The field for a class with dictionary.

Definition at line 115 of file RField.hxx.

Classes
class	RClassDeleter

struct	RStagingItem

struct	RSubFieldInfo

Public Member Functions
	RClassField (RClassField &&other)=default

	RClassField (std::string_view fieldName, std::string_view className)

	~RClassField () override=default

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

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

std::uint32_t	GetTypeChecksum () const final
	Return the current TClass reported checksum of this class. Only valid if kTraitTypeChecksum is set.

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

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

RClassField &	operator= (RClassField &&other)=default

std::vector< RValue >	SplitValue (const 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, ROOT::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 ()

RConstSchemaIterator	begin () const

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

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 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 ()

RConstSchemaIterator	end () const

RColumnRepresentations::Selection_t	GetColumnRepresentatives () const
	Returns the fColumnRepresentative pointee or, if unset (always the case for artificial fields), the field's default representative.

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

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

const std::string &	GetFieldName () const

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

std::vector< RFieldBase * >	GetMutableSubfields ()

std::size_t	GetNRepetitions () const

ROOT::DescriptorId_t	GetOnDiskId () const

std::uint32_t	GetOnDiskTypeChecksum () const
	Return checksum stored in the field descriptor; only valid after a call to `ConnectPageSource()`, if the field stored a type checksum.

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

ROOT::ENTupleStructure	GetStructure () const

std::uint32_t	GetTraits () const

const std::string &	GetTypeAlias () const

const std::string &	GetTypeName () const

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

bool	HasReadCallbacks () const

bool	IsArtificial () const

bool	IsSimple () const

RFieldBase &	operator= (const RFieldBase &)=delete

RFieldBase &	operator= (RFieldBase &&)=default

void	SetColumnRepresentatives (const RColumnRepresentations::Selection_t &representatives)
	Fixes a column representative.

void	SetDescription (std::string_view description)

void	SetOnDiskId (ROOT::DescriptorId_t id)

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

void	BeforeConnectPageSource (Internal::RPageSource &pageSource) final
	Called by `ConnectPageSource()` before connecting; derived classes may override this as appropriate.

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

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

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

void	ReadGlobalImpl (ROOT::NTupleSize_t globalIndex, void *to) final

void	ReadInClusterImpl (RNTupleLocalIndex localIndex, 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.

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

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

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

void	AutoAdjustColumnTypes (const ROOT::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 ()

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

const ColumnRepresentation_t &	EnsureCompatibleColumnTypes (const RNTupleDescriptor &desc, std::uint16_t representationIndex) const
	Returns the on-disk column types found in the provided descriptor for fOnDiskId and the given representation index.

virtual void	GenerateColumns ()
	Implementations in derived classes should create the backing columns corresponsing to the field type for writing.

virtual void	GenerateColumns (const RNTupleDescriptor &)
	Implementations in derived classes should create the backing columns corresponsing to the field type for reading.

template<typename... ColumnCppTs>
void	GenerateColumnsImpl ()
	For writing, use the currently set column representative.

template<std::uint32_t ColumnIndexT, typename HeadT , typename... TailTs>
void	GenerateColumnsImpl (const ColumnRepresentation_t &representation, std::uint16_t representationIndex)
	Helpers for generating columns.

template<typename... ColumnCppTs>
void	GenerateColumnsImpl (const RNTupleDescriptor &desc)
	For reading, use the on-disk column list.

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

virtual RExtraTypeInfoDescriptor	GetExtraTypeInfo () const

virtual bool	HasExtraTypeInfo () const

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

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

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 Types
enum	ESubFieldRole { kBaseClass , kDataMember }

Private Member Functions
	RClassField (std::string_view fieldName, const RClassField &source)
	Used by CloneImpl.

	RClassField (std::string_view fieldName, TClass *classp)

void	AddReadCallbacksFromIORule (const TSchemaRule *rule)
	Register post-read callback corresponding to a ROOT I/O customization rules.

void	Attach (std::unique_ptr< RFieldBase > child, RSubFieldInfo info)

std::vector< const TSchemaRule * >	FindRules (const RFieldDescriptor *fieldDesc)
	Given the on-disk information from the page source, find all the I/O customization rules that apply to the class field at hand, to which the fieldDesc descriptor, if provided, must correspond.

