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Reference Guide
ROOT::Experimental::RNTupleDS Class Referencefinal

Definition at line 45 of file RNTupleDS.hxx.

Public Member Functions

 RNTupleDS (std::unique_ptr< ROOT::Experimental::Detail::RPageSource > pageSource)
 
 ~RNTupleDS ()
 
void Finalise () final
 Convenience method called after concluding an event-loop. More...
 
const std::vector< std::string > & GetColumnNames () const final
 Returns a reference to the collection of the dataset's column names. More...
 
std::unique_ptr< ROOT::Detail::RDF::RColumnReaderBaseGetColumnReaders (unsigned int, std::string_view, const std::type_info &) final
 If the other GetColumnReaders overload returns an empty vector, this overload will be called instead. More...
 
std::vector< std::pair< ULong64_t, ULong64_t > > GetEntryRanges () final
 Return ranges of entries to distribute to tasks. More...
 
std::string GetLabel () final
 Return a string representation of the datasource type. More...
 
std::string GetTypeName (std::string_view colName) const final
 Type of a column as a string, e.g. More...
 
bool HasColumn (std::string_view colName) const final
 Checks if the dataset has a certain column. More...
 
void Initialise () final
 Convenience method called before starting an event-loop. More...
 
bool SetEntry (unsigned int slot, ULong64_t entry) final
 Advance the "cursors" returned by GetColumnReaders to the selected entry for a particular slot. More...
 
void SetNSlots (unsigned int nSlots) final
 Inform RDataSource of the number of processing slots (i.e. More...
 
- Public Member Functions inherited from ROOT::RDF::RDataSource
virtual ~RDataSource ()=default
 
virtual void Finalise ()
 Convenience method called after concluding an event-loop. More...
 
virtual void FinaliseSlot (unsigned int)
 Convenience method called at the end of the data processing associated to a slot. More...
 
virtual const std::vector< std::string > & GetColumnNames () const =0
 Returns a reference to the collection of the dataset's column names. More...
 
template<typename T >
std::vector< T ** > GetColumnReaders (std::string_view columnName)
 Called at most once per column by RDF. More...
 
virtual std::unique_ptr< ROOT::Detail::RDF::RColumnReaderBaseGetColumnReaders (unsigned int, std::string_view, const std::type_info &)
 If the other GetColumnReaders overload returns an empty vector, this overload will be called instead. More...
 
virtual std::vector< std::pair< ULong64_t, ULong64_t > > GetEntryRanges ()=0
 Return ranges of entries to distribute to tasks. More...
 
virtual std::string GetLabel ()
 Return a string representation of the datasource type. More...
 
virtual std::string GetTypeName (std::string_view colName) const =0
 Type of a column as a string, e.g. More...
 
virtual bool HasColumn (std::string_view colName) const =0
 Checks if the dataset has a certain column. More...
 
virtual void Initialise ()
 Convenience method called before starting an event-loop. More...
 
virtual void InitSlot (unsigned int, ULong64_t)
 Convenience method called at the start of the data processing associated to a slot. More...
 
virtual bool SetEntry (unsigned int slot, ULong64_t entry)=0
 Advance the "cursors" returned by GetColumnReaders to the selected entry for a particular slot. More...
 
virtual void SetNSlots (unsigned int nSlots)=0
 Inform RDataSource of the number of processing slots (i.e. More...
 

Protected Member Functions

Record_t GetColumnReadersImpl (std::string_view name, const std::type_info &) final
 type-erased vector of pointers to pointers to column values - one per slot More...
 
- Protected Member Functions inherited from ROOT::RDF::RDataSource
virtual std::string AsString ()
 
virtual Record_t GetColumnReadersImpl (std::string_view name, const std::type_info &)=0
 type-erased vector of pointers to pointers to column values - one per slot More...
 

Private Member Functions

void AddField (const RNTupleDescriptor &desc, std::string_view colName, DescriptorId_t fieldId, std::vector< DescriptorId_t > skeinIDs)
 Provides the RDF column "colName" given the field identified by fieldID. More...
 

