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ROOT::Experimental::RNTupleDescriptor Class Reference

The on-storage meta-data of an ntuple.

Represents the on-disk (on storage) information about an ntuple. The meta-data consists of a header and one or several footers. The header carries the ntuple schema, i.e. the fields and the associated columns and their relationships. The footer(s) carry information about one or several clusters. For every cluster, a footer stores its location and size, and for every column the range of element indexes as well as a list of pages and page locations.

The descriptor provide machine-independent (de-)serialization of headers and footers, and it provides lookup routines for ntuple objects (pages, clusters, ...). It is supposed to be usable by all RPageStorage implementations.

The serialization does not use standard ROOT streamers in order to not let it depend on libCore. The serialization uses the concept of frames: header, footer, and substructures have a preamble with version numbers and the size of the writte struct. This allows for forward and backward compatibility when the meta-data evolves.

Definition at line 529 of file RNTupleDescriptor.hxx.

Classes

class  RClusterDescriptorIterable
 Used to loop over all the clusters of an ntuple (in unspecified order) More...
 
class  RClusterGroupDescriptorIterable
 Used to loop over all the cluster groups of an ntuple (in unspecified order) More...
 
class  RColumnDescriptorIterable
 Used to loop over a field's associated columns. More...
 
struct  RCreateModelOptions
 Modifiers passed to CreateModel More...
 
class  RExtraTypeInfoDescriptorIterable
 Used to loop over all the extra type info record of an ntuple (in unspecified order) More...
 
class  RFieldDescriptorIterable
 Used to loop over a field's child fields. More...
 
class  RHeaderExtension
 Summarizes information about fields and the corresponding columns that were added after the header has been serialized. More...
 

Public Member Functions

 RNTupleDescriptor ()=default
 
 RNTupleDescriptor (const RNTupleDescriptor &other)=delete
 
 RNTupleDescriptor (RNTupleDescriptor &&other)=default
 
RResult< void > AddClusterGroupDetails (DescriptorId_t clusterGroupId, std::vector< RClusterDescriptor > &clusterDescs)
 Methods to load and drop cluster group details (cluster IDs and page locations)
 
std::unique_ptr< RNTupleDescriptorClone () const
 
std::unique_ptr< RNTupleModelCreateModel (const RCreateModelOptions &options=RCreateModelOptions()) const
 Re-create the C++ model from the stored meta-data.
 
RResult< void > DropClusterGroupDetails (DescriptorId_t clusterGroupId)
 
DescriptorId_t FindClusterId (DescriptorId_t physicalColumnId, NTupleSize_t index) const
 
DescriptorId_t FindFieldId (std::string_view fieldName) const
 Searches for a top-level field.
 
DescriptorId_t FindFieldId (std::string_view fieldName, DescriptorId_t parentId) const
 
DescriptorId_t FindLogicalColumnId (DescriptorId_t fieldId, std::uint32_t columnIndex, std::uint16_t representationIndex) const
 
DescriptorId_t FindNextClusterId (DescriptorId_t clusterId) const
 
DescriptorId_t FindPhysicalColumnId (DescriptorId_t fieldId, std::uint32_t columnIndex, std::uint16_t representationIndex) const
 
DescriptorId_t FindPrevClusterId (DescriptorId_t clusterId) const
 
const RClusterDescriptorGetClusterDescriptor (DescriptorId_t clusterId) const
 
const RClusterGroupDescriptorGetClusterGroupDescriptor (DescriptorId_t clusterGroupId) const
 
RClusterGroupDescriptorIterable GetClusterGroupIterable () const
 
RClusterDescriptorIterable GetClusterIterable () const
 
const RColumnDescriptorGetColumnDescriptor (DescriptorId_t columnId) const
 
RColumnDescriptorIterable GetColumnIterable () const
 
RColumnDescriptorIterable GetColumnIterable (const RFieldDescriptor &fieldDesc) const
 
