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Moved most on-disk definitions into lfs3.h

Browse Source 
Having on-disk definitions in one place is useful for referencing them
later, even if they aren't relevant for most API users.

.h files in C are already forced to expose a bunch of internal details
anyways, in order to provide struct size/alignment. Might as well
include on-disk information that would have even bigger consequences if
it changed.

Moved:

- Compat flag definitions
- Tag definitions
- DSIZEs and relevant encoding comments - Note some of these were
  already required to define lfs3_t
This commit is contained in:
Christopher Haster
2025-11-15 01:24:24 -06:00
parent 2d68db965b
commit 0f30021a0d
2 changed files with 287 additions and 279 deletions
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253
lfs3.c
View File

@ -1025,112 +1025,6 @@ static int lfs3_bd_cpyck(lfs3_t *lfs3,
/// Tags - lfs3_tag_t stuff ///
// 16-bit metadata tags
enum lfs3_tag {
// the null tag is reserved
LFS3_TAG_NULL = 0x0000,
// config tags
LFS3_TAG_CONFIG = 0x0000,
LFS3_TAG_MAGIC = 0x0031,
LFS3_TAG_VERSION = 0x0034,
LFS3_TAG_RCOMPAT = 0x0035,
LFS3_TAG_WCOMPAT = 0x0036,
LFS3_TAG_OCOMPAT = 0x0037,
LFS3_TAG_GEOMETRY = 0x0038,
LFS3_TAG_NAMELIMIT = 0x0039,
LFS3_TAG_FILELIMIT = 0x003a,
// in-device only, to help find unknown config tags
LFS3_TAG_UNKNOWNCONFIG = 0x003b,
// global-state tags
LFS3_TAG_GDELTA = 0x0100,
LFS3_TAG_GRMDELTA = 0x0100,
LFS3_TAG_GBMAPDELTA = 0x0104,
// name tags
LFS3_TAG_NAME = 0x0200,
LFS3_TAG_BNAME = 0x0200,
LFS3_TAG_REG = 0x0201,
LFS3_TAG_DIR = 0x0202,
LFS3_TAG_STICKYNOTE = 0x0203,
LFS3_TAG_BOOKMARK = 0x0204,
// in-device only name tags, these should never get written to disk
LFS3_TAG_ORPHAN = 0x0205,
LFS3_TAG_TRV = 0x0206,
LFS3_TAG_UNKNOWN = 0x0207,
// non-file name tags
LFS3_TAG_MNAME = 0x0220,
// struct tags
LFS3_TAG_STRUCT = 0x0300,
LFS3_TAG_BRANCH = 0x0300,
LFS3_TAG_DATA = 0x0304,
LFS3_TAG_BLOCK = 0x0308,
LFS3_TAG_DID = 0x0314,
LFS3_TAG_BSHRUB = 0x0318,
LFS3_TAG_BTREE = 0x031c,
LFS3_TAG_MROOT = 0x0321,
LFS3_TAG_MDIR = 0x0325,
LFS3_TAG_MTREE = 0x032c,
LFS3_TAG_BMRANGE = 0x0330,
LFS3_TAG_BMFREE = 0x0330,
LFS3_TAG_BMINUSE = 0x0331,
LFS3_TAG_BMERASED = 0x0332,
LFS3_TAG_BMBAD = 0x0333,
// user/sys attributes
LFS3_TAG_ATTR = 0x0400,
LFS3_TAG_UATTR = 0x0400,
LFS3_TAG_SATTR = 0x0500,
// shrub tags belong to secondary trees
LFS3_TAG_SHRUB = 0x1000,
// alt pointers form the inner nodes of our rbyd trees
LFS3_TAG_ALT = 0x4000,
LFS3_TAG_B = 0x0000,
LFS3_TAG_R = 0x2000,
LFS3_TAG_LE = 0x0000,
LFS3_TAG_GT = 0x1000,
// checksum tags
LFS3_TAG_CKSUM = 0x3000,
LFS3_TAG_PHASE = 0x0003,
LFS3_TAG_PERTURB = 0x0004,
LFS3_TAG_NOTE = 0x3100,
