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ROOT::Experimental::Internal::RColumn Class Reference

A column is a storage-backed array of a simple, fixed-size type, from which pages can be mapped into memory.

Definition at line 43 of file RColumn.hxx.

Public Member Functions

 RColumn (const RColumn &)=delete
 
 ~RColumn ()
 
void Append (const void *from)
 
void AppendV (const void *from, std::size_t count)
 
void ConnectPageSink (DescriptorId_t fieldId, RPageSink &pageSink, NTupleSize_t firstElementIndex=0U)
 Connect the column to a page sink.
 
void ConnectPageSource (DescriptorId_t fieldId, RPageSource &pageSource)
 Connect the column to a page source.
 
void Flush ()
 
RClusterIndex GetClusterIndex (NTupleSize_t globalIndex)
 
void GetCollectionInfo (const NTupleSize_t globalIndex, RClusterIndex *collectionStart, ClusterSize_t *collectionSize)
 For offset columns only, look at the two adjacent values that define a collection's coordinates.
 
void GetCollectionInfo (RClusterIndex clusterIndex, RClusterIndex *collectionStart, ClusterSize_t *collectionSize)
 
ColumnId_t GetColumnIdSource () const
 
RColumnElementBaseGetElement () const
 
NTupleSize_t GetFirstElementIndex () const
 
NTupleSize_t GetGlobalIndex (RClusterIndex clusterIndex)
 
RPageStorage::ColumnHandle_t GetHandleSink () const
 
RPageStorage::ColumnHandle_t GetHandleSource () const
 
std::uint32_t GetIndex () const
 
const RColumnModelGetModel () const
 
NTupleSize_t GetNElements () const
 
RPageSinkGetPageSink () const
 
RPageSourceGetPageSource () const
 
void GetSwitchInfo (NTupleSize_t globalIndex, RClusterIndex *varIndex, std::uint32_t *tag)
 Get the currently active cluster id.
 
template<typename CppT >
CppT * Map (const NTupleSize_t globalIndex)
 
template<typename CppT >
CppT * Map (RClusterIndex clusterIndex)
 
void MapPage (const NTupleSize_t index)
 
void MapPage (RClusterIndex clusterIndex)
 
template<typename CppT >
CppT * MapV (const NTupleSize_t globalIndex, NTupleSize_t &nItems)
 
template<typename CppT >
CppT * MapV (RClusterIndex clusterIndex, NTupleSize_t &nItems)
 
RColumnoperator= (const RColumn &)=delete
 
void Read (const NTupleSize_t globalIndex, void *to)
 
void Read (RClusterIndex clusterIndex, void *to)
 
void ReadV (const NTupleSize_t globalIndex, const ClusterSize_t::ValueType count, void *to)
 
void ReadV (RClusterIndex clusterIndex, const ClusterSize_t::ValueType count, void *to)
 

Static Public Member Functions

template<typename CppT >
static std::unique_ptr< RColumnCreate (const RColumnModel &model, std::uint32_t index)
 

Private Member Functions

 RColumn (const RColumnModel &model, std::uint32_t index)
 
void FlushShadowWritePage ()
 When the main write page surpasses the 50% fill level, the (full) shadow write page gets flushed.
 
void HandleWritePageIfFull ()
 Used in Append() and AppendV() to handle the case when the main page reached the target size.
 

Private Attributes

std::uint32_t fApproxNElementsPerPage = 0
 For writing, the targeted number of elements, given by fApproxNElementsPerPage (in the write options) and the element size.
 
ColumnId_t fColumnIdSource = kInvalidColumnId
 The column id is used to find matching pages with content when reading.
 
std::unique_ptr< RColumnElementBasefElement
 Used to pack and unpack pages on writing/reading.
 
NTupleSize_t fFirstElementIndex = 0
 Global index of the first element in this column; usually == 0, unless it is a deferred column.
 
RPageStorage::ColumnHandle_t fHandleSink
 
RPageStorage::ColumnHandle_t fHandleSource
 
std::uint32_t fIndex
 Columns belonging to the same field are distinguished by their order.
 
