An RNTuple that gets filled with entries (data) and writes them to storage.

An output ntuple can be filled with entries. The caller has to make sure that the data that gets filled into an ntuple is not modified for the time of the Fill() call. The fill call serializes the C++ object into the column format and writes data into the corresponding column page buffers. Writing of the buffers to storage is deferred and can be triggered by Flush() or by destructing the ntuple. On I/O errors, an exception is thrown.

Definition at line 358 of file RNTuple.hxx.

Public Member Functions
	RNTupleWriter (const RNTupleWriter &)=delete

	RNTupleWriter (std::unique_ptr< RNTupleModel > model, std::unique_ptr< Detail::RPageSink > sink)
	Throws an exception if the model or the sink is null.

	~RNTupleWriter ()

void	CommitCluster (bool commitClusterGroup=false)
	Ensure that the data from the so far seen Fill calls has been written to storage.

std::unique_ptr< REntry >	CreateEntry ()

std::unique_ptr< RNTupleModel::RUpdater >	CreateModelUpdater ()
	Get a `RNTupleModel::RUpdater` that provides limited support for incremental updates to the underlying model, e.g.

void	EnableMetrics ()

std::size_t	Fill ()
	The simplest user interface if the default entry that comes with the ntuple model is used.

std::size_t	Fill (REntry &entry)
	Multiple entries can have been instantiated from the ntuple model.

const Detail::RNTupleMetrics &	GetMetrics () const

const RNTupleModel *	GetModel () const

RNTupleWriter &	operator= (const RNTupleWriter &)=delete

Static Public Member Functions
static std::unique_ptr< RNTupleWriter >	Append (std::unique_ptr< RNTupleModel > model, std::string_view ntupleName, TFile &file, const RNTupleWriteOptions &options=RNTupleWriteOptions())
	Throws an exception if the model is null.

static std::unique_ptr< RNTupleWriter >	Recreate (std::unique_ptr< RNTupleModel > model, std::string_view ntupleName, std::string_view storage, const RNTupleWriteOptions &options=RNTupleWriteOptions())
	Throws an exception if the model is null.

Private Member Functions
void	CommitClusterGroup ()

Private Attributes
NTupleSize_t	fLastCommitted = 0

NTupleSize_t	fLastCommittedClusterGroup = 0

std::size_t	fMaxUnzippedClusterSize
	Limit for committing cluster no matter the other tunables.

Detail::RNTupleMetrics	fMetrics

std::unique_ptr< RNTupleModel >	fModel
	Needs to be destructed before fSink.

std::uint64_t	fNBytesCommitted = 0
	The total number of bytes written to storage (i.e., after compression)

std::uint64_t	fNBytesFilled = 0
	The total number of bytes filled into all the so far committed clusters, i.e.

NTupleSize_t	fNEntries = 0

std::unique_ptr< Detail::RPageSink >	fSink

std::size_t	fUnzippedClusterSize = 0
	Keeps track of the number of bytes written into the current cluster.

NTupleSize_t	fUnzippedClusterSizeEst
	Estimator of uncompressed cluster size, taking into account the estimated compression ratio.

std::unique_ptr< Detail::RPageStorage::RTaskScheduler >	fZipTasks
	The page sink's parallel page compression scheduler if IMT is on.

#include <ROOT/RNTuple.hxx>

Constructor & Destructor Documentation

◆ RNTupleWriter() [1/2]

ROOT::Experimental::RNTupleWriter::RNTupleWriter	(	std::unique_ptr< RNTupleModel >	model,
		std::unique_ptr< Detail::RPageSink >	sink
	)

Throws an exception if the model or the sink is null.

Definition at line 265 of file RNTuple.cxx.

◆ RNTupleWriter() [2/2]

ROOT::Experimental::RNTupleWriter::RNTupleWriter ( const RNTupleWriter & )

delete

◆ ~RNTupleWriter()

ROOT::Experimental::RNTupleWriter::~RNTupleWriter ( )

Definition at line 292 of file RNTuple.cxx.

Member Function Documentation

◆ Append()

std::unique_ptr< ROOT::Experimental::RNTupleWriter > ROOT::Experimental::RNTupleWriter::Append	(	std::unique_ptr< RNTupleModel >	model,
		std::string_view	ntupleName,
		TFile &	file,
		const RNTupleWriteOptions &	options = `RNTupleWriteOptions()`
	)

static

Throws an exception if the model is null.

Definition at line 310 of file RNTuple.cxx.

◆ CommitCluster()

void ROOT::Experimental::RNTupleWriter::CommitCluster ( bool commitClusterGroup = false )

Ensure that the data from the so far seen Fill calls has been written to storage.

Definition at line 329 of file RNTuple.cxx.

◆ CommitClusterGroup()

void ROOT::Experimental::RNTupleWriter::CommitClusterGroup ( )

private

Definition at line 321 of file RNTuple.cxx.

◆ CreateEntry()

std::unique_ptr< REntry > ROOT::Experimental::RNTupleWriter::CreateEntry ( )

inline

Definition at line 427 of file RNTuple.hxx.

◆ CreateModelUpdater()

std::unique_ptr< RNTupleModel::RUpdater > ROOT::Experimental::RNTupleWriter::CreateModelUpdater ( )

inline

Get a RNTupleModel::RUpdater that provides limited support for incremental updates to the underlying model, e.g.

addition of new fields.

Example: add a new field after the model has been used to construct a RNTupleWriter object

#include <ROOT/RNTuple.hxx>
using ROOT::Experimental::RNTupleModel;
using ROOT::Experimental::RNTupleWriter;
 
auto model = RNTupleModel::Create();
auto fldFloat = model->MakeField<float>("fldFloat");
auto writer = RNTupleWriter::Recreate(std::move(model), "myNTuple", "some/file.root");
auto updater = writer->CreateModelUpdater();
updater->BeginUpdate();
updater->AddField(std::make_unique<RField<float>>("pt"));
updater->CommitUpdate();
 
// ...