LFS3_TAG_ECKSUM = 0x3200,
LFS3_TAG_GCKSUMDELTA = 0x3300,
// in-device only tags, these should never get written to disk
LFS3_TAG_INTERNAL = 0x0800,
LFS3_TAG_RATTRS = 0x0800,
LFS3_TAG_SHRUBCOMMIT = 0x0801,
LFS3_TAG_GRMPUSH = 0x0802,
LFS3_TAG_MOVE = 0x0803,
LFS3_TAG_ATTRS = 0x0804,
// some in-device only tag modifiers
LFS3_TAG_RM = 0x8000,
LFS3_TAG_GROW = 0x4000,
LFS3_TAG_MASK0 = 0x0000,
LFS3_TAG_MASK2 = 0x1000,
LFS3_TAG_MASK8 = 0x2000,
LFS3_TAG_MASK12 = 0x3000,
};
// some other tag encodings with their own subfields
#define LFS3_TAG_ALT(c, d, key) \
(LFS3_TAG_ALT \
| (0x2000 & (c)) \
| (0x1000 & (d)) \
| (0x0fff & (lfs3_tag_t)(key)))
#define LFS3_TAG_ATTR(attr) \
(LFS3_TAG_ATTR \
| ((0x80 & (lfs3_tag_t)(attr)) << 1) \
| (0x7f & (lfs3_tag_t)(attr)))
// tag type operations
static inline lfs3_tag_t lfs3_tag_mode(lfs3_tag_t tag) {
return tag & 0xf000;
@ -1388,13 +1282,6 @@ static inline bool lfs3_tag_diverging2(
// support for encoding/decoding tags on disk
// tag encoding:
// .---+---+---+- -+- -+- -+- -+---+- -+- -+- -. tag: 1 be16 2 bytes
// | tag | weight | size | weight: 1 leb128 <=5 bytes
// '---+---+---+- -+- -+- -+- -+---+- -+- -+- -' size: 1 leb128 <=4 bytes
// total: <=11 bytes
#define LFS3_TAG_DSIZE (2+5+4)
// needed in lfs3_bd_readtag
#ifdef LFS3_CKMETAPARITY
static inline bool lfs3_m_isckparity(uint32_t flags);
@ -1932,13 +1819,6 @@ static int lfs3_bd_progdata(lfs3_t *lfs3,
// macros for le32/leb128/lleb128 encoding, these are useful for
// building rattrs
// le32 encoding:
// .---+---+---+---. total: 1 le32 4 bytes
// | le32 |
// '---+---+---+---'
//
#define LFS3_LE32_DSIZE 4
#ifndef LFS3_RDONLY
static inline lfs3_data_t lfs3_data_fromle32(uint32_t word,
uint8_t buffer[static LFS3_LE32_DSIZE]) {
@ -1947,13 +1827,6 @@ static inline lfs3_data_t lfs3_data_fromle32(uint32_t word,
}
#endif
// leb128 encoding:
// .---+- -+- -+- -+- -. total: 1 leb128 <=5 bytes
// | leb128 |
// '---+- -+- -+- -+- -'
//
#define LFS3_LEB128_DSIZE 5
#ifndef LFS3_RDONLY
static inline lfs3_data_t lfs3_data_fromleb128(uint32_t word,
uint8_t buffer[static LFS3_LEB128_DSIZE]) {
@ -1969,13 +1842,6 @@ static inline lfs3_data_t lfs3_data_fromleb128(uint32_t word,
}
#endif
// lleb128 encoding:
// .---+- -+- -+- -. total: 1 leb128 <=4 bytes
// | lleb128 |
// '---+- -+- -+- -'
//
#define LFS3_LLEB128_DSIZE 4
#ifndef LFS3_RDONLY
static inline lfs3_data_t lfs3_data_fromlleb128(uint32_t word,
uint8_t buffer[static LFS3_LLEB128_DSIZE]) {
@ -1992,6 +1858,8 @@ static inline lfs3_data_t lfs3_data_fromlleb128(uint32_t word,
#endif
/// Rattrs - lfs3_rattr_t stuff ///
// rattr layouts/lazy encoders
enum lfs3_from {
LFS3_FROM_BUF = 0,
@ -2009,85 +1877,6 @@ enum lfs3_from {
LFS3_FROM_GEOMETRY = 10,
