Detailed Description

template<typename T, uint_t fieldFSize>
class walberla::field::FieldIterator< T, fieldFSize >

Iterator over a 4D array, stored linearized in memory.

The iterator is created by specifying a field slice. It supports neighbor access and knows its own x,y,z,f coordinates.

This is NOT a lightweight object as most iterators are, since it has to store begin and end for each of the four dimensions plus some data to speed up the calculation of current coordinate.

The FieldIterator itself cannot change the position it points to. The ForwardFieldIterator and ReverseFieldIterator are derived from this class and provide the according operators. When writing a function that calculates something in a specific cell should take a FieldIterator as argument ( not Forward- or ReverseFieldIterators ) so that it can be called with both Forward and Reverse iterators. For this case there is also a more generic way: see walberla::field::FieldPointer

Implementation

#include <FieldIterator.h>

Inheritance diagram for walberla::field::FieldIterator< T, fieldFSize >:

Public Types
using	iterator_category = std::forward_iterator_tag

using	value_type = T

using	difference_type = std::ptrdiff_t

using	pointer = T *

using	reference = T &

using	FieldType = Field< typename std::remove_const< T >::type, fieldFSize >

Public Member Functions
Copy Operations
	FieldIterator (const FieldIterator< T, fieldFSize > &other)

FieldIterator< T, fieldFSize > &	operator= (const FieldIterator< T, fieldFSize > &other)
	Assignment operator. More...

Operators
bool	operator== (const FieldIterator &it) const
	Equal operator. More...

bool	operator!= (const FieldIterator &it) const
	Unequal operator. More...

	operator const FieldIterator< const T, fieldFSize > & () const

Access Functions
T &	operator* () const

T *	operator-> () const

T &	getF (cell_idx_t cf) const
	For beginXYZ iterators, one often needs a specific f Assumes that iterator stands at f==0. More...

T &	getF (uint_t cf) const
	Equivalent to neighbor(cell_idx_t) see above. More...

T &	operator[] (cell_idx_t cf) const

T &	operator[] (uint_t cf) const

T &	neighbor (stencil::Direction d, cell_idx_t cf=0) const
	Neighbor access relative to current position. More...

T &	neighbor (stencil::Direction d, uint_t cf) const
	uint_t variant of above function More...

T &	neighbor (cell_idx_t cx, cell_idx_t cy, cell_idx_t cz, cell_idx_t cf=0) const
	Neighbor access relative to current position. More...

T &	neighbor (cell_idx_t cx, cell_idx_t cy, cell_idx_t cz, uint_t cf) const
	Neighbor variant that takes unsigned int as f parameter, needed since the stencil toIdx() is an unsigned int. More...

Coordinates of current position
cell_idx_t	x () const
	In order to get x(), y(), z(), f() function as fast a possible, no if clause for the layout was introduced. More...

cell_idx_t	y () const

cell_idx_t	z () const

cell_idx_t	f () const

Cell	cell () const

Utility Functions
void	print (std::ostream &str) const

const FieldType *	getField () const

Static Public Attributes
static const uint_t	F_SIZE = fieldFSize

Constructor/Destructor
class	Field< typename std::remove_const< T >::type, fieldFSize >

T *	lineBegin_
	Points to begin of fastest coordinate line. More...

T *	linePtr_
	Point to current element. More...

T *	lineEnd_
	Points to end of current line. More...

cell_idx_t	cur_ [3]
	In the following vectors [0] is the slowest and [3] the fastest coordinate Current values of the coordinates, forth coordinate implicitly stored in linePtr_ and if needed written to fastestCoord_. More...

uint_t	skips_ [4]
	Number of elements to skip when coordinate wraps around. More...

uint_t	sizes_ [4]
	Size of each coordinate. More...

const FieldType *	f_
	Field where iterator belongs to. More...

cell_idx_t	xBegin_
	Following offset values are only used in functions x(),y(),z(),f() More...

cell_idx_t	yBegin_

cell_idx_t	zBegin_

cell_idx_t	fBegin_

	FieldIterator ()
	Constructs an end iterator, which is represented by NULL pointers. More...

	FieldIterator (const FieldType *f, cell_idx_t xBeg, cell_idx_t yBeg, cell_idx_t zBeg, cell_idx_t fBeg, uint_t xSize, uint_t ySize, uint_t zSize, uint_t fSize, bool forward)

void	incrementLine ()
	Increments the slower 3 coordinates, if innermost coordinate is at end. More...

void	decrementLine ()
	Decrements the slower 3 coordinates, if innermost coordinate is at beginning. More...

