LatticeRegion.h

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// # LatticeRegion.h: An optionally strided region in a lattice
// # Copyright (C) 1998,1999,2000,2003
// # 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 LATTICES_LATTICEREGION_H
#define LATTICES_LATTICEREGION_H
 
// # Includes
#include <casacore/casa/aips.h>
#include <casacore/lattices/Lattices/Lattice.h>
#include <casacore/casa/Arrays/Slicer.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// # Forward Declarations
class LCRegion;
 
// <summary>
// An optionally strided  region in a Lattice
// </summary>
 
// <use visibility=local>
 
// <reviewed reviewer="" date="yyyy/mm/dd" tests="" demos="">
// </reviewed>
 
// <prerequisite>
//   <li> <linkto class="LCRegion">LCRegion</linkto>
// </prerequisite>
 
// <synopsis>
// A LatticeRegion is a lattice referencing a subset of another lattice
// by means of a <linkto class="Slicer">Slicer</linkto> object.
// <br>It is useful when only a subset of a lattice needs to be accessed.
// <p>
// When the LatticeRegion is created from a const <src>Lattice</src> object,
// it is not writable, thus it can only be used as an rvalue.
// </synopsis>
 
// <example>
// <srcblock>
// </srcblock>
// </example>
 
// # <todo asof="yyyy/mm/dd">
// # </todo>
 
class LatticeRegion : public Lattice<Bool> {
 public:
  // The default constructor creates a LatticeRegion that is useless for just
  // about everything, except that it can be assigned to with the assignment
  // operator.
  LatticeRegion();
 
  // Create from the given region.
  // The pointer to the parent can be 0.
  LatticeRegion(const LCRegion& region);
 
  // Create from the given region and take over the pointer.
  // This means the user should not delete the region object pointed to,
  // because it will be deleted by the LatticeRegion destructor.
  // The pointer to the parent is set to 0.
  LatticeRegion(LCRegion* region);
 
  // Construct from the given slicer. The lattice shape has to be
  // the lattice shape of the lattice where the region is taken from.
  LatticeRegion(const Slicer& slicer, const IPosition& latticeShape);
 
  // Copy constructor (reference semantics).
  LatticeRegion(const LatticeRegion& other);
 
  virtual ~LatticeRegion();
 
  // Assignment (reference semantics).
  LatticeRegion& operator=(const LatticeRegion& other);
 
  // Make a copy of the object (reference semantics).
  virtual Lattice<Bool>* clone() const;
 
  // Is the LatticeRegion writable?
  virtual Bool isWritable() const;
 
  // Has the region a mask?
  Bool hasMask() const;
 
  // Handle the (un)locking.
  // <group>
  virtual Bool lock(FileLocker::LockType, uInt nattempts);
  virtual void unlock();
  virtual Bool hasLock(FileLocker::LockType) const;
  // </group>
 
  // Resynchronize the PagedArray object with the lattice file.
  // This function is only useful if no read-locking is used, ie.
  // if the table lock option is UserNoReadLocking or AutoNoReadLocking.
  // In that cases the table system does not acquire a read-lock, thus
  // does not synchronize itself automatically.
  virtual void resync();
 
  // Flush the data (but do not unlock).
  virtual void flush();
 
  // Temporarily close the lattice.
  // It will be reopened automatically on the next access.
  virtual void tempClose();
 
  // Explicitly reopen the temporarily closed lattice.
  virtual void reopen();
 
  // Get the LCRegion object describing the region.
  // Note that it does not contain strides, even if this LatticeRegion
  // object was constructed from a Slicer with strides. In that case
  // the region only defines the resulting shape.
  const LCRegion& region() const;
 
  // Get the Slicer object describing the region.
  // Note that it may contain strides.
  const Slicer& slicer() const;
 
  // Returns the shape of the LatticeRegion including all degenerate axes
  // (i.e. axes with a length of one).
  virtual IPosition shape() const;
 
  // Returns the number of axes in this LatticeRegion. This includes all
  // degenerate axes.
  virtual uInt ndim() const;
 
  // Returns the total number of elements in this LatticeRegion.
  virtual size_t nelements() const;
 
  // Check class internals - used for debugging. Should always return True
  virtual Bool ok() const;
 
  // This function is used by the LatticeIterator class to generate an
  // iterator of the correct type for this Lattice. Not recommended
  // for general use.
  virtual LatticeIterInterface<Bool>* makeIter(const LatticeNavigator& navigator,
                                               Bool useRef) const;
 
  // Returns the maximum recommended number of pixels for a cursor.
  // This is the number of pixels in a tile.
  virtual uInt advisedMaxPixels() const;
 
  // Help the user pick a cursor for most efficient access.
  virtual IPosition doNiceCursorShape(uInt maxPixels) const;
 
  // Maximum size - not necessarily all used. In pixels.
  virtual uInt maximumCacheSize() const;
 
  // Set the maximum (allowed) cache size as indicated.
  virtual void setMaximumCacheSize(uInt howManyPixels);
 
  // Set the cache size as to "fit" the indicated path.
  virtual void setCacheSizeFromPath(const IPosition& sliceShape, const IPosition& windowStart,
                                    const IPosition& windowLength, const IPosition& axisPath);
 
  // Set the actual cache size for this Array to be be big enough for the
  // indicated number of tiles. This cache is not shared with PagedArrays
  // in other rows and is always clipped to be less than the maximum value
  // set using the setMaximumCacheSize member function.
  // tiles. Tiles are cached using a first in first out algorithm.
  virtual void setCacheSizeInTiles(uInt howManyTiles);
 
  // Clears and frees up the caches, but the maximum allowed cache size is
  // unchanged from when setCacheSize was called
  virtual void clearCache();
 
  // Report on cache success.
  virtual void showCacheStatistics(std::ostream& os) const;
 
  // The following "put" functions are described in detail in class
  // <linkto class=Lattice>Lattice</linkto>.
  // They'll throw an exception is no mask is available or if
  // the mask is not writable.
  // <group>
  virtual void set(const Bool& value);
  virtual void apply(Bool (*function)(Bool));
  virtual void apply(Bool (*function)(const Bool&));
  virtual void apply(const Functional<Bool, Bool>& function);
  virtual void putAt(const Bool& value, const IPosition& where);
  virtual void copyData(const Lattice<Bool>& from);
  // </group>
 
  // Convert positions to positions in the parent object.
  // <group>
  Slicer convert(const Slicer& slicer) const;
  IPosition convert(const IPosition& position) const;
  // </group>
 
  // Do the actual getting of the mask.
  virtual Bool doGetSlice(Array<Bool>& buffer, const Slicer& section);
 
  // Do the actual putting of the mask. Only possible if region is writable.
  virtual void doPutSlice(const Array<Bool>& sourceBuffer, const IPosition& where,
                          const IPosition& stride);
 
 private:
  LCRegion* itsRegion;
  Slicer itsSlicer;
  Bool itsHasRegionMask;
};
 
inline Bool LatticeRegion::hasMask() const { return itsHasRegionMask; }
inline const LCRegion& LatticeRegion::region() const { return *itsRegion; }
inline const Slicer& LatticeRegion::slicer() const { return itsSlicer; }
 
}  // namespace casacore
 
#endif