Auto merge of #12685 - ConnorGBrewster:history_length, r=asajeffrey

Implement history.length

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- [X] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).

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components/constellation/constellation.rs

@@ -221,14 +221,16 @@ pub struct InitialConstellationState {
 
 /// Stores the navigation context for a single frame in the frame tree.
 struct Frame {
+    id: FrameId,
     prev: Vec<(PipelineId, Instant)>,
     current: (PipelineId, Instant),
     next: Vec<(PipelineId, Instant)>,
 }
 
 impl Frame {
-    fn new(pipeline_id: PipelineId) -> Frame {
+    fn new(id: FrameId, pipeline_id: PipelineId) -> Frame {
         Frame {
+            id: id,
             prev: vec!(),
             current: (pipeline_id, Instant::now()),
             next: vec!(),
@@ -290,6 +292,37 @@ impl<'a> Iterator for FrameTreeIterator<'a> {
     }
 }
 
+struct FullFrameTreeIterator<'a> {
+    stack: Vec<FrameId>,
+    frames: &'a HashMap<FrameId, Frame>,
+    pipelines: &'a HashMap<PipelineId, Pipeline>,
+}
+
+impl<'a> Iterator for FullFrameTreeIterator<'a> {
+    type Item = &'a Frame;
+    fn next(&mut self) -> Option<&'a Frame> {
+        loop {
+            let frame_id = match self.stack.pop() {
+                Some(frame_id) => frame_id,
+                None => return None,
+            };
+            let frame = match self.frames.get(&frame_id) {
+                Some(frame) => frame,
+                None => {
+                    warn!("Frame {:?} iterated after closure.", frame_id);
+                    continue;
+                },
+            };
+            for &(pipeline_id, _) in frame.prev.iter().chain(frame.next.iter()).chain(once(&frame.current)) {
+                if let Some(pipeline) = self.pipelines.get(&pipeline_id) {
+                    self.stack.extend(pipeline.children.iter().map(|&c| c));
+                }
+            }
+            return Some(frame)
+        }
+    }
+}
+
 struct WebDriverData {
     load_channel: Option<(PipelineId, IpcSender<webdriver_msg::LoadStatus>)>,
     resize_channel: Option<IpcSender<WindowSizeData>>,
@@ -578,77 +611,46 @@ impl<Message, LTF, STF> Constellation<Message, LTF, STF>
         }
     }
 
+    fn full_frame_tree_iter(&self, frame_id_root: FrameId) -> FullFrameTreeIterator {
+        FullFrameTreeIterator {
+            stack: vec!(frame_id_root),
+            pipelines: &self.pipelines,
+            frames: &self.frames,
+        }
+    }
+
     fn joint_session_future(&self, frame_id_root: FrameId) -> Vec<(Instant, FrameId, PipelineId)> {
         let mut future = vec!();
-        self.get_future_entries(frame_id_root, &mut future);
+        for frame in self.full_frame_tree_iter(frame_id_root) {
+            future.extend(frame.next.iter().map(|&(pipeline_id, instant)| (instant, frame.id, pipeline_id)));
+        }
 
         // reverse sorting
         future.sort_by(|a, b| b.cmp(a));
         future
     }
 
