TiledFileAccess.h

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// # TiledFileAccess.h: Tiled access to an array in a file
// # Copyright (C) 2001,2002
// # 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_TILEDFILEACCESS_H
#define TABLES_TILEDFILEACCESS_H
 
// # Includes
#include <casacore/casa/aips.h>
#include <casacore/tables/DataMan/TSMCube.h>
#include <casacore/tables/DataMan/TSMOption.h>
#include <casacore/casa/Utilities/DataType.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// # Forward Declarations
class TiledFileHelper;
class Slicer;
 
// <summary>
// Tiled access to an array in a file.
// </summary>
 
// <use visibility=export>
 
// <reviewed reviewer="" date="" tests="tTiledFileAccess.cc">
// </reviewed>
 
// <prerequisite>
// # Classes you should understand before using this one.
//   <li> Description of Tiled Storage Manager in module file
//        <linkto module=Tables:TiledStMan>Tables.h</linkto>
//   <li> <linkto class=ROTiledStManAccessor>ROTiledStManAccessor</linkto>
//        for a discussion of the maximum cache size
// </prerequisite>
 
// <synopsis>
// TiledFileAccess is a class that makes it possible to access
// an arbitrary array in a file using the tiled storage manager classes.
// It can handle arrays of any type supported by the tiled storage
// managers. The array can be in big or little endian canonical format.
// <p>
// See <linkto class=ROTiledStManAccessor>ROTiledStManAccessor</linkto>
// for a more detailed discussion.
// </synopsis>
 
// <motivation>
// This class makes it possible to access an image in a FITS file.
// </motivation>
 
// <example>
// <srcblock>
//  // Define the object which also opens the file.
//  // The (float) array starts at offset 2880.
//  TiledFileAccess tfa ("fits.file", 2880, IPosition(2,512,512),
//                       IPosition(2,512,1), TpFloat);
//  // Get all the data.
//  Array<Float> data = tfa.getFloat (Slicer(IPosition(2,0,0), tfa.shape()));
// </srcblock>
// </example>
 
// # <todo asof="$DATE:$">
// # A List of bugs, limitations, extensions or planned refinements.
// # </todo>
 
class TiledFileAccess {
 public:
  // Create a TiledFileAccess object.
  // The data is assumed to be in local canonical format
  // (thus big endian on e.g. SUN and little endian on e.g. PC).
  // The TSMOption determines how the file is accessed.
  TiledFileAccess(const String& fileName, Int64 fileOffset, const IPosition& shape,
                  const IPosition& tileShape, DataType dataType, const TSMOption& = TSMOption(),
                  Bool writable = False);
 
  // Create a TiledFileAccess object.
  // The endian format of the data is explicitly given.
  TiledFileAccess(const String& fileName, Int64 fileOffset, const IPosition& shape,
                  const IPosition& tileShape, DataType dataType, const TSMOption&, Bool writable,
                  Bool bigEndian);
 
  ~TiledFileAccess();
 
  // Forbid copy constructor.
  TiledFileAccess(const TiledFileAccess&) = delete;
 
  // Forbid assignment.
  TiledFileAccess& operator=(const TiledFileAccess&) = delete;
 
  // Is the file writable?
  Bool isWritable() const { return itsWritable; }
 
  DataType dataType() const { return itsDataType; }
 
  // Get part of the array.
  // The Array object is resized if needed.
  // <group>
  Array<Bool> getBool(const Slicer& section);
  Array<uChar> getUChar(const Slicer& section);
  Array<Short> getShort(const Slicer& section);
  Array<Int> getInt(const Slicer& section);
  Array<Float> getFloat(const Slicer& section);
  Array<Double> getDouble(const Slicer& section);
  Array<Complex> getComplex(const Slicer& section);
  Array<DComplex> getDComplex(const Slicer& section);
  void get(Array<Bool>&, const Slicer& section);
  void get(Array<uChar>&, const Slicer& section);
  void get(Array<Short>&, const Slicer& section);
  void get(Array<Int>&, const Slicer& section);
  void get(Array<Float>&, const Slicer& section);
  void get(Array<Double>&, const Slicer& section);
  void get(Array<Complex>&, const Slicer& section);
  void get(Array<DComplex>&, const Slicer& section);
  // </group>
 
