LECanonicalIO.h

Go to the documentation of this file.

// # LECanonicalIO.h: Class for IO in little endian canonical format
// # Copyright (C) 2002
// # 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_LECANONICALIO_H
#define CASA_LECANONICALIO_H
 
#include <casacore/casa/aips.h>
#include <casacore/casa/IO/TypeIO.h>
#include <casacore/casa/BasicSL/Complexfwd.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
class ByteIO;
class String;
 
// <summary>Class for IO in little endian canonical 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=LECanonicalConversion>LECanonicalConversion</linkto>
// </prerequisite>
 
// <synopsis>
// LECanonicalIO is a specialization of class TypeIO to store
// data in little endian canonical format.
// <p>
// The class converts the data to/from canonical 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>
// LECanonical format is little-endian IEEE format, where longs are 8 bytes.
// Bools are stored as bits to be as space-efficient as possible.
// This means that on a 32-bit SUN or HP conversions only have to be done
// for Bools and longs. For a DEC-alpha, however, the data will always
// be converted because it is a little-endian machine.
// </synopsis>
 
class LECanonicalIO : public TypeIO {
 public:
  // Constructor.
  // The read/write functions will use the given ByteIO object
  // as the data store.
  // <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.
  explicit LECanonicalIO(const std::shared_ptr<ByteIO>& byteIO, uInt bufferLength = 4096);
 
  // The copy constructor uses reference semantics
  LECanonicalIO(const LECanonicalIO& canonicalIO);
 
  // The assignment operator uses reference semantics
  LECanonicalIO& operator=(const LECanonicalIO& canonicalIO);
 
  // Destructor, deletes allocated memory.
  ~LECanonicalIO();
 
  // 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:
  // # The buffer
  char* itsBuffer;
  uInt itsBufferLength;
};
 
}  // namespace casacore
 
#endif