A field translates read and write calls from/to underlying columns to/from tree values.

A field is a serializable C++ type or a container for a collection of sub fields. The RFieldBase and its type-safe descendants provide the object to column mapper. They map C++ objects to primitive columns. The mapping is trivial for simple types such as 'double'. Complex types resolve to multiple primitive columns. The field knows based on its type and the field name the type(s) and name(s) of the columns.

Note: the class hierarchy starting at RFieldBase is not meant to be extended by user-provided child classes. This is and can only be partially enforced through C++.

Definition at line 94 of file RField.hxx.

Classes
class	RBulk
	Similar to RValue but manages an array of consecutive values. More...

struct	RBulkSpec
	Input parameter to ReadBulk() and ReadBulkImpl(). See RBulk class for more information. More...

struct	RCheckResult
	Used in the return value of the Check() method. More...

class	RColumnRepresentations
	Some fields have multiple possible column representations, e.g. More...

struct	RCreateObjectDeleter

struct	RCreateObjectDeleter< void >

class	RDeleter
	A functor to release the memory acquired by CreateValue (memory and constructor). More...

class	RSchemaIteratorTemplate
	Iterates over the sub tree of fields in depth-first search order. More...

struct	RSharedPtrDeleter

class	RTypedDeleter
	A deleter for templated RFieldBase descendents where the value type is known. More...

class	RValue
	Points to an object with RNTuple I/O support and keeps a pointer to the corresponding field. More...

Public Types
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 >

Public Member Functions
	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

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

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 ()

virtual size_t	GetAlignment () const =0
	As a rule of thumb, the alignment is equal to the size of the type.

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.

virtual size_t	GetValueSize () const =0
	The number of bytes taken by a value of the appropriate type.

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)

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

Static Public Member Functions
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
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.

Protected Member Functions
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 std::unique_ptr< RFieldBase >	CloneImpl (std::string_view newName) const =0
	Called by Clone(), which additionally copies the on-disk ID.

virtual void	CommitClusterImpl ()

virtual void	ConstructValue (void *where) const =0
	Constructs value in a given location of size at least GetValueSize(). Called by the base class' CreateValue().

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

virtual void	GenerateColumnsImpl ()=0
	Creates the backing columns corresponsing to the field type for writing.

virtual void	GenerateColumnsImpl (const RNTupleDescriptor &desc)=0
	Creates the backing columns corresponsing to the field type for reading.

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

virtual std::unique_ptr< RDeleter >	GetDeleter () const

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.

virtual void	ReadGlobalImpl (NTupleSize_t globalIndex, void *to)

virtual void	ReadInClusterImpl (RClusterIndex clusterIndex, void *to)

void	RemoveReadCallback (size_t idx)

Static Protected Member Functions
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
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.

Private Types
using	ReadCallback_t = std::function< void(void *)>

Private Member Functions
void	CommitCluster ()
	Flushes data from active columns to disk and calls CommitClusterImpl.

void	ConnectPageSink (Internal::RPageSink &pageSink, NTupleSize_t firstEntry=0)
	Fields and their columns live in the void until connected to a physical page storage.

void	ConnectPageSource (Internal::RPageSource &pageSource)
	Connects the field and its sub field tree to the given page source.

void *	CreateObjectRawPtr () const
	Factory method for the field's type. The caller owns the returned pointer.

NTupleSize_t	EntryToColumnElementIndex (NTupleSize_t globalIndex) const
	Translate an entry index to a column element index of the principal column and viceversa.

void	InvokeReadCallbacks (void *target)

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

bool	fIsSimple
	A field qualifies as simple if it is both mappable and has no post-read callback.

std::string	fName
	The field name relative to its parent field.

std::size_t	fNRepetitions
	For fixed sized arrays, the array length.

DescriptorId_t	fOnDiskId = kInvalidDescriptorId
	When the columns are connected to a page source or page sink, the field represents a field id in the corresponding RNTuple descriptor.

EState	fState = EState::kUnconnected
	Changed by ConnectTo[Sink,Source], reset by Clone()

ENTupleStructure	fStructure
	The role of this field in the data model structure.

std::string	fType
	The C++ type captured by this field.