ROOT::DescriptorId_t	LookupMember (const RNTupleDescriptor &desc, std::string_view memberName, ROOT::DescriptorId_t classFieldId)
	Returns the id of member 'name' in the class field given by 'fieldId', or kInvalidDescriptorId if no such member exist.

void	PrepareStagingArea (const std::vector< const TSchemaRule * > &rules, const RNTupleDescriptor &desc, const RFieldDescriptor &classFieldId)
	If there are rules with inputs (source members), create the staging area according to the TClass instance that corresponds to the on-disk field.

void	SetStagingClass (const std::string &className, unsigned int classVersion)
	Sets fStagingClass according to the given name and version.

Private Attributes
TClass *	fClass

std::size_t	fMaxAlignment = 1

std::unique_ptr< unsigned char[]>	fStagingArea
	The staging area stores inputs to I/O rules according to the offsets given by the streamer info of "TypeName@@Version".

TClass *	fStagingClass = nullptr
	The TClass instance that corresponds to the staging area.

std::unordered_map< std::string, RStagingItem >	fStagingItems
	Lookup staging items by member name.

std::vector< RSubFieldInfo >	fSubfieldsInfo
	Additional information kept for each entry in `fSubfields`

Static Private Attributes
static constexpr const char *	kPrefixInherited {":"}
	Prefix used in the subfield names generated for base classes.

Additional Inherited Members
Public Types inherited from ROOT::Experimental::RFieldBase
enum	{ kTraitTriviallyConstructible = 0x01 , kTraitTriviallyDestructible = 0x02 , kTraitMappable = 0x04 , kTraitTypeChecksum = 0x08 , kTraitInvalidField = 0x10 , kTraitEmulatedField = 0x20 , kTraitTrivialType = kTraitTriviallyConstructible \| kTraitTriviallyDestructible }

using	ColumnRepresentation_t = std::vector<ROOT::ENTupleColumnType>

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 create a field from a certain type given as string.

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

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 *	CallCreateObjectRawPtrOn (RFieldBase &other)

static void	CallReadOn (RFieldBase &other, RNTupleLocalIndex localIndex, void *to)

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

static RResult< std::unique_ptr< RFieldBase > >	Create (const std::string &fieldName, const std::string &typeName, const ROOT::RCreateFieldOptions &options, const RNTupleDescriptor *desc, ROOT::DescriptorId_t fieldId)
	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
Internal::RColumn *	fAuxiliaryColumn = nullptr
	Some fields have a second column in its column representation.

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

std::vector< std::reference_wrapper< const ColumnRepresentation_t > >	fColumnRepresentatives
	Pointers into the static vector GetColumnRepresentations().GetSerializationTypes() when SetColumnRepresentatives is called.

std::uint32_t	fOnDiskTypeChecksum = 0
	TClass checksum cached from the descriptor after a call to `ConnectPageSource()`.

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 = nullptr
	All fields that have columns have a distinct main column.

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.

std::uint32_t	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::RClassField:

[legend]

Member Enumeration Documentation

◆ ESubFieldRole

enum ROOT::Experimental::RClassField::ESubFieldRole

private

Enumerator
kBaseClass
kDataMember

Definition at line 117 of file RField.hxx.

Constructor & Destructor Documentation

◆ RClassField() [1/4]

ROOT::Experimental::RClassField::RClassField	(	std::string_view	fieldName,
		const RClassField &	source )

private

Used by CloneImpl.

Definition at line 75 of file RFieldMeta.cxx.

◆ RClassField() [2/4]

ROOT::Experimental::RClassField::RClassField	(	std::string_view	fieldName,
		TClass *	classp )

private

Definition at line 93 of file RFieldMeta.cxx.

◆ RClassField() [3/4]

ROOT::Experimental::RClassField::RClassField	(	std::string_view	fieldName,
		std::string_view	className )

Definition at line 88 of file RFieldMeta.cxx.

