// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
package org.chromium.chrome.browser.metrics;
import android.os.SystemClock;
import org.chromium.base.TraceEvent;
import org.chromium.base.metrics.RecordHistogram;
import org.chromium.base.metrics.RecordUserAction;
import org.chromium.base.supplier.ObservableSupplier;
import org.chromium.chrome.browser.flags.ActivityType;
import org.chromium.chrome.browser.page_load_metrics.PageLoadMetrics;
import org.chromium.chrome.browser.paint_preview.StartupPaintPreviewHelper;
import org.chromium.chrome.browser.paint_preview.StartupPaintPreviewMetrics.PaintPreviewMetricsObserver;
import org.chromium.chrome.browser.tab.Tab;
import org.chromium.chrome.browser.tabmodel.TabModelSelector;
import org.chromium.chrome.browser.tabmodel.TabModelSelectorTabObserver;
import org.chromium.components.embedder_support.util.UrlUtilities;
import org.chromium.components.safe_browsing.SafeBrowsingApiBridge;
import org.chromium.content_public.browser.NavigationHandle;
import org.chromium.content_public.browser.WebContents;
import org.chromium.url.GURL;
import java.util.concurrent.atomic.AtomicLong;
/**
* Tracks the first navigation and first contentful paint events for a tab within an activity during
* startup.
*/
public class LegacyTabStartupMetricsTracker {
private static final String FIRST_COMMIT_OCCURRED_PRE_FOREGROUND_HISTOGRAM =
"Startup.Android.Cold.FirstNavigationCommitOccurredPreForeground";
private static final String FIRST_PAINT_OCCURRED_PRE_FOREGROUND_HISTOGRAM =
"Startup.Android.Cold.FirstPaintOccurredPreForeground";
private class PageLoadMetricsObserverImpl implements PageLoadMetrics.Observer {
private static final long NO_NAVIGATION_ID = -1;
private long mNavigationId = NO_NAVIGATION_ID;
private boolean mShouldRecordHistograms;
@Override
public void onNewNavigation(
WebContents webContents,
long navigationId,
boolean isFirstNavigationInWebContents) {
if (mNavigationId != NO_NAVIGATION_ID) return;
mNavigationId = navigationId;
mShouldRecordHistograms = mShouldTrackStartupMetrics;
}
@Override
public void onFirstContentfulPaint(
WebContents webContents,
long navigationId,
long navigationStartMicros,
long firstContentfulPaintMs) {
if (navigationId != mNavigationId || !mShouldRecordHistograms) return;
recordFirstContentfulPaint(navigationStartMicros / 1000 + firstContentfulPaintMs);
}
}
// The time of the activity onCreate(). All metrics (such as time to first visible content) are
// reported in milliseconds relative to this value.
private final long mActivityStartTimeMs;
private final long mActivityId;
// Event duration recorded from the |mActivityStartTimeMs|.
private long mFirstCommitTimeMs;
private @ActivityType int mHistogramSuffix;
private TabModelSelectorTabObserver mTabModelSelectorTabObserver;
private PageLoadMetricsObserverImpl mPageLoadMetricsObserver;
private boolean mShouldTrackStartupMetrics;
private boolean mFirstVisibleContentRecorded;
private boolean mFirstVisibleContent2Recorded;
private boolean mVisibleContentRecorded;
private boolean mBackPressOccurred;
// Records whether the tracked first navigation commit was recorded pre-the app being in the
// foreground. Used for investigating crbug.com/1273097.
private boolean mRegisteredFirstCommitPreForeground;
// Records whether StartupPaintPreview's first paint was recorded pre-the app being in the
// foreground. Used for investigating crbug.com/1273097.
private boolean mRegisteredFirstPaintPreForeground;
// The time it took for SafetyNet API to return a Safe Browsing response for the first time. The
// SB request is on the critical path to navigation commit, and the response may be severely
// delayed by GmsCore (see http://crbug.com/1296097). The value is recorded only when the
// navigation commits successfully and the URL of first navigation is checked by SafetyNet API.
