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 619 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... | |
Static Public Attributes | |
static constexpr unsigned int | kFeatureFlagTest = 137 |
Private Member Functions | |
RNTupleDescriptor | CloneSchema () const |
Creates a descriptor containing only the schema information about this RNTuple, i.e. | |
ROOT::DescriptorId_t | FindClusterId (ROOT::NTupleSize_t entryIdx) const |
Private Attributes | |
std::unordered_map< ROOT::DescriptorId_t, RClusterDescriptor > | fClusterDescriptors |
May contain only a subset of all the available clusters, e.g. | |
std::unordered_map< ROOT::DescriptorId_t, RClusterGroupDescriptor > | fClusterGroupDescriptors |
std::unordered_map< ROOT::DescriptorId_t, RColumnDescriptor > | fColumnDescriptors |
std::string | fDescription |
Free text from the user. | |
std::vector< RExtraTypeInfoDescriptor > | fExtraTypeInfoDescriptors |
std::set< unsigned int > | fFeatureFlags |
std::unordered_map< ROOT::DescriptorId_t, RFieldDescriptor > | fFieldDescriptors |
ROOT::DescriptorId_t | fFieldZeroId = ROOT::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< RHeaderExtension > | fHeaderExtension |
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. | |
std::vector< ROOT::DescriptorId_t > | fSortedClusterGroupIds |
References cluster groups sorted by entry range and thus allows for binary search. | |
Friends | |
RNTupleDescriptor | Internal::CloneDescriptorSchema (const RNTupleDescriptor &desc) |
class | Internal::RNTupleDescriptorBuilder |
#include <ROOT/RNTupleDescriptor.hxx>
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ROOT::RResult< void > ROOT::Experimental::RNTupleDescriptor::AddClusterGroupDetails | ( | ROOT::DescriptorId_t | clusterGroupId, |
std::vector< RClusterDescriptor > & | clusterDescs ) |
Methods to load and drop cluster group details (cluster IDs and page locations)
Definition at line 599 of file RNTupleDescriptor.cxx.
ROOT::Experimental::RNTupleDescriptor ROOT::Experimental::RNTupleDescriptor::Clone | ( | ) | const |
Definition at line 693 of file RNTupleDescriptor.cxx.
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Creates a descriptor containing only the schema information about this RNTuple, i.e.
all the information needed to create a new RNTuple with the same schema as this one but not necessarily the same clustering. This is used when merging two RNTuples.
Definition at line 668 of file RNTupleDescriptor.cxx.
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 642 of file RNTupleDescriptor.cxx.
ROOT::RResult< void > ROOT::Experimental::RNTupleDescriptor::DropClusterGroupDetails | ( | ROOT::DescriptorId_t | clusterGroupId | ) |
Definition at line 627 of file RNTupleDescriptor.cxx.
ROOT::DescriptorId_t ROOT::Experimental::RNTupleDescriptor::FindClusterId | ( | ROOT::DescriptorId_t | physicalColumnId, |
ROOT::NTupleSize_t | index ) const |
Definition at line 401 of file RNTupleDescriptor.cxx.
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Definition at line 464 of file RNTupleDescriptor.cxx.
ROOT::DescriptorId_t ROOT::Experimental::RNTupleDescriptor::FindFieldId | ( | std::string_view | fieldName | ) | const |
Searches for a top-level field.
Definition at line 371 of file RNTupleDescriptor.cxx.
ROOT::DescriptorId_t ROOT::Experimental::RNTupleDescriptor::FindFieldId | ( | std::string_view | fieldName, |
ROOT::DescriptorId_t | parentId ) const |
Definition at line 340 of file RNTupleDescriptor.cxx.
ROOT::DescriptorId_t ROOT::Experimental::RNTupleDescriptor::FindLogicalColumnId | ( | ROOT::DescriptorId_t | fieldId, |
std::uint32_t | columnIndex, | ||
std::uint16_t | representationIndex ) const |
Definition at line 376 of file RNTupleDescriptor.cxx.
