Interface class for files. More...

#include <kanzi/core/file/file.hpp>

Inheritance diagram for kanzi::File:

Public Types
enum	SeekPosition { SeekBegin, SeekCurrent }
	Seek origin enumeration for seek(). More...

Public Member Functions
virtual const byte *	map ()=0
	Maps the contents of a file to the process memory. More...

virtual void	read (char *buffer, uintmax_t count)=0
	Reads data from a file. More...

virtual void	seek (SeekPosition position, intmax_t offset)=0
	Sets the position in a file. More...

virtual uintmax_t	size () const =0
	Gets the size of a file. More...

virtual uintmax_t	tell () const =0
	Gets the current position in a file. More...

virtual KZ_NO_DISCARD uintmax_t	tryRead (char *buffer, uintmax_t count)=0
	Tries to reads data from a file. More...

virtual void	write (const char *buffer, uintmax_t count)=0
	Writes data to a file. More...

virtual	~File ()
	Destructor. More...

Protected Member Functions
	File ()

Detailed Description

Interface class for files.

Use this interface to hide differences between file implementations.

See also: ReadOnlyDiskFile, ReadOnlyMemoryFile.

Member Enumeration Documentation

enum kanzi::File::SeekPosition

Seek origin enumeration for seek().

Enumerator
SeekBegin	Seek from start of file.
SeekCurrent	Seek from current file position.

Constructor & Destructor Documentation

virtual kanzi::File::~File ( )

inlinevirtual

Destructor.

kanzi::File::File ( )

inlineexplicitprotected

Member Function Documentation

virtual void kanzi::File::read	(	char *	buffer,
		uintmax_t	count
	)

pure virtual

Reads data from a file.

The function starts reading at the current file position. When you call read(), it invalidates the pointer returned by map(). This function throws when its can't read count number of bytes from the File.

Parameters

buffer	Buffer to which to read. The size of the buffer in bytes must be at least the size of the value you pass in the count parameter.
count	Number of bytes to read.

See also: write(), tell(), and map().

Implemented in kanzi::ReadOnlyDiskFile, kanzi::WriteOnlyDiskFile, and kanzi::ReadOnlyMemoryFile.

virtual KZ_NO_DISCARD uintmax_t kanzi::File::tryRead	(	char *	buffer,
		uintmax_t	count
	)

pure virtual

Tries to reads data from a file.

The function starts reading at the current file position. When you call tryRead(), it invalidates the pointer returned by map().

Parameters

buffer	Buffer to which to read. The size of the buffer in bytes must be at least the size of the value you pass in the count parameter.
count	Number of bytes to read.

See also: write(), tell(), and map().

Returns: Returns the number of bytes read.

Implemented in kanzi::ReadOnlyDiskFile, kanzi::WriteOnlyDiskFile, and kanzi::ReadOnlyMemoryFile.

virtual void kanzi::File::write	(	const char *	buffer,
		uintmax_t	count
	)

pure virtual

Writes data to a file.

The function starts writing at the current file position. When you call write(), it invalidates the pointer returned by map().

Parameters

buffer	Buffer from which to write. The size of the buffer in bytes must be at least the size of the value you pass in the count parameter.
count	Number of bytes to write.

See also: read(), tell(), and map().

Implemented in kanzi::ReadOnlyDiskFile, kanzi::WriteOnlyDiskFile, and kanzi::ReadOnlyMemoryFile.

virtual uintmax_t kanzi::File::size ( ) const

pure virtual

Gets the size of a file.

Returns: Returns the size of a file in bytes.

Implemented in kanzi::ReadOnlyDiskFile, kanzi::WriteOnlyDiskFile, and kanzi::ReadOnlyMemoryFile.

virtual uintmax_t kanzi::File::tell ( ) const

pure virtual

Gets the current position in a file.

Returns: Returns the position in a file in bytes.

See also: seek(), read(), and write().

Implemented in kanzi::ReadOnlyDiskFile, kanzi::WriteOnlyDiskFile, and kanzi::ReadOnlyMemoryFile.

virtual void kanzi::File::seek	(	SeekPosition	position,
		intmax_t	offset
	)

pure virtual

Sets the position in a file.

You can set the position as an offset to either the current position or the beginning of the file. When you call seek(), it invalidates the pointer returned by map().

Parameters