Bug 1759744 - Add support for page load event telemetry r=smaug,chutten

Differential Revision: https://phabricator.services.mozilla.com/D141369

dom/base/Document.cpp

@@ -240,6 +240,7 @@
 #include "mozilla/gfx/Coord.h"
 #include "mozilla/gfx/Point.h"
 #include "mozilla/gfx/ScaleFactor.h"
+#include "mozilla/glean/GleanMetrics.h"
 #include "mozilla/intl/LocaleService.h"
 #include "mozilla/ipc/IdleSchedulerChild.h"
 #include "mozilla/ipc/MessageChannel.h"
@@ -278,6 +279,7 @@
 #include "nsDOMString.h"
 #include "nsDeviceContext.h"
 #include "nsDocShell.h"
+#include "nsDocShellLoadTypes.h"
 #include "nsError.h"
 #include "nsEscape.h"
 #include "nsFocusManager.h"
@@ -1981,12 +1983,19 @@ void Document::ConstructUbiNode(void* storage) {
 }
 
 void Document::LoadEventFired() {
+  // Object used to collect some telemetry data so we don't need to query for it
+  // twice.
+  PageLoadEventTelemetryData pageLoadEventData;
+
   // Accumulate timing data located in each document's realm and report to
   // telemetry.
-  AccumulateJSTelemetry();
+  AccumulateJSTelemetry(pageLoadEventData);
 
   // Collect page load timings
-  AccumulatePageLoadTelemetry();
+  AccumulatePageLoadTelemetry(pageLoadEventData);
+
+  // Record page load event
+  RecordPageLoadEventTelemetry(pageLoadEventData);
 
   // Release the JS bytecode cache from its wait on the load event, and
   // potentially dispatch the encoding of the bytecode.
@@ -1995,7 +2004,85 @@ void Document::LoadEventFired() {
   }
 }
 
-void Document::AccumulatePageLoadTelemetry() {
+void Document::RecordPageLoadEventTelemetry(
+    PageLoadEventTelemetryData aEventTelemetryData) {
+  static bool sTelemetryEventEnabled = false;
+  if (!sTelemetryEventEnabled) {
+    sTelemetryEventEnabled = true;
+    Telemetry::SetEventRecordingEnabled("page_load"_ns, true);
+  }
+
+  // If the page load time is empty, then the content wasn't something we want
+  // to report (i.e. not a top level document).
+  if (!aEventTelemetryData.mPageLoadTime ||
+      aEventTelemetryData.mPageLoadTime.IsZero()) {
+    return;
+  }
+  MOZ_ASSERT(IsTopLevelContentDocument());
+
+  nsPIDOMWindowOuter* window = GetWindow();
+  if (!window) {
+    return;
+  }
+
+  nsIDocShell* docshell = window->GetDocShell();
+  if (!docshell) {
+    return;
+  }
+
+  nsAutoCString loadTypeStr;
+  switch (docshell->GetLoadType()) {
+    case LOAD_NORMAL:
+    case LOAD_NORMAL_REPLACE:
+    case LOAD_NORMAL_BYPASS_CACHE:
+    case LOAD_NORMAL_BYPASS_PROXY:
+    case LOAD_NORMAL_BYPASS_PROXY_AND_CACHE:
+      loadTypeStr.Append("NORMAL");
+      break;
+    case LOAD_HISTORY:
+      loadTypeStr.Append("HISTORY");
+      break;
+    case LOAD_RELOAD_NORMAL:
+    case LOAD_RELOAD_BYPASS_CACHE:
+    case LOAD_RELOAD_BYPASS_PROXY:
+    case LOAD_RELOAD_BYPASS_PROXY_AND_CACHE:
+    case LOAD_REFRESH:
+    case LOAD_REFRESH_REPLACE:
+    case LOAD_RELOAD_CHARSET_CHANGE:
+    case LOAD_RELOAD_CHARSET_CHANGE_BYPASS_PROXY_AND_CACHE:
+    case LOAD_RELOAD_CHARSET_CHANGE_BYPASS_CACHE:
+      loadTypeStr.Append("RELOAD");
+      break;
+    case LOAD_LINK:
+      loadTypeStr.Append("LINK");
+      break;
+    case LOAD_STOP_CONTENT:
+    case LOAD_STOP_CONTENT_AND_REPLACE:
+      loadTypeStr.Append("STOP");
+      break;
+    case LOAD_ERROR_PAGE:
+      loadTypeStr.Append("ERROR");
+      break;
+    default:
+      loadTypeStr.Append("OTHER");
+      break;
+  }
+
+  mozilla::glean::perf::PageLoadExtra extra = {
+      mozilla::Some(static_cast<uint32_t>(
+          aEventTelemetryData.mFirstContentfulPaintTime.ToMilliseconds())),
+      mozilla::Some(static_cast<uint32_t>(
+          aEventTelemetryData.mTotalJSExecutionTime.ToMilliseconds())),
+      mozilla::Some(static_cast<uint32_t>(
+          aEventTelemetryData.mPageLoadTime.ToMilliseconds())),
+      mozilla::Some(loadTypeStr),
+      mozilla::Some(static_cast<uint32_t>(
+          aEventTelemetryData.mResponseStartTime.ToMilliseconds()))};
+  mozilla::glean::perf::page_load.Record(mozilla::Some(extra));
+}
+
+void Document::AccumulatePageLoadTelemetry(
+    PageLoadEventTelemetryData& aEventTelemetryDataOut) {
   // Interested only in top level documents for real websites that are in the
   // foreground.
   if (!ShouldIncludeInTelemetry(false) || !IsTopLevelContentDocument() ||
@@ -2076,6 +2163,9 @@ void Document::AccumulatePageLoadTelemetry() {
     Telemetry::AccumulateTimeDelta(
         Telemetry::PERF_FIRST_CONTENTFUL_PAINT_FROM_RESPONSESTART_MS,
         responseStart, firstContentfulComposite);
+
+    aEventTelemetryDataOut.mFirstContentfulPaintTime =
+        firstContentfulComposite - navigationStart;
   }
 
