A Lattice that can be used for temporary storage. More...

#include <VisImagingWeight.h>

Inheritance diagram for casacore::TempLattice< T >:

Public Member Functions
	TempLattice ()
	The default constructor creates a TempLattice containing a default ArrayLattice object. More...

	TempLattice (const TiledShape &shape, Int maxMemoryInMB=-1)
	Create a TempLattice of the specified shape. More...

	TempLattice (const TiledShape &shape, Double maxMemoryInMB)

	TempLattice (const TempLattice< T > &other)
	The copy constructor uses reference semantics. More...

virtual	~TempLattice ()
	The destructor removes the Lattice from memory and if necessary disk. More...

TempLattice< T > &	operator= (const TempLattice< T > &other)
	The assignment operator with reference semantics. More...

virtual Lattice< T > *	clone () const
	Make a copy of the object (reference semantics). More...

virtual Bool	isPaged () const
	Is the TempLattice paged to disk? More...

virtual Bool	canReferenceArray () const
	Can the lattice data be referenced as an array section? More...

virtual Bool	isWritable () const
	Is the TempLattice writable? It should be. More...

virtual void	flush ()
	Flush the data. More...

virtual void	tempClose ()
	Close the Lattice temporarily (if it is paged to disk). More...

virtual void	reopen ()
	If needed, reopen a temporarily closed TempLattice. More...

virtual IPosition	shape () const
	Return the shape of the Lattice including all degenerate axes. More...

virtual void	set (const T &value)
	Set all of the elements in the Lattice to the given value. More...

virtual void	apply (T(*function)(T))
	Replace every element, x, of the Lattice with the result of f(x). More...

virtual void	apply (T(*function)(const T &))

virtual void	apply (const Functional< T, T > &function)

virtual uInt	advisedMaxPixels () const
	This function returns the recommended maximum number of pixels to include in the cursor of an iterator. More...

virtual IPosition	doNiceCursorShape (uInt maxPixels) const
	Get the best cursor shape. More...

virtual uInt	maximumCacheSize () const
	Maximum size - not necessarily all used. More...

virtual void	setMaximumCacheSize (uInt howManyPixels)
	Set the maximum (allowed) cache size as indicated. More...

virtual void	setCacheSizeFromPath (const IPosition &sliceShape, const IPosition &windowStart, const IPosition &windowLength, const IPosition &axisPath)
	Set the cache size as to "fit" the indicated path. More...

virtual void	setCacheSizeInTiles (uInt howManyTiles)
	Set the actual cache size for this Array to be be big enough for the indicated number of tiles. More...

virtual void	clearCache ()
	Clears and frees up the caches, but the maximum allowed cache size is unchanged from when setCacheSize was called. More...

virtual void	showCacheStatistics (ostream &os) const
	Report on cache success. More...

virtual T	getAt (const IPosition &where) const
	Get or put a single element in the lattice. More...

virtual void	putAt (const T &value, const IPosition &where)
	Put the value of a single element. More...

virtual Bool	ok () const
	Check class internals - used for debugging. More...

virtual LatticeIterInterface< T > *	makeIter (const LatticeNavigator &navigator, Bool useRef) const
	This function is used by the LatticeIterator class to generate an iterator of the correct type for this Lattice. More...

virtual Bool	doGetSlice (Array< T > &buffer, const Slicer &section)
	Do the actual getting of an array of values. More...

virtual void	doPutSlice (const Array< T > &sourceBuffer, const IPosition &where, const IPosition &stride)
	Do the actual getting of an array of values. More...

Public Member Functions inherited from casacore::Lattice< T >
virtual	~Lattice ()
	a virtual destructor is needed so that it will use the actual destructor in the derived class More...

virtual DataType	dataType () const
	Get the data type of the lattice. More...

T	operator() (const IPosition &where) const
	Return the value of the single element located at the argument IPosition. More...

Bool	get (COWPtr< Array< T > > &buffer, Bool removeDegenerateAxes=False) const
	Functions which extract an Array of values from a Lattice. More...

