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ROOT::Experimental::RFieldZero Class Reference

The container field for an ntuple model, which itself has no physical representation.

Therefore, the zero field must not be connected to a page source or sink.

Definition at line 655 of file RField.hxx.

Public Member Functions

 RFieldZero ()
 
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.
 
size_t GetValueSize () const final
 The number of bytes taken by a value of the appropriate type.
 
- Public Member Functions inherited from ROOT::Experimental::Detail::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 ()
 
RSchemaIterator begin ()
 
RValue BindValue (void *where)
 Creates a value from a memory location with an already constructed object.
 
RConstSchemaIterator cbegin () const
 
RConstSchemaIterator cend () const
 
std::unique_ptr< RFieldBaseClone (std::string_view newName) const
 Copies the field and its sub fields using a possibly new name and a new, unconnected set of columns.
 
void CommitCluster ()
 Flushes data from active columns to disk and calls CommitClusterImpl.
 
void ConnectPageSink (RPageSink &pageSink, NTupleSize_t firstEntry=0)
 Fields and their columns live in the void until connected to a physical page storage.
 
void ConnectPageSource (RPageSource &pageSource)
 
RSchemaIterator end ()
 
RBulk GenerateBulk ()
 The returned bulk is initially empty; RBulk::ReadBulk will construct the array of values.
 
RValue GenerateValue ()
 Generates an object of the field type and allocates new initialized memory according to the type.
 
const ColumnRepresentation_tGetColumnRepresentative () const
 Returns the fColumnRepresentative pointee or, if unset, the field's default representative.
 
std::string GetDescription () const
 Get the field's description.
 
virtual std::uint32_t GetFieldVersion () const
 Indicates an evolution of the mapping scheme from C++ type to columns.
 
std::string GetName () const
 
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()
 
RFieldBaseGetParent () 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 () const
 
int GetTraits () const
 
std::string GetType () const
 
std::string GetTypeAlias () 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
 
RFieldBaseoperator= (const RFieldBase &)=delete
 
RFieldBaseoperator= (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< RValueSplitValue (const RValue &value) const
 Creates the list of direct child values given a value for this field.
 

Protected Member Functions

std::unique_ptr< Detail::RFieldBaseCloneImpl (std::string_view newName) const override
 Called by Clone(), which additionally copies the on-disk ID.
 
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.
 
void GenerateValue (void *) const final
 Constructs value in a given location of size at least GetValueSize(). Called by the base class' GenerateValue().
 
- Protected Member Functions inherited from ROOT::Experimental::Detail::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< Detail::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 ()
 
virtual void DestroyValue (void *objPtr, bool dtorOnly=false) const
 Releases the resources acquired during GenerateValue (memory and constructor) This implementation works for types with a trivial destructor and should be overwritten otherwise.
 
const ColumnRepresentation_tEnsureCompatibleColumnTypes (const RNTupleDescriptor &desc) const
 Returns the on-disk column types found in the provided descriptor for fOnDiskId.
 
virtual const RColumnRepresentationsGetColumnRepresentations () 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 (const RClusterIndex &clusterIndex, void *to)
 
void Read (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.
 
virtual void ReadGlobalImpl (NTupleSize_t globalIndex, void *to)
 
virtual void ReadInClusterImpl (const RClusterIndex &clusterIndex, void *to)
 
void RemoveReadCallback (size_t idx)
 

Additional Inherited Members

- Public Types inherited from ROOT::Experimental::Detail::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::Detail::RFieldBase
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::Detail::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. DestroyValue() is 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::Detail::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 CallDestroyValueOn (const RFieldBase &other, void *objPtr, bool dtorOnly=false)
 
static void CallGenerateValueOn (const RFieldBase &other, void *where)
 Allow derived classes to call GenerateValue(void *) and DestroyValue on other (sub) fields.
 
static void CallReadOn (RFieldBase &other, const RClusterIndex &clusterIndex, void *to)
 
static void CallReadOn (RFieldBase &other, NTupleSize_t globalIndex, void *to)
 
static RResult< std::unique_ptr< RFieldBase > > Create (const std::string &fieldName, const std::string &canonicalType, const std::string &typeAlias)
 Factory method to resurrect a field from the stored on-disk type information.
 
static RColumnGetPrincipalColumnOf (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::Detail::RFieldBase
const ColumnRepresentation_tfColumnRepresentative = nullptr
 Points into the static vector GetColumnRepresentations().GetSerializationTypes() when SetColumnRepresentative is called.
 
std::vector< std::unique_ptr< 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()
 
RFieldBasefParent
 Sub fields point to their mother field.
 
RColumnfPrincipalColumn
 Points into fColumns.
 
std::vector< ReadCallback_tfReadCallbacks
 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::RFieldZero:
[legend]

Constructor & Destructor Documentation

◆ RFieldZero()

ROOT::Experimental::RFieldZero::RFieldZero ( )
inline

Definition at line 663 of file RField.hxx.

Member Function Documentation

◆ AcceptVisitor()

void ROOT::Experimental::RFieldZero::AcceptVisitor ( Detail::RFieldVisitor visitor) const
finalvirtual

Reimplemented from ROOT::Experimental::Detail::RFieldBase.

Definition at line 797 of file RField.cxx.

◆ CloneImpl()

std::unique_ptr< ROOT::Experimental::Detail::RFieldBase > ROOT::Experimental::RFieldZero::CloneImpl ( std::string_view  newName) const
overrideprotectedvirtual

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

Implements ROOT::Experimental::Detail::RFieldBase.

Definition at line 788 of file RField.cxx.

◆ GenerateColumnsImpl() [1/2]

void ROOT::Experimental::RFieldZero::GenerateColumnsImpl ( )
inlinefinalprotectedvirtual

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

Implements ROOT::Experimental::Detail::RFieldBase.

Definition at line 658 of file RField.hxx.

◆ GenerateColumnsImpl() [2/2]

void ROOT::Experimental::RFieldZero::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::Detail::RFieldBase.

Definition at line 659 of file RField.hxx.

◆ GenerateValue()

void ROOT::Experimental::RFieldZero::GenerateValue ( void *  where) const
inlinefinalprotectedvirtual

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

Implements ROOT::Experimental::Detail::RFieldBase.

Definition at line 660 of file RField.hxx.

◆ GetAlignment()

size_t ROOT::Experimental::RFieldZero::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::Detail::RFieldBase.

Definition at line 668 of file RField.hxx.

◆ GetValueSize()

size_t ROOT::Experimental::RFieldZero::GetValueSize ( ) const
inlinefinalvirtual

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

Implements ROOT::Experimental::Detail::RFieldBase.

Definition at line 667 of file RField.hxx.

Libraries for ROOT::Experimental::RFieldZero:

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