-    fn get_future_entries(&self, frame_id_root: FrameId, mut future: &mut Vec<(Instant, FrameId, PipelineId)>) {
-        let frame = match self.frames.get(&frame_id_root) {
-            Some(frame) => frame,
-            None => return warn!("Tried to get frame future after frame {:?} closed.", frame_id_root),
-        };
-
-        future.extend(frame.next.iter().map(|&(pipeline_id, instant)| (instant, frame_id_root, pipeline_id)));
-
-        for &(pipeline_id, _) in frame.next.iter().chain(once(&frame.current)) {
-            let pipeline = match self.pipelines.get(&pipeline_id) {
-                Some(pipeline) => pipeline,
-                None => {
-                    warn!("Tried to get pipeline {:?} for child lookup after closure.", pipeline_id);
-                    continue;
-                }
-            };
-            for &frame_id in &pipeline.children {
-                self.get_future_entries(frame_id, &mut future);
-            }
-        }
-    }
-
     fn joint_session_past(&self, frame_id_root: FrameId) -> Vec<(Instant, FrameId, PipelineId)> {
         let mut past = vec!();
-        self.get_past_entries(frame_id_root, &mut past);
+        for frame in self.full_frame_tree_iter(frame_id_root) {
+            let mut prev_instant = frame.current.1;
+            for &(pipeline_id, instant) in frame.prev.iter().rev() {
+                past.push((prev_instant, frame.id, pipeline_id));
+                prev_instant = instant;
+            }
+        }
 
         past.sort();
         past
     }
 
-    fn get_past_entries(&self, frame_id_root: FrameId, mut past: &mut Vec<(Instant, FrameId, PipelineId)>) {
-        let frame = match self.frames.get(&frame_id_root) {
-            Some(frame) => frame,
-            None => return warn!("Tried to get frame past after frame {:?} closed.", frame_id_root),
-        };
-
-        let mut prev_instant = frame.current.1;
-        for &(pipeline_id, instant) in frame.prev.iter().rev() {
-            past.push((prev_instant, frame_id_root, pipeline_id));
-            prev_instant = instant;
-        }
-        for &(pipeline_id, _) in frame.prev.iter().chain(once(&frame.current)) {
-            let pipeline = match self.pipelines.get(&pipeline_id) {
-                Some(pipeline) => pipeline,
-                None => {
-                    warn!("Tried to get pipeline {:?} for child lookup after closure.", pipeline_id);
-                    continue;
-                }
-            };
-            for frame_id in &pipeline.children {
-                self.get_past_entries(*frame_id, &mut past);
-            }
-        }
-    }
-
     // Create a new frame and update the internal bookkeeping.
     fn new_frame(&mut self, pipeline_id: PipelineId) -> FrameId {
         let id = self.next_frame_id;
         let FrameId(ref mut i) = self.next_frame_id;
         *i += 1;
 
-        let frame = Frame::new(pipeline_id);
+        let frame = Frame::new(id, pipeline_id);
 
         assert!(self.pipelines.get(&pipeline_id).and_then(|pipeline| pipeline.frame).is_none());
         assert!(!self.frames.contains_key(&id));
@@ -831,6 +833,11 @@ impl<Message, LTF, STF> Constellation<Message, LTF, STF>
                 debug!("constellation got traverse history message from script");
                 self.handle_traverse_history_msg(pipeline_id, direction);
             }
+            // Handle a joint session history length request.
+            FromScriptMsg::JointSessionHistoryLength(pipeline_id, sender) => {
+                debug!("constellation got joint session history length message from script");
+                self.handle_joint_session_history_length(pipeline_id, sender);
+            }
             // Notification that the new document is ready to become active
             FromScriptMsg::ActivateDocument(pipeline_id) => {
                 debug!("constellation got activate document message");
@@ -1485,6 +1492,25 @@ impl<Message, LTF, STF> Constellation<Message, LTF, STF>
         }
     }
 
+    fn handle_joint_session_history_length(&self, pipeline_id: PipelineId, sender: IpcSender<u32>) {
+        let frame_id = match self.get_top_level_frame_for_pipeline(Some(pipeline_id)) {
+            Some(frame_id) => frame_id,
+            None => {
+                warn!("Jsh length message received after root's closure.");
+                let _ = sender.send(0);
+                return;
+            },
+        };
+
+        // Initialize length at 1 to count for the current active entry
+        let mut length = 1;
+        for frame in self.full_frame_tree_iter(frame_id) {
+            length += frame.next.len();
+            length += frame.prev.len();
+        }
+        let _ = sender.send(length as u32);
+    }
+
     fn handle_key_msg(&mut self, ch: Option<char>, key: Key, state: KeyState, mods: KeyModifiers) {
         // Send to the explicitly focused pipeline (if it exists), or the root
         // frame's current pipeline. If neither exist, fall back to sending to

