The RRawFileDavix class provides read-only access to remote non-ROOT files.

It uses the Davix library for the transport layer. It instructs the RRawFile base class to buffer in larger chunks than the default for local files, assuming that remote file access has high(er) latency.

Definition at line 34 of file RRawFileDavix.hxx.

Public Member Functions
	RRawFileDavix (std::string_view url, RRawFile::ROptions options)

	~RRawFileDavix ()

std::unique_ptr< RRawFile >	Clone () const final
	Create a new RawFile that accesses the same resource. The file pointer is reset to zero. More...

int	GetFeatures () const final
	Derived classes shall inform the user about the supported functionality, which can possibly depend on the file at hand. More...

Public Member Functions inherited from ROOT::Internal::RRawFile
	RRawFile (const RRawFile &)=delete

	RRawFile (std::string_view url, ROptions options)

virtual	~RRawFile ()

virtual std::unique_ptr< RRawFile >	Clone () const =0
	Create a new RawFile that accesses the same resource. The file pointer is reset to zero. More...

virtual int	GetFeatures () const =0
	Derived classes shall inform the user about the supported functionality, which can possibly depend on the file at hand. More...

std::uint64_t	GetSize ()
	Returns the size of the file. More...

void *	Map (size_t nbytes, std::uint64_t offset, std::uint64_t &mapdOffset)
	Memory mapping according to POSIX standard; in particular, new mappings of the same range replace older ones. More...

RRawFile &	operator= (const RRawFile &)=delete

size_t	Read (void *buffer, size_t nbytes)
	Read from fFilePos offset. Returns the actual number of bytes read. More...

size_t	ReadAt (void *buffer, size_t nbytes, std::uint64_t offset)
	Buffered read from a random position. More...

bool	Readln (std::string &line)
	Read the next line starting from the current value of fFilePos. Returns false if the end of the file is reached. More...

void	Seek (std::uint64_t offset)
	Change the cursor fFilePos. More...

void	Unmap (void *region, size_t nbytes)
	Receives a pointer returned by Map() and should have nbytes set to the full length of the mapping. More...

Protected Member Functions
std::uint64_t	GetSizeImpl () final
	Derived classes should return the file size or kUnknownFileSize. More...

void	OpenImpl () final
	OpenImpl() is called at most once and before any call to either DoReadAt or DoGetSize. More...

size_t	ReadAtImpl (void *buffer, size_t nbytes, std::uint64_t offset) final
	Derived classes should implement low-level reading without buffering. More...

Protected Member Functions inherited from ROOT::Internal::RRawFile
virtual std::uint64_t	GetSizeImpl ()=0
	Derived classes should return the file size or kUnknownFileSize. More...

virtual void *	MapImpl (size_t nbytes, std::uint64_t offset, std::uint64_t &mapdOffset)
	If a derived class supports mmap, the MapImpl and UnmapImpl calls are supposed to be implemented, too The default implementation throws an error. More...

virtual void	OpenImpl ()=0
	OpenImpl() is called at most once and before any call to either DoReadAt or DoGetSize. More...

virtual size_t	ReadAtImpl (void *buffer, size_t nbytes, std::uint64_t offset)=0
	Derived classes should implement low-level reading without buffering. More...

virtual void	UnmapImpl (void *region, size_t nbytes)
	Derived classes with mmap support must be able to unmap the memory area handed out by Map() More...

Private Attributes
std::unique_ptr< Internal::RDavixFileDes >	fFileDes

Additional Inherited Members
Public Types inherited from ROOT::Internal::RRawFile
enum class	ELineBreaks { kAuto , kSystem , kUnix , kWindows }
	kAuto detects the line break from the first line, kSystem picks the system's default More...

Static Public Member Functions inherited from ROOT::Internal::RRawFile
static std::unique_ptr< RRawFile >	Create (std::string_view url, ROptions options=ROptions())
	Factory method that returns a suitable concrete implementation according to the transport in the url. More...

static std::string	GetLocation (std::string_view url)
	Returns only the file location, e.g. "server/file" for http://server/file. More...

static std::string	GetTransport (std::string_view url)
	Returns only the transport protocol in lower case, e.g. "http" for HTTP://server/file. More...