RColumnModel fModel
 
NTupleSize_t fNElements = 0
 The number of elements written resp. available in the column.
 
RPageSinkfPageSink = nullptr
 
RPageSourcefPageSource = nullptr
 
RPage fReadPage
 The currently mapped page for reading.
 
RPage fWritePage [2]
 A set of open pages into which new elements are being written.
 
int fWritePageIdx = 0
 Index of the current write page.
 

#include <ROOT/RColumn.hxx>

Constructor & Destructor Documentation

◆ RColumn() [1/2]

ROOT::Experimental::Internal::RColumn::RColumn ( const RColumnModel model,
std::uint32_t  index 
)
private

Definition at line 23 of file RColumn.cxx.

◆ RColumn() [2/2]

ROOT::Experimental::Internal::RColumn::RColumn ( const RColumn )
delete

◆ ~RColumn()

ROOT::Experimental::Internal::RColumn::~RColumn ( )

Definition at line 28 of file RColumn.cxx.

Member Function Documentation

◆ Append()

void ROOT::Experimental::Internal::RColumn::Append ( const void *  from)
inline

Definition at line 133 of file RColumn.hxx.

◆ AppendV()

void ROOT::Experimental::Internal::RColumn::AppendV ( const void *  from,
std::size_t  count 
)
inline

Definition at line 147 of file RColumn.hxx.

◆ ConnectPageSink()

void ROOT::Experimental::Internal::RColumn::ConnectPageSink ( DescriptorId_t  fieldId,
RPageSink pageSink,
NTupleSize_t  firstElementIndex = 0U 
)

Connect the column to a page sink.

firstElementIndex can be used to specify the first column element index with backing storage for this column. On read back, elements before firstElementIndex will cause the zero page to be mapped.

Definition at line 42 of file RColumn.cxx.

◆ ConnectPageSource()

void ROOT::Experimental::Internal::RColumn::ConnectPageSource ( DescriptorId_t  fieldId,
RPageSource pageSource 
)

Connect the column to a page source.

Definition at line 63 of file RColumn.cxx.

◆ Create()

template<typename CppT >
static std::unique_ptr< RColumn > ROOT::Experimental::Internal::RColumn::Create ( const RColumnModel model,
std::uint32_t  index 
)
inlinestatic

Definition at line 115 of file RColumn.hxx.

◆ Flush()

void ROOT::Experimental::Internal::RColumn::Flush ( )

Definition at line 75 of file RColumn.cxx.

◆ FlushShadowWritePage()

void ROOT::Experimental::Internal::RColumn::FlushShadowWritePage ( )
inlineprivate

When the main write page surpasses the 50% fill level, the (full) shadow write page gets flushed.

Definition at line 103 of file RColumn.hxx.

◆ GetClusterIndex()

RClusterIndex ROOT::Experimental::Internal::RColumn::GetClusterIndex ( NTupleSize_t  globalIndex)
inline

Definition at line 284 of file RColumn.hxx.

◆ GetCollectionInfo() [1/2]

void ROOT::Experimental::Internal::RColumn::GetCollectionInfo ( const NTupleSize_t  globalIndex,
RClusterIndex collectionStart,
ClusterSize_t collectionSize 
)
inline

For offset columns only, look at the two adjacent values that define a collection's coordinates.

Definition at line 293 of file RColumn.hxx.

◆ GetCollectionInfo() [2/2]

void ROOT::Experimental::Internal::RColumn::GetCollectionInfo ( RClusterIndex  clusterIndex,
RClusterIndex collectionStart,
ClusterSize_t collectionSize 
)
inline

Definition at line 316 of file RColumn.hxx.

◆ GetColumnIdSource()

ColumnId_t ROOT::Experimental::Internal::RColumn::GetColumnIdSource ( ) const
inline

Definition at line 339 of file RColumn.hxx.

◆ GetElement()

RColumnElementBase * ROOT::Experimental::Internal::RColumn::GetElement ( ) const
inline

Definition at line 336 of file RColumn.hxx.

◆ GetFirstElementIndex()

NTupleSize_t ROOT::Experimental::Internal::RColumn::GetFirstElementIndex ( ) const
inline

Definition at line 340 of file RColumn.hxx.

