asg::SgTEventMeta Class Reference

Wrapper class providing StoreGate-like access to metadata in ROOT. More...

#include <SgTEventMeta.h>

Collaboration diagram for asg::SgTEventMeta:

Public Types
enum	StoreType { InputStore = 0, OutputStore = 1 }
	Type of the store that this object implements. More...

Public Member Functions
	SgTEventMeta (StoreType type, xAOD::TEvent *event=0)
	Constructor with a type and an optional TEvent pointer. More...
	SgTEventMeta (SgTEventMeta &&other) noexcept
	Move constructor. More...
SgTEventMeta &	operator= (SgTEventMeta &&other) noexcept
	Move assignment operator. More...
SgTEventMeta &	operator= (xAOD::TEvent *event)
	Assignment operator to handle direct event pointer assignment. More...
	SgTEventMeta (const SgTEventMeta &)=delete
SgTEventMeta &	operator= (const SgTEventMeta &)=delete
Functions providing access to the metadata payload
template<typename T >
bool	contains (const std::string &name)
	Check if an object is available for constant access. More...
template<typename T >
bool	transientContains (const std::string &name) const
	Check if an object is available for non-constant access. More...
template<typename T >
StatusCode	retrieve (T *&obj, const std::string &name)
	Retrieve a non-constant pointer to an object in the store. More...
template<typename T >
StatusCode	retrieve (const T *&obj, const std::string &name)
	Retrieve a constant pointer to an object in the store. More...
template<typename T >
StatusCode	record (std::unique_ptr< T > obj, const std::string &cname)
	Record an object/container using a smart pointer for ownership. More...
template<typename T >
StatusCode	record (T *obj, const std::string &name)
	Record an object into the store. More...
template<typename T >
void	keys (std::vector< std::string > &vkeys) const
	provide list of all keys associated with a type. More...

Private Member Functions
StatusCode	initialize () const
	Function initialising the object. More...

Private Attributes
StoreType	m_type
	Type of this store. More...
std::atomic< xAOD::TEvent * >	m_event
	Pointer to the xAOD::TEvent object in use. More...

Detailed Description

Wrapper class providing StoreGate-like access to metadata in ROOT.

In Athena we access the input and output metadata stores with two separate StoreGateSvc instances. In ROOT the access to the metadata content of the input/output files is provided using the same xAOD::TEvent object that we use to access the event content of these files as well. To emulate the same pattern for the dual-use tools that Athena provides, this wrapper is used.

It behaves pretty much like SgTEvent, but I didn't want to make that class even more complicated. Instead decided to implement the metadata access using this independent class.

Author

Attila Krasznahorkay Attil.nosp@m.a.Kr.nosp@m.aszna.nosp@m.hork.nosp@m.ay@ce.nosp@m.rn.c.nosp@m.h

Revision

611829

Date

2014-08-14 15:53:41 +0200 (Thu, 14 Aug 2014)

Definition at line 45 of file SgTEventMeta.h.

Member Enumeration Documentation

StoreType

enum asg::SgTEventMeta::StoreType

Type of the store that this object implements.

Enumerator
InputStore	This store is used to access the input metadata.
OutputStore	This store is used to access the output metadata.

Definition at line 49 of file SgTEventMeta.h.

                     {
         InputStore  = 0, 
         OutputStore = 1  
      }; // enum StoreType

Constructor & Destructor Documentation

SgTEventMeta() [1/3]

asg::SgTEventMeta::SgTEventMeta	(	StoreType	type,
		xAOD::TEvent *	event = 0
	)

Constructor with a type and an optional TEvent pointer.

Definition at line 16 of file SgTEventMeta.cxx.

      : m_type( type ) {
      m_event.store(event);
   }

SgTEventMeta() [2/3]

asg::SgTEventMeta::SgTEventMeta ( SgTEventMeta &&  other )

noexcept

Move constructor.

Definition at line 21 of file SgTEventMeta.cxx.

