StoredRange< iterator_type, object_type > Class Template Reference

#include <stored_range.h>

List of all members.

Public Types
typedef std::vector < object_type > ::const_iterator	const_iterator
Public Member Functions
	StoredRange (const unsigned int grainsize=1000)
	StoredRange (const iterator_type &first, const iterator_type &last, const unsigned int grainsize=1000)
	StoredRange (const StoredRange< iterator_type, object_type > &er)
	StoredRange (StoredRange< iterator_type, object_type > &r, Threads::split)
StoredRange< iterator_type, object_type > &	reset (const iterator_type &first, const iterator_type &last)
StoredRange< iterator_type, object_type > &	reset ()
const_iterator	begin () const
const_iterator	end () const
unsigned int	first_idx () const
unsigned int	last_idx () const
unsigned int	grainsize () const
void	grainsize (const unsigned int &gs)
unsigned int	size () const
bool	empty () const
bool	is_divisible () const
Private Attributes
const_iterator	_end
const_iterator	_begin
unsigned int	_last
unsigned int	_first
unsigned int	_grainsize
std::vector< object_type >	_objs

---

Detailed Description

template<typename iterator_type, typename object_type>
class StoredRange< iterator_type, object_type >

The StoredRange class defined a contiguous, divisible set of objects This class is used primarily as the argument to function objects. The range can then be subdivided into a number of "tasks" which can be executed in parallel. This concept is central to the Threading Building Blocks template library which can optionally be used by libMesh to implement shared-memory parallelism.

The implementation takes a user-provided object range and packs it into a contiguous vector which can then be subdivided efficiently. A first-cut implementation using raw element iterators incurred simply too much overhead by using the predicated iterators, specifically operations such as advancing such iterators has a cost proportional to the amount the iterator is advanced. Hence in this implementation the user-provided range is packed into a vector.

Author:

Benjamin S. Kirk, 2008.

Definition at line 50 of file stored_range.h.

---

Member Typedef Documentation

template<typename iterator_type , typename object_type >

typedef std::vector<object_type>::const_iterator StoredRange< iterator_type, object_type >::const_iterator

Allows an StoredRange to behave like an STL container.

Definition at line 56 of file stored_range.h.

---

Constructor & Destructor Documentation

template<typename iterator_type , typename object_type >

StoredRange< iterator_type, object_type >::StoredRange

(

const unsigned int

grainsize = 1000

)

[inline]

Constructor. Optionally takes the grainsize parameter, which is the smallest chunk the range may be broken into for parallel execution.

Definition at line 63 of file stored_range.h.

                                                    :
  _grainsize(grainsize)
  {}

template<typename iterator_type , typename object_type >

StoredRange< iterator_type, object_type >::StoredRange	(	const iterator_type &	first,
		const iterator_type &	last,
		const unsigned int	grainsize = 1000
	)			[inline]

Constructor. Takes the beginning and end of the range. Optionally takes the grainsize parameter, which is the smallest chunk the range may be broken into for parallel execution.

Definition at line 73 of file stored_range.h.

References StoredRange< iterator_type, object_type >::reset().

                                                    :
  _grainsize(grainsize)
  {
    this->reset(first, last);
  }

template<typename iterator_type , typename object_type >

StoredRange< iterator_type, object_type >::StoredRange

(

const StoredRange< iterator_type, object_type > &

er

)

[inline]

Copy constructor. The StoredRange can be copied into subranges for parallel execution. In this way the initial StoredRange can be thought of as the root of a binary tree. The root element is the only element which interacts with the user. It takes a specified range of objects and packs it into a contiguous vector which can be split efficiently. However, there is no need for the child ranges to contain this vector, so long as the parent outlives the children. So we implement the copy constructor to specifically omit the _objs vector.

Definition at line 94 of file stored_range.h.

00094                                                                 :
00095     _end(er._end), 
00096     _begin(er._begin),
00097     _last(er._last),
00098     _first(er._first),
00099     _grainsize(er._grainsize)
00100   {
00101     // specifically, do *not* copy the vector
00102   }
    

template<typename iterator_type , typename object_type >

StoredRange< iterator_type, object_type >::StoredRange	(	StoredRange< iterator_type, object_type > &	r,
		Threads::split
	)			[inline]

Splits the range r. The first half of the range is left in place, the second half of the range is placed in *this.

