servo: Merge #18155 - Add paint metrics to Performance Timeline API (from ferjm:pwm.perf.timeline); r=jdm

- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #18111
- [X] There are tests for these changes

Source-Repo: https://github.com/servo/servo
Source-Revision: 173079c14498f0ef4810ffbaf8f4c03acf557eed

--HG--
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
extra : subtree_revision : d8d05c7c5ce7cf26797aa8633f8459aaf472fff3

servo/components/constellation/pipeline.rs

@@ -488,7 +488,8 @@ impl UnprivilegedPipelineContent {
         let image_cache = Arc::new(ImageCacheImpl::new(self.webrender_api_sender.create_api()));
         let paint_time_metrics = PaintTimeMetrics::new(self.id,
                                                        self.time_profiler_chan.clone(),
-                                                       self.layout_to_constellation_chan.clone());
+                                                       self.layout_to_constellation_chan.clone(),
+                                                       self.script_chan.clone());
         let layout_pair = STF::create(InitialScriptState {
             id: self.id,
             browsing_context_id: self.browsing_context_id,

servo/components/metrics/lib.rs

@@ -18,7 +18,7 @@ use ipc_channel::ipc::IpcSender;
 use msg::constellation_msg::PipelineId;
 use profile_traits::time::{ProfilerChan, ProfilerCategory, send_profile_data};
 use profile_traits::time::TimerMetadata;
-use script_traits::LayoutMsg;
+use script_traits::{ConstellationControlMsg, LayoutMsg, PaintMetricType};
 use servo_config::opts;
 use std::cell::{Cell, RefCell};
 use std::collections::HashMap;
@@ -28,8 +28,10 @@ pub trait ProfilerMetadataFactory {
 }
 
 macro_rules! make_time_setter(
-    ( $attr:ident, $func:ident, $category:ident, $label:expr ) => (
-        fn $func(&self, profiler_metadata: Option<TimerMetadata>, paint_time: f64) {
+    ( $attr:ident, $func:ident, $category:ident, $label:expr, $metric_type:path ) => (
+        fn $func(&self,
+                 profiler_metadata: Option<TimerMetadata>,
+                 paint_time: f64) {
             if self.$attr.get().is_some() {
                 return;
             }
@@ -45,6 +47,14 @@ macro_rules! make_time_setter(
             let time = paint_time - navigation_start;
             self.$attr.set(Some(time));
 
+            // Queue performance observer notification.
+            let msg = ConstellationControlMsg::PaintMetric(self.pipeline_id,
+                                                           $metric_type,
+                                                           time);
+            if let Err(e) = self.script_chan.send(msg) {
+                warn!("Sending paint metric to script thread failed ({}).", e);
+            }
+
             // Send the metric to the time profiler.
             send_profile_data(ProfilerCategory::$category,
                               profiler_metadata,
@@ -67,12 +77,14 @@ pub struct PaintTimeMetrics {
     pipeline_id: PipelineId,
     time_profiler_chan: ProfilerChan,
     constellation_chan: IpcSender<LayoutMsg>,
+    script_chan: IpcSender<ConstellationControlMsg>,
 }
 
 impl PaintTimeMetrics {
     pub fn new(pipeline_id: PipelineId,
                time_profiler_chan: ProfilerChan,
-               constellation_chan: IpcSender<LayoutMsg>)
+               constellation_chan: IpcSender<LayoutMsg>,
+               script_chan: IpcSender<ConstellationControlMsg>)
         -> PaintTimeMetrics {
         PaintTimeMetrics {
             pending_metrics: RefCell::new(HashMap::new()),
@@ -82,6 +94,7 @@ impl PaintTimeMetrics {
             pipeline_id,
             time_profiler_chan,
             constellation_chan,
+            script_chan,
         }
     }
 
@@ -91,10 +104,12 @@ impl PaintTimeMetrics {
 
     make_time_setter!(first_paint, set_first_paint,
                       TimeToFirstPaint,
-                      "first-paint");
+                      "first-paint",
+                      PaintMetricType::FirstPaint);
     make_time_setter!(first_contentful_paint, set_first_contentful_paint,
                       TimeToFirstContentfulPaint,
-                      "first-contentful-paint");
+                      "first-contentful-paint",
+                      PaintMetricType::FirstContentfulPaint);
 
     pub fn maybe_observe_paint_time<T>(&self,
                                        profiler_metadata_factory: &T,

servo/components/script/dom/mod.rs

@@ -401,6 +401,7 @@ pub mod performance;
 pub mod performanceentry;
 pub mod performanceobserver;
 pub mod performanceobserverentrylist;
+pub mod performancepainttiming;
 pub mod performancetiming;
 pub mod permissions;
 pub mod permissionstatus;

servo/components/script/dom/performanceentry.rs

@@ -21,10 +21,10 @@ pub struct PerformanceEntry {
 }
 
 impl PerformanceEntry {
-    fn new_inherited(name: DOMString,
-                     entry_type: DOMString,
-                     start_time: f64,
-                     duration: f64) -> PerformanceEntry {
+    pub fn new_inherited(name: DOMString,
+                         entry_type: DOMString,
+                         start_time: f64,
+                         duration: f64) -> PerformanceEntry {
         PerformanceEntry {
             reflector_: Reflector::new(),
             name,

servo/components/script/dom/performanceobserver.rs

@@ -27,7 +27,7 @@ const VALID_ENTRY_TYPES: &'static [&'static str] = &[
     // "measure", XXX User Timing API
     // "resource", XXX Resource Timing API
     // "server", XXX Server Timing API
-    // "paint", XXX Paint Timing API
+    "paint", // Paint Timing API
 ];
 
