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
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170

//!
//! Cluster formation and distributed actor instantiation
use crate::children_ref::ChildrenRef;
use crate::context::*;
use crate::message::Message;
use crate::Bastion;

use crate::message::Msg;

use artillery_core::cluster::ap::*;
use artillery_core::epidemic::prelude::*;
use std::sync::Arc;

use core::future::Future;
use futures::future;
use tracing::*;

use lever::table::lotable::*;

use uuid::Uuid;

///
/// Cluster message that is sent and delivered among members
#[derive(Debug)]
pub struct ClusterMessage {
    pub(crate) msg: Msg,
    pub(crate) member: Uuid,
}

impl ClusterMessage {
    ///
    /// Create a `ClusterMessage` from a `Msg` and a member
    pub fn new(msg: Msg, member: Uuid) -> Self {
        ClusterMessage { msg, member }
    }

    ///
    /// Extract a `Msg` from a `ClusterMessage`
    pub fn extract(self) -> Msg {
        self.msg
    }
}

///
/// Distributed context that holds currently formed/forming cluster's context.
#[derive(Debug)]
pub struct DistributedContext {
    bctx: BastionContext,
    me: Uuid,
    members: LOTable<Uuid, ArtilleryMember>,
    cluster: Arc<Cluster>,
}

impl DistributedContext {
    ///
    /// Initializes distributed context with underlying actor's local context and cluster handle.
    fn new(bctx: BastionContext, cluster: Arc<Cluster>, me: Uuid) -> Self {
        DistributedContext {
            bctx,
            me,
            members: LOTable::new(),
            cluster,
        }
    }

    ///
    /// Exposes local bastion context to distributed actor
    pub fn local_ctx(&self) -> &BastionContext {
        &self.bctx
    }

    ///
    /// Gets the current member's node id in the cluster
    ///
    /// This shouldn't be confused with content addressing of actors in the application.
    pub fn current(&self) -> Uuid {
        self.me
    }

    ///
    /// Get current members of the cluster.
    ///
    /// This list is continuously updates with cluster state.
    /// If a node is down it won't appear in this list.
    /// If a node is suspected, it will still be in here. When suspected message delivery isn't guaranteed.
    pub fn members(&self) -> Vec<ArtilleryMember> {
        self.members
            .values()
            .filter(|m| m.host_key() != self.me)
            .collect()
    }

    ///
    /// Send a fire and forget style message to a destined cluster member.
    /// Message needs to be stringified or apply the rules of bastion's [Message] trait.
    pub fn tell<M>(&self, to: &Uuid, msg: M) -> Result<(), M>
    where
        M: Message + AsRef<str>,
    {
        debug!("Sending payload");
        self.cluster.send_payload(*to, msg);
        Ok(())
    }

    ///
    /// Channel that aggregates incoming cluster events to this node.
    pub async fn recv(&self) -> Result<ClusterMessage, ()> {
        debug!(
            "DistributedContext({}): Waiting to receive message.",
            self.me
        );
        loop {
            for (members, event) in self.cluster.events.try_iter() {
                warn!(event = format!("{:?}", event).as_str(), "Cluster event");
                if let ArtilleryMemberEvent::Payload(member, msg) = event {
                    return Ok(ClusterMessage::new(Msg::tell(msg), member.host_key()));
                }

                members.iter().for_each(|m| match m.state() {
                    ArtilleryMemberState::Alive => {
                        let _ = self.members.insert(m.host_key(), m.clone());
                    }
                    ArtilleryMemberState::Down => {
                        let _ = self.members.remove(&m.host_key());
                    }
                    _ => {}
                });
            }
        }
    }
}

///
/// Creates distributed cluster actor
pub(crate) fn cluster_actor<I, F>(
    cluster_config: &'static ArtilleryAPClusterConfig,
    action: I,
) -> Result<ChildrenRef, ()>
where
    I: Fn(Arc<DistributedContext>) -> F + Send + Sync + 'static,
    F: Future<Output = Result<(), ()>> + Send + 'static,
{
    let action = Arc::new(action);

    Bastion::spawn(move |ctx: BastionContext| {
        let ap_cluster = Arc::new(ArtilleryAPCluster::new(cluster_config.clone()).unwrap());
        let dctx = Arc::new(DistributedContext::new(
            ctx,
            ap_cluster.cluster(),
            cluster_config.node_id,
        ));
        let action = action.clone();

        let core = async move {
            let _ap_events = ap_cluster.clone();

            // Detach cluster launch
            let cluster_handle = blocking!(ap_cluster.launch().await);

            let events_handle = blocking!(action(dctx).await);

            future::join(events_handle, cluster_handle).await
        };

        async move {
            run!(core);
            Ok(())
        }
    })
}