Definition at line 109 of file stored_range.h.

References StoredRange< iterator_type, object_type >::_begin, StoredRange< iterator_type, object_type >::_end, StoredRange< iterator_type, object_type >::_first, and StoredRange< iterator_type, object_type >::_last.

                                                                         : 
    _end(r._end),
    _begin(r._begin),
    _last(r._last),
    _first(r._first),
    _grainsize(r._grainsize)
  {
    const_iterator
      beginning = r._begin,
      ending    = r._end,
      middle    = beginning + std::distance(beginning, ending)/2u;
    
    r._end = _begin = middle;

    unsigned int
      first = r._first,
      last  = r._last,
      half  = first + (last-first)/2u;

    r._last = _first = half;
  }

---

Member Function Documentation

template<typename iterator_type , typename object_type >

const_iterator StoredRange< iterator_type, object_type >::begin

(

)

const [inline]

Beginning of the range.

Definition at line 175 of file stored_range.h.

References StoredRange< iterator_type, object_type >::_begin.

Referenced by System::ProjectVector::operator()(), PatchRecoveryErrorEstimator::EstimateError::operator()(), and SparsityPattern::Build::operator()().

{ return _begin; }  

template<typename iterator_type , typename object_type >

bool StoredRange< iterator_type, object_type >::empty

(

)

const [inline]

Returns true if the range is empty.

Definition at line 215 of file stored_range.h.

References StoredRange< iterator_type, object_type >::_begin, and StoredRange< iterator_type, object_type >::_end.

{ return (_begin == _end); }

template<typename iterator_type , typename object_type >

const_iterator StoredRange< iterator_type, object_type >::end

(

)

const [inline]

End of the range.

Definition at line 180 of file stored_range.h.

References StoredRange< iterator_type, object_type >::_end.

Referenced by System::ProjectVector::operator()(), PatchRecoveryErrorEstimator::EstimateError::operator()(), and SparsityPattern::Build::operator()().

{ return _end; }

template<typename iterator_type , typename object_type >

unsigned int StoredRange< iterator_type, object_type >::first_idx

(

)

const [inline]

Index in the stored vector of the first object.

Definition at line 185 of file stored_range.h.

References StoredRange< iterator_type, object_type >::_first.

{ return _first; }

template<typename iterator_type , typename object_type >

void StoredRange< iterator_type, object_type >::grainsize

(

const unsigned int &

gs

)

[inline]

Set the grain size.

Definition at line 201 of file stored_range.h.

References StoredRange< iterator_type, object_type >::_grainsize.

{_grainsize = gs;}

template<typename iterator_type , typename object_type >

unsigned int StoredRange< iterator_type, object_type >::grainsize

(

)

const [inline]

The grain size for the range. The range will be subdivided into subranges not to exceed the grain size.

Definition at line 196 of file stored_range.h.

References StoredRange< iterator_type, object_type >::_grainsize.

Referenced by StoredRange< iterator_type, object_type >::is_divisible().

{return _grainsize;}

template<typename iterator_type , typename object_type >

bool StoredRange< iterator_type, object_type >::is_divisible

(

)

const [inline]

Returns true if the range can be subdivided.

Definition at line 220 of file stored_range.h.

References StoredRange< iterator_type, object_type >::_begin, StoredRange< iterator_type, object_type >::_end, and StoredRange< iterator_type, object_type >::grainsize().

{ return this->grainsize() < static_cast<unsigned int>(std::distance(_begin, _end)); }

template<typename iterator_type , typename object_type >

unsigned int StoredRange< iterator_type, object_type >::last_idx

(

)

const [inline]

Index in the stored vector of the last object.

Definition at line 190 of file stored_range.h.

References StoredRange< iterator_type, object_type >::_last.

{ return _last; }

template<typename iterator_type , typename object_type >

StoredRange<iterator_type, object_type>& StoredRange< iterator_type, object_type >::reset

(

)

[inline]

Resets the range to the last specified range. This method only exists for efficiency -- it is more efficient to set the range to its previous value without rebuilding the underlying vector. Returns a reference to itself for convenience, so functions expecting a StoredRange<> can be passed e.g. foo.reset().

