DAOS-specific user-tunable settings for storing ntuples.

Definition at line 36 of file RNTupleWriteOptionsDaos.hxx.

Public Member Functions
	~RNTupleWriteOptionsDaos () override=default

std::unique_ptr< RNTupleWriteOptions >	Clone () const override

uint32_t	GetMaxCageSize () const

const std::string &	GetObjectClass () const

void	SetMaxCageSize (uint32_t cageSz)
	Set the upper bound for page concatenation into cages, in bytes.

void	SetObjectClass (const std::string &val)
	Set the object class used to generate OIDs that relate to user data.

Public Member Functions inherited from ROOT::Experimental::RNTupleWriteOptions
virtual	~RNTupleWriteOptions ()=default

std::size_t	GetApproxUnzippedPageSize () const

std::size_t	GetApproxZippedClusterSize () const

int	GetCompression () const

bool	GetHasSmallClusters () const

std::size_t	GetMaxUnzippedClusterSize () const

bool	GetUseBufferedWrite () const

EImplicitMT	GetUseImplicitMT () const

void	SetApproxUnzippedPageSize (std::size_t val)

void	SetApproxZippedClusterSize (std::size_t val)

void	SetCompression (int val)

void	SetCompression (RCompressionSetting::EAlgorithm::EValues algorithm, int compressionLevel)

void	SetHasSmallClusters (bool val)

void	SetMaxUnzippedClusterSize (std::size_t val)

void	SetUseBufferedWrite (bool val)

void	SetUseImplicitMT (EImplicitMT val)

Private Attributes
uint32_t	fMaxCageSize = 16 * RNTupleWriteOptions::fApproxUnzippedPageSize
	The maximum cage size is set to the equivalent of 16 uncompressed pages - 1MiB by default.

std::string	fObjectClass {"SX"}

Additional Inherited Members
Public Types inherited from ROOT::Experimental::RNTupleWriteOptions
enum class	EImplicitMT { kOff , kDefault }

Static Public Attributes inherited from ROOT::Experimental::RNTupleWriteOptions
static constexpr std::uint64_t	kMaxSmallClusterSize = 512 * 1024 * 1024
	A maximum size of 512MB still allows for a vector of bool to be stored in a small cluster.

Protected Attributes inherited from ROOT::Experimental::RNTupleWriteOptions
std::size_t	fApproxUnzippedPageSize = 64 * 1024
	Should be just large enough so that the compression ratio does not benefit much more from larger pages.

std::size_t	fApproxZippedClusterSize = 50 * 1000 * 1000
	Approximation of the target compressed cluster size.

int	fCompression {RCompressionSetting::EDefaults::kUseGeneralPurpose}

bool	fHasSmallClusters = false
	If set, 64bit index columns are replaced by 32bit index columns.

std::size_t	fMaxUnzippedClusterSize = 512 * 1024 * 1024
	Memory limit for committing a cluster: with very high compression ratio, we need a limit on how large the I/O buffer can grow during writing.

bool	fUseBufferedWrite = true

EImplicitMT	fUseImplicitMT = EImplicitMT::kDefault

#include <ROOT/RNTupleWriteOptionsDaos.hxx>

Inheritance diagram for ROOT::Experimental::RNTupleWriteOptionsDaos:

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Constructor & Destructor Documentation

◆ ~RNTupleWriteOptionsDaos()

ROOT::Experimental::RNTupleWriteOptionsDaos::~RNTupleWriteOptionsDaos ( )

overridedefault

Member Function Documentation

◆ Clone()

std::unique_ptr< RNTupleWriteOptions > ROOT::Experimental::RNTupleWriteOptionsDaos::Clone ( ) const

inlineoverridevirtual

Reimplemented from ROOT::Experimental::RNTupleWriteOptions.

Definition at line 45 of file RNTupleWriteOptionsDaos.hxx.

◆ GetMaxCageSize()

uint32_t ROOT::Experimental::RNTupleWriteOptionsDaos::GetMaxCageSize ( ) const

inline

Definition at line 56 of file RNTupleWriteOptionsDaos.hxx.

◆ GetObjectClass()

const std::string & ROOT::Experimental::RNTupleWriteOptionsDaos::GetObjectClass ( ) const

inline

Definition at line 50 of file RNTupleWriteOptionsDaos.hxx.

◆ SetMaxCageSize()

void ROOT::Experimental::RNTupleWriteOptionsDaos::SetMaxCageSize ( uint32_t cageSz )

inline

Set the upper bound for page concatenation into cages, in bytes.

It is assumed that cage size will be no smaller than the approximate uncompressed page size. To disable page concatenation, set this value to 0.

Definition at line 60 of file RNTupleWriteOptionsDaos.hxx.

◆ SetObjectClass()

void ROOT::Experimental::RNTupleWriteOptionsDaos::SetObjectClass ( const std::string & val )

inline

Set the object class used to generate OIDs that relate to user data.

Any OC_xxx constant defined in daos_obj_class.h may be used here without the OC_ prefix.

Definition at line 54 of file RNTupleWriteOptionsDaos.hxx.

Member Data Documentation

◆ fMaxCageSize

uint32_t ROOT::Experimental::RNTupleWriteOptionsDaos::fMaxCageSize = 16 * RNTupleWriteOptions::fApproxUnzippedPageSize

private

The maximum cage size is set to the equivalent of 16 uncompressed pages - 1MiB by default.

Empirically, such a cage size yields acceptable results in throughput and page granularity for most use cases. A fMaxCageSize of 0 disables the caging mechanism.

Definition at line 41 of file RNTupleWriteOptionsDaos.hxx.