Class SBCContainerIndexer#

template <class ObjectType, class HashMap, class Vector>

This template class is used to efficiently index objects. More...

#include <SBCContainerIndexer.hpp>

Classes#

Type	Name
class	const_iterator
class	const_reverse_iterator
class	iterator
class	reverse_iterator

Public Functions#

Type	Name
	SBCContainerIndexer () Creates an indexer.
	SBCContainerIndexer (unsigned int initialSize) Creates an indexer with a default pre-allocated size.
	SBCContainerIndexer (std::set< ObjectType > & objectSet) Indexes a set of objects.
	SBCContainerIndexer (std::vector< ObjectType > & objectVector) Indexes a vector of objects.
	SBCContainerIndexer (const SBCContainerIndexer & indexer) Copy constructor.
	SBCContainerIndexer (SBCContainerIndexer && indexer) Move constructor.
iterator	begin () Returns an iterator that points to the beginning of the indexer.
const_iterator	begin () const Returns an iterator that points to the beginning of the indexer.
void	clear () Clears the indexer.
bool	empty () const Returns true if and only if the indexer is empty.
iterator	end () Returns an iterator that points to the end of the indexer.
const_iterator	end () const Returns an iterator that points to the end of the indexer.
unsigned int	eraseIndex (unsigned int objectIndex) Erases object objectIndex from the indexer.
unsigned int	eraseObject (const ObjectType & object) Erases the object from the indexer.
unsigned int	getIndex (const ObjectType & object) const Returns the index associated to the object .
bool	getIndex (const ObjectType & object, unsigned int & index) const Returns the index associated to the object .
ObjectType	getObject (unsigned int index) const Returns the object associated to the index .
bool	hasIndex (const ObjectType & object) const Returns true if the object has an index.
unsigned int	insert (unsigned int i, const ObjectType & object) Inserts an object in the indexer at position `i` if possible, and returns the index of the object.
SBCContainerIndexer &	operator= (const SBCContainerIndexer & indexer) Copy assignment.
SBCContainerIndexer &	operator= (SBCContainerIndexer && indexer) Move assignment.
ObjectType	operator[] (unsigned int index) const Returns the object associated to the index .
unsigned int	pop_back () Adds an object in the indexer and returns the index of the object.
void	print () const Prints some debugging information.
unsigned int	push_back (const ObjectType & object) Adds an object in the indexer if possible, and returns the index of the object.
reverse_iterator	rbegin () Returns a reverse iterator that points to the reverse beginning of the indexer.
const_reverse_iterator	rbegin () const Returns a reverse iterator that points to the reverse beginning of the indexer.
reverse_iterator	rend () Returns a reverse iterator that points to the reverse end of the indexer.
const_reverse_iterator	rend () const Returns a reverse iterator that points to the reverse end of the indexer.
unsigned int	size () const Returns the number of indexed objects.
virtual	~SBCContainerIndexer () Destructs the indexer.

Protected Attributes#

Type	Name
HashMap *	indexMap The hash map.
Vector *	objectVector The object vector.

Detailed Description#

Fast indexing of objects is required in SAMSON because objects may operate on lists of other objects (e.g. a collision detection solver operates on a list of structural model components). An indexer provides a way to map the set of n objects to a set of ordered indices, from 0 to n-1, which can then be used for fast access to information associated to the mapped objects.

SBCContainerIndexer makes it possible to index values contiguously. Precisely, it is guaranteed that values are always indexed by integers in . To achieve this, when an object with index is removed from the index, the index of object becomes . SBCContainerIndexer may be used to index values compactly and dynamically.

// create atoms

unsigned int nAtoms = 100;
SBAtom** atomArray = new SBAtom*[nAtoms];

for (unsigned int i = 0; i<nAtoms; i++) atomArray[i] = new SBAtom();

// index atoms

SBIndexer<SBAtom*>* atomIndexer = new SBIndexer<SBAtom*>();

for (unsigned int i = 0; i<nAtoms; i++)
    atomIndexer->push_back(atomArray[i]);

// print indices

for (unsigned int i = 0; i<nAtoms; i++) {

    if (atomIndexer->hasIndex(atomArray[i]))
        std::cout << "  Atom " << atomArray[i] <<
        " -> " << atomIndexer->getIndex(atomArray[i]) << ".\n";
    else
        std::cout << "  Atom " << atomArray[i] << " -> no index.\n";

}

// erase atomArray[9] from the index

atomIndexer->eraseObject(atomArray[9]);

// print indices
// atomArray[9] has no index
// atomArray[99] now has index 9

for (unsigned int i = 0; i<nAtoms; i++) {

    if (atomIndexer->hasIndex(atomArray[i]))
        std::cout << "  Atom " << atomArray[i] <<
        " -> " << atomIndexer->getIndex(atomArray[i]) << ".\n";
    else
        std::cout << "  Atom " << atomArray[i] << " -> no index.\n";

}

// erase atom with index 2

atomIndexer->eraseIndex(2);

// print indices
// atomArray[9] has no index
// atomArray[99] now has index 9
// atomArray[2] has no index
// atomArray[98] has index 2

for (unsigned int i = 0; i<nAtoms; i++) {

    if (atomIndexer->hasIndex(atomArray[i]))
        std::cout << "  Atom " << atomArray[i] <<
        " -> " << atomIndexer->getIndex(atomArray[i]) << ".\n";
    else
        std::cout << "  Atom " << atomArray[i] << " -> no index.\n";

}

Internally, SBCContainerIndexer uses a hash map (by default SBCContainerHashMap) to assign indices and a vector (by default SBCContainerVector) to store objects. As a result, retrieving indices takes an almost constant time, while retrieving objects takes constant time.