Static Public Attributes inherited from ROOT::Internal::RRawFile
static constexpr int	kFeatureHasMmap = 0x02
	Map() and Unmap() are implemented. More...

static constexpr int	kFeatureHasSize = 0x01
	GetSize() does not return kUnknownFileSize. More...

static constexpr std::uint64_t	kUnknownFileSize = std::uint64_t(-1)
	Derived classes do not necessarily need to provide file size information but they can return "not known" instead. More...

Protected Attributes inherited from ROOT::Internal::RRawFile
std::uint64_t	fFilePos
	The current position in the file, which can be changed by Seek, Read, and Readln. More...

ROptions	fOptions

std::string	fUrl

#include <ROOT/RRawFileDavix.hxx>

Inheritance diagram for ROOT::Internal::RRawFileDavix:

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Constructor & Destructor Documentation

◆ RRawFileDavix()

ROOT::Internal::RRawFileDavix::RRawFileDavix	(	std::string_view	url,
		RRawFile::ROptions	options
	)

Definition at line 42 of file RRawFileDavix.cxx.

◆ ~RRawFileDavix()

ROOT::Internal::RRawFileDavix::~RRawFileDavix ( )

Definition at line 47 of file RRawFileDavix.cxx.

Member Function Documentation

◆ Clone()

std::unique_ptr< ROOT::Internal::RRawFile > ROOT::Internal::RRawFileDavix::Clone ( ) const

finalvirtual

Create a new RawFile that accesses the same resource. The file pointer is reset to zero.

Implements ROOT::Internal::RRawFile.

Definition at line 53 of file RRawFileDavix.cxx.

◆ GetFeatures()

int ROOT::Internal::RRawFileDavix::GetFeatures ( ) const

inlinefinalvirtual

Derived classes shall inform the user about the supported functionality, which can possibly depend on the file at hand.

Implements ROOT::Internal::RRawFile.

Definition at line 47 of file RRawFileDavix.hxx.

◆ GetSizeImpl()

std::uint64_t ROOT::Internal::RRawFileDavix::GetSizeImpl ( )

finalprotectedvirtual

Derived classes should return the file size or kUnknownFileSize.

Implements ROOT::Internal::RRawFile.

Definition at line 58 of file RRawFileDavix.cxx.

◆ OpenImpl()

void ROOT::Internal::RRawFileDavix::OpenImpl ( )

finalprotectedvirtual

OpenImpl() is called at most once and before any call to either DoReadAt or DoGetSize.

If fOptions.fBlocksize is negative, derived classes are responsible to set a sensible value. After a call to OpenImpl(), fOptions.fBlocksize must be larger or equal to zero.

Implements ROOT::Internal::RRawFile.

Definition at line 68 of file RRawFileDavix.cxx.

◆ ReadAtImpl()

size_t ROOT::Internal::RRawFileDavix::ReadAtImpl	(	void *	buffer,
		size_t	nbytes,
		std::uint64_t	offset
	)

finalprotectedvirtual

Derived classes should implement low-level reading without buffering.

Short reads indicate the end of the file, therefore derived classes should return nbytes bytes if available.

Implements ROOT::Internal::RRawFile.

Definition at line 79 of file RRawFileDavix.cxx.

Member Data Documentation

◆ fFileDes

std::unique_ptr<Internal::RDavixFileDes> ROOT::Internal::RRawFileDavix::fFileDes

private

Definition at line 36 of file RRawFileDavix.hxx.

Libraries for ROOT::Internal::RRawFileDavix:

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Public Member Functions

Protected Member Functions

Private Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ RRawFileDavix()

◆ ~RRawFileDavix()

Member Function Documentation

◆ Clone()

◆ GetFeatures()

◆ GetSizeImpl()

◆ OpenImpl()

◆ ReadAtImpl()

Member Data Documentation

◆ fFileDes