};
// we need to at least define DSIZE/DATA macros here
// bptr encoding:
// .---+- -+- -+- -. size: 1 leb128 <=4 bytes
// | size | block: 1 leb128 <=5 bytes
// +---+- -+- -+- -+- -. off: 1 leb128 <=4 bytes
// | block | cksize: 1 leb128 <=4 bytes
// +---+- -+- -+- -+- -' cksum: 1 le32 4 bytes
// | off | total: <=21 bytes
// +---+- -+- -+- -+
// | cksize |
// +---+- -+- -+- -+
// | cksum |
// '---+---+---+---'
//
#define LFS3_BPTR_DSIZE (4+5+4+4+4)
// ecksum encoding:
// .---+- -+- -+- -. cksize: 1 leb128 <=4 bytes
// | cksize | cksum: 1 le32 4 bytes
// +---+- -+- -+- -+ total: <=8 bytes
// | cksum |
// '---+---+---+---'
//
#define LFS3_ECKSUM_DSIZE (4+4)
// branch encoding:
// .---+- -+- -+- -+- -. block: 1 leb128 <=5 bytes
// | block | trunk: 1 leb128 <=4 bytes
// +---+- -+- -+- -+- -' cksum: 1 le32 4 bytes
// | trunk | total: <=13 bytes
// +---+- -+- -+- -+
// | cksum |
// '---+---+---+---'
//
#define LFS3_BRANCH_DSIZE (5+4+4)
// btree encoding:
// .---+- -+- -+- -+- -. weight: 1 leb128 <=5 bytes
// | weight | block: 1 leb128 <=5 bytes
// +---+- -+- -+- -+- -+ trunk: 1 leb128 <=4 bytes
// | block | cksum: 1 le32 4 bytes
// +---+- -+- -+- -+- -' total: <=18 bytes
// | trunk |
// +---+- -+- -+- -+
// | cksum |
// '---+---+---+---'
//
#define LFS3_BTREE_DSIZE (5+LFS3_BRANCH_DSIZE)
// shrub encoding:
// .---+- -+- -+- -+- -. weight: 1 leb128 <=5 bytes
// | weight | trunk: 1 leb128 <=4 bytes
// +---+- -+- -+- -+- -' total: <=9 bytes
// | trunk |
// '---+- -+- -+- -'
//
#define LFS3_SHRUB_DSIZE (5+4)
// mptr encoding:
// .---+- -+- -+- -+- -. blocks: 2 leb128s <=2x5 bytes
// | block x 2 | total: <=10 bytes
// + +
// | |
// '---+- -+- -+- -+- -'
//
#define LFS3_MPTR_DSIZE (5+5)
// geometry encoding
// .---+- -+- -+- -. block_size: 1 leb128 <=4 bytes
// | block_size | block_count: 1 leb128 <=5 bytes
// +---+- -+- -+- -+- -. total: <=9 bytes
// | block_count |
// '---+- -+- -+- -+- -'
#define LFS3_GEOMETRY_DSIZE (4+5)
/// Rattrs - lfs3_rattr_t stuff ///
// operations on attribute lists
// our core attribute type
@ -15258,43 +15047,7 @@ static int lfs3_deinit(lfs3_t *lfs3) {
/// Mount/unmount ///
// compatibility flags
//
// - RCOMPAT => Must understand to read the filesystem
// - WCOMPAT => Must understand to write to the filesystem
// - OCOMPAT => No understanding necessary, we don't really use these
//
// note, "understanding" does not necessarily mean support
//
#define LFS3_RCOMPAT_NONSTANDARD 0x00000001 // Non-standard filesystem format
#define LFS3_RCOMPAT_WRONLY 0x00000004 // Reading is disallowed
#define LFS3_RCOMPAT_MMOSS 0x00000010 // May use an inlined mdir
#define LFS3_RCOMPAT_MSPROUT 0x00000020 // May use an mdir pointer
