Trait futures_util::io::AsyncRead [−][src]
Read bytes asynchronously.
This trait is analogous to the std::io::Read
trait, but integrates
with the asynchronous task system. In particular, the poll_read
method, unlike Read::read
, will automatically queue the current task
for wakeup and return if data is not yet available, rather than blocking
the calling thread.
Required methods
pub fn poll_read(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
Attempt to read from the AsyncRead
into buf
.
On success, returns Poll::Ready(Ok(num_bytes_read))
.
If no data is available for reading, 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
readable 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.
Provided methods
pub fn poll_read_vectored(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>
Attempt to read from the AsyncRead
into bufs
using vectored
IO operations.
This method is similar to poll_read
, but allows data to be read
into multiple buffers using a single operation.
On success, returns Poll::Ready(Ok(num_bytes_read))
.
If no data is available for reading, 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
readable or is closed.
By default, this method delegates to using poll_read
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<'_> AsyncRead for &'_ [u8]
[src]
pub fn poll_read(
self: Pin<&mut &'_ [u8]>,
&mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut &'_ [u8]>,
&mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
pub fn poll_read_vectored(
self: Pin<&mut &'_ [u8]>,
&mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut &'_ [u8]>,
&mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>
impl<T> AsyncRead for Box<T, Global> where
T: AsyncRead + Unpin + ?Sized,
[src]
T: AsyncRead + Unpin + ?Sized,
pub fn poll_read(
self: Pin<&mut Box<T, Global>>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut Box<T, Global>>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
pub fn poll_read_vectored(
self: Pin<&mut Box<T, Global>>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut Box<T, Global>>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>
impl<P> AsyncRead for Pin<P> where
P: DerefMut + Unpin,
<P as Deref>::Target: AsyncRead,
[src]
P: DerefMut + Unpin,
<P as Deref>::Target: AsyncRead,
pub fn poll_read(
self: Pin<&mut Pin<P>>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut Pin<P>>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
pub fn poll_read_vectored(
self: Pin<&mut Pin<P>>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut Pin<P>>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>
impl<'_, T> AsyncRead for &'_ mut T where
T: AsyncRead + Unpin + ?Sized,
[src]
T: AsyncRead + Unpin + ?Sized,
pub fn poll_read(
self: Pin<&mut &'_ mut T>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut &'_ mut T>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
pub fn poll_read_vectored(
self: Pin<&mut &'_ mut T>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut &'_ mut T>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>
Implementors
impl AsyncRead for Empty
[src]
impl AsyncRead for Repeat
[src]
fn poll_read(
self: Pin<&mut Self>,
_: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize>>
[src]
self: Pin<&mut Self>,
_: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize>>
fn poll_read_vectored(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize>>
[src]
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize>>
impl<A, B> AsyncRead for Either<A, B> where
A: AsyncRead,
B: AsyncRead,
[src]
A: AsyncRead,
B: AsyncRead,
fn poll_read(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize>>
[src]
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize>>
fn poll_read_vectored(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize>>
[src]
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize>>
impl<R: AsyncRead> AsyncRead for BufReader<R>
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fn poll_read(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize>>
[src]
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize>>
fn poll_read_vectored(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize>>
[src]
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize>>
impl<R: AsyncRead> AsyncRead for ReadHalf<R>
[src]
fn poll_read(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize>>
[src]
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize>>
fn poll_read_vectored(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize>>
[src]
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize>>
impl<R: AsyncRead> AsyncRead for Take<R>
[src]
fn poll_read(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
impl<St> AsyncRead for IntoAsyncRead<St> where
St: TryStream<Error = Error> + Unpin,
St::Ok: AsRef<[u8]>,
[src]
St: TryStream<Error = Error> + Unpin,
St::Ok: AsRef<[u8]>,
fn poll_read(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize>>
[src]
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize>>
impl<T> AsyncRead for AllowStdIo<T> where
T: Read,
[src]
T: Read,
fn poll_read(
self: Pin<&mut Self>,
_: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize>>
[src]
self: Pin<&mut Self>,
_: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize>>
fn poll_read_vectored(
self: Pin<&mut Self>,
_: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize>>
[src]
self: Pin<&mut Self>,
_: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize>>
impl<T, U> AsyncRead for Chain<T, U> where
T: AsyncRead,
U: AsyncRead,
[src]
T: AsyncRead,
U: AsyncRead,
fn poll_read(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize>>
[src]
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize>>
fn poll_read_vectored(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize>>
[src]
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize>>
impl<T: AsRef<[u8]> + Unpin> AsyncRead for Cursor<T>
[src]
fn poll_read(
self: Pin<&mut Self>,
_cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize>>
[src]
self: Pin<&mut Self>,
_cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize>>
fn poll_read_vectored(
self: Pin<&mut Self>,
_: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize>>
[src]
self: Pin<&mut Self>,
_: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize>>