Definition at line 161 of file stored_range.h.

References StoredRange< iterator_type, object_type >::_begin, StoredRange< iterator_type, object_type >::_end, StoredRange< iterator_type, object_type >::_first, StoredRange< iterator_type, object_type >::_last, and StoredRange< iterator_type, object_type >::_objs.

Referenced by StoredRange< iterator_type, object_type >::StoredRange().

  {
    _begin = _objs.begin();
    _end   = _objs.end();

    _first = 0;
    _last  = _objs.size();

    return *this;
  }

template<typename iterator_type , typename object_type >

StoredRange<iterator_type, object_type>& StoredRange< iterator_type, object_type >::reset	(	const iterator_type &	first,
		const iterator_type &	last
	)			[inline]

Resets the StoredRange to contain [first,last). Returns a reference to itself for convenience, so functions expecting a StoredRange<> can be passed e.g. foo.reset(begin,end).

Definition at line 137 of file stored_range.h.

References StoredRange< iterator_type, object_type >::_begin, StoredRange< iterator_type, object_type >::_end, StoredRange< iterator_type, object_type >::_first, StoredRange< iterator_type, object_type >::_last, and StoredRange< iterator_type, object_type >::_objs.

Referenced by DofMap::create_dof_constraints().

  {
    _objs.clear();

    for (iterator_type it=first; it!=last; ++it)
      _objs.push_back(*it);
    
    _begin = _objs.begin();
    _end   = _objs.end();

    _first = 0;
    _last  = _objs.size();
    
    return *this;
  }

template<typename iterator_type , typename object_type >

unsigned int StoredRange< iterator_type, object_type >::size

(

)

const [inline]

Returns:

the size of the range.

Definition at line 206 of file stored_range.h.

References StoredRange< iterator_type, object_type >::_begin, and StoredRange< iterator_type, object_type >::_end.

{ return std::distance(_begin, _end); }

---

Member Data Documentation

template<typename iterator_type , typename object_type >

const_iterator StoredRange< iterator_type, object_type >::_begin [private]

Definition at line 225 of file stored_range.h.

Referenced by StoredRange< iterator_type, object_type >::begin(), StoredRange< iterator_type, object_type >::empty(), StoredRange< iterator_type, object_type >::is_divisible(), StoredRange< iterator_type, object_type >::reset(), StoredRange< iterator_type, object_type >::size(), and StoredRange< iterator_type, object_type >::StoredRange().

template<typename iterator_type , typename object_type >

const_iterator StoredRange< iterator_type, object_type >::_end [private]

Definition at line 224 of file stored_range.h.

Referenced by StoredRange< iterator_type, object_type >::empty(), StoredRange< iterator_type, object_type >::end(), StoredRange< iterator_type, object_type >::is_divisible(), StoredRange< iterator_type, object_type >::reset(), StoredRange< iterator_type, object_type >::size(), and StoredRange< iterator_type, object_type >::StoredRange().

template<typename iterator_type , typename object_type >

unsigned int StoredRange< iterator_type, object_type >::_first [private]

Definition at line 227 of file stored_range.h.

Referenced by StoredRange< iterator_type, object_type >::first_idx(), StoredRange< iterator_type, object_type >::reset(), and StoredRange< iterator_type, object_type >::StoredRange().

template<typename iterator_type , typename object_type >

unsigned int StoredRange< iterator_type, object_type >::_grainsize [private]

Definition at line 228 of file stored_range.h.

Referenced by StoredRange< iterator_type, object_type >::grainsize().

template<typename iterator_type , typename object_type >

unsigned int StoredRange< iterator_type, object_type >::_last [private]

Definition at line 226 of file stored_range.h.

Referenced by StoredRange< iterator_type, object_type >::last_idx(), StoredRange< iterator_type, object_type >::reset(), and StoredRange< iterator_type, object_type >::StoredRange().

template<typename iterator_type , typename object_type >

std::vector<object_type> StoredRange< iterator_type, object_type >::_objs [private]

Definition at line 229 of file stored_range.h.

Referenced by StoredRange< iterator_type, object_type >::reset().

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

• stored_range.h