src/content/browser/battery_status/battery_status_manager_linux.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/browser/battery_status/battery_status_manager_linux.h"
   6
   7 #include "base/macros.h"
   8 #include "base/threading/thread.h"
   9 #include "base/values.h"
  10 #include "content/browser/battery_status/battery_status_manager.h"
  11 #include "content/public/browser/browser_thread.h"
  12 #include "dbus/bus.h"
  13 #include "dbus/message.h"
  14 #include "dbus/object_path.h"
  15 #include "dbus/object_proxy.h"
  16 #include "dbus/property.h"
  17 #include "dbus/values_util.h"
  18
  19 namespace content {
  20
  21 namespace {
  22
  23 const char kUPowerServiceName[] = "org.freedesktop.UPower";
  24 const char kUPowerDeviceName[] = "org.freedesktop.UPower.Device";
  25 const char kUPowerPath[] = "/org/freedesktop/UPower";
  26 const char kUPowerDeviceSignalChanged[] = "Changed";
  27 const char kUPowerEnumerateDevices[] = "EnumerateDevices";
  28 const char kBatteryNotifierThreadName[] = "BatteryStatusNotifier";
  29
  30 // UPowerDeviceType reflects the possible UPower.Device.Type values,
  31 // see upower.freedesktop.org/docs/Device.html#Device:Type.
  32 enum UPowerDeviceType {
  33   UPOWER_DEVICE_TYPE_UNKNOWN = 0,
  34   UPOWER_DEVICE_TYPE_LINE_POWER = 1,
  35   UPOWER_DEVICE_TYPE_BATTERY = 2,
  36   UPOWER_DEVICE_TYPE_UPS = 3,
  37   UPOWER_DEVICE_TYPE_MONITOR = 4,
  38   UPOWER_DEVICE_TYPE_MOUSE = 5,
  39   UPOWER_DEVICE_TYPE_KEYBOARD = 6,
  40   UPOWER_DEVICE_TYPE_PDA = 7,
  41   UPOWER_DEVICE_TYPE_PHONE = 8,
  42 };
  43
  44 typedef std::vector<dbus::ObjectPath> PathsVector;
  45
  46 double GetPropertyAsDouble(const base::DictionaryValue& dictionary,
  47                            const std::string& property_name,
  48                            double default_value) {
  49   double value = default_value;
  50   return dictionary.GetDouble(property_name, &value) ? value : default_value;
  51 }
  52
  53 bool GetPropertyAsBoolean(const base::DictionaryValue& dictionary,
  54                           const std::string& property_name,
  55                           bool default_value) {
  56   bool value = default_value;
  57   return dictionary.GetBoolean(property_name, &value) ? value : default_value;
  58 }
  59
  60 scoped_ptr<base::DictionaryValue> GetPropertiesAsDictionary(
  61     dbus::ObjectProxy* proxy) {
  62   dbus::MethodCall method_call(dbus::kPropertiesInterface,
  63                                dbus::kPropertiesGetAll);
  64   dbus::MessageWriter builder(&method_call);
  65   builder.AppendString(kUPowerDeviceName);
  66
  67   scoped_ptr<dbus::Response> response(
  68       proxy->CallMethodAndBlock(&method_call,
  69                                 dbus::ObjectProxy::TIMEOUT_USE_DEFAULT));
  70   if (response) {
  71     dbus::MessageReader reader(response.get());
  72     scoped_ptr<base::Value> value(dbus::PopDataAsValue(&reader));
  73     base::DictionaryValue* dictionary_value = NULL;
  74     if (value && value->GetAsDictionary(&dictionary_value)) {
  75       ignore_result(value.release());
  76       return scoped_ptr<base::DictionaryValue>(dictionary_value);
  77     }
  78   }
  79   return scoped_ptr<base::DictionaryValue>();
  80 }
  81
  82 scoped_ptr<PathsVector> GetPowerSourcesPaths(dbus::ObjectProxy* proxy) {
  83   scoped_ptr<PathsVector> paths(new PathsVector());
  84   if (!proxy)
  85     return paths.Pass();
  86
  87   dbus::MethodCall method_call(kUPowerServiceName, kUPowerEnumerateDevices);
  88   scoped_ptr<dbus::Response> response(
  89       proxy->CallMethodAndBlock(&method_call,
  90                                 dbus::ObjectProxy::TIMEOUT_USE_DEFAULT));
  91
  92   if (response) {
  93     dbus::MessageReader reader(response.get());
  94     reader.PopArrayOfObjectPaths(paths.get());
  95   }
  96   return paths.Pass();;
  97 }
  98
  99 // Class that represents a dedicated thread which communicates with DBus to
 100 // obtain battery information and receives battery change notifications.