   // DOM Content Loaded event
@@ -2107,10 +2197,14 @@ void Document::AccumulatePageLoadTelemetry() {
     Telemetry::AccumulateTimeDelta(
         Telemetry::PERF_PAGE_LOAD_TIME_FROM_RESPONSESTART_MS, responseStart,
         loadEventStart);
+
+    aEventTelemetryDataOut.mResponseStartTime = responseStart - navigationStart;
+    aEventTelemetryDataOut.mPageLoadTime = loadEventStart - navigationStart;
   }
 }
 
-void Document::AccumulateJSTelemetry() {
+void Document::AccumulateJSTelemetry(
+    PageLoadEventTelemetryData& aEventTelemetryDataOut) {
   if (!IsTopLevelContentDocument() || !ShouldIncludeInTelemetry(false)) {
     return;
   }
@@ -2128,6 +2222,7 @@ void Document::AccumulateJSTelemetry() {
     Telemetry::Accumulate(
         Telemetry::JS_PAGELOAD_EXECUTION_MS,
         static_cast<uint32_t>(timers.executionTime.ToMilliseconds()));
+    aEventTelemetryDataOut.mTotalJSExecutionTime = timers.executionTime;
   }
 
   if (!timers.delazificationTime.IsZero()) {

dom/base/Document.h

@@ -338,6 +338,12 @@ class DOMStyleSheetSetList;
 class ResizeObserver;
 class ResizeObserverController;
 class PostMessageEvent;
+struct PageLoadEventTelemetryData {
+  TimeDuration mPageLoadTime;
+  TimeDuration mTotalJSExecutionTime;
+  TimeDuration mResponseStartTime;
+  TimeDuration mFirstContentfulPaintTime;
+};
 