 #[dom_struct]

servo/components/script/dom/performancepainttiming.rs

@@ -0,0 +1,41 @@
+/* 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/. */
+
+use dom::bindings::codegen::Bindings::PerformancePaintTimingBinding;
+use dom::bindings::js::Root;
+use dom::bindings::reflector::reflect_dom_object;
+use dom::bindings::str::DOMString;
+use dom::globalscope::GlobalScope;
+use dom::performanceentry::PerformanceEntry;
+use dom_struct::dom_struct;
+use script_traits::PaintMetricType;
+
+#[dom_struct]
+pub struct PerformancePaintTiming {
+    entry: PerformanceEntry,
+}
+
+impl PerformancePaintTiming {
+    fn new_inherited(metric_type: PaintMetricType, start_time: f64)
+        -> PerformancePaintTiming {
+        let name = match metric_type {
+            PaintMetricType::FirstPaint => DOMString::from("first-paint"),
+            PaintMetricType::FirstContentfulPaint => DOMString::from("first-contentful-paint"),
+        };
+        PerformancePaintTiming {
+            entry: PerformanceEntry::new_inherited(name,
+                                                   DOMString::from("paint"),
+                                                   start_time,
+                                                   0.)
+        }
+    }
+
+    #[allow(unrooted_must_root)]
+    pub fn new(global: &GlobalScope,
+               metric_type: PaintMetricType,
+               start_time: f64) -> Root<PerformancePaintTiming> {
+        let entry = PerformancePaintTiming::new_inherited(metric_type, start_time);
+        reflect_dom_object(box entry, global, PerformancePaintTimingBinding::Wrap)
+    }
+}

servo/components/script/dom/webidls/PerformancePaintTiming.webidl

@@ -0,0 +1,11 @@
+/* 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/.
+ *
+ * The origin of this IDL file is
+ * https://wicg.github.io/paint-timing/#sec-PerformancePaintTiming
+ */
+
+[Exposed=(Window,Worker)]
+interface PerformancePaintTiming : PerformanceEntry {
+};

servo/components/script/script_thread.rs

@@ -49,6 +49,8 @@ use dom::htmlanchorelement::HTMLAnchorElement;
 use dom::htmliframeelement::{HTMLIFrameElement, NavigationType};
 use dom::mutationobserver::MutationObserver;
 use dom::node::{Node, NodeDamage, window_from_node, from_untrusted_node_address};
+use dom::performanceentry::PerformanceEntry;
+use dom::performancepainttiming::PerformancePaintTiming;
 use dom::serviceworker::TrustedServiceWorkerAddress;
 use dom::serviceworkerregistration::ServiceWorkerRegistration;
 use dom::servoparser::{ParserContext, ServoParser};
@@ -85,7 +87,7 @@ use profile_traits::time::{self, ProfilerCategory, profile};
 use script_layout_interface::message::{self, Msg, NewLayoutThreadInfo, ReflowQueryType};
 use script_runtime::{CommonScriptMsg, ScriptChan, ScriptThreadEventCategory};
 use script_runtime::{ScriptPort, StackRootTLS, get_reports, new_rt_and_cx};
-use script_traits::{CompositorEvent, ConstellationControlMsg};
+use script_traits::{CompositorEvent, ConstellationControlMsg, PaintMetricType};
 use script_traits::{DocumentActivity, DiscardBrowsingContext, EventResult};
 use script_traits::{InitialScriptState, LayoutMsg, LoadData, MouseButton, MouseEventType, MozBrowserEvent};
 use script_traits::{NewLayoutInfo, ScriptToConstellationChan, ScriptMsg, UpdatePipelineIdReason};
@@ -1261,6 +1263,8 @@ impl ScriptThread {
                 self.handle_exit_pipeline_msg(pipeline_id, discard_browsing_context),
             ConstellationControlMsg::WebVREvents(pipeline_id, events) =>
                 self.handle_webvr_events(pipeline_id, events),
+            ConstellationControlMsg::PaintMetric(pipeline_id, metric_type, metric_value) =>
+                self.handle_paint_metric(pipeline_id, metric_type, metric_value),
             msg @ ConstellationControlMsg::AttachLayout(..) |
             msg @ ConstellationControlMsg::Viewport(..) |
             msg @ ConstellationControlMsg::SetScrollState(..) |
@@ -1482,7 +1486,8 @@ impl ScriptThread {
             layout_threads: layout_threads,
             paint_time_metrics: PaintTimeMetrics::new(new_pipeline_id,
                                                       self.time_profiler_chan.clone(),
-                                                      self.layout_to_constellation_chan.clone()),
+                                                      self.layout_to_constellation_chan.clone(),
+                                                      self.control_chan.clone()),
         });
 
