FileSystemStore is a lightweight implementation of the KVStore interface over file systems. More...

#include <FileSystemStore.h>

Inheritance diagram for FileSystemStore:

Public Types
typedef struct mbed::KVStore::info	info_t
	Holds key information. More...

Public Member Functions
	FileSystemStore (FileSystem *fs)
	Create FileSystemStore - A Key Value API on top of FS. More...

virtual	~FileSystemStore ()
	Destroy FileSystemStore instance. More...

virtual int	init ()
	Initialize FileSystemStore, checking validity of KVStore writing folder and if it doesn't exist, creating it. More...

virtual int	deinit ()
	Deinitialize FileSystemStore, release and free resources. More...

virtual int	reset ()
	Reset FileSystemStore contents (clear all keys) More...

virtual int	set (const char key, const void buffer, size_t size, uint32_t create_flags)
	Set one FileSystemStore item, given key and value. More...

virtual int	get (const char key, void buffer, size_t buffer_size, size_t *actual_size=NULL, size_t offset=0)
	Get one FileSystemStore item by given key. More...

virtual int	get_info (const char key, info_t info)
	Get information of a given key. More...

virtual int	remove (const char *key)
	Remove a FileSystemStore item by given key. More...

virtual int	set_start (set_handle_t handle, const char key, size_t final_data_size, uint32_t create_flags)
	Start an incremental FileSystemStore set sequence. More...

virtual int	set_add_data (set_handle_t handle, const void *value_data, size_t data_size)
	Add data to incremental FileSystemStore set sequence. More...

virtual int	set_finalize (set_handle_t handle)
	Finalize an incremental FileSystemStore set sequence. More...

virtual int	iterator_open (iterator_t it, const char prefix=NULL)
	Start an iteration over FileSystemStore keys. More...

virtual int	iterator_next (iterator_t it, char *key, size_t key_size)
	Get next key in iteration. More...

virtual int	iterator_close (iterator_t it)
	Close iteration. More...

bool	is_valid_key (const char *key) const
	Convenience function for checking key validity. More...

Detailed Description

FileSystemStore is a lightweight implementation of the KVStore interface over file systems.

FileSystemStore implements the get/set interface using files, where a single file represents each key. A key is represented by the file name, and its value is stored as file data. Therefore, FileSystemStore imitates the get/set actions using simple file operations. Set is achieved using open-write-close, get using open-read-close and so on.

All files are concentrated under a single directory, whose name is hard coded. So actions such as "reset" are mapped to the deletion of all files under this directory, and iteration actions use file system APIs to traverse the directory.

Definition at line 42 of file FileSystemStore.h.

Member Typedef Documentation

◆ info_t

typedef struct mbed::KVStore::info info_t

inherited

Holds key information.

Constructor & Destructor Documentation

◆ FileSystemStore()

FileSystemStore ( FileSystem * fs )

Create FileSystemStore - A Key Value API on top of FS.

Parameters

fs	File system (FAT/LITTLE) on top of which FileSystemStore is adding KV API

◆ ~FileSystemStore()

virtual ~FileSystemStore ( )

virtual

Destroy FileSystemStore instance.

Definition at line 54 of file FileSystemStore.h.

Member Function Documentation

◆ init()

virtual int init ( )

virtual

Initialize FileSystemStore, checking validity of KVStore writing folder and if it doesn't exist, creating it.

Returns: MBED_SUCCESS Success. MBED_ERROR_FAILED_OPERATION Underlying file system failed operation.

Implements KVStore.

◆ deinit()

virtual int deinit ( )

virtual

Deinitialize FileSystemStore, release and free resources.

Returns: MBED_SUCCESS Success.

Implements KVStore.

◆ reset()

virtual int reset ( )

virtual

Reset FileSystemStore contents (clear all keys)

Returns: MBED_SUCCESS Success. MBED_ERROR_NOT_READY Not initialized. MBED_ERROR_FAILED_OPERATION Underlying file system failed operation.

Implements KVStore.