#define LFS3_RCOMPAT_MSHRUB 0x00000040 // May use an inlined mtree
#define LFS3_RCOMPAT_MTREE 0x00000080 // May use an mtree
#define LFS3_RCOMPAT_BMOSS 0x00000100 // Files may use inlined data
#define LFS3_RCOMPAT_BSPROUT 0x00000200 // Files may use block pointers
#define LFS3_RCOMPAT_BSHRUB 0x00000400 // Files may use inlined btrees
#define LFS3_RCOMPAT_BTREE 0x00000800 // Files may use btrees
#define LFS3_RCOMPAT_GRM 0x00010000 // Global-remove in use
// internal
#define LFS3_rcompat_OVERFLOW 0x80000000 // Can't represent all flags
#define LFS3_WCOMPAT_NONSTANDARD 0x00000001 // Non-standard filesystem format
#define LFS3_WCOMPAT_RDONLY 0x00000002 // Writing is disallowed
#define LFS3_WCOMPAT_GCKSUM 0x00040000 // Global-checksum in use
#define LFS3_WCOMPAT_GBMAP 0x00080000 // Global on-disk block-map in use
#define LFS3_WCOMPAT_DIR 0x01000000 // Directory files in use
// internal
#define LFS3_wcompat_OVERFLOW 0x80000000 // Can't represent all flags
#define LFS3_OCOMPAT_NONSTANDARD 0x00000001 // Non-standard filesystem format
// internal
#define LFS3_ocompat_OVERFLOW 0x80000000 // Can't represent all flags
typedef uint32_t lfs3_rcompat_t;
typedef uint32_t lfs3_wcompat_t;
typedef uint32_t lfs3_ocompat_t;
// compat flags things
static inline bool lfs3_wcompat_isgbmap(lfs3_wcompat_t flags) {
return flags & LFS3_WCOMPAT_GBMAP;

313
lfs3.h
View File

@ -55,6 +55,10 @@ typedef int32_t lfs3_smid_t;
typedef uint32_t lfs3_did_t;
typedef int32_t lfs3_sdid_t;
typedef uint32_t lfs3_rcompat_t;
typedef uint32_t lfs3_wcompat_t;
typedef uint32_t lfs3_ocompat_t;
// Maximum name size in bytes, may be redefined to reduce the size of the
// info struct. Limited to <= 1022. Stored in superblock and must be
// respected by other littlefs drivers.
@ -314,7 +318,6 @@ enum lfs3_type {
#define LFS3_I_CKMETA 0x00010000 // Metadata checksums not checked recently
#define LFS3_I_CKDATA 0x00020000 // Data checksums not checked recently
// Block types
enum lfs3_btype {
LFS3_BTYPE_MDIR = 1,
@ -724,7 +727,283 @@ struct lfs3_file_cfg {
};
/// internal littlefs data structures ///
/// On-disk things ///
// On-disk metadata tags
enum lfs3_tag {
// the null tag is reserved
LFS3_TAG_NULL = 0x0000,
// config tags
LFS3_TAG_CONFIG = 0x0000,
LFS3_TAG_MAGIC = 0x0031,
LFS3_TAG_VERSION = 0x0034,
LFS3_TAG_RCOMPAT = 0x0035,
LFS3_TAG_WCOMPAT = 0x0036,
LFS3_TAG_OCOMPAT = 0x0037,
LFS3_TAG_GEOMETRY = 0x0038,
LFS3_TAG_NAMELIMIT = 0x0039,
LFS3_TAG_FILELIMIT = 0x003a,
// in-device only, to help find unknown config tags
LFS3_TAG_UNKNOWNCONFIG = 0x003b,
// global-state tags
LFS3_TAG_GDELTA = 0x0100,
LFS3_TAG_GRMDELTA = 0x0100,
LFS3_TAG_GBMAPDELTA = 0x0104,
// name tags
LFS3_TAG_NAME = 0x0200,
LFS3_TAG_BNAME = 0x0200,
LFS3_TAG_REG = 0x0201,