RColumnDescriptorIterable GetColumnIterable (DescriptorId_t fieldId) const
 
const std::string & GetDescription () const
 
RExtraTypeInfoDescriptorIterable GetExtraTypeInfoIterable () const
 
std::vector< std::uint64_t > GetFeatureFlags () const
 
const RFieldDescriptorGetFieldDescriptor (DescriptorId_t fieldId) const
 
RFieldDescriptorIterable GetFieldIterable (const RFieldDescriptor &fieldDesc) const
 
RFieldDescriptorIterable GetFieldIterable (const RFieldDescriptor &fieldDesc, const std::function< bool(DescriptorId_t, DescriptorId_t)> &comparator) const
 
RFieldDescriptorIterable GetFieldIterable (DescriptorId_t fieldId) const
 
RFieldDescriptorIterable GetFieldIterable (DescriptorId_t fieldId, const std::function< bool(DescriptorId_t, DescriptorId_t)> &comparator) const
 
const RFieldDescriptorGetFieldZero () const
 
DescriptorId_t GetFieldZeroId () const
 Returns the logical parent of all top-level NTuple data fields.
 
std::uint64_t GetGeneration () const
 
const RHeaderExtensionGetHeaderExtension () const
 Return header extension information; if the descriptor does not have a header extension, return nullptr
 
std::size_t GetNActiveClusters () const
 
const std::string & GetName () const
 
std::size_t GetNClusterGroups () const
 
std::size_t GetNClusters () const
 
NTupleSize_t GetNElements (DescriptorId_t physicalColumnId) const
 
NTupleSize_t GetNEntries () const
 We know the number of entries from adding the cluster summaries.
 
std::size_t GetNExtraTypeInfos () const
 
std::size_t GetNFields () const
 
std::size_t GetNLogicalColumns () const
 
std::size_t GetNPhysicalColumns () const
 
std::uint64_t GetOnDiskFooterSize () const
 
std::uint64_t GetOnDiskHeaderSize () const
 
std::uint64_t GetOnDiskHeaderXxHash3 () const
 
std::string GetQualifiedFieldName (DescriptorId_t fieldId) const
 Walks up the parents of the field ID and returns a field name of the form a.b.c.d In case of invalid field ID, an empty string is returned.
 
RFieldDescriptorIterable GetTopLevelFields () const
 
RFieldDescriptorIterable GetTopLevelFields (const std::function< bool(DescriptorId_t, DescriptorId_t)> &comparator) const
 
bool HasFeature (unsigned int flag) const
 
void IncGeneration ()
 
RNTupleDescriptoroperator= (const RNTupleDescriptor &other)=delete
 
RNTupleDescriptoroperator= (RNTupleDescriptor &&other)=default
 
bool operator== (const RNTupleDescriptor &other) const
 
void PrintInfo (std::ostream &output) const
 

Static Public Attributes

static constexpr unsigned int kFeatureFlagTest = 137
 

Private Attributes

std::unordered_map< DescriptorId_t, RClusterDescriptorfClusterDescriptors
 May contain only a subset of all the available clusters, e.g.
 
std::unordered_map< DescriptorId_t, RClusterGroupDescriptorfClusterGroupDescriptors
 
std::unordered_map< DescriptorId_t, RColumnDescriptorfColumnDescriptors
 
std::string fDescription
 Free text from the user.
 
std::vector< RExtraTypeInfoDescriptorfExtraTypeInfoDescriptors
 
std::set< unsigned intfFeatureFlags
 
std::unordered_map< DescriptorId_t, RFieldDescriptorfFieldDescriptors
 
DescriptorId_t fFieldZeroId = kInvalidDescriptorId
 Set by the descriptor builder.
 
std::uint64_t fGeneration = 0
 Once constructed by an RNTupleDescriptorBuilder, the descriptor is mostly immutable except for set of active the page locations.
 
std::unique_ptr< RHeaderExtensionfHeaderExtension
 
std::string fName
 The ntuple name needs to be unique in a given storage location (file)
 
std::uint64_t fNClusters = 0
 Updated by the descriptor builder when the cluster groups are added.
 
