Builds an index on one or several fields of an RNTuple so it can be joined onto other RNTuples.

Definition at line 36 of file RNTupleIndex.hxx.

Classes
class	RIndexValue
	Container for the hashes of the indexed fields. More...

struct	RIndexValueHash
	Hash combinining the individual index value hashes from RIndexValue. More...

Public Types
using	NTupleIndexValue_t = std::uint64_t

Public Member Functions
	RNTupleIndex (const RNTupleIndex &other)=delete

	RNTupleIndex (RNTupleIndex &&other)=delete

	~RNTupleIndex ()=default

void	Build ()
	Build the index.

const std::vector< NTupleSize_t > *	GetAllEntryNumbers (const std::vector< void * > &valuePtrs) const
	Get all entry numbers for the given index.

template<typename... Ts>
const std::vector< NTupleSize_t > *	GetAllEntryNumbers (Ts... values) const
	Get all entry numbers for the given index.

NTupleSize_t	GetFirstEntryNumber (const std::vector< void * > &valuePtrs) const
	Get the first entry number containing the given index value.

template<typename... Ts>
NTupleSize_t	GetFirstEntryNumber (Ts... values) const
	Get the entry number containing the given index value.

std::size_t	GetSize () const
	Get the number of indexed values.

bool	IsBuilt () const
	Whether the index has been built (and therefore ready to be used).

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

RNTupleIndex &	operator= (RNTupleIndex &&other)=delete

Static Public Member Functions
static std::unique_ptr< RNTupleIndex >	Create (const std::vector< std::string > &fieldNames, const RPageSource &pageSource, bool deferBuild=false)
	Create an RNTupleIndex from an existing RNTuple.

Private Member Functions
	RNTupleIndex (const std::vector< std::string > &fieldNames, const RPageSource &pageSource)
	Create an a new RNTupleIndex for the RNTuple represented by the provided page source.

void	EnsureBuilt () const
	Ensure the RNTupleIndex has been built.

Private Attributes
std::unordered_map< RIndexValue, std::vector< NTupleSize_t >, RIndexValueHash >	fIndex
	The index itself.

std::vector< std::unique_ptr< RFieldBase > >	fIndexFields
	The fields for which the index is built. Used to compute the hashes for each entry value.

bool	fIsBuilt = false
	Only built indexes can be queried.

std::unique_ptr< RPageSource >	fPageSource
	The page source belonging to the RNTuple for which to build the index.

#include <ROOT/RNTupleIndex.hxx>

Member Typedef Documentation

◆ NTupleIndexValue_t

using ROOT::Experimental::Internal::RNTupleIndex::NTupleIndexValue_t = std::uint64_t

Definition at line 38 of file RNTupleIndex.hxx.

Constructor & Destructor Documentation

◆ RNTupleIndex() [1/3]

ROOT::Experimental::Internal::RNTupleIndex::RNTupleIndex	(	const std::vector< std::string > &	fieldNames,
		const RPageSource &	pageSource
	)

private

Create an a new RNTupleIndex for the RNTuple represented by the provided page source.

Parameters

[in]	fieldNames	The names of the fields to index. Only integral-type fields can be specified as index fields.
[in]	pageSource	The page source.

Definition at line 36 of file RNTupleIndex.cxx.

◆ RNTupleIndex() [2/3]

ROOT::Experimental::Internal::RNTupleIndex::RNTupleIndex ( const RNTupleIndex & other )

delete

◆ RNTupleIndex() [3/3]

ROOT::Experimental::Internal::RNTupleIndex::RNTupleIndex ( RNTupleIndex && other )

delete

◆ ~RNTupleIndex()

ROOT::Experimental::Internal::RNTupleIndex::~RNTupleIndex ( )

default

Member Function Documentation

◆ Build()

void ROOT::Experimental::Internal::RNTupleIndex::Build ( )

Build the index.

Only a built index can be queried (with RNTupleIndex::GetFirstEntryNumber or RNTupleIndex::GetAllEntryNumbers).

Definition at line 78 of file RNTupleIndex.cxx.

◆ Create()

std::unique_ptr< ROOT::Experimental::Internal::RNTupleIndex > ROOT::Experimental::Internal::RNTupleIndex::Create	(	const std::vector< std::string > &	fieldNames,
		const RPageSource &	pageSource,
		bool	deferBuild = `false`
	)

static

Create an RNTupleIndex from an existing RNTuple.

Parameters

[in]	fieldNames	The names of the fields to index. Only integral-type fields can be specified as index fields.
[in]	pageSource	The page source.
[in]	deferBuild	When set to `true`, an empty index will be created. A call to RNTupleIndex::Build is required before the index can actually be used.

Returns: A pointer to the newly-created index.

Definition at line 67 of file RNTupleIndex.cxx.

◆ EnsureBuilt()

void ROOT::Experimental::Internal::RNTupleIndex::EnsureBuilt ( ) const

private

Ensure the RNTupleIndex has been built.

Exceptions

RException If the index has not been built, and can therefore not be used yet.

Definition at line 60 of file RNTupleIndex.cxx.

