ConversionIO.h

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// # ConversionIO.h: Class for IO in a converted format
// # Copyright (C) 1996,1999,2001
// # Associated Universities, Inc. Washington DC, USA.
// #
// # This library is free software; you can redistribute it and/or modify it
// # under the terms of the GNU Library General Public License as published by
// # the Free Software Foundation; either version 2 of the License, or (at your
// # option) any later version.
// #
// # This library is distributed in the hope that it will be useful, but WITHOUT
// # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// # FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
// # License for more details.
// #
// # You should have received a copy of the GNU Library General Public License
// # along with this library; if not, write to the Free Software Foundation,
// # Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
// #
// # Correspondence concerning AIPS++ should be addressed as follows:
// #        Internet email: casa-feedback@nrao.edu.
// #        Postal address: AIPS++ Project Office
// #                        National Radio Astronomy Observatory
// #                        520 Edgemont Road
// #                        Charlottesville, VA 22903-2475 USA
 
#ifndef CASA_CONVERSIONIO_H
#define CASA_CONVERSIONIO_H
 
#include <casacore/casa/aips.h>
#include <casacore/casa/IO/TypeIO.h>
#include <memory>
// # The following should be a declaration. But our Complex & DComplex classes
// # are a typedef hence this does not work. Replace the following with
// # forward declarations when Complex and DComplex are no longer typedefs.
#include <casacore/casa/BasicSL/Complex.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
class DataConversion;
class ByteIO;
class String;
 
// <summary>Class for IO in a converted format.</summary>
 
// <use visibility=export>
 
// <reviewed reviewer="Friso Olnon" date="1996/11/06" tests="tTypeIO" demos="">
// </reviewed>
 
// <prerequisite>
//    <li> <linkto class=ByteIO>ByteIO</linkto> class and derived classes
//    <li> <linkto class=TypeIO>TypeIO</linkto>class
//    <li> <linkto class=DataConversion>DataConversion</linkto>
// </prerequisite>
 
// <synopsis>
// ConversionIO is a specialization of class TypeIO to store
// data in a converted format.
// <p>
// The class converts the data to/from external data and reads/writes
// them from/into the ByteIO object given at construction time.
// Conversion is only done when really needed. If not needed, the
// data is directly read or written.
// <p>
// This class is useful when data can be stored in one of multiple formats.
// Only at construction time the correct <linkto class=DataConversion>
// DataConversion</linkto> class has to be given. Thereafter polymorphism
// ensures that the correct conversion is done when reading or writing.
// </synopsis>
 
class ConversionIO : public TypeIO {
 public:
  // Constructor.
  // The read/write functions will use the given <src>ByteIO</src> object
  // as the data store and the given <src>DataConversion</src> object
  // as the conversion engine.
  // <p>
  // The read and write functions use an intermediate buffer to hold the data
  // in canonical format.  For small arrays it uses a fixed buffer with
  // length <src>bufferLength</src>. For arrays not fitting in this buffer,
  // it uses a temporary buffer allocated on the heap.
  ConversionIO(const std::shared_ptr<DataConversion>& dataConversion,
               const std::shared_ptr<ByteIO>& byteIO, uInt bufferLength = 4096);
 
  // The copy constructor uses reference semantics
  ConversionIO(const ConversionIO& conversionIO);
 
  // The assignment operator uses reference semantics
  ConversionIO& operator=(const ConversionIO& conversionIO);
 
  // Destructor, deletes allocated memory.
  ~ConversionIO();
 
  // Convert the values and write them to the ByteIO object.
  // Bool, complex and String values are handled by the base class.
  // <group>
  virtual size_t write(size_t nvalues, const Bool* value);
  virtual size_t write(size_t nvalues, const Char* data);
  virtual size_t write(size_t nvalues, const uChar* data);
  virtual size_t write(size_t nvalues, const Short* data);
  virtual size_t write(size_t nvalues, const uShort* data);
  virtual size_t write(size_t nvalues, const Int* data);
  virtual size_t write(size_t nvalues, const uInt* data);
  virtual size_t write(size_t nvalues, const Int64* data);
  virtual size_t write(size_t nvalues, const uInt64* data);
  virtual size_t write(size_t nvalues, const Float* data);
  virtual size_t write(size_t nvalues, const Double* data);
  virtual size_t write(size_t nvalues, const Complex* value);
  virtual size_t write(size_t nvalues, const DComplex* value);
  virtual size_t write(size_t nvalues, const String* value);
  // </group>
 
  // Read the values from the ByteIO object and convert them.
  // Bool, complex and String values are handled by the base class.
  // <group>
  virtual size_t read(size_t nvalues, Bool* value);
  virtual size_t read(size_t nvalues, Char* data);
  virtual size_t read(size_t nvalues, uChar* data);
  virtual size_t read(size_t nvalues, Short* data);
  virtual size_t read(size_t nvalues, uShort* data);
  virtual size_t read(size_t nvalues, Int* data);
  virtual size_t read(size_t nvalues, uInt* data);
  virtual size_t read(size_t nvalues, Int64* data);
  virtual size_t read(size_t nvalues, uInt64* data);
  virtual size_t read(size_t nvalues, Float* data);
  virtual size_t read(size_t nvalues, Double* data);
  virtual size_t read(size_t nvalues, Complex* value);
  virtual size_t read(size_t nvalues, DComplex* value);
  virtual size_t read(size_t nvalues, String* value);
  // </group>
 
 private:
  // Initialize the <src>itsSize</src> and <src>itsCopy</src> variables.
  void init();
 
  template <typename T>
  void initType(uInt& size, Bool& copy) const;
 
  template <typename T>
  size_t writeGeneric(size_t nvalues, const T* value, size_t type_size, bool copy);
  template <typename T>
  size_t readGeneric(size_t nvalues, T* value, size_t type_size, bool copy);
 
  // # The data.
  std::shared_ptr<DataConversion> itsConversion;
  uInt itsSizeChar;
  uInt itsSizeuChar;
  uInt itsSizeShort;
  uInt itsSizeuShort;
  uInt itsSizeInt;
  uInt itsSizeuInt;
  uInt itsSizeInt64;
  uInt itsSizeuInt64;
  uInt itsSizeFloat;
  uInt itsSizeDouble;
  Bool itsCopyChar;
  Bool itsCopyuChar;
  Bool itsCopyShort;
  Bool itsCopyuShort;
  Bool itsCopyInt;
  Bool itsCopyuInt;
  Bool itsCopyInt64;
  Bool itsCopyuInt64;
  Bool itsCopyFloat;
  Bool itsCopyDouble;
  // # The buffer
  char* itsBuffer;
  uInt itsBufferLength;
};
 
}  // namespace casacore
 
#endif