lcrtrel::LCRTRelations Class Reference

Base class that provides run time (user) extensions and relation between objects. More...

#include <LCRTRelations.h>

Inheritance diagram for lcrtrel::LCRTRelations:

List of all members.

Public Member Functions
template<class V >
V::ext_type	ext ()
	Provides access to an extension object - the type and ownership is defined by the class V which should be a subtype of LCExtension, LCOwnedExtension, LCExtensionVector, LCExtensionList,.
template<class V >
const V::ext_type	ext () const
template<class V >
V::rel_type	rel ()
	Provides read access to relations - the object types and their connectivity are defined by the class V which has to be a subtype of either LC1To1Relation, LC1ToNRelation or LCNToNRelation.
Protected Member Functions
template<class V >
V::ptr &	ptr () const
	Returns the reference to the pointer to the extension/relation object.
Friends
template<class R >
void	set_relation (typename R::from::obj_ptr f, typename R::to::obj_ptr t)
	Set the 1-to-1 relation between two objects - prexisting inconsistent relations involving the two objects are deleted to enforce a consistent set of from-to relations.
template<class R >
void	unset_relation (typename R::from::obj_ptr f)
	Unset the 1-to-1 relation from f.
template<class R >
void	add_relation (typename R::from::obj_ptr f, typename R::to::obj_ptr t)
	Add a link from f to t to an N-to-N relation ship.
template<class R >
void	remove_relation (typename R::from::obj_ptr f, typename R::to::obj_ptr t)
	Remove the link from from f to t from the N-to-N relation ship.
template<class R >
void	remove_relations (typename R::from::obj_ptr f)
	Removes all relations from the given object.
template<class R >
void	merge_relations (typename R::from::obj_ptr f1, typename R::from::obj_ptr f2)
	Merge the relations from f2 to f1 - after this call f1 will hold all the relations and f2 will be empty.

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Detailed Description

Base class that provides run time (user) extensions and relation between objects.

Every subclass object of LCRTRelations (and thus LCObbject) will automatically have the following functionality:

• extension of the object with arbitrary (even non-LCObject) classes
• extension of single objects or vectors, lists of objects
• optionally ownership is taken for extension objects (memory management)
• relations to other subclasses of LCRTRelations:
  • one to one
  • one to many
  • many to many

The described functionality is provided through the two templated member functions:
ext<class V>()
rel<class V>()
the class V is a user defined so called traits class, that uniquely tags the extension/relationship and defines the types of the objects involved.
For extensions users have to subclass one of the following classes:
LCExtension, LCOwnedExtension, LCIntExtension, LCFloatExtension,
LCExtensionVector, LCExtensionList, LCOwnedExtensionVector, LCOwnedExtensionList.
For example the following defines a user extension of a vector of strings that are owned by the object (i.e. deleted when the object is deleted):

struct ParticleIDs : LCOwnedExtensionVector<ParticleIDs, std::string> {};
   (note: the first template parameter has to be the class itself !)

This extension can then be used anywhere in the following code for all LCObjects, e.g.:

MCParticle* mcp = dynamic_cast<MCParticle*>( mcpcol->getElementAt(i) ) ;
mcp->ext<ParticleIDs>()->push_back( new std::string("charged") ) ;
mcp->ext<ParticleIDs>()->push_back( new std::string("hadron") ) ;
mcp->ext<ParticleIDs>()->push_back( new std::string("pion") ) ;

and be read out again:

ParticleIDs::ext_type pidv = mcp->ext<ParticleIDs>() ;
for( ParticleIDs::const_iterator ipid = pidv->begin() ; ipid != pidv->end(); ++ipid){
   std::cout << **ipid << ", " ;
}

Similarily the following defines a one to many relationship between Tracks and Clusters:

struct TrkCluLink : LC1ToNRelation<TrkCluLink,Track,Cluster> {} ;

Relations are allways biderectional, i.e. there is a from and a to side. They can then be set and modified with the following functions:
set_relation(), unset_relation(), add_relation(),
remove_relation(), remove_relations(), merge_relations().
For example:

Track* trk = dynamic_cast<Track*> ( trkcol->getElementAt(j) ) ;
//...
Cluster* clu = dynamic_cast<Cluster*> ( clucol->getElementAt(k) ) ;
add_relation<TrkCluLink>( trk ,clu );

The many side can then be read out with a const_iterator and the one side with a normal pointer:

Track* trk = clu->rel<TrkCluLink::from>() ;
//...
TrkCluLink::to::rel_type clulist = trk->rel<TrkCluLink::to>() ;
for( TrkCluLink::to::const_iterator iclu = clulist->begin() ; iclu != clulist->end() ; ++iclu ){
  Cluster* clu = *iclu ; // iterator is of type pointer to container element
  std::cout << " assigned cluster with E = " << clu->getEnergy() << std::endl ;
}

More examples can be found in $LCIO/src/cpp/src/EXAMPLES/lcrtrelations.cc.

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Member Function Documentation

template<class V >

V::ext_type lcrtrel::LCRTRelations::ext

(

)

[inline]

Provides access to an extension object - the type and ownership is defined by the class V which should be a subtype of LCExtension, LCOwnedExtension, LCExtensionVector, LCExtensionList,.

..

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Friends And Related Function Documentation

template<class R >

void set_relation	(	typename R::from::obj_ptr	f,
		typename R::to::obj_ptr	t
	)			[friend]

Set the 1-to-1 relation between two objects - prexisting inconsistent relations involving the two objects are deleted to enforce a consistent set of from-to relations.

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

• LCRTRelations.h