[smart-charging] Collect last charge features

Adds code to collect last charge related features.

Bug: 1028853
Change-Id: I2b152139db0777acbd40534128ed8c92004799b5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1994035
Commit-Queue: Thanh Nguyen <thanhdng@chromium.org>
Reviewed-by: Jia Meng <jiameng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#731862}

chrome/browser/chromeos/power/smart_charging/smart_charging_manager.h

@@ -5,6 +5,7 @@
 #ifndef CHROME_BROWSER_CHROMEOS_POWER_SMART_CHARGING_SMART_CHARGING_MANAGER_H_
 #define CHROME_BROWSER_CHROMEOS_POWER_SMART_CHARGING_SMART_CHARGING_MANAGER_H_
 
+#include "base/files/file_path.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
@@ -16,6 +17,8 @@
 #include "chrome/browser/chromeos/power/smart_charging/smart_charging_ukm_logger.h"
 #include "chrome/browser/chromeos/power/smart_charging/user_charging_event.pb.h"
 #include "chromeos/dbus/power/power_manager_client.h"
+#include "components/session_manager/core/session_manager.h"
+#include "components/session_manager/core/session_manager_observer.h"
 #include "mojo/public/cpp/bindings/receiver.h"
 #include "services/viz/public/mojom/compositing/video_detector_observer.mojom.h"
 #include "ui/base/user_activity/user_activity_detector.h"
@@ -27,16 +30,21 @@ namespace ml {
 class RecentEventsCounter;
 }  // namespace ml
 
+using PastEvent = PastChargingEvents::Event;
+using EventReason = UserChargingEvent::Event::Reason;
+
 // SmartChargingManager logs battery percentage and other features related to
 // user charging events. It is currently used to log data and will be
 // extended to do inference in the future.
 class SmartChargingManager : public ui::UserActivityObserver,
                              public PowerManagerClient::Observer,
-                             public viz::mojom::VideoDetectorObserver {
+                             public viz::mojom::VideoDetectorObserver,
+                             public session_manager::SessionManagerObserver {
  public:
   SmartChargingManager(
       ui::UserActivityDetector* detector,
       mojo::PendingReceiver<viz::mojom::VideoDetectorObserver> receiver,
+      session_manager::SessionManager* session_manager,
       std::unique_ptr<base::RepeatingTimer> periodic_timer);
   ~SmartChargingManager() override;
   SmartChargingManager(const SmartChargingManager&) = delete;
@@ -73,6 +81,9 @@ class SmartChargingManager : public ui::UserActivityObserver,
   void OnVideoActivityStarted() override;
   void OnVideoActivityEnded() override;
 
+  // session_manager::SessionManagerObserver overrides:
+  void OnUserSessionStarted(bool is_primary_user) override;
+
  private:
   friend class SmartChargingManagerTest;
 
@@ -80,7 +91,7 @@ class SmartChargingManager : public ui::UserActivityObserver,
   void PopulateUserChargingEventProto(UserChargingEvent* proto);
 
   // Log the event.
-  void LogEvent(const UserChargingEvent::Event::Reason& reason);
+  void LogEvent(const EventReason& reason);
 
   // Called when the periodic timer triggers.
   void OnTimerFired();
@@ -97,16 +108,47 @@ class SmartChargingManager : public ui::UserActivityObserver,
   // minutes).
   base::TimeDelta DurationRecentVideoPlaying();
 
+  // Checks if the file for current user exists, if yes loads from disk.
+  void MaybeLoadFromDisk();
+
+  // Checks if we can create a path on disk to save the data, if yes saves to
+  // disk.
+  void MaybeSaveToDisk();
+
+  // Loads data from disk given a file path.
+  void LoadFromDisk(const base::FilePath& file_path);
+
+  // Saves data to disk given a file path.
+  void SaveToDisk(const base::FilePath& file_path);
+
+  // Calls after SaveToDisk completes.
+  void OnLoadProtoFromDiskComplete(std::unique_ptr<PastChargingEvents> proto);
+
+  // Adds a past events given it's reason to |past_events_|.
+  void AddPastEvent(const EventReason& reason);
+
+  // Updates and deletes events.
+  void UpdatePastEvents();
+
+  // Gets the "plug in" and "unplug" events of the last charge.
+  std::tuple<PastEvent, PastEvent> GetLastChargeEvents();
+
   ScopedObserver<ui::UserActivityDetector, ui::UserActivityObserver>
       user_activity_observer_{this};
 
   ScopedObserver<chromeos::PowerManagerClient,
                  chromeos::PowerManagerClient::Observer>
       power_manager_client_observer_{this};
+  ScopedObserver<session_manager::SessionManager,
+                 session_manager::SessionManagerObserver>
+      session_manager_observer_{this};
 
   // Timer to trigger periodically for logging data.
   const std::unique_ptr<base::RepeatingTimer> periodic_timer_;
 
+  // Checks if data is loaded from disk yet.
+  bool loaded_from_disk_ = false;
+
   // Helper to return TimeSinceBoot.
   ml::BootClock boot_clock_;
   int event_id_ = -1;
@@ -134,6 +176,7 @@ class SmartChargingManager : public ui::UserActivityObserver,
   // TODO(crbug.com/1028853): This is for testing only. Need to remove when ukm
   // logger is available.
   UserChargingEvent user_charging_event_for_test_;
+  std::vector<PastEvent> past_events_;
 
   base::Optional<double> battery_percent_;
   base::Optional<double> screen_brightness_percent_;
@@ -143,6 +186,7 @@ class SmartChargingManager : public ui::UserActivityObserver,
   const std::unique_ptr<SmartChargingUkmLogger> ukm_logger_;
 
   SEQUENCE_CHECKER(sequence_checker_);
+  scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
   base::WeakPtrFactory<SmartChargingManager> weak_ptr_factory_{this};
 };
 

chrome/browser/chromeos/power/smart_charging/user_charging_event.proto

@@ -117,3 +117,21 @@ message UserChargingEvent {
   optional Features features = 1;
   optional Event event = 2;
 }
+
+// PastChargingEvents contain a list of events that have information about "past
+// charging events". It will only store the plug/unplug pair of the last charge
+// and a recent plug/halt event if any.
+message PastChargingEvents {
+  message Event {
+    // Time of the event in minutes since Windows epoch.
+    optional int32 time = 1;
+    // Battery percentage of the device.
+    optional int32 battery_percent = 2;
+    // Timezone of the device.
+    optional int32 timezone = 3;
+    // Reason for the event.
+    optional UserChargingEvent.Event.Reason reason = 4;
+  }
+  // A list containing past charging events.
+  repeated Event events = 1;
+}