Bool	getSlice (COWPtr< Array< T > > &buffer, const Slicer &section, Bool removeDegenerateAxes=False) const

Bool	getSlice (COWPtr< Array< T > > &buffer, const IPosition &start, const IPosition &shape, Bool removeDegenerateAxes=False) const

Bool	getSlice (COWPtr< Array< T > > &buffer, const IPosition &start, const IPosition &shape, const IPosition &stride, Bool removeDegenerateAxes=False) const

Bool	get (Array< T > &buffer, Bool removeDegenerateAxes=False)

Bool	getSlice (Array< T > &buffer, const Slicer &section, Bool removeDegenerateAxes=False)

Bool	getSlice (Array< T > &buffer, const IPosition &start, const IPosition &shape, Bool removeDegenerateAxes=False)

Bool	getSlice (Array< T > &buffer, const IPosition &start, const IPosition &shape, const IPosition &stride, Bool removeDegenerateAxes=False)

Array< T >	get (Bool removeDegenerateAxes=False) const

Array< T >	getSlice (const Slicer &section, Bool removeDegenerateAxes=False) const

Array< T >	getSlice (const IPosition &start, const IPosition &shape, Bool removeDegenerateAxes=False) const

Array< T >	getSlice (const IPosition &start, const IPosition &shape, const IPosition &stride, Bool removeDegenerateAxes=False) const

void	putSlice (const Array< T > &sourceBuffer, const IPosition &where, const IPosition &stride)
	A function which places an Array of values within this instance of the Lattice at the location specified by the IPosition "where", incrementing by "stride". More...

void	putSlice (const Array< T > &sourceBuffer, const IPosition &where)

void	put (const Array< T > &sourceBuffer)

void	operator+= (const Lattice< T > &other)
	Add, subtract, multiple, or divide by another Lattice. More...

void	operator-= (const Lattice< T > &other)

void	operator*= (const Lattice< T > &other)

void	operator/= (const Lattice< T > &other)

virtual void	copyData (const Lattice< T > &from)
	Copy the data from the given lattice to this one. More...

virtual void	copyDataTo (Lattice< T > &to) const
	Copy the data from this lattice to the given lattice. More...

Public Member Functions inherited from casacore::LatticeBase
virtual	~LatticeBase ()
	A virtual destructor is needed so that it will use the actual destructor in the derived class. More...

virtual String	imageType () const
	Get the image type (returns name of derived class). More...

virtual Bool	isPersistent () const
	Is the lattice persistent and can it be loaded by other processes as well? That is the case for a PagedArray or PagedImage and for an ImageExpr which does not use transient lattices or regions. More...

virtual void	save (const String &fileName) const
	Save the image in an AipsIO file with the given name. More...

virtual Bool	lock (FileLocker::LockType, uInt nattempts)
	It is strongly recommended to use class LatticeLocker to handle lattice locking. More...

virtual void	unlock ()

virtual Bool	hasLock (FileLocker::LockType) const

virtual void	resync ()
	Resynchronize the Lattice object with the lattice file. More...

virtual String	name (Bool stripPath=False) const
	Return the name of the current Lattice object. More...

virtual uInt	ndim () const
	Return the number of axes in this Lattice. More...

virtual size_t	nelements () const
	Return the total number of elements in this Lattice. More...

size_t	size () const

Bool	conform (const LatticeBase &other) const
	Return a value of "True" if this instance of Lattice and 'other' have the same shape, otherwise returns a value of "False". More...

virtual LELCoordinates	lelCoordinates () const
	Return the coordinates of the lattice. More...

IPosition	niceCursorShape (uInt maxPixels) const
	Returns a recommended cursor shape for iterating through all the pixels in the Lattice. More...

IPosition	niceCursorShape () const

Private Attributes
CountedPtr< TempLatticeImpl< T > >	itsImpl

Additional Inherited Members
Protected Member Functions inherited from casacore::Lattice< T >
	Lattice ()
	Define default constructor to satisfy compiler. More...

virtual void	handleMath (const Lattice< T > &from, int oper)
	Handle the Math operators (+=, -=, *=, /=). More...

virtual void	handleMathTo (Lattice< T > &to, int oper) const

	Lattice (const Lattice< T > &)
	Copy constructor and assignment can only be used by derived classes. More...

Lattice< T > &	operator= (const Lattice< T > &)

template<>
void	handleMathTo (Lattice< Bool > &, int) const

Protected Member Functions inherited from casacore::LatticeBase
	LatticeBase ()
	Define default constructor to be used by derived classes. More...

	LatticeBase (const LatticeBase &)
	Copy constructor and assignment can only be used by derived classes. More...

LatticeBase &	operator= (const LatticeBase &)

void	throwBoolMath () const
	Throw an exception for arithmetic on a Bool Lattice. More...

Detailed Description

template<class T>
class casacore::TempLattice< T >

A Lattice that can be used for temporary storage.

Intended use:

Public interface

Review Status

Reviewed By:: Peter Barnes
Date Reviewed:: 1999/10/30
Test programs:: tTempLattice

Prerequisite

Etymology

A TempLattice disappears from both memory and disk when it goes out of scope. Hence it is only useful for temporary storage of data.

