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Reference Guide
ROOT::Experimental::RNTupleModel Class Reference

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. More...
 
template<typename T >
void AddField (std::string_view fieldName, T *fromWhere)
 Throws an exception if fromWhere is null. More...
 
void AddField (std::unique_ptr< Detail::RFieldBase > field)
 Adds a field whose type is not known at compile time. More...
 
std::unique_ptr< RNTupleModelClone () const
 
std::unique_ptr< REntryCreateEntry ()
 
template<typename T >
T * Get (std::string_view fieldName)
 
REntryGetDefaultEntry ()
 
std::string GetDescription () const
 
Detail::RFieldBaseGetField (std::string_view fieldName)
 
RFieldZeroGetFieldZero () const
 
RNTupleUuid GetUuid () const
 
RNTupleVersion GetVersion () const
 
std::shared_ptr< RCollectionNTupleWriterMakeCollection (std::string_view fieldName, std::unique_ptr< RNTupleModel > collectionModel)
 Ingests a model for a sub collection and attaches it to the current model. More...
 
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. More...
 
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. More...
 
RNTupleModeloperator= (const RNTupleModel &)=delete
 
void SetDescription (std::string_view description)
 

Static Public Member Functions

static std::unique_ptr< RNTupleModelCreate ()
 

Private Member Functions

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

Private Attributes

std::unique_ptr< REntryfDefaultEntry
 Contains field values corresponding to the created top-level fields. More...
 
std::string fDescription
 Free text set by the user. More...
 
std::unordered_set< std::string > fFieldNames
 Keeps track of which field names are taken. More...
 
std::unique_ptr< RFieldZerofFieldZero
 Hierarchy of fields consisting of simple types and collections (sub trees) More...
 

#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>
auto model = RNTupleModel::Create();
auto hadronFlavour = model->MakeField<float>({
"hadronFlavour", "flavour from hadron ghost clustering"
});
The RNTupleModel encapulates the schema of an ntuple.
static std::unique_ptr< RNTupleModel > Create()

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>
#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();
}
}
An RNTuple that gets filled with entries (data) and writes them to storage.
Definition: RNTuple.hxx:351
static std::unique_ptr< RNTupleWriter > Recreate(std::unique_ptr< RNTupleModel > model, std::string_view ntupleName, std::string_view storage, const RNTupleWriteOptions &options=RNTupleWriteOptions())
Throws an exception if the model is null.
Definition: RNTuple.cxx:305
TPaveText * pt
Definition: civetweb.c:2228

Example: create a field with an initial value

#include <ROOT/RNTuple.hxx>
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.


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