Gaudi Framework, version v21r8
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GaudiHandle< T > Class Template Reference

Handle to be used in lieu of naked pointers to gaudis. More...

#include <GaudiKernel/GaudiHandle.h>

Inheritance diagram for GaudiHandle< T >:

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List of all members.

Public Member Functions

 GaudiHandle (const GaudiHandle &other)
 Copy constructor needed for correct ref-counting.
GaudiHandle & operator= (const GaudiHandle &other)
 Assignment operator for correct ref-counting.
StatusCode retrieve () const
 Retrieve the component.
StatusCode release () const
 Release the component.
 operator bool () const
 For testing if handle has component.
T & operator* ()
T * operator-> ()
T & operator* () const
T * operator-> () const
std::string getDefaultType ()
 Helper function to get default type string from the class type.
std::string getDefaultName ()

Protected Member Functions

 GaudiHandle (const std::string &myTypeAndName, const std::string &myComponentType, const std::string &myParentName)
virtual StatusCode retrieve (T *&) const =0
 Retrieve the component.
virtual StatusCode release (T *comp) const
 Release the component.

Private Member Functions

void setDefaultTypeAndName ()
 Helper function to set default name and type.
void setDefaultType ()
 Helper function to set default type from the class type T.
bool getObject () const
 Load the pointer to the component.
void assertObject () const
 Load the pointer to the component.

Private Attributes

T * m_pObject

Detailed Description

template<class T>
class GaudiHandle< T >

Handle to be used in lieu of naked pointers to gaudis.

This allows better control through the framework of gaudi loading and usage. T is the type of the component interface (or concrete class).

Author:
Martin.Woudstra@cern.ch

Definition at line 158 of file GaudiHandle.h.

Constructor & Destructor Documentation

template<class T>
GaudiHandle< T >::GaudiHandle ( const std::string &  myTypeAndName,
const std::string &  myComponentType,
const std::string &  myParentName 
) [inline, protected]

Definition at line 163 of file GaudiHandle.h.

00165     : GaudiHandleBase(myTypeAndName, myComponentType, myParentName), m_pObject(0)
00166   {}

template<class T>
GaudiHandle< T >::GaudiHandle ( const GaudiHandle< T > &  other  )  [inline]

Copy constructor needed for correct ref-counting.

Definition at line 170 of file GaudiHandle.h.

00171     : GaudiHandleBase( other ) {
00172     m_pObject = other.m_pObject;
00173     if ( m_pObject ) m_pObject->addRef();
00174   }

Member Function Documentation

template<class T>
GaudiHandle& GaudiHandle< T >::operator= ( const GaudiHandle< T > &  other  )  [inline]

Assignment operator for correct ref-counting.

Definition at line 177 of file GaudiHandle.h.

00177                                                      {
00178     GaudiHandleBase::operator=( other );
00179     // release any current tool
00180     release().ignore();
00181     m_pObject = other.m_pObject;
00182     // update ref-counting
00183     if ( m_pObject ) m_pObject->addRef();
00184     return *this;
00185   }

template<class T>
StatusCode GaudiHandle< T >::retrieve (  )  const [inline]

Retrieve the component.

Release existing component if needed.

Reimplemented in ServiceHandle< T >, ToolHandle< T >, and ServiceHandle< IToolSvc >.

Definition at line 188 of file GaudiHandle.h.

00188                               { // not really const, because it updates m_pObject
00189     if ( m_pObject && release().isFailure() ) return StatusCode::FAILURE;
00190     if ( retrieve( m_pObject ).isFailure() ) {
00191       m_pObject = 0;
00192       return StatusCode::FAILURE;
00193     }
00194     return StatusCode::SUCCESS;
00195   }

template<class T>
StatusCode GaudiHandle< T >::release (  )  const [inline]

Release the component.

Reimplemented in ToolHandle< T >.

Definition at line 198 of file GaudiHandle.h.

00198                              { // not really const, because it updates m_pObject
00199     if ( m_pObject ) {
00200       StatusCode sc = release( m_pObject );
00201       m_pObject = 0;
00202       return sc;
00203     }
00204     return StatusCode::SUCCESS;
00205   }

template<class T>
GaudiHandle< T >::operator bool (  )  const [inline]

For testing if handle has component.