components/script/dom/history.rs

@@ -10,6 +10,7 @@ use dom::bindings::global::GlobalRef;
 use dom::bindings::js::{JS, Root};
 use dom::bindings::reflector::{Reflector, reflect_dom_object};
 use dom::window::Window;
+use ipc_channel::ipc;
 use msg::constellation_msg::TraversalDirection;
 use script_traits::ScriptMsg as ConstellationMsg;
 
@@ -44,6 +45,15 @@ impl History {
 }
 
 impl HistoryMethods for History {
+    // https://html.spec.whatwg.org/multipage/#dom-history-length
+    fn Length(&self) -> u32 {
+        let pipeline = self.window.pipeline();
+        let (sender, recv) = ipc::channel().expect("Failed to create channel to send jsh length.");
+        let msg = ConstellationMsg::JointSessionHistoryLength(pipeline, sender);
+        let _ = self.window.constellation_chan().send(msg);
+        recv.recv().unwrap()
+    }
+
     // https://html.spec.whatwg.org/multipage/#dom-history-go
     fn Go(&self, delta: i32) {
         let direction = if delta > 0 {

components/script/dom/webidls/History.webidl

@@ -7,7 +7,7 @@
 // https://html.spec.whatwg.org/multipage/#the-history-interface
 [Exposed=(Window,Worker)]
 interface History {
-  // readonly attribute unsigned long length;
+  readonly attribute unsigned long length;
   // attribute ScrollRestoration scrollRestoration;
   // readonly attribute any state;
   void go(optional long delta = 0);

components/script_traits/script_msg.rs

@@ -91,6 +91,8 @@ pub enum ScriptMsg {
     MozBrowserEvent(PipelineId, Option<SubpageId>, MozBrowserEvent),
     /// HTMLIFrameElement Forward or Back traversal.
     TraverseHistory(Option<PipelineId>, TraversalDirection),
+    /// Gets the length of the joint session history from the constellation.
+    JointSessionHistoryLength(PipelineId, IpcSender<u32>),
     /// Favicon detected
     NewFavicon(Url),
     /// Status message to be displayed in the chrome, eg. a link URL on mouseover.

tests/wpt/metadata/html/browsers/history/the-history-interface/001.html.ini

@@ -1,8 +1,5 @@
 [001.html]
   type: testharness
-  [history.length should update when loading pages in an iframe]
-    expected: FAIL
-
   [history.length should update when setting location.hash]
     expected: FAIL
 

tests/wpt/metadata/html/browsers/history/the-history-interface/002.html.ini

@@ -1,8 +1,5 @@
 [002.html]
   type: testharness
-  [history.length should update when loading pages in an iframe]
-    expected: FAIL
-
   [history.length should update when setting location.hash]
     expected: FAIL
 

tests/wpt/metadata/html/browsers/history/the-location-interface/location_assign_about_blank.html.ini

@@ -0,0 +1,5 @@
+[location_assign_about_blank.html]
+  type: testharness
+  [location.assign with initial about:blank browsing context]
+    expected: FAIL
+

tests/wpt/metadata/html/dom/interfaces.html.ini

@@ -5598,9 +5598,6 @@
   [BarProp interface: attribute visible]
     expected: FAIL
 
-  [History interface: attribute length]
-    expected: FAIL
-
   [History interface: attribute state]
     expected: FAIL
 
@@ -5610,9 +5607,6 @@
   [History interface: operation replaceState(any,DOMString,DOMString)]
     expected: FAIL
 
-  [History interface: window.history must inherit property "length" with the proper type (0)]
-    expected: FAIL
-
   [History interface: window.history must inherit property "state" with the proper type (1)]
     expected: FAIL