ROOT::Experimental::RNTuple Class Reference

Representation of an RNTuple data set in a ROOT file.

This class provides an API entry point to an RNTuple stored in a ROOT file. Its main purpose is to construct a page source for an RNTuple, which in turn can be used to read an RNTuple with an RDF or an RNTupleReader.

For instance, for an RNTuple called "Events" in a ROOT file, usage can be

auto f = TFile::Open("data.root");
auto ntpl = f->Get<ROOT::Experimental::RNTuple>("Events");
 
auto reader = RNTupleReader::Open(ntpl);
or
auto pageSource = ntpl->MakePageSource();

Definition at line 496 of file RNTuple.hxx.

Public Member Functions
	RNTuple ()=default
	~RNTuple ()=default
TClass *	IsA () const
std::unique_ptr< Detail::RPageSource >	MakePageSource (const RNTupleReadOptions &options=RNTupleReadOptions())
	Create a page source from the RNTuple object.
Long64_t	Merge (TCollection *input, TFileMergeInfo *mergeInfo)
	RNTuple implements the hadd MergeFile interface Merge this NTuple with the input list entries.
void	Streamer (TBuffer &)
void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

Static Public Member Functions
static TClass *	Class ()
static const char *	Class_Name ()
static constexpr Version_t	Class_Version ()
static const char *	DeclFileName ()

Private Member Functions
	RNTuple (const Internal::RFileNTupleAnchor &a)
Internal::RFileNTupleAnchor	GetAnchor () const

Private Attributes
TFile *	fFile = nullptr
	! The file from which the ntuple was streamed, registered in the custom streamer

Friends
class	ROOT::Experimental::Internal::RNTupleFileWriter
struct	ROOT::Experimental::Internal::RNTupleTester

Additional Inherited Members
Protected Attributes inherited from ROOT::Experimental::Internal::RFileNTupleAnchor
std::int32_t	fChecksum = 0
	The ROOT streamer info checksum.
std::uint32_t	fLenFooter = 0
	The size of the uncompressed ntuple footer.
std::uint32_t	fLenHeader = 0
	The size of the uncompressed ntuple header.
std::uint32_t	fNBytesFooter = 0
	The size of the compressed ntuple footer.
std::uint32_t	fNBytesHeader = 0
	The size of the compressed ntuple header.
std::uint64_t	fReserved = 0
	Currently unused, reserved for later use.
std::uint64_t	fSeekFooter = 0
	The file offset of the footer excluding the TKey part.
std::uint64_t	fSeekHeader = 0
	The file offset of the header excluding the TKey part.
std::uint32_t	fSize = sizeof(RFileNTupleAnchor)
	Allows for skipping the struct.
std::uint32_t	fVersion = 0
	Allows for evolving the struct in future versions.

#include <ROOT/RNTuple.hxx>

Inheritance diagram for ROOT::Experimental::RNTuple:

Constructor & Destructor Documentation

RNTuple() [1/2]

ROOT::Experimental::RNTuple::RNTuple ( const Internal::RFileNTupleAnchor &  a )

inlineexplicitprivate

Definition at line 506 of file RNTuple.hxx.

RNTuple() [2/2]

ROOT::Experimental::RNTuple::RNTuple ( )

default

~RNTuple()

ROOT::Experimental::RNTuple::~RNTuple ( )

default

Member Function Documentation

Class()

static TClass * ROOT::Experimental::RNTuple::Class ( )

static

Returns

TClass describing this class

Class_Name()

static const char * ROOT::Experimental::RNTuple::Class_Name ( )

static

Returns

Name of this class

Class_Version()

static constexpr Version_t ROOT::Experimental::RNTuple::Class_Version ( )

inlinestaticconstexpr

Returns

Version of this class

Definition at line 522 of file RNTuple.hxx.

DeclFileName()

static const char * ROOT::Experimental::RNTuple::DeclFileName ( )

inlinestatic

Returns

Name of the file containing the class declaration

Definition at line 522 of file RNTuple.hxx.

GetAnchor()

Internal::RFileNTupleAnchor ROOT::Experimental::RNTuple::GetAnchor ( ) const

inlineprivate

Definition at line 507 of file RNTuple.hxx.

IsA()

TClass * ROOT::Experimental::RNTuple::IsA ( ) const

inline

Returns

TClass describing current object

Definition at line 522 of file RNTuple.hxx.

MakePageSource()

std::unique_ptr< ROOT::Experimental::Detail::RPageSource > ROOT::Experimental::RNTuple::MakePageSource

(

const RNTupleReadOptions &

options = RNTupleReadOptions()

)

Create a page source from the RNTuple object.

Requires the RNTuple object to be streamed from a file. If fFile is not set, an exception is thrown.

Definition at line 414 of file RNTuple.cxx.

Merge()

Long64_t ROOT::Experimental::RNTuple::Merge	(	TCollection *	input,
		TFileMergeInfo *	mergeInfo
	)

RNTuple implements the hadd MergeFile interface Merge this NTuple with the input list entries.

Definition at line 22 of file RNTupleMerger.cxx.

Streamer()

void ROOT::Experimental::RNTuple::Streamer

(

TBuffer &

buf

)

Definition at line 400 of file RNTuple.cxx.

StreamerNVirtual()

void ROOT::Experimental::RNTuple::StreamerNVirtual ( TBuffer &  ClassDef_StreamerNVirtual_b )

inline

Definition at line 522 of file RNTuple.hxx.

Friends And Related Symbol Documentation

ROOT::Experimental::Internal::RNTupleFileWriter

friend class ROOT::Experimental::Internal::RNTupleFileWriter

friend

Definition at line 497 of file RNTuple.hxx.

ROOT::Experimental::Internal::RNTupleTester

friend struct ROOT::Experimental::Internal::RNTupleTester

friend

Definition at line 498 of file RNTuple.hxx.

Member Data Documentation

fFile

TFile* ROOT::Experimental::RNTuple::fFile = nullptr

private

! The file from which the ntuple was streamed, registered in the custom streamer

Definition at line 503 of file RNTuple.hxx.

Libraries for ROOT::Experimental::RNTuple:

---

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

• tree/ntuple/v7/inc/ROOT/RNTuple.hxx
• tree/ntuple/v7/src/RNTuple.cxx
• tree/ntuple/v7/src/RNTupleMerger.cxx