The RNTupleModel encapulates the schema of an ntuple.

The ntuple model comprises a collection of hierarchically organized fields. From a model, "entries" can be extracted. For convenience, the model provides a default entry. Models have a unique model identifier that faciliates checking whether entries are compatible with it (i.e.: have been extracted from that model).

Definition at line 45 of file RNTupleModel.hxx.

Public Member Functions
	RNTupleModel ()

	RNTupleModel (const RNTupleModel &)=delete

	~RNTupleModel ()=default

template<typename T >
void	AddField (std::pair< std::string_view, std::string_view > fieldNameDesc, T *fromWhere)
	Throws an exception if fromWhere is null.

template<typename T >
void	AddField (std::string_view fieldName, T *fromWhere)
	Throws an exception if fromWhere is null.

void	AddField (std::unique_ptr< Detail::RFieldBase > field)
	Adds a field whose type is not known at compile time.

std::unique_ptr< RNTupleModel >	Clone () const

std::unique_ptr< REntry >	CreateEntry ()

template<typename T >
T *	Get (std::string_view fieldName)

REntry *	GetDefaultEntry ()

std::string	GetDescription () const

Detail::RFieldBase *	GetField (std::string_view fieldName)

RFieldZero *	GetFieldZero () const

RNTupleUuid	GetUuid () const

RNTupleVersion	GetVersion () const

std::shared_ptr< RCollectionNTupleWriter >	MakeCollection (std::string_view fieldName, std::unique_ptr< RNTupleModel > collectionModel)
	Ingests a model for a sub collection and attaches it to the current model.

template<typename T , typename... ArgsT>
std::shared_ptr< T >	MakeField (std::pair< std::string_view, std::string_view > fieldNameDesc, ArgsT &&... args)
	Creates a new field given a `{name, description}` pair and a corresponding tree value that is managed by a shared pointer.

template<typename T , typename... ArgsT>
std::shared_ptr< T >	MakeField (std::string_view fieldName, ArgsT &&... args)
	Creates a new field and a corresponding tree value that is managed by a shared pointer.

RNTupleModel &	operator= (const RNTupleModel &)=delete

void	SetDescription (std::string_view description)

Static Public Member Functions
static std::unique_ptr< RNTupleModel >	Create ()

Private Member Functions
void	EnsureValidFieldName (std::string_view fieldName)
	Checks that user-provided field names are valid in the context of this NTuple model.

Private Attributes
std::unique_ptr< REntry >	fDefaultEntry
	Contains field values corresponding to the created top-level fields.

std::string	fDescription
	Free text set by the user.

std::unordered_set< std::string >	fFieldNames
	Keeps track of which field names are taken.

std::unique_ptr< RFieldZero >	fFieldZero
	Hierarchy of fields consisting of simple types and collections (sub trees)

#include <ROOT/RNTupleModel.hxx>

Constructor & Destructor Documentation

◆ RNTupleModel() [1/2]

ROOT::Experimental::RNTupleModel::RNTupleModel ( )

Definition at line 39 of file RNTupleModel.cxx.

◆ RNTupleModel() [2/2]

ROOT::Experimental::RNTupleModel::RNTupleModel ( const RNTupleModel & )

delete

◆ ~RNTupleModel()

ROOT::Experimental::RNTupleModel::~RNTupleModel ( )

default

Member Function Documentation

◆ AddField() [1/3]

template<typename T >

void ROOT::Experimental::RNTupleModel::AddField	(	std::pair< std::string_view, std::string_view >	fieldNameDesc,
		T *	fromWhere
	)

inline

Throws an exception if fromWhere is null.

Definition at line 145 of file RNTupleModel.hxx.

◆ AddField() [2/3]

template<typename T >

void ROOT::Experimental::RNTupleModel::AddField	(	std::string_view	fieldName,
		T *	fromWhere
	)

inline

Throws an exception if fromWhere is null.

Definition at line 139 of file RNTupleModel.hxx.

◆ AddField() [3/3]

void ROOT::Experimental::RNTupleModel::AddField ( std::unique_ptr< Detail::RFieldBase > field )

Adds a field whose type is not known at compile time.

Thus there is no shared pointer returned.

Throws an exception if the field is null.

Definition at line 56 of file RNTupleModel.cxx.

◆ Clone()

std::unique_ptr< ROOT::Experimental::RNTupleModel > ROOT::Experimental::RNTupleModel::Clone ( ) const

Definition at line 44 of file RNTupleModel.cxx.

◆ Create()

static std::unique_ptr< RNTupleModel > ROOT::Experimental::RNTupleModel::Create ( )

inlinestatic

Definition at line 67 of file RNTupleModel.hxx.

◆ CreateEntry()

std::unique_ptr< ROOT::Experimental::REntry > ROOT::Experimental::RNTupleModel::CreateEntry ( )

Definition at line 102 of file RNTupleModel.cxx.

◆ EnsureValidFieldName()

void ROOT::Experimental::RNTupleModel::EnsureValidFieldName ( std::string_view fieldName )

private

Checks that user-provided field names are valid in the context of this NTuple model.

Throws an RException for invalid names.

Definition at line 27 of file RNTupleModel.cxx.

◆ Get()

template<typename T >

T * ROOT::Experimental::RNTupleModel::Get ( std::string_view fieldName )

inline

Definition at line 157 of file RNTupleModel.hxx.

◆ GetDefaultEntry()

REntry * ROOT::Experimental::RNTupleModel::GetDefaultEntry ( )

inline

Definition at line 170 of file RNTupleModel.hxx.

◆ GetDescription()

std::string ROOT::Experimental::RNTupleModel::GetDescription ( ) const

inline

Definition at line 173 of file RNTupleModel.hxx.