Short name: SBIndexer

Public Functions Documentation#

function SBCContainerIndexer [1/6]#

Creates an indexer.

SBCContainerIndexer::SBCContainerIndexer ()

function SBCContainerIndexer [2/6]#

Creates an indexer with a default pre-allocated size.

SBCContainerIndexer::SBCContainerIndexer (
    unsigned int initialSize
)

function SBCContainerIndexer [3/6]#

Indexes a set of objects.

SBCContainerIndexer::SBCContainerIndexer (
    std::set< ObjectType > & objectSet
)

function SBCContainerIndexer [4/6]#

Indexes a vector of objects.

SBCContainerIndexer::SBCContainerIndexer (
    std::vector< ObjectType > & objectVector
)

function SBCContainerIndexer [5/6]#

Copy constructor.

SBCContainerIndexer::SBCContainerIndexer (
    const SBCContainerIndexer & indexer
)

function SBCContainerIndexer [6/6]#

Move constructor.

SBCContainerIndexer::SBCContainerIndexer (
    SBCContainerIndexer && indexer
)

function begin [1/2]#

Returns an iterator that points to the beginning of the indexer.

iterator SBCContainerIndexer::begin ()

function begin [2/2]#

Returns an iterator that points to the beginning of the indexer.

const_iterator SBCContainerIndexer::begin () const

function clear#

Clears the indexer.

void SBCContainerIndexer::clear ()

function empty#

Returns true if and only if the indexer is empty.

bool SBCContainerIndexer::empty () const

function end [1/2]#

Returns an iterator that points to the end of the indexer.

iterator SBCContainerIndexer::end ()

function end [2/2]#

Returns an iterator that points to the end of the indexer.

const_iterator SBCContainerIndexer::end () const

function eraseIndex#

Erases object objectIndex from the indexer.

unsigned int SBCContainerIndexer::eraseIndex (
    unsigned int objectIndex
)

The function returns an unsigned int with the following meaning:

if the object was not present in the index, the returned value is the number of indexed objects.
else, the returned value is the index of the object that was removed, in [0, size-1].

Note that these two returned values coincide when the client (unsuccessfully) attempts to erase object with index size.

function eraseObject#

Erases the object from the indexer.

unsigned int SBCContainerIndexer::eraseObject (
    const ObjectType & object
)

The function returns an unsigned int with the following meaning:

if the object was not present in the index, the returned value is the number of indexed objects.
else, the returned value is the index of the object that was removed, in [0, size-1].

Note that these two returned values coincide when the client (unsuccessfully) attempts to erase object with index size.

function getIndex [1/2]#

Returns the index associated to the object .

unsigned int SBCContainerIndexer::getIndex (
    const ObjectType & object
) const

function getIndex [2/2]#

Returns the index associated to the object .

bool SBCContainerIndexer::getIndex (
    const ObjectType & object,
    unsigned int & index
) const

function getObject#

Returns the object associated to the index .

ObjectType SBCContainerIndexer::getObject (
    unsigned int index
) const

function hasIndex#

Returns true if the object has an index.

bool SBCContainerIndexer::hasIndex (
    const ObjectType & object
) const

function insert#

Inserts an object in the indexer at position i if possible, and returns the index of the object.

unsigned int SBCContainerIndexer::insert (
    unsigned int i,
    const ObjectType & object
)

function operator=#

Copy assignment.

SBCContainerIndexer & SBCContainerIndexer::operator= (
    const SBCContainerIndexer & indexer
)

function operator=#

Move assignment.

SBCContainerIndexer & SBCContainerIndexer::operator= (
    SBCContainerIndexer && indexer
)

function operator[]#

Returns the object associated to the index .

ObjectType SBCContainerIndexer::operator[] (
    unsigned int index
) const

function pop_back#

Adds an object in the indexer and returns the index of the object.

unsigned int SBCContainerIndexer::pop_back ()

function print#

Prints some debugging information.

void SBCContainerIndexer::print () const

function push_back#

Adds an object in the indexer if possible, and returns the index of the object.

unsigned int SBCContainerIndexer::push_back (
    const ObjectType & object
)

function rbegin [1/2]#

Returns a reverse iterator that points to the reverse beginning of the indexer.

reverse_iterator SBCContainerIndexer::rbegin ()

function rbegin [2/2]#

Returns a reverse iterator that points to the reverse beginning of the indexer.

const_reverse_iterator SBCContainerIndexer::rbegin () const

function rend [1/2]#

Returns a reverse iterator that points to the reverse end of the indexer.

reverse_iterator SBCContainerIndexer::rend ()

function rend [2/2]#

Returns a reverse iterator that points to the reverse end of the indexer.

const_reverse_iterator SBCContainerIndexer::rend () const

function size#

Returns the number of indexed objects.

unsigned int SBCContainerIndexer::size () const

function ~SBCContainerIndexer#

Destructs the indexer.

virtual SBCContainerIndexer::~SBCContainerIndexer ()

Protected Attributes Documentation#

variable indexMap#

The hash map.

HashMap* indexMap;

variable objectVector#

The object vector.

Vector* objectVector;