Abstract interface to write data into an ntuple.

The page sink takes the list of columns and afterwards a series of page commits and cluster commits. The user is responsible to commit clusters at a consistent point, i.e. when all pages corresponding to data up to the given entry number are committed.

Definition at line 169 of file RPageStorage.hxx.

Classes
struct	RCounters
	Default I/O performance counters that get registered in fMetrics. More...

Public Member Functions
	RPageSink (const RPageSink &)=delete

	RPageSink (RPageSink &&)=default

	RPageSink (std::string_view ntupleName, const RNTupleWriteOptions &options)

	~RPageSink () override

ColumnHandle_t	AddColumn (DescriptorId_t fieldId, const RColumn &column) final
	Register a new column.

std::uint64_t	CommitCluster (NTupleSize_t nEntries)
	Finalize the current cluster and create a new one for the following data.

void	CommitClusterGroup ()
	Write out the page locations (page list envelope) for all the committed clusters since the last call of CommitClusterGroup (or the beginning of writing).

void	CommitDataset ()
	Finalize the current cluster and the entrire data set.

void	CommitPage (ColumnHandle_t columnHandle, const RPage &page)
	Write a page to the storage. The column must have been added before.

void	CommitSealedPage (DescriptorId_t columnId, const RPageStorage::RSealedPage &sealedPage)
	Write a preprocessed page to storage. The column must have been added before.

void	CommitSealedPageV (std::span< RPageStorage::RSealedPageGroup > ranges)
	Write a vector of preprocessed pages to storage. The corresponding columns must have been added before.

void	Create (RNTupleModel &model)
	Physically creates the storage container to hold the ntuple (e.g., a keys a TFile or an S3 bucket) To do so, Create() calls CreateImpl() after updating the descriptor.

void	DropColumn (ColumnHandle_t) final
	Unregisters a column.

RNTupleMetrics &	GetMetrics () override
	Returns the default metrics object. Subclasses might alternatively provide their own metrics object by overriding this.

EPageStorageType	GetType () final
	Whether the concrete implementation is a sink or a source.

const RNTupleWriteOptions &	GetWriteOptions () const
	Returns the sink's write options.

RPageSink &	operator= (const RPageSink &)=delete

RPageSink &	operator= (RPageSink &&)=default

virtual RPage	ReservePage (ColumnHandle_t columnHandle, std::size_t nElements)=0
	Get a new, empty page for the given column that can be filled with up to nElements.

Public Member Functions inherited from ROOT::Experimental::Detail::RPageStorage
	RPageStorage (const RPageStorage &other)=delete

	RPageStorage (RPageStorage &&other)=default

	RPageStorage (std::string_view name)

virtual	~RPageStorage ()

const std::string &	GetNTupleName () const
	Returns the NTuple name.

RPageStorage &	operator= (const RPageStorage &other)=delete

RPageStorage &	operator= (RPageStorage &&other)=default

virtual void	ReleasePage (RPage &page)=0
	Every page store needs to be able to free pages it handed out.

void	SetTaskScheduler (RTaskScheduler *taskScheduler)

Static Public Member Functions
static std::unique_ptr< RPageSink >	Create (std::string_view ntupleName, std::string_view location, const RNTupleWriteOptions &options=RNTupleWriteOptions())
	Guess the concrete derived page source from the file name (location)

Protected Member Functions
virtual RNTupleLocator	CommitClusterGroupImpl (unsigned char *serializedPageList, std::uint32_t length)=0
	Returns the locator of the page list envelope of the given buffer that contains the serialized page list.

virtual std::uint64_t	CommitClusterImpl (NTupleSize_t nEntries)=0
	Returns the number of bytes written to storage (excluding metadata)

virtual void	CommitDatasetImpl (unsigned char *serializedFooter, std::uint32_t length)=0

virtual RNTupleLocator	CommitPageImpl (ColumnHandle_t columnHandle, const RPage &page)=0

virtual RNTupleLocator	CommitSealedPageImpl (DescriptorId_t columnId, const RPageStorage::RSealedPage &sealedPage)=0

virtual std::vector< RNTupleLocator >	CommitSealedPageVImpl (std::span< RPageStorage::RSealedPageGroup > ranges)
	Vector commit of preprocessed pages.

virtual void	CreateImpl (const RNTupleModel &model, unsigned char *serializedHeader, std::uint32_t length)=0

void	EnableDefaultMetrics (const std::string &prefix)
	Enables the default set of metrics provided by RPageSink.

