Fix #8274: Add support for the daily browser session time P3A metric (#…

…8730)

App/iOS/Delegates/AppState.swift

@@ -33,6 +33,7 @@ public class AppState {
  public let profile: Profile
  public let rewards: Brave.BraveRewards
  public let newsFeedDataSource: FeedDataSource
+ public let uptimeMonitor = UptimeMonitor()
  private var didBecomeActive = false
 
  public var state: State = .launching(options: [:], active: false) {

App/iOS/Delegates/SceneDelegate.swift

@@ -218,6 +218,7 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
 
  Preferences.AppState.backgroundedCleanly.value = false
  AppState.shared.profile.reopen()
+ AppState.shared.uptimeMonitor.beginMonitoring()
 
  appDelegate.receivedURLs = nil
  UIApplication.shared.applicationIconBadgeNumber = 0
@@ -248,6 +249,7 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
  func sceneWillResignActive(_ scene: UIScene) {
  Preferences.AppState.backgroundedCleanly.value = true
  scene.userActivity?.resignCurrent()
+ AppState.shared.uptimeMonitor.pauseMonitoring()
  }
 
  func sceneWillEnterForeground(_ scene: UIScene) {

Sources/Growth/GrowthPreferences.swift

@@ -46,4 +46,9 @@ extension Preferences {
  /// The date when the rating card in news feed is shown
  public static let newsCardShownDate = Option<Date?>(key: "review.news-card", default: nil)
  }
+
+ final class UptimeMonitor {
+ static let startTime: Option<Date?> = .init(key: "uptime-monitor-start-time", default: nil)
+ static let uptimeSum: Option<TimeInterval> = .init(key: "uptime-monitor-uptime-sum", default: 0)
+ }
 }

Sources/Growth/UptimeMonitor.swift

@@ -0,0 +1,92 @@
+// Copyright 2024 The Brave Authors. All rights reserved.
+// 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 https://mozilla.org/MPL/2.0/.
+
+import Foundation
+import Preferences
+
+/// Monitors how long the browser is foregrounded to answer the `Brave.Uptime.BrowserOpenTime` P3A question
+public class UptimeMonitor {
+ private var timer: Timer?
+
+ private(set) static var usageInterval: TimeInterval = 15
+ private(set) static var now: () -> Date = { .now }
+ private(set) static var calendar: Calendar = .current
+
+ public init() {
+ if Preferences.UptimeMonitor.startTime.value == nil {
+ // If today is the first time monitoring uptime, set the frame start time to now.
+ resetPrefs()
+ }
+ recordP3A()
+ }
+
+ deinit {
+ timer?.invalidate()
+ }
+
+ // For testing
+ var didRecordP3A: ((_ durationInMinutes: Int) -> Void)?
+
+ public var isMonitoring: Bool {
+ timer != nil
+ }
+
+ /// Begins a timer to monitor uptime
+ public func beginMonitoring() {
+ if isMonitoring {
+ return
+ }
+ timer = Timer.scheduledTimer(withTimeInterval: Self.usageInterval, repeats: true, block: { [weak self] _ in
+ guard let self else { return }
+ Preferences.UptimeMonitor.uptimeSum.value += Self.usageInterval
+ self.recordP3A()
+ })
+ }
+ /// Pauses the timer to monitor uptime
+ public func pauseMonitoring() {
+ timer?.invalidate()
+ timer = nil
+ }
+
+ private func recordP3A() {
+ guard let startTime = Preferences.UptimeMonitor.startTime.value,
+ !Self.calendar.isDate(startTime, inSameDayAs: Self.now()) else {
+ // Do not report, since 1 day has not passed.
+ return
+ }
+ let buckets: [Bucket] = [
+ .r(0...30),
+ .r(31...60),
+ .r(61...120), // 1-2 hours
+ .r(121...180), // 2-3 hours
+ .r(181...300), // 3-5 hours
+ .r(301...420), // 5-7 hours
+ .r(421...600), // 7-10 hours
+ .r(601...) // 10+ hours
+ ]
+ let durationInMinutes = Int(Preferences.UptimeMonitor.uptimeSum.value / 60.0)
+ UmaHistogramRecordValueToBucket("Brave.Uptime.BrowserOpenMinutes", buckets: buckets, value: durationInMinutes)
+ resetPrefs()
+ didRecordP3A?(durationInMinutes)
+ }
+
+ private func resetPrefs() {
+ Preferences.UptimeMonitor.startTime.value = Self.now()
+ Preferences.UptimeMonitor.uptimeSum.value = 0
+ }
+
+ static func setUsageIntervalForTesting(_ usageInterval: TimeInterval) {
+ Self.usageInterval = usageInterval
+ }
+
+ static func setNowForTesting(_ now: @escaping () -> Date) {
+ Self.now = now
+ }
+
+ static func setCalendarForTesting(_ calendar: Calendar) {
+ Self.calendar = calendar
+ }
+}
+

