A field for fixed-size arrays that are represented as RVecs in memory.

This class is used only for reading. In particular, it helps exposing arbitrarily-nested std::array on-disk fields as RVecs for usage in RDataFrame.

Definition at line 1236 of file RField.hxx.

Public Member Functions
	RArrayAsRVecField (const RArrayAsRVecField &other)=delete

	RArrayAsRVecField (RArrayAsRVecField &&other)=default

	RArrayAsRVecField (std::string_view fieldName, std::unique_ptr< RFieldBase > itemField, std::size_t arrayLength)
	Constructor of the field.

	~RArrayAsRVecField () final=default

void	AcceptVisitor (Detail::RFieldVisitor &visitor) const final

std::size_t	GetAlignment () const final
	As a rule of thumb, the alignment is equal to the size of the type.

std::size_t	GetValueSize () const final
	The number of bytes taken by a value of the appropriate type.

RArrayAsRVecField &	operator= (const RArrayAsRVecField &other)=delete

RArrayAsRVecField &	operator= (RArrayAsRVecField &&other)=default

std::vector< RFieldBase::RValue >	SplitValue (const RFieldBase::RValue &value) const final
	Creates the list of direct child values given a value for this field.

Public Member Functions inherited from ROOT::Experimental::RFieldBase
	RFieldBase (const RFieldBase &)=delete

	RFieldBase (RFieldBase &&)=default

	RFieldBase (std::string_view name, std::string_view type, ENTupleStructure structure, bool isSimple, std::size_t nRepetitions=0)
	The constructor creates the underlying column objects and connects them to either a sink or a source.

virtual	~RFieldBase ()=default

RSchemaIterator	begin ()

RValue	BindValue (std::shared_ptr< void > objPtr)
	Creates a value from a memory location with an already constructed object.

RConstSchemaIterator	cbegin () const

RConstSchemaIterator	cend () const

std::unique_ptr< RFieldBase >	Clone (std::string_view newName) const
	Copies the field and its sub fields using a possibly new name and a new, unconnected set of columns.

RBulk	CreateBulk ()
	The returned bulk is initially empty; RBulk::ReadBulk will construct the array of values.

template<typename T >
std::unique_ptr< T, typename RCreateObjectDeleter< T >::deleter >	CreateObject () const
	Generates an object of the field type and allocates new initialized memory according to the type.

template<>
std::unique_ptr< void, typename RFieldBase::RCreateObjectDeleter< void >::deleter >	CreateObject () const

template<>
std::unique_ptr< void, typename ROOT::Experimental::RFieldBase::RCreateObjectDeleter< void >::deleter >	CreateObject () const

RValue	CreateValue ()
	Generates an object of the field type and wraps the created object in a shared pointer and returns it an RValue connected to the field.

RSchemaIterator	end ()

const ColumnRepresentation_t &	GetColumnRepresentative () const
	Returns the fColumnRepresentative pointee or, if unset, the field's default representative.

std::string	GetDescription () const
	Get the field's description.

std::string	GetFieldName () const

virtual std::uint32_t	GetFieldVersion () const
	Indicates an evolution of the mapping scheme from C++ type to columns.

NTupleSize_t	GetNElements () const

std::size_t	GetNRepetitions () const

DescriptorId_t	GetOnDiskId () const

std::uint32_t	GetOnDiskTypeVersion () const
	Return the C++ type version stored in the field descriptor; only valid after a call to `ConnectPageSource()`

const RFieldBase *	GetParent () const

std::string	GetQualifiedFieldName () const
	Returns the field name and parent field names separated by dots ("grandparent.parent.child")

EState	GetState () const

ENTupleStructure	GetStructure () const

std::vector< RFieldBase * >	GetSubFields ()

std::vector< const RFieldBase * >	GetSubFields () const

int	GetTraits () const

std::string	GetTypeAlias () const

std::string	GetTypeName () const

virtual std::uint32_t	GetTypeVersion () const
	Indicates an evolution of the C++ type itself.

bool	HasDefaultColumnRepresentative () const
	Whether or not an explicit column representative was set.

bool	HasReadCallbacks () const

bool	IsSimple () const

RFieldBase &	operator= (const RFieldBase &)=delete

RFieldBase &	operator= (RFieldBase &&)=default

void	SetColumnRepresentative (const ColumnRepresentation_t &representative)
	Fixes a column representative.

void	SetDescription (std::string_view description)

void	SetOnDiskId (DescriptorId_t id)

Protected Member Functions
std::unique_ptr< RFieldBase >	CloneImpl (std::string_view newName) const final
	The size of a value of this field, i.e. an RVec.