 101 class BatteryStatusNotificationThread : public base::Thread {
 102  public:
 103   BatteryStatusNotificationThread(
 104       const BatteryStatusService::BatteryUpdateCallback& callback)
 105       : base::Thread(kBatteryNotifierThreadName),
 106         callback_(callback),
 107         battery_proxy_(NULL) {}
 108
 109   virtual ~BatteryStatusNotificationThread() {
 110     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 111
 112     // Make sure to shutdown the dbus connection if it is still open in the very
 113     // end. It needs to happen on the BatteryStatusNotificationThread.
 114     message_loop()->PostTask(
 115         FROM_HERE,
 116         base::Bind(&BatteryStatusNotificationThread::ShutdownDBusConnection,
 117                    base::Unretained(this)));
 118
 119     // Drain the message queue of the BatteryStatusNotificationThread and stop.
 120     Stop();
 121   }
 122
 123   void StartListening() {
 124     DCHECK(OnWatcherThread());
 125
 126     if (system_bus_)
 127       return;
 128
 129     InitDBus();
 130     dbus::ObjectProxy* power_proxy =
 131         system_bus_->GetObjectProxy(kUPowerServiceName,
 132                                     dbus::ObjectPath(kUPowerPath));
 133     scoped_ptr<PathsVector> device_paths = GetPowerSourcesPaths(power_proxy);
 134
 135     for (size_t i = 0; i < device_paths->size(); ++i) {
 136       const dbus::ObjectPath& device_path = device_paths->at(i);
 137       dbus::ObjectProxy* device_proxy = system_bus_->GetObjectProxy(
 138           kUPowerServiceName, device_path);
 139       scoped_ptr<base::DictionaryValue> dictionary =
 140           GetPropertiesAsDictionary(device_proxy);
 141
 142       if (!dictionary)
 143         continue;
 144
 145       bool is_present = GetPropertyAsBoolean(*dictionary, "IsPresent", false);
 146       uint32 type = static_cast<uint32>(
 147           GetPropertyAsDouble(*dictionary, "Type", UPOWER_DEVICE_TYPE_UNKNOWN));
 148
 149       if (!is_present || type != UPOWER_DEVICE_TYPE_BATTERY) {
 150         system_bus_->RemoveObjectProxy(kUPowerServiceName,
 151                                        device_path,
 152                                        base::Bind(&base::DoNothing));
 153         continue;
 154       }
 155
 156       if (battery_proxy_) {
 157         // TODO(timvolodine): add support for multiple batteries. Currently we
 158         // only collect information from the first battery we encounter
 159         // (crbug.com/400780).
 160         // TODO(timvolodine): add UMA logging for this case.
