Trait polkadot_node_subsystem::gen::futures::SinkExt
source · pub trait SinkExt<Item>: Sink<Item> {
Show 17 methods
// Provided methods
fn with<U, Fut, F, E>(self, f: F) -> With<Self, Item, U, Fut, F>
where F: FnMut(U) -> Fut,
Fut: Future<Output = Result<Item, E>>,
E: From<Self::Error>,
Self: Sized { ... }
fn with_flat_map<U, St, F>(self, f: F) -> WithFlatMap<Self, Item, U, St, F>
where F: FnMut(U) -> St,
St: Stream<Item = Result<Item, Self::Error>>,
Self: Sized { ... }
fn sink_map_err<E, F>(self, f: F) -> SinkMapErr<Self, F>
where F: FnOnce(Self::Error) -> E,
Self: Sized { ... }
fn sink_err_into<E>(self) -> SinkErrInto<Self, Item, E>
where Self: Sized,
Self::Error: Into<E> { ... }
fn buffer(self, capacity: usize) -> Buffer<Self, Item>
where Self: Sized { ... }
fn close(&mut self) -> Close<'_, Self, Item> ⓘ
where Self: Unpin { ... }
fn fanout<Si>(self, other: Si) -> Fanout<Self, Si>
where Self: Sized,
Item: Clone,
Si: Sink<Item, Error = Self::Error> { ... }
fn flush(&mut self) -> Flush<'_, Self, Item> ⓘ
where Self: Unpin { ... }
fn send(&mut self, item: Item) -> Send<'_, Self, Item> ⓘ
where Self: Unpin { ... }
fn feed(&mut self, item: Item) -> Feed<'_, Self, Item> ⓘ
where Self: Unpin { ... }
fn send_all<St, 'a>(
&'a mut self,
stream: &'a mut St
) -> SendAll<'a, Self, St> ⓘ
where St: TryStream<Ok = Item, Error = Self::Error> + Stream + Unpin + ?Sized,
Self: Unpin { ... }
fn left_sink<Si2>(self) -> Either<Self, Si2> ⓘ
where Si2: Sink<Item, Error = Self::Error>,
Self: Sized { ... }
fn right_sink<Si1>(self) -> Either<Si1, Self> ⓘ
where Si1: Sink<Item, Error = Self::Error>,
Self: Sized { ... }
fn poll_ready_unpin(
&mut self,
cx: &mut Context<'_>
) -> Poll<Result<(), Self::Error>>
where Self: Unpin { ... }
fn start_send_unpin(&mut self, item: Item) -> Result<(), Self::Error>
where Self: Unpin { ... }
fn poll_flush_unpin(
&mut self,
cx: &mut Context<'_>
) -> Poll<Result<(), Self::Error>>
where Self: Unpin { ... }
fn poll_close_unpin(
&mut self,
cx: &mut Context<'_>
) -> Poll<Result<(), Self::Error>>
where Self: Unpin { ... }
}
Expand description
An extension trait for Sink
s that provides a variety of convenient
combinator functions.
Provided Methods§
sourcefn with<U, Fut, F, E>(self, f: F) -> With<Self, Item, U, Fut, F>where
F: FnMut(U) -> Fut,
Fut: Future<Output = Result<Item, E>>,
E: From<Self::Error>,
Self: Sized,
fn with<U, Fut, F, E>(self, f: F) -> With<Self, Item, U, Fut, F>where F: FnMut(U) -> Fut, Fut: Future<Output = Result<Item, E>>, E: From<Self::Error>, Self: Sized,
Composes a function in front of the sink.
This adapter produces a new sink that passes each value through the
given function f
before sending it to self
.
To process each value, f
produces a future, which is then polled to
completion before passing its result down to the underlying sink. If the
future produces an error, that error is returned by the new sink.
Note that this function consumes the given sink, returning a wrapped
version, much like Iterator::map
.
sourcefn with_flat_map<U, St, F>(self, f: F) -> WithFlatMap<Self, Item, U, St, F>where
F: FnMut(U) -> St,
St: Stream<Item = Result<Item, Self::Error>>,
Self: Sized,
fn with_flat_map<U, St, F>(self, f: F) -> WithFlatMap<Self, Item, U, St, F>where F: FnMut(U) -> St, St: Stream<Item = Result<Item, Self::Error>>, Self: Sized,
Composes a function in front of the sink.
This adapter produces a new sink that passes each value through the
given function f
before sending it to self
.
To process each value, f
produces a stream, of which each value
is passed to the underlying sink. A new value will not be accepted until
the stream has been drained
Note that this function consumes the given sink, returning a wrapped
version, much like Iterator::flat_map
.
Examples
use futures::channel::mpsc;
use futures::sink::SinkExt;
use futures::stream::{self, StreamExt};
let (tx, rx) = mpsc::channel(5);
let mut tx = tx.with_flat_map(|x| {
stream::iter(vec![Ok(42); x])
});
tx.send(5).await.unwrap();
drop(tx);
let received: Vec<i32> = rx.collect().await;
assert_eq!(received, vec![42, 42, 42, 42, 42]);
sourcefn sink_map_err<E, F>(self, f: F) -> SinkMapErr<Self, F>where
F: FnOnce(Self::Error) -> E,
Self: Sized,
fn sink_map_err<E, F>(self, f: F) -> SinkMapErr<Self, F>where F: FnOnce(Self::Error) -> E, Self: Sized,
Transforms the error returned by the sink.
sourcefn sink_err_into<E>(self) -> SinkErrInto<Self, Item, E>where
Self: Sized,
Self::Error: Into<E>,
fn sink_err_into<E>(self) -> SinkErrInto<Self, Item, E>where Self: Sized, Self::Error: Into<E>,
Map this sink’s error to a different error type using the Into
trait.