Definition at line 453 of file RNTuple.hxx.

◆ EnableMetrics()

void ROOT::Experimental::RNTupleWriter::EnableMetrics ( )

inline

Definition at line 429 of file RNTuple.hxx.

◆ Fill() [1/2]

std::size_t ROOT::Experimental::RNTupleWriter::Fill ( )

inline

The simplest user interface if the default entry that comes with the ntuple model is used.

Returns: The number of uncompressed bytes written.

Definition at line 406 of file RNTuple.hxx.

◆ Fill() [2/2]

std::size_t ROOT::Experimental::RNTupleWriter::Fill ( REntry & entry )

inline

Multiple entries can have been instantiated from the ntuple model.

This method will perform a light check whether the entry comes from the ntuple's own model.

Returns: The number of uncompressed bytes written.

Definition at line 410 of file RNTuple.hxx.

◆ GetMetrics()

const Detail::RNTupleMetrics & ROOT::Experimental::RNTupleWriter::GetMetrics ( ) const

inline

Definition at line 430 of file RNTuple.hxx.

◆ GetModel()

const RNTupleModel * ROOT::Experimental::RNTupleWriter::GetModel ( ) const

inline

Definition at line 432 of file RNTuple.hxx.

◆ operator=()

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

delete

◆ Recreate()

std::unique_ptr< ROOT::Experimental::RNTupleWriter > ROOT::Experimental::RNTupleWriter::Recreate	(	std::unique_ptr< RNTupleModel >	model,
		std::string_view	ntupleName,
		std::string_view	storage,
		const RNTupleWriteOptions &	options = `RNTupleWriteOptions()`
	)

static

Throws an exception if the model is null.

Definition at line 303 of file RNTuple.cxx.

Member Data Documentation

◆ fLastCommitted

NTupleSize_t ROOT::Experimental::RNTupleWriter::fLastCommitted = 0

private

Definition at line 369 of file RNTuple.hxx.

◆ fLastCommittedClusterGroup

NTupleSize_t ROOT::Experimental::RNTupleWriter::fLastCommittedClusterGroup = 0

private

Definition at line 370 of file RNTuple.hxx.

◆ fMaxUnzippedClusterSize

std::size_t ROOT::Experimental::RNTupleWriter::fMaxUnzippedClusterSize

private

Limit for committing cluster no matter the other tunables.

Definition at line 380 of file RNTuple.hxx.

◆ fMetrics

Detail::RNTupleMetrics ROOT::Experimental::RNTupleWriter::fMetrics

private

Definition at line 368 of file RNTuple.hxx.

◆ fModel

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

private

Needs to be destructed before fSink.

Definition at line 367 of file RNTuple.hxx.

◆ fNBytesCommitted

std::uint64_t ROOT::Experimental::RNTupleWriter::fNBytesCommitted = 0

private

The total number of bytes written to storage (i.e., after compression)

Definition at line 375 of file RNTuple.hxx.

◆ fNBytesFilled

std::uint64_t ROOT::Experimental::RNTupleWriter::fNBytesFilled = 0

private

The total number of bytes filled into all the so far committed clusters, i.e.

the uncompressed size of the written clusters

Definition at line 378 of file RNTuple.hxx.

◆ fNEntries

NTupleSize_t ROOT::Experimental::RNTupleWriter::fNEntries = 0

private

Definition at line 371 of file RNTuple.hxx.

◆ fSink

std::unique_ptr<Detail::RPageSink> ROOT::Experimental::RNTupleWriter::fSink

private

Definition at line 365 of file RNTuple.hxx.

◆ fUnzippedClusterSize

std::size_t ROOT::Experimental::RNTupleWriter::fUnzippedClusterSize = 0

private

Keeps track of the number of bytes written into the current cluster.

Definition at line 373 of file RNTuple.hxx.

◆ fUnzippedClusterSizeEst

NTupleSize_t ROOT::Experimental::RNTupleWriter::fUnzippedClusterSizeEst

private

Estimator of uncompressed cluster size, taking into account the estimated compression ratio.

Definition at line 382 of file RNTuple.hxx.

◆ fZipTasks

std::unique_ptr<Detail::RPageStorage::RTaskScheduler> ROOT::Experimental::RNTupleWriter::fZipTasks

private

The page sink's parallel page compression scheduler if IMT is on.

Needs to be destructed after the page sink is destructed and so declared before.

Definition at line 364 of file RNTuple.hxx.

Libraries for ROOT::Experimental::RNTupleWriter:

[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

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Constructor & Destructor Documentation

◆ RNTupleWriter() [1/2]

◆ RNTupleWriter() [2/2]

◆ ~RNTupleWriter()

Member Function Documentation

◆ Append()

◆ CommitCluster()

◆ CommitClusterGroup()

◆ CreateEntry()

◆ CreateModelUpdater()

◆ EnableMetrics()

◆ Fill() [1/2]

◆ Fill() [2/2]

◆ GetMetrics()

◆ GetModel()

◆ operator=()

◆ Recreate()

Member Data Documentation

◆ fLastCommitted

◆ fLastCommittedClusterGroup

◆ fMaxUnzippedClusterSize

◆ fMetrics

◆ fModel

◆ fNBytesCommitted

◆ fNBytesFilled

◆ fNEntries

◆ fSink

◆ fUnzippedClusterSize

◆ fUnzippedClusterSizeEst

◆ fZipTasks