std::uint64_t fNEntries = 0
 Updated by the descriptor builder when the cluster groups are added.
 
std::uint64_t fNPhysicalColumns = 0
 Updated by the descriptor builder when columns are added.
 
std::uint64_t fOnDiskFooterSize = 0
 Like fOnDiskHeaderSize, contains both cluster summaries and page locations.
 
std::uint64_t fOnDiskHeaderSize = 0
 Set by the descriptor builder when deserialized.
 
std::uint64_t fOnDiskHeaderXxHash3 = 0
 Set by the descriptor builder when deserialized.
 

Friends

class Internal::RNTupleDescriptorBuilder
 

#include <ROOT/RNTupleDescriptor.hxx>

Constructor & Destructor Documentation

◆ RNTupleDescriptor() [1/3]

ROOT::Experimental::RNTupleDescriptor::RNTupleDescriptor ( )
default

◆ RNTupleDescriptor() [2/3]

ROOT::Experimental::RNTupleDescriptor::RNTupleDescriptor ( const RNTupleDescriptor other)
delete

◆ RNTupleDescriptor() [3/3]

ROOT::Experimental::RNTupleDescriptor::RNTupleDescriptor ( RNTupleDescriptor &&  other)
default

Member Function Documentation

◆ AddClusterGroupDetails()

ROOT::Experimental::RResult< void > ROOT::Experimental::RNTupleDescriptor::AddClusterGroupDetails ( DescriptorId_t  clusterGroupId,
std::vector< RClusterDescriptor > &  clusterDescs 
)

Methods to load and drop cluster group details (cluster IDs and page locations)

Definition at line 473 of file RNTupleDescriptor.cxx.

◆ Clone()

std::unique_ptr< ROOT::Experimental::RNTupleDescriptor > ROOT::Experimental::RNTupleDescriptor::Clone ( ) const

Definition at line 538 of file RNTupleDescriptor.cxx.

◆ CreateModel()

std::unique_ptr< ROOT::Experimental::RNTupleModel > ROOT::Experimental::RNTupleDescriptor::CreateModel ( const RCreateModelOptions options = RCreateModelOptions()) const

Re-create the C++ model from the stored meta-data.

Definition at line 514 of file RNTupleDescriptor.cxx.

◆ DropClusterGroupDetails()

ROOT::Experimental::RResult< void > ROOT::Experimental::RNTupleDescriptor::DropClusterGroupDetails ( DescriptorId_t  clusterGroupId)

Definition at line 499 of file RNTupleDescriptor.cxx.

◆ FindClusterId()

ROOT::Experimental::DescriptorId_t ROOT::Experimental::RNTupleDescriptor::FindClusterId ( DescriptorId_t  physicalColumnId,
NTupleSize_t  index 
) const

Definition at line 373 of file RNTupleDescriptor.cxx.

◆ FindFieldId() [1/2]

ROOT::Experimental::DescriptorId_t ROOT::Experimental::RNTupleDescriptor::FindFieldId ( std::string_view  fieldName) const

Searches for a top-level field.

Definition at line 342 of file RNTupleDescriptor.cxx.

◆ FindFieldId() [2/2]

ROOT::Experimental::DescriptorId_t ROOT::Experimental::RNTupleDescriptor::FindFieldId ( std::string_view  fieldName,
DescriptorId_t  parentId 
) const

Definition at line 311 of file RNTupleDescriptor.cxx.

◆ FindLogicalColumnId()

ROOT::Experimental::DescriptorId_t ROOT::Experimental::RNTupleDescriptor::FindLogicalColumnId ( DescriptorId_t  fieldId,
std::uint32_t  columnIndex,
std::uint16_t  representationIndex 
) const

Definition at line 348 of file RNTupleDescriptor.cxx.