◆ GetGlobalIndex()

NTupleSize_t ROOT::Experimental::Internal::RColumn::GetGlobalIndex ( RClusterIndex  clusterIndex)
inline

Definition at line 276 of file RColumn.hxx.

◆ GetHandleSink()

RPageStorage::ColumnHandle_t ROOT::Experimental::Internal::RColumn::GetHandleSink ( ) const
inline

Definition at line 344 of file RColumn.hxx.

◆ GetHandleSource()

RPageStorage::ColumnHandle_t ROOT::Experimental::Internal::RColumn::GetHandleSource ( ) const
inline

Definition at line 343 of file RColumn.hxx.

◆ GetIndex()

std::uint32_t ROOT::Experimental::Internal::RColumn::GetIndex ( ) const
inline

Definition at line 338 of file RColumn.hxx.

◆ GetModel()

const RColumnModel & ROOT::Experimental::Internal::RColumn::GetModel ( ) const
inline

Definition at line 337 of file RColumn.hxx.

◆ GetNElements()

NTupleSize_t ROOT::Experimental::Internal::RColumn::GetNElements ( ) const
inline

Definition at line 335 of file RColumn.hxx.

◆ GetPageSink()

RPageSink * ROOT::Experimental::Internal::RColumn::GetPageSink ( ) const
inline

Definition at line 342 of file RColumn.hxx.

◆ GetPageSource()

RPageSource * ROOT::Experimental::Internal::RColumn::GetPageSource ( ) const
inline

Definition at line 341 of file RColumn.hxx.

◆ GetSwitchInfo()

void ROOT::Experimental::Internal::RColumn::GetSwitchInfo ( NTupleSize_t  globalIndex,
RClusterIndex varIndex,
std::uint32_t *  tag 
)
inline

Get the currently active cluster id.

Definition at line 326 of file RColumn.hxx.

◆ HandleWritePageIfFull()

void ROOT::Experimental::Internal::RColumn::HandleWritePageIfFull ( )
inlineprivate

Used in Append() and AppendV() to handle the case when the main page reached the target size.

If tail page optimization is enabled, switch the pages; the other page has been flushed when the main page reached 50%. Without tail page optimization, flush the current page to make room for future writes.

Definition at line 85 of file RColumn.hxx.

◆ Map() [1/2]

template<typename CppT >
CppT * ROOT::Experimental::Internal::RColumn::Map ( const NTupleSize_t  globalIndex)
inline

Definition at line 239 of file RColumn.hxx.

◆ Map() [2/2]

template<typename CppT >
CppT * ROOT::Experimental::Internal::RColumn::Map ( RClusterIndex  clusterIndex)
inline

Definition at line 245 of file RColumn.hxx.

◆ MapPage() [1/2]

void ROOT::Experimental::Internal::RColumn::MapPage ( const NTupleSize_t  index)

Definition at line 96 of file RColumn.cxx.

◆ MapPage() [2/2]

void ROOT::Experimental::Internal::RColumn::MapPage ( RClusterIndex  clusterIndex)

Definition at line 106 of file RColumn.cxx.

◆ MapV() [1/2]

template<typename CppT >
CppT * ROOT::Experimental::Internal::RColumn::MapV ( const NTupleSize_t  globalIndex,
NTupleSize_t nItems 
)
inline

Definition at line 252 of file RColumn.hxx.

◆ MapV() [2/2]

template<typename CppT >
CppT * ROOT::Experimental::Internal::RColumn::MapV ( RClusterIndex  clusterIndex,
NTupleSize_t nItems 
)
inline

Definition at line 264 of file RColumn.hxx.

◆ operator=()

RColumn & ROOT::Experimental::Internal::RColumn::operator= ( const RColumn )
delete

◆ Read() [1/2]

void ROOT::Experimental::Internal::RColumn::Read ( const NTupleSize_t  globalIndex,
void *  to 
)
inline

Definition at line 178 of file RColumn.hxx.

