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Reference Guide
ROOT::Experimental::Internal::RRDFCardinalityField Class Reference

An artificial field that transforms an RNTuple column that contains the offset of collections into collection sizes.

It is used to provide the "number of" RDF columns for collections, e.g. R_rdf_sizeof_jets for a collection named jets.

This field owns the collection offset field but instead of exposing the collection offsets it exposes the collection sizes (offset(N+1) - offset(N)). For the time being, we offer this functionality only in RDataFrame. TODO(jblomer): consider providing a general set of useful virtual fields as part of RNTuple.

Definition at line 44 of file RNTupleDS.cxx.

Public Member Functions

 RRDFCardinalityField ()
 
 RRDFCardinalityField (RRDFCardinalityField &&other)=default
 
 ~RRDFCardinalityField ()=default
 
ROOT::Experimental::Detail::RFieldValue CaptureValue (void *where) final
 Creates a value from a memory location with an already constructed object. More...
 
void GenerateColumnsImpl () final
 Creates the backing columns corresponsing to the field type for writing. More...
 
void GenerateColumnsImpl (const RNTupleDescriptor &) final
 Creates the backing columns corresponsing to the field type for reading. More...
 
ROOT::Experimental::Detail::RFieldValue GenerateValue (void *where) final
 Generates a tree value in a given location of size at least GetValueSize(). More...
 
size_t GetValueSize () const final
 The number of bytes taken by a value of the appropriate type. More...
 
RRDFCardinalityFieldoperator= (RRDFCardinalityField &&other)=default
 
void ReadGlobalImpl (ROOT::Experimental::NTupleSize_t globalIndex, ROOT::Experimental::Detail::RFieldValue *value) final
 Get the number of elements of the collection identified by globalIndex. More...
 
void ReadInClusterImpl (const ROOT::Experimental::RClusterIndex &clusterIndex, ROOT::Experimental::Detail::RFieldValue *value) final
 Get the number of elements of the collection identified by clusterIndex. More...
 
- 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. More...
 
virtual ~RFieldBase ()
 
virtual void AcceptVisitor (RFieldVisitor &visitor) const
 
std::size_t Append (const RFieldValue &value)
 Write the given value into columns. More...
 
void Attach (std::unique_ptr< Detail::RFieldBase > child)
 Add a new subfield to the list of nested fields. More...
 
RSchemaIterator begin ()
 
virtual RFieldValue CaptureValue (void *where)=0
 Creates a value from a memory location with an already constructed object. More...
 
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. More...
 
virtual void CommitCluster ()
 Perform housekeeping tasks for global to cluster-local index translation. More...
 
void ConnectPageSink (RPageSink &pageSink)
 Fields and their columns live in the void until connected to a physical page storage. More...
 
void ConnectPageSource (RPageSource &pageSource)
 
virtual void DestroyValue (const RFieldValue &value, bool dtorOnly=false)
 Releases the resources acquired during GenerateValue (memory and constructor) This implementation works for simple types but needs to be overwritten for complex ones. More...
 
RSchemaIterator end ()
 
void Flush () const
 Ensure that all received items are written from page buffers to the storage. More...
 
RFieldValue GenerateValue ()
 Generates an object of the field type and allocates new initialized memory according to the type. More...
 
virtual RFieldValue GenerateValue (void *where)=0
 Generates a tree value in a given location of size at least GetValueSize(). More...
 
virtual size_t GetAlignment () const
 For many types, the alignment requirement is equal to the size; otherwise override. More...
 
std::string GetDescription () const
 Get the field's description. More...
 
virtual RNTupleVersion GetFieldVersion () const
 Indicates an evolution of the mapping scheme from C++ type to columns. More...
 
std::string GetName () const
 
NTupleSize_t GetNElements () const
 
std::size_t GetNRepetitions () const
 
DescriptorId_t GetOnDiskId () const
 
RFieldBaseGetParent () const
 
ENTupleStructure GetStructure () const
 
std::vector< RFieldBase * > GetSubFields () const
 
std::string GetType () const
 
virtual RNTupleVersion GetTypeVersion () const
 Indicates an evolution of the C++ type itself. More...
 
virtual size_t GetValueSize () const =0
 The number of bytes taken by a value of the appropriate type. More...
 
bool IsSimple () const
 
RFieldBaseoperator= (const RFieldBase &)=delete
 
RFieldBaseoperator= (RFieldBase &&)=default
 
void Read (const RClusterIndex &clusterIndex, RFieldValue *value)
 
void Read (NTupleSize_t globalIndex, RFieldValue *value)
 Populate a single value with data from the tree, which needs to be of the fitting type. More...
 
void SetDescription (std::string_view description)
 
void SetOnDiskId (DescriptorId_t id)
 
virtual std::vector< RFieldValueSplitValue (const RFieldValue &value) const
 Creates the list of direct child values given a value for this field. More...
 

Static Public Member Functions

static std::string TypeName ()
 
- 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. More...
 
static RResult< voidEnsureValidFieldName (std::string_view fieldName)
 Check whether a given string is a valid field name. More...
 

Protected Member Functions

std::unique_ptr< ROOT::Experimental::Detail::RFieldBaseCloneImpl (std::string_view) const final
 Called by Clone(), which additionally copies the on-disk ID. More...
 