         // Pick a layout thread, any layout thread
@@ -2485,6 +2490,19 @@ impl ScriptThread {
         }
     }
 
+    fn handle_paint_metric(&self,
+                           pipeline_id: PipelineId,
+                           metric_type: PaintMetricType,
+                           metric_value: f64) {
+        let window = self.documents.borrow().find_window(pipeline_id);
+        if let Some(window) = window {
+            let entry = PerformancePaintTiming::new(&window.upcast::<GlobalScope>(),
+                                                    metric_type, metric_value);
+            window.Performance().queue_entry(&entry.upcast::<PerformanceEntry>(),
+                                             true /* buffer performance entry */);
+        }
+    }
+
     pub fn enqueue_microtask(job: Microtask) {
         SCRIPT_THREAD_ROOT.with(|root| {
             let script_thread = unsafe { &*root.get().unwrap() };

servo/components/script_traits/lib.rs

@@ -220,6 +220,15 @@ pub enum DocumentActivity {
     FullyActive,
 }
 
+/// The type of recorded paint metric.
+#[derive(Deserialize, Serialize)]
+pub enum PaintMetricType {
+    /// Time to First Paint type.
+    FirstPaint,
+    /// Time to First Contentful Paint type.
+    FirstContentfulPaint,
+}
+
 /// The reason why the pipeline id of an iframe is being updated.
 #[derive(Copy, Clone, PartialEq, Eq, Hash, HeapSizeOf, Debug, Deserialize, Serialize)]
 pub enum UpdatePipelineIdReason {
@@ -300,7 +309,9 @@ pub enum ConstellationControlMsg {
     /// Reload the given page.
     Reload(PipelineId),
     /// Notifies the script thread of WebVR events.
-    WebVREvents(PipelineId, Vec<WebVREvent>)
+    WebVREvents(PipelineId, Vec<WebVREvent>),
+    /// Notifies the script thread about a new recorded paint metric.
+    PaintMetric(PipelineId, PaintMetricType, f64),
 }
 
 impl fmt::Debug for ConstellationControlMsg {
@@ -334,6 +345,7 @@ impl fmt::Debug for ConstellationControlMsg {
             ReportCSSError(..) => "ReportCSSError",
             Reload(..) => "Reload",
             WebVREvents(..) => "WebVREvents",
+            PaintMetric(..) => "PaintMetric",
         };
         write!(formatter, "ConstellationMsg::{}", variant)
     }

servo/python/tidy/servo_tidy/tidy.py

@@ -79,6 +79,7 @@ WEBIDL_STANDARDS = [
     "//heycam.github.io/webidl",
     "//webbluetoothcg.github.io/web-bluetooth/",
     "//svgwg.org/svg2-draft",
+    "//wicg.github.io",
     # Not a URL
     "// This interface is entirely internal to Servo, and should not be" +
     " accessible to\n// web pages."

servo/tests/unit/metrics/paint_time.rs

@@ -30,7 +30,8 @@ fn test_paint_metrics_construction() {
     let (sender, _) = ipc::channel().unwrap();
     let profiler_chan = ProfilerChan(sender);
     let (layout_sender, _) = ipc::channel().unwrap();
-    let paint_time_metrics = PaintTimeMetrics::new(pipeline_id, profiler_chan, layout_sender);
+    let (script_sender, _) = ipc::channel().unwrap();
+    let paint_time_metrics = PaintTimeMetrics::new(pipeline_id, profiler_chan, layout_sender, script_sender);
     assert_eq!(paint_time_metrics.get_navigation_start(), None, "navigation start is None");
     assert_eq!(paint_time_metrics.get_first_paint(), None, "first paint is None");
     assert_eq!(paint_time_metrics.get_first_contentful_paint(), None, "first contentful paint is None");
@@ -44,7 +45,8 @@ fn test_common(display_list: &DisplayList, epoch: Epoch) -> PaintTimeMetrics {
     let (sender, _) = ipc::channel().unwrap();
     let profiler_chan = ProfilerChan(sender);
     let (layout_sender, _) = ipc::channel().unwrap();
-    let mut paint_time_metrics = PaintTimeMetrics::new(pipeline_id, profiler_chan, layout_sender);
+    let (script_sender, _) = ipc::channel().unwrap();
+    let mut paint_time_metrics = PaintTimeMetrics::new(pipeline_id, profiler_chan, layout_sender, script_sender);
     let dummy_profiler_metadata_factory = DummyProfilerMetadataFactory {};
 
     paint_time_metrics.maybe_observe_paint_time(&dummy_profiler_metadata_factory,