◆ FindNextClusterId()

ROOT::Experimental::DescriptorId_t ROOT::Experimental::RNTupleDescriptor::FindNextClusterId ( DescriptorId_t  clusterId) const

Definition at line 388 of file RNTupleDescriptor.cxx.

◆ FindPhysicalColumnId()

ROOT::Experimental::DescriptorId_t ROOT::Experimental::RNTupleDescriptor::FindPhysicalColumnId ( DescriptorId_t  fieldId,
std::uint32_t  columnIndex,
std::uint16_t  representationIndex 
) const

Definition at line 363 of file RNTupleDescriptor.cxx.

◆ FindPrevClusterId()

ROOT::Experimental::DescriptorId_t ROOT::Experimental::RNTupleDescriptor::FindPrevClusterId ( DescriptorId_t  clusterId) const

Definition at line 402 of file RNTupleDescriptor.cxx.

◆ GetClusterDescriptor()

const RClusterDescriptor & ROOT::Experimental::RNTupleDescriptor::GetClusterDescriptor ( DescriptorId_t  clusterId) const
inline

Definition at line 616 of file RNTupleDescriptor.hxx.

◆ GetClusterGroupDescriptor()

const RClusterGroupDescriptor & ROOT::Experimental::RNTupleDescriptor::GetClusterGroupDescriptor ( DescriptorId_t  clusterGroupId) const
inline

Definition at line 612 of file RNTupleDescriptor.hxx.

◆ GetClusterGroupIterable()

ROOT::Experimental::RNTupleDescriptor::RClusterGroupDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetClusterGroupIterable ( ) const

Definition at line 1218 of file RNTupleDescriptor.cxx.

◆ GetClusterIterable()

ROOT::Experimental::RNTupleDescriptor::RClusterDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetClusterIterable ( ) const

Definition at line 1224 of file RNTupleDescriptor.cxx.

◆ GetColumnDescriptor()

const RColumnDescriptor & ROOT::Experimental::RNTupleDescriptor::GetColumnDescriptor ( DescriptorId_t  columnId) const
inline

Definition at line 608 of file RNTupleDescriptor.hxx.

◆ GetColumnIterable() [1/3]

ROOT::Experimental::RNTupleDescriptor::RColumnDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetColumnIterable ( ) const

Definition at line 1200 of file RNTupleDescriptor.cxx.

◆ GetColumnIterable() [2/3]

ROOT::Experimental::RNTupleDescriptor::RColumnDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetColumnIterable ( const RFieldDescriptor fieldDesc) const

Definition at line 1206 of file RNTupleDescriptor.cxx.

◆ GetColumnIterable() [3/3]

ROOT::Experimental::RNTupleDescriptor::RColumnDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetColumnIterable ( DescriptorId_t  fieldId) const

Definition at line 1212 of file RNTupleDescriptor.cxx.

◆ GetDescription()

const std::string & ROOT::Experimental::RNTupleDescriptor::GetDescription ( ) const
inline

Definition at line 645 of file RNTupleDescriptor.hxx.

◆ GetExtraTypeInfoIterable()

ROOT::Experimental::RNTupleDescriptor::RExtraTypeInfoDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetExtraTypeInfoIterable ( ) const

Definition at line 1230 of file RNTupleDescriptor.cxx.

◆ GetFeatureFlags()

std::vector< std::uint64_t > ROOT::Experimental::RNTupleDescriptor::GetFeatureFlags ( ) const

Definition at line 452 of file RNTupleDescriptor.cxx.

◆ GetFieldDescriptor()

const RFieldDescriptor & ROOT::Experimental::RNTupleDescriptor::GetFieldDescriptor ( DescriptorId_t  fieldId) const
inline

Definition at line 607 of file RNTupleDescriptor.hxx.

◆ GetFieldIterable() [1/4]

ROOT::Experimental::RNTupleDescriptor::RFieldDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetFieldIterable ( const RFieldDescriptor fieldDesc) const

Definition at line 1163 of file RNTupleDescriptor.cxx.