Tests/GrowthTests/UptimeMonitorTests.swift

@@ -0,0 +1,76 @@
+// Copyright 2024 The Brave Authors. All rights reserved.
+// 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 https://mozilla.org/MPL/2.0/.
+
+import Foundation
+import XCTest
+import Preferences
+@testable import Growth
+
+class UptimeMonitorTests: XCTestCase {
+
+ // How much a single second is actually accounted for during the test
+ static let testSecond: TimeInterval = 0.01
+
+ override func setUp() {
+ super.setUp()
+
+ Preferences.UptimeMonitor.startTime.reset()
+ Preferences.UptimeMonitor.uptimeSum.reset()
+
+ var testCalendar = Calendar(identifier: .gregorian)
+ testCalendar.timeZone = .init(abbreviation: "GMT")!
+ testCalendar.locale = .init(identifier: "en_US_POSIX")
+ UptimeMonitor.setCalendarForTesting(testCalendar)
+ UptimeMonitor.setNowForTesting({ .now })
+ UptimeMonitor.setUsageIntervalForTesting(Self.testSecond)
+ }
+
+ func testNoStartTimeInit() {
+ XCTAssertNil(Preferences.UptimeMonitor.startTime.value)
+ let um = UptimeMonitor()
+ XCTAssertNotNil(Preferences.UptimeMonitor.startTime.value)
+ XCTAssertFalse(um.isMonitoring)
+ }
+
+ func testRecordAfterDay() {
+ let um = UptimeMonitor()
+ let e = expectation(description: "recorded")
+ let now = Date()
+ UptimeMonitor.setNowForTesting({ now })
+ Preferences.UptimeMonitor.startTime.value = .now.addingTimeInterval(-60*60*24)
+ Preferences.UptimeMonitor.uptimeSum.value = 60
+ um.didRecordP3A = { minutes in
+ XCTAssertEqual(minutes, 1)
+ e.fulfill()
+ }
+ um.beginMonitoring()
+ wait(for: [e], timeout: Self.testSecond * 2)
+ um.pauseMonitoring()
+
+ // Ensure prefs are reset
+ XCTAssertEqual(Preferences.UptimeMonitor.startTime.value, now)
+ XCTAssertEqual(Preferences.UptimeMonitor.uptimeSum.value, 0)
+ }
+
+ func testNoRecordBeforeOneDay() {
+ let um = UptimeMonitor()
+ let now = Date()
+ UptimeMonitor.setNowForTesting({ now })
+ let e = expectation(description: "not-recorded")
+ e.isInverted = true
+ Preferences.UptimeMonitor.startTime.value = now
+ Preferences.UptimeMonitor.uptimeSum.value = 60
+ um.didRecordP3A = { _ in
+ XCTFail("Should not record any data before a day has passed")
+ }
+ um.beginMonitoring()
+ wait(for: [e], timeout: Self.testSecond * 2)
+ um.pauseMonitoring()
+
+ // Ensure prefs are not reset
+ XCTAssertEqual(Preferences.UptimeMonitor.startTime.value, now)
+ XCTAssertNotEqual(Preferences.UptimeMonitor.uptimeSum.value, 0)
+ }
+}