zipin.cpp

由7-zip提供的压缩、解压缩程序

      ThrowIncorrectArchiveException();
    */

    item.FileHeaderWithNameSize = 4 + 
        NFileHeader::kLocalBlockSize + fileNameSize;

    // IncreaseRealPosition(item.LocalExtraSize);
    if (item.LocalExtraSize > 0)
    {
      UInt64 localHeaderOffset = 0;
      UInt32 diskStartNumber = 0;
      CExtraBlock extraBlock;
      ReadExtra(item.LocalExtraSize, extraBlock, item.UnPackSize, item.PackSize, 
          localHeaderOffset, diskStartNumber);
    }

    if (item.HasDescriptor())
    {
      const int kBufferSize = (1 << 12);
      Byte buffer[kBufferSize];

      UInt32 numBytesInBuffer = 0;
      UInt32 packedSize = 0;

      bool descriptorWasFound = false;
      while (true)
      {
        UInt32 processedSize;
        RINOK(ReadBytes(buffer + numBytesInBuffer, 
            kBufferSize - numBytesInBuffer, &processedSize));
        numBytesInBuffer += processedSize;
        if (numBytesInBuffer < NFileHeader::kDataDescriptorSize)
          ThrowIncorrectArchiveException();
        UInt32 i;
        for (i = 0; i <= numBytesInBuffer - NFileHeader::kDataDescriptorSize; i++)
        {
          // descriptorSignature field is Info-ZIP's extension 
          // to Zip specification.
          UInt32 descriptorSignature = GetUInt32(buffer + i);

          // !!!! It must be fixed for Zip64 archives
          UInt32 descriptorPackSize = GetUInt32(buffer + i + 8);
          if (descriptorSignature== NSignature::kDataDescriptor &&
            descriptorPackSize == packedSize + i)
          {
            descriptorWasFound = true;
            item.FileCRC = GetUInt32(buffer + i + 4);
            item.PackSize = descriptorPackSize;
            item.UnPackSize = GetUInt32(buffer + i + 12);
            IncreaseRealPosition(Int64(Int32(0 - (numBytesInBuffer - i - 
                NFileHeader::kDataDescriptorSize))));
            break;
          };
        }
        if (descriptorWasFound)
          break;
        packedSize += i;
        int j;
        for (j = 0; i < numBytesInBuffer; i++, j++)
          buffer[j] = buffer[i];    
        numBytesInBuffer = j;
      }
    }
    else
      IncreaseRealPosition(item.PackSize);

    items.Add(item);
    if (progress != 0)
    {
      UInt64 numItems = items.Size();
      RINOK(progress->SetCompleted(&numItems));
    }
    if (!ReadUInt32(m_Signature))
      break;
  }
  UInt64 centralDirectorySize = 0;
  UInt64 centralDirectoryStartOffset = m_Position - 4;
  for(int i = 0; i < items.Size(); i++)
  {
    if (progress != 0)
    {
      UInt64 numItems = items.Size();
      RINOK(progress->SetCompleted(&numItems));
    }
    // if(m_Signature == NSignature::kEndOfCentralDir)
    //   break;
    if(m_Signature != NSignature::kCentralFileHeader)
      ThrowIncorrectArchiveException();
  
    // NFileHeader::CBlock header;
    // SafeReadBytes(&header, sizeof(header));

    Byte headerMadeByVersionVersion = ReadByte();
    Byte headerMadeByVersionHostOS = ReadByte();
    Byte centalHeaderExtractVersionVersion = ReadByte();
    Byte centalHeaderExtractVersionHostOS = ReadByte();
    UInt16 headerFlags = ReadUInt16() & NFileHeader::NFlags::kUsedBitsMask; 
    UInt16 headerCompressionMethod = ReadUInt16();
    UInt32 headerTime =  ReadUInt32();
    UInt32 headerFileCRC = ReadUInt32();
    UInt64 headerPackSize = ReadUInt32();
    UInt64 headerUnPackSize = ReadUInt32();
    UInt16 headerNameSize = ReadUInt16();
    UInt16 headerExtraSize = ReadUInt16();
    UInt16 headerCommentSize = ReadUInt16();
    UInt32 headerDiskNumberStart = ReadUInt16();
    UInt16 headerInternalAttributes = ReadUInt16();
    UInt32 headerExternalAttributes = ReadUInt32();
    UInt64 localHeaderOffset = ReadUInt32();
    AString centralName = ReadFileName(headerNameSize);
    