Friends
void	Internal::CallCommitClusterOnField (RFieldBase &)

void	Internal::CallConnectPageSinkOnField (RFieldBase &, Internal::RPageSink &, NTupleSize_t)

void	Internal::CallConnectPageSourceOnField (RFieldBase &, Internal::RPageSource &)

struct	ROOT::Experimental::Internal::RFieldCallbackInjector

class	ROOT::Experimental::RCollectionField

#include <ROOT/RField.hxx>

Inheritance diagram for ROOT::Experimental::RFieldBase:

[legend]

Member Typedef Documentation

◆ ColumnRepresentation_t

using ROOT::Experimental::RFieldBase::ColumnRepresentation_t = std::vector<EColumnType>

Definition at line 149 of file RField.hxx.

◆ RConstSchemaIterator

using ROOT::Experimental::RFieldBase::RConstSchemaIterator = RSchemaIteratorTemplate<true>

Definition at line 596 of file RField.hxx.

◆ ReadCallback_t

using ROOT::Experimental::RFieldBase::ReadCallback_t = std::function<void(void *)>

private

Definition at line 100 of file RField.hxx.

◆ RSchemaIterator

using ROOT::Experimental::RFieldBase::RSchemaIterator = RSchemaIteratorTemplate<false>

Definition at line 595 of file RField.hxx.

Member Enumeration Documentation

◆ EState

enum class ROOT::Experimental::RFieldBase::EState

strong

During its lifetime, a field undergoes the following possible state transitions:

[*] --> Unconnected --> ConnectedToSink -— | | | | --> ConnectedToSource —> [*]

| |

Enumerator
kUnconnected
kConnectedToSink
kConnectedToSource

Definition at line 158 of file RField.hxx.

Constructor & Destructor Documentation

◆ RFieldBase() [1/3]

ROOT::Experimental::RFieldBase::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.

If isSimple is true, the trait kTraitMappable is automatically set on construction. However, the field might be demoted to non-simple if a post-read callback is set.

Definition at line 511 of file RField.cxx.

◆ RFieldBase() [2/3]

ROOT::Experimental::RFieldBase::RFieldBase ( const RFieldBase & )

delete

◆ RFieldBase() [3/3]

ROOT::Experimental::RFieldBase::RFieldBase ( RFieldBase && )

default

◆ ~RFieldBase()

virtual ROOT::Experimental::RFieldBase::~RFieldBase ( )

virtualdefault

Member Function Documentation

◆ AcceptVisitor()

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

virtual

◆ AddReadCallback()

size_t ROOT::Experimental::RFieldBase::AddReadCallback ( ReadCallback_t func )

protected

Set a user-defined function to be called after reading a value, giving a chance to inspect and/or modify the value object.

Returns an index that can be used to remove the callback.

Definition at line 959 of file RField.cxx.

◆ Append()

std::size_t ROOT::Experimental::RFieldBase::Append ( const void * from )

inlineprotected

Write the given value into columns.

The value object has to be of the same type as the field. Returns the number of uncompressed bytes written.

Definition at line 450 of file RField.hxx.

◆ AppendImpl()

std::size_t ROOT::Experimental::RFieldBase::AppendImpl ( const void * from )

protectedvirtual

Operations on values of complex types, e.g.

ones that involve multiple columns or for which no direct column type exists.

Definition at line 799 of file RField.cxx.

◆ Attach()

void ROOT::Experimental::RFieldBase::Attach ( std::unique_ptr< RFieldBase > child )

protected

Add a new subfield to the list of nested fields.

Definition at line 850 of file RField.cxx.

◆ AutoAdjustColumnTypes()

void ROOT::Experimental::RFieldBase::AutoAdjustColumnTypes ( const RNTupleWriteOptions & options )

protected

When connecting a field to a page sink, the field's default column representation is subject to adjustment according to the write options.

E.g., if compression is turned off, encoded columns are changed to their unencoded counterparts.

Definition at line 972 of file RField.cxx.

◆ begin()

RSchemaIterator ROOT::Experimental::RFieldBase::begin ( )

inline

Definition at line 700 of file RField.hxx.

◆ BindValue()

RValue ROOT::Experimental::RFieldBase::BindValue ( std::shared_ptr< void > objPtr )

inline

Creates a value from a memory location with an already constructed object.

Definition at line 651 of file RField.hxx.

◆ CallAppendOn()

static std::size_t ROOT::Experimental::RFieldBase::CallAppendOn	(	RFieldBase &	other,
		const void *	from
	)

inlinestaticprotected

Allow derived classes to call Append and Read on other (sub) fields.