RSealedPage	SealPage (const RPage &page, const RColumnElementBase &element, int compressionSetting)
	Helper for streaming a page.

Static Protected Member Functions
static RSealedPage	SealPage (const RPage &page, const RColumnElementBase &element, int compressionSetting, void *buf)
	Seal a page using the provided buffer.

Protected Attributes
std::unique_ptr< RNTupleCompressor >	fCompressor
	Helper to zip pages and header/footer; includes a 16MB (kMAXZIPBUF) zip buffer.

std::unique_ptr< RCounters >	fCounters

RNTupleDescriptorBuilder	fDescriptorBuilder

RNTupleMetrics	fMetrics

std::uint64_t	fNextClusterInGroup = 0
	Remembers the starting cluster id for the next cluster group.

std::vector< RClusterDescriptor::RColumnRange >	fOpenColumnRanges
	Keeps track of the number of elements in the currently open cluster. Indexed by column id.

std::vector< RClusterDescriptor::RPageRange >	fOpenPageRanges
	Keeps track of the written pages in the currently open cluster. Indexed by column id.

std::unique_ptr< RNTupleWriteOptions >	fOptions

NTupleSize_t	fPrevClusterNEntries = 0
	Used to calculate the number of entries in the current cluster.

Protected Attributes inherited from ROOT::Experimental::Detail::RPageStorage
std::string	fNTupleName

RTaskScheduler *	fTaskScheduler = nullptr

Private Attributes
Internal::RNTupleSerializer::RContext	fSerializationContext
	Used to map the IDs of the descriptor to the physical IDs issued during header/footer serialization.

Additional Inherited Members
Public Types inherited from ROOT::Experimental::Detail::RPageStorage
using	ColumnHandle_t = RColumnHandle
	The column handle identifies a column with the current open page storage.

using	SealedPageSequence_t = std::deque< RSealedPage >

#include <ROOT/RPageStorage.hxx>

Inheritance diagram for ROOT::Experimental::Detail::RPageSink:

[legend]

Constructor & Destructor Documentation

◆ RPageSink() [1/3]

ROOT::Experimental::Detail::RPageSink::RPageSink	(	std::string_view	ntupleName,
		const RNTupleWriteOptions &	options
	)

Definition at line 237 of file RPageStorage.cxx.

◆ RPageSink() [2/3]

ROOT::Experimental::Detail::RPageSink::RPageSink ( const RPageSink & )

delete

◆ RPageSink() [3/3]

ROOT::Experimental::Detail::RPageSink::RPageSink ( RPageSink && )

default

◆ ~RPageSink()

ROOT::Experimental::Detail::RPageSink::~RPageSink ( )

override

Definition at line 242 of file RPageStorage.cxx.

Member Function Documentation

◆ AddColumn()

ROOT::Experimental::Detail::RPageStorage::ColumnHandle_t ROOT::Experimental::Detail::RPageSink::AddColumn	(	DescriptorId_t	fieldId,
		const RColumn &	column
	)

finalvirtual

Register a new column.

When reading, the column must exist in the ntuple on disk corresponding to the meta-data. When writing, every column can only be attached once.

Implements ROOT::Experimental::Detail::RPageStorage.

Definition at line 272 of file RPageStorage.cxx.

◆ CommitCluster()

std::uint64_t ROOT::Experimental::Detail::RPageSink::CommitCluster ( NTupleSize_t nEntries )

Finalize the current cluster and create a new one for the following data.

Returns the number of bytes written to storage (excluding meta-data).

Definition at line 368 of file RPageStorage.cxx.

◆ CommitClusterGroup()

void ROOT::Experimental::Detail::RPageSink::CommitClusterGroup ( )

Write out the page locations (page list envelope) for all the committed clusters since the last call of CommitClusterGroup (or the beginning of writing).

Definition at line 390 of file RPageStorage.cxx.

◆ CommitClusterGroupImpl()

virtual RNTupleLocator ROOT::Experimental::Detail::RPageSink::CommitClusterGroupImpl	(	unsigned char *	serializedPageList,
		std::uint32_t	length
	)

protectedpure virtual

Returns the locator of the page list envelope of the given buffer that contains the serialized page list.

Typically, the implementation takes care of compressing and writing the provided buffer.

