itkVTIImageIO.h

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/*=========================================================================
 *
 *  Copyright NumFOCUS
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *         https://www.apache.org/licenses/LICENSE-2.0.txt
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *=========================================================================*/
#ifndef itkVTIImageIO_h
#define itkVTIImageIO_h
#include "ITKIOVTKExport.h"
 
#include <fstream>
#include "itkImageIOBase.h"
 
namespace itk
{
class ITKIOVTK_EXPORT VTIImageIO : public ImageIOBase
{
public:
  ITK_DISALLOW_COPY_AND_MOVE(VTIImageIO);

  using Self = VTIImageIO;
  using Superclass = ImageIOBase;
  using Pointer = SmartPointer<Self>;
  using ConstPointer = SmartPointer<const Self>;

  itkNewMacro(Self);

  itkOverrideGetNameOfClassMacro(VTIImageIO);
 
  /*-------- This part of the interface deals with reading data. ------ */

  bool
  CanReadFile(const char *) override;

  void
  ReadImageInformation() override;

  void
  Read(void * buffer) override;
 
  /*-------- This part of the interfaces deals with writing data. ----- */

  bool
  CanWriteFile(const char *) override;

  void
  WriteImageInformation() override
  {}

  void
  Write(const void * buffer) override;

  static void
  SwapBufferForByteOrder(void *          buffer,
                         std::size_t     componentSize,
                         std::size_t     numComponents,
                         IOByteOrderEnum fileByteOrder,
                         IOByteOrderEnum targetByteOrder);
 
protected:
  VTIImageIO();
  ~VTIImageIO() override;
 
  void
  PrintSelf(std::ostream & os, Indent indent) const override;
 
private:
  static IOComponentEnum
  VTKTypeStringToITKComponent(const std::string & vtkType);

  static std::string
  ITKComponentToVTKTypeString(IOComponentEnum t);

  static SizeType
  DecodeBase64(const std::string & encoded, std::vector<unsigned char> & decoded);

  static std::string
  EncodeBase64(const unsigned char * data, SizeType numBytes);

  static std::string
  TrimString(const std::string & s);
 
  // Encoding format of the data array found in the file.
  // (Plain comment, not doxygen, to satisfy KWStyle's `\class` rule for
  // class-like declarations.)
  enum class DataEncoding : std::uint8_t
  {
    ASCII,
    Base64,            // binary data encoded in base64 (format="binary")
    RawAppended,       // raw binary appended data (format="appended" with encoding="raw")
    Base64Appended,    // base64-encoded appended data (format="appended" with encoding="base64")
    ZLibBase64,        // zlib-compressed data encoded in base64 (inline)
    ZLibAppended,      // zlib-compressed raw appended data
    ZLibBase64Appended // zlib-compressed base64 appended data
  };
 
  DataEncoding m_DataEncoding{ DataEncoding::Base64 };

  std::string m_AsciiDataContent{};

  std::string m_Base64DataContent{};

  std::streampos m_AppendedDataOffset{ 0 };

  SizeType m_DataArrayOffset{ 0 };

  bool m_HeaderTypeUInt64{ false };

  bool m_IsZLibCompressed{ false };

  bool m_AppendedDataIsBase64{ false };

  std::string m_AppendedBase64Content{};

  static void
  DecompressZLib(const unsigned char *        compressedData,
                 std::size_t                  compressedDataSize,
                 bool                         headerUInt64,
                 std::vector<unsigned char> & uncompressed);
};
} // end namespace itk
 
#endif // itkVTIImageIO_h