Definition at line 509 of file RField.hxx.

◆ CallConstructValueOn()

static void ROOT::Experimental::RFieldBase::CallConstructValueOn	(	const RFieldBase &	other,
		void *	where
	)

inlinestaticprotected

Allow derived classes to call ConstructValue(void *) and GetDeleter on other (sub) fields.

Definition at line 436 of file RField.hxx.

◆ CallReadOn() [1/2]

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

inlinestaticprotected

Definition at line 511 of file RField.hxx.

◆ CallReadOn() [2/2]

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

inlinestaticprotected

Definition at line 510 of file RField.hxx.

◆ cbegin()

RConstSchemaIterator ROOT::Experimental::RFieldBase::cbegin ( ) const

inline

Definition at line 705 of file RField.hxx.

◆ cend()

RConstSchemaIterator ROOT::Experimental::RFieldBase::cend ( ) const

inline

Definition at line 709 of file RField.hxx.

◆ Check()

std::vector< ROOT::Experimental::RFieldBase::RCheckResult > ROOT::Experimental::RFieldBase::Check	(	const std::string &	fieldName,
		const std::string &	typeName
	)

static

Checks if the given type is supported by RNTuple.

In case of success, the result vector is empty. Otherwise there is an error record for each failing sub field (sub type).

Definition at line 544 of file RField.cxx.

◆ Clone()

std::unique_ptr< ROOT::Experimental::RFieldBase > ROOT::Experimental::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.

Definition at line 788 of file RField.cxx.

◆ CloneImpl()

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

protectedpure virtual

Called by Clone(), which additionally copies the on-disk ID.

◆ CommitCluster()

void ROOT::Experimental::RFieldBase::CommitCluster ( )

private

Flushes data from active columns to disk and calls CommitClusterImpl.

Definition at line 893 of file RField.cxx.

◆ CommitClusterImpl()

virtual void ROOT::Experimental::RFieldBase::CommitClusterImpl ( )

inlineprotectedvirtual

Reimplemented in ROOT::Experimental::RProxiedCollectionField, ROOT::Experimental::RVectorField, ROOT::Experimental::RRVecField, ROOT::Experimental::RVariantField, ROOT::Experimental::RNullableField, and ROOT::Experimental::RCollectionField.

Definition at line 523 of file RField.hxx.

◆ ConnectPageSink()

void ROOT::Experimental::RFieldBase::ConnectPageSink	(	Internal::RPageSink &	pageSink,
		NTupleSize_t	firstEntry = `0`
	)

private

Fields and their columns live in the void until connected to a physical page storage.

Only once connected, data can be read or written. In order to find the field in the page storage, the field's on-disk ID has to be set.

Parameters

firstEntry The global index of the first entry with on-disk data for the connected field

Definition at line 1007 of file RField.cxx.

◆ ConnectPageSource()

void ROOT::Experimental::RFieldBase::ConnectPageSource ( Internal::RPageSource & pageSource )

private

Connects the field and its sub field tree to the given page source.

Once connected, data can be read. Only unconnected fields may be connected, i.e. the method is not idempotent. The field ID has to be set prior to calling this function. For sub fields, a field ID may or may not be set. If the field ID is unset, it will be determined using the page source descriptor, based on the parent field ID and the sub field name.

Definition at line 1027 of file RField.cxx.

◆ ConstructValue()

virtual void ROOT::Experimental::RFieldBase::ConstructValue ( void * where ) const

protectedpure virtual

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

◆ Create() [1/2]

ROOT::Experimental::RResult< std::unique_ptr< ROOT::Experimental::RFieldBase > > ROOT::Experimental::RFieldBase::Create	(	const std::string &	fieldName,
		const std::string &	canonicalType,
		const std::string &	typeAlias,
		bool	fContinueOnError = `false`
	)

staticprotected

Factory method to resurrect a field from the stored on-disk type information.

This overload takes an already normalized type name and type alias TODO(jalopezg): this overload may eventually be removed leaving only the RFieldBase::Create() that takes a single type name

Definition at line 565 of file RField.cxx.

◆ Create() [2/2]

ROOT::Experimental::RResult< std::unique_ptr< ROOT::Experimental::RFieldBase > > ROOT::Experimental::RFieldBase::Create	(	const std::string &	fieldName,
		const std::string &	typeName
	)

static

Factory method to resurrect a field from the stored on-disk type information.

