ScaRecordColData.h

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// # ScaRecordColData.h: Access to a table column containing scalar records
// # Copyright (C) 1998
// # 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_SCARECORDCOLDATA_H
#define TABLES_SCARECORDCOLDATA_H
 
// # Includes
#include <casacore/casa/aips.h>
#include <casacore/casa/Arrays/ArrayFwd.h>
#include <casacore/tables/Tables/PlainColumn.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// # Forward Declarations
class ColumnSet;
class ScalarRecordColumnDesc;
class AipsIO;
 
// <summary>
// Access to a table column containing scalar records.
// </summary>
 
// <use visibility=local>
 
// <reviewed reviewer="Wim Brouw" date="1998/12/09" tests="tRecordColumn.cc">
// </reviewed>
 
// <prerequisite>
// # Classes you should understand before using this one.
//   <li> <linkto class=PlainColumn>PlainColumn</linkto>
//   <li> <linkto class=ScalarRecordColumnDesc>ScalarRecordColumnDesc</linkto>
//   <li> <linkto class=Table>Table</linkto>
// </prerequisite>
 
// <etymology>
// ScalarRecordColumnData represents a table column containing scalars.
// </etymology>
 
// <synopsis>
// The class ScalarRecordColumnData is derived from PlainColumn.
// It implements the virtual functions accessing a table column
// containing scalars holding records.
// <br>
// It is possible to access an scalar in an individual cell (i.e. table row)
// or in the entire column.
// <p>
// The main task of this class is to communicate with the data manager
// column object. This consists of:
// <ul>
//  <li> Binding itself to a data manager.
//  <li> Letting the data manager create its column object.
//  <li> Closing the data manager column object (in putFileDerived).
//  <li> Reconstructing the data manager object for an existing table
//         (in getFileDerived).
//  <li> Transferring get/put calls to the data manager column object.
// </ul>
//
// The class is hidden from the user by the envelope class ScalarColumn.
// If used directly by other Table classes, it should be done with care.
// It assumes that the arrays in the various get and put functions have
// the correct length. ScalarColumn does that check.
// </synopsis>
 
// <todo asof="$DATE:$">
// # A List of bugs, limitations, extensions or planned refinements.
//  <li> Introduce a class ArrayRecordColumnData to support arrays of records.
// </todo>
 
class ScalarRecordColumnData : public PlainColumn {
 public:
  // Construct a scalar column object from the given description
  // in the given column set.
  // This constructor is used by ScalarRecordColumnDesc::makeColumn.
  ScalarRecordColumnData(const ScalarRecordColumnDesc*, ColumnSet*);
 
  ~ScalarRecordColumnData();
 
  // Copy constructor cannot be used.
  ScalarRecordColumnData(const ScalarRecordColumnData&) = delete;
 
  // Assignment cannot be used.
  ScalarRecordColumnData& operator=(const ScalarRecordColumnData&) = delete;
 
  // Initialize the rows from startRownr till endRownr (inclusive)
  // with the default value defined in the column description.
  virtual void initialize(rownr_t startRownr, rownr_t endRownr);
 
  // Test if the given cell contains a defined value.
  virtual Bool isDefined(rownr_t rownr) const;
 
  // Get the value from a particular cell.
  virtual void get(rownr_t rownr, void*) const;
 
  // Get the array of all values in the column.
  // The length of the buffer pointed to by dataPtr must match
  // the actual length. This is checked by ScalarColumn.
  virtual void getScalarColumn(ArrayBase& dataPtr) const;
 
  // Get the array of some values in the column (on behalf of RefColumn).
  // The length of the buffer pointed to by dataPtr must match
  // the actual length. This is checked by ScalarColumn.
  virtual void getScalarColumnCells(const RefRows& rownrs, ArrayBase& dataPtr) const;
 
  // Put the value in a particular cell.
  // The length of the buffer pointed to by dataPtr must match
  // the actual length. This is checked by ScalarColumn.
  virtual void put(rownr_t rownr, const void* dataPtr);
 
  // Put the array of all values in the column.
  // The length of the buffer pointed to by dataPtr must match
  // the actual length. This is checked by ScalarColumn.
  virtual void putScalarColumn(const ArrayBase& dataPtr);
 
  // Put the array of some values in the column (on behalf on RefColumn).
  // The length of the buffer pointed to by dataPtr must match
  // the actual length. This is checked by ScalarColumn.
  virtual void putScalarColumnCells(const RefRows& rownrs, const ArrayBase& dataPtr);
 
  // Add this column and its data to the Sort object.
  // Sorting on records is not supported, so an exception is thrown.
  // <group>
  virtual void makeSortKey(Sort&, std::shared_ptr<BaseCompare>& cmpObj, Int order,
                           std::shared_ptr<ArrayBase>& dataSave);
  // Do it only for the given row numbers.
  virtual void makeRefSortKey(Sort&, std::shared_ptr<BaseCompare>& cmpObj, Int order,
                              const Vector<rownr_t>& rownrs, std::shared_ptr<ArrayBase>& dataSave);
  // </group>
 
  // Allocate value buffers for the table iterator.
  // Iteration based on records is not supported, so an exception is thrown.
  virtual void allocIterBuf(void*& lastVal, void*& curVal, std::shared_ptr<BaseCompare>& cmpObj);
 
  // Free the value buffers allocated by allocIterBuf.
  virtual void freeIterBuf(void*& lastVal, void*& curVal);
 
  // Create a data manager column object for this column.
  virtual void createDataManagerColumn();
 
 private:
  // Write the column data.
  // The control information is written into the given AipsIO object,
  // while the data is written/flushed by the data manager.
  virtual void putFileDerived(AipsIO&);
 
  // Read the column data back.
  // The control information is read from the given AipsIO object.
  // This is used to bind the column to the appropriate data manager.
  // Thereafter the data manager gets opened.
  virtual void getFileDerived(AipsIO&, const ColumnSet&);
 
  // Handle getting and putting a record.
  // It is stored as a Vector of uChar.
  // <group>
  void getRecord(rownr_t rownr, TableRecord& rec) const;
  void putRecord(rownr_t rownr, const TableRecord& rec);
  // </group>
};
 
}  // namespace casacore
 
#endif