◆ Read() [2/2]

void ROOT::Experimental::Internal::RColumn::Read ( RClusterIndex  clusterIndex,
void *  to 
)
inline

Definition at line 189 of file RColumn.hxx.

◆ ReadV() [1/2]

void ROOT::Experimental::Internal::RColumn::ReadV ( const NTupleSize_t  globalIndex,
const ClusterSize_t::ValueType  count,
void *  to 
)
inline

Definition at line 200 of file RColumn.hxx.

◆ ReadV() [2/2]

void ROOT::Experimental::Internal::RColumn::ReadV ( RClusterIndex  clusterIndex,
const ClusterSize_t::ValueType  count,
void *  to 
)
inline

Definition at line 219 of file RColumn.hxx.

Member Data Documentation

◆ fApproxNElementsPerPage

std::uint32_t ROOT::Experimental::Internal::RColumn::fApproxNElementsPerPage = 0
private

For writing, the targeted number of elements, given by fApproxNElementsPerPage (in the write options) and the element size.

We ensure this value to be >= 2 in Connect() so that we have meaningful "page full" and "page half full" events when writing the page.

Definition at line 67 of file RColumn.hxx.

◆ fColumnIdSource

ColumnId_t ROOT::Experimental::Internal::RColumn::fColumnIdSource = kInvalidColumnId
private

The column id is used to find matching pages with content when reading.

Definition at line 73 of file RColumn.hxx.

◆ fElement

std::unique_ptr<RColumnElementBase> ROOT::Experimental::Internal::RColumn::fElement
private

Used to pack and unpack pages on writing/reading.

Definition at line 77 of file RColumn.hxx.

◆ fFirstElementIndex

NTupleSize_t ROOT::Experimental::Internal::RColumn::fFirstElementIndex = 0
private

Global index of the first element in this column; usually == 0, unless it is a deferred column.

Definition at line 75 of file RColumn.hxx.

◆ fHandleSink

RPageStorage::ColumnHandle_t ROOT::Experimental::Internal::RColumn::fHandleSink
private

Definition at line 53 of file RColumn.hxx.

◆ fHandleSource

RPageStorage::ColumnHandle_t ROOT::Experimental::Internal::RColumn::fHandleSource
private

Definition at line 54 of file RColumn.hxx.

◆ fIndex

std::uint32_t ROOT::Experimental::Internal::RColumn::fIndex
private

Columns belonging to the same field are distinguished by their order.

E.g. for an std::string field, there is the offset column with index 0 and the character value column with index 1.

Definition at line 50 of file RColumn.hxx.

◆ fModel

RColumnModel ROOT::Experimental::Internal::RColumn::fModel
private

Definition at line 45 of file RColumn.hxx.

◆ fNElements

NTupleSize_t ROOT::Experimental::Internal::RColumn::fNElements = 0
private

The number of elements written resp. available in the column.

Definition at line 69 of file RColumn.hxx.

◆ fPageSink

RPageSink* ROOT::Experimental::Internal::RColumn::fPageSink = nullptr
private

Definition at line 51 of file RColumn.hxx.

◆ fPageSource

RPageSource* ROOT::Experimental::Internal::RColumn::fPageSource = nullptr
private

Definition at line 52 of file RColumn.hxx.

◆ fReadPage

RPage ROOT::Experimental::Internal::RColumn::fReadPage
private

The currently mapped page for reading.

Definition at line 71 of file RColumn.hxx.

◆ fWritePage

RPage ROOT::Experimental::Internal::RColumn::fWritePage[2]
private

A set of open pages into which new elements are being written.

The pages are used in rotation. If tail page optimization is enabled, they are 50% bigger than the target size given by the write options. The current page is filled until the target size, but it is only committed once the other write page is filled at least 50%. If a flush occurs earlier, a slightly oversized, single page will be committed. Without tail page optimization, only one page is allocated equal to the target size.

Definition at line 61 of file RColumn.hxx.

◆ fWritePageIdx

int ROOT::Experimental::Internal::RColumn::fWritePageIdx = 0
private

Index of the current write page.

Definition at line 63 of file RColumn.hxx.

Libraries for ROOT::Experimental::Internal::RColumn:

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