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Reference Guide
ROOT::Experimental::RClassField Class Reference

The field for a class with dictionary.

Definition at line 352 of file RField.hxx.

Classes

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 override
 
Detail::RFieldValue CaptureValue (void *where) final
 Creates a value from a memory location with an already constructed object. More...
 
void DestroyValue (const Detail::RFieldValue &value, bool dtorOnly=false) final
 Releases the resources acquired during GenerateValue (memory and constructor) This implementation works for simple types but needs to be overwritten for complex ones. More...
 
void GenerateColumnsImpl () final
 Creates the backing columns corresponsing to the field type for writing. More...
 
void GenerateColumnsImpl (const RNTupleDescriptor &desc) final
 Creates the backing columns corresponsing to the field type for reading. More...
 
Detail::RFieldValue GenerateValue (void *where) override
 Generates a tree value in a given location of size at least GetValueSize(). More...
 
size_t GetAlignment () const final
 For many types, the alignment requirement is equal to the size; otherwise override. More...
 
std::uint32_t GetTypeVersion () const final
 Indicates an evolution of the C++ type itself. More...
 
size_t GetValueSize () const override
 The number of bytes taken by a value of the appropriate type. More...
 
RClassFieldoperator= (RClassField &&other)=default
 
std::vector< Detail::RFieldValueSplitValue (const Detail::RFieldValue &value) const final
 Creates the list of direct child values given a value for this field. 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 std::uint32_t 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
 
std::uint32_t GetOnDiskTypeVersion () const
 Return the C++ type version stored in the field descriptor; only valid after a call to ConnectPageSource() More...
 
RFieldBaseGetParent () const
 
std::string GetQualifiedFieldName () const
 Returns the field name and parent field names separated by dots ("grandparent.parent.child") More...
 
ENTupleStructure GetStructure () const
 
std::vector< RFieldBase * > GetSubFields () const
 
int GetTraits () const
 
std::string GetType () const
 
virtual std::uint32_t 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 HasReadCallbacks () const
 
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...
 

Protected Member Functions

std::size_t AppendImpl (const Detail::RFieldValue &value) final
 Operations on values of complex types, e.g. More...
 
std::unique_ptr< Detail::RFieldBaseCloneImpl (std::string_view newName) const final
 Called by Clone(), which additionally copies the on-disk ID. More...
 
void OnConnectPageSource () final
 Called by ConnectPageSource() only once connected; derived classes may override this as appropriate. More...
 
void ReadGlobalImpl (NTupleSize_t globalIndex, Detail::RFieldValue *value) final
 
void ReadInClusterImpl (const RClusterIndex &clusterIndex, Detail::RFieldValue *value) final
 
- 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. More...
 
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 OnConnectPageSource ()
 Called by ConnectPageSource() only once connected; derived classes may override this as appropriate. More...
 
virtual void ReadGlobalImpl (NTupleSize_t globalIndex, RFieldValue *value)
 
virtual void ReadInClusterImpl (const RClusterIndex &clusterIndex, RFieldValue *value)
 
void RemoveReadCallback (size_t idx)
 

Private Types

enum  ESubFieldRole { kBaseClass , kDataMember }
 

Private Member Functions

 RClassField (std::string_view fieldName, std::string_view className, TClass *classp)
 
void AddReadCallbacksFromIORules (const std::span< const TSchemaRule * > rules, TClass *classp=nullptr)
 Register post-read callbacks corresponding to a list of ROOT I/O customization rules. More...
 
void Attach (std::unique_ptr< Detail::RFieldBase > child, RSubFieldInfo info)
 

Private Attributes

TClassfClass
 
std::size_t fMaxAlignment = 1
 
std::vector< RSubFieldInfofSubFieldsInfo
 Additional information kept for each entry in fSubFields More...
 

Static Private Attributes

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

Additional Inherited Members

- 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< void > EnsureValidFieldName (std::string_view fieldName)
 Check whether a given string is a valid field name. More...
 
- 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. More...
 
static constexpr int kTraitTriviallyConstructible = 0x01
 No constructor needs to be called, i.e. More...
 
static constexpr int kTraitTriviallyDestructible = 0x02
 The type is cleaned up just by freeing its memory. I.e. DestroyValue() is a no-op. More...
 
static constexpr int kTraitTrivialType = kTraitTriviallyConstructible | kTraitTriviallyDestructible
 Shorthand for types that are both trivially constructible and destructible. More...
 
- 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...
 
std::uint32_t fOnDiskTypeVersion = kInvalidTypeVersion
 C++ type version cached from the descriptor after a call to ConnectPageSource() More...
 
RFieldBasefParent
 Sub fields point to their mother field. More...
 