// Updating the value atomically from another thread to provide a simpler guarantee that the
// value is not lost after posting a few tasks.
private final AtomicLong mFirstSafetyNetResponseTimeMicros = new AtomicLong();
public LegacyTabStartupMetricsTracker(
long activityId, ObservableSupplier<TabModelSelector> tabModelSelectorSupplier) {
mActivityId = activityId;
mActivityStartTimeMs = SystemClock.uptimeMillis();
TraceEvent.startupActivityStart(mActivityId, mActivityStartTimeMs);
tabModelSelectorSupplier.addObserver(this::registerObservers);
SafeBrowsingApiBridge.setOneTimeSafetyNetApiUrlCheckObserver(
this::updateSafetyNetCheckTime);
}
private void updateSafetyNetCheckTime(long urlCheckTimeDeltaMicros) {
mFirstSafetyNetResponseTimeMicros.compareAndSet(0, urlCheckTimeDeltaMicros);
}
/**
* Choose the UMA histogram to record later. The {@link ActivityType} parameter indicates the
* kind of startup scenario to track. Only two scenarios are supported.
*
* @param activityType Either TABBED or WEB_APK.
*/
public void setHistogramSuffix(@ActivityType int activityType) {
mHistogramSuffix = activityType;
mShouldTrackStartupMetrics = true;
}
private void registerObservers(TabModelSelector tabModelSelector) {
if (!mShouldTrackStartupMetrics) return;
mTabModelSelectorTabObserver =
new TabModelSelectorTabObserver(tabModelSelector) {
private boolean mIsFirstPageLoadStart = true;
@Override
public void onPageLoadStarted(Tab tab, GURL url) {
// Discard startup navigation measurements when the user interfered and
// started the 2nd navigation (in activity lifetime) in parallel.
if (mIsFirstPageLoadStart) {
mIsFirstPageLoadStart = false;
} else {
mShouldTrackStartupMetrics = false;
}
}
@Override
public void onDidFinishNavigationInPrimaryMainFrame(
Tab tab, NavigationHandle navigation) {
boolean isTrackedPage =
navigation.hasCommitted()
&& !navigation.isErrorPage()
&& !navigation.isSameDocument()
&& UrlUtilities.isHttpOrHttps(navigation.getUrl());
registerFinishNavigation(isTrackedPage);
}
};
mPageLoadMetricsObserver = new PageLoadMetricsObserverImpl();
PageLoadMetrics.addObserver(mPageLoadMetricsObserver, false);
UmaUtils.setObserver(this::registerHasComeToForegroundWithNative);
}
/**
* Registers the fact that UmaUtils#hasComeToForeground() has just become true for the first
* time.
*/
private void registerHasComeToForegroundWithNative() {
// Record cases where first navigation commit and/or StartupPaintPreview's first
// paint happened pre-foregrounding.
if (mRegisteredFirstCommitPreForeground) {
RecordHistogram.recordBooleanHistogram(
FIRST_COMMIT_OCCURRED_PRE_FOREGROUND_HISTOGRAM, true);
}
if (mRegisteredFirstPaintPreForeground) {
RecordHistogram.recordBooleanHistogram(
FIRST_PAINT_OCCURRED_PRE_FOREGROUND_HISTOGRAM, true);
}
RecordHistogram.recordMediumTimesHistogram(
"Startup.Android.Cold.TimeToForegroundSessionStart",
SystemClock.uptimeMillis() - mActivityStartTimeMs);
UmaUtils.removeObserver();
}
/**
* Register an observer to be notified on the first paint of a paint preview if present.
* @param startupPaintPreviewHelper the helper to register the observer to.