Definition at line 536 of file RField.cxx.

◆ CreateBulk()

RBulk ROOT::Experimental::RFieldBase::CreateBulk ( )

inline

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

Definition at line 649 of file RField.hxx.

◆ CreateObject() [1/3]

template<typename T >

std::unique_ptr< T, typename RFieldBase::RCreateObjectDeleter< T >::deleter > ROOT::Experimental::RFieldBase::CreateObject

Generates an object of the field type and allocates new initialized memory according to the type.

Implemented at the end of this header because the implementation is using RField<T>::TypeName() The returned object can be released with delete, i.e. it is valid to call auto ptr = field->CreateObject(); delete ptr.release();

Note that CreateObject<void> is supported. The returned unique_ptr has a custom deleter that reports an error if it is called. The intended use of the returned unique_ptr<void> is to call release(). In this way, the transfer of pointer ownership is explicit.

Definition at line 2853 of file RField.hxx.

◆ CreateObject() [2/3]

template<>

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

◆ CreateObject() [3/3]

template<>

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

Definition at line 496 of file RField.cxx.

◆ CreateObjectRawPtr()

void * ROOT::Experimental::RFieldBase::CreateObjectRawPtr ( ) const

private

Factory method for the field's type. The caller owns the returned pointer.

Definition at line 830 of file RField.cxx.

◆ CreateValue()

ROOT::Experimental::RFieldBase::RValue ROOT::Experimental::RFieldBase::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.

Definition at line 838 of file RField.cxx.

◆ end()

RSchemaIterator ROOT::Experimental::RFieldBase::end ( )

inline

Definition at line 704 of file RField.hxx.

◆ EnsureCompatibleColumnTypes()

const ROOT::Experimental::RFieldBase::ColumnRepresentation_t & ROOT::Experimental::RFieldBase::EnsureCompatibleColumnTypes ( const RNTupleDescriptor & desc ) const

protected

Returns the on-disk column types found in the provided descriptor for fOnDiskId.

Throws an exception if the types don't match any of the deserialization types from GetColumnRepresentations().

Definition at line 935 of file RField.cxx.

◆ EnsureValidFieldName()

ROOT::Experimental::RResult< void > ROOT::Experimental::RFieldBase::EnsureValidFieldName ( std::string_view fieldName )

static

Check whether a given string is a valid field name.

Definition at line 771 of file RField.cxx.

◆ EntryToColumnElementIndex()

ROOT::Experimental::NTupleSize_t ROOT::Experimental::RFieldBase::EntryToColumnElementIndex ( NTupleSize_t globalIndex ) const

private

Translate an entry index to a column element index of the principal column and viceversa.

These functions take into account the role and number of repetitions on each level of the field hierarchy as follows:

Top level fields: element index == entry index
Record fields propagate their principal column index to the principal columns of direct descendant fields
Collection and variant fields set the principal column index of their childs to 0

The column element index also depends on the number of repetitions of each field in the hierarchy, e.g., given a field with type std::array<std::array<float, 4>, 2>, this function returns 8 for the inner-most field.

Definition at line 861 of file RField.cxx.

◆ GenerateColumnsImpl() [1/2]

virtual void ROOT::Experimental::RFieldBase::GenerateColumnsImpl ( )

protectedpure virtual

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

◆ GenerateColumnsImpl() [2/2]

virtual void ROOT::Experimental::RFieldBase::GenerateColumnsImpl ( const RNTupleDescriptor & desc )

protectedpure virtual

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.

◆ GetAlignment()

virtual size_t ROOT::Experimental::RFieldBase::GetAlignment ( ) const

pure virtual

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.

◆ GetColumnRepresentations()

const ROOT::Experimental::RFieldBase::RColumnRepresentations & ROOT::Experimental::RFieldBase::GetColumnRepresentations ( ) const

protectedvirtual

Implementations in derived classes should return a static RColumnRepresentations object.

The default implementation does not attach any columns to the field.

Definition at line 782 of file RField.cxx.

◆ GetColumnRepresentative()

const ROOT::Experimental::RFieldBase::ColumnRepresentation_t & ROOT::Experimental::RFieldBase::GetColumnRepresentative ( ) const

Returns the fColumnRepresentative pointee or, if unset, the field's default representative.

