Representation of an RNTuple data set in a ROOT file.

The class points to the header and footer keys, which in turn have the references to the pages (via page lists). Only the RNTuple key will be listed in the list of keys. Like TBaskets, the pages are "invisible" keys. Byte offset references in the RNTuple header and footer reference directly the data part of page records, skipping the TFile key part.

In the list of keys, this object appears as "ROOT::RNTuple". It is the user-facing representation of an RNTuple data set in a ROOT file and it 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::RNTuple>("Events");
auto reader = RNTupleReader::Open(ntpl);

Definition at line 69 of file RNTuple.hxx.

Public Member Functions
	RNTuple ()=default

	~RNTuple ()=default

std::uint64_t	GetLenFooter () const

std::uint64_t	GetLenHeader () const

std::uint64_t	GetMaxKeySize () const

std::uint64_t	GetNBytesFooter () const

std::uint64_t	GetNBytesHeader () const

std::uint64_t	GetSeekFooter () const

std::uint64_t	GetSeekHeader () const

std::uint16_t	GetVersionEpoch () const

std::uint16_t	GetVersionMajor () const

std::uint16_t	GetVersionMinor () const

std::uint16_t	GetVersionPatch () const

TClass *	IsA () const

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 ()
	NOTE: if you change this version you also need to update RTFNTuple::fClassVersion in RMiniFile.cxx.

static const char *	DeclFileName ()

Static Public Attributes
static constexpr std::uint16_t	kVersionEpoch = 0

static constexpr std::uint16_t	kVersionMajor = 3

static constexpr std::uint16_t	kVersionMinor = 0

static constexpr std::uint16_t	kVersionPatch = 0

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

std::uint64_t	fLenFooter = 0
	The size of the uncompressed ntuple footer.

std::uint64_t	fLenHeader = 0
	The size of the uncompressed ntuple header.

std::uint64_t	fMaxKeySize = 0
	The maximum size for a TKey payload. Payloads bigger than this size will be written as multiple blobs.

std::uint64_t	fNBytesFooter = 0
	The size of the compressed ntuple footer.

std::uint64_t	fNBytesHeader = 0
	The size of the compressed ntuple header.

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::uint16_t	fVersionEpoch = kVersionEpoch
	Version of the RNTuple binary format that the writer supports (see specification).

std::uint16_t	fVersionMajor = kVersionMajor
	Changing the major version indicates forward incompatible changes; such changes should correspond to a new bit in the feature flag of the RNTuple header.

std::uint16_t	fVersionMinor = kVersionMinor
	Changing the minor version indicates new optional fields added to the RNTuple meta-data.

std::uint16_t	fVersionPatch = kVersionPatch
	Changing the patch version indicates new backported features from newer binary format versions.

Friends
class	Experimental::Internal::RNTupleFileWriter

class	Experimental::Internal::RPageSourceFile

ROOT::RNTuple	ROOT::Experimental::Internal::CreateAnchor (std::uint16_t versionEpoch, std::uint16_t versionMajor, std::uint16_t versionMinor, std::uint16_t versionPatch, std::uint64_t seekHeader, std::uint64_t nbytesHeader, std::uint64_t lenHeader, std::uint64_t seekFooter, std::uint64_t nbytesFooter, std::uint64_t lenFooter, std::uint64_t maxKeySize)

#include <ROOT/RNTuple.hxx>

Constructor & Destructor Documentation

◆ RNTuple()

ROOT::RNTuple::RNTuple ( )

default

◆ ~RNTuple()

ROOT::RNTuple::~RNTuple ( )

default

Member Function Documentation

◆ Class()

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

static

Returns: TClass describing this class

◆ Class_Name()

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

static

Returns: Name of this class

◆ Class_Version()

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

inlinestaticconstexpr

NOTE: if you change this version you also need to update RTFNTuple::fClassVersion in RMiniFile.cxx.

Returns: Version of this class

Definition at line 136 of file RNTuple.hxx.

◆ DeclFileName()

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

inlinestatic

Returns: Name of the file containing the class declaration

Definition at line 136 of file RNTuple.hxx.

