Logo ROOT  
Reference Guide
 
Loading...
Searching...
No Matches
ROOT::Experimental::RNullableField Class Reference

The field for values that may or may not be present in an entry.

Parent class for unique pointer field and optional field. A nullable field cannot be instantiated itself but only its descendants. The RNullableField takes care of the on-disk representation. Child classes are responsible for the in-memory representation. The on-disk representation can be "dense" or "sparse". Dense nullable fields have a bitmask (true: item available, false: item missing) and serialize a default-constructed item for missing items. Sparse nullable fields use a (Split)Index[64|32] column to point to the available items. By default, items whose size is smaller or equal to 4 bytes (size of (Split)Index32 column element) are stored densely.

Definition at line 1445 of file RField.hxx.

Public Member Functions

 RNullableField (RNullableField &&other)=default
 
 ~RNullableField () override=default
 
void AcceptVisitor (Detail::RFieldVisitor &visitor) const final
 
bool IsDense () const
 
bool IsSparse () const
 
RNullableFieldoperator= (RNullableField &&other)=default
 
void SetDense ()
 
void SetSparse ()
 
- 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< 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.
 
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_tGetColumnRepresentative () 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 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 ()
 
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
 
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

 RNullableField (std::string_view fieldName, std::string_view typeName, std::unique_ptr< RFieldBase > itemField)
 
std::size_t AppendNull ()
 
std::size_t AppendValue (const void *from)
 
void CommitClusterImpl () final
 
void GenerateColumnsImpl () final
 Implementations in derived classes should create the backing columns corresponsing to the field type for writing.
 
void GenerateColumnsImpl (const RNTupleDescriptor &) final
 Implementations in derived classes should create the backing columns corresponsing to the field type for reading.
 
const RFieldBase::RColumnRepresentationsGetColumnRepresentations () const final
 Implementations in derived classes should return a static RColumnRepresentations object.
 
RClusterIndex GetItemIndex (NTupleSize_t globalIndex)
 Given the index of the nullable field, returns the corresponding global index of the subfield or, if it is null, returns kInvalidClusterIndex.
 
- 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 std::unique_ptr< RFieldBaseCloneImpl (std::string_view newName) const =0
 Called by Clone(), which additionally copies the on-disk ID.
 
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_tEnsureCompatibleColumnTypes (const RNTupleDescriptor &desc) const
 Returns the on-disk column types found in the provided descriptor for fOnDiskId.
 
virtual std::unique_ptr< RDeleterGetDeleter () 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)
 

Private Attributes

std::unique_ptr< RValuefDefaultItemValue
 For a dense nullable field, used to write a default-constructed item for missing ones.
 
ClusterSize_t fNWritten {0}
 For a sparse nullable field, the number of written non-null items in this cluster.
 

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< RCheckResultCheck (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< RDeleterGetDeleterOf (const RFieldBase &other)
 
static Internal::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::RFieldBase
const ColumnRepresentation_tfColumnRepresentative = 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()
 
RFieldBasefParent
 Sub fields point to their mother field.
 
Internal::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::RNullableField:
[legend]

Constructor & Destructor Documentation

◆ RNullableField() [1/2]

ROOT::Experimental::RNullableField::RNullableField ( std::string_view  fieldName,
std::string_view  typeName,
std::unique_ptr< RFieldBase itemField 
)
protected

Definition at line 3409 of file RField.cxx.

◆ RNullableField() [2/2]

ROOT::Experimental::RNullableField::RNullableField ( RNullableField &&  other)
default

◆ ~RNullableField()

ROOT::Experimental::RNullableField::~RNullableField ( )
overridedefault

Member Function Documentation

◆ AcceptVisitor()

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

Reimplemented from ROOT::Experimental::RFieldBase.

Definition at line 3490 of file RField.cxx.

◆ AppendNull()

std::size_t ROOT::Experimental::RNullableField::AppendNull ( )
protected

Definition at line 3450 of file RField.cxx.

◆ AppendValue()

std::size_t ROOT::Experimental::RNullableField::AppendValue ( const void *  from)
protected

Definition at line 3462 of file RField.cxx.

◆ CommitClusterImpl()

void ROOT::Experimental::RNullableField::CommitClusterImpl ( )
inlinefinalprotectedvirtual

Reimplemented from ROOT::Experimental::RFieldBase.

Definition at line 1458 of file RField.hxx.

◆ GenerateColumnsImpl() [1/2]

void ROOT::Experimental::RNullableField::GenerateColumnsImpl ( )
finalprotectedvirtual

Implementations in derived classes should create the backing columns corresponsing to the field type for writing.

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

Reimplemented from ROOT::Experimental::RFieldBase.

Definition at line 3425 of file RField.cxx.

◆ GenerateColumnsImpl() [2/2]

void ROOT::Experimental::RNullableField::GenerateColumnsImpl ( const RNTupleDescriptor )
finalprotectedvirtual

Implementations in derived classes should create the backing columns corresponsing to the field type for reading.

The default implementation does not attach any columns to the field. The method should check, using the page source and fOnDiskId, if the column types match and throw if they don't.

Reimplemented from ROOT::Experimental::RFieldBase.

Definition at line 3440 of file RField.cxx.

◆ GetColumnRepresentations()

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

Implementations in derived classes should return a static RColumnRepresentations object.

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

Reimplemented from ROOT::Experimental::RFieldBase.

Definition at line 3417 of file RField.cxx.

◆ GetItemIndex()

ROOT::Experimental::RClusterIndex ROOT::Experimental::RNullableField::GetItemIndex ( NTupleSize_t  globalIndex)
protected

Given the index of the nullable field, returns the corresponding global index of the subfield or, if it is null, returns kInvalidClusterIndex.

Definition at line 3476 of file RField.cxx.

◆ IsDense()

bool ROOT::Experimental::RNullableField::IsDense ( ) const
inline

Definition at line 1471 of file RField.hxx.

◆ IsSparse()

bool ROOT::Experimental::RNullableField::IsSparse ( ) const
inline

Definition at line 1472 of file RField.hxx.

◆ operator=()

RNullableField & ROOT::Experimental::RNullableField::operator= ( RNullableField &&  other)
default

◆ SetDense()

void ROOT::Experimental::RNullableField::SetDense ( )
inline

Definition at line 1473 of file RField.hxx.

◆ SetSparse()

void ROOT::Experimental::RNullableField::SetSparse ( )
inline

Definition at line 1474 of file RField.hxx.

Member Data Documentation

◆ fDefaultItemValue

std::unique_ptr<RValue> ROOT::Experimental::RNullableField::fDefaultItemValue
private

For a dense nullable field, used to write a default-constructed item for missing ones.

Definition at line 1447 of file RField.hxx.

◆ fNWritten

ClusterSize_t ROOT::Experimental::RNullableField::fNWritten {0}
private

For a sparse nullable field, the number of written non-null items in this cluster.

Definition at line 1449 of file RField.hxx.

Libraries for ROOT::Experimental::RNullableField:

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