◆ RClassField() [4/4]

ROOT::Experimental::RClassField::RClassField ( RClassField && other )

default

◆ ~RClassField()

ROOT::Experimental::RClassField::~RClassField ( )

overridedefault

Member Function Documentation

◆ AcceptVisitor()

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

finalvirtual

Reimplemented from ROOT::Experimental::RFieldBase.

Definition at line 482 of file RFieldMeta.cxx.

◆ AddReadCallbacksFromIORule()

void ROOT::Experimental::RClassField::AddReadCallbacksFromIORule ( const TSchemaRule * rule )

private

Register post-read callback corresponding to a ROOT I/O customization rules.

Definition at line 382 of file RFieldMeta.cxx.

◆ AppendImpl()

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

finalprotectedvirtual

Operations on values of complex types, e.g.

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

Reimplemented from ROOT::Experimental::RFieldBase.

Definition at line 283 of file RFieldMeta.cxx.

◆ Attach()

void ROOT::Experimental::RClassField::Attach	(	std::unique_ptr< RFieldBase >	child,
		RSubFieldInfo	info )

private

Definition at line 186 of file RFieldMeta.cxx.

◆ BeforeConnectPageSource()

void ROOT::Experimental::RClassField::BeforeConnectPageSource ( Internal::RPageSource & )

finalprotectedvirtual

Called by ConnectPageSource() before connecting; derived classes may override this as appropriate.

Reimplemented from ROOT::Experimental::RFieldBase.

Definition at line 395 of file RFieldMeta.cxx.

◆ CloneImpl()

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

finalprotectedvirtual

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

Implements ROOT::Experimental::RFieldBase.

Definition at line 278 of file RFieldMeta.cxx.

◆ ConstructValue()

void ROOT::Experimental::RClassField::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 443 of file RFieldMeta.cxx.

◆ FindRules()

std::vector< const ROOT::TSchemaRule * > ROOT::Experimental::RClassField::FindRules ( const RFieldDescriptor * fieldDesc )

private

Given the on-disk information from the page source, find all the I/O customization rules that apply to the class field at hand, to which the fieldDesc descriptor, if provided, must correspond.

Fields may not have an on-disk representation (e.g., when inserted by schema evolution), in which case the passed field descriptor is nullptr.

Definition at line 193 of file RFieldMeta.cxx.

◆ GetAlignment()

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

inlinefinalvirtual

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 201 of file RField.hxx.

◆ GetDeleter()

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

inlinefinalprotectedvirtual

Reimplemented from ROOT::Experimental::RFieldBase.

Definition at line 186 of file RField.hxx.

◆ GetTypeChecksum()

std::uint32_t ROOT::Experimental::RClassField::GetTypeChecksum ( ) const

finalvirtual

Return the current TClass reported checksum of this class. Only valid if kTraitTypeChecksum is set.

Reimplemented from ROOT::Experimental::RFieldBase.

Definition at line 477 of file RFieldMeta.cxx.

◆ GetTypeVersion()

std::uint32_t ROOT::Experimental::RClassField::GetTypeVersion ( ) const

finalvirtual

Indicates an evolution of the C++ type itself.

Reimplemented from ROOT::Experimental::RFieldBase.

Definition at line 472 of file RFieldMeta.cxx.

◆ GetValueSize()

size_t ROOT::Experimental::RClassField::GetValueSize ( ) const

finalvirtual

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

Implements ROOT::Experimental::RFieldBase.

Definition at line 467 of file RFieldMeta.cxx.

◆ LookupMember()

ROOT::DescriptorId_t ROOT::Experimental::RClassField::LookupMember	(	const RNTupleDescriptor &	desc,
		std::string_view	memberName,
		ROOT::DescriptorId_t	classFieldId )

private

Returns the id of member 'name' in the class field given by 'fieldId', or kInvalidDescriptorId if no such member exist.

Looks recursively in base classes.

Definition at line 312 of file RFieldMeta.cxx.

◆ operator=()

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

default

◆ PrepareStagingArea()

void ROOT::Experimental::RClassField::PrepareStagingArea	(	const std::vector< const TSchemaRule * > &	rules,
		const RNTupleDescriptor &	desc,
		const RFieldDescriptor &	classFieldId )

private

If there are rules with inputs (source members), create the staging area according to the TClass instance that corresponds to the on-disk field.

