Handle for requesting thinning for a data object. More...

#include <ThinningHandle.h>

Inheritance diagram for SG::ThinningHandle< T >:

Collaboration diagram for SG::ThinningHandle< T >:

Public Types
using	Op = ThinningDecision::Op

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

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

void	thin (size_t ndx)
	Mark that index `ndx` in the container should be thinned away. More...

void	thin (const std::vector< bool > &v, Op op=Op::Set)
	Set the thinning state for the container from a bitmask. More...

void	thin (const ThinningDecisionBase &other, Op op=Op::Set)
	Set the thinning state for the container from a bitmask. More...

void	keep (size_t ndx)
	Mark that index `ndx` in the container should be kept (not thinned away). More...

void	keep (const std::vector< bool > &v, Op op=Op::Set)
	Set the thinning state for the container from a bitmask. More...

void	keep (const ThinningDecisionBase &other, Op op=Op::Set)
	Set the thinning state for the container from a bitmask. More...

void	thinAll ()
	Mark that all elements should be thinned away. More...

void	keepAll ()
	Mark that all elements should be kept (not thinned). More...

const ThinningDecision &	decision () const
	Return the thinning object we're building. More...

Private Attributes
WriteHandle< ThinningDecision >	m_decisionHandle
	Handle for writing the decision object. More...

std::unique_ptr< ThinningDecision >	m_decision
	The thinning object we're building. More...

Detailed Description

template<class T>
class SG::ThinningHandle< T >

Handle for requesting thinning for a data object.

A ThinningHandle + ThinningHandleKey is used to request thinning for a data object for a particular stream.

To use it, you should first create a ThinningHandleKey referencing the object you want to thin, in the same way as for a ReadHandle:

SG::ThinningHandleKey<MyObjectContainer> m_objkey

{ this, "ObjKey", "obj", "Object to be thinned." };

When you initialize the key, you should pass it the the name of the stream for which thinning is being done:

StringProperty m_stream{ this, "Stream", "OutStream", "Stream name for thinning" };
...
ATH_CHECK( m_objkey.initialize (m_streamName);

Then you can create a ThinningHandle from the key in the way in which you would create a ReadHandle:

SG::ThinningHandle<MyObjectContainer> h (m_objkey, ctx);

This handle can then be used to access the object in the same way in which you would use a ReadHandle. In addition, you can call methods on the handle to specify objects to thin:

size_t iobj = 0;
for (const MyObject* obj : *h) {
  if (obj->pt() < m_thresh) {
    h.thin (iobj);
  }
  ++iobj;
}

See ThinningHandleBase for a full list of the methods that may be used to specify the thinning.

The thinning request will be committed when the ThinningHandle is destroyed.

If the same object is thinned for the same stream in multiple algorithms, then the result will be the AND of all of them; that is, an element will be thinned on the output only if it has been requested to be thinned by all algorithms.

For a complete example, see DataModelTestDataCommon/xAODTestThinCVec.

Definition at line 82 of file ThinningHandle.h.

Member Typedef Documentation

◆ Op

template<class T >

using SG::ThinningHandle< T >::Op = ThinningDecision::Op

Definition at line 86 of file ThinningHandle.h.

Constructor & Destructor Documentation

◆ ThinningHandle() [1/2]

template<class T >

SG::ThinningHandle< T >::ThinningHandle ( const ThinningHandleKey< T > & key )

inlineexplicit

Constructor from a ThinningHandleKey.

Parameters

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

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

Definition at line 96 of file ThinningHandle.h.

     : ThinningHandle (key, Gaudi::Hive::currentContext())
   {
   }

◆ ThinningHandle() [2/2]

template<class T >

SG::ThinningHandle< T >::ThinningHandle	(	const ThinningHandleKey< T > &	key,
		const EventContext &	ctx
	)

inlineexplicit

Constructor from a ThinningHandleKey and an explicit event context.

Parameters

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

Definition at line 113 of file ThinningHandle.h.

     : ReadHandle<T> (key, ctx),
       ThinningHandleBase (key.decisionHandleKey(), key.key(), ctx)
   {
   }

Member Function Documentation

◆ decision()

const ThinningDecision & SG::ThinningHandleBase::decision ( ) const

inherited

Return the thinning object we're building.

Definition at line 154 of file ThinningHandleBase.cxx.

 {
   return *m_decision;
 }

◆ keep() [1/3]

void SG::ThinningHandleBase::keep	(	const std::vector< bool > &	v,
		Op	op = `Op::Set`
	)

inherited

Set the thinning state for the container from a bitmask.

