[−][src]Trait futures_io::AsyncWrite
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 data is not yet available, rather than blocking
the calling thread.
Required methods
fn poll_write(
self: Pin<&mut Self>,
cx: &mut Context,
buf: &[u8]
) -> Poll<Result<usize>>
self: Pin<&mut Self>,
cx: &mut Context,
buf: &[u8]
) -> Poll<Result<usize>>
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.
fn poll_flush(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Result<()>>
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.
fn poll_close(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Result<()>>
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>>
self: Pin<&mut Self>,
cx: &mut Context,
bufs: &[IoSlice]
) -> Poll<Result<usize>>
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
buffer in bufs
. 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<T: ?Sized + AsyncWrite + Unpin> AsyncWrite for Box<T>
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fn poll_write(
self: Pin<&mut Self>,
cx: &mut Context,
buf: &[u8]
) -> Poll<Result<usize>>
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self: Pin<&mut Self>,
cx: &mut Context,
buf: &[u8]
) -> Poll<Result<usize>>
fn poll_write_vectored(
self: Pin<&mut Self>,
cx: &mut Context,
bufs: &[IoSlice]
) -> Poll<Result<usize>>
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self: Pin<&mut Self>,
cx: &mut Context,
bufs: &[IoSlice]
) -> Poll<Result<usize>>
fn poll_flush(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Result<()>>
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fn poll_close(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Result<()>>
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impl<'_, T: ?Sized + AsyncWrite + Unpin> AsyncWrite for &'_ mut T
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fn poll_write(
self: Pin<&mut Self>,
cx: &mut Context,
buf: &[u8]
) -> Poll<Result<usize>>
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self: Pin<&mut Self>,
cx: &mut Context,
buf: &[u8]
) -> Poll<Result<usize>>
fn poll_write_vectored(
self: Pin<&mut Self>,
cx: &mut Context,
bufs: &[IoSlice]
) -> Poll<Result<usize>>
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self: Pin<&mut Self>,
cx: &mut Context,
bufs: &[IoSlice]
) -> Poll<Result<usize>>
fn poll_flush(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Result<()>>
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fn poll_close(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Result<()>>
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impl<P> AsyncWrite for Pin<P> where
P: DerefMut + Unpin,
P::Target: AsyncWrite,
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P: DerefMut + Unpin,
P::Target: AsyncWrite,
fn poll_write(
self: Pin<&mut Self>,
cx: &mut Context,
buf: &[u8]
) -> Poll<Result<usize>>
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self: Pin<&mut Self>,
cx: &mut Context,
buf: &[u8]
) -> Poll<Result<usize>>
fn poll_write_vectored(
self: Pin<&mut Self>,
cx: &mut Context,
bufs: &[IoSlice]
) -> Poll<Result<usize>>
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self: Pin<&mut Self>,
cx: &mut Context,
bufs: &[IoSlice]
) -> Poll<Result<usize>>
fn poll_flush(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Result<()>>
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fn poll_close(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Result<()>>
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impl<T: AsMut<[u8]> + Unpin> AsyncWrite for Cursor<T>
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fn poll_write(
self: Pin<&mut Self>,
_: &mut Context,
buf: &[u8]
) -> Poll<Result<usize>>
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self: Pin<&mut Self>,
_: &mut Context,
buf: &[u8]
) -> Poll<Result<usize>>
fn poll_write_vectored(
self: Pin<&mut Self>,
_: &mut Context,
bufs: &[IoSlice]
) -> Poll<Result<usize>>
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self: Pin<&mut Self>,
_: &mut Context,
bufs: &[IoSlice]
) -> Poll<Result<usize>>
fn poll_flush(self: Pin<&mut Self>, _: &mut Context) -> Poll<Result<()>>
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fn poll_close(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Result<()>>
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impl AsyncWrite for Vec<u8>
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fn poll_write(
self: Pin<&mut Self>,
_: &mut Context,
buf: &[u8]
) -> Poll<Result<usize>>
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self: Pin<&mut Self>,
_: &mut Context,
buf: &[u8]
) -> Poll<Result<usize>>
fn poll_write_vectored(
self: Pin<&mut Self>,
_: &mut Context,
bufs: &[IoSlice]
) -> Poll<Result<usize>>
[src]
self: Pin<&mut Self>,
_: &mut Context,
bufs: &[IoSlice]
) -> Poll<Result<usize>>