LittleFileSystem2, a little file system. More...

#include <LittleFileSystem2.h>

Inheritance diagram for LittleFileSystem2:

Public Member Functions
	LittleFileSystem2 (const char name=NULL, mbed::BlockDevice bd=NULL, lfs2_size_t block_size=MBED_LFS2_BLOCK_SIZE, uint32_t block_cycles=MBED_LFS2_BLOCK_CYCLES, lfs2_size_t cache_size=MBED_LFS2_CACHE_SIZE, lfs2_size_t lookahead=MBED_LFS2_LOOKAHEAD_SIZE)
	Lifetime of the LittleFileSystem2. More...

virtual int	mount (mbed::BlockDevice *bd)
	Mount a file system to a block device. More...

virtual int	unmount ()
	Unmount a file system from the underlying block device. More...

virtual int	reformat (mbed::BlockDevice *bd)
	Reformat a file system. More...

virtual int	remove (const char *path)
	Remove a file from the file system. More...

virtual int	rename (const char path, const char newpath)
	Rename a file in the file system. More...

virtual int	stat (const char path, struct stat st)
	Store information about the file in a stat structure. More...

virtual int	mkdir (const char *path, mode_t mode)
	Create a directory in the file system. More...

virtual int	statvfs (const char path, struct statvfs buf)
	Store information about the mounted file system in a statvfs structure. More...

Static Public Member Functions
static int	format (mbed::BlockDevice *bd, lfs2_size_t block_size=MBED_LFS2_BLOCK_SIZE, uint32_t block_cycles=MBED_LFS2_BLOCK_CYCLES, lfs2_size_t cache_size=MBED_LFS2_CACHE_SIZE, lfs2_size_t lookahead_size=MBED_LFS2_LOOKAHEAD_SIZE)
	Format a block device with the LittleFileSystem2. More...

static FileSystem *	get_default_instance ()
	Return the default file system. More...

Protected Member Functions
virtual int	open (FileHandle *file, const char path, int flags)
	defined(DOXYGEN_ONLY) More...

virtual int	open (DirHandle *dir, const char path)
	Open a directory on the filesystem. More...

Detailed Description

LittleFileSystem2, a little file system.

Synchronization level: Thread safe

Definition at line 36 of file LittleFileSystem2.h.

Constructor & Destructor Documentation

◆ LittleFileSystem2()

LittleFileSystem2	(	const char *	name = `NULL`,
		mbed::BlockDevice *	bd = `NULL`,
		lfs2_size_t	block_size = `MBED_LFS2_BLOCK_SIZE`,
		uint32_t	block_cycles = `MBED_LFS2_BLOCK_CYCLES`,
		lfs2_size_t	cache_size = `MBED_LFS2_CACHE_SIZE`,
		lfs2_size_t	lookahead = `MBED_LFS2_LOOKAHEAD_SIZE`
	)

Lifetime of the LittleFileSystem2.

Parameters

name	Name of the file system in the tree.
bd	Block device to mount. Mounted immediately if not NULL.
block_size	Size of a logical block. This does not impact ram consumption and may be larger than the physical erase block. If the physical erase block is larger, littlefs will use that instead. Larger values will be faster but waste more storage when files are not aligned to a block size.
block_cycles	Number of erase cycles before a block is forcefully evicted. Larger values are more efficient but cause less even wear distribution. 0 disables dynamic wear-leveling.
cache_size	Size of read/program caches. Each file uses 1 cache, and littlefs allocates 2 caches for internal operations. Larger values should be faster but uses more RAM.
lookahead	Size of the lookahead buffer. A larger lookahead reduces the allocation scans and results in a faster filesystem but uses more RAM.

Member Function Documentation

◆ format()

static int format	(	mbed::BlockDevice *	bd,
		lfs2_size_t	block_size = `MBED_LFS2_BLOCK_SIZE`,
		uint32_t	block_cycles = `MBED_LFS2_BLOCK_CYCLES`,
		lfs2_size_t	cache_size = `MBED_LFS2_CACHE_SIZE`,
		lfs2_size_t	lookahead_size = `MBED_LFS2_LOOKAHEAD_SIZE`
	)

static

Format a block device with the LittleFileSystem2.

The block device to format should be mounted when this function is called.