- Protected Member Functions inherited from ROOT::Experimental::Detail::RFieldBase
virtual std::size_t AppendImpl (const RFieldValue &value)
 Operations on values of complex types, e.g. More...
 
virtual std::unique_ptr< RFieldBaseCloneImpl (std::string_view newName) const =0
 Called by Clone(), which additionally copies the on-disk ID. More...
 
ROOT::Experimental::EColumnType EnsureColumnType (const std::vector< EColumnType > &requestedTypes, unsigned int columnIndex, const RNTupleDescriptor &desc)
 Throws an exception if the column given by fOnDiskId and the columnIndex in the provided descriptor is not of one of the requested types. More...
 
virtual void GenerateColumnsImpl ()=0
 Creates the backing columns corresponsing to the field type for writing. More...
 
virtual void GenerateColumnsImpl (const RNTupleDescriptor &desc)=0
 Creates the backing columns corresponsing to the field type for reading. More...
 
virtual void ReadGlobalImpl (NTupleSize_t globalIndex, RFieldValue *value)
 
virtual void ReadInClusterImpl (const RClusterIndex &clusterIndex, RFieldValue *value)
 

Additional Inherited Members

- Protected Attributes inherited from ROOT::Experimental::Detail::RFieldBase
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. More...
 
RFieldBasefParent
 Sub fields point to their mother field. More...
 
RColumnfPrincipalColumn
 Points into fColumns. More...
 
std::vector< std::unique_ptr< RFieldBase > > fSubFields
 Collections and classes own sub fields. More...
 
Inheritance diagram for ROOT::Experimental::Internal::RRDFCardinalityField:
[legend]

Constructor & Destructor Documentation

◆ RRDFCardinalityField() [1/2]

ROOT::Experimental::Internal::RRDFCardinalityField::RRDFCardinalityField ( )
inline

Definition at line 53 of file RNTupleDS.cxx.

◆ RRDFCardinalityField() [2/2]

ROOT::Experimental::Internal::RRDFCardinalityField::RRDFCardinalityField ( RRDFCardinalityField &&  other)
default

◆ ~RRDFCardinalityField()

ROOT::Experimental::Internal::RRDFCardinalityField::~RRDFCardinalityField ( )
default

Member Function Documentation

◆ CaptureValue()

ROOT::Experimental::Detail::RFieldValue ROOT::Experimental::Internal::RRDFCardinalityField::CaptureValue ( void where)
inlinefinalvirtual

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

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

Definition at line 74 of file RNTupleDS.cxx.

◆ CloneImpl()

std::unique_ptr< ROOT::Experimental::Detail::RFieldBase > ROOT::Experimental::Internal::RRDFCardinalityField::CloneImpl ( std::string_view  newName) const
inlinefinalprotectedvirtual

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

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

Definition at line 46 of file RNTupleDS.cxx.

◆ GenerateColumnsImpl() [1/2]

void ROOT::Experimental::Internal::RRDFCardinalityField::GenerateColumnsImpl ( )
inlinefinalvirtual

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

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

Definition at line 60 of file RNTupleDS.cxx.

◆ GenerateColumnsImpl() [2/2]

void ROOT::Experimental::Internal::RRDFCardinalityField::GenerateColumnsImpl ( const RNTupleDescriptor desc)
inlinefinalvirtual

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 62 of file RNTupleDS.cxx.

◆ GenerateValue()

ROOT::Experimental::Detail::RFieldValue ROOT::Experimental::Internal::RRDFCardinalityField::GenerateValue ( void where)
inlinefinalvirtual

Generates a tree value in a given location of size at least GetValueSize().

Assumes that where has been allocated by malloc().

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

Definition at line 70 of file RNTupleDS.cxx.

◆ GetValueSize()

size_t ROOT::Experimental::Internal::RRDFCardinalityField::GetValueSize ( ) const
inlinefinalvirtual

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

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

Definition at line 78 of file RNTupleDS.cxx.

◆ operator=()

RRDFCardinalityField & ROOT::Experimental::Internal::RRDFCardinalityField::operator= ( RRDFCardinalityField &&  other)
default

◆ ReadGlobalImpl()

void ROOT::Experimental::Internal::RRDFCardinalityField::ReadGlobalImpl ( ROOT::Experimental::NTupleSize_t  globalIndex,
ROOT::Experimental::Detail::RFieldValue value 
)
inlinefinalvirtual

Get the number of elements of the collection identified by globalIndex.

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

Definition at line 82 of file RNTupleDS.cxx.

◆ ReadInClusterImpl()

void ROOT::Experimental::Internal::RRDFCardinalityField::ReadInClusterImpl ( const ROOT::Experimental::RClusterIndex clusterIndex,
ROOT::Experimental::Detail::RFieldValue value 
)
inlinefinalvirtual

Get the number of elements of the collection identified by clusterIndex.

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

Definition at line 91 of file RNTupleDS.cxx.

◆ TypeName()

static std::string ROOT::Experimental::Internal::RRDFCardinalityField::TypeName ( )
inlinestatic

Definition at line 52 of file RNTupleDS.cxx.


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