    // item.Name = ReadFileName(fileNameSize);

    CExtraBlock centralExtra;
    if (headerExtraSize > 0)
    {
      ReadExtra(headerExtraSize, centralExtra, headerUnPackSize, headerPackSize, localHeaderOffset, headerDiskNumberStart);
    }
    
    int index;
    int left = 0, right = items.Size();
    while(true)
    {
      if (left >= right)
        ThrowIncorrectArchiveException();
      index = (left + right) / 2;
      UInt64 position = items[index].LocalHeaderPosition;
      if (localHeaderOffset == position)
        break;
      if (localHeaderOffset < position)
        right = index;
      else
        left = index + 1;
    }
    CItemEx &item = items[index];
    item.MadeByVersion.Version = headerMadeByVersionVersion;
    item.MadeByVersion.HostOS = headerMadeByVersionHostOS;
    item.CentralExtra = centralExtra;

    if (
        // item.ExtractVersion != centalHeaderExtractVersion ||
        item.Flags != headerFlags ||
        item.CompressionMethod != headerCompressionMethod ||
        // item.Time != header.Time ||
        item.FileCRC != headerFileCRC)
      ThrowIncorrectArchiveException();

    if (item.Name.Length() != centralName.Length())
      ThrowIncorrectArchiveException(); // test it maybe better compare names
    item.Name = centralName;

    // item.CentralExtraPosition = m_Position;
    // item.CentralExtraSize = headerExtraSize;
    // item.CommentSize = headerCommentSize;
    if (headerDiskNumberStart != 0)
      throw CInArchiveException(CInArchiveException::kMultiVolumeArchiveAreNotSupported);
    item.InternalAttributes = headerInternalAttributes;
    item.ExternalAttributes = headerExternalAttributes;

    // May be these strings must be deleted
    if (item.IsDirectory())
    {
      // if (item.PackSize != 0 /*  || item.UnPackSize != 0 */)
      //   ThrowIncorrectArchiveException();
      item.UnPackSize = 0;
    }

    UInt32 currentRecordSize = 4 + NFileHeader::kCentralBlockSize + 
        headerNameSize + headerExtraSize + headerCommentSize;

    centralDirectorySize += currentRecordSize;

    // IncreaseRealPosition(headerExtraSize);

    if (
        item.PackSize != headerPackSize ||
        item.UnPackSize != headerUnPackSize
        )
      ThrowIncorrectArchiveException();

    // IncreaseRealPosition(headerCommentSize);
    ReadBuffer(item.Comment, headerCommentSize);

