Trait AsyncWrite
pub trait AsyncWrite {
// Required methods
fn poll_write(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &[u8],
) -> Poll<Result<usize, Error>>;
fn poll_flush(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
) -> Poll<Result<(), Error>>;
fn poll_close(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
) -> Poll<Result<(), Error>>;
// Provided method
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§
fn poll_write(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &[u8],
) -> Poll<Result<usize, Error>>
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.
fn poll_flush(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
) -> Poll<Result<(), Error>>
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.
fn poll_close(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
) -> Poll<Result<(), Error>>
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§
fn poll_write_vectored(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &[IoSlice<'_>],
) -> Poll<Result<usize, Error>>
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 AsyncWrite for Vec<u8>
impl AsyncWrite for Vec<u8>
fn poll_write( self: Pin<&mut Vec<u8>>, _: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_write_vectored( self: Pin<&mut Vec<u8>>, _: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut Vec<u8>>, _: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut Vec<u8>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl AsyncWrite for ChildStdin
impl AsyncWrite for ChildStdin
§impl AsyncWrite for Cursor<&mut Vec<u8>>
impl AsyncWrite for Cursor<&mut Vec<u8>>
fn poll_write( self: Pin<&mut Cursor<&mut Vec<u8>>>, _: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_close( self: Pin<&mut Cursor<&mut Vec<u8>>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_flush( self: Pin<&mut Cursor<&mut Vec<u8>>>, _: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl AsyncWrite for Cursor<&mut Vec<u8>>
impl AsyncWrite for Cursor<&mut Vec<u8>>
fn poll_write( self: Pin<&mut Cursor<&mut Vec<u8>>>, _: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_write_vectored( self: Pin<&mut Cursor<&mut Vec<u8>>>, _: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut Cursor<&mut Vec<u8>>>, _: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut Cursor<&mut Vec<u8>>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl AsyncWrite for Cursor<&mut [u8]>
impl AsyncWrite for Cursor<&mut [u8]>
fn poll_write( self: Pin<&mut Cursor<&mut [u8]>>, _: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_write_vectored( self: Pin<&mut Cursor<&mut [u8]>>, _: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut Cursor<&mut [u8]>>, _: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut Cursor<&mut [u8]>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl AsyncWrite for Cursor<&mut [u8]>
impl AsyncWrite for Cursor<&mut [u8]>
fn poll_write( self: Pin<&mut Cursor<&mut [u8]>>, _: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_write_vectored( self: Pin<&mut Cursor<&mut [u8]>>, _: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut Cursor<&mut [u8]>>, _: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut Cursor<&mut [u8]>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl AsyncWrite for Cursor<Box<[u8]>>
impl AsyncWrite for Cursor<Box<[u8]>>
fn poll_write( self: Pin<&mut Cursor<Box<[u8]>>>, _: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_write_vectored( self: Pin<&mut Cursor<Box<[u8]>>>, _: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut Cursor<Box<[u8]>>>, _: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut Cursor<Box<[u8]>>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl AsyncWrite for Cursor<Vec<u8>>
impl AsyncWrite for Cursor<Vec<u8>>
fn poll_write( self: Pin<&mut Cursor<Vec<u8>>>, _: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_close( self: Pin<&mut Cursor<Vec<u8>>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_flush( self: Pin<&mut Cursor<Vec<u8>>>, _: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl AsyncWrite for Cursor<Vec<u8>>
impl AsyncWrite for Cursor<Vec<u8>>
fn poll_write( self: Pin<&mut Cursor<Vec<u8>>>, _: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_write_vectored( self: Pin<&mut Cursor<Vec<u8>>>, _: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut Cursor<Vec<u8>>>, _: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut Cursor<Vec<u8>>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl AsyncWrite for PipeWriter
impl AsyncWrite for PipeWriter
§impl AsyncWrite for Sink
impl AsyncWrite for Sink
§impl AsyncWrite for Sink
impl AsyncWrite for Sink
§impl AsyncWrite for Sink
impl AsyncWrite for Sink
fn poll_write( self: Pin<&mut Sink>, _: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_write_vectored( self: Pin<&mut Sink>, _: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut Sink>, _: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut Sink>, _: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl AsyncWrite for TcpStream
impl AsyncWrite for TcpStream
fn poll_write( self: Pin<&mut TcpStream>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut TcpStream>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut TcpStream>, _: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_write_vectored( self: Pin<&mut TcpStream>, cx: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>
§impl AsyncWrite for UnixStream
impl AsyncWrite for UnixStream
§impl AsyncWrite for Writer
impl AsyncWrite for Writer
§impl<A, B> AsyncWrite for Either<A, B>where
A: AsyncWrite,
B: AsyncWrite,
impl<A, B> AsyncWrite for Either<A, B>where
A: AsyncWrite,
B: AsyncWrite,
fn poll_write( self: Pin<&mut Either<A, B>>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_write_vectored( self: Pin<&mut Either<A, B>>, cx: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut Either<A, B>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut Either<A, B>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl<P> AsyncWrite for Pin<P>
impl<P> AsyncWrite for Pin<P>