LFS3_TAG_DIR = 0x0202,
LFS3_TAG_STICKYNOTE = 0x0203,
LFS3_TAG_BOOKMARK = 0x0204,
// in-device only name tags, these should never get written to disk
LFS3_TAG_ORPHAN = 0x0205,
LFS3_TAG_TRV = 0x0206,
LFS3_TAG_UNKNOWN = 0x0207,
// non-file name tags
LFS3_TAG_MNAME = 0x0220,
// struct tags
LFS3_TAG_STRUCT = 0x0300,
LFS3_TAG_BRANCH = 0x0300,
LFS3_TAG_DATA = 0x0304,
LFS3_TAG_BLOCK = 0x0308,
LFS3_TAG_DID = 0x0314,
LFS3_TAG_BSHRUB = 0x0318,
LFS3_TAG_BTREE = 0x031c,
LFS3_TAG_MROOT = 0x0321,
LFS3_TAG_MDIR = 0x0325,
LFS3_TAG_MTREE = 0x032c,
LFS3_TAG_BMRANGE = 0x0330,
LFS3_TAG_BMFREE = 0x0330,
LFS3_TAG_BMINUSE = 0x0331,
LFS3_TAG_BMERASED = 0x0332,
LFS3_TAG_BMBAD = 0x0333,
// user/sys attributes
LFS3_TAG_ATTR = 0x0400,
LFS3_TAG_UATTR = 0x0400,
LFS3_TAG_SATTR = 0x0500,
// shrub tags belong to secondary trees
LFS3_TAG_SHRUB = 0x1000,
// alt pointers form the inner nodes of our rbyd trees
LFS3_TAG_ALT = 0x4000,
LFS3_TAG_B = 0x0000,
LFS3_TAG_R = 0x2000,
LFS3_TAG_LE = 0x0000,
LFS3_TAG_GT = 0x1000,
// checksum tags
LFS3_TAG_CKSUM = 0x3000,
LFS3_TAG_PHASE = 0x0003,
LFS3_TAG_PERTURB = 0x0004,
LFS3_TAG_NOTE = 0x3100,
LFS3_TAG_ECKSUM = 0x3200,
LFS3_TAG_GCKSUMDELTA = 0x3300,
// in-device only tags, these should never get written to disk
LFS3_TAG_INTERNAL = 0x0800,
LFS3_TAG_RATTRS = 0x0800,
LFS3_TAG_SHRUBCOMMIT = 0x0801,
LFS3_TAG_GRMPUSH = 0x0802,
LFS3_TAG_MOVE = 0x0803,
LFS3_TAG_ATTRS = 0x0804,
// some in-device only tag modifiers
LFS3_TAG_RM = 0x8000,
LFS3_TAG_GROW = 0x4000,
LFS3_TAG_MASK0 = 0x0000,
LFS3_TAG_MASK2 = 0x1000,
LFS3_TAG_MASK8 = 0x2000,
LFS3_TAG_MASK12 = 0x3000,
};
// some other tag encodings with their own subfields
#define LFS3_TAG_ALT(c, d, key) \
(LFS3_TAG_ALT \
| (0x2000 & (c)) \
| (0x1000 & (d)) \
| (0x0fff & (lfs3_tag_t)(key)))
#define LFS3_TAG_ATTR(attr) \
(LFS3_TAG_ATTR \
| ((0x80 & (lfs3_tag_t)(attr)) << 1) \
| (0x7f & (lfs3_tag_t)(attr)))
// On-disk compat flags
//
// - RCOMPAT => Must understand to read the filesystem
// - WCOMPAT => Must understand to write to the filesystem
// - OCOMPAT => No understanding necessary, we don't really use these
//
// note, "understanding" does not necessarily mean support
//
#define LFS3_RCOMPAT_NONSTANDARD 0x00000001 // Non-standard filesystem format
#define LFS3_RCOMPAT_WRONLY 0x00000004 // Reading is disallowed
#define LFS3_RCOMPAT_MMOSS 0x00000010 // May use an inlined mdir
#define LFS3_RCOMPAT_MSPROUT 0x00000020 // May use an mdir pointer
#define LFS3_RCOMPAT_MSHRUB 0x00000040 // May use an inlined mtree
#define LFS3_RCOMPAT_MTREE 0x00000080 // May use an mtree
#define LFS3_RCOMPAT_BMOSS 0x00000100 // Files may use inlined data
#define LFS3_RCOMPAT_BSPROUT 0x00000200 // Files may use block pointers