    if (!ReadUInt32(m_Signature))
      break;
  }
  UInt32 thisDiskNumber = 0;
  UInt32 startCDDiskNumber = 0;
  UInt64 numEntriesInCDOnThisDisk = 0;
  UInt64 numEntriesInCD = 0;
  UInt64 cdSize = 0;
  UInt64 cdStartOffsetFromRecord = 0;
  bool isZip64 = false;
  UInt64 zip64EndOfCDStartOffset = m_Position - 4;
  if(m_Signature == NSignature::kZip64EndOfCentralDir)
  {
    isZip64 = true;
    UInt64 recordSize = ReadUInt64();
    UInt16 versionMade = ReadUInt16();
    UInt16 versionNeedExtract = ReadUInt16();
    thisDiskNumber = ReadUInt32();
    startCDDiskNumber = ReadUInt32();
    numEntriesInCDOnThisDisk = ReadUInt64();
    numEntriesInCD = ReadUInt64();
    cdSize = ReadUInt64();
    cdStartOffsetFromRecord = ReadUInt64();
    IncreaseRealPosition(recordSize - kZip64EndOfCentralDirRecordSize);
    if (!ReadUInt32(m_Signature))
      return S_FALSE;
    if (thisDiskNumber != 0 || startCDDiskNumber != 0)
      throw CInArchiveException(CInArchiveException::kMultiVolumeArchiveAreNotSupported);
    if (numEntriesInCDOnThisDisk != items.Size() ||
        numEntriesInCD != items.Size() ||
        cdSize != centralDirectorySize ||
        (cdStartOffsetFromRecord != centralDirectoryStartOffset &&
        (!items.IsEmpty())))
      ThrowIncorrectArchiveException();
  }
  if(m_Signature == NSignature::kZip64EndOfCentralDirLocator)
  {
    UInt32 startEndCDDiskNumber = ReadUInt32();
    UInt64 endCDStartOffset = ReadUInt64();
    UInt32 numberOfDisks = ReadUInt32();
    if (zip64EndOfCDStartOffset != endCDStartOffset)
      ThrowIncorrectArchiveException();
    if (!ReadUInt32(m_Signature))
      return S_FALSE;
  }
  if(m_Signature != NSignature::kEndOfCentralDir)
    ThrowIncorrectArchiveException();

  UInt16 thisDiskNumber16 = ReadUInt16();
  if (!isZip64 || thisDiskNumber16)
    thisDiskNumber = thisDiskNumber16;

  UInt16 startCDDiskNumber16 = ReadUInt16();
  if (!isZip64 || startCDDiskNumber16 != 0xFFFF)
    startCDDiskNumber = startCDDiskNumber16;

  UInt16 numEntriesInCDOnThisDisk16 = ReadUInt16();
  if (!isZip64 || numEntriesInCDOnThisDisk16 != 0xFFFF)
    numEntriesInCDOnThisDisk = numEntriesInCDOnThisDisk16;

  UInt16 numEntriesInCD16 = ReadUInt16();
  if (!isZip64 || numEntriesInCD16 != 0xFFFF)
    numEntriesInCD = numEntriesInCD16;

  UInt32 cdSize32 = ReadUInt32();
  if (!isZip64 || cdSize32 != 0xFFFFFFFF)
    cdSize = cdSize32;

  UInt32 cdStartOffsetFromRecord32 = ReadUInt32();
  if (!isZip64 || cdStartOffsetFromRecord32 != 0xFFFFFFFF)
    cdStartOffsetFromRecord = cdStartOffsetFromRecord32;

  UInt16 commentSize = ReadUInt16();
  ReadBuffer(m_ArchiveInfo.Comment, commentSize);
  
  if (thisDiskNumber != 0 || startCDDiskNumber != 0)
    throw CInArchiveException(CInArchiveException::kMultiVolumeArchiveAreNotSupported);
  if ((UInt16)numEntriesInCDOnThisDisk != ((UInt16)items.Size()) ||
      (UInt16)numEntriesInCD != ((UInt16)items.Size()) ||
      (UInt32)cdSize != (UInt32)centralDirectorySize ||
      ((UInt32)(cdStartOffsetFromRecord) != (UInt32)centralDirectoryStartOffset &&
        (!items.IsEmpty())))
    ThrowIncorrectArchiveException();
  
  return S_OK;
}

ISequentialInStream* CInArchive::CreateLimitedStream(UInt64 position, UInt64 size)
{
  CLimitedSequentialInStream *streamSpec = new CLimitedSequentialInStream;
  CMyComPtr<ISequentialInStream> inStream(streamSpec);
  SeekInArchive(position);
  streamSpec->Init(m_Stream, size);
  return inStream.Detach();
}

IInStream* CInArchive::CreateStream()
{
  CMyComPtr<IInStream> inStream = m_Stream;
  return inStream.Detach();
}

bool CInArchive::SeekInArchive(UInt64 position)
{
  UInt64 newPosition;
  if(m_Stream->Seek(position, STREAM_SEEK_SET, &newPosition) != S_OK)
    return false;
  return (newPosition == position);
}

}}