◆ GetField()

ROOT::Experimental::Detail::RFieldBase * ROOT::Experimental::RNTupleModel::GetField ( std::string_view fieldName )

Definition at line 81 of file RNTupleModel.cxx.

◆ GetFieldZero()

RFieldZero * ROOT::Experimental::RNTupleModel::GetFieldZero ( ) const

inline

Definition at line 168 of file RNTupleModel.hxx.

◆ GetUuid()

RNTupleUuid ROOT::Experimental::RNTupleModel::GetUuid ( ) const

inline

Definition at line 175 of file RNTupleModel.hxx.

◆ GetVersion()

RNTupleVersion ROOT::Experimental::RNTupleModel::GetVersion ( ) const

inline

Definition at line 172 of file RNTupleModel.hxx.

◆ MakeCollection()

std::shared_ptr< ROOT::Experimental::RCollectionNTupleWriter > ROOT::Experimental::RNTupleModel::MakeCollection	(	std::string_view	fieldName,
		std::unique_ptr< RNTupleModel >	collectionModel
	)

Ingests a model for a sub collection and attaches it to the current model.

Throws an exception if collectionModel is null.

Definition at line 67 of file RNTupleModel.cxx.

◆ MakeField() [1/2]

template<typename T , typename... ArgsT>

std::shared_ptr< T > ROOT::Experimental::RNTupleModel::MakeField	(	std::pair< std::string_view, std::string_view >	fieldNameDesc,
		ArgsT &&...	args
	)

inline

Creates a new field given a {name, description} pair and a corresponding tree value that is managed by a shared pointer.

Example: create a field with a description

#include <ROOT/RNTuple.hxx>
using ROOT::Experimental::RNTupleModel;
 
auto model = RNTupleModel::Create();
auto hadronFlavour = model->MakeField<float>({
   "hadronFlavour", "flavour from hadron ghost clustering"
});

Definition at line 121 of file RNTupleModel.hxx.

◆ MakeField() [2/2]

template<typename T , typename... ArgsT>

std::shared_ptr< T > ROOT::Experimental::RNTupleModel::MakeField	(	std::string_view	fieldName,
		ArgsT &&...	args
	)

inline

Creates a new field and a corresponding tree value that is managed by a shared pointer.

Example: create some fields and fill an RNTuple

#include <ROOT/RNTuple.hxx>
using ROOT::Experimental::RNTupleModel;
using ROOT::Experimental::RNTupleWriter;
 
#include <vector>
 
auto model = RNTupleModel::Create();
auto pt = model->MakeField<float>("pt");
auto vec = model->MakeField<std::vector<int>>("vec");
 
// The RNTuple is written to disk when the RNTupleWriter goes out of scope
{
   auto ntuple = RNTupleWriter::Recreate(std::move(model), "myNTuple", "myFile.root");
   for (int i = 0; i < 100; i++) {
      *pt = static_cast<float>(i);
      *vec = {i, i+1, i+2};
      ntuple->Fill();
   }
}

Example: create a field with an initial value

#include <ROOT/RNTuple.hxx>
using ROOT::Experimental::RNTupleModel;
 
auto model = RNTupleModel::Create();
// pt's initial value is 42.0
auto pt = model->MakeField<float>("pt", 42.0);

Definition at line 103 of file RNTupleModel.hxx.

◆ operator=()

RNTupleModel & ROOT::Experimental::RNTupleModel::operator= ( const RNTupleModel & )

delete

◆ SetDescription()

void ROOT::Experimental::RNTupleModel::SetDescription ( std::string_view description )

inline

Definition at line 174 of file RNTupleModel.hxx.

Member Data Documentation

◆ fDefaultEntry

std::unique_ptr<REntry> ROOT::Experimental::RNTupleModel::fDefaultEntry

private

Contains field values corresponding to the created top-level fields.

Definition at line 49 of file RNTupleModel.hxx.

◆ fDescription

std::string ROOT::Experimental::RNTupleModel::fDescription

private

Free text set by the user.

Definition at line 58 of file RNTupleModel.hxx.

◆ fFieldNames

std::unordered_set<std::string> ROOT::Experimental::RNTupleModel::fFieldNames

private

Keeps track of which field names are taken.

Definition at line 51 of file RNTupleModel.hxx.

◆ fFieldZero

std::unique_ptr<RFieldZero> ROOT::Experimental::RNTupleModel::fFieldZero

private

Hierarchy of fields consisting of simple types and collections (sub trees)

Definition at line 47 of file RNTupleModel.hxx.

Libraries for ROOT::Experimental::RNTupleModel:

[legend]

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

tree/ntuple/v7/inc/ROOT/RNTupleModel.hxx
tree/ntuple/v7/src/RNTupleModel.cxx

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Constructor & Destructor Documentation

◆ RNTupleModel() [1/2]

◆ RNTupleModel() [2/2]

◆ ~RNTupleModel()

Member Function Documentation

◆ AddField() [1/3]

◆ AddField() [2/3]

◆ AddField() [3/3]

◆ Clone()

◆ Create()

◆ CreateEntry()

◆ EnsureValidFieldName()

◆ Get()

◆ GetDefaultEntry()

◆ GetDescription()

◆ GetField()

◆ GetFieldZero()

◆ GetUuid()

◆ GetVersion()

◆ MakeCollection()

◆ MakeField() [1/2]

◆ MakeField() [2/2]

◆ operator=()

◆ SetDescription()

Member Data Documentation

◆ fDefaultEntry

◆ fDescription

◆ fFieldNames

◆ fFieldZero