  // Get the array and scale/offset the data using the given values.
  // It is meant for FITS, so for now they can only be used for TpUChar, TpShort
  // or TpInt TiledFileAccess objects.
  // A deleteValue is set to a NaN without being scaled.
  // <group>
  Array<Float> getFloat(const Slicer& section, Float scale, Float offset, uChar deleteValue,
                        Bool examineForDeleteValues = True);
  Array<Float> getFloat(const Slicer& section, Float scale, Float offset, Short deleteValue,
                        Bool examineForDeleteValues = True);
  Array<Float> getFloat(const Slicer& section, Float scale, Float offset, Int deleteValue,
                        Bool examineForDeleteValues = True);
  void get(Array<Float>&, const Slicer& section, Float scale, Float offset, uChar deleteValue,
           Bool examineForDeleteValues = True);
  void get(Array<Float>&, const Slicer& section, Float scale, Float offset, Short deleteValue,
           Bool examineForDeleteValues = True);
  void get(Array<Float>&, const Slicer& section, Float scale, Float offset, Int deleteValue,
           Bool examineForDeleteValues = True);
  // </group>
 
  // Put part of the array.
  // <group>
  void put(const Array<Bool>&, const Slicer& section);
  void put(const Array<uChar>&, const Slicer& section);
  void put(const Array<Short>&, const Slicer& section);
  void put(const Array<Int>&, const Slicer& section);
  void put(const Array<Float>&, const Slicer& section);
  void put(const Array<Double>&, const Slicer& section);
  void put(const Array<Complex>&, const Slicer& section);
  void put(const Array<DComplex>&, const Slicer& section);
  // </group>
 
  // Flush the cache.
  void flush() { itsCube->flushCache(); }
 
  // Empty the cache.
  // It will flush the cache as needed and remove all buckets from it
  // resulting in a possibly large drop in memory used.
  // It'll also clear the <src>userSetCache_p</src> flag.
  void clearCache() { itsCube->emptyCache(); }
 
  // Show the cache statistics.
  void showCacheStatistics(ostream& os) const { itsCube->showCacheStatistics(os); }
 
  // Get the shape of the array.
  const IPosition& shape() const { return itsCube->cubeShape(); }
 
  // Get the shape of the tiles.
  const IPosition& tileShape() const { return itsCube->tileShape(); }
 
  // Set the maximum cache size (in bytes).
  // 0 means no maximum.
  void setMaximumCacheSize(uInt64 nbytes);
 
  // Get the maximum cache size (in bytes).
  uInt64 maximumCacheSize() const;
 
  // Get the current cache size (in buckets).
  uInt cacheSize() const { return itsCube->cacheSize(); }
 
  // Set the cache size using the given access pattern.
  // <group>
  void setCacheSize(const IPosition& sliceShape, const IPosition& axisPath,
                    Bool forceSmaller = True) {
    itsCube->setCacheSize(sliceShape, IPosition(), IPosition(), axisPath, forceSmaller, True);
  }
  void setCacheSize(const IPosition& sliceShape, const IPosition& windowStart,
                    const IPosition& windowLength, const IPosition& axisPath,
                    Bool forceSmaller = True) {
    itsCube->setCacheSize(sliceShape, windowStart, windowLength, axisPath, forceSmaller, True);
  }
  // </group>
 
  // Set the cache size for accessing the data.
  // When the give cache size exceeds the maximum cache size with more
  // than 10%, the maximum cache size is used instead.
  // <br>When forceSmaller is False, the cache is not resized when the
  // new size is smaller.
  void setCacheSize(uInt nbuckets, Bool forceSmaller = True) {
    itsCube->setCacheSize(nbuckets, forceSmaller, True);
  }
 
  // Make a tile shape from the array shape to fit as closely as possible
  // the number of pixels in the tile.
  static IPosition makeTileShape(const IPosition& arrayShape, uInt nrPixelsPerTile = 32768);
 
 private:
  TSMCube* itsCube;
  TiledFileHelper* itsTSM;
  uInt itsLocalPixelSize;
  Bool itsWritable;
  DataType itsDataType;
};
 
}  // namespace casacore
 
#endif