Implemented in ROOT::Experimental::Detail::RPageSinkBuf, ROOT::Experimental::Detail::RPageSinkDaos, and ROOT::Experimental::Detail::RPageSinkFile.

◆ CommitClusterImpl()

virtual std::uint64_t ROOT::Experimental::Detail::RPageSink::CommitClusterImpl ( NTupleSize_t nEntries )

protectedpure virtual

Returns the number of bytes written to storage (excluding metadata)

Implemented in ROOT::Experimental::Detail::RPageSinkBuf, ROOT::Experimental::Detail::RPageSinkDaos, and ROOT::Experimental::Detail::RPageSinkFile.

◆ CommitDataset()

void ROOT::Experimental::Detail::RPageSink::CommitDataset ( )

Finalize the current cluster and the entrire data set.

Definition at line 419 of file RPageStorage.cxx.

◆ CommitDatasetImpl()

virtual void ROOT::Experimental::Detail::RPageSink::CommitDatasetImpl	(	unsigned char *	serializedFooter,
		std::uint32_t	length
	)

protectedpure virtual

Implemented in ROOT::Experimental::Detail::RPageSinkBuf, ROOT::Experimental::Detail::RPageSinkDaos, and ROOT::Experimental::Detail::RPageSinkFile.

◆ CommitPage()

void ROOT::Experimental::Detail::RPageSink::CommitPage	(	ColumnHandle_t	columnHandle,
		const RPage &	page
	)

Write a page to the storage. The column must have been added before.

Definition at line 317 of file RPageStorage.cxx.

◆ CommitPageImpl()

virtual RNTupleLocator ROOT::Experimental::Detail::RPageSink::CommitPageImpl	(	ColumnHandle_t	columnHandle,
		const RPage &	page
	)

protectedpure virtual

Implemented in ROOT::Experimental::Detail::RPageSinkBuf, ROOT::Experimental::Detail::RPageSinkDaos, and ROOT::Experimental::Detail::RPageSinkFile.

◆ CommitSealedPage()

void ROOT::Experimental::Detail::RPageSink::CommitSealedPage	(	DescriptorId_t	columnId,
		const RPageStorage::RSealedPage &	sealedPage
	)

Write a preprocessed page to storage. The column must have been added before.

Definition at line 328 of file RPageStorage.cxx.

◆ CommitSealedPageImpl()

virtual RNTupleLocator ROOT::Experimental::Detail::RPageSink::CommitSealedPageImpl	(	DescriptorId_t	columnId,
		const RPageStorage::RSealedPage &	sealedPage
	)

protectedpure virtual

Implemented in ROOT::Experimental::Detail::RPageSinkDaos, ROOT::Experimental::Detail::RPageSinkFile, and ROOT::Experimental::Detail::RPageSinkBuf.

◆ CommitSealedPageV()

void ROOT::Experimental::Detail::RPageSink::CommitSealedPageV ( std::span< RPageStorage::RSealedPageGroup > ranges )

Write a vector of preprocessed pages to storage. The corresponding columns must have been added before.

Definition at line 351 of file RPageStorage.cxx.

◆ CommitSealedPageVImpl()

std::vector< ROOT::Experimental::RNTupleLocator > ROOT::Experimental::Detail::RPageSink::CommitSealedPageVImpl ( std::span< RPageStorage::RSealedPageGroup > ranges )

protectedvirtual

Vector commit of preprocessed pages.

The ranges array specifies a range of sealed pages to be committed for each column. The returned vector contains, in order, the RNTupleLocator for each page on each range in ranges, i.e. the first N entries refer to the N pages in ranges[0], followed by M entries that refer to the M pages in ranges[1], etc. The default is to call CommitSealedPageImpl for each page; derived classes may provide an optimized implementation though.

Reimplemented in ROOT::Experimental::Detail::RPageSinkDaos.

Definition at line 341 of file RPageStorage.cxx.

◆ Create() [1/2]

void ROOT::Experimental::Detail::RPageSink::Create ( RNTupleModel & model )

Physically creates the storage container to hold the ntuple (e.g., a keys a TFile or an S3 bucket) To do so, Create() calls CreateImpl() after updating the descriptor.

Create() associates column handles to the columns referenced by the model

Definition at line 280 of file RPageStorage.cxx.

