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TSMColumn.h
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00001 //# TSMColumn.h: A column in the Tiled Storage Manager
00002 //# Copyright (C) 1995,1996,1997,1999
00003 //# Associated Universities, Inc. Washington DC, USA.
00004 //#
00005 //# This library is free software; you can redistribute it and/or modify it
00006 //# under the terms of the GNU Library General Public License as published by
00007 //# the Free Software Foundation; either version 2 of the License, or (at your
00008 //# option) any later version.
00009 //#
00010 //# This library is distributed in the hope that it will be useful, but WITHOUT
00011 //# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
00012 //# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
00013 //# License for more details.
00014 //#
00015 //# You should have received a copy of the GNU Library General Public License
00016 //# along with this library; if not, write to the Free Software Foundation,
00017 //# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
00018 //#
00019 //# Correspondence concerning AIPS++ should be addressed as follows:
00020 //#        Internet email: aips2-request@nrao.edu.
00021 //#        Postal address: AIPS++ Project Office
00022 //#                        National Radio Astronomy Observatory
00023 //#                        520 Edgemont Road
00024 //#                        Charlottesville, VA 22903-2475 USA
00025 //#
00026 //# $Id: TSMColumn.h 20551 2009-03-25 00:11:33Z Malte.Marquarding $
00027 
00028 #ifndef TABLES_TSMCOLUMN_H
00029 #define TABLES_TSMCOLUMN_H
00030 
00031 //# Includes
00032 #include <casa/aips.h>
00033 #include <tables/Tables/StManColumn.h>
00034 #include <casa/Arrays/IPosition.h>
00035 #include <casa/BasicSL/String.h>
00036 
00037 namespace casa { //# NAMESPACE CASA - BEGIN
00038 
00039 //# Forward Declarations
00040 class TiledStMan;
00041 class TSMDataColumn;
00042 class TSMCoordColumn;
00043 class TSMIdColumn;
00044 
00045 
00046 // <summary>
00047 // A column in the Tiled Storage Manager
00048 // </summary>
00049 
00050 // <use visibility=local>
00051 
00052 // <reviewed reviewer="UNKNOWN" date="before2004/08/25" tests="">
00053 // </reviewed>
00054 
00055 // <prerequisite>
00056 //# Classes you should understand before using this one.
00057 //   <li> <linkto class=StManColumn>StManColumn</linkto>
00058 //   <li> <linkto class=TiledStMan>TiledStMan</linkto>
00059 // </prerequisite>
00060 
00061 // <etymology>
00062 // TSMColumn handles a column for the Tiled Storage Manager.
00063 // </etymology>
00064 
00065 // <synopsis> 
00066 // TSMColumn serves 2 purposes:
00067 // <ol>
00068 //  <li> It is the initial object for all columns in TiledStMan.
00069 //  <li> It serves as a base class for the specialized TiledStMan
00070 //       column classes dealing with data, coordinates and id values.
00071 // </ol>
00072 // The protocol used for creating the derived
00073 // <linkto class=TSMDataColumn>TSMDataColumn</linkto>,
00074 // <linkto class=TSMCoordColumn>TSMCoordColumn</linkto>, and
00075 // <linkto class=TSMIdColumn>TSMIdColumn</linkto>
00076 // objects is somewhat complicated. It works as follows:
00077 // <br>
00078 // When the table is set up, a TSMColumn object gets created for all
00079 // columns in a TiledStMan storage manager. The TiledStMan initialization
00080 // function lets each TSMColumn object create its specialized TSMXXColumn
00081 // object (using make{Coord,Id,Data}Column). At the end of the setup process
00082 // the TSMColumn objects are deleted and the DataManagerColumn pointers
00083 // in the BaseColumn objects get replaced by those to the specialized
00084 // objects. In that way no needless virtual function calls are done.
00085 // </synopsis> 
00086 
00087 // <motivation>
00088 // TSMColumn is needed for the initial DataManagerColumn setup process.
00089 // It is also useful as a base class for all TiledStMan column objects.
00090 // </motivation>
00091 
00092 //# <todo asof="$DATE:$">
00093 //# A List of bugs, limitations, extensions or planned refinements.
00094 //# </todo>
00095 
00096 
00097 class TSMColumn : public StManColumn
00098 {
00099 public:
00100 
00101     // Create a column of the given type.
00102     // It will maintain a pointer to its parent storage manager.
00103     TSMColumn (TiledStMan* stman, int dataType, const String& columnName);
00104 
00105     // Frees up the storage.
00106     virtual ~TSMColumn();
00107 
00108     // Get the name of the column.
00109     const String& columnName() const;
00110 
00111     // Return the data type of the column.
00112     virtual int dataType() const;
00113 
00114     // Set the fixed shape of the column.
00115     void setShapeColumn (const IPosition& shape);
00116 
00117     // Get the fixed shape of the column.
00118     const IPosition& shapeColumn() const;
00119 
00120     // Make a TSM data column object.
00121     // Add the pixel length to the total data pixel length.
00122     TSMDataColumn* makeDataColumn();
00123 
00124     // Make a TSM coordinate column object.
00125     TSMCoordColumn* makeCoordColumn (uInt axesNumber);
00126 
00127     // Make a TSM id column object.
00128     TSMIdColumn* makeIdColumn();
00129 
00130     // Unlink the underlying column.
00131     // It clears the pointer and returns its original value.
00132     // This is used to get a pointer directly to the underlying TSMXXColumn
00133     // object in the BaseColumn classes. In that way only 1 instead
00134     // of 2 virtual function calls are needed for a get or put.
00135     TSMColumn* unlink();
00136 
00137 
00138 protected:
00139     // The storage manager.
00140     TiledStMan* stmanPtr_p;
00141     // The data type of the data (as defined in DataType.h).
00142     int   dtype_p;
00143     // The name of the column.
00144     String name_p;
00145     // The fixed shape of the column.
00146     IPosition columnShape_p;
00147     // The specialized column object (i.e. data, coordinate or id).
00148     TSMColumn* colPtr_p;
00149 
00150     // The copy constructor can only be used to copy a derived class.
00151     TSMColumn (const TSMColumn& that);
00152 
00153 private:
00154     // Forbid assignment.
00155     TSMColumn& operator= (const TSMColumn&);
00156 };
00157 
00158 
00159 inline const String& TSMColumn::columnName() const
00160     { return name_p; }
00161 
00162 inline const IPosition& TSMColumn::shapeColumn() const
00163     { return columnShape_p; }
00164 
00165 
00166 
00167 
00168 } //# NAMESPACE CASA - END
00169 
00170 #endif