◆ GetFieldIterable() [2/4]

ROOT::Experimental::RNTupleDescriptor::RFieldDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetFieldIterable ( const RFieldDescriptor fieldDesc,
const std::function< bool(DescriptorId_t, DescriptorId_t)> &  comparator 
) const

Definition at line 1168 of file RNTupleDescriptor.cxx.

◆ GetFieldIterable() [3/4]

ROOT::Experimental::RNTupleDescriptor::RFieldDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetFieldIterable ( DescriptorId_t  fieldId) const

Definition at line 1175 of file RNTupleDescriptor.cxx.

◆ GetFieldIterable() [4/4]

ROOT::Experimental::RNTupleDescriptor::RFieldDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetFieldIterable ( DescriptorId_t  fieldId,
const std::function< bool(DescriptorId_t, DescriptorId_t)> &  comparator 
) const

Definition at line 1180 of file RNTupleDescriptor.cxx.

◆ GetFieldZero()

const RFieldDescriptor & ROOT::Experimental::RNTupleDescriptor::GetFieldZero ( ) const
inline

Definition at line 661 of file RNTupleDescriptor.hxx.

◆ GetFieldZeroId()

DescriptorId_t ROOT::Experimental::RNTupleDescriptor::GetFieldZeroId ( ) const
inline

Returns the logical parent of all top-level NTuple data fields.

Definition at line 660 of file RNTupleDescriptor.hxx.

◆ GetGeneration()

std::uint64_t ROOT::Experimental::RNTupleDescriptor::GetGeneration ( ) const
inline

Definition at line 687 of file RNTupleDescriptor.hxx.

◆ GetHeaderExtension()

const RHeaderExtension * ROOT::Experimental::RNTupleDescriptor::GetHeaderExtension ( ) const
inline

Return header extension information; if the descriptor does not have a header extension, return nullptr

Definition at line 681 of file RNTupleDescriptor.hxx.

◆ GetNActiveClusters()

std::size_t ROOT::Experimental::RNTupleDescriptor::GetNActiveClusters ( ) const
inline

Definition at line 652 of file RNTupleDescriptor.hxx.

◆ GetName()

const std::string & ROOT::Experimental::RNTupleDescriptor::GetName ( ) const
inline

Definition at line 644 of file RNTupleDescriptor.hxx.

◆ GetNClusterGroups()

std::size_t ROOT::Experimental::RNTupleDescriptor::GetNClusterGroups ( ) const
inline

Definition at line 650 of file RNTupleDescriptor.hxx.

◆ GetNClusters()

std::size_t ROOT::Experimental::RNTupleDescriptor::GetNClusters ( ) const
inline

Definition at line 651 of file RNTupleDescriptor.hxx.

◆ GetNElements()

ROOT::Experimental::NTupleSize_t ROOT::Experimental::RNTupleDescriptor::GetNElements ( DescriptorId_t  physicalColumnId) const

Definition at line 298 of file RNTupleDescriptor.cxx.

◆ GetNEntries()

NTupleSize_t ROOT::Experimental::RNTupleDescriptor::GetNEntries ( ) const
inline

We know the number of entries from adding the cluster summaries.

Definition at line 656 of file RNTupleDescriptor.hxx.

◆ GetNExtraTypeInfos()

std::size_t ROOT::Experimental::RNTupleDescriptor::GetNExtraTypeInfos ( ) const
inline

Definition at line 653 of file RNTupleDescriptor.hxx.

◆ GetNFields()

std::size_t ROOT::Experimental::RNTupleDescriptor::GetNFields ( ) const
inline

Definition at line 647 of file RNTupleDescriptor.hxx.

◆ GetNLogicalColumns()

std::size_t ROOT::Experimental::RNTupleDescriptor::GetNLogicalColumns ( ) const
inline

Definition at line 648 of file RNTupleDescriptor.hxx.

◆ GetNPhysicalColumns()

std::size_t ROOT::Experimental::RNTupleDescriptor::GetNPhysicalColumns ( ) const
inline

Definition at line 649 of file RNTupleDescriptor.hxx.