 #define DEPRECATED_OPERATION(_op) e##_op,
 enum class DeprecatedOperations : uint16_t {
@@ -5280,11 +5286,17 @@ class Document : public nsINode,
   // See SetNotifyFormOrPasswordRemoved and ShouldNotifyFormOrPasswordRemoved.
   bool mShouldNotifyFormOrPasswordRemoved;
 
+  // Record page load telemetry
+  void RecordPageLoadEventTelemetry(
+      PageLoadEventTelemetryData aEventTelemetryData);
+
   // Accumulate JS telemetry collected
-  void AccumulateJSTelemetry();
+  void AccumulateJSTelemetry(
+      PageLoadEventTelemetryData& aEventTelemetryDataOut);
 
   // Accumulate page load metrics
-  void AccumulatePageLoadTelemetry();
+  void AccumulatePageLoadTelemetry(
+      PageLoadEventTelemetryData& aEventTelemetryDataOut);
 
   // The OOP counterpart to nsDocLoader::mChildrenInOnload.
   // Not holding strong refs here since we don't actually use the BBCs.

dom/metrics.yaml

@@ -0,0 +1,55 @@
+# 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/.
+
+# This file defines the metrics that are recorded by the Glean SDK. They are
+# automatically converted to platform-specific code at build time using the
+# `glean_parser` PyPI package.
+
+# Adding a new metric? We have docs for that!
+# https://firefox-source-docs.mozilla.org/toolkit/components/glean/user/new_definitions_file.html
+
+---
+$schema: moz://mozilla.org/schemas/glean/metrics/2-0-0
+$tags:
+  - 'Core :: DOM: Core & HTML'
+
+perf:
+  page_load:
+    type: event
+    description: >
+        Recorded when a top level content document has been loaded.
+    bugs:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1759744
+    data_reviews:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1759744#c5
+    notification_emails:
+      - perf-telemetry-alerts@mozilla.com
+      - dpalmeiro@mozilla.com
+    expires: never
+    extra_keys:
+      load_time:
+        description:
+          "Time between loadEventStart and navigationStart, in ms."
+        type: quantity
+        unit: ms
+      response_time:
+        description:
+          "Time between responseStart and navigationStart, in ms."
+        type: quantity
+        unit: ms
+      fcp_time:
+        description:
+          "Time between firstContentfulPaint and naviationStart, in ms."
+        type: quantity
+        unit: ms
+      js_exec_time:
+        description:
+          "Time spent executing JS during page load, in ms."
+        type: quantity
+        unit: ms
+      load_type:
+        description:
+          "One of normal,reload,stop,link,history,error or other."
+        type: string
+    telemetry_mirror: Page_load_Toplevel_Content

toolkit/components/glean/metrics_index.py

@@ -23,6 +23,7 @@ metrics_yamls = [
     "browser/modules/metrics.yaml",
     "browser/components/metrics.yaml",
     "toolkit/components/telemetry/metrics.yaml",
+    "dom/metrics.yaml",
 ]
 
 # The list of all Glean pings.yaml files, relative to the top src dir.

toolkit/components/telemetry/Events.yaml

@@ -2897,6 +2897,28 @@ slow_script_warning:
       uri_type: The kind of script URL that hung.
       uptime: How long the notification was up (ms).
 
+page_load:
+  toplevel:
+    bug_numbers:
+      - 1759744
+    description: >
+      Recorded when a top level content document has been loaded.
+    products:
+      - "firefox"
+    record_in_processes: ["content"]
+    release_channel_collection: opt-out
+    expiry_version: "never"
+    notification_emails:
+      - dpalmeiro@mozilla.com
+      - perf-telemetry-alerts@mozilla.com
+    objects: ["content"]
+    extra_keys:
+      load_time: Time between loadEventStart and navigationStart, in ms.
+      response_time: Time between responseStart and navigationStart, in ms.
+      fcp_time: Time between firstContentfulPaint and navigationStart, in ms.
+      js_exec_time: Time spent executing JS during page load, in ms.
+      load_type: One of normal,reload,stop,link,history,error or other.
+
 webrtc.ui:
   show_indicator:
     objects: ["show_indicator"]