Struct tokio_file_unix::File

pub struct File<F>(pub F);

Used to wrap file-like objects so they can be used with tokio_core::reactor::PollEvented.

Normally, you should use File::new_nb rather than the File constructor directly, unless the underlying file descriptor has already been set to nonblocking mode. Using a file that is not in nonblocking mode for asynchronous I/O will lead to subtle bugs.

impl Evented for File<std::fs::File>;
impl Evented for File<StdFile<StdinLock>>;
impl Evented for File<impl AsRawFd>;

Example: wrapping standard input

let stdin = std::io::stdin();
let file = File::new_nb(StdFile(stdin.lock()))?;

Methods

impl<F: AsRawFd> File<F>

fn new_nb(file: F) -> Result<Self>

Wraps a file-like object so it can be used with tokio_core::reactor::PollEvented, and also enables nonblocking mode on the underlying file descriptor.

fn new_nb(std::fs::File) -> Result<impl Evented + Read + Write>;
fn new_nb(StdFile<StdinLock>) -> Result<impl Evented + Read + Write>;
fn new_nb(impl AsRawFd) -> Result<impl Evented>;

fn set_nonblocking(&mut self, nonblocking: bool) -> Result<()>

Sets the nonblocking mode of the underlying file descriptor to either on (true) or off (false). If File::new_nb was previously used to construct the File, then nonblocking mode has already been turned on.

Implementation detail: uses fcntl to set O_NONBLOCK.

fn into_io(self, handle: &Handle) -> Result<PollEvented<Self>>

Converts into a pollable object that supports std::io::AsyncRead and std::io::AsyncWrite, making it suitable for tokio_io::io::*.

If the underlying file descriptor refers to a regular file, this may fail with “Operation not permitted” (EPERM).

fn into_io(File<std::fs::File>, &Handle) -> Result<impl AsyncRead + AsyncWrite>;
fn into_io(File<StdFile<StdinLock>>, &Handle) -> Result<impl AsyncRead + AsyncWrite>;
fn into_io(File<impl AsRawFd + Read>, &Handle) -> Result<impl AsyncRead>;
fn into_io(File<impl AsRawFd + Write>, &Handle) -> Result<impl AsyncWrite>;
fn into_io(File<impl AsRawFd + Read + Write>, &Handle) -> Result<impl AsyncRead + AsyncWrite>;

impl<F: AsRawFd + Read> File<F>

fn into_reader(self, handle: &Handle) -> Result<BufReader<PollEvented<Self>>>

Converts into a pollable object that supports std::io::Read and std::io::ReadBuf, making it suitable for tokio_io::io::read_*.

If the underlying file descriptor refers to a regular file, this may fail with “Operation not permitted” (EPERM).

fn into_reader(File<std::fs::File>, &Handle) -> Result<impl ReadBuf>;
fn into_reader(File<StdFile<StdinLock>>, &Handle) -> Result<impl ReadBuf>;
fn into_reader(File<impl AsRawFd + Read>, &Handle) -> Result<impl ReadBuf>;

Trait Implementations

impl<F: Debug> Debug for File<F>

fn fmt(&self, __arg_0: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<F: AsRawFd> AsRawFd for File<F>

fn as_raw_fd(&self) -> RawFd

Extracts the raw file descriptor.

impl<F: AsRawFd> Evented for File<F>

fn register(
    &self,
    poll: &Poll,
    token: Token,
    interest: Ready,
    opts: PollOpt
) -> Result<()>

Register self with the given Poll instance.

fn reregister(
    &self,
    poll: &Poll,
    token: Token,
    interest: Ready,
    opts: PollOpt
) -> Result<()>

Re-register self with the given Poll instance.

fn deregister(&self, poll: &Poll) -> Result<()>

Deregister self from the given Poll instance

impl<F: Read> Read for File<F>

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

Pull some bytes from this source into the specified buffer, returning how many bytes were read.

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

Read all bytes until EOF in this source, placing them into buf.

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Read all bytes until EOF in this source, placing them into buf.

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

Read the exact number of bytes required to fill buf.

fn by_ref(&mut self) -> &mut Self

Creates a "by reference" adaptor for this instance of Read.

fn bytes(self) -> Bytes<Self>

Transforms this Read instance to an Iterator over its bytes.

fn chars(self) -> Chars<Self>

🔬 This is a nightly-only experimental API. (io)

the semantics of a partial read/write of where errors happen is currently unclear and may change

Transforms this Read instance to an Iterator over chars.

fn chain<R>(self, next: R) -> Chain<Self, R> where
    R: Read, 

Creates an adaptor which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>

Creates an adaptor which will read at most limit bytes from it.

impl<F: Write> Write for File<F>

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

Write a buffer into this object, returning how many bytes were written.

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

Flush this output stream, ensuring that all intermediately buffered contents reach their destination.

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

Attempts to write an entire buffer into this write.

fn write_fmt(&mut self, fmt: Arguments) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

fn by_ref(&mut self) -> &mut Self

Creates a "by reference" adaptor for this instance of Write.