◆ set()

virtual int set	(	const char *	key,
		const void *	buffer,
		size_t	size,
		uint32_t	create_flags
	)

virtual

Set one FileSystemStore item, given key and value.

Parameters

[in]	key	Key - must not include '*' '/' '?' ':' ';' '\' '"' '\|' ' ' '<' '>' '\'.
[in]	buffer	Value data buffer.
[in]	size	Value data size.
[in]	create_flags	Flag mask.

Returns: MBED_SUCCESS Success. MBED_ERROR_NOT_READY Not initialized. MBED_ERROR_FAILED_OPERATION Underlying file system failed operation. MBED_ERROR_INVALID_ARGUMENT Invalid argument given in function arguments. MBED_ERROR_INVALID_SIZE Invalid size given in function arguments. MBED_ERROR_WRITE_PROTECTED Already stored with "write once" flag.

Implements KVStore.

◆ get()

virtual int get	(	const char *	key,
		void *	buffer,
		size_t	buffer_size,
		size_t *	actual_size = `NULL`,
		size_t	offset = `0`
	)

virtual

Get one FileSystemStore item by given key.

Parameters

[in]	key	Key - must not include '*' '/' '?' ':' ';' '\' '"' '\|' ' ' '<' '>' '\'.
[in]	buffer	Value data buffer.
[in]	buffer_size	Value data buffer size.
[out]	actual_size	Actual read size.
[in]	offset	Offset to read from in data.

Returns: MBED_SUCCESS Success. MBED_ERROR_NOT_READY Not initialized. MBED_ERROR_FAILED_OPERATION Underlying file system failed operation. MBED_ERROR_INVALID_ARGUMENT Invalid argument given in function arguments. MBED_ERROR_INVALID_SIZE Invalid size given in function arguments. MBED_ERROR_INVALID_DATA_DETECTED Data is corrupted. MBED_ERROR_ITEM_NOT_FOUND No such key.

Implements KVStore.

◆ get_info()

virtual int get_info	(	const char *	key,
		info_t *	info
	)

virtual

Get information of a given key.

The returned info contains size and flags

Parameters

[in]	key	Key - must not include '*' '/' '?' ':' ';' '\' '"' '\|' ' ' '<' '>' '\'.
[out]	info	Returned information structure.

Returns: MBED_SUCCESS Success. MBED_ERROR_NOT_READY Not initialized. MBED_ERROR_FAILED_OPERATION Underlying file system failed operation. MBED_ERROR_INVALID_ARGUMENT Invalid argument given in function arguments. MBED_ERROR_INVALID_SIZE Invalid size given in function arguments. MBED_ERROR_INVALID_DATA_DETECTED Data is corrupted. MBED_ERROR_ITEM_NOT_FOUND No such key.

Implements KVStore.

◆ remove()

virtual int remove ( const char * key )

virtual

Remove a FileSystemStore item by given key.

Parameters

[in] key Key - must not include '*' '/' '?' ':' ';' '\' '"' '|' ' ' '<' '>' '\'.

Returns: MBED_SUCCESS Success. MBED_ERROR_NOT_READY Not initialized. MBED_ERROR_FAILED_OPERATION Underlying file system failed operation. MBED_ERROR_INVALID_ARGUMENT Invalid argument given in function arguments. MBED_ERROR_ITEM_NOT_FOUND No such key. MBED_ERROR_WRITE_PROTECTED Already stored with "write once" flag.

Implements KVStore.

◆ set_start()

virtual int set_start	(	set_handle_t *	handle,
		const char *	key,
		size_t	final_data_size,
		uint32_t	create_flags
	)

virtual

Start an incremental FileSystemStore set sequence.

This operation is blocking other operations. Any get/set/remove/iterator operation will be blocked until set_finalize is called.

Parameters

[out]	handle	Returned incremental set handle.
[in]	key	Key - must not include '*' '/' '?' ':' ';' '\' '"' '\|' ' ' '<' '>' '\'.
[in]	final_data_size	Final value data size.
[in]	create_flags	Flag mask.

