Kanzi  3.9.4
Kanzi Engine API
kanzi::WriteOnlyDiskFile Class Reference

Implements the File interface for writing files to a disk. More...

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

Inheritance diagram for kanzi::WriteOnlyDiskFile:
[legend]

Public Member Functions

const bytemap () override
 Creates a memory mapping of the disk file. More...
 
void read (char *buffer, uintmax_t count) override
 Reads data from a file. More...
 
void seek (SeekPosition position, intmax_t offset) override
 Sets the position in a file. More...
 
uintmax_t size () const override
 Gets the size of a file. More...
 
uintmax_t tell () const override
 Gets the current position in a file. More...
 
KZ_NO_DISCARD uintmax_t tryRead (char *buffer, uintmax_t count) override
 Tries to reads data from a file. More...
 
void write (const char *buffer, uintmax_t count) override
 Writes data to a file. More...
 
 WriteOnlyDiskFile (string_view filename)
 Constructor. More...
 
- Public Member Functions inherited from kanzi::File
virtual ~File ()
 Destructor. More...
 

Static Public Member Functions

static WriteOnlyDiskFileUniquePtr tryOpen (string_view filename)
 Factory function. More...
 

Protected Member Functions

 WriteOnlyDiskFile (detail::FileUniquePtr file)
 
- Protected Member Functions inherited from kanzi::File
 File ()
 

Protected Attributes

detail::FileUniquePtr m_fileHandle
 

Additional Inherited Members

- Public Types inherited from kanzi::File
enum  SeekPosition { SeekBegin, SeekCurrent }
 Seek origin enumeration for seek(). More...
 

Detailed Description

Implements the File interface for writing files to a disk.

Constructor & Destructor Documentation

◆ WriteOnlyDiskFile() [1/2]

kanzi::WriteOnlyDiskFile::WriteOnlyDiskFile ( string_view  filename)
explicit

Constructor.

Parameters
filenameThe name (including path) of the disk file to handle. Throws runtime_error if file cannot be accessed.

◆ WriteOnlyDiskFile() [2/2]

kanzi::WriteOnlyDiskFile::WriteOnlyDiskFile ( detail::FileUniquePtr  file)
protected

Member Function Documentation

◆ tryOpen()

static WriteOnlyDiskFileUniquePtr kanzi::WriteOnlyDiskFile::tryOpen ( string_view  filename)
static

Factory function.

Creates an object representing an open file handle to a disk file.

Parameters
filenameThe name (including path) of the disk file to handle.
Returns
Pointer to the object, or null when file cannot be accessed.

◆ read()

void kanzi::WriteOnlyDiskFile::read ( char *  buffer,
uintmax_t  count 
)
overridevirtual

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
bufferBuffer 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.
countNumber of bytes to read.
See also
write(), tell(), and map().

Implements kanzi::File.

◆ tryRead()

KZ_NO_DISCARD uintmax_t kanzi::WriteOnlyDiskFile::tryRead ( char *  buffer,
uintmax_t  count 
)
overridevirtual

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
bufferBuffer 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.
countNumber of bytes to read.
See also
write(), tell(), and map().
Returns
Returns the number of bytes read.

Implements kanzi::File.

◆ write()

void kanzi::WriteOnlyDiskFile::write ( const char *  buffer,
uintmax_t  count 
)
overridevirtual

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
bufferBuffer 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.
countNumber of bytes to write.
See also
read(), tell(), and map().

Implements kanzi::File.

◆ size()

uintmax_t kanzi::WriteOnlyDiskFile::size ( ) const
overridevirtual

Gets the size of a file.

Returns
Returns the size of a file in bytes.

Implements kanzi::File.

◆ tell()

uintmax_t kanzi::WriteOnlyDiskFile::tell ( ) const
overridevirtual

Gets the current position in a file.

Returns
Returns the position in a file in bytes.
See also
seek(), read(), and write().

Implements kanzi::File.

◆ seek()

void kanzi::WriteOnlyDiskFile::seek ( SeekPosition  position,
intmax_t  offset 
)
overridevirtual

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
positionSeek origin.
offsetOffset in bytes from the seek origin.
See also
SeekPosition and tell().

Implements kanzi::File.

◆ map()

const byte* kanzi::WriteOnlyDiskFile::map ( )
overridevirtual

Creates a memory mapping of the disk file.

Does nothing if the disk file has already been memory mapped.

Returns
Pointer to the view of the memory map.

Implements kanzi::File.

Member Data Documentation

◆ m_fileHandle

detail::FileUniquePtr kanzi::WriteOnlyDiskFile::m_fileHandle
protected

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