Trait actix::fut::ActorFuture

pub trait ActorFuture {
    type Output;
    type Actor: Actor;
    pub fn poll(
        self: Pin<&mut Self>, 
        srv: &mut Self::Actor, 
        ctx: &mut <Self::Actor as Actor>::Context, 
        task: &mut Context<'_>
    ) -> Poll<Self::Output>;

    pub fn map<F, U>(self, f: F) -> Map<Self, F>
    where
        F: FnOnce(Self::Output, &mut Self::Actor, &mut <Self::Actor as Actor>::Context) -> U,
        Self: Sized,
    { ... }
    pub fn then<F, B>(self, f: F) -> Then<Self, B, F>
    where
        F: FnOnce(Self::Output, &mut Self::Actor, &mut <Self::Actor as Actor>::Context) -> B,
        B: IntoActorFuture<Actor = Self::Actor>,
        Self: Sized,
    { ... }
    pub fn timeout(self, timeout: Duration) -> Timeout<Self>
    where
        Self: Sized,
    { ... }
}

Trait for types which are a placeholder of a value that may become available at some later point in time.

ActorFuture is very similar to a regular Future, only with subsequent combinator closures accepting the actor and its context, in addition to the result.

ActorFuture allows for use cases where future processing requires access to the actor or its context.

Here is an example of a handler on a single actor, deferring work to another actor, and then updating the initiating actor's state:

use actix::prelude::*;

// The response type returned by the actor future
type OriginalActorResponse = ();
// The error type returned by the actor future
type MessageError = ();
// This is the needed result for the DeferredWork message
// It's a result that combine both Response and Error from the future response.
type DeferredWorkResult = Result<OriginalActorResponse, MessageError>;

impl Handler<DeferredWork> for OriginalActor {
    // Notice the `Response` is an `ActorFuture`-ized version of `Self::Message::Result`.
    type Result = ResponseActFuture<Self, Result<OriginalActorResponse, MessageError>>;

    fn handle(&mut self, _msg: DeferredWork, _ctx: &mut Context<Self>) -> Self::Result {
        // this creates a `Future` representing the `.send` and subsequent `Result` from
        // `other_actor`
        let send_to_other = self.other_actor
            .send(OtherMessage {});

        // Wrap that `Future` so subsequent chained handlers can access
        // the `actor` (`self` in the  synchronous code) as well as the context.
        let send_to_other = actix::fut::wrap_future::<_, Self>(send_to_other);

        // once the wrapped future resolves, update this actor's state
        let update_self = send_to_other.map(|result, actor, _ctx| {
            // Actor's state updated here
            match result {
                Ok(v) => {
                    actor.inner_state.update_from(v);
                    Ok(())
                },
                // Failed to send message to other_actor
                Err(_e) => Err(()),
            }
        });

        // return the wrapped future
        Box::pin(update_self)
    }
}

See also into_actor, which provides future conversion using trait

Associated Types

type Output

The type of value that this future will resolved with if it is successful.

type Actor: Actor

The actor within which this future runs

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Required methods

pub fn poll(
    self: Pin<&mut Self>,
    srv: &mut Self::Actor,
    ctx: &mut <Self::Actor as Actor>::Context,
    task: &mut Context<'_>
) -> Poll<Self::Output>

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Provided methods

pub fn map<F, U>(self, f: F) -> Map<Self, F> where
    F: FnOnce(Self::Output, &mut Self::Actor, &mut <Self::Actor as Actor>::Context) -> U,
    Self: Sized, 

Map this future's result to a different type, returning a new future of the resulting type.

pub fn then<F, B>(self, f: F) -> Then<Self, B, F> where
    F: FnOnce(Self::Output, &mut Self::Actor, &mut <Self::Actor as Actor>::Context) -> B,
    B: IntoActorFuture<Actor = Self::Actor>,
    Self: Sized, 

Chain on a computation for when a future finished, passing the result of the future to the provided closure f.

pub fn timeout(self, timeout: Duration) -> Timeout<Self> where
    Self: Sized, 

Add timeout to futures chain.

err value get returned as a timeout error.

