Interface for iterating over entries of RNTuples and vertically concatenated RNTuples (chains).

Example usage (see ntpl012_processor.C for a full example):

#include <ROOT/RNTupleProcessor.hxx>
using ROOT::Experimental::RNTupleProcessor;
using ROOT::Experimental::RNTupleOpenSpec;
 
std::vector<RNTupleOpenSpec> ntuples = {{"ntuple1", "ntuple1.root"}, {"ntuple2", "ntuple2.root"}};
auto processor = RNTupleProcessor::CreateChain(ntuples);
 
for (const auto &entry : processor) {
   std::cout << "pt = " << *entry.GetPtr<float>("pt") << std::endl;
}

An RNTupleProcessor is created by providing one or more RNTupleOpenSpecs, each of which contains the name and storage location of a single RNTuple. The RNTuples are processed in the order in which they were provided.

The RNTupleProcessor constructor also (optionally) accepts an RNTupleModel, which determines which fields should be read. If no model is provided, a default model based on the descriptor of the first specified RNTuple will be used. If a field that was present in the first RNTuple is not found in a subsequent one, an error will be thrown.

The RNTupleProcessor provides an iterator which gives access to the REntry containing the field data for the current entry. Additional bookkeeping information can be obtained through the RNTupleProcessor itself.

Definition at line 79 of file RNTupleProcessor.hxx.

Classes
class	RFieldContext
	Manager for a field as part of the RNTupleProcessor. More...

class	RIterator
	Iterator over the entries of an RNTuple, or vertical concatenation thereof. More...

Public Member Functions
	RNTupleProcessor (const RNTupleProcessor &)=delete

	RNTupleProcessor (RNTupleProcessor &&)=delete

virtual	~RNTupleProcessor ()=default

RIterator	begin ()

RIterator	end ()

ROOT::NTupleSize_t	GetCurrentEntryNumber () const
	Get the entry number that is currently being processed.

std::size_t	GetCurrentProcessorNumber () const
	Get the number of the inner processor currently being read.

const REntry &	GetEntry () const
	Get a reference to the entry used by the processor.

const RNTupleModel &	GetModel () const
	Get the model used by the processor.

ROOT::NTupleSize_t	GetNEntriesProcessed () const
	Get the total number of entries processed so far.

const std::string &	GetProcessorName () const
	Get the name of the processor.

RNTupleProcessor &	operator= (const RNTupleProcessor &)=delete

RNTupleProcessor &	operator= (RNTupleProcessor &&)=delete

Static Public Member Functions
static std::unique_ptr< RNTupleProcessor >	Create (const RNTupleOpenSpec &ntuple, std::string_view processorName, std::unique_ptr< RNTupleModel > model=nullptr)
	Create an RNTupleProcessor for a single RNTuple.

static std::unique_ptr< RNTupleProcessor >	Create (const RNTupleOpenSpec &ntuple, std::unique_ptr< RNTupleModel > model=nullptr)
	Create an RNTupleProcessor for a single RNTuple.

static std::unique_ptr< RNTupleProcessor >	CreateChain (const std::vector< RNTupleOpenSpec > &ntuples, std::string_view processorName, std::unique_ptr< RNTupleModel > model=nullptr)
	Create an RNTupleProcessor for a chain (i.e., a vertical combination) of RNTuples.

static std::unique_ptr< RNTupleProcessor >	CreateChain (const std::vector< RNTupleOpenSpec > &ntuples, std::unique_ptr< RNTupleModel > model=nullptr)
	Create an RNTupleProcessor for a chain (i.e., a vertical combination) of RNTuples.

static std::unique_ptr< RNTupleProcessor >	CreateChain (std::vector< std::unique_ptr< RNTupleProcessor > > innerProcessors, std::string_view processorName, std::unique_ptr< RNTupleModel > model=nullptr)
	Create an RNTupleProcessor for a chain (i.e., a vertical combination) of other RNTupleProcessors.

static std::unique_ptr< RNTupleProcessor >	CreateChain (std::vector< std::unique_ptr< RNTupleProcessor > > innerProcessors, std::unique_ptr< RNTupleModel > model=nullptr)
	Create an RNTupleProcessor for a chain (i.e., a vertical combination) of other RNTupleProcessors.

