Struct littlefs2::fs::File

pub struct File<'a, 'b, S: Storage> { /* fields omitted */ }

Implementations

impl<'a, 'b, Storage: Storage> File<'a, 'b, Storage>

pub fn allocate() -> FileAllocation<Storage>

pub fn with_options() -> OpenOptions

Returns a new OpenOptions object.

This function returns a new OpenOptions object that you can use to open or create a file with specific options if open() or create() are not appropriate.

It is equivalent to OpenOptions::new() but allows you to write more readable code. This also avoids the need to import OpenOptions`.

pub unsafe fn open(
    fs: &'b Filesystem<'a, Storage>,
    alloc: &'b mut FileAllocation<Storage>,
    path: &Path
) -> Result<Self>

pub fn open_and_then<R>(
    fs: &Filesystem<'a, Storage>,
    path: &Path,
    f: impl FnOnce(&File<'_, '_, Storage>) -> Result<R>
) -> Result<R>

pub unsafe fn create(
    fs: &'b Filesystem<'a, Storage>,
    alloc: &'b mut FileAllocation<Storage>,
    path: &Path
) -> Result<Self>

pub fn create_and_then<R>(
    fs: &Filesystem<'a, Storage>,
    path: &Path,
    f: impl FnOnce(&File<'_, '_, Storage>) -> Result<R>
) -> Result<R>

pub unsafe fn borrow_filesystem<'c>(&'c mut self) -> &'c Filesystem<'a, Storage>

pub unsafe fn close(self) -> Result<()>

Sync the file and drop it from the internal linked list. Not doing this is UB, which is why we have all the closure-based APIs.

TODO: check if this can be closed >1 times, if so make it safe

Update: It seems like there’s an assertion on a flag called LFS_F_OPENED: https://github.com/ARMmbed/littlefs/blob/4c9146ea539f72749d6cc3ea076372a81b12cb11/lfs.c#L2549 https://github.com/ARMmbed/littlefs/blob/4c9146ea539f72749d6cc3ea076372a81b12cb11/lfs.c#L2566

• On second call, shouldn’t find ourselves in the “mlist of mdirs”
• Since we don’t have dynamically allocated buffers, at least we don’t hit the double-free.
• Not sure what happens in lfs_file_sync, but it should be easy to just error on not LFS_F_OPENED…

pub fn sync(&self) -> Result<()>

Synchronize file contents to storage.

pub fn len(&self) -> Result<usize>

Size of the file in bytes.

pub fn set_len(&self, size: usize) -> Result<()>

Truncates or extends the underlying file, updating the size of this file to become size.

If the size is less than the current file’s size, then the file will be shrunk. If it is greater than the current file’s size, then the file will be extended to size and have all of the intermediate data filled in with 0s.

pub fn read_to_end<N: ArrayLength<u8>>(
    &self,
    buf: &mut Vec<u8, N>
) -> Result<usize>

pub fn read(&self, buf: &mut [u8]) -> Result<usize>

pub fn seek(&self, pos: SeekFrom) -> Result<usize>

pub fn write(&self, buf: &[u8]) -> Result<usize>

Trait Implementations

impl<S: Storage> Read for File<'_, '_, S>

fn read(&self, buf: &mut [u8]) -> Result<usize>

Read at most buf.len() bytes. Upon success, return how many bytes were read.

fn read_exact(&self, buf: &mut [u8]) -> Result<()>

impl<S: Storage> Seek for File<'_, '_, S>

fn seek(&self, pos: SeekFrom) -> Result<usize>

Seek to an offset in bytes. If successful, returns the new position from start of file.

impl<S: Storage> Write for File<'_, '_, S>

fn write(&self, buf: &[u8]) -> Result<usize>

Write at most data.len() bytes. The file will not necessarily be updated unless flush is called as there is a cache. Upon success, return how many bytes were written.

fn flush(&self) -> Result<()>

Write out all pending writes to storage.

fn write_all(&self, buf: &[u8]) -> Result<()>