Synopsis

Lattice classes are designed to allow the memory-efficient handling of large amounts of data. But they can also used with much smaller arrays. With large amounts of data the PagedArray class should be used, as this will store the data on disk and efficiently access specified portions of the data on request. With small amounts of data the ArrayLattice class should be used as all the data is always in memory avoiding the I/O associated with PagedArrays.

Applications often cannot predict until run time whether they will be dealing with a large or small amount of data. So the use of a PagedArray or an ArrayLattice cannot be made until the size of the arrays are known. TempLattice makes this decision given the size of the Array. To help in making a good choice the TempLattice class also examines how much memory the operating system has (using an aipsrc variable) and compares it with the size of the requested Array.

The algorithm currently used is: create an ArrayLattice if the size of the array is less than a quarter of the total system memory; otherwise a PagedArray is created. The PagedArray is stored in the current working directory and given a unique name that contains the string "pagedArray". This pagedArray will be deleted once the TempLattice goes out of scope. So unlike PagedArrays which can be made to exist longer than the time they are used by a process, the PagedArrays created by the TempLattice class are always scratch arrays.

It is possible to temporarily close a TempLattice, which only takes effect when it is created as a PagedArray. In this way it is possible to reduce the number of open files in case a lot of TempLattice objects are used. A temporarily closed TempLattice will be reopened automatically when needed. It can also be reopened explicitly.

You can force the TempLattice to be disk based by setting the memory argument in the constructors to 0

TempLattice is implemented using TempLatticeImpl for reasons explained in that class.

Example

// Create a temporary lattice and initialize to 0.
TempLattice<Float> myLat (IPosition(2,1024,1024));
myLat.set (0.);
// Temporarily close the lattice.
myLat.tempClose();
// Do an operation, which will automatically reopen the lattice.
myLat.set (1.);
// Note that the destructor deletes the table (if the TempLattice
// was created on disk).

Motivation

I needed a temporary Lattice when converting the Convolver class to using Lattices. This was to store the Transfer function.

Template Type Argument Requirements (T)

Any type that can be used by the Lattices can also be used by this class.

Definition at line 41 of file VisImagingWeight.h.

Constructor & Destructor Documentation

template<class T>

casacore::TempLattice< T >::TempLattice ( )

inline

The default constructor creates a TempLattice containing a default ArrayLattice object.

Definition at line 137 of file TempLattice.h.

template<class T>

casacore::TempLattice< T >::TempLattice	(	const TiledShape &	shape,
		Int	maxMemoryInMB = `-1`
	)

inlineexplicit

Create a TempLattice of the specified shape.

You can specify how much memory the Lattice can consume before it becomes disk based by giving a non-negative value to the maxMemoryInMB argument. Otherwise it will assume it can use up to 25% of the memory on your machine as defined in aipsrc (this algorithm may change). Setting maxMemoryInMB to zero will force the lattice to disk.

Definition at line 147 of file TempLattice.h.

template<class T>

casacore::TempLattice< T >::TempLattice	(	const TiledShape &	shape,
		Double	maxMemoryInMB
	)

inline

Definition at line 149 of file TempLattice.h.

template<class T>

casacore::TempLattice< T >::TempLattice ( const TempLattice< T > & other )

inline

The copy constructor uses reference semantics.

ie modifying data in the copied TempLattice also modifies the data in the original TempLattice. Passing by value doesn't make sense, because it may require the creation of a temporary (but possibly huge) file on disk.

Definition at line 157 of file TempLattice.h.

template<class T>

virtual casacore::TempLattice< T >::~TempLattice ( )

virtual

The destructor removes the Lattice from memory and if necessary disk.

Member Function Documentation

template<class T>

virtual uInt casacore::TempLattice< T >::advisedMaxPixels ( ) const

virtual

This function returns the recommended maximum number of pixels to include in the cursor of an iterator.

Reimplemented from casacore::Lattice< T >.

template<class T>

virtual void casacore::TempLattice< T >::apply ( T(*)(T) function )

virtual

Replace every element, x, of the Lattice with the result of f(x).

You must pass in the address of the function – so the function must be declared and defined in the scope of your program. All versions of apply require a function that accepts a single argument of type T (the Lattice template type) and return a result of the same type. The first apply expects a function with an argument passed by value; the second expects the argument to be passed by const reference; the third requires an instance of the class Functional<T,T>. The first form ought to run faster for the built-in types, which may be an issue for large Lattices stored in memory, where disk access is not an issue.

Reimplemented from casacore::Lattice< T >.

template<class T>

virtual void casacore::TempLattice< T >::apply ( T(*)(const T &) function )

virtual

Reimplemented from casacore::Lattice< T >.

template<class T>

virtual void casacore::TempLattice< T >::apply ( const Functional< T, T > & function )

virtual

Reimplemented from casacore::Lattice< T >.

template<class T>

virtual Bool casacore::TempLattice< T >::canReferenceArray ( ) const

virtual

Can the lattice data be referenced as an array section?

