A page is a slice of a column that is mapped into memory.

The page provides an opaque memory buffer for uncompressed, unpacked data. It does not interpret the contents but it does now about the size (and thus the number) of the elements inside as well as the element number range within the backing column/cluster. For reading, pages are allocated and filled by the page source and then registered with the page pool. For writing, the page sink allocates uninitialized pages of a given size. The page has a pointer to its memory allocator so that it can release itself.

Definition at line 46 of file RPage.hxx.

Classes
class	RClusterInfo
	Stores information about the cluster in which this page resides. More...

Public Member Functions
	RPage ()=default

	RPage (ColumnId_t columnId, void buffer, RPageAllocator pageAllocator, ClusterSize_t::ValueType elementSize, ClusterSize_t::ValueType maxElements)

	RPage (const RPage &)=delete

	RPage (RPage &&other)

	~RPage ()

bool	Contains (NTupleSize_t globalIndex) const

bool	Contains (RClusterIndex clusterIndex) const

void *	GetBuffer () const

std::size_t	GetCapacity () const

const RClusterInfo &	GetClusterInfo () const

ClusterSize_t::ValueType	GetClusterRangeFirst () const

ClusterSize_t::ValueType	GetClusterRangeLast () const

ColumnId_t	GetColumnId () const

std::uint32_t	GetElementSize () const

NTupleSize_t	GetGlobalRangeFirst () const

NTupleSize_t	GetGlobalRangeLast () const

std::uint32_t	GetMaxElements () const

std::size_t	GetNBytes () const
	The space taken by column elements in the buffer.

std::uint32_t	GetNElements () const

void *	GrowUnchecked (ClusterSize_t::ValueType nElements)
	Called during writing: returns a pointer after the last element and increases the element counter in anticipation of the caller filling nElements in the page.

bool	IsEmpty () const

bool	IsNull () const

bool	IsValid () const

bool	operator!= (const RPage &other) const

RPage &	operator= (const RPage &)=delete

RPage &	operator= (RPage &&other)

bool	operator== (const RPage &other) const

void	Reset (NTupleSize_t rangeFirst)
	Forget all currently stored elements (size == 0) and set a new starting index.

void	ResetCluster (const RClusterInfo &clusterInfo)

void	SetWindow (const NTupleSize_t rangeFirst, const RClusterInfo &clusterInfo)
	Seek the page to a certain position of the column.

Static Public Member Functions
static const void *	GetPageZeroBuffer ()
	Return a pointer to the page zero buffer used if there is no on-disk data for a particular deferred column.

static RPage	MakePageZero (ColumnId_t columnId, ClusterSize_t::ValueType elementSize)
	Make a 'zero' page for column `columnId` (that is comprised of 0x00 bytes only).

Static Public Attributes
static constexpr size_t	kPageZeroSize = 64 * 1024

Private Attributes
void *	fBuffer = nullptr

RClusterInfo	fClusterInfo

ColumnId_t	fColumnId = kInvalidColumnId

std::uint32_t	fElementSize = 0

std::uint32_t	fMaxElements = 0
	The capacity of the page in number of elements.

std::uint32_t	fNElements = 0

RPageAllocator *	fPageAllocator = nullptr
	The allocator used to allocate fBuffer. Can be null if the buffer doesn't need to be freed.

NTupleSize_t	fRangeFirst = 0

Friends
class	RPageRef

#include <ROOT/RPage.hxx>

Constructor & Destructor Documentation

◆ RPage() [1/4]

ROOT::Experimental::Internal::RPage::RPage ( )

default

◆ RPage() [2/4]

ROOT::Experimental::Internal::RPage::RPage	(	ColumnId_t	columnId,
		void *	buffer,
		RPageAllocator *	pageAllocator,
		ClusterSize_t::ValueType	elementSize,
		ClusterSize_t::ValueType	maxElements )

inline

Definition at line 82 of file RPage.hxx.

◆ RPage() [3/4]

ROOT::Experimental::Internal::RPage::RPage ( const RPage & )

delete

◆ RPage() [4/4]

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

inline

Definition at line 92 of file RPage.hxx.

◆ ~RPage()

ROOT::Experimental::Internal::RPage::~RPage ( )

Definition at line 19 of file RPage.cxx.

