rearchitect event transmission so that the parents/children of each module are explicitly specified and we establish the linkages between them

Cargo.toml

@@ -14,6 +14,7 @@ env_logger = "0.5.3"
 transformable_channels = "0.1.1"
 time = "0.1"
 regex = "0.2"
+multimap = "0.4.0"
 pvn = { git = "http://gitlab.monarch-pass.net/malacoda/pvn.git" }
 echobox = { git = "http://gitlab.monarch-pass.net/malacoda/echobox.git" }
 stc = { git = "http://gitlab.monarch-pass.net/malacoda/stc.git" }

src/event/mod.rs

@@ -1,8 +1,5 @@
 use {Message, Channel, User};
 
-use std::sync::Arc;
-use std::collections::btree_set::BTreeSet;
-
 #[derive(Debug)]
 pub enum Event {
     Message { message: Message },     // A user sends a message
@@ -18,15 +15,13 @@ pub enum Event {
 pub struct Envelope {
     pub from: Option<String>,
     pub event: Event,
-    pub to: Vec<String>
 }
 
 impl Envelope {
     pub fn new (event: Event) -> Envelope {
         Envelope {
             from: None,
-            event: event,
+            event: event
-            to: vec![]
         }
     }
 }

src/lib.rs

@@ -7,6 +7,7 @@ extern crate echobox;
 extern crate transformable_channels;
 extern crate stc;
 extern crate regex;
+extern crate multimap;
 
 #[macro_use]
 extern crate hlua;
@@ -27,6 +28,7 @@ use std::sync::mpsc;
 use std::sync::mpsc::Sender;
 
 use transformable_channels::mpsc::TransformableSender;
+use multimap::MultiMap;
 
 mod helpers;
 
@@ -34,18 +36,31 @@ mod helpers;
 extern crate log;
 
 pub struct Tenquestionmarks {
-    subscriptions: BTreeMap<String, Subscription>
+    modules: BTreeMap<String, Module>,
+    subscriptions: MultiMap<String, Subscription>
 }
 
 impl Tenquestionmarks {
     pub fn with_modules (modules: BTreeMap<String, Module>) -> Tenquestionmarks {
-        let tqm = Tenquestionmarks {
+        let mut subscriptions = MultiMap::new();
-            subscriptions: modules.into_iter().map(|(key, module)| {
+        for (name, module) in modules.iter() {
-                (key.clone(), Subscription::new(key.clone(), module))
+            for parent in module.parents() {
-            }).collect()
+                info!("{:?} registered as parent of {:?}", parent, name);
-        };
+                subscriptions.insert(parent, Subscription::new(name.to_owned(), &module));
+            }
 
-        tqm
+            for child_name in module.children() {
+                if let Some(ref child) = modules.get(&child_name) {
+                    info!("{:?} registered as child of {:?}", child_name, name);
+                    subscriptions.insert(name.clone(), Subscription::new(child_name.to_owned(), &child));
+                }
+            }
+        }
+
+        Tenquestionmarks {
+            modules: modules,
+            subscriptions: subscriptions
+        }
     }
 
     pub fn from_configuration (configuration: Table) -> Result<Tenquestionmarks, ModuleLoaderError> {
@@ -65,20 +80,19 @@ impl Tenquestionmarks {
             // into all other Modules.
             // tenquestionmarks propagates all events to each Module through these
             // channels.
-            let module_senders: BTreeMap<&str, Sender<Arc<Envelope>>> = self.subscriptions.iter().map(|(key, subscription)| {
+            let module_senders: BTreeMap<&str, Sender<Arc<Envelope>>> = self.modules.iter().map(|(key, module)| {
                 let from = key.clone();
                 let main_sender_mapped = main_sender.map(move |envelope: Envelope| {
                     Envelope {
                         from: Some(from.clone()),
-                        event: envelope.event,
+                        event: envelope.event
-                        to: envelope.to
                     }
                 });
 
                 let (module_sender, module_receiver) = mpsc::channel();
                 info!("Spawning thread for \"{}\"", key);
                 scope.spawn(move || {
-                    subscription.module.run(Box::new(main_sender_mapped), module_receiver);
+                    module.run(Box::new(main_sender_mapped), module_receiver);
                     info!("Thread for \"{}\" is exiting", key);
                 });
                 (&key[..], module_sender)
@@ -98,16 +112,17 @@ impl Tenquestionmarks {
                          *       names the target module.
                          */
                         let arc_envelope = Arc::new(envelope);
-                        for (key, sender) in &module_senders {
+                        if let Some(ref from) = arc_envelope.from {
-                            let from_this = String::from(*key);
+                            if let Some(subscriptions) = self.subscriptions.get_vec(&**from) {
-                            if let Some(subscription) = self.subscriptions.get::<String>(&from_this) {
+                                for subscription in subscriptions {
-                                if subscription.can_handle_event(&arc_envelope) {
+                                    if subscription.can_handle_event(&arc_envelope) {
-                                    if let Err(err) = sender.send(arc_envelope.clone()) {
+                                        if let Some(sender) = module_senders.get(&*subscription.name) {
-                                        debug!("Failed to dispatch event to module \"{}\": {:?}", key, err);
+                                            if let Err(err) = sender.send(arc_envelope.clone()) {
+                                                debug!("Failed to dispatch event to module \"{}\": {:?}", subscription.name, err);
+                                            }
+                                        }
                                     }
                                 }
-                            } else {
-                                debug!("Failed to dispatch event to module \"{}\": No such module found!", key);
                             }
                         }
                     },
@@ -169,13 +184,12 @@ trait EventFilter: Sync + Send {
 }
 