 161         LOG(WARNING) << "multiple batteries found, "
 162                      << "using status data of the first battery only.";
 163       } else {
 164         battery_proxy_ = device_proxy;
 165       }
 166     }
 167
 168     if (!battery_proxy_) {
 169       callback_.Run(blink::WebBatteryStatus());
 170       return;
 171     }
 172
 173     battery_proxy_->ConnectToSignal(
 174         kUPowerDeviceName,
 175         kUPowerDeviceSignalChanged,
 176         base::Bind(&BatteryStatusNotificationThread::BatteryChanged,
 177                    base::Unretained(this)),
 178         base::Bind(&BatteryStatusNotificationThread::OnSignalConnected,
 179                    base::Unretained(this)));
 180   }
 181
 182   void StopListening() {
 183     DCHECK(OnWatcherThread());
 184     ShutdownDBusConnection();
 185   }
 186
 187  private:
 188   bool OnWatcherThread() {
 189     return task_runner()->BelongsToCurrentThread();
 190   }
 191
 192   void InitDBus() {
 193     DCHECK(OnWatcherThread());
 194
 195     dbus::Bus::Options options;
 196     options.bus_type = dbus::Bus::SYSTEM;
 197     options.connection_type = dbus::Bus::PRIVATE;
 198     system_bus_ = new dbus::Bus(options);
 199   }
 200
 201   void ShutdownDBusConnection() {
 202     DCHECK(OnWatcherThread());
 203
 204     if (!system_bus_)
 205       return;
 206
 207     // Shutdown DBus connection later because there may be pending tasks on
 208     // this thread.
 209     message_loop()->PostTask(FROM_HERE,
 210                              base::Bind(&dbus::Bus::ShutdownAndBlock,
 211                                         system_bus_));
 212     system_bus_ = NULL;
 213     battery_proxy_ = NULL;
 214   }
 215
 216   void OnSignalConnected(const std::string& interface_name,
 217                          const std::string& signal_name,
 218                          bool success) {
 219     DCHECK(OnWatcherThread());
 220
 221     if (interface_name != kUPowerDeviceName ||
 222         signal_name != kUPowerDeviceSignalChanged) {
 223       return;
 224     }
 225
 226     if (!system_bus_)
 227       return;
 228
 229     if (success) {
 230       BatteryChanged(NULL);
 231     } else {
 232       // Failed to register for "Changed" signal, execute callback with the
 233       // default values.
 234       callback_.Run(blink::WebBatteryStatus());
 235     }
 236   }
 237
 238   void BatteryChanged(dbus::Signal* signal /* unsused */) {
 239     DCHECK(OnWatcherThread());
 240
 241     if (!system_bus_)
 242       return;
 243
 244     scoped_ptr<base::DictionaryValue> dictionary =
 245         GetPropertiesAsDictionary(battery_proxy_);
 246     if (dictionary)
 247       callback_.Run(ComputeWebBatteryStatus(*dictionary));
 248     else
 249       callback_.Run(blink::WebBatteryStatus());
 250   }
 251
 252   BatteryStatusService::BatteryUpdateCallback callback_;
 253   scoped_refptr<dbus::Bus> system_bus_;
 254   dbus::ObjectProxy* battery_proxy_;  // owned by the bus
 255
 256   DISALLOW_COPY_AND_ASSIGN(BatteryStatusNotificationThread);
 257 };
 258
 259 // Runs on IO thread and creates a notification thread and delegates Start/Stop
 260 // calls to it.
 261 class BatteryStatusManagerLinux : public BatteryStatusManager {
 262  public:
 263   explicit BatteryStatusManagerLinux(
 264       const BatteryStatusService::BatteryUpdateCallback& callback)
 265       : callback_(callback) {}
 266
 267   virtual ~BatteryStatusManagerLinux() {}
 268
 269  private:
 270   // BatteryStatusManager:
 271   virtual bool StartListeningBatteryChange() OVERRIDE {
 272     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 273
 274     if (!StartNotifierThreadIfNecessary())
 275       return false;
 276
 277     notifier_thread_->message_loop()->PostTask(
 278         FROM_HERE,
 279         base::Bind(&BatteryStatusNotificationThread::StartListening,
 280                    base::Unretained(notifier_thread_.get())));
 281     return true;
 282   }
 283
 284   virtual void StopListeningBatteryChange() OVERRIDE {
 285     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 286
 287     if (!notifier_thread_)
 288       return;
 289
 290     notifier_thread_->message_loop()->PostTask(
 291         FROM_HERE,
 292         base::Bind(&BatteryStatusNotificationThread::StopListening,
 293                    base::Unretained(notifier_thread_.get())));
 294   }
 295
 296   // Starts the notifier thread if not already started and returns true on
 297   // success.
