ROOT::Experimental::Internal::RNTupleCompressor Class Reference

Helper class to compress data blocks in the ROOT compression frame format.

Definition at line 40 of file RNTupleZip.hxx.

Public Types
using	Writer_t = std::function<void(const void *buffer, size_t nbytes, size_t offset)>
	Data might be overwritten, if a zipped block in the middle of a large input data stream turns out to be uncompressible.

Public Member Functions
	RNTupleCompressor ()
	RNTupleCompressor (const RNTupleCompressor &other)=delete
	RNTupleCompressor (RNTupleCompressor &&other)=default
void *	GetZipBuffer ()
RNTupleCompressor &	operator= (const RNTupleCompressor &other)=delete
RNTupleCompressor &	operator= (RNTupleCompressor &&other)=default
size_t	Zip (const void *from, size_t nbytes, int compression)
	Returns the size of the compressed data block.
size_t	Zip (const void *from, size_t nbytes, int compression, Writer_t fnWriter)
	Returns the size of the compressed data.

Static Public Member Functions
static Writer_t	MakeMemCopyWriter (unsigned char *dest)
static std::size_t	Zip (const void *from, std::size_t nbytes, int compression, void *to)
	Returns the size of the compressed data, written into the provided output buffer.

Static Public Attributes
static constexpr size_t	kMaxSingleBlock = kMAXZIPBUF

Private Types
using	Buffer_t = std::array<unsigned char, kMAXZIPBUF>

Private Attributes
std::unique_ptr< Buffer_t >	fZipBuffer

#include <ROOT/RNTupleZip.hxx>

Member Typedef Documentation

Buffer_t

using ROOT::Experimental::Internal::RNTupleCompressor::Buffer_t = std::array<unsigned char, kMAXZIPBUF>

private

Definition at line 42 of file RNTupleZip.hxx.

Writer_t

using ROOT::Experimental::Internal::RNTupleCompressor::Writer_t = std::function<void(const void *buffer, size_t nbytes, size_t offset)>

Data might be overwritten, if a zipped block in the middle of a large input data stream turns out to be uncompressible.

Definition at line 48 of file RNTupleZip.hxx.

Constructor & Destructor Documentation

RNTupleCompressor() [1/3]

ROOT::Experimental::Internal::RNTupleCompressor::RNTupleCompressor ( )

inline

Definition at line 55 of file RNTupleZip.hxx.

RNTupleCompressor() [2/3]

ROOT::Experimental::Internal::RNTupleCompressor::RNTupleCompressor ( const RNTupleCompressor & other )

delete

RNTupleCompressor() [3/3]

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

default

Member Function Documentation

GetZipBuffer()

void * ROOT::Experimental::Internal::RNTupleCompressor::GetZipBuffer ( )

inline

Definition at line 168 of file RNTupleZip.hxx.

MakeMemCopyWriter()

static Writer_t ROOT::Experimental::Internal::RNTupleCompressor::MakeMemCopyWriter ( unsigned char * dest )

inlinestatic

Definition at line 49 of file RNTupleZip.hxx.

operator=() [1/2]

RNTupleCompressor & ROOT::Experimental::Internal::RNTupleCompressor::operator= ( const RNTupleCompressor & other )

delete

operator=() [2/2]

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

default

Zip() [1/3]

size_t ROOT::Experimental::Internal::RNTupleCompressor::Zip ( const void * from, size_t nbytes, int compression )

inline

Returns the size of the compressed data block.

The data is written into the zip buffer. This works only for small input buffer up to 16MB (kMAXZIPBUF)

Definition at line 103 of file RNTupleZip.hxx.

Zip() [2/3]

size_t ROOT::Experimental::Internal::RNTupleCompressor::Zip ( const void * from, size_t nbytes, int compression, Writer_t fnWriter )

inline

Returns the size of the compressed data.

Data is compressed in 16MB (kMAXZIPBUF) blocks and written piecewise using the provided writer

Definition at line 63 of file RNTupleZip.hxx.

Zip() [3/3]

static std::size_t ROOT::Experimental::Internal::RNTupleCompressor::Zip ( const void * from, std::size_t nbytes, int compression, void * to )

inlinestatic

Returns the size of the compressed data, written into the provided output buffer.

Definition at line 130 of file RNTupleZip.hxx.

Member Data Documentation

fZipBuffer

std::unique_ptr<Buffer_t> ROOT::Experimental::Internal::RNTupleCompressor::fZipBuffer

private

Definition at line 43 of file RNTupleZip.hxx.

kMaxSingleBlock

constexpr size_t ROOT::Experimental::Internal::RNTupleCompressor::kMaxSingleBlock = kMAXZIPBUF

staticconstexpr

Definition at line 53 of file RNTupleZip.hxx.

Libraries for ROOT::Experimental::Internal::RNTupleCompressor:

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

• tree/ntuple/v7/inc/ROOT/RNTupleZip.hxx