static std::unique_ptr< RNTupleProcessor >	CreateJoin (const std::vector< RNTupleOpenSpec > &ntuples, const std::vector< std::string > &joinFields, std::string_view processorName, std::vector< std::unique_ptr< RNTupleModel > > models={})
	Create an RNTupleProcessor for a join (i.e., a horizontal combination) of RNTuples.

static std::unique_ptr< RNTupleProcessor >	CreateJoin (const std::vector< RNTupleOpenSpec > &ntuples, const std::vector< std::string > &joinFields, std::vector< std::unique_ptr< RNTupleModel > > models={})
	Create an RNTupleProcessor for a join (i.e., a horizontal combination) of RNTuples.

Protected Member Functions
	RNTupleProcessor (std::string_view processorName, std::unique_ptr< RNTupleModel > model)
	Create a new base RNTupleProcessor.

void	ConnectField (RFieldContext &fieldContext, Internal::RPageSource &pageSource, REntry &entry)
	Create and connect a concrete field to the current page source, based on its proto field.

virtual ROOT::NTupleSize_t	GetNEntries ()=0
	Get the total number of entries in this processor.

virtual ROOT::NTupleSize_t	LoadEntry (ROOT::NTupleSize_t entryNumber)=0
	Load the entry identified by the provided entry number.

virtual void	SetEntryPointers (const REntry &entry)=0
	Point the entry's field values of the processor to the pointers from the provided entry.

Protected Attributes
ROOT::NTupleSize_t	fCurrentEntryNumber = 0

std::size_t	fCurrentProcessorNumber = 0

std::unique_ptr< REntry >	fEntry

std::unordered_map< std::string, RFieldContext >	fFieldContexts
	Maps the (qualified) field name to its corresponding field context.

std::unique_ptr< RNTupleModel >	fModel

ROOT::NTupleSize_t	fNEntries = kInvalidNTupleIndex
	Total number of entries.

ROOT::NTupleSize_t	fNEntriesProcessed = 0

std::vector< RNTupleOpenSpec >	fNTuples

std::unique_ptr< Internal::RPageSource >	fPageSource

std::string	fProcessorName

Friends
class	RNTupleChainProcessor

class	RNTupleJoinProcessor

class	RNTupleSingleProcessor

struct	ROOT::Experimental::Internal::RNTupleProcessorEntryLoader

#include <ROOT/RNTupleProcessor.hxx>

Inheritance diagram for ROOT::Experimental::RNTupleProcessor:

[legend]

Constructor & Destructor Documentation

◆ RNTupleProcessor() [1/3]

ROOT::Experimental::RNTupleProcessor::RNTupleProcessor	(	std::string_view	processorName,
		std::unique_ptr< RNTupleModel >	model )

inlineprotected

Create a new base RNTupleProcessor.

Parameters

[in]	processorName	Name of the processor. By default, this is the name of the underlying RNTuple for RNTupleSingleProcessor, the name of the first processor for RNTupleChainProcessor, or the name of the primary RNTuple for RNTupleJoinProcessor.
[in]	model	The RNTupleModel representing the entries returned by the processor.

Note: Before processing, a model must exist. However, this is handled downstream by the RNTupleProcessor's factory functions (CreateSingle, CreateChain and CreateJoin) and constructors.

Definition at line 174 of file RNTupleProcessor.hxx.

◆ RNTupleProcessor() [2/3]

ROOT::Experimental::RNTupleProcessor::RNTupleProcessor ( const RNTupleProcessor & )

delete

◆ RNTupleProcessor() [3/3]

ROOT::Experimental::RNTupleProcessor::RNTupleProcessor ( RNTupleProcessor && )

delete

◆ ~RNTupleProcessor()

virtual ROOT::Experimental::RNTupleProcessor::~RNTupleProcessor ( )

virtualdefault

Member Function Documentation

◆ begin()

RIterator ROOT::Experimental::RNTupleProcessor::begin ( )

inline

Definition at line 273 of file RNTupleProcessor.hxx.

◆ ConnectField()

void ROOT::Experimental::RNTupleProcessor::ConnectField	(	RFieldContext &	fieldContext,
		Internal::RPageSource &	pageSource,
		REntry &	entry )

protected

Create and connect a concrete field to the current page source, based on its proto field.

