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 FlushCluster() or by destructing the writer. On I/O errors, an exception is thrown.

Definition at line 60 of file RNTupleWriter.hxx.

Public Member Functions
	RNTupleWriter (const RNTupleWriter &)=delete

	~RNTupleWriter ()

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

void	CommitDataset ()
	Closes the underlying file (page sink) and expires the model.

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.

void	FillNoFlush (REntry &entry, RNTupleFillStatus &status)
	Fill an entry into this ntuple, but don't commit the cluster.

void	FlushCluster ()
	Flush so far filled entries to storage.

void	FlushColumns ()
	Flush column data, preparing for CommitCluster or to reduce memory usage.

NTupleSize_t	GetLastCommitted () const
	Return the entry number that was last committed in a cluster.

NTupleSize_t	GetLastCommittedClusterGroup () const
	Return the entry number that was last committed in a cluster group.

NTupleSize_t	GetLastFlushed () const
	Return the entry number that was last flushed in a cluster.

const Detail::RNTupleMetrics &	GetMetrics () const

const RNTupleModel &	GetModel () const

NTupleSize_t	GetNEntries () const
	Return the number of entries filled so far.

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::initializer_list< std::pair< std::string_view, std::string_view > > fields, std::string_view ntupleName, std::string_view storage, const RNTupleWriteOptions &options=RNTupleWriteOptions())

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
	RNTupleWriter (std::unique_ptr< RNTupleModel > model, std::unique_ptr< Internal::RPageSink > sink)

void	CommitClusterGroup ()

Internal::RPageSink &	GetSink ()

RNTupleModel &	GetUpdatableModel ()

Static Private Member Functions
static std::unique_ptr< RNTupleWriter >	Create (std::unique_ptr< RNTupleModel > model, std::unique_ptr< Internal::RPageSink > sink, const RNTupleWriteOptions &options)
	Create a writer, potentially wrapping the sink in a RPageSinkBuf.

Private Attributes
RNTupleFillContext	fFillContext

NTupleSize_t	fLastCommittedClusterGroup = 0

Detail::RNTupleMetrics	fMetrics

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

Friends
std::unique_ptr< RNTupleWriter >	Internal::CreateRNTupleWriter (std::unique_ptr< RNTupleModel >, std::unique_ptr< Internal::RPageSink >)

#include <ROOT/RNTupleWriter.hxx>

Constructor & Destructor Documentation

◆ RNTupleWriter() [1/2]

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

private

Definition at line 33 of file RNTupleWriter.cxx.

◆ RNTupleWriter() [2/2]

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

delete

◆ ~RNTupleWriter()

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

Definition at line 48 of file RNTupleWriter.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 95 of file RNTupleWriter.cxx.

◆ CommitCluster()

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

inline

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

Definition at line 119 of file RNTupleWriter.hxx.

◆ CommitClusterGroup()

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

private

Definition at line 106 of file RNTupleWriter.cxx.

◆ CommitDataset()

void ROOT::Experimental::RNTupleWriter::CommitDataset ( )

Closes the underlying file (page sink) and expires the model.

Automatically called on destruct. Once the dataset is committed, calls to Fill(), [Commit|Flush]Cluster(), FlushColumns(), CreateEntry(), and model updating fail.

Definition at line 122 of file RNTupleWriter.cxx.

◆ Create()

std::unique_ptr< ROOT::Experimental::RNTupleWriter > ROOT::Experimental::RNTupleWriter::Create	(	std::unique_ptr< RNTupleModel >	model,
		std::unique_ptr< Internal::RPageSink >	sink,
		const RNTupleWriteOptions &	options
	)

staticprivate

Create a writer, potentially wrapping the sink in a RPageSinkBuf.

Definition at line 58 of file RNTupleWriter.cxx.

◆ CreateEntry()

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

inline

Definition at line 130 of file RNTupleWriter.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 165 of file RNTupleWriter.hxx.

◆ EnableMetrics()

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

inline

Definition at line 141 of file RNTupleWriter.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 105 of file RNTupleWriter.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 109 of file RNTupleWriter.hxx.

◆ FillNoFlush()

void ROOT::Experimental::RNTupleWriter::FillNoFlush	(	REntry &	entry,
		RNTupleFillStatus &	status
	)

inline

Fill an entry into this ntuple, but don't commit the cluster.

The calling code must pass an RNTupleFillStatus and check RNTupleFillStatus::ShouldFlushCluster.

Definition at line 112 of file RNTupleWriter.hxx.

