Trait futures::io::AsyncWrite

pub trait AsyncWrite {
    pub fn poll_write(
        self: Pin<&mut Self>, 
        cx: &mut Context<'_>, 
        buf: &[u8]
    ) -> Poll<Result<usize, Error>>;
    pub fn poll_flush(
        self: Pin<&mut Self>, 
        cx: &mut Context<'_>
    ) -> Poll<Result<(), Error>>;
    pub fn poll_close(
        self: Pin<&mut Self>, 
        cx: &mut Context<'_>
    ) -> Poll<Result<(), Error>>;

    pub fn poll_write_vectored(
        self: Pin<&mut Self>, 
        cx: &mut Context<'_>, 
        bufs: &[IoSlice<'_>]
    ) -> Poll<Result<usize, Error>> { ... }
}

[−] Expand description

Write bytes asynchronously.

This trait is analogous to the std::io::Write trait, but integrates with the asynchronous task system. In particular, the poll_write method, unlike Write::write, will automatically queue the current task for wakeup and return if the writer cannot take more data, rather than blocking the calling thread.

Required methods

pub fn poll_write(
    self: Pin<&mut Self>,
    cx: &mut Context<'_>,
    buf: &[u8]
) -> Poll<Result<usize, Error>>[−]

Attempt to write bytes from buf into the object.

On success, returns Poll::Ready(Ok(num_bytes_written)).

If the object is not ready for writing, the method returns Poll::Pending and arranges for the current task (via cx.waker().wake_by_ref()) to receive a notification when the object becomes writable or is closed.

Implementation

This function may not return errors of kind WouldBlock or Interrupted. Implementations must convert WouldBlock into Poll::Pending and either internally retry or convert Interrupted into another error kind.

poll_write must try to make progress by flushing the underlying object if that is the only way the underlying object can become writable again.

pub fn poll_flush(
    self: Pin<&mut Self>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>[−]

Attempt to flush the object, ensuring that any buffered data reach their destination.

On success, returns Poll::Ready(Ok(())).

If flushing cannot immediately complete, this method returns Poll::Pending and arranges for the current task (via cx.waker().wake_by_ref()) to receive a notification when the object can make progress towards flushing.

Implementation

This function may not return errors of kind WouldBlock or Interrupted. Implementations must convert WouldBlock into Poll::Pending and either internally retry or convert Interrupted into another error kind.

It only makes sense to do anything here if you actually buffer data.

pub fn poll_close(
    self: Pin<&mut Self>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>[−]

Attempt to close the object.

On success, returns Poll::Ready(Ok(())).

If closing cannot immediately complete, this function returns Poll::Pending and arranges for the current task (via cx.waker().wake_by_ref()) to receive a notification when the object can make progress towards closing.

Implementation

This function may not return errors of kind WouldBlock or Interrupted. Implementations must convert WouldBlock into Poll::Pending and either internally retry or convert Interrupted into another error kind.

Provided methods

pub fn poll_write_vectored(
    self: Pin<&mut Self>,
    cx: &mut Context<'_>,
    bufs: &[IoSlice<'_>]
) -> Poll<Result<usize, Error>>[−]

Attempt to write bytes from bufs into the object using vectored IO operations.

This method is similar to poll_write, but allows data from multiple buffers to be written using a single operation.

On success, returns Poll::Ready(Ok(num_bytes_written)).

If the object is not ready for writing, the method returns Poll::Pending and arranges for the current task (via cx.waker().wake_by_ref()) to receive a notification when the object becomes writable or is closed.

By default, this method delegates to using poll_write on the first nonempty buffer in bufs, or an empty one if none exists. Objects which support vectored IO should override this method.

Implementation

This function may not return errors of kind WouldBlock or Interrupted. Implementations must convert WouldBlock into Poll::Pending and either internally retry or convert Interrupted into another error kind.