◆ Create() [2/2]

std::unique_ptr< ROOT::Experimental::Detail::RPageSink > ROOT::Experimental::Detail::RPageSink::Create	(	std::string_view	ntupleName,
		std::string_view	location,
		const RNTupleWriteOptions &	options = `RNTupleWriteOptions()`
	)

static

Guess the concrete derived page source from the file name (location)

Definition at line 246 of file RPageStorage.cxx.

◆ CreateImpl()

virtual void ROOT::Experimental::Detail::RPageSink::CreateImpl	(	const RNTupleModel &	model,
		unsigned char *	serializedHeader,
		std::uint32_t	length
	)

protectedpure virtual

Implemented in ROOT::Experimental::Detail::RPageSinkBuf, ROOT::Experimental::Detail::RPageSinkDaos, and ROOT::Experimental::Detail::RPageSinkFile.

◆ DropColumn()

void ROOT::Experimental::Detail::RPageSink::DropColumn ( ColumnHandle_t columnHandle )

inlinefinalvirtual

Unregisters a column.

A page source decreases the reference counter for the corresponding active column. For a page sink, dropping columns is currently a no-op.

Implements ROOT::Experimental::Detail::RPageStorage.

Definition at line 262 of file RPageStorage.hxx.

◆ EnableDefaultMetrics()

void ROOT::Experimental::Detail::RPageSink::EnableDefaultMetrics ( const std::string & prefix )

protected

Enables the default set of metrics provided by RPageSink.

prefix will be used as the prefix for the counters registered in the internal RNTupleMetrics object. This set of counters can be extended by a subclass by calling fMetrics.MakeCounter<...>().

A subclass using the default set of metrics is always responsible for updating the counters appropriately, e.g. fCounters->fNPageCommited.Inc()

Alternatively, a subclass might provide its own RNTupleMetrics object by overriding the GetMetrics() member function.

Definition at line 467 of file RPageStorage.cxx.

◆ GetMetrics()

RNTupleMetrics & ROOT::Experimental::Detail::RPageSink::GetMetrics ( )

inlineoverridevirtual

Returns the default metrics object. Subclasses might alternatively provide their own metrics object by overriding this.

Implements ROOT::Experimental::Detail::RPageStorage.

Reimplemented in ROOT::Experimental::Detail::RPageSinkBuf.

Definition at line 288 of file RPageStorage.hxx.

◆ GetType()

EPageStorageType ROOT::Experimental::Detail::RPageSink::GetType ( )

inlinefinalvirtual

Whether the concrete implementation is a sink or a source.

Implements ROOT::Experimental::Detail::RPageStorage.

Definition at line 257 of file RPageStorage.hxx.

◆ GetWriteOptions()

const RNTupleWriteOptions & ROOT::Experimental::Detail::RPageSink::GetWriteOptions ( ) const

inline

Returns the sink's write options.

Definition at line 259 of file RPageStorage.hxx.

◆ operator=() [1/2]

RPageSink & ROOT::Experimental::Detail::RPageSink::operator= ( const RPageSink & )

delete

◆ operator=() [2/2]

RPageSink & ROOT::Experimental::Detail::RPageSink::operator= ( RPageSink && )

default

◆ ReservePage()

virtual RPage ROOT::Experimental::Detail::RPageSink::ReservePage	(	ColumnHandle_t	columnHandle,
		std::size_t	nElements
	)

pure virtual

Get a new, empty page for the given column that can be filled with up to nElements.

If nElements is zero, the page sink picks an appropriate size.

Implemented in ROOT::Experimental::Detail::RPageSinkBuf, ROOT::Experimental::Detail::RPageSinkDaos, and ROOT::Experimental::Detail::RPageSinkFile.

◆ SealPage() [1/2]

ROOT::Experimental::Detail::RPageStorage::RSealedPage ROOT::Experimental::Detail::RPageSink::SealPage	(	const RPage &	page,
		const RColumnElementBase &	element,
		int	compressionSetting
	)

protected

Helper for streaming a page.

This is commonly used in derived, concrete page sinks. Note that if compressionSetting is 0 (uncompressed) and the page is mappable, the returned sealed page will point directly to the input page buffer. Otherwise, the sealed page references an internal buffer of fCompressor. Thus, the buffer pointed to by the RSealedPage should never be freed. Usage of this method requires construction of fCompressor.

Definition at line 460 of file RPageStorage.cxx.

