Tiny Database Storage (TDBStore) is a lightweight module that stores data on flash storage. More...

#include <TDBStore.h>

Inheritance diagram for TDBStore:

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

Public Member Functions
	TDBStore (BlockDevice *bd)
	Class constructor. More...

virtual	~TDBStore ()
	Class destructor. More...

virtual int	init ()
	Initialize TDBStore. More...

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

virtual int	reset ()
	Reset TDBStore contents (clear all keys) and reserved data. More...

virtual int	set (const char key, const void buffer, size_t size, uint32_t create_flags)
	Set one TDBStore 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 TDBStore 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 TDBStore 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 TDBStore set sequence. More...

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

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

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

virtual int	reserved_data_set (const void *reserved_data, size_t reserved_data_buf_size)
	Set data in reserved area, which is a special location for special data, such as ROT. More...

virtual int	reserved_data_get (void reserved_data, size_t reserved_data_buf_size, size_t actual_data_size=0)
	Get data from reserved area, which is a special location for special data, such as ROT. More...

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

Detailed Description

Tiny Database Storage (TDBStore) is a lightweight module that stores data on flash storage.

It is part of of the KVStore class family, meaning it supports the get/set interface. It is designed to optimize performance (speed of access), reduce wearing of the flash and minimize storage overhead. It is also resilient to power failures.

TDBStore assumes the underlying block device is fully dedicated to it (starting offset 0). If you want to dedicate only a part of the device to TDBStore, use a sliced block device, typically with SlicingBlockDevice.

Definition at line 45 of file TDBStore.h.

Member Typedef Documentation

◆ info_t

typedef struct mbed::KVStore::info info_t

inherited

Holds key information.

Constructor & Destructor Documentation

◆ TDBStore()

TDBStore ( BlockDevice * bd )

Class constructor.

Parameters

[in] bd Underlying block device.

◆ ~TDBStore()

virtual ~TDBStore ( )

virtual

Class destructor.

Member Function Documentation

◆ init()

virtual int init ( )

virtual

Initialize TDBStore.

If data exists, TDBStore will check the data integrity on initialize. If the integrity checks fails, the TDBStore will use GC to collect the available data and clean corrupted and erroneous records.

Returns: MBED_SUCCESS Success.; Negative error code on failure.

Implements KVStore.

◆ deinit()

virtual int deinit ( )

virtual

Deinitialize TDBStore, release and free resources.

Returns: MBED_SUCCESS Success.

Implements KVStore.

◆ reset()

virtual int reset ( )

virtual

Reset TDBStore contents (clear all keys) and reserved data.

Returns: MBED_SUCCESS Success. MBED_ERROR_NOT_READY Not initialized. MBED_ERROR_READ_FAILED Unable to read from media. MBED_ERROR_WRITE_FAILED Unable to write to media.

Implements KVStore.

◆ set()

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

virtual

Set one TDBStore 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_READ_FAILED Unable to read from media. MBED_ERROR_WRITE_FAILED Unable to write to media. MBED_ERROR_INVALID_ARGUMENT Invalid argument given in function arguments. MBED_ERROR_INVALID_SIZE Invalid size given in function arguments. MBED_ERROR_MEDIA_FULL Not enough room on media. 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 TDBStore 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_READ_FAILED Unable to read from media. 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 corrupt. 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_READ_FAILED Unable to read from media. MBED_ERROR_INVALID_ARGUMENT Invalid argument given in function arguments. MBED_ERROR_INVALID_DATA_DETECTED Data is corrupt. MBED_ERROR_ITEM_NOT_FOUND No such key.

Implements KVStore.

◆ remove()

virtual int remove ( const char * key )

virtual

Remove a TDBStore item by given key.

Parameters

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

Returns: MBED_SUCCESS Success. MBED_ERROR_NOT_READY Not initialized. MBED_ERROR_READ_FAILED Unable to read from media. MBED_ERROR_WRITE_FAILED Unable to write to media. MBED_ERROR_INVALID_ARGUMENT Invalid argument given in function arguments. MBED_ERROR_MEDIA_FULL Not enough room on media. 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 TDBStore 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_READ_FAILED Unable to read from media. MBED_ERROR_WRITE_FAILED Unable to write to media. MBED_ERROR_INVALID_ARGUMENT Invalid argument given in function arguments. MBED_ERROR_INVALID_SIZE Invalid size given in function arguments. MBED_ERROR_MEDIA_FULL Not enough room on media. 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 TDBStore set sequence.

This operation is blocking other operations. Any get/set/remove operation will be blocked until set_finalize will be 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_WRITE_FAILED Unable to write to media. MBED_ERROR_INVALID_ARGUMENT Invalid argument given in function arguments. MBED_ERROR_INVALID_SIZE Invalid size given in function arguments.

Implements KVStore.

◆ set_finalize()

virtual int set_finalize ( set_handle_t handle )

virtual

Finalize an incremental KVStore set sequence.

Parameters

[in] handle Incremental set handle.

Returns: MBED_SUCCESS Success. MBED_ERROR_NOT_READY Not initialized. MBED_ERROR_WRITE_FAILED Unable to write to media. 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 KVStore 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_READ_FAILED Unable to read from block device. 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 corrupt. 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.

◆ reserved_data_set()

virtual int reserved_data_set	(	const void *	reserved_data,
		size_t	reserved_data_buf_size
	)

virtual

Set data in reserved area, which is a special location for special data, such as ROT.

The data written to reserved area can't be overwritten.

Parameters

[in]	reserved_data	Reserved data buffer.
[in]	reserved_data_buf_size	Reserved data buffer size.

Returns: MBED_SUCCESS Success. MBED_ERROR_NOT_READY Not initialized. MBED_ERROR_READ_FAILED Unable to read from media. MBED_ERROR_WRITE_FAILED Unable to write to media. MBED_ERROR_INVALID_ARGUMENT Invalid argument given in function arguments. MBED_ERROR_INVALID_SIZE Invalid size given in function arguments.

◆ reserved_data_get()

virtual int reserved_data_get	(	void *	reserved_data,
		size_t	reserved_data_buf_size,
		size_t *	actual_data_size = `0`
	)

virtual

Get data from reserved area, which is a special location for special data, such as ROT.

Parameters

[in]	reserved_data	Reserved data buffer.
[in]	reserved_data_buf_size	Reserved data buffer size.
[in]	actual_data_size	Return data size.

Returns: MBED_SUCCESS Success. MBED_ERROR_NOT_READY Not initialized. MBED_ERROR_READ_FAILED Unable to read from media. MBED_ERROR_INVALID_ARGUMENT Invalid argument given in function arguments. MBED_ERROR_INVALID_DATA_DETECTED Data is corrupt. MBED_ERROR_ITEM_NOT_FOUND No reserved data was written.

◆ 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

◆ TDBStore()

◆ ~TDBStore()

Member Function Documentation

◆ init()

◆ deinit()

◆ reset()

◆ set()

◆ get()

◆ get_info()

◆ remove()

◆ set_start()

◆ set_add_data()

◆ set_finalize()

◆ iterator_open()

◆ iterator_next()

◆ iterator_close()

◆ reserved_data_set()

◆ reserved_data_get()

◆ is_valid_key()