actix 0.7.3

Actor framework for Rust
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59

use futures::{Async, Poll};
use std::mem;

use actor::Actor;
use fut::ActorFuture;

#[derive(Debug)]
pub enum Chain<A, B, C>
where
    A: ActorFuture,
{
    First(A, C),
    Second(B),
    Done,
}

impl<A, B, C> Chain<A, B, C>
where
    A: ActorFuture,
    B: ActorFuture<Actor = A::Actor>,
{
    pub fn new(a: A, c: C) -> Chain<A, B, C> {
        Chain::First(a, c)
    }

    pub fn poll<F>(
        &mut self, srv: &mut A::Actor, ctx: &mut <A::Actor as Actor>::Context, f: F,
    ) -> Poll<B::Item, B::Error>
    where
        F: FnOnce(
            Result<A::Item, A::Error>,
            C,
            &mut A::Actor,
            &mut <A::Actor as Actor>::Context,
        ) -> Result<Result<B::Item, B>, B::Error>,
    {
        let a_result = match *self {
            Chain::First(ref mut a, _) => match a.poll(srv, ctx) {
                Ok(Async::NotReady) => return Ok(Async::NotReady),
                Ok(Async::Ready(t)) => Ok(t),
                Err(e) => Err(e),
            },
            Chain::Second(ref mut b) => return b.poll(srv, ctx),
            Chain::Done => panic!("cannot poll a chained future twice"),
        };
        let data = match mem::replace(self, Chain::Done) {
            Chain::First(_, c) => c,
            _ => panic!(),
        };
        match f(a_result, data, srv, ctx)? {
            Ok(e) => Ok(Async::Ready(e)),
            Err(mut b) => {
                let ret = b.poll(srv, ctx);
                *self = Chain::Second(b);
                ret
            }
        }
    }
}