RColumnfPrincipalColumn
 Points into fColumns. More...
 
std::vector< ReadCallback_tfReadCallbacks
 List of functions to be called after reading a value. More...
 
std::vector< std::unique_ptr< RFieldBase > > fSubFields
 Collections and classes own sub fields. More...
 
int fTraits = 0
 Properties of the type that allow for optimizations of collections of that type. More...
 

#include <ROOT/RField.hxx>

Inheritance diagram for ROOT::Experimental::RClassField:
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Member Enumeration Documentation

◆ ESubFieldRole

Enumerator
kBaseClass 
kDataMember 

Definition at line 354 of file RField.hxx.

Constructor & Destructor Documentation

◆ RClassField() [1/3]

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

Definition at line 885 of file RField.cxx.

◆ RClassField() [2/3]

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

Definition at line 880 of file RField.cxx.

◆ RClassField() [3/3]

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
overridevirtual

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

Definition at line 1072 of file RField.cxx.

◆ AddReadCallbacksFromIORules()

void ROOT::Experimental::RClassField::AddReadCallbacksFromIORules ( const std::span< const TSchemaRule * >  rules,
TClass classp = nullptr 
)
private

Register post-read callbacks corresponding to a list of ROOT I/O customization rules.

classp is used to fill the TVirtualObject instance passed to the user function.

Definition at line 947 of file RField.cxx.

◆ AppendImpl()

std::size_t ROOT::Experimental::RClassField::AppendImpl ( const Detail::RFieldValue value)
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::Detail::RFieldBase.

Definition at line 973 of file RField.cxx.

◆ Attach()

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

Definition at line 940 of file RField.cxx.

◆ CaptureValue()

ROOT::Experimental::Detail::RFieldValue ROOT::Experimental::RClassField::CaptureValue ( void *  where)
finalvirtual

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

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

Definition at line 1044 of file RField.cxx.

◆ CloneImpl()

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

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

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

Definition at line 968 of file RField.cxx.

◆ DestroyValue()

void ROOT::Experimental::RClassField::DestroyValue ( const Detail::RFieldValue value,
bool  dtorOnly = false 
)
finalvirtual

Releases the resources acquired during GenerateValue (memory and constructor) This implementation works for simple types but needs to be overwritten for complex ones.

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

Definition at line 1037 of file RField.cxx.

◆ GenerateColumnsImpl() [1/2]

void ROOT::Experimental::RClassField::GenerateColumnsImpl ( )
finalvirtual

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

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

Definition at line 1024 of file RField.cxx.

◆ GenerateColumnsImpl() [2/2]

void ROOT::Experimental::RClassField::GenerateColumnsImpl ( const RNTupleDescriptor desc)
finalvirtual

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 1028 of file RField.cxx.

◆ GenerateValue()

ROOT::Experimental::Detail::RFieldValue ROOT::Experimental::RClassField::GenerateValue ( void *  where)
overridevirtual

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.

Reimplemented in ROOT::Experimental::RField< T, typename >.

Definition at line 1032 of file RField.cxx.

◆ GetAlignment()

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

For many types, the alignment requirement is equal to the size; otherwise override.

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

Definition at line 398 of file RField.hxx.

◆ GetTypeVersion()

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

Indicates an evolution of the C++ type itself.

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

Definition at line 1067 of file RField.cxx.

◆ GetValueSize()

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

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

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

Definition at line 1062 of file RField.cxx.

◆ OnConnectPageSource()

void ROOT::Experimental::RClassField::OnConnectPageSource ( )
finalprotectedvirtual

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

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

Definition at line 998 of file RField.cxx.

◆ operator=()

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

◆ ReadGlobalImpl()

void ROOT::Experimental::RClassField::ReadGlobalImpl ( NTupleSize_t  globalIndex,
Detail::RFieldValue value 
)
finalprotectedvirtual

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

Definition at line 982 of file RField.cxx.

◆ ReadInClusterImpl()

void ROOT::Experimental::RClassField::ReadInClusterImpl ( const RClusterIndex clusterIndex,
Detail::RFieldValue value 
)
finalprotectedvirtual

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

Definition at line 990 of file RField.cxx.

◆ SplitValue()

std::vector< ROOT::Experimental::Detail::RFieldValue > ROOT::Experimental::RClassField::SplitValue ( const Detail::RFieldValue 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::Detail::RFieldBase.

Definition at line 1051 of file RField.cxx.

Member Data Documentation

◆ fClass

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

Definition at line 365 of file RField.hxx.

◆ fMaxAlignment

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

Definition at line 368 of file RField.hxx.

◆ fSubFieldsInfo

std::vector<RSubFieldInfo> ROOT::Experimental::RClassField::fSubFieldsInfo
private

Additional information kept for each entry in fSubFields

Definition at line 367 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 363 of file RField.hxx.

Libraries for ROOT::Experimental::RClassField:
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The documentation for this class was generated from the following files: