ROOT::Experimental::TDirectory Class Reference

Key/value store of objects.

Given a name, a TDirectory can store and retrieve an object. It will manage shared ownership through a shared_ptr.

Example: TDirectory dirMC; TDirectory dirHiggs;

dirMC.Add("higgs", histHiggsMC); dirHiggs.Add("mc", histHiggsMC);

Definition at line 70 of file TDirectory.hxx.

Classes
struct	ToContentType

Public Types
enum	EFindStatus { EFindStatus::kValidValue, EFindStatus::kValidValueBase, EFindStatus::kKeyNameNotFound, EFindStatus::kTypeMismatch }
	Status of the call to Find<T>(name). More...

Public Member Functions
template<class T >
void	Add (std::string_view name, const std::shared_ptr< T > &ptr)
	Add an existing object (rather a shared_ptr to it) to the TDirectory. More...
template<class T , class... ARGS>
std::shared_ptr< ToContentType_t< T > >	Create (std::string_view name, ARGS &&... args)
	Create an object of type T (passing some arguments to its constructor). More...
Internal::TDirectoryEntry	Find (std::string_view name) const
	Find the TDirectoryEntry associated to the name. More...
template<class T >
std::pair< Internal::TDirectoryEntry, EFindStatus >	Find (std::string_view name) const
	Find the TDirectoryEntry associated with the name. More...
template<class T >
std::shared_ptr< ToContentType_t< T > >	Get (std::string_view name)
	Get the object for a key. More...

Static Public Member Functions
static TDirectory &	Heap ()
	Dedicated, process-wide TDirectory. More...

Private Types
using	ContentMap_t = std::unordered_map< std::string, Internal::TDirectoryEntry >
	The directory content is a hashed map of name => Internal::TDirectoryEntry. More...
template<class T >
using	ToContentType_t = typename ToContentType< T >::type

Private Attributes
ContentMap_t	fContent
	The TDirectory's content. More...

#include <ROOT/TDirectory.hxx>

Inheritance diagram for ROOT::Experimental::TDirectory:

Member Typedef Documentation

ContentMap_t

using ROOT::Experimental::TDirectory::ContentMap_t = std::unordered_map<std::string, Internal::TDirectoryEntry>

private

The directory content is a hashed map of name => Internal::TDirectoryEntry.

Definition at line 75 of file TDirectory.hxx.

ToContentType_t

template<class T >

using ROOT::Experimental::TDirectory::ToContentType_t = typename ToContentType<T>::type

private

Definition at line 89 of file TDirectory.hxx.

Member Enumeration Documentation

EFindStatus

enum ROOT::Experimental::TDirectory::EFindStatus

strong

Status of the call to Find<T>(name).

Enumerator
kValidValue	Value known for this key name and type.
kValidValueBase	Value known for this key name and base type.
kKeyNameNotFound	No key is known for this name.
kTypeMismatch	The provided type does not match the value's type.

Definition at line 118 of file TDirectory.hxx.

Member Function Documentation

Add()

template<class T >

void ROOT::Experimental::TDirectory::Add ( std::string_view  name, const std::shared_ptr< T > &  ptr  )

inline

Add an existing object (rather a shared_ptr to it) to the TDirectory.

The TDirectory will have shared ownership.

Definition at line 172 of file TDirectory.hxx.

Create()

template<class T , class... ARGS>

std::shared_ptr<ToContentType_t<T> > ROOT::Experimental::TDirectory::Create ( std::string_view  name, ARGS &&...  args  )

inline

Create an object of type T (passing some arguments to its constructor).

The TDirectory will have shared ownership of the object.

Parameters

name	- Key of the object.
args	- arguments to be passed to the constructor of T

Definition at line 98 of file TDirectory.hxx.

Find() [1/2]

Internal::TDirectoryEntry ROOT::Experimental::TDirectory::Find ( std::string_view  name ) const

inline

Find the TDirectoryEntry associated to the name.

Returns empty TDirectoryEntry if nothing is found.

Definition at line 107 of file TDirectory.hxx.

Find() [2/2]

template<class T >

std::pair<Internal::TDirectoryEntry, EFindStatus> ROOT::Experimental::TDirectory::Find ( std::string_view  name ) const

inline

Find the TDirectoryEntry associated with the name.

Returns

empty TDirectoryEntry in first if nothing is found, or if the type does not match the expected type. second contains the reason.

Note

if second is kValidValue, then static_pointer_cast<T>(first.GetPointer()) is shared_ptr<T> to initially stored object

if second is kValidValueBase, then first.CastPointer<T>() is a valid cast to base class T of the stored object

Definition at line 133 of file TDirectory.hxx.

Get()

template<class T >

std::shared_ptr<ToContentType_t<T> > ROOT::Experimental::TDirectory::Get ( std::string_view  name )

inline

Get the object for a key.

T can be the object's type or a base class. The TDirectory will return the same object for subsequent calls to Get().

Returns

a shared_ptr to the object or its base.

Exceptions

TDirectoryUnknownKey	if no object is stored under this name.
TDirectoryTypeMismatch	if the object stored under this name is of a type that is not a derived type of T.

Definition at line 153 of file TDirectory.hxx.

Heap()

ROOT::Experimental::TDirectory & TDirectory::Heap ( )

static

Dedicated, process-wide TDirectory.

Note

This is not thread-safe. You will need to syncronize yourself. In general it's a bad idea to use a global collection in a multi-threaded environment; ROOT itself does not make use of it. It is merely offered for historical, process-wide object registration by name. Instead, pass a pointer to the object where you need to access it - this is also much faster than a lookup by name.

Definition at line 23 of file TFile.cxx.

Member Data Documentation

fContent

ContentMap_t ROOT::Experimental::TDirectory::fContent

private

The TDirectory's content.

Definition at line 78 of file TDirectory.hxx.

Libraries for ROOT::Experimental::TDirectory:

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