      : m_type(other.m_type) {
      m_event.store(other.m_event.load());
   }

SgTEventMeta() [3/3]

asg::SgTEventMeta::SgTEventMeta ( const SgTEventMeta &  )

delete

Member Function Documentation

contains()

template<typename T >

bool asg::SgTEventMeta::contains

(

const std::string &

name

)

Check if an object is available for constant access.

initialize()

StatusCode asg::SgTEventMeta::initialize ( ) const

private

Function initialising the object.

This function is used by the template functions to try to retrieve a valid pointer to the active TEvent object, if one is not available yet.

Returns

StatusCode::FAILURE if TEvent can't be found, StatusCode::SUCCESS otherwise

Definition at line 46 of file SgTEventMeta.cxx.

                                             {
 
      // Return right away if we already have a non-null pointer:
      if (m_event && m_event.load()) {
         return StatusCode::SUCCESS;
      }
 
      // Check if there's an active event:
      xAOD::TVirtualEvent* event = xAOD::TActiveEvent::event();
      if( ! event ) {
         std::cout << META_ERROR_SOURCE << "Couldn't find an active event in "
                   << "the job" << std::endl;
         return StatusCode::FAILURE;
      }
 
      // This should actually be a TEvent:
      m_event.store(dynamic_cast< xAOD::TEvent* >( event ));
      if( !m_event || !m_event.load() ) {
         std::cout << META_ERROR_SOURCE << "The active event is not of type "
                   << "xAOD::TEvent?!?" << std::endl;
         return StatusCode::FAILURE;
      }
 
      // We succeeded:
      return StatusCode::SUCCESS;
   }

keys()

template<typename T >

void asg::SgTEventMeta::keys

(

std::vector< std::string > &

vkeys

)

const

provide list of all keys associated with a type.

usage: store->keys< type >(vector_to_fill)

Parameters

vkeys

will be filled with list of keys (may be empty)

operator=() [1/3]

SgTEventMeta& asg::SgTEventMeta::operator= ( const SgTEventMeta &  )

delete

operator=() [2/3]

SgTEventMeta & asg::SgTEventMeta::operator= ( SgTEventMeta &&  other )

noexcept

Move assignment operator.

Definition at line 26 of file SgTEventMeta.cxx.

                                                                      {
      if (this != &other) {
         m_type = other.m_type;
         m_event.store(other.m_event.load());
      }
      return *this;
   }

operator=() [3/3]

SgTEventMeta & asg::SgTEventMeta::operator=

(

xAOD::TEvent *

event

)

Assignment operator to handle direct event pointer assignment.

Definition at line 34 of file SgTEventMeta.cxx.

                                                          {
      m_event.store(event);
      return *this;
   }

record() [1/2]

template<typename T >

StatusCode asg::SgTEventMeta::record	(	std::unique_ptr< T >	obj,
		const std::string &	cname
	)

Record an object/container using a smart pointer for ownership.

record() [2/2]

template<typename T >

StatusCode asg::SgTEventMeta::record	(	T *	obj,
		const std::string &	name
	)

Record an object into the store.

retrieve() [1/2]

template<typename T >

StatusCode asg::SgTEventMeta::retrieve	(	const T *&	obj,
		const std::string &	name
	)

Retrieve a constant pointer to an object in the store.

retrieve() [2/2]

template<typename T >

StatusCode asg::SgTEventMeta::retrieve	(	T *&	obj,
		const std::string &	name
	)

Retrieve a non-constant pointer to an object in the store.

transientContains()

template<typename T >

bool asg::SgTEventMeta::transientContains

(

const std::string &

name

)

const

Check if an object is available for non-constant access.

Member Data Documentation

m_event

std::atomic<xAOD::TEvent*> asg::SgTEventMeta::m_event

mutableprivate

Pointer to the xAOD::TEvent object in use.

Definition at line 110 of file SgTEventMeta.h.

m_type

StoreType asg::SgTEventMeta::m_type

private

Type of this store.

Definition at line 108 of file SgTEventMeta.h.

---

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

• SgTEventMeta.h
• SgTEventMeta.cxx