MSMIndColumn.h

Go to the documentation of this file.

// # MSMIndColumn.h: Memory storage manager for variable shaped table arrays
// # Copyright (C) 2003
// # 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 TABLES_MSMINDCOLUMN_H
#define TABLES_MSMINDCOLUMN_H
 
// # Includes
#include <casacore/casa/aips.h>
#include <casacore/tables/DataMan/MSMColumn.h>
#include <casacore/tables/DataMan/MSMBase.h>
#include <casacore/casa/Arrays/IPosition.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// <summary>
// Mmeory storage manager for variable shaped table arrays
// </summary>
 
// <use visibility=local>
 
// <reviewed reviewer="UNKNOWN" date="before2004/08/25" tests="">
// </reviewed>
 
// <prerequisite>
// # Classes you should understand before using this one.
//   <li> MSMBase
//   <li> MSMColumn
// </prerequisite>
 
// <synopsis>
// StManColumnArrayAipsIO handles indirect arrays in a table column.
//
// An array (or section of an array) is only read when needed.
// It, however, caches the array shape using the helper class
// StIndArray. Pointers to these objects
// are maintained using the standard StManColumnAipsIO facilities.
// When the column gets written, the offsets in the StManArrayFile file
// get written. Those will be read back when the column is read in.
//
// When a row gets deleted or when the array gets bigger, the file space
// is lost. This storage manager is a simple one and no attempts
// are done to make it smart.
// </synopsis>
 
// # <todo asof="$DATE:$">
// # A List of bugs, limitations, extensions or planned refinements.
// # </todo>
 
class MSMIndColumn : public MSMColumn {
 public:
  // Create a column of the given type.
  MSMIndColumn(MSMBase*, int dataType);
 
  // Frees up the storage.
  ~MSMIndColumn();
 
  // Forbid copy constructor.
  MSMIndColumn(const MSMIndColumn&) = delete;
 
  // Forbid assignment.
  MSMIndColumn& operator=(const MSMIndColumn&) = delete;
 
  // Set the (fixed) shape of the arrays in the entire column.
  void setShapeColumn(const IPosition& shape);
 
  // Get the column shape.
  const IPosition& columnShape() const { return fixedShape_p; }
 
  // Set the shape of the array in the given row and allocate the array
  // in the file.
  void setShape(rownr_t rownr, const IPosition& shape);
 
  // Is the shape defined (i.e. is there an array) in this row?
  Bool isShapeDefined(rownr_t rownr);
 
  // Get the dimensionality of the item in the given row.
  // 0 is returned if there is no array.
  uInt ndim(rownr_t rownr);
 
  // Get the shape of the array in the given row.
  // An zero-length IPosition is returned if there is no array.
  IPosition shape(rownr_t rownr);
 
  // This storage manager can handle changing array shapes.
  Bool canChangeShape() const;
 
  // Get an array value in the given row.
  // The buffer given by <src>arr</src> has to have the correct length
  // (which is guaranteed by the ArrayColumn get function).
  void getArrayV(rownr_t rownr, ArrayBase& arr);
 
  // Put an array value into the given row.
  // The buffer given by <src>arr</src> has to have the correct length
  // (which is guaranteed by the ArrayColumn put function).
  void putArrayV(rownr_t rownr, const ArrayBase& arr);
 
  // Get a section of the array in the given row.
  // The buffer given by <src>arr</src> has to have the correct length
  // (which is guaranteed by the ArrayColumn getSlice function).
  void getSliceV(rownr_t rownr, const Slicer&, ArrayBase& arr);
 
  // Put into a section of the array in the given row.
  // The buffer given by <src>arr</src> has to have the correct length
  // (which is guaranteed by the ArrayColumn putSlice function).
  void putSliceV(rownr_t rownr, const Slicer&, const ArrayBase& arr);
 
  // Remove the value in the given row.
  // This will result in lost file space.
  void remove(rownr_t rownr);
 
 private:
  class Data {
   public:
    Data(const IPosition& shape, int dtype, int elemSize);
    ~Data();
    Data(const Data&) = delete;
    Data& operator=(const Data&) = delete;
    const IPosition& shape() const { return shape_p; }
    void* data() { return data_p; }
 
   private:
    IPosition shape_p;
    void* data_p;
    bool data_is_string;
  };
  // The shape of all arrays in case it is fixed.
  IPosition fixedShape_p;
  // The size at the start of the data (for the IPosition).
  uInt startSize_p;
 
  // Delete the array in the given row.
  void deleteArray(rownr_t rownr);
 
  // Read the shape at the given row.
  // It throws an exception if undefined.
  Data* getShape(rownr_t rownr);
 
  // Get a pointer to the data array.
  void* getDataPtr(rownr_t rownr) { return (char*)(getShape(rownr)) + startSize_p; }
};
 
}  // namespace casacore
 
#endif