Speeding up x(), y(), z(), f() functions
The following members are only needed to speed up the x(), y(), z(), f() functions. In order to get x(), y(), z(), f() function as fast a possible, no if clause for the layout was introduced. Instead there are the cur[XYZF]_ members, that point to the cur_ array. The cur_ array does not store the fastest coordinate, because it is implicitly stored in (linePtr_ - lineBegin_). If it would be stored explicitly there would have to be an extra update operation in operator++() , which should be as fast as possible. The curX_ or curF_ pointer points to the fastestCoord_ member, which always has to be updated before curX_ or curF_ is dereferenced.
cell_idx_t	fastestCoord_

cell_idx_t *	curX_

cell_idx_t *	curY_

cell_idx_t *	curZ_

cell_idx_t *	curF_

void	initCoordinateAccessOptimizationPointers ()
	Initializes pointers required for the optimized x(),y(),z(),f() functions See documentation of fastestCoord_, curX_, curY_, curZ_ and curF_. More...

Member Typedef Documentation

◆ difference_type

template<typename T , uint_t fieldFSize>

using walberla::field::FieldIterator< T, fieldFSize >::difference_type = std::ptrdiff_t

◆ FieldType

template<typename T , uint_t fieldFSize>

using walberla::field::FieldIterator< T, fieldFSize >::FieldType = Field<typename std::remove_const<T>::type, fieldFSize>

◆ iterator_category

template<typename T , uint_t fieldFSize>

using walberla::field::FieldIterator< T, fieldFSize >::iterator_category = std::forward_iterator_tag

◆ pointer

template<typename T , uint_t fieldFSize>

using walberla::field::FieldIterator< T, fieldFSize >::pointer = T*

◆ reference

template<typename T , uint_t fieldFSize>

using walberla::field::FieldIterator< T, fieldFSize >::reference = T&

◆ value_type

template<typename T , uint_t fieldFSize>

using walberla::field::FieldIterator< T, fieldFSize >::value_type = T

Constructor & Destructor Documentation

◆ FieldIterator() [1/3]

template<typename T , uint_t fieldFSize>

walberla::field::FieldIterator< T, fieldFSize >::FieldIterator ( const FieldIterator< T, fieldFSize > & other )

◆ FieldIterator() [2/3]

template<typename T , uint_t fs>

walberla::field::FieldIterator< T, fs >::FieldIterator

explicitprotected

Constructs an end iterator, which is represented by NULL pointers.

◆ FieldIterator() [3/3]

template<typename T , uint_t fieldFSize>

walberla::field::FieldIterator< T, fieldFSize >::FieldIterator	(	const FieldType *	f,
		cell_idx_t	xBeg,
		cell_idx_t	yBeg,
		cell_idx_t	zBeg,
		cell_idx_t	fBeg,
		uint_t	xSize,
		uint_t	ySize,
		uint_t	zSize,
		uint_t	fSize,
		bool	forward
	)

explicitprotected

Member Function Documentation

◆ cell()

template<typename T , uint_t fs>

Cell walberla::field::FieldIterator< T, fs >::cell

inline

◆ decrementLine()

template<typename T , uint_t fs>

void walberla::field::FieldIterator< T, fs >::decrementLine

inlineprotected

Decrements the slower 3 coordinates, if innermost coordinate is at beginning.

◆ f()

template<typename T , uint_t fs>

cell_idx_t walberla::field::FieldIterator< T, fs >::f

inline

◆ getF() [1/2]

template<typename T , uint_t fs>

T & walberla::field::FieldIterator< T, fs >::getF ( cell_idx_t cf ) const

inline

For beginXYZ iterators, one often needs a specific f Assumes that iterator stands at f==0.

Parameters

cf	Delta for f

◆ getF() [2/2]

template<typename T , uint_t fs>

T & walberla::field::FieldIterator< T, fs >::getF ( uint_t cf ) const

inline

Equivalent to neighbor(cell_idx_t) see above.

Takes an uint_t instead a cell_idx_t, since stencil::toIndex() returns uint_t

Parameters

cf	Delta for f

◆ getField()

template<typename T , uint_t fieldFSize>

const FieldType* walberla::field::FieldIterator< T, fieldFSize >::getField ( ) const

inline

◆ incrementLine()

template<typename T , uint_t fs>

void walberla::field::FieldIterator< T, fs >::incrementLine

inlineprotected

Increments the slower 3 coordinates, if innermost coordinate is at end.

◆ initCoordinateAccessOptimizationPointers()

template<typename T , uint_t fs>

void walberla::field::FieldIterator< T, fs >::initCoordinateAccessOptimizationPointers

protected

Initializes pointers required for the optimized x(),y(),z(),f() functions See documentation of fastestCoord_, curX_, curY_, curZ_ and curF_.

◆ neighbor() [1/4]

template<typename T , uint_t fs>

T & walberla::field::FieldIterator< T, fs >::neighbor	(	cell_idx_t	cx,
		cell_idx_t	cy,
		cell_idx_t	cz,
		cell_idx_t	cf = `0`
	)		const

inline

Neighbor access relative to current position.

