Struct File 

pub struct File(/* private fields */);

an open file (closed when dropped): an OS file, or a stream of a vfs mount

Implementations

impl File

pub fn open(path: &str, mode: u32) -> Option<File>

FO_READ (existing, read only), FO_WRITE (create / truncate), FO_RW (open or create); on every mount (vfs.rs)

pub fn create_new(path: &str) -> Option<File>

Create a named file exclusively; never open an existing path (a mount without OS files: exclusive inside this process).

pub fn open_temp(dir: Option<&str>) -> Option<File>

a new file without a lasting name in dir (None = temp_dir) that disappears when it is closed (also after a crash); a mount without OS files: a file in memory [plat_file_open_temp]

pub fn read_at(&self, off: u64, buf: &mut [u8]) -> Option<usize>

bytes read at off (fewer at the end of the file), None on an error before any byte

pub fn write_at(&self, off: u64, buf: &[u8]) -> Option<usize>

bytes written at off (the file grows as needed), None on an error before any byte

pub fn size(&self) -> Option<u64>

pub fn sync(&self) -> bool

write cached data to the disk (a mount: where its readers find it)

pub fn set_len(&self, len: u64) -> bool

cut or extend the file to len bytes

Trait Implementations

impl Stream for File

fn read_at(&self, off: u64, buf: &mut [u8]) -> Option<usize>

bytes read at off (fewer at the end), None on an error

fn write_at(&self, off: u64, buf: &[u8]) -> Option<usize>

bytes written at off (the file grows); None for a read-only stream

fn size(&self) -> Option<u64>

fn set_len(&self, len: u64) -> bool

cut or extend to len bytes

fn sync(&self) -> bool

the data is where readers of the mount find it