Private Attributes

std::vector< size_t > fActiveColumns
 
std::vector< std::string > fColumnNames
 
std::vector< std::unique_ptr< ROOT::Experimental::Internal::RNTupleColumnReader > > fColumnReaderPrototypes
 We prepare a column reader prototype for every column. More...
 
std::vector< std::string > fColumnTypes
 
bool fHasSeenAllRanges = false
 
unsigned fNSlots = 0
 
std::vector< std::unique_ptr< ROOT::Experimental::Detail::RPageSource > > fSources
 Clones of the first source, one for each slot. More...
 

Additional Inherited Members

- Protected Types inherited from ROOT::RDF::RDataSource
using Record_t = std::vector< void * >
 

#include <ROOT/RNTupleDS.hxx>

Inheritance diagram for ROOT::Experimental::RNTupleDS:
[legend]

Constructor & Destructor Documentation

◆ RNTupleDS()

ROOT::Experimental::RNTupleDS::RNTupleDS ( std::unique_ptr< ROOT::Experimental::Detail::RPageSource pageSource)
explicit

Definition at line 244 of file RNTupleDS.cxx.

◆ ~RNTupleDS()

ROOT::Experimental::RNTupleDS::~RNTupleDS ( )
default

Member Function Documentation

◆ AddField()

void ROOT::Experimental::RNTupleDS::AddField ( const RNTupleDescriptor desc,
std::string_view  colName,
DescriptorId_t  fieldId,
std::vector< DescriptorId_t skeinIDs 
)
private

Provides the RDF column "colName" given the field identified by fieldID.

For records and collections, AddField recurses into the sub fields. The skeinIDs is the list of field IDs of the outer collections of fieldId. For instance, if fieldId refers to an std::vector<Jet>, with struct Jet { float pt; float eta; }; AddField will recurse into Jet.pt and Jet.eta and provide the two inner fields as std::vector<float> each.

Definition at line 146 of file RNTupleDS.cxx.

◆ Finalise()

void ROOT::Experimental::RNTupleDS::Finalise ( )
finalvirtual

Convenience method called after concluding an event-loop.

See Initialise for more details.

Reimplemented from ROOT::RDF::RDataSource.

Definition at line 314 of file RNTupleDS.cxx.

◆ GetColumnNames()

const std::vector< std::string > & ROOT::Experimental::RNTupleDS::GetColumnNames ( ) const
inlinefinalvirtual

Returns a reference to the collection of the dataset's column names.

Implements ROOT::RDF::RDataSource.

Definition at line 77 of file RNTupleDS.hxx.

◆ GetColumnReaders()

std::unique_ptr< ROOT::Detail::RDF::RColumnReaderBase > ROOT::Experimental::RNTupleDS::GetColumnReaders ( unsigned int  ,
std::string_view  ,
const std::type_info &   
)
finalvirtual

If the other GetColumnReaders overload returns an empty vector, this overload will be called instead.

Parameters
[in]slotThe data processing slot that needs to be considered
[in]nameThe name of the column for which a column reader needs to be returned
[in]tidA type_info At least one of the two must return a non-empty/non-null value.

Reimplemented from ROOT::RDF::RDataSource.

Definition at line 260 of file RNTupleDS.cxx.

◆ GetColumnReadersImpl()

RDF::RDataSource::Record_t ROOT::Experimental::RNTupleDS::GetColumnReadersImpl ( std::string_view  name,
const std::type_info &   
)
finalprotectedvirtual

type-erased vector of pointers to pointers to column values - one per slot

Implements ROOT::RDF::RDataSource.

Definition at line 253 of file RNTupleDS.cxx.

◆ GetEntryRanges()

std::vector< std::pair< ULong64_t, ULong64_t > > ROOT::Experimental::RNTupleDS::GetEntryRanges ( )
finalvirtual

Return ranges of entries to distribute to tasks.

They are required to be contiguous intervals with no entries skipped. Supposing a dataset with nEntries, the intervals must start at 0 and end at nEntries, e.g. [0-5],[5-10] for 10 entries. This function will be invoked repeatedly by RDataFrame as it needs additional entries to process. The same entry range should not be returned more than once. Returning an empty collection of ranges signals to RDataFrame that the processing can stop.

Implements ROOT::RDF::RDataSource.

Definition at line 275 of file RNTupleDS.cxx.

◆ GetLabel()

std::string ROOT::Experimental::RNTupleDS::GetLabel ( )
inlinefinalvirtual

Return a string representation of the datasource type.

