ROOT::Experimental::Internal::RPagePool Class Reference

A thread-safe cache of pages loaded from the page source.

The page pool is used as a cache for pages loaded from a page source. In this way, identical page needed at the same time, only need to be loaded once. Page sources also use the page pool to stage (preload) pages unsealed by IMT tasks.

Definition at line 45 of file RPagePool.hxx.

Classes
struct	RPageInfo

Public Member Functions
	RPagePool ()=default
	RPagePool (const RPagePool &)=delete
	~RPagePool ()=default
RPageRef	GetPage (ColumnId_t columnId, std::type_index inMemoryType, NTupleSize_t globalIndex)
	Tries to find the page corresponding to column and index in the cache.
RPageRef	GetPage (ColumnId_t columnId, std::type_index inMemoryType, RClusterIndex clusterIndex)
RPagePool &	operator= (const RPagePool &)=delete
void	PreloadPage (RPage page, std::type_index inMemoryType)
	Like RegisterPage() but the reference counter is initialized to 0.
RPageRef	RegisterPage (RPage page, std::type_index inMemoryType)
	Adds a new page to the pool.

Private Member Functions
void	ReleasePage (const RPage &page)
	Give back a page to the pool and decrease the reference counter.

Private Attributes
std::mutex	fLock
std::vector< RPageInfo >	fPageInfos
std::vector< RPage >	fPages
	TODO(jblomer): should be an efficient index structure that allows.
std::vector< std::int32_t >	fReferences

Friends
class	RPageRef

#include <ROOT/RPagePool.hxx>

Constructor & Destructor Documentation

RPagePool() [1/2]

ROOT::Experimental::Internal::RPagePool::RPagePool ( )

default

RPagePool() [2/2]

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

delete

~RPagePool()

ROOT::Experimental::Internal::RPagePool::~RPagePool ( )

default

Member Function Documentation

GetPage() [1/2]

ROOT::Experimental::Internal::RPageRef ROOT::Experimental::Internal::RPagePool::GetPage	(	ColumnId_t	columnId,
		std::type_index	inMemoryType,
		NTupleSize_t	globalIndex )

Tries to find the page corresponding to column and index in the cache.

If the page is found, its reference counter is increased

Definition at line 64 of file RPagePool.cxx.

GetPage() [2/2]

ROOT::Experimental::Internal::RPageRef ROOT::Experimental::Internal::RPagePool::GetPage	(	ColumnId_t	columnId,
		std::type_index	inMemoryType,
		RClusterIndex	clusterIndex )

Definition at line 82 of file RPagePool.cxx.

operator=()

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

delete

PreloadPage()

void ROOT::Experimental::Internal::RPagePool::PreloadPage	(	RPage	page,
		std::type_index	inMemoryType )

Like RegisterPage() but the reference counter is initialized to 0.

Definition at line 34 of file RPagePool.cxx.

RegisterPage()

ROOT::Experimental::Internal::RPageRef ROOT::Experimental::Internal::RPagePool::RegisterPage	(	RPage	page,
		std::type_index	inMemoryType )

Adds a new page to the pool.

Upon registration, the page pool takes ownership of the page's memory. The new page has its reference counter set to 1.

Definition at line 25 of file RPagePool.cxx.

ReleasePage()

void ROOT::Experimental::Internal::RPagePool::ReleasePage ( const RPage & page )

private

Give back a page to the pool and decrease the reference counter.

There must not be any pointers anymore into this page. If the reference counter drops to zero, the page pool might decide to call the deleter given in during registration. Called by the RPageRef destructor.

Definition at line 42 of file RPagePool.cxx.

Friends And Related Symbol Documentation

RPageRef

friend class RPageRef

friend

Definition at line 46 of file RPagePool.hxx.

Member Data Documentation

fLock

std::mutex ROOT::Experimental::Internal::RPagePool::fLock

private

Definition at line 60 of file RPagePool.hxx.

fPageInfos

std::vector<RPageInfo> ROOT::Experimental::Internal::RPagePool::fPageInfos

private

Definition at line 58 of file RPagePool.hxx.

fPages

std::vector<RPage> ROOT::Experimental::Internal::RPagePool::fPages

private

TODO(jblomer): should be an efficient index structure that allows.

• random insert
• random delete
• searching by page

Definition at line 57 of file RPagePool.hxx.

fReferences

std::vector<std::int32_t> ROOT::Experimental::Internal::RPagePool::fReferences

private

Definition at line 59 of file RPagePool.hxx.

Libraries for ROOT::Experimental::Internal::RPagePool:

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

• tree/ntuple/v7/inc/ROOT/RPagePool.hxx
• tree/ntuple/v7/src/RPagePool.cxx