◆ GetLenFooter()

std::uint64_t ROOT::RNTuple::GetLenFooter ( ) const

inline

Definition at line 128 of file RNTuple.hxx.

◆ GetLenHeader()

std::uint64_t ROOT::RNTuple::GetLenHeader ( ) const

inline

Definition at line 124 of file RNTuple.hxx.

◆ GetMaxKeySize()

std::uint64_t ROOT::RNTuple::GetMaxKeySize ( ) const

inline

Definition at line 129 of file RNTuple.hxx.

◆ GetNBytesFooter()

std::uint64_t ROOT::RNTuple::GetNBytesFooter ( ) const

inline

Definition at line 127 of file RNTuple.hxx.

◆ GetNBytesHeader()

std::uint64_t ROOT::RNTuple::GetNBytesHeader ( ) const

inline

Definition at line 123 of file RNTuple.hxx.

◆ GetSeekFooter()

std::uint64_t ROOT::RNTuple::GetSeekFooter ( ) const

inline

Definition at line 126 of file RNTuple.hxx.

◆ GetSeekHeader()

std::uint64_t ROOT::RNTuple::GetSeekHeader ( ) const

inline

Definition at line 122 of file RNTuple.hxx.

◆ GetVersionEpoch()

std::uint16_t ROOT::RNTuple::GetVersionEpoch ( ) const

inline

Definition at line 117 of file RNTuple.hxx.

◆ GetVersionMajor()

std::uint16_t ROOT::RNTuple::GetVersionMajor ( ) const

inline

Definition at line 118 of file RNTuple.hxx.

◆ GetVersionMinor()

std::uint16_t ROOT::RNTuple::GetVersionMinor ( ) const

inline

Definition at line 119 of file RNTuple.hxx.

◆ GetVersionPatch()

std::uint16_t ROOT::RNTuple::GetVersionPatch ( ) const

inline

Definition at line 120 of file RNTuple.hxx.

◆ IsA()

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

inline

Returns: TClass describing current object

Definition at line 136 of file RNTuple.hxx.

◆ Merge()

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

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

Definition at line 45 of file RNTupleMerger.cxx.

◆ Streamer()

void ROOT::RNTuple::Streamer ( TBuffer & buf )

Definition at line 27 of file RNTuple.cxx.

◆ StreamerNVirtual()

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

inline

Definition at line 136 of file RNTuple.hxx.

Friends And Related Symbol Documentation

◆ Experimental::Internal::RNTupleFileWriter

friend class Experimental::Internal::RNTupleFileWriter

friend

Definition at line 70 of file RNTuple.hxx.

◆ Experimental::Internal::RPageSourceFile

friend class Experimental::Internal::RPageSourceFile

friend

Definition at line 71 of file RNTuple.hxx.

◆ ROOT::Experimental::Internal::CreateAnchor

ROOT::RNTuple ROOT::Experimental::Internal::CreateAnchor	(	std::uint16_t	versionEpoch,
		std::uint16_t	versionMajor,
		std::uint16_t	versionMinor,
		std::uint16_t	versionPatch,
		std::uint64_t	seekHeader,
		std::uint64_t	nbytesHeader,
		std::uint64_t	lenHeader,
		std::uint64_t	seekFooter,
		std::uint64_t	nbytesFooter,
		std::uint64_t	lenFooter,
		std::uint64_t	maxKeySize
	)

friend

Member Data Documentation

◆ fFile

TFile* ROOT::RNTuple::fFile = nullptr

private

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

Definition at line 111 of file RNTuple.hxx.

◆ fLenFooter

std::uint64_t ROOT::RNTuple::fLenFooter = 0

private

The size of the uncompressed ntuple footer.

Definition at line 107 of file RNTuple.hxx.

◆ fLenHeader

std::uint64_t ROOT::RNTuple::fLenHeader = 0

private

The size of the uncompressed ntuple header.

Definition at line 101 of file RNTuple.hxx.

◆ fMaxKeySize

std::uint64_t ROOT::RNTuple::fMaxKeySize = 0

private

The maximum size for a TKey payload. Payloads bigger than this size will be written as multiple blobs.

Definition at line 109 of file RNTuple.hxx.