 struct Subscription {
-    pub module: Module,
     pub name: String,
     pub filters: Vec<Box<EventFilter>>
 }
 
 impl Subscription {
-    pub fn new (name: String, module: Module) -> Subscription {
+    pub fn new (name: String, module: &Module) -> Subscription {
         let filters: Vec<Box<EventFilter>> = module.config.get("filters")
                                                           .and_then(|value| value.as_array())
                                                           .map(|value| value.to_vec())
@@ -192,27 +206,13 @@ impl Subscription {
                                                           .collect();
 
         Subscription {
-            module: module,
             name: name,
             filters: filters
         }
     }
 
     pub fn can_handle_event (&self, envelope: &Envelope) -> bool {
-        if Some(&self.name) == envelope.from.as_ref() {
+        if !self.filters.is_empty() {
-            debug!("Refusing to transmit event to its originator ({:?})", self.name);
-            return false;
-        }
-        else if !(envelope.to.is_empty() || !envelope.to.contains(&self.name)) {
-            debug!(
-                "Refusing to transmit envelope from {:?} to {:?} since it is not on the list of allowed recipients ({:?})",
-                envelope.from,
-                self.name,
-                envelope.to
-            );
-            return false;
-        }
-        else if !self.filters.is_empty() {
             for filter in &self.filters {
                 if filter.accept(envelope) {
                     return true;

src/modules/mod.rs

@@ -10,7 +10,6 @@ pub mod logger;
 
 pub mod loader;
 
-use Tenquestionmarks;
 use event::Envelope;
 
 use std::sync::Arc;
@@ -22,13 +21,37 @@ use toml::value::Table;
 pub struct Module {
     event_loop: Box<EventLoop>,
     module_type: String,
-    pub config: Table
+    pub config: Table,
 }
 
 impl Module {
     pub fn run (&self, sender: Box<ExtSender<Envelope>>, receiver: Receiver<Arc<Envelope>>) {
         self.event_loop.run(sender, receiver);
     }
+
+    pub fn parents (&self) -> Vec<String> {
+        self.config.get("parents")
+                   .and_then(|value| value.as_array())
+                   .map(|value| value.to_vec())
+                   .unwrap_or(vec![])
+                   .iter()
+                   .map(|value| value.as_str())
+                   .filter(|value| value.is_some())
+                   .map(|value| value.unwrap().to_owned())
+                   .collect()
+    }
+
+    pub fn children (&self) -> Vec<String> {
+        self.config.get("children")
+                   .and_then(|value| value.as_array())
+                   .map(|value| value.to_vec())
+                   .unwrap_or(vec![])
+                   .iter()
+                   .map(|value| value.as_str())
+                   .filter(|value| value.is_some())
+                   .map(|value| value.unwrap().to_owned())
+                   .collect()
+    }
 }
 
 pub trait EventLoop : Sync {

tenquestionmarks.toml

@@ -7,10 +7,12 @@ token = "your token here"
 [stdin]
 
 [echo]
+parents = ["stdin", "discord"]
 prefix = "?echo"
 
 [no]
 type = "random"
+parents = ["stdin", "discord"]
 prefix = "?no"
 responses = [
   "https://www.youtube.com/watch?v=WWaLxFIVX1s", # Darth Vader
@@ -36,6 +38,7 @@ responses = [
 
 [yes]
 type = "random"
+parents = ["stdin", "discord"]
 prefix = "?yes"
 responses = [
   "https://www.youtube.com/watch?v=JPVaDaynNKM", # Captain Falcon
@@ -58,14 +61,18 @@ responses = [
 
 [chk]
 type = "random"
+parents = ["stdin", "discord"]
 prefix = "?chk"
 responses = ["ack"]
 
 [pvn]
+parents = ["stdin", "discord"]
 
 [echobox]
+parents = ["stdin", "discord"]
 
 [lua]
+parents = ["stdin", "discord"]
 code = """
 function on_message (message, reply)
     reply("Lua says: " .. message)
@@ -75,6 +82,7 @@ foo = "bar"
 
 [lua2]
 type = "lua"
+parents = ["stdin", "discord"]
 filters = [{ username = "David" }]
 code = """
 function on_message (message, reply)
@@ -83,6 +91,8 @@ end
 """
 
 [autolink]
+parents = ["stdin", "discord"]
 
 [logger]
+parents = ["stdin", "discord"]
 filters = [{ username = "Dave" }, { username = "Kevin" }]