TiledColumnStMan.h

Go to the documentation of this file.

// # TiledColumnStMan.h: Tiled Column Storage Manager
// # Copyright (C) 1995,1996,1997,1999,2001
// # 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 TABLES_TILEDCOLUMNSTMAN_H
#define TABLES_TILEDCOLUMNSTMAN_H
 
// # Includes
#include <casacore/casa/aips.h>
#include <casacore/tables/DataMan/TiledStMan.h>
#include <casacore/casa/Arrays/IPosition.h>
#include <casacore/casa/BasicSL/String.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// # Forward Declarations
 
// <summary>
// Tiled Column Storage Manager.
// </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=TiledStMan>TiledStMan</linkto>
//   <li> <linkto class=TSMCube>TSMCube</linkto>
//   <li> <linkto class=ROTiledStManAccessor>ROTiledStManAccessor</linkto>
//        for a discussion of the maximum cache size
// </prerequisite>
 
// <etymology>
// TiledColumnStMan is the Tiled Storage Manager storing
// an entire column as one hypercube.
// </etymology>
 
// <synopsis>
// TiledColumnStMan is a derivation from TiledStMan, the abstract
// tiled storage manager class. A description of the basics
// of tiled storage managers is given in the
// <linkto module=Tables:TiledStMan>Tables module</linkto> description.
// <p>
// TiledColumnStMan allows the user to create a tiled hypercube for
// an entire data column and extend it in an automatic way.
// It is meant to be used for fixed shaped data which have to
// be accessed in various directions.
// <p>
// The TiledColumnStMan has the following (extra) properties:
// <ul>
//  <li> Addition of a row results in the extension of the hypercube.
//       The data cells in all rows have to have the same shape. Therefore
//       the columns stored by a TiledColumnStMan storage manager
//       have to be fixed shaped (i.e. FixedShape attribute set in their
//       column descriptions).
//  <li> Coordinates for the hypercubes can be defined and (of course)
//       their shapes have to match the hypercube shape.
//       Their values have to be put explicitly (so it is not possible
//       to define them via an extendHypercube call like in
//       <linkto class=TiledDataStMan>TiledDataStMan</linkto>).
//  <li> The tile shape of the hypercube has to be defined by means
//       of the TiledColumnStMan constructor.
// </ul>
// </synopsis>
 
// <motivation>
// This tiled storage manager does not require any special action
// (like calling add/extendHypercube) when used with a column
// containing equally shaped arrays.
// </motivation>
 
// <example>
// <srcblock>
//  // Define the table description and the columns in it.
//  TableDesc td ("", "1", TableDesc::Scratch);
//  td.addColumn (ArrayColumnDesc<float>  ("RA", 1));
//  td.addColumn (ArrayColumnDesc<float>  ("Dec", 1));
//  td.addColumn (ScalarColumnDesc<float> ("Velocity"));
//  td.addColumn (ArrayColumnDesc<float>  ("Image", 2));
//  // Define the 3-dim hypercolumn with its data and coordinate columns.
//  // Note that its dimensionality must be one higher than the dimensionality
//  // of the data cells.
//  td.defineHypercolumn ("TSMExample",
//            3,
//            stringToVector ("Image"),
//            stringToVector ("RA,Dec,Velocity"));
//  // Now create a new table from the description.
//  SetupNewTable newtab("tTiledColumnStMan_tmp.data", td, Table::New);
//  // Create a TiledColumnStMan storage manager for the hypercolumn
//  // and bind the columns to it.
//  // The tile shape has to be specified for the storage manager.
//  TiledColumnStMan sm1 ("TSMExample", IPosition(3,16,32,32));
//  newtab.bindAll (sm1);
//  // Create the table.
//  Table table(newtab);
//  // Define the values for the coordinates of the hypercube.
//  Vector<float> raValues(512);
//  Vector<float> DecValues(512);
//  indgen (raValues);
//  indgen (decValues, float(100));
//  ArrayColumn<float> ra (table, "RA");
//  ArrayColumn<float> dec (table, "Dec");
//  ScalarColumn<float> velocity (table, "Velocity");
//  ArrayColumn<float> image (table, "Image");
//  Cube<float> imageValues(IPosition(2,512,512));
//  indgen (imageValues);
//  // Write some data into the data columns.
//  for (uInt i=0; i<64; i++) {
//      table.addRow();
//  image.put (i, imageValues);
//      // The RA and Dec have to be put only once, because they
//      // are the same for each row.
//      if (i == 0) {
//          ra.put (i, raValues);
//          dec.put (i, decValues);
//      }
//      velocity.put (i, float(i));
//  }
// </srcblock>
// </example>
 