Member Function Documentation

◆ Contains() [1/2]

bool ROOT::Experimental::Internal::RPage::Contains ( NTupleSize_t globalIndex ) const

inline

Definition at line 141 of file RPage.hxx.

◆ Contains() [2/2]

bool ROOT::Experimental::Internal::RPage::Contains ( RClusterIndex clusterIndex ) const

inline

Definition at line 145 of file RPage.hxx.

◆ GetBuffer()

void * ROOT::Experimental::Internal::RPage::GetBuffer ( ) const

inline

Definition at line 154 of file RPage.hxx.

◆ GetCapacity()

std::size_t ROOT::Experimental::Internal::RPage::GetCapacity ( ) const

inline

Definition at line 126 of file RPage.hxx.

◆ GetClusterInfo()

const RClusterInfo & ROOT::Experimental::Internal::RPage::GetClusterInfo ( ) const

inline

Definition at line 139 of file RPage.hxx.

◆ GetClusterRangeFirst()

ClusterSize_t::ValueType ROOT::Experimental::Internal::RPage::GetClusterRangeFirst ( ) const

inline

Definition at line 135 of file RPage.hxx.

◆ GetClusterRangeLast()

ClusterSize_t::ValueType ROOT::Experimental::Internal::RPage::GetClusterRangeLast ( ) const

inline

Definition at line 136 of file RPage.hxx.

◆ GetColumnId()

ColumnId_t ROOT::Experimental::Internal::RPage::GetColumnId ( ) const

inline

Definition at line 120 of file RPage.hxx.

◆ GetElementSize()

std::uint32_t ROOT::Experimental::Internal::RPage::GetElementSize ( ) const

inline

Definition at line 130 of file RPage.hxx.

◆ GetGlobalRangeFirst()

NTupleSize_t ROOT::Experimental::Internal::RPage::GetGlobalRangeFirst ( ) const

inline

Definition at line 133 of file RPage.hxx.

◆ GetGlobalRangeLast()

NTupleSize_t ROOT::Experimental::Internal::RPage::GetGlobalRangeLast ( ) const

inline

Definition at line 134 of file RPage.hxx.

◆ GetMaxElements()

std::uint32_t ROOT::Experimental::Internal::RPage::GetMaxElements ( ) const

inline

Definition at line 132 of file RPage.hxx.

◆ GetNBytes()

std::size_t ROOT::Experimental::Internal::RPage::GetNBytes ( ) const

inline

The space taken by column elements in the buffer.

Definition at line 122 of file RPage.hxx.

◆ GetNElements()

std::uint32_t ROOT::Experimental::Internal::RPage::GetNElements ( ) const

inline

Definition at line 131 of file RPage.hxx.

◆ GetPageZeroBuffer()

const void * ROOT::Experimental::Internal::RPage::GetPageZeroBuffer ( )

static

Return a pointer to the page zero buffer used if there is no on-disk data for a particular deferred column.

Definition at line 25 of file RPage.cxx.

◆ GrowUnchecked()

void * ROOT::Experimental::Internal::RPage::GrowUnchecked ( ClusterSize_t::ValueType nElements )

inline

Called during writing: returns a pointer after the last element and increases the element counter in anticipation of the caller filling nElements in the page.

It is the responsibility of the caller to prevent page overflows, i.e. that fNElements + nElements <= fMaxElements

Definition at line 158 of file RPage.hxx.

◆ IsEmpty()

bool ROOT::Experimental::Internal::RPage::IsEmpty ( ) const

inline

Definition at line 184 of file RPage.hxx.

◆ IsNull()

bool ROOT::Experimental::Internal::RPage::IsNull ( ) const

inline

Definition at line 183 of file RPage.hxx.

◆ IsValid()

bool ROOT::Experimental::Internal::RPage::IsValid ( ) const

inline

Definition at line 182 of file RPage.hxx.

◆ MakePageZero()

static RPage ROOT::Experimental::Internal::RPage::MakePageZero	(	ColumnId_t	columnId,
		ClusterSize_t::ValueType	elementSize )

inlinestatic

Make a 'zero' page for column columnId (that is comprised of 0x00 bytes only).

The caller is responsible for invoking GrowUnchecked() and SetWindow() as appropriate.

Definition at line 174 of file RPage.hxx.

◆ operator!=()

bool ROOT::Experimental::Internal::RPage::operator!= ( const RPage & other ) const

inline

Definition at line 186 of file RPage.hxx.

