Files
thirdparty-littlefs/lfs.h
Christopher Haster ed674e8414 Added support for the basic file operation
Missing seek, but these are the core filesystem operations
provided by this filesystem:
- Read a file
- Append to a file

Additional work is needed around freeing the previous file, so
right now it's limited to appending to existing files, a real
append only filesystem. Unfortunately the overhead of the free
list with multiple open files is becoming tricky.
2017-03-19 22:25:36 -05:00

135 lines
2.7 KiB
C

/*
* The little filesystem
*
* Copyright (c) 2017 Christopher Haster
* Distributed under the MIT license
*/
#ifndef LFS_H
#define LFS_H
#include "lfs_config.h"
#include "lfs_bd.h"
// Data structures
enum lfs_error {
LFS_ERROR_OK = 0,
LFS_ERROR_CORRUPT = -3,
LFS_ERROR_NO_ENTRY = -4,
LFS_ERROR_EXISTS = -5,
LFS_ERROR_NOT_DIR = -6,
LFS_ERROR_INVALID = -7,
};
enum lfs_type {
LFS_TYPE_REG = 1,
LFS_TYPE_DIR = 2,
};
enum lfs_open_flags {
LFS_O_RDONLY = 0,
LFS_O_WRONLY = 1,
LFS_O_RDWR = 2,
LFS_O_CREAT = 0x0040,
LFS_O_EXCL = 0x0080,
LFS_O_TRUNC = 0x0200,
LFS_O_APPEND = 0x0400,
LFS_O_SYNC = 0x1000,
};
typedef struct lfs_free {
lfs_word_t begin;
lfs_word_t off;
lfs_word_t end;
lfs_disk_struct lfs_disk_free {
lfs_word_t rev;
lfs_ino_t head;
lfs_word_t off;
lfs_word_t end;
} d;
} lfs_free_t;
typedef struct lfs_dir {
lfs_ino_t pair[2];
lfs_off_t i;
lfs_disk_struct lfs_disk_dir {
lfs_word_t rev;
lfs_size_t size;
lfs_ino_t tail[2];
struct lfs_disk_free free;
} d;
} lfs_dir_t;
typedef struct lfs_entry {
lfs_ino_t dir[2];
lfs_off_t off;
lfs_disk_struct lfs_disk_entry {
uint16_t type;
uint16_t len;
union {
lfs_disk_struct {
lfs_ino_t head;
lfs_size_t size;
} file;
lfs_ino_t dir[2];
} u;
} d;
} lfs_entry_t;
typedef struct lfs_file {
lfs_ino_t head;
lfs_size_t size;
lfs_ino_t wblock;
lfs_word_t windex;
lfs_ino_t rblock;
lfs_word_t rindex;
lfs_off_t roff;
struct lfs_entry entry;
} lfs_file_t;
typedef struct lfs_superblock {
lfs_ino_t pair[2];
lfs_disk_struct lfs_disk_superblock {
lfs_word_t rev;
uint32_t size;
lfs_ino_t root[2];
char magic[8];
uint32_t block_size;
uint32_t block_count;
} d;
} lfs_superblock_t;
// Little filesystem type
typedef struct lfs {
lfs_bd_t *bd;
const struct lfs_bd_ops *ops;
lfs_ino_t cwd[2];
lfs_free_t free;
struct lfs_bd_info info;
} lfs_t;
// Functions
lfs_error_t lfs_create(lfs_t *lfs, lfs_bd_t *bd, const struct lfs_bd_ops *bd_ops);
lfs_error_t lfs_format(lfs_t *lfs);
lfs_error_t lfs_mount(lfs_t *lfs);
lfs_error_t lfs_mkdir(lfs_t *lfs, const char *path);
lfs_error_t lfs_file_open(lfs_t *lfs, lfs_file_t *file,
const char *path, int flags);
lfs_error_t lfs_file_close(lfs_t *lfs, lfs_file_t *file);
lfs_ssize_t lfs_file_write(lfs_t *lfs, lfs_file_t *file,
const void *buffer, lfs_size_t size);
lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,
void *buffer, lfs_size_t size);
#endif