Does retrieve() if needed. If this returns false, the component could not be retrieved.

Definition at line 209 of file GaudiHandle.h.

00209                         { // not really const, because it may update m_pObject
00210     return getObject();
00211   }

template<class T>
T& GaudiHandle< T >::operator* (  )  [inline]

Definition at line 213 of file GaudiHandle.h.

00213                  {
00214     assertObject();
00215     return *m_pObject;
00216   }

template<class T>
T* GaudiHandle< T >::operator-> (  )  [inline]

Definition at line 218 of file GaudiHandle.h.

00218                   {
00219     assertObject();
00220     return m_pObject;
00221   }

template<class T>
T& GaudiHandle< T >::operator* (  )  const [inline]

Definition at line 223 of file GaudiHandle.h.

00223                        { // not really const, because it may update m_pObject
00224     assertObject();
00225     return *m_pObject;
00226   }

template<class T>
T* GaudiHandle< T >::operator-> (  )  const [inline]

Definition at line 228 of file GaudiHandle.h.

00228                         { // not really const, because it may update m_pObject
00229     assertObject();
00230     return m_pObject;
00231   }

template<class T>
std::string GaudiHandle< T >::getDefaultType (  )  [inline]

Helper function to get default type string from the class type.

Definition at line 234 of file GaudiHandle.h.

00234                              {
00235     return System::typeinfoName( typeid(T) );
00236   }

template<class T>
std::string GaudiHandle< T >::getDefaultName (  )  [inline]

Definition at line 238 of file GaudiHandle.h.

00238                              {
00239     std::string defName = GaudiHandleBase::type();
00240     if ( defName.empty() ) defName = getDefaultType();
00241     return defName;
00242   }

template<class T>
virtual StatusCode GaudiHandle< T >::retrieve ( T *&   )  const [protected, pure virtual]

Retrieve the component.

To be implemented by the derived class. It will pass the pointer

Implemented in ServiceHandle< T >, ToolHandle< T >, and ServiceHandle< IToolSvc >.

template<class T>
virtual StatusCode GaudiHandle< T >::release ( T *  comp  )  const [inline, protected, virtual]

Release the component.

Default implementation calls release() on the component. Can be overridden by the derived class if something else if needed.

Reimplemented in ToolHandle< T >.

Definition at line 250 of file GaudiHandle.h.

00250                                               { // not really const, because it updates m_pObject
00251     comp->release();
00252     return StatusCode::SUCCESS;
00253   }

template<class T>
void GaudiHandle< T >::setDefaultTypeAndName (  )  [inline, private]

Helper function to set default name and type.

Definition at line 257 of file GaudiHandle.h.

00257                                {
00258     const std::string& myType = getDefaultType();
00259     GaudiHandleBase::setTypeAndName(myType+'/'+myType);
00260   }

template<class T>
void GaudiHandle< T >::setDefaultType (  )  [inline, private]

Helper function to set default type from the class type T.

Definition at line 263 of file GaudiHandle.h.

00263                         {
00264     GaudiHandleBase::setTypeAndName( getDefaultType() );
00265   }

template<class T>
bool GaudiHandle< T >::getObject (  )  const [inline, private]

Load the pointer to the component.

Do a retrieve if needed

Definition at line 268 of file GaudiHandle.h.

00268                          { // not really const, because it may update m_pObject
00269     return m_pObject || retrieve().isSuccess();
00270   }

template<class T>
void GaudiHandle< T >::assertObject (  )  const [inline, private]

Load the pointer to the component.

Do a retrieve if needed. Throw an exception if retrieval fails.

Definition at line 274 of file GaudiHandle.h.

00274                             { // not really const, because it may update m_pObject
00275     if ( !getObject() ) {
00276       throw GaudiException("Failed to retrieve " + componentType() + ": " + typeAndName(),
00277                            componentType() + " retrieve", StatusCode::FAILURE);
00278     }
00279   }

Member Data Documentation

template<class T>
T* GaudiHandle< T >::m_pObject [mutable, private]

Definition at line 283 of file GaudiHandle.h.

The documentation for this class was generated from the following file:
Generated at Wed Mar 17 18:17:18 2010 for Gaudi Framework, version v21r8 by Doxygen version 1.5.6 written by Dimitri van Heesch, © 1997-2004