void	ConstructValue (void *where) const final
	Constructs value in a given location of size at least GetValueSize(). Called by the base class' CreateValue().

void	GenerateColumnsImpl () final
	Creates the backing columns corresponsing to the field type for writing.

void	GenerateColumnsImpl (const RNTupleDescriptor &) final
	Creates the backing columns corresponsing to the field type for reading.

std::unique_ptr< RDeleter >	GetDeleter () const final
	Returns an RRVecField::RRVecDeleter.

void	ReadGlobalImpl (NTupleSize_t globalIndex, void *to) final

void	ReadInClusterImpl (RClusterIndex clusterIndex, void *to) final

Protected Member Functions inherited from ROOT::Experimental::RFieldBase
size_t	AddReadCallback (ReadCallback_t func)
	Set a user-defined function to be called after reading a value, giving a chance to inspect and/or modify the value object.

std::size_t	Append (const void *from)
	Write the given value into columns.

virtual std::size_t	AppendImpl (const void *from)
	Operations on values of complex types, e.g.

void	Attach (std::unique_ptr< RFieldBase > child)
	Add a new subfield to the list of nested fields.

void	AutoAdjustColumnTypes (const RNTupleWriteOptions &options)
	When connecting a field to a page sink, the field's default column representation is subject to adjustment according to the write options.

virtual void	CommitClusterImpl ()

const ColumnRepresentation_t &	EnsureCompatibleColumnTypes (const RNTupleDescriptor &desc) const
	Returns the on-disk column types found in the provided descriptor for fOnDiskId.

virtual const RColumnRepresentations &	GetColumnRepresentations () const
	Implementations in derived classes should return a static RColumnRepresentations object.

virtual void	OnConnectPageSource ()
	Called by `ConnectPageSource()` only once connected; derived classes may override this as appropriate.

void	Read (NTupleSize_t globalIndex, void *to)
	Populate a single value with data from the field.

void	Read (RClusterIndex clusterIndex, void *to)

std::size_t	ReadBulk (const RBulkSpec &bulkSpec)
	Returns the number of newly available values, that is the number of bools in bulkSpec.fMaskAvail that flipped from false to true.

virtual std::size_t	ReadBulkImpl (const RBulkSpec &bulkSpec)
	General implementation of bulk read.

void	RemoveReadCallback (size_t idx)

Private Attributes
std::size_t	fArrayLength
	The size of a child field's item.

std::unique_ptr< RDeleter >	fItemDeleter

std::size_t	fItemSize
	Sub field deleter or nullptr for simple fields.

std::size_t	fValueSize
	The length of the arrays in this field.

Additional Inherited Members
Public Types inherited from ROOT::Experimental::RFieldBase
using	ColumnRepresentation_t = std::vector< EColumnType >

enum class	EState { kUnconnected , kConnectedToSink , kConnectedToSource }
	During its lifetime, a field undergoes the following possible state transitions: More...

using	RConstSchemaIterator = RSchemaIteratorTemplate< true >

using	RSchemaIterator = RSchemaIteratorTemplate< false >

Static Public Member Functions inherited from ROOT::Experimental::RFieldBase
static std::vector< RCheckResult >	Check (const std::string &fieldName, const std::string &typeName)
	Checks if the given type is supported by RNTuple.

static RResult< std::unique_ptr< RFieldBase > >	Create (const std::string &fieldName, const std::string &typeName)
	Factory method to resurrect a field from the stored on-disk type information.

static RResult< void >	EnsureValidFieldName (std::string_view fieldName)
	Check whether a given string is a valid field name.

Static Public Attributes inherited from ROOT::Experimental::RFieldBase
static constexpr std::uint32_t	kInvalidTypeVersion = -1U

static constexpr int	kTraitMappable = 0x04
	A field of a fundamental type that can be directly mapped via `RField<T>::Map()`, i.e.

static constexpr int	kTraitTriviallyConstructible = 0x01
	No constructor needs to be called, i.e.

static constexpr int	kTraitTriviallyDestructible = 0x02
	The type is cleaned up just by freeing its memory. I.e. the destructor performs a no-op.

static constexpr int	kTraitTrivialType = kTraitTriviallyConstructible \| kTraitTriviallyDestructible
	Shorthand for types that are both trivially constructible and destructible.

