hi::v1::file_view Class Reference

#include <hikogui/file/file_view.hpp>

Public Member Functions
constexpr	file_view (file_view const &other) noexcept=default
constexpr	file_view (file_view &&other) noexcept=default
constexpr file_view &	operator= (file_view const &other) noexcept=default
constexpr file_view &	operator= (file_view &&other) noexcept=default
	file_view (file const &file, std::size_t offset=0, std::size_t size=0)
	Create a file-view from a file-mapping.
	file_view (std::filesystem::path const &path, access_mode access_mode=access_mode::open_for_read, std::size_t offset=0, std::size_t size=0)
std::size_t	offset () const noexcept
std::size_t	size () const noexcept
bool	unmapped () const noexcept
	Check if this file view is closed.
	operator bool () const noexcept
	Check if this file view is open.
void	unmap () noexcept
void_span	void_span () const noexcept
	Span to the mapping into memory.
const_void_span	const_void_span () const noexcept
void	flush (hi::void_span span) const noexcept
	Flush changes in memory to the open file view.

Friends
template<typename T>
std::span< T >	as_span (file_view const &view) noexcept
std::string_view	as_string_view (file_view const &view) noexcept
bstring_view	as_bstring_view (file_view const &view) noexcept

Detailed Description

Map a file into virtual memory.

To map a file into memory there are three objects needed:

• The file object which holds a handle or file descriptor to an open file on disk.
• The file_mapping object maps a section of the file in the operating system.
• The file_view object maps a section of the file-mapping into virtual memory.

The file_mapping intermediate object is required on Windows systems which holds a handle to a file mapping object.

Constructor & Destructor Documentation

file_view()

hi::v1::file_view::file_view	(	file const &	file,
		std::size_t	offset = 0,
		std::size_t	size = 0 )

Create a file-view from a file-mapping.

Note

The mapping object will be retained by this file-view.

Parameters

file	An open file object.
offset	The offset from the beginning of the file-mapping (a file mapping may have an offset on its own). The offset must also be a multiple of the granularity.
size	The size of the mapping, if zero the full file-mapping object is mapped.

Member Function Documentation

const_void_span()

const_void_span hi::v1::file_view::const_void_span ( ) const

inlinenodiscardnoexcept

Span to the mapping into memory.

flush()

void hi::v1::file_view::flush ( hi::void_span span ) const

inlinenoexcept

Flush changes in memory to the open file view.

Parameters

span	The part of the buffer to flush.

operator bool()

hi::v1::file_view::operator bool ( ) const

inlineexplicitnoexcept

Check if this file view is open.

Postcondition

Resources may be released if the file view is closed.

Returns

true of the file view is open.

unmapped()

bool hi::v1::file_view::unmapped ( ) const

inlinenodiscardnoexcept

Check if this file view is closed.

Postcondition

Resources may be released if the file view is closed.

Returns

true of the file view is closed.

void_span()

void_span hi::v1::file_view::void_span ( ) const

inlinenodiscardnoexcept

Span to the mapping into memory.

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

• hikogui/src/hikogui/file/file_view.hpp