Base interface for a file stream provider. It is intended to be implemented for specific file protocol. More...

#include <OSD_FileSystem.hxx>

Inheritance diagram for OSD_FileSystem:

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Public Member Functions
virtual bool	IsSupportedPath (const TCollection_AsciiString &theUrl) const =0
	Returns TRUE if URL defines a supported protocol.

virtual bool	IsOpenIStream (const std::shared_ptr< std::istream > &theStream) const =0
	Returns TRUE if current input stream is opened for reading operations.

virtual bool	IsOpenOStream (const std::shared_ptr< std::ostream > &theStream) const =0
	Returns TRUE if current output stream is opened for writing operations.

virtual std::shared_ptr< std::istream >	OpenIStream (const TCollection_AsciiString &theUrl, const std::ios_base::openmode theMode, const int64_t theOffset=0, const std::shared_ptr< std::istream > &theOldStream=std::shared_ptr< std::istream >())
	Opens stream for specified file URL for reading operations (std::istream). Default implementation create a stream from file buffer returned by OSD_FileSystem::OpenFileBuffer().

virtual std::shared_ptr< std::ostream >	OpenOStream (const TCollection_AsciiString &theUrl, const std::ios_base::openmode theMode)
	Opens stream for specified file URL for writing operations (std::ostream). Default implementation create a stream from file buffer returned by OSD_FileSystem::OpenFileBuffer().

virtual std::shared_ptr< std::streambuf >	OpenStreamBuffer (const TCollection_AsciiString &theUrl, const std::ios_base::openmode theMode, const int64_t theOffset=0, int64_t *theOutBufSize=nullptr)=0
	Opens stream buffer for specified file URL.

	OSD_FileSystem ()
	Constructor.

	~OSD_FileSystem () override
	Destructor.

Public Member Functions inherited from Standard_Transient
	Standard_Transient ()
	Empty constructor.

	Standard_Transient (const Standard_Transient &)
	Copy constructor – does nothing.

Standard_Transient &	operator= (const Standard_Transient &)
	Assignment operator, needed to avoid copying reference counter.

virtual	~Standard_Transient ()=default
	Destructor must be virtual.

virtual const opencascade::handle< Standard_Type > &	DynamicType () const
	Returns a type descriptor about this object.

bool	IsInstance (const opencascade::handle< Standard_Type > &theType) const
	Returns a true value if this is an instance of Type.

bool	IsInstance (const char *const theTypeName) const
	Returns a true value if this is an instance of TypeName.

bool	IsKind (const opencascade::handle< Standard_Type > &theType) const
	Returns true if this is an instance of Type or an instance of any class that inherits from Type. Note that multiple inheritance is not supported by OCCT RTTI mechanism.

bool	IsKind (const char *const theTypeName) const
	Returns true if this is an instance of TypeName or an instance of any class that inherits from TypeName. Note that multiple inheritance is not supported by OCCT RTTI mechanism.

Standard_Transient *	This () const
	Returns non-const pointer to this object (like const_cast). For protection against creating handle to objects allocated in stack or call from constructor, it will raise exception Standard_ProgramError if reference counter is zero.

int	GetRefCount () const noexcept
	Get the reference counter of this object.

void	IncrementRefCounter () noexcept
	Increments the reference counter of this object. Uses relaxed memory ordering since incrementing only requires atomicity, not synchronization with other memory operations.

int	DecrementRefCounter () noexcept
	Decrements the reference counter of this object; returns the decremented value. Uses release ordering for the decrement to ensure all writes to the object are visible before the count reaches zero. An acquire fence is added only when the count reaches zero, ensuring proper synchronization before deletion. This is more efficient than using acq_rel for every decrement.

virtual void	Delete () const
	Memory deallocator for transient classes.

Static Public Member Functions
static const occ::handle< OSD_FileSystem > &	DefaultFileSystem ()
	Returns a global file system, which a selector between registered file systems (OSD_FileSystemSelector).

static void	AddDefaultProtocol (const occ::handle< OSD_FileSystem > &theFileSystem, bool theIsPreferred=false)
	Registers file system within the global file system selector returned by OSD_FileSystem::DefaultFileSystem(). Note that registering protocols is not thread-safe operation and expected to be done once at application startup.

static void	RemoveDefaultProtocol (const occ::handle< OSD_FileSystem > &theFileSystem)
	Unregisters file system within the global file system selector returned by OSD_FileSystem::DefaultFileSystem().

Static Public Member Functions inherited from Standard_Transient
static constexpr const char *	get_type_name ()
	Returns a type descriptor about this object.

static const opencascade::handle< Standard_Type > &	get_type_descriptor ()
	Returns type descriptor of Standard_Transient class.

Additional Inherited Members
Public Types inherited from Standard_Transient
typedef void	base_type
	Returns a type descriptor about this object.

Detailed Description

Base interface for a file stream provider. It is intended to be implemented for specific file protocol.

Constructor & Destructor Documentation

◆ OSD_FileSystem()

OSD_FileSystem::OSD_FileSystem ( )

Constructor.

◆ ~OSD_FileSystem()

OSD_FileSystem::~OSD_FileSystem ( )

override

Destructor.

