Handle class for adding a decoration to an object. More...

#include <WriteDecorHandle.h>

Inheritance diagram for SG::WriteDecorHandle< T, D >:

Collaboration diagram for SG::WriteDecorHandle< T, D >:

Public Types
using	Base = ReadHandle< T >
	Base class. More...

using	accessor_t = SG::AuxElement::Decorator< D >
	Accessor type for aux data. More...

using	reference_type = typename accessor_t::reference_type
	Type referencing an aux data item. More...

using	container_pointer_type = typename accessor_t::container_pointer_type
	Pointer into the vector holding an aux data item. More...

using	span = typename accessor_t::span
	Span of aux data items. More...

Public Member Functions
	WriteDecorHandle (const WriteDecorHandleKey< T > &key)
	Constructor from a WriteDecorHandleKey. More...

	WriteDecorHandle (const WriteDecorHandleKey< T > &key, const EventContext &ctx)
	Constructor from a ReadDecorHandleKey and an explicit event context. More...

	WriteDecorHandle (const WriteDecorHandle &rhs)
	Copy constructor. More...

	WriteDecorHandle (WriteDecorHandle &&rhs)
	Move constructor. More...

	~WriteDecorHandle ()
	Destructor. More...

WriteDecorHandle &	operator= (const WriteDecorHandle &rhs)
	Assignment operator. More...

WriteDecorHandle &	operator= (WriteDecorHandle &&rhs)
	Move operator. More...

bool	isPresent () const
	Is the referenced container present in SG? More...

virtual StatusCode	setProxyDict (IProxyDict *store) override
	Explicitly set the event store. More...

reference_type	operator() (const AuxElement &e)
	Fetch the variable for one element, as a reference. More...

reference_type	operator() (size_t index)
	Fetch the variable for one element, as a reference. More...

template<class POINTER_TYPE = container_pointer_type, typename = std::enable_if_t<!std::is_void_v<POINTER_TYPE> >>
POINTER_TYPE	getDecorationArray ()
	Get a pointer to the start of the auxiliary data array, for the referenced object. More...

span	getDecorationSpan ()
	Get a span over the auxilary data array, for the referenced object. More...

bool	isAvailable ()
	Test to see if this variable exists in the store, for the referenced object. More...

SG::auxid_t	auxid () const
	Return the aux id for this variable. More...

Gaudi::DataHandle::Mode	mode () const
	Return the mode (read/write/update) for this handle. More...

const std::string &	decorKey () const
	Return the name of the decoration alias (CONT.DECOR). More...

Private Member Functions
void	makeDecor (const AuxVectorData *avd)
	Create the decoration if it doesn't actually exist yet. More...

const SG::AuxVectorData *	vectorData (std::true_type)
	Return the referenced object as a `SG::AuxVectorData`. More...

const SG::AuxVectorData *	vectorData (std::false_type)
	Return the referenced object as a `SG::AuxVectorData`. More...

const SG::AuxVectorData *	vectorData ()
	Return the referenced object as a `SG::AuxVectorData`. More...

Private Attributes
std::string	m_decorKey
	Name of the decoration alias: CONT.DECOR. More...

accessor_t	m_acc
	Accessor for the aux data item. More...

bool	m_renounced
	Was this handle renounced? More...

bool	m_decorated
	Have we created the decoration? More...

Detailed Description

template<class T, class D>
class SG::WriteDecorHandle< T, D >

Handle class for adding a decoration to an object.

This (and the corresponding ReadDecorHandle class) allow the scheduler to track dependencies on decorations on objects, in addition to the objects themselves. For example, one algorithm could produce a container C, a second could read C and add a decoration to it C.d, and a third algorithm could read the decoration C.d. This allows the scheduler to know that the third algorithm must be executed after the second completes.

A WriteDecorHandle<T, D> works just like a ReadHandle<T> (except that using it as a property directly is not supported). When the object is first accessed, the decoration is actually created (and a SG alias is made for the object under the C.d name). The handle also has functionality for accessing a decoration of type D, similarly to the interface provided by Decorator objects. You can either write the decoration from for SG::AuxElement object:

handle(o) = x;

or reference the element by its index in the container:

handle(i) = x;

Example:

class MyAlgorithm : public AthReentrantAlgorithm {
  ...
  SG::WriteDecorHandleKey<MyCont> m_key;
};
...
MyAlgorithm::MyAlgorithm (const std::string& name, ISvcLocator* svcloc)
  : AthReentrantAlgorithm (name, svcloc), ...
{
  declareProperty ("Key", m_key = "container.decor");
  ...
}
 
StatusCode MyAlgorithm::initialize()
{
  ATH_CHECK( m_key.initialize() );
  ...
}
 
StatusCode MyAlgorithm::execute (const EventContext& ctx) const
{
  SG::WriteDecorHandle<MyCont, float> h (m_key, ctx);
  for (const MyObj& o : *h) {  // Access the container.
    h (o) = calculate (o);  // Add the decoration.
    ...

