util::LocalArtHandleTrackerManager< Event > Class Template Reference

Variant of util::ArtHandleTrackerManager in local scope. More...

#include <ArtHandleTrackerManager.h>

Public Types
using	Event_t = typename ArtHandleTrackerManager< Event >::Event_t
	Type of the art event. More...

Public Member Functions
	LocalArtHandleTrackerManager (Event const &event, bool removeCache=true)
	Constructor: operates on the specified event. More...
	~LocalArtHandleTrackerManager ()
	Destructor; will implement the RAII pattern (i.e. call doneWithEvent()). More...
template<typename Handle >
auto	registerHandle (Handle &&handle) -> decltype(auto)
Queries
unsigned int	nTrackedHandles () const
	Returns the number of handles currently tracked. More...
bool	willRemoveCachedProducts () const
Registration of data products
template<typename T , typename... Args>
art::Handle< T >	getHandle (Args &&...args)
	Retrieves an handle from the event, and registers it. More...
template<typename T , typename... Args>
art::ValidHandle< T >	getValidHandle (Args &&...args)
	Retrieves a valid handle from the event, and registers it. More...
template<typename Handle >
decltype(auto)	registerHandle (Handle &&handle)
	Registers an existing handle. More...
Operations
void	setRemoveCachedProducts (bool removeCache)
	Sets whether to remove tracked data caches on destruction or not. More...
unsigned int	removeCachedProducts ()
	Clears the cached data products for all tracked handles. More...
void	forgetAllHandles ()
	Stops tracking any handle, without removing their cache first. More...
unsigned int	doneWithEvent (bool removeCache)
	Completes the work on the associated event. More...
unsigned int	doneWithEvent ()
	Completes the work on the associated event. More...

Private Attributes
ArtHandleTrackerManager< Event >	fManager
	The actual manager doing the work. More...
bool	fRemoveCache
	Whether to remove cache on destructor. More...

Detailed Description

template<typename Event>
class util::LocalArtHandleTrackerManager< Event >

Variant of util::ArtHandleTrackerManager in local scope.

Template Parameters

Event

the type of data product source (the "principal") to serve

This class allows the removal of data products cached in an event. The general functionality is described in util::ArtHandleTrackerManager.

This class in particular offers a tuned interface for the case where the object is local (which is convenient for multithreading and if all the reading and usage happens in the same scope):

• the object supports being associated to only one event in its lifetime, and the association must be established on construction;
• removal is automatically performed on destruction at the exit of the scope of the object (this is "Resource Acquisition Is Initialization" idiom)

Whether the object will actually remove the caches can be decided on construction (by default it does), and then changed with setRemoveCachedProducts(). The removal can also be anticipated by explicitly calling doneWithEvent() (no event parameter is supported), after which the destruction will not do anything.

Example:

void MyModule::analyze(art::Event const & event) override {

  util::LocalArtHandleTrackerManager dataCacheRemover{ event };

  auto const& handle = dataCacheRemover.getHandle<MyDataProduct>(fTag);

  auto results = processData(*handle); // ... or whatever

  results.Write(); // ... or another portion of whatever
}

Definition at line 33 of file ArtHandleTrackerManager.h.

Member Typedef Documentation

template<typename Event >

using util::LocalArtHandleTrackerManager< Event >::Event_t = typename ArtHandleTrackerManager<Event>::Event_t

Type of the art event.

Definition at line 429 of file ArtHandleTrackerManager.h.

Constructor & Destructor Documentation

template<typename Event >

util::LocalArtHandleTrackerManager< Event >::LocalArtHandleTrackerManager	(	Event const &	event,
		bool	removeCache = true
	)

Constructor: operates on the specified event.

Parameters

event	the event this object will operate on
removeCache	(default: true) remove tracked data caches when done

The parameter removeCache controls whether the data caches are removed on destruction. It may be changed along the way with setRemoveCachedProducts().

Definition at line 997 of file ArtHandleTrackerManager.h.

  : fManager{ event }, fRemoveCache{ removeCache }
  {}

template<typename Event >

util::LocalArtHandleTrackerManager< Event >::~LocalArtHandleTrackerManager

(

)

Destructor; will implement the RAII pattern (i.e. call doneWithEvent()).

Definition at line 1004 of file ArtHandleTrackerManager.h.

  { doneWithEvent(); }

Member Function Documentation

template<typename Event >

unsigned int util::LocalArtHandleTrackerManager< Event >::doneWithEvent

(

bool

removeCache

)

Completes the work on the associated event.

Parameters

removeCache

(default: true) removes tracked data product caches

Returns

the number of cleared data product caches

See Also

doneWithEvent()

This is a shortcut for having optional release of cache in a single call, depending on the value of removeCache:

• if true, removeCachedProducts() is called and its count is returned;
• if false, forgetAllHandles() is called and 0 is returned.

Differently from util::ArtHandleTrackerManager, the object is not disassociated from the event: new handles can be registered and the clearing settings are preserved as they are. To be really done with the event, setRemoveCachedProducts() needs to be set to false, and users should refrain from calling `removeCachedProducts().

This method ignores and overrides the value set by setRemoveCachedProducts() and the one at construction.

Definition at line 1068 of file ArtHandleTrackerManager.h.