*/
public void registerPaintPreviewObserver(StartupPaintPreviewHelper startupPaintPreviewHelper) {
startupPaintPreviewHelper.addMetricsObserver(
new PaintPreviewMetricsObserver() {
@Override
public void onFirstPaint(long durationMs) {
RecordHistogram.recordBooleanHistogram(
FIRST_PAINT_OCCURRED_PRE_FOREGROUND_HISTOGRAM, false);
recordFirstVisibleContent(durationMs);
recordFirstVisibleContent2(durationMs);
recordVisibleContent(durationMs);
}
@Override
public void onUnrecordedFirstPaint() {
// The first paint not being recorded means that either (1) the browser is
// not marked as being in the foreground or (2) it has been backgrounded.
// Update |mRegisteredFirstPaintPreForeground| if appropriate.
if (!UmaUtils.hasComeToForegroundWithNative()
&& !UmaUtils.hasComeToBackgroundWithNative()) {
mRegisteredFirstPaintPreForeground = true;
}
}
});
}
/**
* Cancels tracking the startup metrics.
* Must only be called on the UI thread.
*/
public void cancelTrackingStartupMetrics() {
if (!mShouldTrackStartupMetrics) return;
// Ensure we haven't tried to record metrics already.
assert mFirstCommitTimeMs == 0;
mShouldTrackStartupMetrics = false;
}
/**
* TODO(crbug.com/40944523): This is exposed in order to investigate whether back press will
* interrupt the recording of first visible content related histograms. Remove this once a
* definitive conclusion is reached.
*
* @return Whether first visible content related histogram is recorded.
*/
public boolean isFirstVisibleContentRecorded() {
return mFirstVisibleContent2Recorded;
}
public void onBackPressed() {
mBackPressOccurred = true;
}
public void destroy() {
mShouldTrackStartupMetrics = false;
clearNavigationObservers();
UmaUtils.removeObserver();
}
private void clearNavigationObservers() {
if (mTabModelSelectorTabObserver != null) {
mTabModelSelectorTabObserver.destroy();
mTabModelSelectorTabObserver = null;
}
if (mPageLoadMetricsObserver != null) {
PageLoadMetrics.removeObserver(mPageLoadMetricsObserver);
mPageLoadMetricsObserver = null;
}
}
/**
* Registers the fact that a navigation has finished. Based on this fact, may discard recording
* histograms later.
*/
private void registerFinishNavigation(boolean isTrackedPage) {
if (!mShouldTrackStartupMetrics) return;
if (isTrackedPage
&& UmaUtils.hasComeToForegroundWithNative()
&& !UmaUtils.hasComeToBackgroundWithNative()) {
mFirstCommitTimeMs = SystemClock.uptimeMillis() - mActivityStartTimeMs;
RecordHistogram.recordMediumTimesHistogram(
"Startup.Android.Cold.TimeToFirstNavigationCommit"
+ activityTypeToSuffix(mHistogramSuffix),
mFirstCommitTimeMs);
if (mHistogramSuffix == ActivityType.TABBED) {
recordFirstVisibleContent(mFirstCommitTimeMs);
recordFirstSafeBrowsingResponseTime();
}
RecordHistogram.recordBooleanHistogram(
FIRST_COMMIT_OCCURRED_PRE_FOREGROUND_HISTOGRAM, false);
} else if (isTrackedPage
&& !UmaUtils.hasComeToForegroundWithNative()
&& !UmaUtils.hasComeToBackgroundWithNative()) {
mRegisteredFirstCommitPreForeground = true;
}
if (mHistogramSuffix == ActivityType.TABBED
&& isTrackedPage
&& SimpleStartupForegroundSessionDetector.runningCleanForegroundSession()) {
mFirstCommitTimeMs = SystemClock.uptimeMillis() - mActivityStartTimeMs;
RecordHistogram.recordMediumTimesHistogram(
"Startup.Android.Cold.TimeToFirstNavigationCommit2.Tabbed", mFirstCommitTimeMs);
recordFirstVisibleContent2(mFirstCommitTimeMs);
}
mShouldTrackStartupMetrics = false;
}
private String activityTypeToSuffix(@ActivityType int type) {
if (type == ActivityType.TABBED) return ".Tabbed";
assert type == ActivityType.WEB_APK;
return ".WebApk";
}
private void recordFirstSafeBrowsingResponseTime() {
long safetyNetDeltaMicros = mFirstSafetyNetResponseTimeMicros.getAndSet(0);
if (safetyNetDeltaMicros != 0) {
RecordHistogram.recordMediumTimesHistogram(
"Startup.Android.Cold.FirstSafeBrowsingResponseTime.Tabbed",
safetyNetDeltaMicros / 1000);
}
}
/**
* Record the First Contentful Paint time.