◆ GetOnDiskFooterSize()

std::uint64_t ROOT::Experimental::RNTupleDescriptor::GetOnDiskFooterSize ( ) const
inline

Definition at line 605 of file RNTupleDescriptor.hxx.

◆ GetOnDiskHeaderSize()

std::uint64_t ROOT::Experimental::RNTupleDescriptor::GetOnDiskHeaderSize ( ) const
inline

Definition at line 604 of file RNTupleDescriptor.hxx.

◆ GetOnDiskHeaderXxHash3()

std::uint64_t ROOT::Experimental::RNTupleDescriptor::GetOnDiskHeaderXxHash3 ( ) const
inline

Definition at line 603 of file RNTupleDescriptor.hxx.

◆ GetQualifiedFieldName()

std::string ROOT::Experimental::RNTupleDescriptor::GetQualifiedFieldName ( DescriptorId_t  fieldId) const

Walks up the parents of the field ID and returns a field name of the form a.b.c.d In case of invalid field ID, an empty string is returned.

Definition at line 330 of file RNTupleDescriptor.cxx.

◆ GetTopLevelFields() [1/2]

ROOT::Experimental::RNTupleDescriptor::RFieldDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetTopLevelFields ( ) const

Definition at line 1187 of file RNTupleDescriptor.cxx.

◆ GetTopLevelFields() [2/2]

ROOT::Experimental::RNTupleDescriptor::RFieldDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetTopLevelFields ( const std::function< bool(DescriptorId_t, DescriptorId_t)> &  comparator) const

Definition at line 1193 of file RNTupleDescriptor.cxx.

◆ HasFeature()

bool ROOT::Experimental::RNTupleDescriptor::HasFeature ( unsigned int  flag) const
inline

Definition at line 677 of file RNTupleDescriptor.hxx.

◆ IncGeneration()

void ROOT::Experimental::RNTupleDescriptor::IncGeneration ( )
inline

Definition at line 688 of file RNTupleDescriptor.hxx.

◆ operator=() [1/2]

RNTupleDescriptor & ROOT::Experimental::RNTupleDescriptor::operator= ( const RNTupleDescriptor other)
delete

◆ operator=() [2/2]

RNTupleDescriptor & ROOT::Experimental::RNTupleDescriptor::operator= ( RNTupleDescriptor &&  other)
default

◆ operator==()

bool ROOT::Experimental::RNTupleDescriptor::operator== ( const RNTupleDescriptor other) const

Definition at line 282 of file RNTupleDescriptor.cxx.

◆ PrintInfo()

void ROOT::Experimental::RNTupleDescriptor::PrintInfo ( std::ostream &  output) const

Definition at line 83 of file RNTupleDescriptorFmt.cxx.

Friends And Related Symbol Documentation

◆ Internal::RNTupleDescriptorBuilder

Definition at line 530 of file RNTupleDescriptor.hxx.

Member Data Documentation

◆ fClusterDescriptors

std::unordered_map<DescriptorId_t, RClusterDescriptor> ROOT::Experimental::RNTupleDescriptor::fClusterDescriptors
private

May contain only a subset of all the available clusters, e.g.

the clusters of the current file from a chain of files

Definition at line 566 of file RNTupleDescriptor.hxx.

◆ fClusterGroupDescriptors

std::unordered_map<DescriptorId_t, RClusterGroupDescriptor> ROOT::Experimental::RNTupleDescriptor::fClusterGroupDescriptors
private

Definition at line 563 of file RNTupleDescriptor.hxx.

◆ fColumnDescriptors

std::unordered_map<DescriptorId_t, RColumnDescriptor> ROOT::Experimental::RNTupleDescriptor::fColumnDescriptors
private

Definition at line 562 of file RNTupleDescriptor.hxx.

◆ fDescription

std::string ROOT::Experimental::RNTupleDescriptor::fDescription
private

Free text from the user.