Parameters

cx	Delta for x
cy	Delta for y
cz	Delta for z
cf	Delta for f

◆ neighbor() [2/4]

template<typename T , uint_t fs>

T & walberla::field::FieldIterator< T, fs >::neighbor	(	cell_idx_t	cx,
		cell_idx_t	cy,
		cell_idx_t	cz,
		uint_t	cf
	)		const

inline

Neighbor variant that takes unsigned int as f parameter, needed since the stencil toIdx() is an unsigned int.

Parameters

cx	Delta for x
cy	Delta for y
cz	Delta for z
cf	Delta for f

◆ neighbor() [3/4]

template<typename T , uint_t fs>

T & walberla::field::FieldIterator< T, fs >::neighbor	(	stencil::Direction	d,
		cell_idx_t	cf = `0`
	)		const

inline

Neighbor access relative to current position.

Parameters

d	Direction enumeration which defines deltas for x,y,z
cf	Delta for f

◆ neighbor() [4/4]

template<typename T , uint_t fs>

T & walberla::field::FieldIterator< T, fs >::neighbor	(	stencil::Direction	d,
		uint_t	cf
	)		const

inline

uint_t variant of above function

Parameters

d	Direction enumeration which defines deltas for x,y,z
cf	Delta for f

◆ operator const FieldIterator< const T, fieldFSize > &()

template<typename T , uint_t fieldFSize>

walberla::field::FieldIterator< T, fieldFSize >::operator const FieldIterator< const T, fieldFSize > & ( ) const

inline

◆ operator!=()

template<typename T , uint_t fieldFSize>

bool walberla::field::FieldIterator< T, fs >::operator!= ( const FieldIterator< T, fieldFSize > & it ) const

inline

Unequal operator.

◆ operator*()

template<typename T , uint_t fieldFSize>

T& walberla::field::FieldIterator< T, fieldFSize >::operator* ( ) const

inline

◆ operator->()

template<typename T , uint_t fieldFSize>

T* walberla::field::FieldIterator< T, fieldFSize >::operator-> ( ) const

inline

◆ operator=()

template<typename T , uint_t fieldFSize>

FieldIterator< T, fs > & walberla::field::FieldIterator< T, fs >::operator= ( const FieldIterator< T, fieldFSize > & other )

Assignment operator.

Required for pointer member cur*_

◆ operator==()

template<typename T , uint_t fieldFSize>

bool walberla::field::FieldIterator< T, fs >::operator== ( const FieldIterator< T, fieldFSize > & it ) const

inline

Equal operator.

Test equality only by comparing the internal pointer

Returns: true if both iterators are equal

◆ operator[]() [1/2]

template<typename T , uint_t fieldFSize>

T& walberla::field::FieldIterator< T, fieldFSize >::operator[] ( cell_idx_t cf ) const

inline

◆ operator[]() [2/2]

template<typename T , uint_t fieldFSize>

T& walberla::field::FieldIterator< T, fieldFSize >::operator[] ( uint_t cf ) const

inline

◆ print()

template<typename T , uint_t fs>

void walberla::field::FieldIterator< T, fs >::print ( std::ostream & str ) const

inline

◆ x()

template<typename T , uint_t fs>

cell_idx_t walberla::field::FieldIterator< T, fs >::x

inline

In order to get x(), y(), z(), f() function as fast a possible, no if clause for the layout was introduced.

Instead there are the cur[XYZF]_ members, that point to the cur_ array. The cur_ array does not store the fastest coordinate, because it is implicitly stored in (linePtr_ - lineBegin_). If it would be stored explicitly there would have to be an extra update operation in operator++() , which should be as fast as possible. The curX_ or curF_ pointer points to the fastestCoord_ member, which always has to be updated before curX_ or curF_ is dereferenced.

◆ y()

template<typename T , uint_t fs>

cell_idx_t walberla::field::FieldIterator< T, fs >::y

inline

◆ z()

template<typename T , uint_t fs>

cell_idx_t walberla::field::FieldIterator< T, fs >::z

inline

Friends And Related Function Documentation

◆ Field< typename std::remove_const< T >::type, fieldFSize >

template<typename T , uint_t fieldFSize>

friend class Field< typename std::remove_const< T >::type, fieldFSize >

friend

Member Data Documentation

◆ cur_

template<typename T , uint_t fieldFSize>

cell_idx_t walberla::field::FieldIterator< T, fieldFSize >::cur_[3]

protected

In the following vectors [0] is the slowest and [3] the fastest coordinate Current values of the coordinates, forth coordinate implicitly stored in linePtr_ and if needed written to fastestCoord_.