Member Function Documentation

◆ AddDefaultProtocol()

static void OSD_FileSystem::AddDefaultProtocol	(	const occ::handle< OSD_FileSystem > &	theFileSystem,
		bool	theIsPreferred = false )

static

Registers file system within the global file system selector returned by OSD_FileSystem::DefaultFileSystem(). Note that registering protocols is not thread-safe operation and expected to be done once at application startup.

Parameters

[in]	theFileSystem	file system to register
[in]	theIsPreferred	add to the beginning of the list when TRUE, or add to the end otherwise

◆ DefaultFileSystem()

static const occ::handle< OSD_FileSystem > & OSD_FileSystem::DefaultFileSystem ( )

static

Returns a global file system, which a selector between registered file systems (OSD_FileSystemSelector).

◆ IsOpenIStream()

virtual bool OSD_FileSystem::IsOpenIStream ( const std::shared_ptr< std::istream > & theStream ) const

pure virtual

Returns TRUE if current input stream is opened for reading operations.

Implemented in OSD_CachedFileSystem, OSD_FileSystemSelector, and OSD_LocalFileSystem.

◆ IsOpenOStream()

virtual bool OSD_FileSystem::IsOpenOStream ( const std::shared_ptr< std::ostream > & theStream ) const

pure virtual

Returns TRUE if current output stream is opened for writing operations.

Implemented in OSD_CachedFileSystem, OSD_FileSystemSelector, and OSD_LocalFileSystem.

◆ IsSupportedPath()

virtual bool OSD_FileSystem::IsSupportedPath ( const TCollection_AsciiString & theUrl ) const

pure virtual

Returns TRUE if URL defines a supported protocol.

Implemented in OSD_CachedFileSystem, OSD_FileSystemSelector, and OSD_LocalFileSystem.

◆ OpenIStream()

virtual std::shared_ptr< std::istream > OSD_FileSystem::OpenIStream	(	const TCollection_AsciiString &	theUrl,
		const std::ios_base::openmode	theMode,
		const int64_t	theOffset = 0,
		const std::shared_ptr< std::istream > &	theOldStream = std::shared_ptr< std::istream >() )

virtual

Opens stream for specified file URL for reading operations (std::istream). Default implementation create a stream from file buffer returned by OSD_FileSystem::OpenFileBuffer().

Parameters

[in]	theUrl	path to open
[in]	theMode	flags describing the requested input mode for the stream (std::ios_base::in will be implicitly added)
[in]	theOffset	expected stream position from the beginning of the file (beginning of the stream by default); -1 would keep seek position undefined (in case of reusing theOldStream)
[in]	theOldStream	a pointer to existing stream pointing to theUrl to be reused (without re-opening)

Returns: pointer to newly created opened stream, to theOldStream if it can be reused or NULL in case of failure.

Reimplemented in OSD_FileSystemSelector, and OSD_CachedFileSystem.

◆ OpenOStream()

virtual std::shared_ptr< std::ostream > OSD_FileSystem::OpenOStream	(	const TCollection_AsciiString &	theUrl,
		const std::ios_base::openmode	theMode )

virtual

Opens stream for specified file URL for writing operations (std::ostream). Default implementation create a stream from file buffer returned by OSD_FileSystem::OpenFileBuffer().

Parameters

[in]	theUrl	path to open
[in]	theMode	flags describing the requested output mode for the stream (std::ios_base::out will be implicitly added)

Returns: pointer to newly created opened stream or NULL in case of failure.

Reimplemented in OSD_CachedFileSystem, and OSD_FileSystemSelector.

◆ OpenStreamBuffer()

virtual std::shared_ptr< std::streambuf > OSD_FileSystem::OpenStreamBuffer	(	const TCollection_AsciiString &	theUrl,
		const std::ios_base::openmode	theMode,
		const int64_t	theOffset = 0,
		int64_t *	theOutBufSize = nullptr )

pure virtual

Opens stream buffer for specified file URL.

Parameters

[in]	theUrl	path to open
[in]	theMode	flags describing the requested input mode for the stream
[in]	theOffset	expected stream position from the beginning of the buffer (beginning of the stream buffer by default)
[out]	theOutBufSize	total buffer size (only if buffer is opened for read)

Returns: pointer to newly created opened stream buffer or NULL in case of failure.

Implemented in OSD_CachedFileSystem, OSD_FileSystemSelector, and OSD_LocalFileSystem.

◆ RemoveDefaultProtocol()

static void OSD_FileSystem::RemoveDefaultProtocol ( const occ::handle< OSD_FileSystem > & theFileSystem )

static

Unregisters file system within the global file system selector returned by OSD_FileSystem::DefaultFileSystem().

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

OSD_FileSystem.hxx

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ OSD_FileSystem()

◆ ~OSD_FileSystem()

Member Function Documentation

◆ AddDefaultProtocol()

◆ DefaultFileSystem()

◆ IsOpenIStream()

◆ IsOpenOStream()

◆ IsSupportedPath()

◆ OpenIStream()

◆ OpenOStream()

◆ OpenStreamBuffer()

◆ RemoveDefaultProtocol()