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Implementations on Foreign Types

impl<F: ActorFuture + Unpin + ?Sized> ActorFuture for Box<F>

type Output = F::Output

type Actor = F::Actor

pub fn poll(
    self: Pin<&mut Self>,
    srv: &mut Self::Actor,
    ctx: &mut <Self::Actor as Actor>::Context,
    task: &mut Context<'_>
) -> Poll<Self::Output>

impl<P> ActorFuture for Pin<P> where
    P: Unpin + DerefMut,
    <P as Deref>::Target: ActorFuture, 

type Output = <<P as Deref>::Target as ActorFuture>::Output

type Actor = <<P as Deref>::Target as ActorFuture>::Actor

pub fn poll(
    self: Pin<&mut Self>,
    srv: &mut Self::Actor,
    ctx: &mut <Self::Actor as Actor>::Context,
    task: &mut Context<'_>
) -> Poll<Self::Output>

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Implementors

impl ActorFuture for TcpConnector

type Output = Result<TcpStream, ResolverError>

type Actor = Resolver

pub fn poll(
    self: Pin<&mut Self>,
    _: &mut Resolver,
    _: &mut Context<Resolver>,
    cx: &mut Context<'_>
) -> Poll<Self::Output>

impl<A> ActorFuture for TimerFunc<A> where
    A: Actor, 

type Output = ()

type Actor = A

pub fn poll(
    self: Pin<&mut Self>,
    act: &mut Self::Actor,
    ctx: &mut <Self::Actor as Actor>::Context,
    task: &mut Context<'_>
) -> Poll<Self::Output>

impl<A, B> ActorFuture for Either<A, B> where
    A: ActorFuture,
    B: ActorFuture<Output = A::Output, Actor = A::Actor>, 

type Output = A::Output

type Actor = A::Actor

pub fn poll(
    self: Pin<&mut Self>,
    act: &mut A::Actor,
    ctx: &mut <A::Actor as Actor>::Context,
    task: &mut Context<'_>
) -> Poll<A::Output>

impl<A, B, F> ActorFuture for Then<A, B, F> where
    A: ActorFuture,
    B: IntoActorFuture<Actor = A::Actor>,
    F: FnOnce(A::Output, &mut A::Actor, &mut <A::Actor as Actor>::Context) -> B, 

type Output = B::Output

type Actor = A::Actor

pub fn poll(
    self: Pin<&mut Self>,
    act: &mut A::Actor,
    ctx: &mut <A::Actor as Actor>::Context,
    task: &mut Context<'_>
) -> Poll<B::Output>

impl<F> ActorFuture for Timeout<F> where
    F: ActorFuture, 

type Output = Result<F::Output, ()>

type Actor = F::Actor

pub fn poll(
    self: Pin<&mut Self>,
    act: &mut F::Actor,
    ctx: &mut <F::Actor as Actor>::Context,
    task: &mut Context<'_>
) -> Poll<Self::Output>

impl<F, A> ActorFuture for FutureWrap<F, A> where
    F: Future,
    A: Actor, 

type Output = F::Output

type Actor = A

pub fn poll(
    self: Pin<&mut Self>,
    _: &mut Self::Actor,
    _: &mut <Self::Actor as Actor>::Context,
    task: &mut Context<'_>
) -> Poll<Self::Output>

impl<S, F, Fut, T> ActorFuture for StreamFold<S, F, Fut, T> where
    S: ActorStream,
    F: FnMut(T, S::Item, &mut S::Actor, &mut <S::Actor as Actor>::Context) -> Fut,
    Fut: IntoActorFuture<Output = T, Actor = S::Actor>,
    Fut::Future: ActorFuture, 

type Output = T

type Actor = S::Actor

pub fn poll(
    self: Pin<&mut Self>,
    act: &mut S::Actor,
    ctx: &mut <S::Actor as Actor>::Context,
    task: &mut Context<'_>
) -> Poll<T>

impl<S: ActorStream> ActorFuture for StreamFinish<S>

type Output = ()

type Actor = S::Actor

pub fn poll(
    self: Pin<&mut Self>,
    act: &mut S::Actor,
    ctx: &mut <S::Actor as Actor>::Context,
    task: &mut Context<'_>
) -> Poll<()>

impl<T, A> ActorFuture for Ready<T, A> where
    A: Actor, 

type Output = T

type Actor = A

pub fn poll(
    self: Pin<&mut Self>,
    _: &mut Self::Actor,
    _: &mut <Self::Actor as Actor>::Context,
    _: &mut Context<'_>
) -> Poll<Self::Output>

impl<T, E, A> ActorFuture for FutureResult<T, E, A> where
    A: Actor, 

type Output = Result<T, E>

type Actor = A

pub fn poll(
    self: Pin<&mut Self>,
    _: &mut Self::Actor,
    _: &mut <Self::Actor as Actor>::Context,
    _: &mut Context<'_>
) -> Poll<Self::Output>

impl<U, A, F> ActorFuture for Map<A, F> where
    A: ActorFuture,
    F: FnOnce(A::Output, &mut A::Actor, &mut <A::Actor as Actor>::Context) -> U, 

type Output = U

type Actor = A::Actor

pub fn poll(
    self: Pin<&mut Self>,
    act: &mut Self::Actor,
    ctx: &mut <A::Actor as Actor>::Context,
    task: &mut Context<'_>
) -> Poll<Self::Output>

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