If wanting to map errors of a Sink + Stream
, use .sink_err_into().err_into()
.
sourcefn buffer(self, capacity: usize) -> Buffer<Self, Item>where
Self: Sized,
fn buffer(self, capacity: usize) -> Buffer<Self, Item>where Self: Sized,
Adds a fixed-size buffer to the current sink.
The resulting sink will buffer up to capacity
items when the
underlying sink is unwilling to accept additional items. Calling flush
on the buffered sink will attempt to both empty the buffer and complete
processing on the underlying sink.
Note that this function consumes the given sink, returning a wrapped
version, much like Iterator::map
.
This method is only available when the std
or alloc
feature of this
library is activated, and it is activated by default.
sourcefn fanout<Si>(self, other: Si) -> Fanout<Self, Si>where
Self: Sized,
Item: Clone,
Si: Sink<Item, Error = Self::Error>,
fn fanout<Si>(self, other: Si) -> Fanout<Self, Si>where Self: Sized, Item: Clone, Si: Sink<Item, Error = Self::Error>,
Fanout items to multiple sinks.
This adapter clones each incoming item and forwards it to both this as well as the other sink at the same time.
sourcefn flush(&mut self) -> Flush<'_, Self, Item> ⓘwhere
Self: Unpin,
fn flush(&mut self) -> Flush<'_, Self, Item> ⓘwhere Self: Unpin,
Flush the sink, processing all pending items.
This adapter is intended to be used when you want to stop sending to the sink until all current requests are processed.
sourcefn send(&mut self, item: Item) -> Send<'_, Self, Item> ⓘwhere
Self: Unpin,
fn send(&mut self, item: Item) -> Send<'_, Self, Item> ⓘwhere Self: Unpin,
A future that completes after the given item has been fully processed into the sink, including flushing.
Note that, because of the flushing requirement, it is usually better
to batch together items to send via feed
or send_all
,
rather than flushing between each item.
sourcefn feed(&mut self, item: Item) -> Feed<'_, Self, Item> ⓘwhere
Self: Unpin,
fn feed(&mut self, item: Item) -> Feed<'_, Self, Item> ⓘwhere Self: Unpin,
A future that completes after the given item has been received by the sink.
Unlike send
, the returned future does not flush the sink.
It is the caller’s responsibility to ensure all pending items
are processed, which can be done via flush
or close
.
sourcefn send_all<St, 'a>(&'a mut self, stream: &'a mut St) -> SendAll<'a, Self, St> ⓘwhere
St: TryStream<Ok = Item, Error = Self::Error> + Stream + Unpin + ?Sized,
Self: Unpin,
fn send_all<St, 'a>(&'a mut self, stream: &'a mut St) -> SendAll<'a, Self, St> ⓘwhere St: TryStream<Ok = Item, Error = Self::Error> + Stream + Unpin + ?Sized, Self: Unpin,
A future that completes after the given stream has been fully processed into the sink, including flushing.
This future will drive the stream to keep producing items until it is exhausted, sending each item to the sink. It will complete once both the stream is exhausted, the sink has received all items, and the sink has been flushed. Note that the sink is not closed. If the stream produces an error, that error will be returned by this future without flushing the sink.
Doing sink.send_all(stream)
is roughly equivalent to
stream.forward(sink)
. The returned future will exhaust all items from
stream
and send them to self
.
sourcefn left_sink<Si2>(self) -> Either<Self, Si2> ⓘwhere
Si2: Sink<Item, Error = Self::Error>,
Self: Sized,
fn left_sink<Si2>(self) -> Either<Self, Si2> ⓘwhere Si2: Sink<Item, Error = Self::Error>, Self: Sized,
Wrap this sink in an Either
sink, making it the left-hand variant
of that Either
.
This can be used in combination with the right_sink
method to write if
statements that evaluate to different streams in different branches.
sourcefn right_sink<Si1>(self) -> Either<Si1, Self> ⓘwhere
Si1: Sink<Item, Error = Self::Error>,
Self: Sized,
fn right_sink<Si1>(self) -> Either<Si1, Self> ⓘwhere Si1: Sink<Item, Error = Self::Error>, Self: Sized,
Wrap this stream in an Either
stream, making it the right-hand variant
of that Either
.
This can be used in combination with the left_sink
method to write if
statements that evaluate to different streams in different branches.
sourcefn poll_ready_unpin(
&mut self,
cx: &mut Context<'_>
) -> Poll<Result<(), Self::Error>>where
Self: Unpin,
fn poll_ready_unpin( &mut self, cx: &mut Context<'_> ) -> Poll<Result<(), Self::Error>>where Self: Unpin,
A convenience method for calling Sink::poll_ready
on Unpin
sink types.
sourcefn start_send_unpin(&mut self, item: Item) -> Result<(), Self::Error>where
Self: Unpin,
fn start_send_unpin(&mut self, item: Item) -> Result<(), Self::Error>where Self: Unpin,
A convenience method for calling Sink::start_send
on Unpin
sink types.
sourcefn poll_flush_unpin(
&mut self,
cx: &mut Context<'_>
) -> Poll<Result<(), Self::Error>>where
Self: Unpin,
fn poll_flush_unpin( &mut self, cx: &mut Context<'_> ) -> Poll<Result<(), Self::Error>>where Self: Unpin,
A convenience method for calling Sink::poll_flush
on Unpin
sink types.
sourcefn poll_close_unpin(
&mut self,
cx: &mut Context<'_>
) -> Poll<Result<(), Self::Error>>where
Self: Unpin,
fn poll_close_unpin( &mut self, cx: &mut Context<'_> ) -> Poll<Result<(), Self::Error>>where Self: Unpin,
A convenience method for calling Sink::poll_close
on Unpin
sink types.