems; i++)
        totalSize += m_Database.Items[allFilesMode ? i : indices[i]].Size;
    extractCallback->SetTotal(totalSize);
    
    for (i = 0; i < numItems; i++, currentTotalSize += currentItemSize)
    {
      currentItemSize = 0;
      lps->InSize = currentTotalSize; // Change it
      lps->OutSize = currentTotalSize;

      RINOK(lps->SetCur());
      CMyComPtr<ISequentialOutStream> realOutStream;
      Int32 askMode= testMode ?
          NArchive::NExtract::NAskMode::kTest :
          NArchive::NExtract::NAskMode::kExtract;
      Int32 index = allFilesMode ? i : indices[i];
      RINOK(extractCallback->GetStream(index, &realOutStream, askMode));

      if (m_Database.NewFormat)
      {
        if (index != 0)
          return E_FAIL;
        if (!testMode && (!realOutStream))
          continue;
        if (!testMode)
        {
          UInt32 size = m_Database.NewFormatString.Length();
          RINOK(WriteStream(realOutStream, (const char *)m_Database.NewFormatString, size));
        }
        RINOK(extractCallback->SetOperationResult(NArchive::NExtract::NOperationResult::kOK));
        continue;
      }
      const CItem &item = m_Database.Items[index];
      
      currentItemSize = item.Size;
      
      if (!testMode && (!realOutStream))
        continue;
      RINOK(extractCallback->PrepareOperation(askMode));
      if (item.Section != 0)
      {
        RINOK(extractCallback->SetOperationResult(NArchive::NExtract::NOperationResult::kUnSupportedMethod));
        continue;
      }

      if (testMode)
      {
        RINOK(extractCallback->SetOperationResult(NArchive::NExtract::NOperationResult::kOK));
        continue;
      }
      
      RINOK(m_Stream->Seek(m_Database.ContentOffset + item.Offset, STREAM_SEEK_SET, NULL));
      streamSpec->Init(item.Size);
      
      RINOK(copyCoder->Code(inStream, realOutStream, NULL, NULL, progress));
      realOutStream.Release();
      RINOK(extractCallback->SetOperationResult((copyCoderSpec->TotalSize == item.Size) ?
          NArchive::NExtract::NOperationResult::kOK:
          NArchive::NExtract::NOperationResult::kDataError));
    }
    return S_OK;
  }
  
  UInt64 lastFolderIndex = ((UInt64)0 - 1);
  for (i = 0; i < numItems; i++)
  {
    UInt32 index = allFilesMode ? i : indices[i];
    int entryIndex = m_Database.Indices[index];
    const CItem &item = m_Database.Items[entryIndex];
    UInt64 sectionIndex = item.Section;
    if (item.IsDir() || item.Size == 0)
      continue;
    if (sectionIndex == 0)
    {
      currentTotalSize += item.Size;
      continue;
    }
    const CSectionInfo &section = m_Database.Sections[(int)item.Section];
    if (section.IsLzx())
    {
      const CLzxInfo &lzxInfo = section.Methods[0].LzxInfo;
      UInt64 folderIndex = m_Database.GetFolder(index);
      if (lastFolderIndex == folderIndex)
        folderIndex++;
      lastFolderIndex = m_Database.GetLastFolder(index);
      for (; folderIndex <= lastFolderIndex; folderIndex++)
        currentTotalSize += lzxInfo.GetFolderSize();
    }
  }

  RINOK(extractCallback->SetTotal(currentTotalSize));

  NCompress::NLzx::CDecoder *lzxDecoderSpec = 0;
  CMyComPtr<ICompressCoder> lzxDecoder;
  CChmFolderOutStream *chmFolderOutStream = 0;
  CMyComPtr<ISequentialOutStream> outStream;

  currentTotalSize = 0;

  CRecordVector<bool> extractStatuses;
  for (i = 0; i < numItems;)
  {
    RINOK(extractCallback->SetCompleted(&currentTotalSize));
    UInt32 index = allFilesMode ? i : indices[i];
    i++;
    int entryIndex = m_Database.Indices[index];
    const CItem &item = m_Database.Items[entryIndex];
    UInt64 sectionIndex = item.Section;
    Int32 askMode= testMode ?
        NArchive::NExtract::NAskMode::kTest :
        NArchive::NExtract::NAskMode::kExtract;
    if (item.IsDir())
    {
      CMyComPtr<ISequentialOutStream> realOutStream;
      RINOK(extractCallback->GetStream(index, &realOutStream, askMode));
      RINOK(extractCallback->PrepareOperation(askMode));
      realOutStream.Release();
      RINOK(extractCallback->SetOperationResult(NArchive::NExtract::NOperationResult::kOK));
      continue;
    }

    lps->InSize = currentTotalSize; // Change it
    lps->OutSize = currentTotalSize;

    if (item.Size == 0 || sectionIndex == 0)
    {
      CMyComPtr<ISequentialOutStream> realOutStream;
      RINOK(extractCallback->GetStream(index, &realOutStream, askMode));
      if (!testMode && (!realOutStream))
        continue;
      RINOK(extractCallback->PrepareOperation(askMode));
      Int32 opRes = NArchive::NExtract::NOperationResult::kOK;
      if (!testMode && item.Size != 0)
      {
        RINOK(m_Stream->Seek(m_Database.ContentOffset + item.Offset, STREAM_SEEK_SET, NULL));
        streamSpec->Init(item.Size);
        RINOK(copyCoder->Code(inStream, realOutStream, NULL, NULL, progress));
        if (copyCoderSpec->TotalSize != item.Size)
          opRes = NArchive::NExtract::NOperationResult::kDataError;
      }
      realOutStream.Release();
      RINOK(extractCallback->SetOperationResult(opRes));
      currentTotalSize += item.Size;
      continue;
    }
  