Definition at line 164 of file RNTupleProcessor.cxx.

◆ Create() [1/2]

std::unique_ptr< ROOT::Experimental::RNTupleProcessor > ROOT::Experimental::RNTupleProcessor::Create	(	const RNTupleOpenSpec &	ntuple,
		std::string_view	processorName,
		std::unique_ptr< RNTupleModel >	model = nullptr )

static

Create an RNTupleProcessor for a single RNTuple.

Parameters

[in]	ntuple	The name and storage location of the RNTuple to process.
[in]	processorName	The name to give to the processor. Use Create(const RNTupleOpenSpec &, std::unique_ptr<RNTupleModel>) to automatically use the name of the input RNTuple instead.
[in]	model	An RNTupleModel specifying which fields can be read by the processor. If no model is provided, one will be created based on the descriptor of the first ntuple specified.

Returns: A pointer to the newly created RNTupleProcessor.

Definition at line 41 of file RNTupleProcessor.cxx.

◆ Create() [2/2]

std::unique_ptr< ROOT::Experimental::RNTupleProcessor > ROOT::Experimental::RNTupleProcessor::Create	(	const RNTupleOpenSpec &	ntuple,
		std::unique_ptr< RNTupleModel >	model = nullptr )

static

Create an RNTupleProcessor for a single RNTuple.

Parameters

[in]	ntuple	The name and storage location of the RNTuple to process.
[in]	model	An RNTupleModel specifying which fields can be read by the processor. If no model is provided, one will be created based on the descriptor of the first ntuple specified.

Returns: A pointer to the newly created RNTupleProcessor.

Definition at line 35 of file RNTupleProcessor.cxx.

◆ CreateChain() [1/4]

std::unique_ptr< ROOT::Experimental::RNTupleProcessor > ROOT::Experimental::RNTupleProcessor::CreateChain	(	const std::vector< RNTupleOpenSpec > &	ntuples,
		std::string_view	processorName,
		std::unique_ptr< RNTupleModel >	model = nullptr )

static

Create an RNTupleProcessor for a chain (i.e., a vertical combination) of RNTuples.

Parameters

[in]	ntuples	A list specifying the names and locations of the RNTuples to process.
[in]	processorName	The name to give to the processor. Use CreateChain(const RNTupleOpenSpec &, std::unique_ptr<RNTupleModel>) to automatically use the name of the first input RNTuple instead.
[in]	model	An RNTupleModel specifying which fields can be read by the processor. If no model is provided, one will be created based on the descriptor of the first RNTuple specified.

Returns: A pointer to the newly created RNTupleProcessor.

Definition at line 58 of file RNTupleProcessor.cxx.

◆ CreateChain() [2/4]

std::unique_ptr< ROOT::Experimental::RNTupleProcessor > ROOT::Experimental::RNTupleProcessor::CreateChain	(	const std::vector< RNTupleOpenSpec > &	ntuples,
		std::unique_ptr< RNTupleModel >	model = nullptr )

static

Create an RNTupleProcessor for a chain (i.e., a vertical combination) of RNTuples.

Parameters

[in]	ntuples	A list specifying the names and locations of the RNTuples to process.
[in]	model	An RNTupleModel specifying which fields can be read by the processor. If no model is provided, one will be created based on the descriptor of the first RNTuple specified.

Returns: A pointer to the newly created RNTupleProcessor.

Definition at line 48 of file RNTupleProcessor.cxx.

◆ CreateChain() [3/4]

std::unique_ptr< ROOT::Experimental::RNTupleProcessor > ROOT::Experimental::RNTupleProcessor::CreateChain	(	std::vector< std::unique_ptr< RNTupleProcessor > >	innerProcessors,
		std::string_view	processorName,
		std::unique_ptr< RNTupleModel >	model = nullptr )

static

Create an RNTupleProcessor for a chain (i.e., a vertical combination) of other RNTupleProcessors.