ROOT::DescriptorId_t ROOT::Experimental::RNTupleDescriptor::FindNextClusterId | ( | ROOT::DescriptorId_t | clusterId | ) | const |
Definition at line 516 of file RNTupleDescriptor.cxx.
ROOT::DescriptorId_t ROOT::Experimental::RNTupleDescriptor::FindPhysicalColumnId | ( | ROOT::DescriptorId_t | fieldId, |
std::uint32_t | columnIndex, | ||
std::uint16_t | representationIndex ) const |
Definition at line 392 of file RNTupleDescriptor.cxx.
ROOT::DescriptorId_t ROOT::Experimental::RNTupleDescriptor::FindPrevClusterId | ( | ROOT::DescriptorId_t | clusterId | ) | const |
Definition at line 527 of file RNTupleDescriptor.cxx.
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Definition at line 746 of file RNTupleDescriptor.hxx.
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Definition at line 742 of file RNTupleDescriptor.hxx.
ROOT::Experimental::RNTupleDescriptor::RClusterGroupDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetClusterGroupIterable | ( | ) | const |
Definition at line 1392 of file RNTupleDescriptor.cxx.
ROOT::Experimental::RNTupleDescriptor::RClusterDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetClusterIterable | ( | ) | const |
Definition at line 1398 of file RNTupleDescriptor.cxx.
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Definition at line 738 of file RNTupleDescriptor.hxx.
ROOT::Experimental::RNTupleDescriptor::RColumnDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetColumnIterable | ( | ) | const |
Definition at line 1374 of file RNTupleDescriptor.cxx.
ROOT::Experimental::RNTupleDescriptor::RColumnDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetColumnIterable | ( | const RFieldDescriptor & | fieldDesc | ) | const |
Definition at line 1380 of file RNTupleDescriptor.cxx.
ROOT::Experimental::RNTupleDescriptor::RColumnDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetColumnIterable | ( | ROOT::DescriptorId_t | fieldId | ) | const |
Definition at line 1386 of file RNTupleDescriptor.cxx.
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Definition at line 775 of file RNTupleDescriptor.hxx.
ROOT::Experimental::RNTupleDescriptor::RExtraTypeInfoDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetExtraTypeInfoIterable | ( | ) | const |
Definition at line 1404 of file RNTupleDescriptor.cxx.
std::vector< std::uint64_t > ROOT::Experimental::RNTupleDescriptor::GetFeatureFlags | ( | ) | const |
Definition at line 578 of file RNTupleDescriptor.cxx.
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Definition at line 734 of file RNTupleDescriptor.hxx.
ROOT::Experimental::RNTupleDescriptor::RFieldDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetFieldIterable | ( | const RFieldDescriptor & | fieldDesc | ) | const |
Definition at line 1335 of file RNTupleDescriptor.cxx.
ROOT::Experimental::RNTupleDescriptor::RFieldDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetFieldIterable | ( | const RFieldDescriptor & | fieldDesc, |
const std::function< bool(ROOT::DescriptorId_t, ROOT::DescriptorId_t)> & | comparator ) const |
Definition at line 1340 of file RNTupleDescriptor.cxx.
ROOT::Experimental::RNTupleDescriptor::RFieldDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetFieldIterable | ( | ROOT::DescriptorId_t | fieldId | ) | const |
Definition at line 1348 of file RNTupleDescriptor.cxx.
ROOT::Experimental::RNTupleDescriptor::RFieldDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetFieldIterable | ( | ROOT::DescriptorId_t | fieldId, |
const std::function< bool(ROOT::DescriptorId_t, ROOT::DescriptorId_t)> & | comparator ) const |
Definition at line 1353 of file RNTupleDescriptor.cxx.
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Definition at line 791 of file RNTupleDescriptor.hxx.
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Returns the logical parent of all top-level NTuple data fields.
Definition at line 790 of file RNTupleDescriptor.hxx.
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Definition at line 818 of file RNTupleDescriptor.hxx.
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Return header extension information; if the descriptor does not have a header extension, return nullptr
Definition at line 811 of file RNTupleDescriptor.hxx.
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Definition at line 782 of file RNTupleDescriptor.hxx.
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Definition at line 774 of file RNTupleDescriptor.hxx.