Definition at line 916 of file RField.cxx.

◆ GetDeleter()

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

inlineprotectedvirtual

Definition at line 434 of file RField.hxx.

◆ GetDeleterOf()

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

inlinestaticprotected

Definition at line 437 of file RField.hxx.

◆ GetDescription()

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

inline

Get the field's description.

Definition at line 677 of file RField.hxx.

◆ GetFieldName()

std::string ROOT::Experimental::RFieldBase::GetFieldName ( ) const

inline

Definition at line 664 of file RField.hxx.

◆ GetFieldVersion()

virtual std::uint32_t ROOT::Experimental::RFieldBase::GetFieldVersion ( ) const

inlinevirtual

Indicates an evolution of the mapping scheme from C++ type to columns.

Definition at line 694 of file RField.hxx.

◆ GetNElements()

NTupleSize_t ROOT::Experimental::RFieldBase::GetNElements ( ) const

inline

Definition at line 671 of file RField.hxx.

◆ GetNRepetitions()

std::size_t ROOT::Experimental::RFieldBase::GetNRepetitions ( ) const

inline

Definition at line 670 of file RField.hxx.

◆ GetOnDiskId()

DescriptorId_t ROOT::Experimental::RFieldBase::GetOnDiskId ( ) const

inline

Definition at line 681 of file RField.hxx.

◆ GetOnDiskTypeVersion()

std::uint32_t ROOT::Experimental::RFieldBase::GetOnDiskTypeVersion ( ) const

inline

Return the C++ type version stored in the field descriptor; only valid after a call to ConnectPageSource()

Definition at line 698 of file RField.hxx.

◆ GetParent()

const RFieldBase * ROOT::Experimental::RFieldBase::GetParent ( ) const

inline

Definition at line 672 of file RField.hxx.

◆ GetPrincipalColumnOf()

static Internal::RColumn * ROOT::Experimental::RFieldBase::GetPrincipalColumnOf ( const RFieldBase & other )

inlinestaticprotected

Fields may need direct access to the principal column of their sub fields, e.g. in RRVecField::ReadBulk.

Definition at line 514 of file RField.hxx.

◆ GetQualifiedFieldName()

std::string ROOT::Experimental::RFieldBase::GetQualifiedFieldName ( ) const

Returns the field name and parent field names separated by dots ("grandparent.parent.child")

Definition at line 524 of file RField.cxx.

◆ GetState()

EState ROOT::Experimental::RFieldBase::GetState ( ) const

inline

Definition at line 679 of file RField.hxx.

◆ GetStructure()

ENTupleStructure ROOT::Experimental::RFieldBase::GetStructure ( ) const

inline

Definition at line 669 of file RField.hxx.

◆ GetSubFields() [1/2]

std::vector< ROOT::Experimental::RFieldBase * > ROOT::Experimental::RFieldBase::GetSubFields ( )

Definition at line 873 of file RField.cxx.

◆ GetSubFields() [2/2]

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

Definition at line 883 of file RField.cxx.

◆ GetTraits()

int ROOT::Experimental::RFieldBase::GetTraits ( ) const

inline

Definition at line 661 of file RField.hxx.

◆ GetTypeAlias()

std::string ROOT::Experimental::RFieldBase::GetTypeAlias ( ) const

inline

Definition at line 668 of file RField.hxx.

◆ GetTypeName()

std::string ROOT::Experimental::RFieldBase::GetTypeName ( ) const

inline

Definition at line 667 of file RField.hxx.

◆ GetTypeVersion()

virtual std::uint32_t ROOT::Experimental::RFieldBase::GetTypeVersion ( ) const

inlinevirtual

Indicates an evolution of the C++ type itself.

Reimplemented in ROOT::Experimental::RClassField.

Definition at line 696 of file RField.hxx.

◆ GetValueSize()

virtual size_t ROOT::Experimental::RFieldBase::GetValueSize ( ) const

pure virtual

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

◆ HasDefaultColumnRepresentative()

bool ROOT::Experimental::RFieldBase::HasDefaultColumnRepresentative ( ) const

inline

Whether or not an explicit column representative was set.

Definition at line 691 of file RField.hxx.

◆ HasReadCallbacks()

bool ROOT::Experimental::RFieldBase::HasReadCallbacks ( ) const

inline

Definition at line 662 of file RField.hxx.