When the decoration handle is destroyed, the decoration will be locked (i.e., converted to an ordinary variable).

Implementation note: we keep track of decorations using aliases. For a container C with decoration d, the WriteDecorHandle will make an alias C.d for C. The ReadDecorHandle will then retrieve C.d from StoreGate. The alias C.d is also what enters into scheduling decisions.

The key() method will return the key of the container. Use decorKey() to get the name used for the decoration alias.

Definition at line 98 of file StoreGate/StoreGate/WriteDecorHandle.h.

Member Typedef Documentation

◆ accessor_t

template<class T , class D >

using SG::WriteDecorHandle< T, D >::accessor_t = SG::AuxElement::Decorator<D>

Accessor type for aux data.

Definition at line 106 of file StoreGate/StoreGate/WriteDecorHandle.h.

◆ Base

template<class T , class D >

using SG::WriteDecorHandle< T, D >::Base = ReadHandle<T>

Base class.

Definition at line 103 of file StoreGate/StoreGate/WriteDecorHandle.h.

◆ container_pointer_type

template<class T , class D >

using SG::WriteDecorHandle< T, D >::container_pointer_type = typename accessor_t::container_pointer_type

Pointer into the vector holding an aux data item.

Definition at line 112 of file StoreGate/StoreGate/WriteDecorHandle.h.

◆ reference_type

template<class T , class D >

using SG::WriteDecorHandle< T, D >::reference_type = typename accessor_t::reference_type

Type referencing an aux data item.

Definition at line 109 of file StoreGate/StoreGate/WriteDecorHandle.h.

◆ span

template<class T , class D >

using SG::WriteDecorHandle< T, D >::span = typename accessor_t::span

Span of aux data items.

Definition at line 115 of file StoreGate/StoreGate/WriteDecorHandle.h.

Constructor & Destructor Documentation

◆ WriteDecorHandle() [1/4]

template<class T , class D >

SG::WriteDecorHandle< T, D >::WriteDecorHandle ( const WriteDecorHandleKey< T > & key )

explicit

Constructor from a WriteDecorHandleKey.

Parameters

key	The key object holding the clid/key/store/attr.

This will raise an exception if the StoreGate key is blank, or if the event store cannot be found.

◆ WriteDecorHandle() [2/4]

template<class T , class D >

SG::WriteDecorHandle< T, D >::WriteDecorHandle	(	const WriteDecorHandleKey< T > &	key,
		const EventContext &	ctx
	)

explicit

Constructor from a ReadDecorHandleKey and an explicit event context.

Parameters

key	The key object holding the clid/key.
ctx	The event context.

This will raise an exception if the StoreGate key is blank, or if the event store cannot be found.

If the default event store has been requested, then the thread-specific store from the event context will be used.

◆ WriteDecorHandle() [3/4]

template<class T , class D >

SG::WriteDecorHandle< T, D >::WriteDecorHandle ( const WriteDecorHandle< T, D > & rhs )

Copy constructor.

◆ WriteDecorHandle() [4/4]

template<class T , class D >

SG::WriteDecorHandle< T, D >::WriteDecorHandle ( WriteDecorHandle< T, D > && rhs )

Move constructor.

◆ ~WriteDecorHandle()

template<class T , class D >

SG::WriteDecorHandle< T, D >::~WriteDecorHandle ( )

Destructor.

This will lock the decoration.

Member Function Documentation

◆ auxid()

template<class T , class D >

SG::auxid_t SG::WriteDecorHandle< T, D >::auxid ( ) const

Return the aux id for this variable.

◆ decorKey()

template<class T , class D >

const std::string& SG::WriteDecorHandle< T, D >::decorKey ( ) const

Return the name of the decoration alias (CONT.DECOR).

◆ getDecorationArray()

template<class T , class D >

template<class POINTER_TYPE = container_pointer_type, typename = std::enable_if_t<!std::is_void_v<POINTER_TYPE> >>

POINTER_TYPE SG::WriteDecorHandle< T, D >::getDecorationArray ( )

Get a pointer to the start of the auxiliary data array, for the referenced object.

◆ getDecorationSpan()

template<class T , class D >

span SG::WriteDecorHandle< T, D >::getDecorationSpan ( )

Get a span over the auxilary data array, for the referenced object.

◆ isAvailable()

template<class T , class D >

bool SG::WriteDecorHandle< T, D >::isAvailable ( )

Test to see if this variable exists in the store, for the referenced object.

◆ isPresent()

template<class T , class D >

bool SG::WriteDecorHandle< T, D >::isPresent ( ) const

Is the referenced container present in SG?

Note that this tests for the presence of the container, not for the decoration.

Const method; the handle does not change as a result of this.