◆ FlushCluster()

void ROOT::Experimental::RNTupleWriter::FlushCluster ( )

inline

Flush so far filled entries to storage.

Definition at line 117 of file RNTupleWriter.hxx.

◆ FlushColumns()

void ROOT::Experimental::RNTupleWriter::FlushColumns ( )

inline

Flush column data, preparing for CommitCluster or to reduce memory usage.

This will trigger compression of pages, but not actually write to storage (unless buffered writing is turned off).

Definition at line 115 of file RNTupleWriter.hxx.

◆ GetLastCommitted()

NTupleSize_t ROOT::Experimental::RNTupleWriter::GetLastCommitted ( ) const

inline

Return the entry number that was last committed in a cluster.

Definition at line 135 of file RNTupleWriter.hxx.

◆ GetLastCommittedClusterGroup()

NTupleSize_t ROOT::Experimental::RNTupleWriter::GetLastCommittedClusterGroup ( ) const

inline

Return the entry number that was last committed in a cluster group.

Definition at line 137 of file RNTupleWriter.hxx.

◆ GetLastFlushed()

NTupleSize_t ROOT::Experimental::RNTupleWriter::GetLastFlushed ( ) const

inline

Return the entry number that was last flushed in a cluster.

Definition at line 133 of file RNTupleWriter.hxx.

◆ GetMetrics()

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

inline

Definition at line 142 of file RNTupleWriter.hxx.

◆ GetModel()

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

inline

Definition at line 144 of file RNTupleWriter.hxx.

◆ GetNEntries()

NTupleSize_t ROOT::Experimental::RNTupleWriter::GetNEntries ( ) const

inline

Return the number of entries filled so far.

Definition at line 139 of file RNTupleWriter.hxx.

◆ GetSink()

Internal::RPageSink & ROOT::Experimental::RNTupleWriter::GetSink ( )

inlineprivate

Definition at line 77 of file RNTupleWriter.hxx.

◆ GetUpdatableModel()

ROOT::Experimental::RNTupleModel & ROOT::Experimental::RNTupleWriter::GetUpdatableModel ( )

private

Definition at line 114 of file RNTupleWriter.cxx.

◆ operator=()

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

delete

◆ Recreate() [1/2]

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

static

Definition at line 79 of file RNTupleWriter.cxx.

◆ Recreate() [2/2]

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 71 of file RNTupleWriter.cxx.

Friends And Related Symbol Documentation

◆ Internal::CreateRNTupleWriter

std::unique_ptr< RNTupleWriter > Internal::CreateRNTupleWriter	(	std::unique_ptr< RNTupleModel >	,
		std::unique_ptr< Internal::RPageSink >
	)

friend

Member Data Documentation

◆ fFillContext

RNTupleFillContext ROOT::Experimental::RNTupleWriter::fFillContext

private

Definition at line 69 of file RNTupleWriter.hxx.

◆ fLastCommittedClusterGroup

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

private

Definition at line 72 of file RNTupleWriter.hxx.

◆ fMetrics

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

private

Definition at line 70 of file RNTupleWriter.hxx.

◆ fZipTasks

std::unique_ptr<Internal::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 (in the fill context) is destructed and so declared before.

Definition at line 68 of file RNTupleWriter.hxx.

Libraries for ROOT::Experimental::RNTupleWriter:

[legend]

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

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

Public Member Functions

Static Public Member Functions

Private Member Functions

Static Private Member Functions

Private Attributes

Friends

Constructor & Destructor Documentation

◆ RNTupleWriter() [1/2]

◆ RNTupleWriter() [2/2]

◆ ~RNTupleWriter()

Member Function Documentation

◆ Append()

◆ CommitCluster()

◆ CommitClusterGroup()

◆ CommitDataset()

◆ Create()

◆ CreateEntry()

◆ CreateModelUpdater()

◆ EnableMetrics()

◆ Fill() [1/2]

◆ Fill() [2/2]

◆ FillNoFlush()

◆ FlushCluster()

◆ FlushColumns()

◆ GetLastCommitted()

◆ GetLastCommittedClusterGroup()

◆ GetLastFlushed()

◆ GetMetrics()

◆ GetModel()

◆ GetNEntries()

◆ GetSink()

◆ GetUpdatableModel()

◆ operator=()

◆ Recreate() [1/2]

◆ Recreate() [2/2]

Friends And Related Symbol Documentation

◆ Internal::CreateRNTupleWriter

Member Data Documentation

◆ fFillContext

◆ fLastCommittedClusterGroup

◆ fMetrics

◆ fZipTasks