Returns: MBED_SUCCESS Success. MBED_ERROR_NOT_READY Not initialized. MBED_ERROR_FAILED_OPERATION Underlying file system failed operation. MBED_ERROR_INVALID_ARGUMENT Invalid argument given in function arguments. MBED_ERROR_INVALID_SIZE Invalid size given in function arguments. MBED_ERROR_WRITE_PROTECTED Already stored with "write once" flag.

Implements KVStore.

◆ set_add_data()

virtual int set_add_data	(	set_handle_t	handle,
		const void *	value_data,
		size_t	data_size
	)

virtual

Add data to incremental FileSystemStore set sequence.

This operation is blocking other operations. Any get/set/remove operation will be blocked until set_finalize is called.

Parameters

[in]	handle	Incremental set handle.
[in]	value_data	Value data to add.
[in]	data_size	Value data size.

Returns: MBED_SUCCESS Success. MBED_ERROR_NOT_READY Not initialized. MBED_ERROR_FAILED_OPERATION Underlying file system failed operation. MBED_ERROR_INVALID_ARGUMENT Invalid argument given in function arguments. MBED_ERROR_INVALID_SIZE Invalid size given in function arguments. MBED_ERROR_WRITE_PROTECTED Already stored with "write once" flag.

Implements KVStore.

◆ set_finalize()

virtual int set_finalize ( set_handle_t handle )

virtual

Finalize an incremental FileSystemStore set sequence.

Parameters

[in] handle Incremental set handle.

Returns: MBED_SUCCESS Success. MBED_ERROR_NOT_READY Not initialized. MBED_ERROR_FAILED_OPERATION Underlying file system failed operation. MBED_ERROR_INVALID_ARGUMENT Invalid argument given in function arguments.

Implements KVStore.

◆ iterator_open()

virtual int iterator_open	(	iterator_t *	it,
		const char *	prefix = `NULL`
	)

virtual

Start an iteration over FileSystemStore keys.

There are no issues with any other operations while iterator is open.

Parameters

[out]	it	Returned iterator handle.
[in]	prefix	Key prefix (null for all keys).

Returns: MBED_SUCCESS Success. MBED_ERROR_NOT_READY Not initialized. MBED_ERROR_INVALID_ARGUMENT Invalid argument given in function arguments.

Implements KVStore.

◆ iterator_next()

virtual int iterator_next	(	iterator_t	it,
		char *	key,
		size_t	key_size
	)

virtual

Get next key in iteration.

There are no issues with any other operations while iterator is open.

Parameters

[in]	it	Iterator handle.
[in]	key	Buffer for returned key.
[in]	key_size	Key buffer size.

Returns: MBED_SUCCESS Success. MBED_ERROR_NOT_READY Not initialized. MBED_ERROR_INVALID_ARGUMENT Invalid argument given in function arguments. MBED_ERROR_ITEM_NOT_FOUND No more keys found.

Implements KVStore.

◆ iterator_close()

virtual int iterator_close ( iterator_t it )

virtual

Close iteration.

Parameters

[in] it Iterator handle.

Returns: MBED_SUCCESS Success. MBED_ERROR_NOT_READY Not initialized. MBED_ERROR_INVALID_ARGUMENT Invalid argument given in function arguments.

Implements KVStore.

◆ is_valid_key()

bool is_valid_key ( const char * key ) const

inherited

Convenience function for checking key validity.

Key must not include '*' '/' '?' ':' ';' '\' '"' '|' ' ' '<' '>' '\'.

Parameters

[in] key Key buffer.

Returns: MBED_SUCCESS on success or an error code on failure

Definition at line 208 of file KVStore.h.

Public Types

Public Member Functions

Detailed Description

Member Typedef Documentation

◆ info_t

Constructor & Destructor Documentation

◆ FileSystemStore()

◆ ~FileSystemStore()

Member Function Documentation

◆ init()

◆ deinit()

◆ reset()

◆ set()

◆ get()

◆ get_info()

◆ remove()

◆ set_start()

◆ set_add_data()

◆ set_finalize()

◆ iterator_open()

◆ iterator_next()

◆ iterator_close()

◆ is_valid_key()