Definition at line 343 of file RFieldMeta.cxx.

◆ ReadGlobalImpl()

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

finalprotectedvirtual

Reimplemented from ROOT::Experimental::RFieldBase.

Definition at line 292 of file RFieldMeta.cxx.

◆ ReadInClusterImpl()

void ROOT::Experimental::RClassField::ReadInClusterImpl	(	RNTupleLocalIndex	localIndex,
		void *	to )

finalprotectedvirtual

Reimplemented from ROOT::Experimental::RFieldBase.

Definition at line 302 of file RFieldMeta.cxx.

◆ SetStagingClass()

void ROOT::Experimental::RClassField::SetStagingClass	(	const std::string &	className,
		unsigned int	classVersion )

private

Sets fStagingClass according to the given name and version.

Definition at line 332 of file RFieldMeta.cxx.

◆ SplitValue()

std::vector< ROOT::Experimental::RFieldBase::RValue > ROOT::Experimental::RClassField::SplitValue ( const 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 455 of file RFieldMeta.cxx.

Member Data Documentation

◆ fClass

TClass* ROOT::Experimental::RClassField::fClass

private

Definition at line 144 of file RField.hxx.

◆ fMaxAlignment

std::size_t ROOT::Experimental::RClassField::fMaxAlignment = 1

private

Definition at line 147 of file RField.hxx.

◆ fStagingArea

std::unique_ptr<unsigned char[]> ROOT::Experimental::RClassField::fStagingArea

private

The staging area stores inputs to I/O rules according to the offsets given by the streamer info of "TypeName@@Version".

The area is allocated depending on I/O rules resp. the source members of the I/O rules.

Definition at line 151 of file RField.hxx.

◆ fStagingClass

TClass* ROOT::Experimental::RClassField::fStagingClass = nullptr

private

The TClass instance that corresponds to the staging area.

The staging class exists as <class name>@<on-disk version> if the on-disk version is different from the current in-memory version, or it can be accessed by the first @alloc streamer element of the current streamer info.

Definition at line 156 of file RField.hxx.

◆ fStagingItems

std::unordered_map<std::string, RStagingItem> ROOT::Experimental::RClassField::fStagingItems

private

Lookup staging items by member name.

Definition at line 157 of file RField.hxx.

◆ fSubfieldsInfo

std::vector<RSubFieldInfo> ROOT::Experimental::RClassField::fSubfieldsInfo

private

Additional information kept for each entry in fSubfields

Definition at line 146 of file RField.hxx.

◆ kPrefixInherited

constexpr const char* ROOT::Experimental::RClassField::kPrefixInherited {":"}

staticconstexprprivate

Prefix used in the subfield names generated for base classes.

Definition at line 133 of file RField.hxx.

Libraries for ROOT::Experimental::RClassField:

[legend]

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

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

Classes

Public Member Functions

Protected Member Functions

Private Types

Private Member Functions

Private Attributes

Static Private Attributes

Additional Inherited Members

Member Enumeration Documentation

◆ ESubFieldRole

Constructor & Destructor Documentation

◆ RClassField() [1/4]

◆ RClassField() [2/4]

◆ RClassField() [3/4]

◆ RClassField() [4/4]

◆ ~RClassField()

Member Function Documentation

◆ AcceptVisitor()

◆ AddReadCallbacksFromIORule()

◆ AppendImpl()

◆ Attach()

◆ BeforeConnectPageSource()

◆ CloneImpl()

◆ ConstructValue()

◆ FindRules()

◆ GetAlignment()

◆ GetDeleter()

◆ GetTypeChecksum()

◆ GetTypeVersion()

◆ GetValueSize()

◆ LookupMember()

◆ operator=()

◆ PrepareStagingArea()

◆ ReadGlobalImpl()

◆ ReadInClusterImpl()

◆ SetStagingClass()

◆ SplitValue()

Member Data Documentation

◆ fClass

◆ fMaxAlignment

◆ fStagingArea

◆ fStagingClass

◆ fStagingItems

◆ fSubfieldsInfo

◆ kPrefixInherited