fn poll_write( self: Pin<&mut Pin<P>>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_write_vectored( self: Pin<&mut Pin<P>>, cx: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut Pin<P>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut Pin<P>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl<R> AsyncWrite for BufReader<R>where
R: AsyncWrite,
impl<R> AsyncWrite for BufReader<R>where
R: AsyncWrite,
fn poll_write( self: Pin<&mut BufReader<R>>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut BufReader<R>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut BufReader<R>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl<R> AsyncWrite for BufReader<R>where
R: AsyncWrite,
impl<R> AsyncWrite for BufReader<R>where
R: AsyncWrite,
fn poll_write( self: Pin<&mut BufReader<R>>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_write_vectored( self: Pin<&mut BufReader<R>>, cx: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut BufReader<R>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut BufReader<R>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl<St> AsyncWrite for IntoAsyncRead<St>
impl<St> AsyncWrite for IntoAsyncRead<St>
fn poll_write( self: Pin<&mut IntoAsyncRead<St>>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut IntoAsyncRead<St>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut IntoAsyncRead<St>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl<T> AsyncWrite for &Async<T>
impl<T> AsyncWrite for &Async<T>
fn poll_write( self: Pin<&mut &Async<T>>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_write_vectored( self: Pin<&mut &Async<T>>, cx: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut &Async<T>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut &Async<T>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl<T> AsyncWrite for &mut T
impl<T> AsyncWrite for &mut T
fn poll_write( self: Pin<&mut &mut T>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_write_vectored( self: Pin<&mut &mut T>, cx: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut &mut T>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut &mut T>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl<T> AsyncWrite for Box<T>
impl<T> AsyncWrite for Box<T>
fn poll_write( self: Pin<&mut Box<T>>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_write_vectored( self: Pin<&mut Box<T>>, cx: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut Box<T>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut Box<T>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl<T> AsyncWrite for AllowStdIo<T>where
T: Write,
impl<T> AsyncWrite for AllowStdIo<T>where
T: Write,
fn poll_write( self: Pin<&mut AllowStdIo<T>>, _: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_write_vectored( self: Pin<&mut AllowStdIo<T>>, _: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut AllowStdIo<T>>, _: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut AllowStdIo<T>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl<T> AsyncWrite for AssertAsync<T>where
T: Write,
impl<T> AsyncWrite for AssertAsync<T>where
T: Write,
fn poll_write( self: Pin<&mut AssertAsync<T>>, _: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_write_vectored( self: Pin<&mut AssertAsync<T>>, _: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut AssertAsync<T>>, _: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut AssertAsync<T>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl<T> AsyncWrite for AssertAsync<T>where
T: Write,
impl<T> AsyncWrite for AssertAsync<T>where
T: Write,
fn poll_write( self: Pin<&mut AssertAsync<T>>, _: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_write_vectored( self: Pin<&mut AssertAsync<T>>, _: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut AssertAsync<T>>, _: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut AssertAsync<T>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl<T> AsyncWrite for Async<T>where
T: IoSafe + Write,
impl<T> AsyncWrite for Async<T>where
T: IoSafe + Write,
fn poll_write( self: Pin<&mut Async<T>>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_write_vectored( self: Pin<&mut Async<T>>, cx: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut Async<T>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut Async<T>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl<T> AsyncWrite for Unblock<T>
impl<T> AsyncWrite for Unblock<T>
§impl<T> AsyncWrite for WriteHalf<T>where
T: AsyncWrite + Unpin,
impl<T> AsyncWrite for WriteHalf<T>where
T: AsyncWrite + Unpin,
fn poll_write( self: Pin<&mut WriteHalf<T>>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut WriteHalf<T>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut WriteHalf<T>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl<W> AsyncWrite for BufWriter<W>where
W: AsyncWrite,
impl<W> AsyncWrite for BufWriter<W>where
W: AsyncWrite,
fn poll_write( self: Pin<&mut BufWriter<W>>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut BufWriter<W>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut BufWriter<W>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl<W> AsyncWrite for BufWriter<W>where
W: AsyncWrite,
impl<W> AsyncWrite for BufWriter<W>where
W: AsyncWrite,
fn poll_write( self: Pin<&mut BufWriter<W>>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize, Error>>
fn poll_write_vectored( self: Pin<&mut BufWriter<W>>, cx: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>
fn poll_flush( self: Pin<&mut BufWriter<W>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut BufWriter<W>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
§impl<W> AsyncWrite for LineWriter<W>where
W: AsyncWrite,
impl<W> AsyncWrite for LineWriter<W>where
W: AsyncWrite,
§fn poll_flush(
self: Pin<&mut LineWriter<W>>,
cx: &mut Context<'_>,
) -> Poll<Result<(), Error>>
fn poll_flush( self: Pin<&mut LineWriter<W>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
Forward to buf_writer
’s BufWriter::poll_flush()
§fn poll_close(
self: Pin<&mut LineWriter<W>>,
cx: &mut Context<'_>,
) -> Poll<Result<(), Error>>
fn poll_close( self: Pin<&mut LineWriter<W>>, cx: &mut Context<'_>, ) -> Poll<Result<(), Error>>
Forward to buf_writer
’s BufWriter::poll_close()