The returned string will be used by ROOT::RDF::SaveGraph() to represent the datasource in the visualization of the computation graph. Concrete datasources can override the default implementation.

Reimplemented from ROOT::RDF::RDataSource.

Definition at line 81 of file RNTupleDS.hxx.

◆ GetTypeName()

std::string ROOT::Experimental::RNTupleDS::GetTypeName ( std::string_view  colName) const
finalvirtual

Type of a column as a string, e.g.

GetTypeName("x") == "double". Required for jitting e.g. df.Filter("x>0").

Parameters
[in]colNameThe name of the column

Implements ROOT::RDF::RDataSource.

Definition at line 298 of file RNTupleDS.cxx.

◆ HasColumn()

bool ROOT::Experimental::RNTupleDS::HasColumn ( std::string_view  colName) const
finalvirtual

Checks if the dataset has a certain column.

Parameters
[in]colNameThe name of the column

Implements ROOT::RDF::RDataSource.

Definition at line 304 of file RNTupleDS.cxx.

◆ Initialise()

void ROOT::Experimental::RNTupleDS::Initialise ( )
finalvirtual

Convenience method called before starting an event-loop.

This method might be called multiple times over the lifetime of a RDataSource, since users can run multiple event-loops with the same RDataFrame. Ideally, Initialise should set the state of the RDataSource so that multiple identical event-loops will produce identical results.

Reimplemented from ROOT::RDF::RDataSource.

Definition at line 309 of file RNTupleDS.cxx.

◆ SetEntry()

bool ROOT::Experimental::RNTupleDS::SetEntry ( unsigned int  slot,
ULong64_t  entry 
)
finalvirtual

Advance the "cursors" returned by GetColumnReaders to the selected entry for a particular slot.

Parameters
[in]slotThe data processing slot that needs to be considered
[in]entryThe entry which needs to be pointed to by the reader pointers Slots are adopted to accommodate parallel data processing. Different workers will loop over different ranges and will be labelled by different "slot" values. Returns true if the entry has to be processed, false otherwise.

Implements ROOT::RDF::RDataSource.

Definition at line 270 of file RNTupleDS.cxx.

◆ SetNSlots()

void ROOT::Experimental::RNTupleDS::SetNSlots ( unsigned int  nSlots)
finalvirtual

Inform RDataSource of the number of processing slots (i.e.

worker threads) used by the associated RDataFrame. Slots numbers are used to simplify parallel execution: RDataFrame guarantees that different threads will always pass different slot values when calling methods concurrently.

Implements ROOT::RDF::RDataSource.

Definition at line 316 of file RNTupleDS.cxx.

Member Data Documentation

◆ fActiveColumns

std::vector<size_t> ROOT::Experimental::RNTupleDS::fActiveColumns
private

Definition at line 55 of file RNTupleDS.hxx.

◆ fColumnNames

std::vector<std::string> ROOT::Experimental::RNTupleDS::fColumnNames
private

Definition at line 53 of file RNTupleDS.hxx.

◆ fColumnReaderPrototypes

std::vector<std::unique_ptr<ROOT::Experimental::Internal::RNTupleColumnReader> > ROOT::Experimental::RNTupleDS::fColumnReaderPrototypes
private

We prepare a column reader prototype for every column.

If a column reader is actually requested in GetColumnReaders(), we move a clone of the prototype into the hands of RDataFrame. Only the clone connects to the backing page store and acquires I/O resources.

Definition at line 52 of file RNTupleDS.hxx.

◆ fColumnTypes

std::vector<std::string> ROOT::Experimental::RNTupleDS::fColumnTypes
private

Definition at line 54 of file RNTupleDS.hxx.

◆ fHasSeenAllRanges

bool ROOT::Experimental::RNTupleDS::fHasSeenAllRanges = false
private

Definition at line 58 of file RNTupleDS.hxx.

◆ fNSlots

unsigned ROOT::Experimental::RNTupleDS::fNSlots = 0
private

Definition at line 57 of file RNTupleDS.hxx.

◆ fSources

std::vector<std::unique_ptr<ROOT::Experimental::Detail::RPageSource> > ROOT::Experimental::RNTupleDS::fSources
private

Clones of the first source, one for each slot.

Definition at line 47 of file RNTupleDS.hxx.


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