Introduce DOMTracker, cancel eventsource fetch when aborting document load

1 files changed, 40 insertions, 14 deletions

diff --git a/components/script/dom/eventsource.rs b/components/script/dom/eventsource.rs
index 48b762978ca..072a3dd0080 100644
--- a/components/script/dom/eventsource.rs
+++ b/components/script/dom/eventsource.rs
@@ -16,6 +16,7 @@ use dom::globalscope::GlobalScope;
 use dom::messageevent::MessageEvent;
 use dom_struct::dom_struct;
 use euclid::Length;
+use fetch::FetchCanceller;
 use hyper::header::{Accept, qitem};
 use ipc_channel::ipc;
 use ipc_channel::router::ROUTER;
@@ -64,6 +65,7 @@ pub struct EventSource {
 
     ready_state: Cell<ReadyState>,
     with_credentials: bool,
+    canceller: DomRefCell<FetchCanceller>,
 }
 
 enum ParserState {
@@ -118,19 +120,7 @@ impl EventSourceContext {
         if self.gen_id != event_source.generation_id.get() {
             return;
         }
-        let global = event_source.global();
-        let event_source = self.event_source.clone();
-        // FIXME(nox): Why are errors silenced here?
-        let _ = global.remote_event_task_source().queue(
-            task!(fail_the_event_source_connection: move || {
-                let event_source = event_source.root();
-                if event_source.ready_state.get() != ReadyState::Closed {
-                    event_source.ready_state.set(ReadyState::Closed);
-                    event_source.upcast::<EventTarget>().fire_event(atom!("error"));
-                }
-            }),
-            &global,
-        );
+        event_source.fail_the_connection();
     }
 
     // https://html.spec.whatwg.org/multipage/#reestablish-the-connection
@@ -410,6 +400,7 @@ impl EventSource {
 
             ready_state: Cell::new(ReadyState::Connecting),
             with_credentials: with_credentials,
+            canceller: DomRefCell::new(Default::default())
         }
     }
 
@@ -419,6 +410,29 @@ impl EventSource {
                            Wrap)
     }
 
+    // https://html.spec.whatwg.org/multipage/#sse-processing-model:fail-the-connection-3
+    pub fn cancel(&self) {
+        self.canceller.borrow_mut().cancel();
+        self.fail_the_connection();
+    }
+
+    /// <https://html.spec.whatwg.org/multipage/#fail-the-connection>
+    pub fn fail_the_connection(&self) {
+        let global = self.global();
+        let event_source = Trusted::new(self);
+        // FIXME(nox): Why are errors silenced here?
+        let _ = global.remote_event_task_source().queue(
+            task!(fail_the_event_source_connection: move || {
+                let event_source = event_source.root();
+                if event_source.ready_state.get() != ReadyState::Closed {
+                    event_source.ready_state.set(ReadyState::Closed);
+                    event_source.upcast::<EventTarget>().fire_event(atom!("error"));
+                }
+            }),
+            &global,
+        );
+    }
+
     pub fn request(&self) -> RequestInit {
         self.request.borrow().clone().unwrap()
     }
@@ -437,6 +451,7 @@ impl EventSource {
         };
         // Step 1, 5
         let ev = EventSource::new(global, url_record.clone(), event_source_init.withCredentials);
+        global.track_event_source(&ev);
         // Steps 6-7
         let cors_attribute_state = if event_source_init.withCredentials {
             CorsSettings::UseCredentials
@@ -491,13 +506,23 @@ impl EventSource {
         ROUTER.add_route(action_receiver.to_opaque(), Box::new(move |message| {
             listener.notify_fetch(message.to().unwrap());
         }));
+        let cancel_receiver = ev.canceller.borrow_mut().initialize();
         global.core_resource_thread().send(
-            CoreResourceMsg::Fetch(request, FetchChannels::ResponseMsg(action_sender, None))).unwrap();
+            CoreResourceMsg::Fetch(request, FetchChannels::ResponseMsg(action_sender, Some(cancel_receiver)))).unwrap();
         // Step 13
         Ok(ev)
     }
 }
 
+// https://html.spec.whatwg.org/multipage/#garbage-collection-2
+impl Drop for EventSource {
+    fn drop(&mut self) {
+        // If an EventSource object is garbage collected while its connection is still open,
+        // the user agent must abort any instance of the fetch algorithm opened by this EventSource.
+        self.canceller.borrow_mut().cancel();
+    }
+}
+
 impl EventSourceMethods for EventSource {
     // https://html.spec.whatwg.org/multipage/#handler-eventsource-onopen
     event_handler!(open, GetOnopen, SetOnopen);
@@ -527,6 +552,7 @@ impl EventSourceMethods for EventSource {
     fn Close(&self) {
         let GenerationId(prev_id) = self.generation_id.get();
         self.generation_id.set(GenerationId(prev_id + 1));
+        self.canceller.borrow_mut().cancel();
         self.ready_state.set(ReadyState::Closed);
     }
 }