Parameters

v	Thinning state mask; should have the same size as the container. Element `ndx` should be kept if bit `ndx` is set in the map.
op	Logical operation for combining with existing thinning state. Set — Keep if `flag` is true (overwriting anything originally set for this element). And — Keep if `flag` is true and element was originally kept, else not. Or — Keep if `flag` is true or element was originally kept, else not.

Definition at line 98 of file ThinningHandleBase.cxx.

 {
   m_decision->keep (v, op);
 }

◆ keep() [2/3]

void SG::ThinningHandleBase::keep	(	const ThinningDecisionBase &	other,
		Op	op = `Op::Set`
	)

inherited

Set the thinning state for the container from a bitmask.

Parameters

other	Thinning state mask; should have the same size as the container. Element `ndx` should be kept if bit `ndx` is set in the map.
op	Logical operation for combining with existing thinning state. Set — Keep if `flag` is true (overwriting anything originally set for this element). And — Keep if `flag` is true and element was originally kept, else not. Or — Keep if `flag` is true or element was originally kept, else not.

Definition at line 127 of file ThinningHandleBase.cxx.

 {
   m_decision->keep (other, op);
 }

◆ keep() [3/3]

void SG::ThinningHandleBase::keep ( size_t ndx )

inherited

Mark that index ndx in the container should be kept (not thinned away).

Parameters

ndx	Index of element to keep.

Definition at line 68 of file ThinningHandleBase.cxx.

 {
   m_decision->keep (ndx);
 }

◆ keepAll()

void SG::ThinningHandleBase::keepAll ( )

inherited

Mark that all elements should be kept (not thinned).

Definition at line 145 of file ThinningHandleBase.cxx.

 {
   return m_decision->keepAll();
 }

◆ thin() [1/3]

void SG::ThinningHandleBase::thin	(	const std::vector< bool > &	v,
		Op	op = `Op::Set`
	)

inherited

Set the thinning state for the container from a bitmask.

Parameters

v	Thinning state mask; should have the same size as the container. Element `ndx` should be thinned if bit `ndx` is set in the map.
op	Logical operation for combining with existing thinning state. Set — Thin if `flag` is true (overwriting anything originally set for this element). And — Thin if `flag` is true and element was originally thinned, else not. Or — Thin if `flag` is true or element was originally thinned, else not.

Definition at line 83 of file ThinningHandleBase.cxx.

 {
   m_decision->thin (v, op);
 }

◆ thin() [2/3]

void SG::ThinningHandleBase::thin	(	const ThinningDecisionBase &	other,
		Op	op = `Op::Set`
	)

inherited

Set the thinning state for the container from a bitmask.

Parameters

other	Thinning state mask; should have the same size as the container. Element `ndx` should be thinned if bit `ndx` is set in the map.
op	Logical operation for combining with existing thinning state. Set — Thin if `flag` is true (overwriting anything originally set for this element). And — Thin if `flag` is true and element was originally thinned, else not. Or — Thin if `flag` is true or element was originally thinned, else not.

Definition at line 112 of file ThinningHandleBase.cxx.

 {
   m_decision->thin (other, op);
 }

◆ thin() [3/3]

void SG::ThinningHandleBase::thin ( size_t ndx )

inherited

Mark that index ndx in the container should be thinned away.

Parameters

ndx	Index of element to thin.

Definition at line 57 of file ThinningHandleBase.cxx.

 {
   m_decision->thin (ndx);
 }

◆ thinAll()

void SG::ThinningHandleBase::thinAll ( )

inherited

Mark that all elements should be thinned away.

Definition at line 136 of file ThinningHandleBase.cxx.

 {
   return m_decision->thinAll();
 }

Member Data Documentation

◆ m_decision

std::unique_ptr<ThinningDecision> SG::ThinningHandleBase::m_decision

privateinherited

The thinning object we're building.

Definition at line 141 of file ThinningHandleBase.h.

◆ m_decisionHandle

WriteHandle<ThinningDecision> SG::ThinningHandleBase::m_decisionHandle

privateinherited

Handle for writing the decision object.

Definition at line 138 of file ThinningHandleBase.h.

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

ThinningHandle.h

Public Types

Public Member Functions

Private Attributes

Detailed Description

template<class T> class SG::ThinningHandle< T >

Member Typedef Documentation

◆ Op

Constructor & Destructor Documentation

◆ ThinningHandle() [1/2]

◆ ThinningHandle() [2/2]

Member Function Documentation

◆ decision()

◆ keep() [1/3]

◆ keep() [2/3]

◆ keep() [3/3]

◆ keepAll()

◆ thin() [1/3]

◆ thin() [2/3]

◆ thin() [3/3]

◆ thinAll()

Member Data Documentation

◆ m_decision

◆ m_decisionHandle

template<class T>
class SG::ThinningHandle< T >