Implementations on Foreign Types

impl<P> AsyncWrite for Pin<P> where
    P: DerefMut + Unpin,
    <P as Deref>::Target: AsyncWrite, 

[+] Show hidden undocumented items

pub fn poll_write(
    self: Pin<&mut Pin<P>>,
    cx: &mut Context<'_>,
    buf: &[u8]
) -> Poll<Result<usize, Error>>

pub fn poll_write_vectored(
    self: Pin<&mut Pin<P>>,
    cx: &mut Context<'_>,
    bufs: &[IoSlice<'_>]
) -> Poll<Result<usize, Error>>

pub fn poll_flush(
    self: Pin<&mut Pin<P>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

pub fn poll_close(
    self: Pin<&mut Pin<P>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

impl<'_, T> AsyncWrite for &'_ mut T where
    T: AsyncWrite + Unpin + ?Sized, 

[+] Show hidden undocumented items

pub fn poll_write(
    self: Pin<&mut &'_ mut T>,
    cx: &mut Context<'_>,
    buf: &[u8]
) -> Poll<Result<usize, Error>>

pub fn poll_write_vectored(
    self: Pin<&mut &'_ mut T>,
    cx: &mut Context<'_>,
    bufs: &[IoSlice<'_>]
) -> Poll<Result<usize, Error>>

pub fn poll_flush(
    self: Pin<&mut &'_ mut T>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

pub fn poll_close(
    self: Pin<&mut &'_ mut T>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

impl AsyncWrite for Vec<u8, Global>

[+] Show hidden undocumented items

pub fn poll_write(
    self: Pin<&mut Vec<u8, Global>>,
    &mut Context<'_>,
    buf: &[u8]
) -> Poll<Result<usize, Error>>

pub fn poll_write_vectored(
    self: Pin<&mut Vec<u8, Global>>,
    &mut Context<'_>,
    bufs: &[IoSlice<'_>]
) -> Poll<Result<usize, Error>>

pub fn poll_flush(
    self: Pin<&mut Vec<u8, Global>>,
    &mut Context<'_>
) -> Poll<Result<(), Error>>

pub fn poll_close(
    self: Pin<&mut Vec<u8, Global>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

impl<T> AsyncWrite for Box<T, Global> where
    T: AsyncWrite + Unpin + ?Sized, 

[+] Show hidden undocumented items

pub fn poll_write(
    self: Pin<&mut Box<T, Global>>,
    cx: &mut Context<'_>,
    buf: &[u8]
) -> Poll<Result<usize, Error>>

pub fn poll_write_vectored(
    self: Pin<&mut Box<T, Global>>,
    cx: &mut Context<'_>,
    bufs: &[IoSlice<'_>]
) -> Poll<Result<usize, Error>>

pub fn poll_flush(
    self: Pin<&mut Box<T, Global>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

pub fn poll_close(
    self: Pin<&mut Box<T, Global>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

Implementors

impl AsyncWrite for Cursor<Box<[u8], Global>>

[+] Show hidden undocumented items

pub fn poll_write(
    self: Pin<&mut Cursor<Box<[u8], Global>>>,
    &mut Context<'_>,
    buf: &[u8]
) -> Poll<Result<usize, Error>>

pub fn poll_write_vectored(
    self: Pin<&mut Cursor<Box<[u8], Global>>>,
    &mut Context<'_>,
    bufs: &[IoSlice<'_>]
) -> Poll<Result<usize, Error>>

pub fn poll_flush(
    self: Pin<&mut Cursor<Box<[u8], Global>>>,
    &mut Context<'_>
) -> Poll<Result<(), Error>>

pub fn poll_close(
    self: Pin<&mut Cursor<Box<[u8], Global>>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

impl AsyncWrite for Cursor<Vec<u8, Global>>

[+] Show hidden undocumented items

pub fn poll_write(
    self: Pin<&mut Cursor<Vec<u8, Global>>>,
    &mut Context<'_>,
    buf: &[u8]
) -> Poll<Result<usize, Error>>

pub fn poll_write_vectored(
    self: Pin<&mut Cursor<Vec<u8, Global>>>,
    &mut Context<'_>,
    bufs: &[IoSlice<'_>]
) -> Poll<Result<usize, Error>>

pub fn poll_flush(
    self: Pin<&mut Cursor<Vec<u8, Global>>>,
    &mut Context<'_>
) -> Poll<Result<(), Error>>

pub fn poll_close(
    self: Pin<&mut Cursor<Vec<u8, Global>>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

impl AsyncWrite for Sink

[+] Show hidden undocumented items

pub fn poll_write(
    self: Pin<&mut Sink>,
    &mut Context<'_>,
    buf: &[u8]
) -> Poll<Result<usize, Error>>