Parameters

[in]	innerProcessors	A list with the processors to chain.
[in]	processorName	The name to give to the processor. Use CreateChain(std::vector<std::unique_ptr<RNTupleProcessor>>, std::unique_ptr<RNTupleModel>) to automatically use the name of the first inner processor instead.
[in]	model	An RNTupleModel specifying which fields can be read by the processor. If no model is provided, one will be created based on the model used by the first inner processor.

Returns: A pointer to the newly created RNTupleProcessor.

Definition at line 93 of file RNTupleProcessor.cxx.

◆ CreateChain() [4/4]

std::unique_ptr< ROOT::Experimental::RNTupleProcessor > ROOT::Experimental::RNTupleProcessor::CreateChain	(	std::vector< std::unique_ptr< RNTupleProcessor > >	innerProcessors,
		std::unique_ptr< RNTupleModel >	model = nullptr )

static

Create an RNTupleProcessor for a chain (i.e., a vertical combination) of other RNTupleProcessors.

Parameters

[in]	innerProcessors	A list with the processors to chain.
[in]	model	An RNTupleModel specifying which fields can be read by the processor. If no model is provided, one will be created based on the model used by the first inner processor.

Returns: A pointer to the newly created RNTupleProcessor.

Definition at line 82 of file RNTupleProcessor.cxx.

◆ CreateJoin() [1/2]

std::unique_ptr< ROOT::Experimental::RNTupleProcessor > ROOT::Experimental::RNTupleProcessor::CreateJoin	(	const std::vector< RNTupleOpenSpec > &	ntuples,
		const std::vector< std::string > &	joinFields,
		std::string_view	processorName,
		std::vector< std::unique_ptr< RNTupleModel > >	models = {} )

static

Create an RNTupleProcessor for a join (i.e., a horizontal combination) of RNTuples.

Parameters

[in]	ntuples	A list specifying the names and locations of the RNTuples to process. The first RNTuple in the list will be considered the primary RNTuple and drives the processor iteration loop. Subsequent RNTuples are considered auxiliary, whose entries to be read are determined by the primary RNTuple (and do not necessarily have to be in sequential order).
[in]	joinFields	The names of the fields on which to join, in case the specified RNTuples are unaligned. The join is made based on the combined join field values, and therefore each field has to be present in each specified RNTuple. If an empty list is provided, it is assumed that the specified RNTuple are fully aligned.
[in]	processorName	The name to give to the processor. Use CreateJoin(const std::vector<RNTupleOpenSpec> &, const std::vector<std::string> &, std::unique_ptr<RNTupleModel>) to automatically use the name of the input RNTuple instead.
[in]	models	A list of models for the RNTuples. This list must either contain a model for each RNTuple in `ntuples` (following the specification order), or be empty. When the list is empty, the default model (i.e. containing all fields) will be used for each RNTuple.

Returns: A pointer to the newly created RNTupleProcessor.

Definition at line 119 of file RNTupleProcessor.cxx.

◆ CreateJoin() [2/2]

std::unique_ptr< ROOT::Experimental::RNTupleProcessor > ROOT::Experimental::RNTupleProcessor::CreateJoin	(	const std::vector< RNTupleOpenSpec > &	ntuples,
		const std::vector< std::string > &	joinFields,
		std::vector< std::unique_ptr< RNTupleModel > >	models = {} )

static

Create an RNTupleProcessor for a join (i.e., a horizontal combination) of RNTuples.

Parameters

[in]	ntuples	A list specifying the names and locations of the RNTuples to process. The first RNTuple in the list will be considered the primary RNTuple and drives the processor iteration loop. Subsequent RNTuples are considered auxiliary, whose entries to be read are determined by the primary RNTuple (and do not necessarily have to be in sequential order).
[in]	joinFields	The names of the fields on which to join, in case the specified RNTuples are unaligned. The join is made based on the combined join field values, and therefore each field has to be present in each specified RNTuple. If an empty list is provided, it is assumed that the specified ntuple are fully aligned.
[in]	models	A list of models for the RNTuples. This list must either contain a model for each RNTuple in `ntuples` (following the specification order), or be empty. When the list is empty, the default model (i.e. containing all fields) will be used for each RNTuple.

Returns: A pointer to the newly created RNTupleProcessor.

Definition at line 109 of file RNTupleProcessor.cxx.

