ROOT::RDF::RResultHandle Class Reference

A type-erased version of RResultPtr and RResultMap.

RResultHandles are used to invoke ROOT::RDF::RunGraphs() and can also be useful to store result pointers of different types in the same collection. Knowledge about the actual result type will still be needed to access it.

Note

Varied results are stripped away when a RResultMap is converted to a RResultHandle: Only the nominal result will be accessible from the RResultHandle.

Definition at line 33 of file RResultHandle.hxx.

Public Member Functions
	RResultHandle ()=default
template<class T >
	RResultHandle (const Experimental::RResultMap< T > &resultMap)
	RResultHandle (const RResultHandle &)=default
template<class T >
	RResultHandle (const RResultPtr< T > &resultPtr)
	RResultHandle (RResultHandle &&)=default
template<class T >
T *	GetPtr ()
	Get the pointer to the encapsulated object.
template<class T >
const T &	GetValue ()
	Get a const reference to the encapsulated object.
bool	IsReady () const
	Check whether the result has already been computed.
bool	operator!= (const RResultHandle &rhs) const
bool	operator== (const RResultHandle &rhs) const
template<class T >
	R__DEPRECATED (6, 32, "Please use RResultPtr directly and only cast to RResultHandle in order to call RunGraphs.") RResultPtr< T > GetResultPtr()
	Get an RResultPtr to the encapsulated object.

Private Member Functions
void	CheckType (const std::type_info &type)
	Compare given type to the type of the wrapped result and throw if the types don't match.
void *	Get ()
	Get the pointer to the encapsulated result.
void	ThrowIfNull ()

Private Attributes
std::shared_ptr< ROOT::Internal::RDF::RActionBase >	fActionPtr
	Owning pointer to the action that will produce this result.
ROOT::Detail::RDF::RLoopManager *	fLoopManager = nullptr
std::shared_ptr< void >	fObjPtr
	Type erased shared pointer encapsulating the wrapped result.
const std::type_info *	fType = nullptr
	Type of the wrapped result.
std::shared_ptr< ROOT::Internal::RDF::RActionBase >	fVariedActionPtr
	Owning pointer to the varied action that will produce these results if any.

Friends
unsigned int	RunGraphs (std::vector< RResultHandle >)
	Trigger the event loop of multiple RDataFrames concurrently.

#include <ROOT/RResultHandle.hxx>

Constructor & Destructor Documentation

RResultHandle() [1/5]

template<class T >

ROOT::RDF::RResultHandle::RResultHandle ( const RResultPtr< T > &  resultPtr )

inline

Definition at line 77 of file RResultHandle.hxx.

RResultHandle() [2/5]

template<class T >

ROOT::RDF::RResultHandle::RResultHandle ( const Experimental::RResultMap< T > &  resultMap )

inline

Definition at line 79 of file RResultHandle.hxx.

RResultHandle() [3/5]

ROOT::RDF::RResultHandle::RResultHandle ( const RResultHandle &  )

default

RResultHandle() [4/5]

ROOT::RDF::RResultHandle::RResultHandle ( RResultHandle &&  )

default

RResultHandle() [5/5]

ROOT::RDF::RResultHandle::RResultHandle ( )

default

Member Function Documentation

CheckType()

void ROOT::RDF::RResultHandle::CheckType ( const std::type_info &  type )

inlineprivate

Compare given type to the type of the wrapped result and throw if the types don't match.

Definition at line 58 of file RResultHandle.hxx.

Get()

void * ROOT::RDF::RResultHandle::Get ( )

inlineprivate

Get the pointer to the encapsulated result.

Ownership is not transferred to the caller. Triggers event loop and execution of all actions booked in the associated RLoopManager.

Definition at line 50 of file RResultHandle.hxx.

GetPtr()

template<class T >

T * ROOT::RDF::RResultHandle::GetPtr ( )

inline

Get the pointer to the encapsulated object.

Triggers event loop and execution of all actions booked in the associated RLoopManager. If the RResultHandle was created from a RResultMap, this returns a pointer to the nominal value.

Template Parameters

T	Type of the action result

Definition at line 97 of file RResultHandle.hxx.

