DataConversion.h

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// # DataConversion.h: Abstract base class with functions to convert any 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_DATACONVERSION_H
#define CASA_DATACONVERSION_H
 
// # Includes
#include <casacore/casa/aips.h>
#include <casacore/casa/OS/Conversion.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// <summary>
// Abstract base class with functions to convert any format
// </summary>
 
// <use visibility=export>
 
// <reviewed reviewer="Friso Olnon" date="1996/11/06" tests="tDataConversion" demos="">
// </reviewed>
 
// <synopsis>
// This abstract base class contains pure virtual functions to convert
// from any foreign data format to local format and vice-versa.
// Classes derived from it implement the functions for a specific
// foreign format (e.g.
// <linkto class=CanonicalDataConversion:description>CanonicalDataConversion
// </linkto>,
// <linkto class=VAXDataConversion:description>VAXDataConversion</linkto>,
// <linkto class=IBMDataConversion:description>IBMDataConversion</linkto>).
// <linkto class=RawDataConversion:description>RawDataConversion</linkto>).
// </synopsis>
 
// <example>
// <srcblock>
// // Construct the correct conversion object.
// DataConversion* conv = new IBMDataConversion();
// // Say that you read a block of 256 floats (in IBM-format).
// char buffer[1024];
// read (fd, buffer, 1024);
// // Convert the float to local format.
// float values[256];
// conv->toLocal (values, buffer, 256);
// </srcblock>
// </example>
 
// <motivation>
// The abstract base class allows one to construct the correct conversion
// object at the beginning. Thereafter this base class can be used and
// polymorphism takes care of picking the correct functions.
// </motivation>
 
// <todo asof="$DATE$">
//  <li> Support data type long double.
// </todo>
 
class DataConversion {
 public:
  // Construct the object.
  DataConversion();
 
  virtual ~DataConversion();
 
  template <typename T>
  size_t toLocalGeneric(T& to, const void* from) const {
    return toLocal(to, from);
  }
 
  template <typename T>
  size_t toLocalGeneric(T* to, const void* from, size_t nr) const {
    return toLocal(to, from, nr);
  }
 
  template <typename T>
  size_t fromLocalGeneric(void* to, T from) const {
    return fromLocal(to, from);
  }
 
  template <typename T>
  size_t fromLocalGeneric(void* to, const T* from, size_t nr) const {
    return fromLocal(to, from, nr);
  }
 
  template <typename T>
  bool canCopyGeneric() const {
    return canCopy(static_cast<const T*>(nullptr));
  }
 
  template <typename T>
  unsigned int externalSizeGeneric() const {
    return externalSize(static_cast<const T*>(nullptr));
  }
 
  // Convert one value from foreign format to local format.
  // The from and to buffer should not overlap.
  // <note>
  // The char version handles characters (thus may involve conversion
  // EBCDIC to ASCII), while the unsigned chars are simply bytes.
  // </note>
  // <group>
  virtual size_t toLocal(char& to, const void* from) const = 0;
  virtual size_t toLocal(unsigned char& to, const void* from) const = 0;
  virtual size_t toLocal(short& to, const void* from) const = 0;
  virtual size_t toLocal(unsigned short& to, const void* from) const = 0;
  virtual size_t toLocal(int& to, const void* from) const = 0;
  virtual size_t toLocal(unsigned int& to, const void* from) const = 0;
  virtual size_t toLocal(Int64& to, const void* from) const = 0;
  virtual size_t toLocal(uInt64& to, const void* from) const = 0;
  virtual size_t toLocal(float& to, const void* from) const = 0;
  virtual size_t toLocal(double& to, const void* from) const = 0;
  // </group>
 
  // Convert nr values from foreign format to local format.
  // The from and to buffer should not overlap.
  // <note>
  // The char version handles characters (thus may involve conversion
  // EBCDIC to ASCII), while the unsigned chars are simply bytes.
  // </note>
  // <group>
  virtual size_t toLocal(char* to, const void* from, size_t nr) const = 0;
  virtual size_t toLocal(unsigned char* to, const void* from, size_t nr) const = 0;
  virtual size_t toLocal(short* to, const void* from, size_t nr) const = 0;
  virtual size_t toLocal(unsigned short* to, const void* from, size_t nr) const = 0;
  virtual size_t toLocal(int* to, const void* from, size_t nr) const = 0;
  virtual size_t toLocal(unsigned int* to, const void* from, size_t nr) const = 0;
  virtual size_t toLocal(Int64* to, const void* from, size_t nr) const = 0;
  virtual size_t toLocal(uInt64* to, const void* from, size_t nr) const = 0;
  virtual size_t toLocal(float* to, const void* from, size_t nr) const = 0;
  virtual size_t toLocal(double* to, const void* from, size_t nr) const = 0;
  // </group>
 
  // Convert one value from local format to foreign format.
  // The from and to buffer should not overlap.
  // <note>
  // The char version handles characters (thus may involve conversion
  // ASCII to EBCDIC), while the unsigned chars are simply bytes.
  // </note>
  // <group>
  virtual size_t fromLocal(void* to, char from) const = 0;
  virtual size_t fromLocal(void* to, unsigned char from) const = 0;
  virtual size_t fromLocal(void* to, short from) const = 0;
  virtual size_t fromLocal(void* to, unsigned short from) const = 0;
  virtual size_t fromLocal(void* to, int from) const = 0;
  virtual size_t fromLocal(void* to, unsigned int from) const = 0;
  virtual size_t fromLocal(void* to, Int64 from) const = 0;
  virtual size_t fromLocal(void* to, uInt64 from) const = 0;
  virtual size_t fromLocal(void* to, float from) const = 0;
  virtual size_t fromLocal(void* to, double from) const = 0;
  // </group>
 
  // Convert nr values from local format to foreign format.
  // The from and to buffer should not overlap.
  // <note>
  // The char version handles characters (thus may involve conversion
  // ASCII to EBCDIC), while the unsigned chars are simply bytes.
  // </note>
  // <group>
  virtual size_t fromLocal(void* to, const char* from, size_t nr) const = 0;
  virtual size_t fromLocal(void* to, const unsigned char* from, size_t nr) const = 0;
  virtual size_t fromLocal(void* to, const short* from, size_t nr) const = 0;
  virtual size_t fromLocal(void* to, const unsigned short* from, size_t nr) const = 0;
  virtual size_t fromLocal(void* to, const int* from, size_t nr) const = 0;
  virtual size_t fromLocal(void* to, const unsigned int* from, size_t nr) const = 0;
  virtual size_t fromLocal(void* to, const Int64* from, size_t nr) const = 0;
  virtual size_t fromLocal(void* to, const uInt64* from, size_t nr) const = 0;
  virtual size_t fromLocal(void* to, const float* from, size_t nr) const = 0;
  virtual size_t fromLocal(void* to, const double* from, size_t nr) const = 0;
  // </group>
 
  // Determine if the data for a data type can be simply copied, thus
  // if no conversion is needed.
  // <group>
  virtual Bool canCopy(const char*) const = 0;
  virtual Bool canCopy(const unsigned char*) const = 0;
  virtual Bool canCopy(const short*) const = 0;
  virtual Bool canCopy(const unsigned short*) const = 0;
  virtual Bool canCopy(const int*) const = 0;
  virtual Bool canCopy(const unsigned int*) const = 0;
  virtual Bool canCopy(const Int64*) const = 0;
  virtual Bool canCopy(const uInt64*) const = 0;
  virtual Bool canCopy(const float*) const = 0;
  virtual Bool canCopy(const double*) const = 0;
  // </group>
 
  // Get the external size of the data type.
  // <group>
  virtual unsigned int externalSize(const char*) const = 0;
  virtual unsigned int externalSize(const unsigned char*) const = 0;
  virtual unsigned int externalSize(const short*) const = 0;
  virtual unsigned int externalSize(const unsigned short*) const = 0;
  virtual unsigned int externalSize(const int*) const = 0;
  virtual unsigned int externalSize(const unsigned int*) const = 0;
  virtual unsigned int externalSize(const Int64*) const = 0;
  virtual unsigned int externalSize(const uInt64*) const = 0;
  virtual unsigned int externalSize(const float*) const = 0;
  virtual unsigned int externalSize(const double*) const = 0;
  // </group>
};
 
inline DataConversion::DataConversion() {}
 
}  // namespace casacore
 
#endif