◆ GetAllEntryNumbers() [1/2]

const std::vector< ROOT::Experimental::NTupleSize_t > * ROOT::Experimental::Internal::RNTupleIndex::GetAllEntryNumbers ( const std::vector< void * > & valuePtrs ) const

Get all entry numbers for the given index.

Parameters

[in] valuePtrs A vector of pointers to the index values to look up.

Returns: The entry numbers that corresponds to valuePtrs. When no such entry exists, an empty vector is returned.

Definition at line 126 of file RNTupleIndex.cxx.

◆ GetAllEntryNumbers() [2/2]

template<typename... Ts>

const std::vector< NTupleSize_t > * ROOT::Experimental::Internal::RNTupleIndex::GetAllEntryNumbers ( Ts... values ) const

inline

Get all entry numbers for the given index.

See also: GetAllEntryNumbers(std::vector<void *> valuePtrs)

Definition at line 186 of file RNTupleIndex.hxx.

◆ GetFirstEntryNumber() [1/2]

ROOT::Experimental::NTupleSize_t ROOT::Experimental::Internal::RNTupleIndex::GetFirstEntryNumber ( const std::vector< void * > & valuePtrs ) const

Get the first entry number containing the given index value.

Parameters

[in] valuePtrs A vector of pointers to the index values to look up.

Returns: The first entry number that corresponds to valuePtrs. When no such entry exists, kInvalidNTupleIndex is returned.

Note that in case multiple entries corresponding to the provided index value exist, the first occurrence is returned. Use RNTupleIndex::GetAllEntryNumbers to get all entries.

Definition at line 117 of file RNTupleIndex.cxx.

◆ GetFirstEntryNumber() [2/2]

template<typename... Ts>

NTupleSize_t ROOT::Experimental::Internal::RNTupleIndex::GetFirstEntryNumber ( Ts... values ) const

inline

Get the entry number containing the given index value.

See also: GetFirstEntryNumber(std::vector<void *> valuePtrs)

Definition at line 160 of file RNTupleIndex.hxx.

◆ GetSize()

std::size_t ROOT::Experimental::Internal::RNTupleIndex::GetSize ( ) const

inline

Get the number of indexed values.

Returns: The number of indexed values.

Note: This does not have to correspond to the number of entries in the original RNTuple. If the original RNTuple contains duplicate index values, they are counted as one.

Definition at line 129 of file RNTupleIndex.hxx.

◆ IsBuilt()

bool ROOT::Experimental::Internal::RNTupleIndex::IsBuilt ( ) const

inline

Whether the index has been built (and therefore ready to be used).

Returns: true if the index has been built.

Only built indexes can be queried.

Definition at line 141 of file RNTupleIndex.hxx.

◆ operator=() [1/2]

RNTupleIndex & ROOT::Experimental::Internal::RNTupleIndex::operator= ( const RNTupleIndex & other )

delete

◆ operator=() [2/2]

RNTupleIndex & ROOT::Experimental::Internal::RNTupleIndex::operator= ( RNTupleIndex && other )

delete

Member Data Documentation

◆ fIndex

std::unordered_map<RIndexValue, std::vector<NTupleSize_t>, RIndexValueHash> ROOT::Experimental::Internal::RNTupleIndex::fIndex

private

The index itself.

Maps field values (or combinations thereof in case the index is defined for multiple fields) to their respsective entry numbers.

Definition at line 71 of file RNTupleIndex.hxx.

◆ fIndexFields

std::vector<std::unique_ptr<RFieldBase> > ROOT::Experimental::Internal::RNTupleIndex::fIndexFields

private

The fields for which the index is built. Used to compute the hashes for each entry value.

Definition at line 77 of file RNTupleIndex.hxx.

◆ fIsBuilt

bool ROOT::Experimental::Internal::RNTupleIndex::fIsBuilt = false

private

Only built indexes can be queried.

Definition at line 80 of file RNTupleIndex.hxx.

◆ fPageSource

std::unique_ptr<RPageSource> ROOT::Experimental::Internal::RNTupleIndex::fPageSource

private

The page source belonging to the RNTuple for which to build the index.

Definition at line 74 of file RNTupleIndex.hxx.

Libraries for ROOT::Experimental::Internal::RNTupleIndex:

[legend]

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

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

Classes

Public Types

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Member Typedef Documentation

◆ NTupleIndexValue_t

Constructor & Destructor Documentation

◆ RNTupleIndex() [1/3]

◆ RNTupleIndex() [2/3]

◆ RNTupleIndex() [3/3]

◆ ~RNTupleIndex()

Member Function Documentation

◆ Build()

◆ Create()

◆ EnsureBuilt()

◆ GetAllEntryNumbers() [1/2]

◆ GetAllEntryNumbers() [2/2]

◆ GetFirstEntryNumber() [1/2]

◆ GetFirstEntryNumber() [2/2]

◆ GetSize()

◆ IsBuilt()

◆ operator=() [1/2]

◆ operator=() [2/2]

Member Data Documentation

◆ fIndex

◆ fIndexFields

◆ fIsBuilt

◆ fPageSource