GetValue()

template<class T >

const T & ROOT::RDF::RResultHandle::GetValue ( )

inline

Get a const reference to the encapsulated object.

Triggers event loop and execution of all actions booked in the associated RLoopManager. If the RResultHandle was created from a RResultMap, this returns a pointer to the nominal value.

Template Parameters

T	Type of the action result

Definition at line 109 of file RResultHandle.hxx.

IsReady()

bool ROOT::RDF::RResultHandle::IsReady ( ) const

inline

Check whether the result has already been computed.

std::vector<RResultHandle> results;
results.emplace_back(df.Mean<double>("var"));
res.IsReady(); // false, access will trigger event loop
std::cout << res.GetValue<double>() << std::endl; // triggers event loop
res.IsReady(); // true

Definition at line 135 of file RResultHandle.hxx.

operator!=()

bool ROOT::RDF::RResultHandle::operator!= ( const RResultHandle &  rhs ) const

inline

Definition at line 146 of file RResultHandle.hxx.

operator==()

bool ROOT::RDF::RResultHandle::operator== ( const RResultHandle &  rhs ) const

inline

Definition at line 141 of file RResultHandle.hxx.

R__DEPRECATED()

template<class T >

ROOT::RDF::RResultHandle::R__DEPRECATED ( 6  , 32  , "Please use RResultPtr directly and only cast to RResultHandle in order to call RunGraphs."    )

inline

Get an RResultPtr to the encapsulated object.

Template Parameters

T	Type of the action result

Definition at line 119 of file RResultHandle.hxx.

ThrowIfNull()

void ROOT::RDF::RResultHandle::ThrowIfNull ( )

inlineprivate

Definition at line 69 of file RResultHandle.hxx.

Friends And Related Symbol Documentation

RunGraphs

unsigned int RunGraphs ( std::vector< RResultHandle >  )

friend

Trigger the event loop of multiple RDataFrames concurrently.

Parameters

[in]

handles

A vector of RResultHandles

Returns

The number of distinct computation graphs that have been processed

This function triggers the event loop of all computation graphs which relate to the given RResultHandles. The advantage compared to running the event loop implicitly by accessing the RResultPtr is that the event loops will run concurrently. Therefore, the overall computation of all results is generally more efficient. It should be noted that user-defined operations (e.g., Filters and Defines) of the different RDataFrame graphs are assumed to be safe to call concurrently.

ROOT::RDataFrame df1("tree1", "file1.root");
auto r1 = df1.Histo1D("var1");
 
ROOT::RDataFrame df2("tree2", "file2.root");
auto r2 = df2.Sum("var2");
 
// RResultPtr -> RResultHandle conversion is automatic
ROOT::RDF::RunGraphs({r1, r2});

Member Data Documentation

fActionPtr

std::shared_ptr<ROOT::Internal::RDF::RActionBase> ROOT::RDF::RResultHandle::fActionPtr

private

Owning pointer to the action that will produce this result.

Ownership is shared with RResultPtrs and RResultHandles that refer to the same result.

Definition at line 37 of file RResultHandle.hxx.

fLoopManager

ROOT::Detail::RDF::RLoopManager* ROOT::RDF::RResultHandle::fLoopManager = nullptr

private

Definition at line 34 of file RResultHandle.hxx.

fObjPtr

std::shared_ptr<void> ROOT::RDF::RResultHandle::fObjPtr

private

Type erased shared pointer encapsulating the wrapped result.

Definition at line 38 of file RResultHandle.hxx.

fType

const std::type_info* ROOT::RDF::RResultHandle::fType = nullptr

private

Type of the wrapped result.

Definition at line 42 of file RResultHandle.hxx.

fVariedActionPtr

std::shared_ptr<ROOT::Internal::RDF::RActionBase> ROOT::RDF::RResultHandle::fVariedActionPtr

private

Owning pointer to the varied action that will produce these results if any.

Null if the RResultHandle was created from a RResultPtr, so no variations were present.

Definition at line 41 of file RResultHandle.hxx.

Libraries for ROOT::RDF::RResultHandle:

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

• tree/dataframe/inc/ROOT/RResultHandle.hxx