{
  assert(fManager.hasEvent());
  
  if (removeCache) return removeCachedProducts();
  
  forgetAllHandles();
  return 0;
} // util::LocalArtHandleTrackerManager<Event>::doneWithEvent()

template<typename Event >

unsigned int util::LocalArtHandleTrackerManager< Event >::doneWithEvent

(

)

Completes the work on the associated event.

Returns

the number of cleared data product caches

See Also

doneWithEvent(bool), setRemoveCachedProducts()

This is a shortcut for having optional release of cache in a single call, depending on the value of willRemoveCachedProducts():

• if true, removeCachedProducts() is called and its count is returned;
• if false, forgetAllHandles() is called and 0 is returned.

In addition, the object is disassociated from the event, and the object will not be available for use any more.

Definition at line 1081 of file ArtHandleTrackerManager.h.

  { return doneWithEvent(willRemoveCachedProducts()); }

template<typename Event >

void util::LocalArtHandleTrackerManager< Event >::forgetAllHandles

(

)

Stops tracking any handle, without removing their cache first.

Definition at line 1061 of file ArtHandleTrackerManager.h.

  { return fManager.forgetAllHandles(); }

template<typename Event >

template<typename T , typename... Args>

art::Handle< T > util::LocalArtHandleTrackerManager< Event >::getHandle

(

Args &&...

args

)

Retrieves an handle from the event, and registers it.

Template Parameters

T	type of data product to retrieve
Args	types of the arguments needed by art::getHandle()

Parameters

args	all the arguments that art::getHandle() requires

Returns

the handle just read and being managed

See Also

getValidHandle(), registerHandle()

This function wraps art::Event::getHandle(), calling it to obtain the handle and then registering it (like with registerHandle()).

Definition at line 1024 of file ArtHandleTrackerManager.h.

  { return fManager.template getHandle<T>(std::forward<Args>(args)...); }

template<typename Event >

template<typename T , typename... Args>

art::ValidHandle< T > util::LocalArtHandleTrackerManager< Event >::getValidHandle

(

Args &&...

args

)

Retrieves a valid handle from the event, and registers it.

Template Parameters

T	type of data product to retrieve
Args	types of the arguments needed by art::getValidHandle()

Parameters

args	all the arguments that art::getValidHandle() requires

Returns

the handle just read and being managed

See Also

getHandle(), registerHandle()

This is the art::ValidHandle sibling of getHandle(). See that one for details.

Definition at line 1032 of file ArtHandleTrackerManager.h.

  { return fManager.template getValidHandle<T>(std::forward<Args>(args)...); }

template<typename Event >

unsigned int util::LocalArtHandleTrackerManager< Event >::nTrackedHandles

(

)

const

Returns the number of handles currently tracked.

Definition at line 1010 of file ArtHandleTrackerManager.h.

  {return fManager.nTrackedHandles(); }

template<typename Event >

template<typename Handle >

decltype(auto) util::LocalArtHandleTrackerManager< Event >::registerHandle

(

Handle &&

handle

)

Registers an existing handle.

Template Parameters

Handle

the type of handle to register

Parameters

handle

the handle to be registered

Returns

the same handle is passed through

This method registers a copy of handle into the manager.

template<typename Event >

template<typename Handle >

auto util::LocalArtHandleTrackerManager< Event >::registerHandle

(

Handle &&

handle

)

-> decltype(auto)

Definition at line 1040 of file ArtHandleTrackerManager.h.

{
  return fManager.template registerHandle<Handle>(std::forward<Handle>(handle)); 
}

template<typename Event >

unsigned int util::LocalArtHandleTrackerManager< Event >::removeCachedProducts

(

)

Clears the cached data products for all tracked handles.

Returns

the number of tracked handles which had their cache removed

This method calls Event_t::removeCachedProduct() for all tracked handles. This is the core functionality of the manager, which removes the cache of all tracked handles.

The art framework always makes the handles used to remove the cache invalid (Handle::clear()). After the removal, the object stops tracking the handles (like with a call to forgetAllHandles()).

Calling this method when there are no handles registered has no effect.

Definition at line 1055 of file ArtHandleTrackerManager.h.

  { return fManager.removeCachedProducts(); }

template<typename Event >

void util::LocalArtHandleTrackerManager< Event >::setRemoveCachedProducts

(

bool

removeCache

)

Sets whether to remove tracked data caches on destruction or not.

Parameters

removeCache

if true, data caches will be removed on destruction

Definition at line 1049 of file ArtHandleTrackerManager.h.

  { fRemoveCache = removeCache; }

template<typename Event >

bool util::LocalArtHandleTrackerManager< Event >::willRemoveCachedProducts

(

)

const

Returns whether caches will be removed on destruction.

See Also

setRemoveCachedProducts()

Definition at line 1016 of file ArtHandleTrackerManager.h.

  { return fRemoveCache; }

Member Data Documentation

template<typename Event >

ArtHandleTrackerManager<Event> util::LocalArtHandleTrackerManager< Event >::fManager

private

The actual manager doing the work.

Definition at line 422 of file ArtHandleTrackerManager.h.

template<typename Event >

bool util::LocalArtHandleTrackerManager< Event >::fRemoveCache

private

Whether to remove cache on destructor.

Definition at line 424 of file ArtHandleTrackerManager.h.

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

• ArtHandleTrackerManager.h