Definition at line 539 of file RNTupleDescriptor.hxx.

◆ fExtraTypeInfoDescriptors

std::vector<RExtraTypeInfoDescriptor> ROOT::Experimental::RNTupleDescriptor::fExtraTypeInfoDescriptors
private

Definition at line 567 of file RNTupleDescriptor.hxx.

◆ fFeatureFlags

std::set<unsigned int> ROOT::Experimental::RNTupleDescriptor::fFeatureFlags
private

Definition at line 560 of file RNTupleDescriptor.hxx.

◆ fFieldDescriptors

std::unordered_map<DescriptorId_t, RFieldDescriptor> ROOT::Experimental::RNTupleDescriptor::fFieldDescriptors
private

Definition at line 561 of file RNTupleDescriptor.hxx.

◆ fFieldZeroId

DescriptorId_t ROOT::Experimental::RNTupleDescriptor::fFieldZeroId = kInvalidDescriptorId
private

Set by the descriptor builder.

Definition at line 549 of file RNTupleDescriptor.hxx.

◆ fGeneration

std::uint64_t ROOT::Experimental::RNTupleDescriptor::fGeneration = 0
private

Once constructed by an RNTupleDescriptorBuilder, the descriptor is mostly immutable except for set of active the page locations.

During the lifetime of the descriptor, page location information for clusters can be added or removed. When this happens, the generation should be increased, so that users of the descriptor know that the information changed. The generation is increased, e.g., by the page source's exclusive lock guard around the descriptor. It is used, e.g., by the descriptor cache in RNTupleReader.

Definition at line 558 of file RNTupleDescriptor.hxx.

◆ fHeaderExtension

std::unique_ptr<RHeaderExtension> ROOT::Experimental::RNTupleDescriptor::fHeaderExtension
private

Definition at line 568 of file RNTupleDescriptor.hxx.

◆ fName

std::string ROOT::Experimental::RNTupleDescriptor::fName
private

The ntuple name needs to be unique in a given storage location (file)

Definition at line 537 of file RNTupleDescriptor.hxx.

◆ fNClusters

std::uint64_t ROOT::Experimental::RNTupleDescriptor::fNClusters = 0
private

Updated by the descriptor builder when the cluster groups are added.

Definition at line 546 of file RNTupleDescriptor.hxx.

◆ fNEntries

std::uint64_t ROOT::Experimental::RNTupleDescriptor::fNEntries = 0
private

Updated by the descriptor builder when the cluster groups are added.

Definition at line 545 of file RNTupleDescriptor.hxx.

◆ fNPhysicalColumns

std::uint64_t ROOT::Experimental::RNTupleDescriptor::fNPhysicalColumns = 0
private

Updated by the descriptor builder when columns are added.

Definition at line 547 of file RNTupleDescriptor.hxx.

◆ fOnDiskFooterSize

std::uint64_t ROOT::Experimental::RNTupleDescriptor::fOnDiskFooterSize = 0
private

Like fOnDiskHeaderSize, contains both cluster summaries and page locations.

Definition at line 543 of file RNTupleDescriptor.hxx.

◆ fOnDiskHeaderSize

std::uint64_t ROOT::Experimental::RNTupleDescriptor::fOnDiskHeaderSize = 0
private

Set by the descriptor builder when deserialized.

Definition at line 542 of file RNTupleDescriptor.hxx.

◆ fOnDiskHeaderXxHash3

std::uint64_t ROOT::Experimental::RNTupleDescriptor::fOnDiskHeaderXxHash3 = 0
private

Set by the descriptor builder when deserialized.

Definition at line 541 of file RNTupleDescriptor.hxx.

◆ kFeatureFlagTest

constexpr unsigned int ROOT::Experimental::RNTupleDescriptor::kFeatureFlagTest = 137
staticconstexpr

Definition at line 571 of file RNTupleDescriptor.hxx.

Libraries for ROOT::Experimental::RNTupleDescriptor:

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