#define LFS3_RCOMPAT_BSHRUB 0x00000400 // Files may use inlined btrees
#define LFS3_RCOMPAT_BTREE 0x00000800 // Files may use btrees
#define LFS3_RCOMPAT_GRM 0x00010000 // Global-remove in use
// internally used flags
#define LFS3_rcompat_OVERFLOW 0x80000000 // Can't represent all flags
#define LFS3_WCOMPAT_NONSTANDARD 0x00000001 // Non-standard filesystem format
#define LFS3_WCOMPAT_RDONLY 0x00000002 // Writing is disallowed
#define LFS3_WCOMPAT_GCKSUM 0x00040000 // Global-checksum in use
#define LFS3_WCOMPAT_GBMAP 0x00080000 // Global on-disk block-map in use
#define LFS3_WCOMPAT_DIR 0x01000000 // Directory files in use
// internally used flags
#define LFS3_wcompat_OVERFLOW 0x80000000 // Can't represent all flags
#define LFS3_OCOMPAT_NONSTANDARD 0x00000001 // Non-standard filesystem format
// internally used flags
#define LFS3_ocompat_OVERFLOW 0x80000000 // Can't represent all flags
// On-disk encodings/decodings
// tag encoding:
// .---+---+---+- -+- -+- -+- -+---+- -+- -+- -. tag: 1 be16 2 bytes
// | tag | weight | size | weight: 1 leb128 <=5 bytes
// '---+---+---+- -+- -+- -+- -+---+- -+- -+- -' size: 1 leb128 <=4 bytes
// total: <=11 bytes
#define LFS3_TAG_DSIZE (2+5+4)
// le32 encoding:
// .---+---+---+---. total: 1 le32 4 bytes
// | le32 |
// '---+---+---+---'
//
#define LFS3_LE32_DSIZE 4
// leb128 encoding:
// .---+- -+- -+- -+- -. total: 1 leb128 <=5 bytes
// | leb128 |
// '---+- -+- -+- -+- -'
//
#define LFS3_LEB128_DSIZE 5
// lleb128 encoding:
// .---+- -+- -+- -. total: 1 leb128 <=4 bytes
// | lleb128 |
// '---+- -+- -+- -'
//
#define LFS3_LLEB128_DSIZE 4
// geometry encoding
// .---+- -+- -+- -. block_size: 1 leb128 <=4 bytes
// | block_size | block_count: 1 leb128 <=5 bytes
// +---+- -+- -+- -+- -. total: <=9 bytes
// | block_count |
// '---+- -+- -+- -+- -'
//
#define LFS3_GEOMETRY_DSIZE (4+5)
// grm encoding:
// .- -+- -+- -+- -+- -. mids: 2 leb128s <=2x5 bytes
// ' mids ' total: <=10 bytes
// + +
// ' '
// '- -+- -+- -+- -+- -'
//
#define LFS3_GRM_DSIZE (5+5)
// gbmap encoding:
// .---+- -+- -+- -+- -. window: 1 leb128 <=5 bytes
// | window | known: 1 leb128 <=5 bytes
// +---+- -+- -+- -+- -+ block: 1 leb128 <=5 bytes
// | known | trunk: 1 leb128 <=4 bytes
// +---+- -+- -+- -+- -+ cksum: 1 le32 4 bytes
// | block | total: 23 bytes
// +---+- -+- -+- -+- -'
// | trunk |
// +---+- -+- -+- -+
// | cksum |
// '---+---+---+---'
//
#define LFS3_GBMAP_DSIZE (5+5+5+4+4)
// branch encoding:
// .---+- -+- -+- -+- -. block: 1 leb128 <=5 bytes
// | block | trunk: 1 leb128 <=4 bytes
// +---+- -+- -+- -+- -' cksum: 1 le32 4 bytes
// | trunk | total: <=13 bytes
// +---+- -+- -+- -+
// | cksum |
// '---+---+---+---'
//
#define LFS3_BRANCH_DSIZE (5+4+4)