◆ end()

RIterator ROOT::Experimental::RNTupleProcessor::end ( )

inline

Definition at line 274 of file RNTupleProcessor.hxx.

◆ GetCurrentEntryNumber()

ROOT::NTupleSize_t ROOT::Experimental::RNTupleProcessor::GetCurrentEntryNumber ( ) const

inline

Get the entry number that is currently being processed.

Definition at line 192 of file RNTupleProcessor.hxx.

◆ GetCurrentProcessorNumber()

std::size_t ROOT::Experimental::RNTupleProcessor::GetCurrentProcessorNumber ( ) const

inline

Get the number of the inner processor currently being read.

This method is only relevant for the RNTupleChainProcessor. For the other processors, 0 is always returned.

Definition at line 198 of file RNTupleProcessor.hxx.

◆ GetEntry()

const REntry & ROOT::Experimental::RNTupleProcessor::GetEntry ( ) const

inline

Get a reference to the entry used by the processor.

Returns: A reference to the entry used by the processor.

Definition at line 216 of file RNTupleProcessor.hxx.

◆ GetModel()

const RNTupleModel & ROOT::Experimental::RNTupleProcessor::GetModel ( ) const

inline

Get the model used by the processor.

Definition at line 210 of file RNTupleProcessor.hxx.

◆ GetNEntries()

virtual ROOT::NTupleSize_t ROOT::Experimental::RNTupleProcessor::GetNEntries ( )

protectedpure virtual

Get the total number of entries in this processor.

Implemented in ROOT::Experimental::RNTupleSingleProcessor, ROOT::Experimental::RNTupleChainProcessor, and ROOT::Experimental::RNTupleJoinProcessor.

◆ GetNEntriesProcessed()

ROOT::NTupleSize_t ROOT::Experimental::RNTupleProcessor::GetNEntriesProcessed ( ) const

inline

Get the total number of entries processed so far.

Definition at line 188 of file RNTupleProcessor.hxx.

◆ GetProcessorName()

const std::string & ROOT::Experimental::RNTupleProcessor::GetProcessorName ( ) const

inline

Get the name of the processor.

Unless this name was explicitly specified during creation of the processor, this is the name of the underlying RNTuple for RNTupleSingleProcessor, the name of the first processor for RNTupleChainProcessor, or the name of the primary RNTuple for RNTupleJoinProcessor.

Definition at line 206 of file RNTupleProcessor.hxx.

◆ LoadEntry()

virtual ROOT::NTupleSize_t ROOT::Experimental::RNTupleProcessor::LoadEntry ( ROOT::NTupleSize_t entryNumber )

protectedpure virtual

Load the entry identified by the provided entry number.

Parameters

[in] entryNumber Entry number to load

Returns: entryNumber if the entry was successfully loaded, kInvalidNTupleIndex otherwise.

Implemented in ROOT::Experimental::RNTupleSingleProcessor, ROOT::Experimental::RNTupleChainProcessor, and ROOT::Experimental::RNTupleJoinProcessor.

◆ operator=() [1/2]

RNTupleProcessor & ROOT::Experimental::RNTupleProcessor::operator= ( const RNTupleProcessor & )

delete

◆ operator=() [2/2]

RNTupleProcessor & ROOT::Experimental::RNTupleProcessor::operator= ( RNTupleProcessor && )

delete

◆ SetEntryPointers()

virtual void ROOT::Experimental::RNTupleProcessor::SetEntryPointers ( const REntry & entry )

protectedpure virtual

Point the entry's field values of the processor to the pointers from the provided entry.

Parameters

[in] entry The entry whose field values to use.

Implemented in ROOT::Experimental::RNTupleChainProcessor, ROOT::Experimental::RNTupleJoinProcessor, and ROOT::Experimental::RNTupleSingleProcessor.

Friends And Related Symbol Documentation

◆ RNTupleChainProcessor

friend class RNTupleChainProcessor

friend

Definition at line 82 of file RNTupleProcessor.hxx.

◆ RNTupleJoinProcessor

friend class RNTupleJoinProcessor

friend

Definition at line 83 of file RNTupleProcessor.hxx.

◆ RNTupleSingleProcessor

friend class RNTupleSingleProcessor

friend

Definition at line 81 of file RNTupleProcessor.hxx.