◆ fNBytesFooter

std::uint64_t ROOT::RNTuple::fNBytesFooter = 0

private

The size of the compressed ntuple footer.

Definition at line 105 of file RNTuple.hxx.

◆ fNBytesHeader

std::uint64_t ROOT::RNTuple::fNBytesHeader = 0

private

The size of the compressed ntuple header.

Definition at line 99 of file RNTuple.hxx.

◆ fSeekFooter

std::uint64_t ROOT::RNTuple::fSeekFooter = 0

private

The file offset of the footer excluding the TKey part.

Definition at line 103 of file RNTuple.hxx.

◆ fSeekHeader

std::uint64_t ROOT::RNTuple::fSeekHeader = 0

private

The file offset of the header excluding the TKey part.

Definition at line 97 of file RNTuple.hxx.

◆ fVersionEpoch

std::uint16_t ROOT::RNTuple::fVersionEpoch = kVersionEpoch

private

Version of the RNTuple binary format that the writer supports (see specification).

Changing the epoch indicates backward-incompatible changes

Definition at line 87 of file RNTuple.hxx.

◆ fVersionMajor

std::uint16_t ROOT::RNTuple::fVersionMajor = kVersionMajor

private

Changing the major version indicates forward incompatible changes; such changes should correspond to a new bit in the feature flag of the RNTuple header.

For the pre-release epoch 0, indicates the release candidate number

Definition at line 91 of file RNTuple.hxx.

◆ fVersionMinor

std::uint16_t ROOT::RNTuple::fVersionMinor = kVersionMinor

private

Changing the minor version indicates new optional fields added to the RNTuple meta-data.

Definition at line 93 of file RNTuple.hxx.

◆ fVersionPatch

std::uint16_t ROOT::RNTuple::fVersionPatch = kVersionPatch

private

Changing the patch version indicates new backported features from newer binary format versions.

Definition at line 95 of file RNTuple.hxx.

◆ kVersionEpoch

constexpr std::uint16_t ROOT::RNTuple::kVersionEpoch = 0

staticconstexpr

Definition at line 79 of file RNTuple.hxx.

◆ kVersionMajor

constexpr std::uint16_t ROOT::RNTuple::kVersionMajor = 3

staticconstexpr

Definition at line 80 of file RNTuple.hxx.

◆ kVersionMinor

constexpr std::uint16_t ROOT::RNTuple::kVersionMinor = 0

staticconstexpr

Definition at line 81 of file RNTuple.hxx.

◆ kVersionPatch

constexpr std::uint16_t ROOT::RNTuple::kVersionPatch = 0

staticconstexpr

Definition at line 82 of file RNTuple.hxx.

Libraries for ROOT::RNTuple:

[legend]

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

Public Member Functions

Static Public Member Functions

Static Public Attributes

Private Attributes

Friends

Constructor & Destructor Documentation

◆ RNTuple()

◆ ~RNTuple()

Member Function Documentation

◆ Class()

◆ Class_Name()

◆ Class_Version()

◆ DeclFileName()

◆ GetLenFooter()

◆ GetLenHeader()

◆ GetMaxKeySize()

◆ GetNBytesFooter()

◆ GetNBytesHeader()

◆ GetSeekFooter()

◆ GetSeekHeader()

◆ GetVersionEpoch()

◆ GetVersionMajor()

◆ GetVersionMinor()

◆ GetVersionPatch()

◆ IsA()

◆ Merge()

◆ Streamer()

◆ StreamerNVirtual()

Friends And Related Symbol Documentation

◆ Experimental::Internal::RNTupleFileWriter

◆ Experimental::Internal::RPageSourceFile

◆ ROOT::Experimental::Internal::CreateAnchor

Member Data Documentation

◆ fFile

◆ fLenFooter

◆ fLenHeader

◆ fMaxKeySize

◆ fNBytesFooter

◆ fNBytesHeader

◆ fSeekFooter

◆ fSeekHeader

◆ fVersionEpoch

◆ fVersionMajor

◆ fVersionMinor

◆ fVersionPatch

◆ kVersionEpoch

◆ kVersionMajor

◆ kVersionMinor

◆ kVersionPatch