MemoryStMan.h

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// # MemoryStMan.h: Storage manager for tables using memory
// # 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_MEMORYSTMAN_H
#define TABLES_MEMORYSTMAN_H
 
// # Includes
#include <casacore/casa/aips.h>
#include <casacore/tables/DataMan/MSMBase.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// <summary>
// Memory-based table storage manager class
// </summary>
 
// <use visibility=export>
 
// <reviewed reviewer="UNKNOWN" date="before2004/08/25" tests="">
// </reviewed>
 
// <prerequisite>
// # Classes you should understand before using this one.
//   <li> <linkto class=DataManager>DataManager</linkto>
//   <li> <linkto class=MSMColumn>MSMColumn</linkto>
// </prerequisite>
 
// <synopsis>
// MemoryStMan is a table storage manager based in memory.
// It holds all data in the columns in memory and deletes them
// when the table gets closed.
// It contains pointers to the underlying MSMColumn objects,
// which do the actual data handling.
//
// The Memory storage manager does fully support addition and removal
// of rows and columns.
//
// The primary use of this storage manager is for a memory-based table,
// but it can also be used for temporary columns in disk-based tables.
// When reopening a disk-based table, possible columns stored with
// MemoryStMan will be initialized to 0.
// An important issue is synchronizing tables containing MemoryStMan
// storage managers in case of concurrent access. Because its data are
// not stored on disk, there is no way to synchronize the data if another
// process changed data or added or deleted rows. If the number or rows
// has changed, rows will be added or deleted as needed. Row deletion
// will be done at the end of the table.
// </synopsis>
 
// # <todo asof="$DATE:$">
// # A List of bugs, limitations, extensions or planned refinements.
// # </todo>
 
class MemoryStMan : public MSMBase {
 public:
  // Create an Memory storage manager.
  // Its name will be blank.
  MemoryStMan();
 
  // Create an Memory storage manager with the given name.
  // Its name can be used later in e.g. Table::addColumn to
  // add a column to this storage manager.
  MemoryStMan(const String& storageManagerName);
 
  ~MemoryStMan();
};
 
}  // namespace casacore
 
#endif