RingFS API

Data Structures
struct	ringfs_flash_partition
	Flash memory+parition descriptor. More...
struct	ringfs
	RingFS instance. More...

Functions
int	ringfs_init (struct ringfs *fs, const struct ringfs_flash_partition *flash, uint32_t version, int object_size)
	Initialize a RingFS instance. More...
int	ringfs_format (struct ringfs *fs)
	Format the flash memory. More...
int	ringfs_scan (struct ringfs *fs)
	Scan the flash memory for a valid filesystem. More...
int	ringfs_capacity (struct ringfs *fs)
	Calculate maximum RingFS capacity. More...
int	ringfs_count_estimate (struct ringfs *fs)
	Calculate approximate object count. More...
int	ringfs_count_exact (struct ringfs *fs)
	Calculate exact object count. More...
int	ringfs_append (struct ringfs *fs, const void *object)
	Append an object at the end of the ring. More...
int	ringfs_fetch (struct ringfs *fs, void *object)
	Fetch next object from the ring, oldest-first. More...
int	ringfs_discard (struct ringfs *fs)
	Discard all fetched objects up to the read cursor. More...
int	ringfs_rewind (struct ringfs *fs)
	Rewind the read cursor back to the oldest object. More...

Detailed Description

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Data Structure Documentation

struct ringfs

RingFS instance.

Should be initialized with ringfs_init() befure use. Structure fields should not be accessed directly.

Definition at line 63 of file ringfs.h.

Data Fields
struct ringfs_loc	cursor
const struct ringfs_flash_partition *	flash
int	object_size
struct ringfs_loc	read
int	slots_per_sector
uint32_t	version
struct ringfs_loc	write

Function Documentation

int ringfs_append	(	struct ringfs *	fs,
		const void *	object
	)

Append an object at the end of the ring.

Deletes oldest objects as needed.

Parameters

fs	Initialized RingFS instance.
object	Object to be stored.

Returns

Zero on success, -1 on failure.

Definition at line 310 of file ringfs.c.

int ringfs_capacity

(

struct ringfs *

fs

)

Calculate maximum RingFS capacity.

Parameters

fs	Initialized RingFS instance.

Returns

Maximum capacity on success, -1 on failure.

Definition at line 278 of file ringfs.c.

int ringfs_count_estimate

(

struct ringfs *

fs

)

Calculate approximate object count.

Runs in O(1).

Parameters

fs	Initialized RingFS instance.

Returns

Estimated object count on success, -1 on failure.

Definition at line 283 of file ringfs.c.

int ringfs_count_exact

(

struct ringfs *

fs

)

Calculate exact object count.

Runs in O(n).

Parameters

fs	Initialized RingFS instance.

Returns

Exact object count on success, -1 on failure.

Definition at line 291 of file ringfs.c.

int ringfs_discard

(

struct ringfs *

fs

)

Discard all fetched objects up to the read cursor.

Parameters

fs	Initialized RingFS instance.

Returns

Zero on success, -1 on failure.

Definition at line 384 of file ringfs.c.

int ringfs_fetch	(	struct ringfs *	fs,
		void *	object
	)

Fetch next object from the ring, oldest-first.

Advances read cursor.

Parameters

fs	Initialized RingFS instance.
object	Buffer to store retrieved object.

Returns

Zero on success, -1 on failure.

Definition at line 363 of file ringfs.c.

int ringfs_format

(

struct ringfs *

fs

)

Format the flash memory.

Parameters

fs	Initialized RingFS instance.

Returns

Zero on success, -1 on failure.

Definition at line 153 of file ringfs.c.

int ringfs_init	(	struct ringfs *	fs,
		const struct ringfs_flash_partition *	flash,
		uint32_t	version,
		int	object_size
	)

Initialize a RingFS instance.

Must be called before the instance can be used with the other ringfs_* functions.

Parameters

fs	RingFS instance to be initialized.
flash	Flash memory interface. Must be implemented externally.
version	Object version. Should be incremented whenever the object's semantics or size change in a backwards-incompatible way.
object_size	Size of one stored object, in bytes.

Returns

Zero on success, -1 on failure.

Definition at line 139 of file ringfs.c.

int ringfs_rewind

(

struct ringfs *

fs

)

Rewind the read cursor back to the oldest object.

Parameters

fs	Initialized RingFS instance.

Returns

Zero on success, -1 on failure.

Definition at line 394 of file ringfs.c.

int ringfs_scan

(

struct ringfs *

fs

)

Scan the flash memory for a valid filesystem.

Parameters

fs	Initialized RingFS instance.

Returns

Zero on success, -1 on failure.

Definition at line 174 of file ringfs.c.