liminal-rs 0.15.0

A conversation-based messaging bus built on beamr
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
60
61

use std::sync::{Arc, mpsc};

use crate::channel::ChannelMode;
use crate::conversation::participant::ConsumptionPermit;
use crate::conversation::{
    ConversationActor, ConversationSupervisor, CrashPolicy, EchoBehaviour, ParticipantBehaviour,
    ParticipantPid,
};
use crate::envelope::Envelope;
use crate::error::LiminalError;

#[derive(Debug)]
struct NoReply;

impl ParticipantBehaviour for NoReply {
    fn process(&self, _: &Envelope) -> Option<Envelope> {
        None
    }
}

pub struct ControlledConsumer {
    pub(crate) owner: ConversationActor,
    pub(crate) pid: ParticipantPid,
    pub(crate) permit: ConsumptionPermit,
    pub(crate) parked: mpsc::Receiver<()>,
}

impl ControlledConsumer {
    pub(crate) fn new(supervisor: &ConversationSupervisor) -> Result<Self, LiminalError> {
        Self::with_behaviour(supervisor, Arc::new(NoReply))
    }

    pub(crate) fn echo(supervisor: &ConversationSupervisor) -> Result<Self, LiminalError> {
        Self::with_behaviour(supervisor, Arc::new(EchoBehaviour))
    }

    fn with_behaviour(
        supervisor: &ConversationSupervisor,
        behaviour: Arc<dyn ParticipantBehaviour>,
    ) -> Result<Self, LiminalError> {
        let (owner, pid) = supervisor.spawn_with_participant(
            behaviour,
            None,
            ChannelMode::Ephemeral,
            CrashPolicy::RouteToNext,
        )?;
        let (permit, parked) = supervisor.hold_participant_consumption(pid)?;
        Ok(Self {
            owner,
            pid,
            permit,
            parked,
        })
    }
}

impl Drop for ControlledConsumer {
    fn drop(&mut self) {
        self.owner.finalize();
    }
}