◆ InvokeReadCallbacks()

void ROOT::Experimental::RFieldBase::InvokeReadCallbacks ( void * target )

inlineprivate

Definition at line 340 of file RField.hxx.

◆ IsSimple()

bool ROOT::Experimental::RFieldBase::IsSimple ( ) const

inline

Definition at line 675 of file RField.hxx.

◆ OnConnectPageSource()

virtual void ROOT::Experimental::RFieldBase::OnConnectPageSource ( )

inlineprotectedvirtual

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

Reimplemented in ROOT::Experimental::RClassField.

Definition at line 530 of file RField.hxx.

◆ operator=() [1/2]

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

delete

◆ operator=() [2/2]

RFieldBase & ROOT::Experimental::RFieldBase::operator= ( RFieldBase && )

default

◆ Read() [1/2]

void ROOT::Experimental::RFieldBase::Read	(	NTupleSize_t	globalIndex,
		void *	to
	)

inlineprotected

Populate a single value with data from the field.

The memory location pointed to by to needs to be of the fitting type. The fast path is conditioned by the field qualifying as simple, i.e. maps as-is to a single column and has no read callback.

Definition at line 462 of file RField.hxx.

◆ Read() [2/2]

void ROOT::Experimental::RFieldBase::Read	(	RClusterIndex	clusterIndex,
		void *	to
	)

inlineprotected

Definition at line 475 of file RField.hxx.

◆ ReadBulk()

std::size_t ROOT::Experimental::RFieldBase::ReadBulk ( const RBulkSpec & bulkSpec )

inlineprotected

Returns the number of newly available values, that is the number of bools in bulkSpec.fMaskAvail that flipped from false to true.

As a special return value, kAllSet can be used if all values are read independent from the masks.

Definition at line 496 of file RField.hxx.

◆ ReadBulkImpl()

std::size_t ROOT::Experimental::RFieldBase::ReadBulkImpl ( const RBulkSpec & bulkSpec )

protectedvirtual

General implementation of bulk read.

Loop over the required range and read values that are required and not already present. Derived classes may implement more optimized versions of this method. See ReadBulk() for the return value.

Reimplemented in ROOT::Experimental::RRVecField, and ROOT::Experimental::RField< RNTupleCardinality< SizeT > >.

Definition at line 810 of file RField.cxx.

◆ ReadGlobalImpl()

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

protectedvirtual

◆ ReadInClusterImpl()

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

inlineprotectedvirtual

Reimplemented in ROOT::Experimental::RClassField, ROOT::Experimental::REnumField, ROOT::Experimental::RRecordField, ROOT::Experimental::RArrayField, ROOT::Experimental::RArrayAsRVecField, ROOT::Experimental::RAtomicField, ROOT::Experimental::RField< RNTupleCardinality< SizeT > >, ROOT::Experimental::Internal::RArraySizeField, and ROOT::Experimental::Internal::RRDFCardinalityField.

Definition at line 443 of file RField.hxx.

◆ RemoveReadCallback()

void ROOT::Experimental::RFieldBase::RemoveReadCallback ( size_t idx )

protected

Definition at line 966 of file RField.cxx.

◆ SetColumnRepresentative()

void ROOT::Experimental::RFieldBase::SetColumnRepresentative ( const ColumnRepresentation_t & representative )

Fixes a column representative.

This can only be done before connecting the field to a page sink. Otherwise, or if the provided representation is not in the list of GetColumnRepresentations, an exception is thrown

Definition at line 923 of file RField.cxx.

◆ SetDescription()

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

Definition at line 901 of file RField.cxx.

◆ SetOnDiskId()

void ROOT::Experimental::RFieldBase::SetOnDiskId ( DescriptorId_t id )

Definition at line 908 of file RField.cxx.

◆ SplitValue()

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

virtual

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 in ROOT::Experimental::RArrayAsRVecField, ROOT::Experimental::RClassField, ROOT::Experimental::REnumField, ROOT::Experimental::RRecordField, ROOT::Experimental::RVectorField, ROOT::Experimental::RRVecField, ROOT::Experimental::RArrayField, ROOT::Experimental::RMapField, ROOT::Experimental::RUniquePtrField, ROOT::Experimental::RAtomicField, and ROOT::Experimental::RProxiedCollectionField.

Definition at line 845 of file RField.cxx.