// # <todo asof="$DATE:$">
// # A List of bugs, limitations, extensions or planned refinements.
// # </todo>
 
class TiledColumnStMan : public TiledStMan {
 public:
  // Create a TiledDataStMan storage manager for the hypercolumn
  // with the given name. The columns used should have the FixedShape
  // attribute set.
  // The hypercolumn name is also the name of the storage manager.
  // The given tile shape will be used.
  // The given maximum cache size in bytes (default is unlimited) is
  // persistent, thus will be reused when the table is read back.
  // Note that the class
  // <linkto class=ROTiledStManAccessor>ROTiledStManAccessor</linkto>
  // allows one to overwrite the maximum cache size temporarily.
  // Its description contains a discussion about the effects of
  // setting a maximum cache.
  // <br>The constructor taking a Record expects fields in the record with
  // the name of the arguments in uppercase. If not defined, their
  // default value is used.
  // <group>
  TiledColumnStMan(const String& hypercolumnName, const IPosition& tileShape,
                   uInt64 maximumCacheSize = 0);
  TiledColumnStMan(const String& hypercolumnName, const Record& spec);
  // </group>
 
  ~TiledColumnStMan();
 
  // Forbid copy constructor.
  TiledColumnStMan(const TiledColumnStMan&) = delete;
 
  // Forbid assignment.
  TiledColumnStMan& operator=(const TiledColumnStMan&) = delete;
 
  // Clone this object.
  // It does not clone TSMColumn objects possibly used.
  virtual DataManager* clone() const;
 
  // TiledColumnStMan can always access a column.
  virtual Bool canAccessColumn() const;
 
  // Get the type name of the data manager (i.e. TiledColumnStMan).
  virtual String dataManagerType() const;
 
  // Make the object from the type name string.
  // This function gets registered in the DataManager "constructor" map.
  static DataManager* makeObject(const String& dataManagerType, const Record& spec);
 
 private:
  // Create a TiledColumnStMan.
  // This constructor is private, because it should only be used
  // by makeObject.
  TiledColumnStMan();
 
  // Get the (default) tile shape.
  virtual IPosition defaultTileShape() const;
 
  // Add rows to the storage manager.
  // This will extend the hypercube.
  void addRow64(rownr_t nrrow);
 
  // Get the hypercube in which the given row is stored.
  virtual TSMCube* getHypercube(rownr_t rownr);
 
  // Get the hypercube in which the given row is stored.
  // It also returns the position of the row in that hypercube.
  virtual TSMCube* getHypercube(rownr_t rownr, IPosition& position);
 
  // Check if the hypercolumn definition fits this storage manager.
  virtual void setupCheck(const TableDesc& tableDesc, const Vector<String>& dataNames) const;
 
  // Flush and optionally fsync the data.
  // It returns a True status if it had to flush (i.e. if data have changed).
  virtual Bool flush(AipsIO&, Bool fsync);
 
  // Let the storage manager create files as needed for a new table.
  // This allows a column with an indirect array to create its file.
  virtual void create64(rownr_t nrrow);
 
  // Read the header info.
  virtual void readHeader(rownr_t nrrow, Bool firstTime);
 
  // # Declare data members.
  IPosition tileShape_p;
};
 
}  // namespace casacore
 
#endif