Static Protected Member Functions inherited from ROOT::Experimental::RFieldBase
static std::size_t	CallAppendOn (RFieldBase &other, const void *from)
	Allow derived classes to call Append and Read on other (sub) fields.

static void	CallConstructValueOn (const RFieldBase &other, void *where)
	Allow derived classes to call ConstructValue(void *) and GetDeleter on other (sub) fields.

static void	CallReadOn (RFieldBase &other, NTupleSize_t globalIndex, void *to)

static void	CallReadOn (RFieldBase &other, RClusterIndex clusterIndex, void *to)

static RResult< std::unique_ptr< RFieldBase > >	Create (const std::string &fieldName, const std::string &canonicalType, const std::string &typeAlias, bool fContinueOnError=false)
	Factory method to resurrect a field from the stored on-disk type information.

static std::unique_ptr< RDeleter >	GetDeleterOf (const RFieldBase &other)

static Internal::RColumn *	GetPrincipalColumnOf (const RFieldBase &other)
	Fields may need direct access to the principal column of their sub fields, e.g. in RRVecField::ReadBulk.

Protected Attributes inherited from ROOT::Experimental::RFieldBase
const ColumnRepresentation_t *	fColumnRepresentative = nullptr
	Points into the static vector GetColumnRepresentations().GetSerializationTypes() when SetColumnRepresentative is called.

std::vector< std::unique_ptr< Internal::RColumn > >	fColumns
	The columns are connected either to a sink or to a source (not to both); they are owned by the field.

std::uint32_t	fOnDiskTypeVersion = kInvalidTypeVersion
	C++ type version cached from the descriptor after a call to `ConnectPageSource()`

RFieldBase *	fParent
	Sub fields point to their mother field.

Internal::RColumn *	fPrincipalColumn
	Points into fColumns.

std::vector< ReadCallback_t >	fReadCallbacks
	List of functions to be called after reading a value.

std::vector< std::unique_ptr< RFieldBase > >	fSubFields
	Collections and classes own sub fields.

int	fTraits = 0
	Properties of the type that allow for optimizations of collections of that type.

std::string	fTypeAlias
	A typedef or using name that was used when creating the field.

#include <ROOT/RField.hxx>

Inheritance diagram for ROOT::Experimental::RArrayAsRVecField:

[legend]

Constructor & Destructor Documentation

◆ RArrayAsRVecField() [1/3]

ROOT::Experimental::RArrayAsRVecField::RArrayAsRVecField	(	std::string_view	fieldName,
		std::unique_ptr< RFieldBase >	itemField,
		std::size_t	arrayLength
	)

Constructor of the field.

the itemField argument represents the inner item of the on-disk array, i.e. for an std::array<float> it is the float field and not the std::array itself.

Definition at line 2710 of file RField.cxx.

◆ RArrayAsRVecField() [2/3]

ROOT::Experimental::RArrayAsRVecField::RArrayAsRVecField ( const RArrayAsRVecField & other )

delete

◆ RArrayAsRVecField() [3/3]

ROOT::Experimental::RArrayAsRVecField::RArrayAsRVecField ( RArrayAsRVecField && other )

default

◆ ~RArrayAsRVecField()

ROOT::Experimental::RArrayAsRVecField::~RArrayAsRVecField ( )

finaldefault

Member Function Documentation

◆ AcceptVisitor()

void ROOT::Experimental::RArrayAsRVecField::AcceptVisitor ( Detail::RFieldVisitor & visitor ) const

finalvirtual

Reimplemented from ROOT::Experimental::RFieldBase.

Definition at line 2846 of file RField.cxx.

◆ CloneImpl()

std::unique_ptr< ROOT::Experimental::RFieldBase > ROOT::Experimental::RArrayAsRVecField::CloneImpl ( std::string_view newName ) const

finalprotectedvirtual

The size of a value of this field, i.e. an RVec.

Implements ROOT::Experimental::RFieldBase.

Definition at line 2725 of file RField.cxx.

◆ ConstructValue()

void ROOT::Experimental::RArrayAsRVecField::ConstructValue ( void * where ) const

finalprotectedvirtual

Constructs value in a given location of size at least GetValueSize(). Called by the base class' CreateValue().

Implements ROOT::Experimental::RFieldBase.

Definition at line 2731 of file RField.cxx.

◆ GenerateColumnsImpl() [1/2]

void ROOT::Experimental::RArrayAsRVecField::GenerateColumnsImpl ( )

inlinefinalprotectedvirtual

Creates the backing columns corresponsing to the field type for writing.

Implements ROOT::Experimental::RFieldBase.

Definition at line 1246 of file RField.hxx.