Friends And Related Symbol Documentation

◆ Internal::CallCommitClusterOnField

void Internal::CallCommitClusterOnField ( RFieldBase & )

friend

◆ Internal::CallConnectPageSinkOnField

void Internal::CallConnectPageSinkOnField	(	RFieldBase &	,
		Internal::RPageSink &	,
		NTupleSize_t
	)

friend

◆ Internal::CallConnectPageSourceOnField

void Internal::CallConnectPageSourceOnField	(	RFieldBase &	,
		Internal::RPageSource &
	)

friend

◆ ROOT::Experimental::Internal::RFieldCallbackInjector

friend struct ROOT::Experimental::Internal::RFieldCallbackInjector

friend

Definition at line 96 of file RField.hxx.

◆ ROOT::Experimental::RCollectionField

friend class ROOT::Experimental::RCollectionField

friend

Definition at line 95 of file RField.hxx.

Member Data Documentation

◆ fColumnRepresentative

const ColumnRepresentation_t* ROOT::Experimental::RFieldBase::fColumnRepresentative = nullptr

protected

Points into the static vector GetColumnRepresentations().GetSerializationTypes() when SetColumnRepresentative is called.

Otherwise GetColumnRepresentative returns the default representation.

Definition at line 410 of file RField.hxx.

◆ fColumns

std::vector<std::unique_ptr<Internal::RColumn> > ROOT::Experimental::RFieldBase::fColumns

protected

The columns are connected either to a sink or to a source (not to both); they are owned by the field.

Definition at line 399 of file RField.hxx.

◆ fDescription

std::string ROOT::Experimental::RFieldBase::fDescription

private

Free text set by the user.

Definition at line 336 of file RField.hxx.

◆ fIsSimple

bool ROOT::Experimental::RFieldBase::fIsSimple

private

A field qualifies as simple if it is both mappable and has no post-read callback.

Definition at line 330 of file RField.hxx.

◆ fName

std::string ROOT::Experimental::RFieldBase::fName

private

The field name relative to its parent field.

Definition at line 322 of file RField.hxx.

◆ fNRepetitions

std::size_t ROOT::Experimental::RFieldBase::fNRepetitions

private

For fixed sized arrays, the array length.

Definition at line 328 of file RField.hxx.

◆ fOnDiskId

DescriptorId_t ROOT::Experimental::RFieldBase::fOnDiskId = kInvalidDescriptorId

private

When the columns are connected to a page source or page sink, the field represents a field id in the corresponding RNTuple descriptor.

This on-disk ID is set in RPageSink::Create() for writing and by RFieldDescriptor::CreateField() when recreating a field / model from the stored descriptor.

Definition at line 334 of file RField.hxx.

◆ fOnDiskTypeVersion

std::uint32_t ROOT::Experimental::RFieldBase::fOnDiskTypeVersion = kInvalidTypeVersion

protected

C++ type version cached from the descriptor after a call to ConnectPageSource()

Definition at line 407 of file RField.hxx.

◆ fParent

RFieldBase* ROOT::Experimental::RFieldBase::fParent

protected

Sub fields point to their mother field.

Definition at line 393 of file RField.hxx.

◆ fPrincipalColumn

Internal::RColumn* ROOT::Experimental::RFieldBase::fPrincipalColumn

protected

Points into fColumns.

All fields that have columns have a distinct main column. For simple fields (float, int, ...), the principal column corresponds to the field type. For collection fields expect std::array, the main column is the offset field. Class fields have no column of their own.

Definition at line 397 of file RField.hxx.

◆ fReadCallbacks

std::vector<ReadCallback_t> ROOT::Experimental::RFieldBase::fReadCallbacks

protected

List of functions to be called after reading a value.

Definition at line 405 of file RField.hxx.

◆ fState

EState ROOT::Experimental::RFieldBase::fState = EState::kUnconnected

private

Changed by ConnectTo[Sink,Source], reset by Clone()

Definition at line 338 of file RField.hxx.

◆ fStructure

ENTupleStructure ROOT::Experimental::RFieldBase::fStructure

private

The role of this field in the data model structure.

Definition at line 326 of file RField.hxx.

◆ fSubFields

std::vector<std::unique_ptr<RFieldBase> > ROOT::Experimental::RFieldBase::fSubFields

protected

Collections and classes own sub fields.