◆ curF_

template<typename T , uint_t fieldFSize>

cell_idx_t* walberla::field::FieldIterator< T, fieldFSize >::curF_

protected

◆ curX_

template<typename T , uint_t fieldFSize>

cell_idx_t* walberla::field::FieldIterator< T, fieldFSize >::curX_

protected

◆ curY_

template<typename T , uint_t fieldFSize>

cell_idx_t* walberla::field::FieldIterator< T, fieldFSize >::curY_

protected

◆ curZ_

template<typename T , uint_t fieldFSize>

cell_idx_t* walberla::field::FieldIterator< T, fieldFSize >::curZ_

protected

◆ f_

template<typename T , uint_t fieldFSize>

const FieldType* walberla::field::FieldIterator< T, fieldFSize >::f_

protected

Field where iterator belongs to.

◆ F_SIZE

template<typename T , uint_t fieldFSize>

const uint_t walberla::field::FieldIterator< T, fieldFSize >::F_SIZE = fieldFSize

static

◆ fastestCoord_

template<typename T , uint_t fieldFSize>

cell_idx_t walberla::field::FieldIterator< T, fieldFSize >::fastestCoord_

mutableprotected

◆ fBegin_

template<typename T , uint_t fieldFSize>

cell_idx_t walberla::field::FieldIterator< T, fieldFSize >::fBegin_

protected

◆ lineBegin_

template<typename T , uint_t fieldFSize>

T* walberla::field::FieldIterator< T, fieldFSize >::lineBegin_

protected

Points to begin of fastest coordinate line.

◆ lineEnd_

template<typename T , uint_t fieldFSize>

T* walberla::field::FieldIterator< T, fieldFSize >::lineEnd_

protected

Points to end of current line.

◆ linePtr_

template<typename T , uint_t fieldFSize>

T* walberla::field::FieldIterator< T, fieldFSize >::linePtr_

protected

Point to current element.

◆ sizes_

template<typename T , uint_t fieldFSize>

uint_t walberla::field::FieldIterator< T, fieldFSize >::sizes_[4]

protected

Size of each coordinate.

◆ skips_

template<typename T , uint_t fieldFSize>

uint_t walberla::field::FieldIterator< T, fieldFSize >::skips_[4]

protected

Number of elements to skip when coordinate wraps around.

◆ xBegin_

template<typename T , uint_t fieldFSize>

cell_idx_t walberla::field::FieldIterator< T, fieldFSize >::xBegin_

protected

Following offset values are only used in functions x(),y(),z(),f()

◆ yBegin_

template<typename T , uint_t fieldFSize>

cell_idx_t walberla::field::FieldIterator< T, fieldFSize >::yBegin_

protected

◆ zBegin_

template<typename T , uint_t fieldFSize>

cell_idx_t walberla::field::FieldIterator< T, fieldFSize >::zBegin_

protected

The documentation for this class was generated from the following files:

/builds/administration/walberla-website/walberla/src/field/iterators/FieldIterator.h
/builds/administration/walberla-website/walberla/src/field/iterators/FieldIterator.impl.h

Detailed Description

template<typename T, uint_t fieldFSize> class walberla::field::FieldIterator< T, fieldFSize >

Public Types

Public Member Functions

Static Public Attributes

Constructor/Destructor

Speeding up x(), y(), z(), f() functions

Member Typedef Documentation

◆ difference_type

◆ FieldType

◆ iterator_category

◆ pointer

◆ reference

◆ value_type

Constructor & Destructor Documentation

◆ FieldIterator() [1/3]

◆ FieldIterator() [2/3]

◆ FieldIterator() [3/3]

Member Function Documentation

◆ cell()

◆ decrementLine()

◆ f()

◆ getF() [1/2]

◆ getF() [2/2]

◆ getField()

◆ incrementLine()

◆ initCoordinateAccessOptimizationPointers()

◆ neighbor() [1/4]

◆ neighbor() [2/4]

◆ neighbor() [3/4]

◆ neighbor() [4/4]

◆ operator const FieldIterator< const T, fieldFSize > &()

◆ operator!=()

◆ operator*()

◆ operator->()

◆ operator=()

◆ operator==()

◆ operator[]() [1/2]

◆ operator[]() [2/2]

◆ print()

◆ x()

◆ y()

◆ z()

Friends And Related Function Documentation

◆ Field< typename std::remove_const< T >::type, fieldFSize >

Member Data Documentation

◆ cur_

◆ curF_

◆ curX_

◆ curY_

◆ curZ_

◆ f_

◆ F_SIZE

◆ fastestCoord_

◆ fBegin_

◆ lineBegin_

◆ lineEnd_

◆ linePtr_

◆ sizes_

◆ skips_

◆ xBegin_

◆ yBegin_

◆ zBegin_

template<typename T, uint_t fieldFSize>
class walberla::field::FieldIterator< T, fieldFSize >