pub fn poll_write_vectored(
    self: Pin<&mut Sink>,
    &mut Context<'_>,
    bufs: &[IoSlice<'_>]
) -> Poll<Result<usize, Error>>

pub fn poll_flush(
    self: Pin<&mut Sink>,
    &mut Context<'_>
) -> Poll<Result<(), Error>>

pub fn poll_close(
    self: Pin<&mut Sink>,
    &mut Context<'_>
) -> Poll<Result<(), Error>>

impl<'_> AsyncWrite for Cursor<&'_ mut Vec<u8, Global>>

[+] Show hidden undocumented items

pub fn poll_write(
    self: Pin<&mut Cursor<&'_ mut Vec<u8, Global>>>,
    &mut Context<'_>,
    buf: &[u8]
) -> Poll<Result<usize, Error>>

pub fn poll_write_vectored(
    self: Pin<&mut Cursor<&'_ mut Vec<u8, Global>>>,
    &mut Context<'_>,
    bufs: &[IoSlice<'_>]
) -> Poll<Result<usize, Error>>

pub fn poll_flush(
    self: Pin<&mut Cursor<&'_ mut Vec<u8, Global>>>,
    &mut Context<'_>
) -> Poll<Result<(), Error>>

pub fn poll_close(
    self: Pin<&mut Cursor<&'_ mut Vec<u8, Global>>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

impl<'_> AsyncWrite for Cursor<&'_ mut [u8]>

[+] Show hidden undocumented items

pub fn poll_write(
    self: Pin<&mut Cursor<&'_ mut [u8]>>,
    &mut Context<'_>,
    buf: &[u8]
) -> Poll<Result<usize, Error>>

pub fn poll_write_vectored(
    self: Pin<&mut Cursor<&'_ mut [u8]>>,
    &mut Context<'_>,
    bufs: &[IoSlice<'_>]
) -> Poll<Result<usize, Error>>

pub fn poll_flush(
    self: Pin<&mut Cursor<&'_ mut [u8]>>,
    &mut Context<'_>
) -> Poll<Result<(), Error>>

pub fn poll_close(
    self: Pin<&mut Cursor<&'_ mut [u8]>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

impl<A, B> AsyncWrite for Either<A, B> where
    B: AsyncWrite,
    A: AsyncWrite, 

[+] Show hidden undocumented items

pub fn poll_write(
    self: Pin<&mut Either<A, B>>,
    cx: &mut Context<'_>,
    buf: &[u8]
) -> Poll<Result<usize, Error>>

pub fn poll_write_vectored(
    self: Pin<&mut Either<A, B>>,
    cx: &mut Context<'_>,
    bufs: &[IoSlice<'_>]
) -> Poll<Result<usize, Error>>

pub fn poll_flush(
    self: Pin<&mut Either<A, B>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

pub fn poll_close(
    self: Pin<&mut Either<A, B>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

impl<R> AsyncWrite for BufReader<R> where
    R: AsyncWrite, 

[+] Show hidden undocumented items

pub fn poll_write(
    self: Pin<&mut BufReader<R>>,
    cx: &mut Context<'_>,
    buf: &[u8]
) -> Poll<Result<usize, Error>>

pub fn poll_write_vectored(
    self: Pin<&mut BufReader<R>>,
    cx: &mut Context<'_>,
    bufs: &[IoSlice<'_>]
) -> Poll<Result<usize, Error>>

pub fn poll_flush(
    self: Pin<&mut BufReader<R>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

pub fn poll_close(
    self: Pin<&mut BufReader<R>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

impl<St> AsyncWrite for IntoAsyncRead<St> where
    St: TryStream<Error = Error> + AsyncWrite + Unpin,
    <St as TryStream>::Ok: AsRef<[u8]>, 

