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#![allow(unused_variables)]
use protocol::{Message, SystemMsg, ActorMsg};
use actor::actor_ref::ActorRef;
use actor::actor_cell::{Context, PersistenceConf};
/// An Actor represents a struct that will be scheduled for execution when it is sent a message.
///
/// Actors expose an API through messaging. The only means to interact with
/// an actor is through the messaging protocol via the actor's reference,
/// an `ActorRef`.
///
/// When `ActorRef.tell` is used to send a message to an actor, the
/// message is placed in the actor's mailbox and the actor is scheduled
/// for execution.
///
/// When the actor is executed the `receive` function is invoked for each
/// message.
pub trait Actor : Send {
type Msg: Message;
/// Invoked when an actor is being started by the system.
///
/// Any initialization inherent to the actor's role should be
/// performed here.
///
/// Panics in `pre_start` do not invoke the
/// supervision strategy and the actor will be terminated.
fn pre_start(&mut self, ctx: &Context<Self::Msg>) {
}
/// Invoked after an actor has started.
///
/// Any post initialization can be performed here, such as writing
/// to a log file, emmitting metrics.
///
/// Panics in `post_start` follow the supervision strategy.
fn post_start(&mut self, ctx: &Context<Self::Msg>) {
}
/// Invoked after an actor has been stopped.
fn post_stop(&mut self) {
}
/// Invoked when an actor receives a message
///
/// It is guaranteed that only one message in the actor's mailbox is processed
/// at any one time, including `receive`, `other_receive` and `system_receive`.
fn receive(&mut self, ctx: &Context<Self::Msg>, msg: Self::Msg, sender: Option<ActorRef<Self::Msg>>);
/// Invoked when an actor receives a Riker predefined message
///
/// It is guaranteed that only one message in the actor's mailbox is processed
/// at any one time, including `receive`, `other_receive` and `system_receive`.
fn other_receive(&mut self, ctx: &Context<Self::Msg>, msg: ActorMsg<Self::Msg>, sender: Option<ActorRef<Self::Msg>>) {
}
/// Invoked when an actor receives a Riker system message
///
/// It is guaranteed that only one message in the actor's mailbox is processed
/// at any one time, including `receive`, `other_receive` and `system_receive`.
fn system_receive(&mut self, ctx: &Context<Self::Msg>, msg: SystemMsg<Self::Msg>, sender: Option<ActorRef<Self::Msg>>) {
}
/// Return a Some(PersistenceConf) to enable actor persistence.
///
/// # Examples
///
/// ```
/// # use riker::actors::*;
/// struct User {
/// id: String,
/// }
///
/// impl Actor for User {
/// type Msg = String;
///
/// fn persistence_conf(&self) -> Option<PersistenceConf> {
/// Some(PersistenceConf {
/// id: self.id.clone(),
/// keyspace: "user".into()
/// })
/// }
///
/// # fn receive(&mut self, ctx: &Context<Self::Msg>, msg: Self::Msg, sender: Option<ActorRef<Self::Msg>>) {}
/// }
/// ```
/// Events persisted using `ctx.persist_event()` will be replayed in order by
/// passing to `apply_event` when an actor is started, or restarted by a supervisor
fn persistence_conf(&self) -> Option<PersistenceConf> {
None
}
/// Invoked after an event is successfully inserted into the event store.
///
/// State changes are safe to make here.
///
/// Since you should only change state (e.g. self.some_val) when you know
/// the event has been successfully stored in the event store, `apply_event`
/// is the only place that this is guaranteed after `ctx.persist_event()`.
///
/// `ctx.persist_event()` stops further processing of the actor's mailbox messages
/// until the event is successfully inserted in to the event store. Thus you are
/// guaranteed that `apply_event` is invoked before the next message is received.