◆ operator=() [1/2]

RPage & ROOT::Experimental::Internal::RPage::operator= ( const RPage & )

delete

◆ operator=() [2/2]

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

inline

Definition at line 104 of file RPage.hxx.

◆ operator==()

bool ROOT::Experimental::Internal::RPage::operator== ( const RPage & other ) const

inline

Definition at line 185 of file RPage.hxx.

◆ Reset()

void ROOT::Experimental::Internal::RPage::Reset ( NTupleSize_t rangeFirst )

inline

Forget all currently stored elements (size == 0) and set a new starting index.

Definition at line 169 of file RPage.hxx.

◆ ResetCluster()

void ROOT::Experimental::Internal::RPage::ResetCluster ( const RClusterInfo & clusterInfo )

inline

Definition at line 170 of file RPage.hxx.

◆ SetWindow()

void ROOT::Experimental::Internal::RPage::SetWindow	(	const NTupleSize_t	rangeFirst,
		const RClusterInfo &	clusterInfo )

inline

Seek the page to a certain position of the column.

Definition at line 164 of file RPage.hxx.

Friends And Related Symbol Documentation

◆ RPageRef

friend class RPageRef

friend

Definition at line 47 of file RPage.hxx.

Member Data Documentation

◆ fBuffer

void* ROOT::Experimental::Internal::RPage::fBuffer = nullptr

private

Definition at line 70 of file RPage.hxx.

◆ fClusterInfo

RClusterInfo ROOT::Experimental::Internal::RPage::fClusterInfo

private

Definition at line 78 of file RPage.hxx.

◆ fColumnId

ColumnId_t ROOT::Experimental::Internal::RPage::fColumnId = kInvalidColumnId

private

Definition at line 69 of file RPage.hxx.

◆ fElementSize

std::uint32_t ROOT::Experimental::Internal::RPage::fElementSize = 0

private

Definition at line 73 of file RPage.hxx.

◆ fMaxElements

std::uint32_t ROOT::Experimental::Internal::RPage::fMaxElements = 0

private

The capacity of the page in number of elements.

Definition at line 76 of file RPage.hxx.

◆ fNElements

std::uint32_t ROOT::Experimental::Internal::RPage::fNElements = 0

private

Definition at line 74 of file RPage.hxx.

◆ fPageAllocator

RPageAllocator* ROOT::Experimental::Internal::RPage::fPageAllocator = nullptr

private

The allocator used to allocate fBuffer. Can be null if the buffer doesn't need to be freed.

Definition at line 72 of file RPage.hxx.

◆ fRangeFirst

NTupleSize_t ROOT::Experimental::Internal::RPage::fRangeFirst = 0

private

Definition at line 77 of file RPage.hxx.

◆ kPageZeroSize

constexpr size_t ROOT::Experimental::Internal::RPage::kPageZeroSize = 64 * 1024

staticconstexpr

Definition at line 50 of file RPage.hxx.

Libraries for ROOT::Experimental::Internal::RPage:

[legend]

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

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

Classes

Public Member Functions

Static Public Member Functions

Static Public Attributes

Private Attributes

Friends

Constructor & Destructor Documentation

◆ RPage() [1/4]

◆ RPage() [2/4]

◆ RPage() [3/4]

◆ RPage() [4/4]

◆ ~RPage()

Member Function Documentation

◆ Contains() [1/2]

◆ Contains() [2/2]

◆ GetBuffer()

◆ GetCapacity()

◆ GetClusterInfo()

◆ GetClusterRangeFirst()

◆ GetClusterRangeLast()

◆ GetColumnId()

◆ GetElementSize()

◆ GetGlobalRangeFirst()

◆ GetGlobalRangeLast()

◆ GetMaxElements()

◆ GetNBytes()

◆ GetNElements()

◆ GetPageZeroBuffer()

◆ GrowUnchecked()

◆ IsEmpty()

◆ IsNull()

◆ IsValid()

◆ MakePageZero()

◆ operator!=()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ operator==()

◆ Reset()

◆ ResetCluster()

◆ SetWindow()

Friends And Related Symbol Documentation

◆ RPageRef

Member Data Documentation

◆ fBuffer

◆ fClusterInfo

◆ fColumnId

◆ fElementSize

◆ fMaxElements

◆ fNElements

◆ fPageAllocator

◆ fRangeFirst

◆ kPageZeroSize