Definition at line 391 of file RField.hxx.

◆ fTraits

int ROOT::Experimental::RFieldBase::fTraits = 0

protected

Properties of the type that allow for optimizations of collections of that type.

Definition at line 401 of file RField.hxx.

◆ fType

std::string ROOT::Experimental::RFieldBase::fType

private

The C++ type captured by this field.

Definition at line 324 of file RField.hxx.

◆ fTypeAlias

std::string ROOT::Experimental::RFieldBase::fTypeAlias

protected

A typedef or using name that was used when creating the field.

Definition at line 403 of file RField.hxx.

◆ kInvalidTypeVersion

constexpr std::uint32_t ROOT::Experimental::RFieldBase::kInvalidTypeVersion = -1U

staticconstexpr

Definition at line 137 of file RField.hxx.

◆ kTraitMappable

constexpr int ROOT::Experimental::RFieldBase::kTraitMappable = 0x04

staticconstexpr

A field of a fundamental type that can be directly mapped via RField<T>::Map(), i.e.

maps as-is to a single column

Definition at line 145 of file RField.hxx.

◆ kTraitTriviallyConstructible

constexpr int ROOT::Experimental::RFieldBase::kTraitTriviallyConstructible = 0x01

staticconstexpr

No constructor needs to be called, i.e.

any bit pattern in the allocated memory represents a valid type A trivially constructible field has a no-op ConstructValue() implementation

Definition at line 140 of file RField.hxx.

◆ kTraitTriviallyDestructible

constexpr int ROOT::Experimental::RFieldBase::kTraitTriviallyDestructible = 0x02

staticconstexpr

The type is cleaned up just by freeing its memory. I.e. the destructor performs a no-op.

Definition at line 142 of file RField.hxx.

◆ kTraitTrivialType

constexpr int ROOT::Experimental::RFieldBase::kTraitTrivialType = kTraitTriviallyConstructible | kTraitTriviallyDestructible

staticconstexpr

Shorthand for types that are both trivially constructible and destructible.

Definition at line 147 of file RField.hxx.

Libraries for ROOT::Experimental::RFieldBase:

[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

Classes

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Private Types

Private Member Functions

Private Attributes

Friends

Member Typedef Documentation

◆ ColumnRepresentation_t

◆ RConstSchemaIterator

◆ ReadCallback_t

◆ RSchemaIterator

Member Enumeration Documentation

◆ EState

| |

Constructor & Destructor Documentation

◆ RFieldBase() [1/3]

◆ RFieldBase() [2/3]

◆ RFieldBase() [3/3]

◆ ~RFieldBase()

Member Function Documentation

◆ AcceptVisitor()

◆ AddReadCallback()

◆ Append()

◆ AppendImpl()

◆ Attach()

◆ AutoAdjustColumnTypes()

◆ begin()

◆ BindValue()

◆ CallAppendOn()

◆ CallConstructValueOn()

◆ CallReadOn() [1/2]

◆ CallReadOn() [2/2]

◆ cbegin()

◆ cend()

◆ Check()

◆ Clone()

◆ CloneImpl()

◆ CommitCluster()

◆ CommitClusterImpl()

◆ ConnectPageSink()

◆ ConnectPageSource()

◆ ConstructValue()

◆ Create() [1/2]

◆ Create() [2/2]

◆ CreateBulk()

◆ CreateObject() [1/3]

◆ CreateObject() [2/3]

◆ CreateObject() [3/3]

◆ CreateObjectRawPtr()

◆ CreateValue()

◆ end()

◆ EnsureCompatibleColumnTypes()

◆ EnsureValidFieldName()

◆ EntryToColumnElementIndex()

◆ GenerateColumnsImpl() [1/2]

◆ GenerateColumnsImpl() [2/2]

◆ GetAlignment()

◆ GetColumnRepresentations()

◆ GetColumnRepresentative()

◆ GetDeleter()

◆ GetDeleterOf()

◆ GetDescription()

◆ GetFieldName()

◆ GetFieldVersion()

◆ GetNElements()

◆ GetNRepetitions()

◆ GetOnDiskId()

◆ GetOnDiskTypeVersion()

◆ GetParent()

◆ GetPrincipalColumnOf()

◆ GetQualifiedFieldName()

◆ GetState()

◆ GetStructure()

◆ GetSubFields() [1/2]