Split devtools implementation into sensible modules.

This commit is contained in:
Josh Matthews 2014-09-01 10:08:10 -04:00
parent cdb4037ca2
commit bb9955c281
7 changed files with 699 additions and 555 deletions

View file

@ -0,0 +1,120 @@
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/// General actor system infrastructure.
use std::any::{Any, AnyRefExt, AnyMutRefExt};
use std::collections::hashmap::HashMap;
use std::io::TcpStream;
use std::mem::{transmute, transmute_copy};
use std::raw::TraitObject;
use serialize::json;
/// A common trait for all devtools actors that encompasses an immutable name
/// and the ability to process messages that are directed to particular actors.
/// TODO: ensure the name is immutable
pub trait Actor: Any {
fn handle_message(&self,
registry: &ActorRegistry,
msg_type: &String,
msg: &json::Object,
stream: &mut TcpStream) -> bool;
fn name(&self) -> String;
}
impl<'a> AnyMutRefExt<'a> for &'a mut Actor {
fn downcast_mut<T: 'static>(self) -> Option<&'a mut T> {
if self.is::<T>() {
unsafe {
// Get the raw representation of the trait object
let to: TraitObject = transmute_copy(&self);
// Extract the data pointer
Some(transmute(to.data))
}
} else {
None
}
}
}
impl<'a> AnyRefExt<'a> for &'a Actor {
fn is<T: 'static>(self) -> bool {
//FIXME: This implementation is bogus since get_type_id is private now.
// However, this implementation is only needed so long as there's a Rust bug
// that prevents downcast_ref from giving realistic return values, and this is
// ok since we're careful with the types we pull out of the hashmap.
/*let t = TypeId::of::<T>();
let boxed = self.get_type_id();
t == boxed*/
true
}
fn downcast_ref<T: 'static>(self) -> Option<&'a T> {
if self.is::<T>() {
unsafe {
// Get the raw representation of the trait object
let to: TraitObject = transmute_copy(&self);
// Extract the data pointer
Some(transmute(to.data))
}
} else {
None
}
}
}
/// A list of known, owned actors.
pub struct ActorRegistry {
actors: HashMap<String, Box<Actor+Send+Sized>>,
}
impl ActorRegistry {
/// Create an empty registry.
pub fn new() -> ActorRegistry {
ActorRegistry {
actors: HashMap::new(),
}
}
/// Add an actor to the registry of known actors that can receive messages.
pub fn register(&mut self, actor: Box<Actor+Send+Sized>) {
self.actors.insert(actor.name().to_string(), actor);
}
/// Find an actor by registered name
pub fn find<'a, T: 'static>(&'a self, name: &str) -> &'a T {
//FIXME: Rust bug forces us to implement bogus Any for Actor since downcast_ref currently
// fails for unknown reasons.
/*let actor: &Actor+Send+Sized = *self.actors.find(&name.to_string()).unwrap();
(actor as &Any).downcast_ref::<T>().unwrap()*/
self.actors.find(&name.to_string()).unwrap().as_ref::<T>().unwrap()
}
/// Find an actor by registered name
pub fn find_mut<'a, T: 'static>(&'a mut self, name: &str) -> &'a mut T {
//FIXME: Rust bug forces us to implement bogus Any for Actor since downcast_ref currently
// fails for unknown reasons.
/*let actor: &mut Actor+Send+Sized = *self.actors.find_mut(&name.to_string()).unwrap();
(actor as &mut Any).downcast_mut::<T>().unwrap()*/
self.actors.find_mut(&name.to_string()).unwrap().downcast_mut::<T>().unwrap()
}
/// Attempt to process a message as directed by its `to` property. If the actor is not
/// found or does not indicate that it knew how to process the message, ignore the failure.
pub fn handle_message(&self, msg: &json::Object, stream: &mut TcpStream) {
let to = msg.find(&"to".to_string()).unwrap().as_string().unwrap();
match self.actors.find(&to.to_string()) {
None => println!("message received for unknown actor \"{:s}\"", to),
Some(actor) => {
let msg_type = msg.find(&"type".to_string()).unwrap().as_string().unwrap();
if !actor.handle_message(self, &msg_type.to_string(), msg, stream) {
println!("unexpected message type \"{:s}\" found for actor \"{:s}\"",
msg_type, to);
}
}
}
}
}