Parameters

bd	This is the block device that will be formatted.
block_size	Size of a logical block. This does not impact ram consumption and may be larger than the physical erase block. If the physical erase block is larger, littlefs will use that instead. Larger values will be faster but waste more storage when files are not aligned to a block size.
block_cycles	Number of erase cycles before a block is forcefully evicted. Larger values are more efficient but cause less even wear distribution. 0 disables dynamic wear-leveling.
cache_size	Size of read/program caches. Each file uses 1 cache, and littlefs allocates 2 caches for internal operations. Larger values should be faster but uses more RAM.
lookahead_size	Size of the lookahead buffer. A larger lookahead reduces the allocation scans and results in a faster filesystem but uses more RAM.

◆ mount()

virtual int mount ( mbed::BlockDevice * bd )

virtual

Mount a file system to a block device.

Parameters

bd	Block device to mount to.

Returns: 0 on success, negative error code on failure.

Implements FileSystem.

◆ unmount()

virtual int unmount ( )

virtual

Unmount a file system from the underlying block device.

Returns: 0 on success, negative error code on failure

Implements FileSystem.

◆ reformat()

virtual int reformat ( mbed::BlockDevice * bd )

virtual

Reformat a file system.

Results in an empty and mounted file system.

Parameters

bd	Block device to reformat and mount. If NULL, the mounted Block device is used. Note: If mount fails, bd must be provided. Default: NULL

Returns: 0 on success, negative error code on failure

Reimplemented from FileSystem.

◆ remove()

virtual int remove ( const char * path )

virtual

Remove a file from the file system.

Parameters

path	The name of the file to remove.

Returns: 0 on success, negative error code on failure

Reimplemented from FileSystem.

◆ rename()

virtual int rename	(	const char *	path,
		const char *	newpath
	)

virtual

Rename a file in the file system.

Parameters

path	The name of the file to rename.
newpath	The name to rename it to.

Returns: 0 on success, negative error code on failure

Reimplemented from FileSystem.

◆ stat()

virtual int stat	(	const char *	path,
		struct stat *	st
	)

virtual

Store information about the file in a stat structure.

Parameters

path	The name of the file to find information about.
st	The stat buffer to write to.

Returns: 0 on success, negative error code on failure

Reimplemented from FileSystem.

◆ mkdir()

virtual int mkdir	(	const char *	path,
		mode_t	mode
	)

virtual

Create a directory in the file system.

Parameters

path	The name of the directory to create.
mode	The permissions with which to create the directory.

Returns: 0 on success, negative error code on failure

Reimplemented from FileSystem.

◆ statvfs()

virtual int statvfs	(	const char *	path,
		struct statvfs *	buf
	)

virtual

Store information about the mounted file system in a statvfs structure.

Parameters

path	The name of the file to find information about.
buf	The stat buffer to write to.

Returns: 0 on success, negative error code on failure

Reimplemented from FileSystem.

◆ get_default_instance()

static FileSystem * get_default_instance ( )

staticinherited

Return the default file system.

Returns the default file system based on the default block device configuration. Use the components in target.json or application config to change the default block device and affect the default filesystem. SD block device => FAT filesystem QSPIF, SPIF, DATAFLASH or FLAHIAP block device => LITTLE filesystem

An application can override all target settings by implementing FileSystem::get_default_instance() - the default definition is weak, and calls get_target_default_instance().

◆ open() [1/2]

virtual int open	(	FileHandle **	file,
		const char *	path,
		int	flags
	)

protectedvirtualinherited

defined(DOXYGEN_ONLY)

Implements FileSystemHandle.

◆ open() [2/2]

virtual int open	(	DirHandle **	dir,
		const char *	path
	)

protectedvirtualinherited

Open a directory on the filesystem.

Parameters

dir	Destination for the handle to the directory
path	Name of the directory to open

Returns: 0 on success, negative error code on failure

Reimplemented from FileSystemHandle.

Public Member Functions

Static Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ LittleFileSystem2()

Member Function Documentation

◆ format()

◆ mount()

◆ unmount()

◆ reformat()

◆ remove()

◆ rename()

◆ stat()

◆ mkdir()

◆ statvfs()

◆ get_default_instance()

◆ open() [1/2]

◆ open() [2/2]