◆ SealPage() [2/2]

ROOT::Experimental::Detail::RPageStorage::RSealedPage ROOT::Experimental::Detail::RPageSink::SealPage	(	const RPage &	page,
		const RColumnElementBase &	element,
		int	compressionSetting,
		void *	buf
	)

staticprotected

Seal a page using the provided buffer.

Definition at line 431 of file RPageStorage.cxx.

Member Data Documentation

◆ fCompressor

std::unique_ptr<RNTupleCompressor> ROOT::Experimental::Detail::RPageSink::fCompressor

protected

Helper to zip pages and header/footer; includes a 16MB (kMAXZIPBUF) zip buffer.

There could be concrete page sinks that don't need a compressor. Therefore, and in order to stay consistent with the page source, we leave it up to the derived class whether or not the compressor gets constructed.

Definition at line 193 of file RPageStorage.hxx.

◆ fCounters

std::unique_ptr<RCounters> ROOT::Experimental::Detail::RPageSink::fCounters

protected

Definition at line 185 of file RPageStorage.hxx.

◆ fDescriptorBuilder

RNTupleDescriptorBuilder ROOT::Experimental::Detail::RPageSink::fDescriptorBuilder

protected

Definition at line 203 of file RPageStorage.hxx.

◆ fMetrics

RNTupleMetrics ROOT::Experimental::Detail::RPageSink::fMetrics

protected

Definition at line 186 of file RPageStorage.hxx.

◆ fNextClusterInGroup

std::uint64_t ROOT::Experimental::Detail::RPageSink::fNextClusterInGroup = 0

protected

Remembers the starting cluster id for the next cluster group.

Definition at line 196 of file RPageStorage.hxx.

◆ fOpenColumnRanges

std::vector<RClusterDescriptor::RColumnRange> ROOT::Experimental::Detail::RPageSink::fOpenColumnRanges

protected

Keeps track of the number of elements in the currently open cluster. Indexed by column id.

Definition at line 200 of file RPageStorage.hxx.

◆ fOpenPageRanges

std::vector<RClusterDescriptor::RPageRange> ROOT::Experimental::Detail::RPageSink::fOpenPageRanges

protected

Keeps track of the written pages in the currently open cluster. Indexed by column id.

Definition at line 202 of file RPageStorage.hxx.

◆ fOptions

std::unique_ptr<RNTupleWriteOptions> ROOT::Experimental::Detail::RPageSink::fOptions

protected

Definition at line 188 of file RPageStorage.hxx.

◆ fPrevClusterNEntries

NTupleSize_t ROOT::Experimental::Detail::RPageSink::fPrevClusterNEntries = 0

protected

Used to calculate the number of entries in the current cluster.

Definition at line 198 of file RPageStorage.hxx.

◆ fSerializationContext

Internal::RNTupleSerializer::RContext ROOT::Experimental::Detail::RPageSink::fSerializationContext

private

Used to map the IDs of the descriptor to the physical IDs issued during header/footer serialization.

Definition at line 172 of file RPageStorage.hxx.

Libraries for ROOT::Experimental::Detail::RPageSink:

[legend]

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

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

Classes

Public Member Functions

Static Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Private Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ RPageSink() [1/3]

◆ RPageSink() [2/3]

◆ RPageSink() [3/3]

◆ ~RPageSink()

Member Function Documentation

◆ AddColumn()

◆ CommitCluster()

◆ CommitClusterGroup()

◆ CommitClusterGroupImpl()

◆ CommitClusterImpl()

◆ CommitDataset()

◆ CommitDatasetImpl()

◆ CommitPage()

◆ CommitPageImpl()

◆ CommitSealedPage()

◆ CommitSealedPageImpl()

◆ CommitSealedPageV()

◆ CommitSealedPageVImpl()

◆ Create() [1/2]

◆ Create() [2/2]

◆ CreateImpl()

◆ DropColumn()

◆ EnableDefaultMetrics()

◆ GetMetrics()

◆ GetType()

◆ GetWriteOptions()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ ReservePage()

◆ SealPage() [1/2]

◆ SealPage() [2/2]

Member Data Documentation

◆ fCompressor

◆ fCounters

◆ fDescriptorBuilder

◆ fMetrics

◆ fNextClusterInGroup

◆ fOpenColumnRanges

◆ fOpenPageRanges

◆ fOptions

◆ fPrevClusterNEntries

◆ fSerializationContext