// bptr encoding:
// .---+- -+- -+- -. size: 1 leb128 <=4 bytes
// | size | block: 1 leb128 <=5 bytes
// +---+- -+- -+- -+- -. off: 1 leb128 <=4 bytes
// | block | cksize: 1 leb128 <=4 bytes
// +---+- -+- -+- -+- -' cksum: 1 le32 4 bytes
// | off | total: <=21 bytes
// +---+- -+- -+- -+
// | cksize |
// +---+- -+- -+- -+
// | cksum |
// '---+---+---+---'
//
#define LFS3_BPTR_DSIZE (4+5+4+4+4)
// btree encoding:
// .---+- -+- -+- -+- -. weight: 1 leb128 <=5 bytes
// | weight | block: 1 leb128 <=5 bytes
// +---+- -+- -+- -+- -+ trunk: 1 leb128 <=4 bytes
// | block | cksum: 1 le32 4 bytes
// +---+- -+- -+- -+- -' total: <=18 bytes
// | trunk |
// +---+- -+- -+- -+
// | cksum |
// '---+---+---+---'
//
#define LFS3_BTREE_DSIZE (5+LFS3_BRANCH_DSIZE)
// shrub encoding:
// .---+- -+- -+- -+- -. weight: 1 leb128 <=5 bytes
// | weight | trunk: 1 leb128 <=4 bytes
// +---+- -+- -+- -+- -' total: <=9 bytes
// | trunk |
// '---+- -+- -+- -'
//
#define LFS3_SHRUB_DSIZE (5+4)
// mptr encoding:
// .---+- -+- -+- -+- -. blocks: 2 leb128s <=2x5 bytes
// | block x 2 | total: <=10 bytes
// + +
// | |
// '---+- -+- -+- -+- -'
//
#define LFS3_MPTR_DSIZE (5+5)
// ecksum encoding:
// .---+- -+- -+- -. cksize: 1 leb128 <=4 bytes
// | cksize | cksum: 1 le32 4 bytes
// +---+- -+- -+- -+ total: <=8 bytes
// | cksum |
// '---+---+---+---'
//
#define LFS3_ECKSUM_DSIZE (4+4)
/// Internal littlefs structs ///
// either an on-disk or in-RAM data pointer
//
@ -917,34 +1196,10 @@ typedef struct lfs3_trv {
} lfs3_trv_t;
// littlefs global state
// grm encoding:
// .- -+- -+- -+- -+- -. mids: 2 leb128s <=2x5 bytes
// ' mids ' total: <=10 bytes
// + +
// ' '
// '- -+- -+- -+- -+- -'
//
#define LFS3_GRM_DSIZE (5+5)
typedef struct lfs3_grm {
lfs3_smid_t queue[2];
} lfs3_grm_t;
// gbmap encoding:
// .---+- -+- -+- -+- -. window: 1 leb128 <=5 bytes
// | window | known: 1 leb128 <=5 bytes
// +---+- -+- -+- -+- -+ block: 1 leb128 <=5 bytes
// | known | trunk: 1 leb128 <=4 bytes
// +---+- -+- -+- -+- -+ cksum: 1 le32 4 bytes
// | block | total: 23 bytes
// +---+- -+- -+- -+- -'
// | trunk |
// +---+- -+- -+- -+
// | cksum |
// '---+---+---+---'
#define LFS3_GBMAP_DSIZE (5+5+5+4+4)
typedef struct lfs3_gbmap {
lfs3_block_t window;
lfs3_block_t known;
@ -990,15 +1245,14 @@ typedef struct lfs3 {
} pcache;
// optional prog-aligned cksum
uint32_t pcksum;
#endif
#if !defined(LFS3_RDONLY) && defined(LFS3_CKMETAPARITY)
#ifdef LFS3_CKMETAPARITY
struct {
lfs3_block_t block;
// sign(off) => tail parity
lfs3_size_t off;
} ptail;
#endif
#endif
#ifndef LFS3_RDONLY
struct lfs3_lookahead {
@ -1043,6 +1297,7 @@ typedef struct lfs3 {
} lfs3_t;
/// Filesystem functions ///
// Format a block device with the littlefs