Reimplemented from casacore::LatticeBase.

template<class T>

virtual void casacore::TempLattice< T >::clearCache ( )

virtual

Clears and frees up the caches, but the maximum allowed cache size is unchanged from when setCacheSize was called.

Reimplemented from casacore::LatticeBase.

template<class T>

virtual Lattice<T>* casacore::TempLattice< T >::clone ( ) const

virtual

Make a copy of the object (reference semantics).

Implements casacore::Lattice< T >.

template<class T>

virtual Bool casacore::TempLattice< T >::doGetSlice	(	Array< T > &	buffer,
		const Slicer &	section
	)

virtual

Do the actual getting of an array of values.

Implements casacore::Lattice< T >.

template<class T>

virtual IPosition casacore::TempLattice< T >::doNiceCursorShape ( uInt maxPixels ) const

virtual

Get the best cursor shape.

Reimplemented from casacore::LatticeBase.

template<class T>

virtual void casacore::TempLattice< T >::doPutSlice	(	const Array< T > &	sourceBuffer,
		const IPosition &	where,
		const IPosition &	stride
	)

virtual

Do the actual getting of an array of values.

Implements casacore::Lattice< T >.

template<class T>

virtual void casacore::TempLattice< T >::flush ( )

virtual

Flush the data.

Reimplemented from casacore::LatticeBase.

template<class T>

virtual T casacore::TempLattice< T >::getAt ( const IPosition & where ) const

virtual

Get or put a single element in the lattice.

Note that Lattice::operator() can also be used to get a single element.

Reimplemented from casacore::Lattice< T >.

template<class T>

virtual Bool casacore::TempLattice< T >::isPaged ( ) const

virtual

Is the TempLattice paged to disk?

Reimplemented from casacore::LatticeBase.

template<class T>

virtual Bool casacore::TempLattice< T >::isWritable ( ) const

virtual

Is the TempLattice writable? It should be.

Reimplemented from casacore::LatticeBase.

template<class T>

virtual LatticeIterInterface<T>* casacore::TempLattice< T >::makeIter	(	const LatticeNavigator &	navigator,
		Bool	useRef
	)		const

virtual

This function is used by the LatticeIterator class to generate an iterator of the correct type for this Lattice.

Not recommended for general use.

Reimplemented from casacore::Lattice< T >.

template<class T>

virtual uInt casacore::TempLattice< T >::maximumCacheSize ( ) const

virtual

Maximum size - not necessarily all used.

In pixels.

Reimplemented from casacore::LatticeBase.

template<class T>

virtual Bool casacore::TempLattice< T >::ok ( ) const

virtual

Check class internals - used for debugging.

Should always return True

Reimplemented from casacore::LatticeBase.

template<class T>

TempLattice<T>& casacore::TempLattice< T >::operator= ( const TempLattice< T > & other )

inline

The assignment operator with reference semantics.

As with the copy constructor assigning by value does not make sense.

Definition at line 165 of file TempLattice.h.

template<class T>

virtual void casacore::TempLattice< T >::putAt	(	const T &	value,
		const IPosition &	where
	)

virtual

Put the value of a single element.

The default implementation uses putSlice.

Reimplemented from casacore::Lattice< T >.

template<class T>

virtual void casacore::TempLattice< T >::reopen ( )

virtual

If needed, reopen a temporarily closed TempLattice.

Reimplemented from casacore::LatticeBase.

template<class T>

virtual void casacore::TempLattice< T >::set ( const T & value )

virtual

Set all of the elements in the Lattice to the given value.

Reimplemented from casacore::Lattice< T >.

template<class T>

virtual void casacore::TempLattice< T >::setCacheSizeFromPath	(	const IPosition &	sliceShape,
		const IPosition &	windowStart,
		const IPosition &	windowLength,
		const IPosition &	axisPath
	)

virtual

Set the cache size as to "fit" the indicated path.

Reimplemented from casacore::LatticeBase.

template<class T>

virtual void casacore::TempLattice< T >::setCacheSizeInTiles ( uInt howManyTiles )

virtual

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.

Reimplemented from casacore::LatticeBase.

template<class T>

virtual void casacore::TempLattice< T >::setMaximumCacheSize ( uInt howManyPixels )

virtual

Set the maximum (allowed) cache size as indicated.

Reimplemented from casacore::LatticeBase.

template<class T>

virtual IPosition casacore::TempLattice< T >::shape ( ) const

virtual

Return the shape of the Lattice including all degenerate axes.

(ie. axes with a length of one)

Implements casacore::LatticeBase.