///
/// # Examples
///
/// ```
/// # use riker::actors::*;
///
/// struct Sensor {
/// id: String,
/// last: u32,
/// count: u32,
/// avg: f64,
/// }
///
/// impl Actor for Sensor {
/// type Msg = u32;
///
/// fn persistence_conf(&self) -> Option<PersistenceConf> {
/// Some(PersistenceConf {
/// id: self.id.clone(),
/// keyspace: "sensor_1".into(),
/// })
/// }
///
/// fn receive(&mut self,
/// ctx: &Context<Self::Msg>,
/// msg: Self::Msg,
/// sender: Option<ActorRef<Self::Msg>>) {
/// // Receive a new sensor reading and store it
/// ctx.persist_event(msg);
/// }
///
/// fn apply_event(&mut self, _ctx: &Context<Self::Msg>, evt: Self::Msg) {
/// // Sensor reading has been stored
/// // Local state can be updated
/// self.last = evt;
/// self.count += 1;
/// self.avg = (self.last / self.count).into();
/// }
/// }
/// ```
fn apply_event(&mut self, ctx: &Context<Self::Msg>, evt: Self::Msg) {
}
/// Invoked for each event when the actor is recovering.
///
/// State changes are safe to make here.
///
/// Since you should only change state (e.g. `self.some_val`) when you know
/// the event exists in the event store, `replay_event`
/// is safe to change the state.
///
/// `replay_event` is used instead of `apply_event` when recovering
/// to allow for different bahavior. Typically replaying should only
/// be used to change state for the purpose of recovering the actor's state
/// and not perform additional messaging.
///
/// # Examples
///
/// ```
/// # use riker::actors::*;
/// struct Sensor {
/// id: String,
/// last: u32,
/// count: u32,
/// avg: f64,
/// }
///
/// impl Actor for Sensor {
/// type Msg = u32;
///
/// fn persistence_conf(&self) -> Option<PersistenceConf> {
/// Some(PersistenceConf {
/// id: self.id.clone(),
/// keyspace: "sensor_1".into(),
/// })
/// }
///
/// fn receive(&mut self,
/// ctx: &Context<Self::Msg>,
/// msg: Self::Msg,
/// sender: Option<ActorRef<Self::Msg>>) {
/// // Receive a new sensor reading and store it
/// ctx.persist_event(msg);
/// }
///
/// fn replay_event(&mut self, _ctx: &Context<Self::Msg>, evt: Self::Msg) {
/// // Received a previously stored sensor reading
/// // Update local state
/// self.last = evt;
/// self.count += 1;
/// self.avg = (self.last / self.count).into();
/// }
/// }
/// ```
fn replay_event(&mut self, ctx: &Context<Self::Msg>, evt: Self::Msg) {
}
/// Return a supervisor strategy that will be used when handling failed child actors.
fn supervisor_strategy(&self) -> Strategy {
Strategy::Restart
}
}
impl<A: Actor + ?Sized> Actor for Box<A> {
type Msg = A::Msg;
fn pre_start(&mut self, ctx: &Context<Self::Msg>) {
(**self).pre_start(ctx);
}
fn post_start(&mut self, ctx: &Context<Self::Msg>) {
(**self).post_start(ctx)
}
fn post_stop(&mut self) {
(**self).post_stop()
}
fn receive(&mut self, ctx: &Context<Self::Msg>, msg: Self::Msg, sender: Option<ActorRef<Self::Msg>>) {
(**self).receive(ctx, msg, sender);
}
fn other_receive(&mut self, ctx: &Context<Self::Msg>, msg: ActorMsg<Self::Msg>, sender: Option<ActorRef<Self::Msg>>) {
(**self).other_receive(ctx, msg, sender);
}
fn system_receive(&mut self, ctx: &Context<Self::Msg>, msg: SystemMsg<Self::Msg>, sender: Option<ActorRef<Self::Msg>>) {
(**self).system_receive(ctx, msg, sender)
}
fn persistence_conf(&self) -> Option<PersistenceConf> {
(**self).persistence_conf()
}
fn apply_event(&mut self, ctx: &Context<Self::Msg>, evt: Self::Msg) {
(**self).apply_event(ctx, evt)
}
fn replay_event(&mut self, ctx: &Context<Self::Msg>, evt: Self::Msg) {
(**self).apply_event(ctx, evt)
}
fn supervisor_strategy(&self) -> Strategy {
(**self).supervisor_strategy()
}
}
/// The actor trait object
pub type BoxActor<Msg> = Box<Actor<Msg=Msg> + Send>;
/// Supervision strategy
///
/// Returned in `Actor.supervision_strategy`
pub enum Strategy {
/// Stop the child actor
Stop,
/// Attempt to restart the child actor
Restart,
/// Escalate the failure to a parent
Escalate,
}