Trait futures::io::AsyncRead [−][src]
pub trait AsyncRead { fn poll_read(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>; unsafe fn initializer(&self) -> Initializer { ... } fn poll_read_vectored(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>> { ... } }
Expand description
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
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>>
Expand description
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
unsafe fn initializer(&self) -> Initializer
[src]
Expand description
Determines if this AsyncRead
er can work with buffers of
uninitialized memory.
The default implementation returns an initializer which will zero buffers.
This method is only available when the read-initializer
feature of this
library is activated.
Safety
This method is unsafe
because an AsyncRead
er could otherwise
return a non-zeroing Initializer
from another AsyncRead
type
without an unsafe
block.
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>>
Expand description
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<P> AsyncRead for Pin<P> where
P: DerefMut + Unpin,
<P as Deref>::Target: AsyncRead,
[src]
impl<P> AsyncRead for Pin<P> where
P: DerefMut + Unpin,
<P as Deref>::Target: AsyncRead,
[src]pub unsafe fn initializer(&self) -> Initializer
[src]
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 Box<T, Global> where
T: AsyncRead + Unpin + ?Sized,
[src]
impl<T> AsyncRead for Box<T, Global> where
T: AsyncRead + Unpin + ?Sized,
[src]pub unsafe fn initializer(&self) -> Initializer
[src]
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<'_, T> AsyncRead for &'_ mut T where
T: AsyncRead + Unpin + ?Sized,
[src]
impl<'_, T> AsyncRead for &'_ mut T where
T: AsyncRead + Unpin + ?Sized,
[src]pub unsafe fn initializer(&self) -> Initializer
[src]
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<A, B> AsyncRead for Either<A, B> where
B: AsyncRead,
A: AsyncRead,
[src]
impl<A, B> AsyncRead for Either<A, B> where
B: AsyncRead,
A: AsyncRead,
[src]pub unsafe fn initializer(&self) -> Initializer
[src]
pub fn poll_read(
self: Pin<&mut Either<A, B>>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut Either<A, B>>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
pub fn poll_read_vectored(
self: Pin<&mut Either<A, B>>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut Either<A, B>>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>
impl<R> AsyncRead for Compat01As03<R> where
R: AsyncRead,
[src]
impl<R> AsyncRead for Compat01As03<R> where
R: AsyncRead,
[src]pub unsafe fn initializer(&self) -> Initializer
[src]
pub fn poll_read(
self: Pin<&mut Compat01As03<R>>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut Compat01As03<R>>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
impl<R> AsyncRead for BufReader<R> where
R: AsyncRead,
[src]
impl<R> AsyncRead for BufReader<R> where
R: AsyncRead,
[src]pub fn poll_read(
self: Pin<&mut BufReader<R>>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut BufReader<R>>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
pub fn poll_read_vectored(
self: Pin<&mut BufReader<R>>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut BufReader<R>>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>
pub unsafe fn initializer(&self) -> Initializer
[src]
impl<St> AsyncRead for IntoAsyncRead<St> where
St: TryStream<Error = Error> + Unpin,
<St as TryStream>::Ok: AsRef<[u8]>,
[src]
impl<St> AsyncRead for IntoAsyncRead<St> where
St: TryStream<Error = Error> + Unpin,
<St as TryStream>::Ok: AsRef<[u8]>,
[src]impl<T> AsyncRead for AllowStdIo<T> where
T: Read,
[src]
impl<T> AsyncRead for AllowStdIo<T> where
T: Read,
[src]pub fn poll_read(
self: Pin<&mut AllowStdIo<T>>,
&mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut AllowStdIo<T>>,
&mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
pub fn poll_read_vectored(
self: Pin<&mut AllowStdIo<T>>,
&mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut AllowStdIo<T>>,
&mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>
pub unsafe fn initializer(&self) -> Initializer
[src]
impl<T, U> AsyncRead for Chain<T, U> where
T: AsyncRead,
U: AsyncRead,
[src]
impl<T, U> AsyncRead for Chain<T, U> where
T: AsyncRead,
U: AsyncRead,
[src]pub fn poll_read(
self: Pin<&mut Chain<T, U>>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut Chain<T, U>>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
pub fn poll_read_vectored(
self: Pin<&mut Chain<T, U>>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut Chain<T, U>>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>
pub unsafe fn initializer(&self) -> Initializer
[src]
impl<W> AsyncRead for BufWriter<W> where
W: AsyncRead,
[src]
impl<W> AsyncRead for BufWriter<W> where
W: AsyncRead,
[src]pub unsafe fn initializer(&self) -> Initializer
[src]
pub fn poll_read(
self: Pin<&mut BufWriter<W>>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut BufWriter<W>>,
cx: &mut Context<'_>,
buf: &mut [u8]
) -> Poll<Result<usize, Error>>
pub fn poll_read_vectored(
self: Pin<&mut BufWriter<W>>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>
[src]
self: Pin<&mut BufWriter<W>>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>