 298   bool StartNotifierThreadIfNecessary() {
 299     if (notifier_thread_)
 300       return true;
 301
 302     base::Thread::Options thread_options(base::MessageLoop::TYPE_IO, 0);
 303     notifier_thread_.reset(new BatteryStatusNotificationThread(callback_));
 304     if (!notifier_thread_->StartWithOptions(thread_options)) {
 305       notifier_thread_.reset();
 306       LOG(ERROR) << "Could not start the " << kBatteryNotifierThreadName
 307                  << " thread";
 308       return false;
 309     }
 310     return true;
 311   }
 312
 313   BatteryStatusService::BatteryUpdateCallback callback_;
 314   scoped_ptr<BatteryStatusNotificationThread> notifier_thread_;
 315
 316   DISALLOW_COPY_AND_ASSIGN(BatteryStatusManagerLinux);
 317 };
 318
 319 }  // namespace
 320
 321 blink::WebBatteryStatus ComputeWebBatteryStatus(
 322     const base::DictionaryValue& dictionary) {
 323   blink::WebBatteryStatus status;
 324   if (!dictionary.HasKey("State"))
 325     return status;
 326
 327   uint32 state = static_cast<uint32>(
 328       GetPropertyAsDouble(dictionary, "State", UPOWER_DEVICE_STATE_UNKNOWN));
 329   status.charging = state != UPOWER_DEVICE_STATE_DISCHARGING &&
 330                     state != UPOWER_DEVICE_STATE_EMPTY;
 331   double percentage = GetPropertyAsDouble(dictionary, "Percentage", 100);
 332   // Convert percentage to a value between 0 and 1 with 2 digits of precision.
 333   // This is to bring it in line with other platforms like Mac and Android where
 334   // we report level with 1% granularity. It also serves the purpose of reducing
 335   // the possibility of fingerprinting and triggers less level change events on
 336   // the blink side.
 337   // TODO(timvolodine): consider moving this rounding to the blink side.
 338   status.level = round(percentage) / 100.f;
 339
 340   switch (state) {
 341     case UPOWER_DEVICE_STATE_CHARGING : {
 342       double time_to_full = GetPropertyAsDouble(dictionary, "TimeToFull", 0);
 343       status.chargingTime =
 344           (time_to_full > 0) ? time_to_full
 345                              : std::numeric_limits<double>::infinity();
 346       break;
 347     }
 348     case UPOWER_DEVICE_STATE_DISCHARGING : {
 349       double time_to_empty = GetPropertyAsDouble(dictionary, "TimeToEmpty", 0);
 350       // Set dischargingTime if it's available. Otherwise leave the default
 351       // value which is +infinity.
 352       if (time_to_empty > 0)
 353         status.dischargingTime = time_to_empty;
 354       status.chargingTime = std::numeric_limits<double>::infinity();
 355       break;
 356     }
 357     case UPOWER_DEVICE_STATE_FULL : {
 358       break;
 359     }
 360     default: {
 361       status.chargingTime = std::numeric_limits<double>::infinity();
 362     }
 363   }
 364   return status;
 365 }
 366
 367 // static
 368 scoped_ptr<BatteryStatusManager> BatteryStatusManager::Create(
 369     const BatteryStatusService::BatteryUpdateCallback& callback) {
 370   return scoped_ptr<BatteryStatusManager>(
 371       new BatteryStatusManagerLinux(callback));
 372 }
 373
 374 }  // namespace content