[+] Show hidden undocumented items

pub fn poll_write(
    self: Pin<&mut IntoAsyncRead<St>>,
    cx: &mut Context<'_>,
    buf: &[u8]
) -> Poll<Result<usize, Error>>

pub fn poll_flush(
    self: Pin<&mut IntoAsyncRead<St>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

pub fn poll_close(
    self: Pin<&mut IntoAsyncRead<St>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

impl<T> AsyncWrite for AllowStdIo<T> where
    T: Write, 

[+] Show hidden undocumented items

pub fn poll_write(
    self: Pin<&mut AllowStdIo<T>>,
    &mut Context<'_>,
    buf: &[u8]
) -> Poll<Result<usize, Error>>

pub fn poll_write_vectored(
    self: Pin<&mut AllowStdIo<T>>,
    &mut Context<'_>,
    bufs: &[IoSlice<'_>]
) -> Poll<Result<usize, Error>>

pub fn poll_flush(
    self: Pin<&mut AllowStdIo<T>>,
    &mut Context<'_>
) -> Poll<Result<(), Error>>

pub fn poll_close(
    self: Pin<&mut AllowStdIo<T>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

impl<W> AsyncWrite for BufWriter<W> where
    W: AsyncWrite, 

[+] Show hidden undocumented items

pub fn poll_write(
    self: Pin<&mut BufWriter<W>>,
    cx: &mut Context<'_>,
    buf: &[u8]
) -> Poll<Result<usize, Error>>

pub fn poll_write_vectored(
    self: Pin<&mut BufWriter<W>>,
    cx: &mut Context<'_>,
    bufs: &[IoSlice<'_>]
) -> Poll<Result<usize, Error>>

pub fn poll_flush(
    self: Pin<&mut BufWriter<W>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

pub fn poll_close(
    self: Pin<&mut BufWriter<W>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

impl<W> AsyncWrite for WriteHalf<W> where
    W: AsyncWrite, 

[+] Show hidden undocumented items

pub fn poll_write(
    self: Pin<&mut WriteHalf<W>>,
    cx: &mut Context<'_>,
    buf: &[u8]
) -> Poll<Result<usize, Error>>

pub fn poll_write_vectored(
    self: Pin<&mut WriteHalf<W>>,
    cx: &mut Context<'_>,
    bufs: &[IoSlice<'_>]
) -> Poll<Result<usize, Error>>

pub fn poll_flush(
    self: Pin<&mut WriteHalf<W>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

pub fn poll_close(
    self: Pin<&mut WriteHalf<W>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

impl<T: Write> AsyncWrite for Async<T>

impl<T> AsyncWrite for &Async<T> where     &'a T: Write,

impl AsyncWrite for ChildStdin

impl<T: Write + Send + 'static> AsyncWrite for Unblock<T>

impl<T: Write> AsyncWrite for AssertAsync<T>

impl<W: AsyncWrite> AsyncWrite for BufWriter<W>

impl AsyncWrite for Cursor<&mut [u8]>

impl AsyncWrite for Cursor<&mut Vec<u8>>

impl AsyncWrite for Cursor<Vec<u8>>

impl AsyncWrite for Sink

impl<T: AsyncWrite + Unpin> AsyncWrite for WriteHalf<T>

impl<IO> AsyncWrite for TlsStream<IO> where     IO: AsyncRead + AsyncWrite + Unpin,

impl<IO> AsyncWrite for TlsStream<IO> where     IO: AsyncRead + AsyncWrite + Unpin,

impl<T> AsyncWrite for TlsStream<T> where     T: AsyncRead + AsyncWrite + Unpin,

impl<TInner: AsyncWrite> AsyncWrite for BandwidthConnecLogging<TInner>

impl<A, B> AsyncWrite for EitherOutput<A, B> where     A: AsyncWrite,     B: AsyncWrite,

impl<P> AsyncWrite for SubstreamRef<P> where     P: Deref,     P::Target: StreamMuxer,

impl AsyncWrite for DummyStream

impl<S> AsyncWrite for DeflateOutput<S> where     S: AsyncWrite + Unpin,

impl<T: AsyncWrite + Unpin> AsyncWrite for NoiseOutput<T>

impl<S: AsyncRead + AsyncWrite + Unpin> AsyncWrite for PlainTextOutput<S>

impl<S: AsyncRead + AsyncWrite> AsyncWrite for PnetOutput<S>

impl AsyncWrite for Connection

impl<TInner> AsyncWrite for Negotiated<TInner> where     TInner: AsyncWrite + AsyncRead + Unpin,

impl<S> AsyncWrite for RwStreamSink<S> where     S: TryStream + Sink<<S as TryStream>::Ok, Error = Error>,     <S as TryStream>::Ok: for<'r> From<&'r [u8]>,

impl AsyncWrite for Stream