*
* @param firstContentfulPaintMs timestamp in uptime millis.
*/
private void recordFirstContentfulPaint(long firstContentfulPaintMs) {
// First commit time histogram should be recorded before this one. We should discard a
// record if the first commit time wasn't recorded.
if (mFirstCommitTimeMs == 0) return;
if (UmaUtils.hasComeToForegroundWithNative() && !UmaUtils.hasComeToBackgroundWithNative()) {
long durationMs = firstContentfulPaintMs - mActivityStartTimeMs;
RecordHistogram.recordMediumTimesHistogram(
"Startup.Android.Cold.TimeToFirstContentfulPaint"
+ activityTypeToSuffix(mHistogramSuffix),
durationMs);
if (mHistogramSuffix == ActivityType.TABBED) {
recordVisibleContent(durationMs);
}
}
// This is the last navigation-related event we track, so clean up related state.
mShouldTrackStartupMetrics = false;
clearNavigationObservers();
}
/**
* Records the legacy version of the time to first visible content.
*
* This metric acts as the Clank cold start guardian metric.
*
* Reports the minimum value of Startup.Android.Cold.TimeToFirstNavigationCommit.Tabbed and
* Browser.PaintPreview.TabbedPlayer.TimeToFirstBitmap.
*
* @param durationMs duration in millis.
*/
private void recordFirstVisibleContent(long durationMs) {
if (mFirstVisibleContentRecorded) return;
mFirstVisibleContentRecorded = true;
RecordHistogram.recordMediumTimesHistogram(
"Startup.Android.Cold.TimeToFirstVisibleContent", durationMs);
}
/**
* Records the time to first visible content.
*
* This metric aims to become the new the Clank cold start guardian metric.
*
* Reports the minimum value of Startup.Android.Cold.TimeToFirstNavigationCommit2.Tabbed and
* Browser.PaintPreview.TabbedPlayer.TimeToFirstBitmap.
*
* @param durationMs duration in millis.
*/
private void recordFirstVisibleContent2(long durationMs) {
if (mFirstVisibleContent2Recorded) return;
mFirstVisibleContent2Recorded = true;
RecordHistogram.recordMediumTimesHistogram(
"Startup.Android.Cold.TimeToFirstVisibleContent2", durationMs);
TraceEvent.startupTimeToFirstVisibleContent2(mActivityId, mActivityStartTimeMs, durationMs);
if (mBackPressOccurred) {
RecordUserAction.record("FirstVisibleContentAfterBackPress");
}
}
/**
* Record the first Visible Content time.
* This metric reports the minimum value of
* Startup.Android.Cold.TimeToFirstContentfulPaint.Tabbed and
* Browser.PaintPreview.TabbedPlayer.TimeToFirstBitmap.
*
* @param durationMs duration in millis.
*/
private void recordVisibleContent(long durationMs) {
if (mVisibleContentRecorded) return;
mVisibleContentRecorded = true;
RecordHistogram.recordMediumTimesHistogram(
"Startup.Android.Cold.TimeToVisibleContent", durationMs);
}
}
Codebase Browser
chromium