◆ GenerateColumnsImpl() [2/2]

void ROOT::Experimental::RArrayAsRVecField::GenerateColumnsImpl ( const RNTupleDescriptor & desc )

inlinefinalprotectedvirtual

Creates the backing columns corresponsing to the field type for reading.

The method should to check, using the page source and fOnDiskId, if the column types match and throw if they don't.

Implements ROOT::Experimental::RFieldBase.

Definition at line 1247 of file RField.hxx.

◆ GetAlignment()

size_t ROOT::Experimental::RArrayAsRVecField::GetAlignment ( ) const

finalvirtual

As a rule of thumb, the alignment is equal to the size of the type.

There are, however, various exceptions to this rule depending on OS and CPU architecture. So enforce the alignment to be explicitly spelled out.

Implements ROOT::Experimental::RFieldBase.

Definition at line 2829 of file RField.cxx.

◆ GetDeleter()

std::unique_ptr< ROOT::Experimental::RFieldBase::RDeleter > ROOT::Experimental::RArrayAsRVecField::GetDeleter ( ) const

finalprotectedvirtual

Returns an RRVecField::RRVecDeleter.

Reimplemented from ROOT::Experimental::RFieldBase.

Definition at line 2782 of file RField.cxx.

◆ GetValueSize()

std::size_t ROOT::Experimental::RArrayAsRVecField::GetValueSize ( ) const

inlinefinalvirtual

The number of bytes taken by a value of the appropriate type.

Implements ROOT::Experimental::RFieldBase.

Definition at line 1269 of file RField.hxx.

◆ operator=() [1/2]

RArrayAsRVecField & ROOT::Experimental::RArrayAsRVecField::operator= ( const RArrayAsRVecField & other )

delete

◆ operator=() [2/2]

RArrayAsRVecField & ROOT::Experimental::RArrayAsRVecField::operator= ( RArrayAsRVecField && other )

default

◆ ReadGlobalImpl()

void ROOT::Experimental::RArrayAsRVecField::ReadGlobalImpl	(	NTupleSize_t	globalIndex,
		void *	to
	)

finalprotectedvirtual

Reimplemented from ROOT::Experimental::RFieldBase.

Definition at line 2791 of file RField.cxx.

◆ ReadInClusterImpl()

void ROOT::Experimental::RArrayAsRVecField::ReadInClusterImpl	(	RClusterIndex	clusterIndex,
		void *	to
	)

finalprotectedvirtual

Reimplemented from ROOT::Experimental::RFieldBase.

Definition at line 2808 of file RField.cxx.

◆ SplitValue()

std::vector< ROOT::Experimental::RFieldBase::RValue > ROOT::Experimental::RArrayAsRVecField::SplitValue ( const RFieldBase::RValue & value ) const

finalvirtual

Creates the list of direct child values given a value for this field.

E.g. a single value for the correct variant or all the elements of a collection. The default implementation assumes no sub values and returns an empty vector.

Reimplemented from ROOT::Experimental::RFieldBase.

Definition at line 2835 of file RField.cxx.

Member Data Documentation

◆ fArrayLength

std::size_t ROOT::Experimental::RArrayAsRVecField::fArrayLength

private

The size of a child field's item.

Definition at line 1240 of file RField.hxx.

◆ fItemDeleter

std::unique_ptr<RDeleter> ROOT::Experimental::RArrayAsRVecField::fItemDeleter

private

Definition at line 1238 of file RField.hxx.

◆ fItemSize

std::size_t ROOT::Experimental::RArrayAsRVecField::fItemSize

private

Sub field deleter or nullptr for simple fields.

Definition at line 1239 of file RField.hxx.

◆ fValueSize

std::size_t ROOT::Experimental::RArrayAsRVecField::fValueSize

private

The length of the arrays in this field.

Definition at line 1241 of file RField.hxx.

Libraries for ROOT::Experimental::RArrayAsRVecField:

[legend]

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

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

Public Member Functions

Protected Member Functions

Private Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ RArrayAsRVecField() [1/3]

◆ RArrayAsRVecField() [2/3]

◆ RArrayAsRVecField() [3/3]

◆ ~RArrayAsRVecField()

Member Function Documentation

◆ AcceptVisitor()

◆ CloneImpl()

◆ ConstructValue()

◆ GenerateColumnsImpl() [1/2]

◆ GenerateColumnsImpl() [2/2]

◆ GetAlignment()

◆ GetDeleter()

◆ GetValueSize()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ ReadGlobalImpl()

◆ ReadInClusterImpl()

◆ SplitValue()

Member Data Documentation

◆ fArrayLength

◆ fItemDeleter

◆ fItemSize

◆ fValueSize