Abstract interface to read data from an ntuple.

The page source is initialized with the columns of interest. Pages from those columns can then be mapped into memory. The page source also gives access to the ntuple's meta-data.

Definition at line 159 of file RPageStorage.hxx.

Public Member Functions
	RPageSource (std::string_view ntupleName, const RNTupleReadOptions &fOptions)

virtual	~RPageSource ()

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

void	Attach ()
	Open the physical storage container for the tree. More...

virtual std::unique_ptr< RPageSource >	Clone () const =0
	Open the same storage multiple time, e.g. for reading in multiple threads. More...

ColumnId_t	GetColumnId (ColumnHandle_t columnHandle)

const RNTupleDescriptor &	GetDescriptor () const

NTupleSize_t	GetNElements (ColumnHandle_t columnHandle)

NTupleSize_t	GetNEntries ()

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

virtual RPage	PopulatePage (ColumnHandle_t columnHandle, const RClusterIndex &clusterIndex)=0
	Another version of PopulatePage that allows to specify cluster-relative indexes. More...

virtual RPage	PopulatePage (ColumnHandle_t columnHandle, NTupleSize_t globalIndex)=0
	Allocates and fills a page that contains the index-th element. More...

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

	RPageStorage (std::string_view name)

virtual	~RPageStorage ()

virtual ColumnHandle_t	AddColumn (DescriptorId_t fieldId, const RColumn &column)=0
	Register a new column. More...

virtual RNTupleMetrics &	GetMetrics ()=0
	Page storage implementations usually have their own metrics. More...

virtual EPageStorageType	GetType ()=0
	Whether the concrete implementation is a sink or a source. More...

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

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

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

Protected Member Functions
virtual RNTupleDescriptor	DoAttach ()=0

Protected Attributes
RNTupleDescriptor	fDescriptor

const RNTupleReadOptions	fOptions

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

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. More...

#include <ROOT/RPageStorage.hxx>

Inheritance diagram for ROOT::Experimental::Detail::RPageSource:

[legend]

Constructor & Destructor Documentation

◆ RPageSource()

ROOT::Experimental::Detail::RPageSource::RPageSource	(	std::string_view	ntupleName,
		const RNTupleReadOptions &	fOptions
	)

Definition at line 54 of file RPageStorage.cxx.

◆ ~RPageSource()

ROOT::Experimental::Detail::RPageSource::~RPageSource ( )

virtual

Definition at line 59 of file RPageStorage.cxx.

Member Function Documentation

◆ AddColumn()

ROOT::Experimental::Detail::RPageStorage::ColumnHandle_t ROOT::Experimental::Detail::RPageSource::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 72 of file RPageStorage.cxx.

◆ Attach()

void ROOT::Experimental::Detail::RPageSource::Attach ( )

inline

Open the physical storage container for the tree.

Definition at line 180 of file RPageStorage.hxx.

◆ Clone()

virtual std::unique_ptr< RPageSource > ROOT::Experimental::Detail::RPageSource::Clone ( ) const

pure virtual

Open the same storage multiple time, e.g. for reading in multiple threads.

Implemented in ROOT::Experimental::Detail::RPageSourceRaw, and ROOT::Experimental::Detail::RPageSourceRoot.

◆ Create()

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

static

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

Definition at line 63 of file RPageStorage.cxx.

◆ DoAttach()

virtual RNTupleDescriptor ROOT::Experimental::Detail::RPageSource::DoAttach ( )

protectedpure virtual

Implemented in ROOT::Experimental::Detail::RPageSourceRaw, and ROOT::Experimental::Detail::RPageSourceRoot.

◆ GetColumnId()

ROOT::Experimental::ColumnId_t ROOT::Experimental::Detail::RPageSource::GetColumnId ( ColumnHandle_t columnHandle )

Definition at line 90 of file RPageStorage.cxx.

◆ GetDescriptor()

const RNTupleDescriptor & ROOT::Experimental::Detail::RPageSource::GetDescriptor ( ) const

inline

Definition at line 176 of file RPageStorage.hxx.

◆ GetNElements()

ROOT::Experimental::NTupleSize_t ROOT::Experimental::Detail::RPageSource::GetNElements ( ColumnHandle_t columnHandle )

Definition at line 85 of file RPageStorage.cxx.

◆ GetNEntries()

ROOT::Experimental::NTupleSize_t ROOT::Experimental::Detail::RPageSource::GetNEntries ( )

Definition at line 80 of file RPageStorage.cxx.

◆ GetType()

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

inlinefinalvirtual

Whether the concrete implementation is a sink or a source.

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

Definition at line 175 of file RPageStorage.hxx.

◆ PopulatePage() [1/2]

virtual RPage ROOT::Experimental::Detail::RPageSource::PopulatePage	(	ColumnHandle_t	columnHandle,
		const RClusterIndex &	clusterIndex
	)

pure virtual

Another version of PopulatePage that allows to specify cluster-relative indexes.

Implemented in ROOT::Experimental::Detail::RPageSourceRaw, and ROOT::Experimental::Detail::RPageSourceRoot.

◆ PopulatePage() [2/2]

virtual RPage ROOT::Experimental::Detail::RPageSource::PopulatePage	(	ColumnHandle_t	columnHandle,
		NTupleSize_t	globalIndex
	)

pure virtual

Allocates and fills a page that contains the index-th element.

Implemented in ROOT::Experimental::Detail::RPageSourceRaw, and ROOT::Experimental::Detail::RPageSourceRoot.

Member Data Documentation

◆ fDescriptor

RNTupleDescriptor ROOT::Experimental::Detail::RPageSource::fDescriptor

protected

Definition at line 162 of file RPageStorage.hxx.

◆ fOptions

const RNTupleReadOptions ROOT::Experimental::Detail::RPageSource::fOptions

protected

Definition at line 161 of file RPageStorage.hxx.

Libraries for ROOT::Experimental::Detail::RPageSource:

[legend]

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ RPageSource()

◆ ~RPageSource()

Member Function Documentation

◆ AddColumn()

◆ Attach()

◆ Clone()

◆ Create()

◆ DoAttach()

◆ GetColumnId()

◆ GetDescriptor()

◆ GetNElements()

◆ GetNEntries()

◆ GetType()

◆ PopulatePage() [1/2]

◆ PopulatePage() [2/2]

Member Data Documentation

◆ fDescriptor

◆ fOptions