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Definition at line 780 of file RNTupleDescriptor.hxx.
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Definition at line 781 of file RNTupleDescriptor.hxx.
ROOT::NTupleSize_t ROOT::Experimental::RNTupleDescriptor::GetNElements | ( | ROOT::DescriptorId_t | physicalColumnId | ) | const |
Definition at line 327 of file RNTupleDescriptor.cxx.
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We know the number of entries from adding the cluster summaries.
Definition at line 786 of file RNTupleDescriptor.hxx.
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Definition at line 783 of file RNTupleDescriptor.hxx.
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Definition at line 777 of file RNTupleDescriptor.hxx.
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Definition at line 778 of file RNTupleDescriptor.hxx.
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Definition at line 779 of file RNTupleDescriptor.hxx.
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Definition at line 732 of file RNTupleDescriptor.hxx.
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Definition at line 731 of file RNTupleDescriptor.hxx.
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Definition at line 730 of file RNTupleDescriptor.hxx.
std::string ROOT::Experimental::RNTupleDescriptor::GetQualifiedFieldName | ( | ROOT::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 359 of file RNTupleDescriptor.cxx.
ROOT::Experimental::RNTupleDescriptor::RFieldDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetTopLevelFields | ( | ) | const |
Definition at line 1361 of file RNTupleDescriptor.cxx.
ROOT::Experimental::RNTupleDescriptor::RFieldDescriptorIterable ROOT::Experimental::RNTupleDescriptor::GetTopLevelFields | ( | const std::function< bool(ROOT::DescriptorId_t, ROOT::DescriptorId_t)> & | comparator | ) | const |
Definition at line 1367 of file RNTupleDescriptor.cxx.
Definition at line 807 of file RNTupleDescriptor.hxx.
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Definition at line 819 of file RNTupleDescriptor.hxx.
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bool ROOT::Experimental::RNTupleDescriptor::operator== | ( | const RNTupleDescriptor & | other | ) | const |
Definition at line 312 of file RNTupleDescriptor.cxx.
void ROOT::Experimental::RNTupleDescriptor::PrintInfo | ( | std::ostream & | output | ) | const |
Definition at line 81 of file RNTupleDescriptorFmt.cxx.
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Definition at line 620 of file RNTupleDescriptor.hxx.
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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 669 of file RNTupleDescriptor.hxx.
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Definition at line 662 of file RNTupleDescriptor.hxx.
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Definition at line 638 of file RNTupleDescriptor.hxx.
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Free text from the user.
Definition at line 630 of file RNTupleDescriptor.hxx.
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Definition at line 640 of file RNTupleDescriptor.hxx.
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Definition at line 636 of file RNTupleDescriptor.hxx.
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Definition at line 637 of file RNTupleDescriptor.hxx.
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Set by the descriptor builder.
Definition at line 632 of file RNTupleDescriptor.hxx.
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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 660 of file RNTupleDescriptor.hxx.
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Definition at line 641 of file RNTupleDescriptor.hxx.
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The ntuple name needs to be unique in a given storage location (file)
Definition at line 628 of file RNTupleDescriptor.hxx.
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Updated by the descriptor builder when the cluster groups are added.
Definition at line 651 of file RNTupleDescriptor.hxx.
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Updated by the descriptor builder when the cluster groups are added.
Definition at line 650 of file RNTupleDescriptor.hxx.
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Updated by the descriptor builder when columns are added.
Definition at line 634 of file RNTupleDescriptor.hxx.
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Like fOnDiskHeaderSize, contains both cluster summaries and page locations.
Definition at line 648 of file RNTupleDescriptor.hxx.
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Set by the descriptor builder when deserialized.
Definition at line 646 of file RNTupleDescriptor.hxx.
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Set by the descriptor builder when deserialized.
Definition at line 647 of file RNTupleDescriptor.hxx.
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References cluster groups sorted by entry range and thus allows for binary search.
Note that this list is empty during the descriptor building process and will only be created when the final descriptor is extracted from the builder.
Definition at line 666 of file RNTupleDescriptor.hxx.
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Definition at line 680 of file RNTupleDescriptor.hxx.