◆ ROOT::Experimental::Internal::RNTupleProcessorEntryLoader

friend struct ROOT::Experimental::Internal::RNTupleProcessorEntryLoader

friend

Definition at line 80 of file RNTupleProcessor.hxx.

Member Data Documentation

◆ fCurrentEntryNumber

ROOT::NTupleSize_t ROOT::Experimental::RNTupleProcessor::fCurrentEntryNumber = 0

protected

Definition at line 139 of file RNTupleProcessor.hxx.

◆ fCurrentProcessorNumber

std::size_t ROOT::Experimental::RNTupleProcessor::fCurrentProcessorNumber = 0

protected

Definition at line 140 of file RNTupleProcessor.hxx.

◆ fEntry

std::unique_ptr<REntry> ROOT::Experimental::RNTupleProcessor::fEntry

protected

Definition at line 127 of file RNTupleProcessor.hxx.

◆ fFieldContexts

std::unordered_map<std::string, RFieldContext> ROOT::Experimental::RNTupleProcessor::fFieldContexts

protected

Maps the (qualified) field name to its corresponding field context.

Definition at line 130 of file RNTupleProcessor.hxx.

◆ fModel

std::unique_ptr<RNTupleModel> ROOT::Experimental::RNTupleProcessor::fModel

protected

Definition at line 132 of file RNTupleProcessor.hxx.

◆ fNEntries

ROOT::NTupleSize_t ROOT::Experimental::RNTupleProcessor::fNEntries = kInvalidNTupleIndex

protected

Total number of entries.

Only to be used internally by the processor, not meant to be exposed in the public interface.

Definition at line 136 of file RNTupleProcessor.hxx.

◆ fNEntriesProcessed

ROOT::NTupleSize_t ROOT::Experimental::RNTupleProcessor::fNEntriesProcessed = 0

protected

Definition at line 138 of file RNTupleProcessor.hxx.

◆ fNTuples

std::vector<RNTupleOpenSpec> ROOT::Experimental::RNTupleProcessor::fNTuples

protected

Definition at line 126 of file RNTupleProcessor.hxx.

◆ fPageSource

std::unique_ptr<Internal::RPageSource> ROOT::Experimental::RNTupleProcessor::fPageSource

protected

Definition at line 128 of file RNTupleProcessor.hxx.

◆ fProcessorName

std::string ROOT::Experimental::RNTupleProcessor::fProcessorName

protected

Definition at line 125 of file RNTupleProcessor.hxx.

Libraries for ROOT::Experimental::RNTupleProcessor:

[legend]

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

tree/ntuple/v7/inc/ROOT/RNTupleProcessor.hxx
tree/ntuple/v7/src/RNTupleProcessor.cxx

Classes

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Friends

Constructor & Destructor Documentation

◆ RNTupleProcessor() [1/3]

◆ RNTupleProcessor() [2/3]

◆ RNTupleProcessor() [3/3]

◆ ~RNTupleProcessor()

Member Function Documentation

◆ begin()

◆ ConnectField()

◆ Create() [1/2]

◆ Create() [2/2]

◆ CreateChain() [1/4]

◆ CreateChain() [2/4]

◆ CreateChain() [3/4]

◆ CreateChain() [4/4]

◆ CreateJoin() [1/2]

◆ CreateJoin() [2/2]

◆ end()

◆ GetCurrentEntryNumber()

◆ GetCurrentProcessorNumber()

◆ GetEntry()

◆ GetModel()

◆ GetNEntries()

◆ GetNEntriesProcessed()

◆ GetProcessorName()

◆ LoadEntry()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ SetEntryPointers()

Friends And Related Symbol Documentation

◆ RNTupleChainProcessor

◆ RNTupleJoinProcessor

◆ RNTupleSingleProcessor

◆ ROOT::Experimental::Internal::RNTupleProcessorEntryLoader

Member Data Documentation

◆ fCurrentEntryNumber

◆ fCurrentProcessorNumber

◆ fEntry

◆ fFieldContexts

◆ fModel

◆ fNEntries

◆ fNEntriesProcessed

◆ fNTuples

◆ fPageSource

◆ fProcessorName