    const CSectionInfo &section = m_Database.Sections[(int)sectionIndex];

    if (!section.IsLzx())
    {
      CMyComPtr<ISequentialOutStream> realOutStream;
      RINOK(extractCallback->GetStream(index, &realOutStream, askMode));
      if(!testMode && (!realOutStream))
        continue;
      RINOK(extractCallback->PrepareOperation(askMode));
      RINOK(extractCallback->SetOperationResult(NArchive::NExtract::NOperationResult::kUnSupportedMethod));
      continue;
    }

    const CLzxInfo &lzxInfo = section.Methods[0].LzxInfo;

    if (chmFolderOutStream == 0)
    {
      chmFolderOutStream = new CChmFolderOutStream;
      outStream = chmFolderOutStream;
    }

    chmFolderOutStream->Init(&m_Database, extractCallback, testMode);

    if(lzxDecoderSpec == NULL)
    {
      lzxDecoderSpec = new NCompress::NLzx::CDecoder;
      lzxDecoder = lzxDecoderSpec;
    }

    UInt64 folderIndex = m_Database.GetFolder(index);

    UInt64 compressedPos = m_Database.ContentOffset + section.Offset;
    UInt32 numDictBits = lzxInfo.GetNumDictBits();
    RINOK(lzxDecoderSpec->SetParams(numDictBits));

    const CItem *lastItem = &item;
    extractStatuses.Clear();
    extractStatuses.Add(true);

    for (;; folderIndex++)
    {
      RINOK(extractCallback->SetCompleted(&currentTotalSize));

      UInt64 startPos = lzxInfo.GetFolderPos(folderIndex);
      UInt64 finishPos = lastItem->Offset + lastItem->Size;
      UInt64 limitFolderIndex = lzxInfo.GetFolder(finishPos);

      lastFolderIndex = m_Database.GetLastFolder(index);
      UInt64 folderSize = lzxInfo.GetFolderSize();
      UInt64 unPackSize = folderSize;
      if (extractStatuses.IsEmpty())
        chmFolderOutStream->m_StartIndex = index + 1;
      else
        chmFolderOutStream->m_StartIndex = index;
      if (limitFolderIndex == folderIndex)
      {
        for (; i < numItems; i++)
        {
          UInt32 nextIndex = allFilesMode ? i : indices[i];
          int entryIndex = m_Database.Indices[nextIndex];
          const CItem &nextItem = m_Database.Items[entryIndex];
          if (nextItem.Section != sectionIndex)
            break;
          UInt64 nextFolderIndex = m_Database.GetFolder(nextIndex);
          if (nextFolderIndex != folderIndex)
            break;
          for (index++; index < nextIndex; index++)
            extractStatuses.Add(false);
          extractStatuses.Add(true);
          index = nextIndex;
          lastItem = &nextItem;
          if (nextItem.Size != 0)
            finishPos = nextItem.Offset + nextItem.Size;
          lastFolderIndex = m_Database.GetLastFolder(index);
        }
      }
      unPackSize = MyMin(finishPos - startPos, unPackSize);

      chmFolderOutStream->m_FolderSize = folderSize;
      chmFolderOutStream->m_PosInFolder = 0;
      chmFolderOutStream->m_PosInSection = startPos;
      chmFolderOutStream->m_ExtractStatuses = &extractStatuses;
      chmFolderOutStream->m_NumFiles = extractStatuses.Size();
      chmFolderOutStream->m_CurrentIndex = 0;
      try
      {
        UInt64 startBlock = lzxInfo.GetBlockIndexFromFolderIndex(folderIndex);
        const CResetTable &rt = lzxInfo.ResetTable;
        UInt32 numBlocks = (UInt32)rt.GetNumBlocks(unPackSize);
        for (UInt32 b = 0; b < numBlocks; b++)
        {
          UInt64 completedSize = currentTotalSize + chmFolderOutStream->m_PosInSection - startPos;
          RINOK(extractCallback->SetCompleted(&completedSize));
          UInt64 bCur = startBlock + b;
          if (bCur >= rt.ResetOffsets.Size())
            return E_FAIL;
          UInt64 offset = rt.ResetOffsets[(int)bCur];
          UInt64 compressedSize;
          rt.GetCompressedSizeOfBlock(bCur, compressedSize);
          UInt64 rem = finishPos - chmFolderOutStream->m_PosInSection;
          if (rem > rt.BlockSize)
            rem = rt.BlockSize;
          RINOK(m_Stream->Seek(compressedPos + offset, STREAM_SEEK_SET, NULL));
          streamSpec->SetStream(m_Stream);
          streamSpec->Init(compressedSize);
          lzxDecoderSpec->SetKeepHistory(b > 0);
          HRESULT res = lzxDecoder->Code(inStream, outStream, NULL, &rem, NULL);
          if (res != S_OK)
          {
            if (res != S_FALSE)
              return res;
            throw 1;
          }
        }
      }
      catch(...)
      {
        RINOK(chmFolderOutStream->FlushCorrupted(unPackSize));
      }
      currentTotalSize += folderSize;
      if (folderIndex == lastFolderIndex)
        break;
      extractStatuses.Clear();
    }
  }
  return S_OK;
  COM_TRY_END
}

STDMETHODIMP CHandler::GetNumberOfItems(UInt32 *numItems)
{
    *numItems = m_Database.NewFormat ? 1:
      (m_Database.LowLevel ?
      m_Database.Items.Size():
      m_Database.Indices.Size());
  return S_OK;
}

}}