◆ makeDecor()

template<class T , class D >

void SG::WriteDecorHandle< T, D >::makeDecor ( const AuxVectorData * avd )

private

Create the decoration if it doesn't actually exist yet.

Also create the decoration alias in SG (unless this handle has been renounced).

Parameters

avd	The AuxVectorData instance we're decorating. (May not be the same as this->vectorData() if the handle has been renounced.)

◆ mode()

template<class T , class D >

Gaudi::DataHandle::Mode SG::WriteDecorHandle< T, D >::mode ( ) const

Return the mode (read/write/update) for this handle.

◆ operator()() [1/2]

template<class T , class D >

reference_type SG::WriteDecorHandle< T, D >::operator() ( const AuxElement & e )

Fetch the variable for one element, as a reference.

Parameters

e	The element for which to fetch the variable.

◆ operator()() [2/2]

template<class T , class D >

reference_type SG::WriteDecorHandle< T, D >::operator() ( size_t index )

Fetch the variable for one element, as a reference.

Parameters

index The index of the desired element.

This looks up the variable in the object referenced by this handle. For a standalone object, pass an index of 0.

◆ operator=() [1/2]

template<class T , class D >

WriteDecorHandle& SG::WriteDecorHandle< T, D >::operator= ( const WriteDecorHandle< T, D > & rhs )

Assignment operator.

◆ operator=() [2/2]

template<class T , class D >

WriteDecorHandle& SG::WriteDecorHandle< T, D >::operator= ( WriteDecorHandle< T, D > && rhs )

Move operator.

◆ setProxyDict()

template<class T , class D >

virtual StatusCode SG::WriteDecorHandle< T, D >::setProxyDict ( IProxyDict * store )

overridevirtual

Explicitly set the event store.

Parameters

store The new event store.

This implicitly does a reset().

We need to override this so that the setting gets made on the container handle as well.

◆ vectorData() [1/3]

template<class T , class D >

const SG::AuxVectorData* SG::WriteDecorHandle< T, D >::vectorData ( )

private

Return the referenced object as a SG::AuxVectorData.

If T is a container object, then this should be the object itself. But if it is a standalone object, deriving from SG::AuxElement, then we need to call container() on the object.

◆ vectorData() [2/3]

template<class T , class D >

const SG::AuxVectorData* SG::WriteDecorHandle< T, D >::vectorData ( std::false_type )

private

Return the referenced object as a SG::AuxVectorData.

Specialization for the case of a container (T does not derive from SG::AuxElement).

◆ vectorData() [3/3]

template<class T , class D >

const SG::AuxVectorData* SG::WriteDecorHandle< T, D >::vectorData ( std::true_type )

private

Return the referenced object as a SG::AuxVectorData.

Specialization for the case of a standalone object (T derives from SG::AuxElement).

Member Data Documentation

◆ m_acc

template<class T , class D >

accessor_t SG::WriteDecorHandle< T, D >::m_acc

private

Accessor for the aux data item.

Definition at line 297 of file StoreGate/StoreGate/WriteDecorHandle.h.

◆ m_decorated

template<class T , class D >

bool SG::WriteDecorHandle< T, D >::m_decorated

private

Have we created the decoration?

Definition at line 303 of file StoreGate/StoreGate/WriteDecorHandle.h.

◆ m_decorKey

template<class T , class D >

std::string SG::WriteDecorHandle< T, D >::m_decorKey

private

Name of the decoration alias: CONT.DECOR.

Definition at line 294 of file StoreGate/StoreGate/WriteDecorHandle.h.

◆ m_renounced

template<class T , class D >

bool SG::WriteDecorHandle< T, D >::m_renounced

private

Was this handle renounced?

Definition at line 300 of file StoreGate/StoreGate/WriteDecorHandle.h.

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

StoreGate/StoreGate/WriteDecorHandle.h

Public Types

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

template<class T, class D> class SG::WriteDecorHandle< T, D >

Member Typedef Documentation

◆ accessor_t

◆ Base

◆ container_pointer_type

◆ reference_type

◆ span

Constructor & Destructor Documentation

◆ WriteDecorHandle() [1/4]

◆ WriteDecorHandle() [2/4]

◆ WriteDecorHandle() [3/4]

◆ WriteDecorHandle() [4/4]

◆ ~WriteDecorHandle()

Member Function Documentation

◆ auxid()

◆ decorKey()

◆ getDecorationArray()

◆ getDecorationSpan()

◆ isAvailable()

◆ isPresent()

◆ makeDecor()

◆ mode()

◆ operator()() [1/2]

◆ operator()() [2/2]

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ setProxyDict()

◆ vectorData() [1/3]

◆ vectorData() [2/3]

◆ vectorData() [3/3]

Member Data Documentation

◆ m_acc

◆ m_decorated

◆ m_decorKey

◆ m_renounced

template<class T, class D>
class SG::WriteDecorHandle< T, D >