hal/linux/UPowerClient.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "Hal.h"
   7 #include "HalLog.h"
   8 #include <dbus/dbus-glib.h>
   9 #include <dbus/dbus-glib-lowlevel.h>
  10 #include <mozilla/Attributes.h>
  11 #include <mozilla/dom/battery/Constants.h>
  12 #include "nsAutoRef.h"
  13 #include <cmath>
  14
  15 /*
  16  * Helper that manages the destruction of glib objects as soon as they leave
  17  * the current scope.
  18  *
  19  * We are specializing nsAutoRef class.
  20  */
  21
  22 template <>
  23 class nsAutoRefTraits<GHashTable> : public nsPointerRefTraits<GHashTable> {
  24  public:
  25   static void Release(GHashTable* ptr) { g_hash_table_unref(ptr); }
  26 };
  27
  28 using namespace mozilla::dom::battery;
  29
  30 namespace mozilla {
  31 namespace hal_impl {
  32
  33 /**
  34  * This is the declaration of UPowerClient class. This class is listening and
  35  * communicating to upower daemon through DBus.
  36  * There is no header file because this class shouldn't be public.
  37  */
  38 class UPowerClient {
  39  public:
  40   static UPowerClient* GetInstance();
  41
  42   void BeginListening();
  43   void StopListening();
  44
  45   double GetLevel();
  46   bool IsCharging();
  47   double GetRemainingTime();
  48
  49   ~UPowerClient();
  50
  51  private:
  52   UPowerClient();
  53
  54   enum States {
  55     eState_Unknown = 0,
  56     eState_Charging,
  57     eState_Discharging,
  58     eState_Empty,
  59     eState_FullyCharged,
  60     eState_PendingCharge,
  61     eState_PendingDischarge
  62   };
  63
  64   /**
  65    * Update the currently tracked device.
  66    * @return whether everything went ok.
  67    */
  68   void UpdateTrackedDeviceSync();
  69
  70   /**
  71    * Returns a hash table with the properties of aDevice.
  72    * Note: the caller has to unref the hash table.
  73    */
  74   GHashTable* GetDevicePropertiesSync(DBusGProxy* aProxy);
  75   void GetDevicePropertiesAsync(DBusGProxy* aProxy);
  76   static void GetDevicePropertiesCallback(DBusGProxy* aProxy,
  77                                           DBusGProxyCall* aCall, void* aData);
  78
  79   /**
  80    * Using the device properties (aHashTable), this method updates the member
  81    * variable storing the values we care about.
  82    */
  83   void UpdateSavedInfo(GHashTable* aHashTable);
  84
  85   /**
  86    * Callback used by 'DeviceChanged' signal.
  87    */
  88   static void DeviceChanged(DBusGProxy* aProxy, const gchar* aObjectPath,
  89                             UPowerClient* aListener);
  90
  91   /**
  92    * Callback used by 'PropertiesChanged' signal.
  93    * This method is called when the the battery level changes.
  94    * (Only with upower >= 0.99)
  95    */
  96   static void PropertiesChanged(DBusGProxy* aProxy, const gchar*, GHashTable*,
  97                                 char**, UPowerClient* aListener);
  98
  99   /**
 100    * Callback called when mDBusConnection gets a signal.
 101    */
 102   static DBusHandlerResult ConnectionSignalFilter(DBusConnection* aConnection,
 103                                                   DBusMessage* aMessage,
 104                                                   void* aData);
 105
 106   // The DBus connection object.
 107   DBusGConnection* mDBusConnection;
 108
 109   // The DBus proxy object to upower.
 110   DBusGProxy* mUPowerProxy;
 111
 112   // The path of the tracked device.
 113   gchar* mTrackedDevice;
 114
 115   // The DBusGProxy for the tracked device.
 116   DBusGProxy* mTrackedDeviceProxy;
 117
 118   double mLevel;
 119   bool mCharging;
 120   double mRemainingTime;
 121
 122   static UPowerClient* sInstance;
 123
 124   static const guint sDeviceTypeBattery = 2;
 125   static const guint64 kUPowerUnknownRemainingTime = 0;
 126 };
 127
 128 /*
 129  * Implementation of mozilla::hal_impl::EnableBatteryNotifications,
 130  *                   mozilla::hal_impl::DisableBatteryNotifications,
 131  *               and mozilla::hal_impl::GetCurrentBatteryInformation.
 132  */
 133
 134 void EnableBatteryNotifications() {
 135   UPowerClient::GetInstance()->BeginListening();
 136 }
 137
 138 void DisableBatteryNotifications() {
 139   UPowerClient::GetInstance()->StopListening();
 140 }
 141
 142 void GetCurrentBatteryInformation(hal::BatteryInformation* aBatteryInfo) {
 143   UPowerClient* upowerClient = UPowerClient::GetInstance();
 144
 145   aBatteryInfo->level() = upowerClient->GetLevel();
 146   aBatteryInfo->charging() = upowerClient->IsCharging();
 147   aBatteryInfo->remainingTime() = upowerClient->GetRemainingTime();
 148 }
 149
 150 /*
 151  * Following is the implementation of UPowerClient.
 152  */
 153
 154 UPowerClient* UPowerClient::sInstance = nullptr;
 155
 156 /* static */
 157 UPowerClient* UPowerClient::GetInstance() {
 158   if (!sInstance) {
 159     sInstance = new UPowerClient();
 160   }
 161
 162   return sInstance;
 163 }
 164
 165 UPowerClient::UPowerClient()
 166     : mDBusConnection(nullptr),
 167       mUPowerProxy(nullptr),
 168       mTrackedDevice(nullptr),
 169       mTrackedDeviceProxy(nullptr),
 170       mLevel(kDefaultLevel),
 171       mCharging(kDefaultCharging),
 172       mRemainingTime(kDefaultRemainingTime) {}
 173
 174 UPowerClient::~UPowerClient() {
 175   NS_ASSERTION(!mDBusConnection && !mUPowerProxy && !mTrackedDevice &&
 176                    !mTrackedDeviceProxy,
 177                "The observers have not been correctly removed! "
 178                "(StopListening should have been called)");
 179 }
 180
 181 void UPowerClient::BeginListening() {
 182   GError* error = nullptr;
 183   mDBusConnection = dbus_g_bus_get(DBUS_BUS_SYSTEM, &error);
 184
 185   if (!mDBusConnection) {
 186     HAL_LOG("Failed to open connection to bus: %s\n", error->message);
 187     g_error_free(error);
 188     return;
 189   }
 190
 191   DBusConnection* dbusConnection =
 192       dbus_g_connection_get_connection(mDBusConnection);
 193
 194   // Make sure we do not exit the entire program if DBus connection get lost.
 195   dbus_connection_set_exit_on_disconnect(dbusConnection, false);
 196
 197   // Listening to signals the DBus connection is going to get so we will know
 198   // when it is lost and we will be able to disconnect cleanly.
 199   dbus_connection_add_filter(dbusConnection, ConnectionSignalFilter, this,
 200                              nullptr);
 201
 202   mUPowerProxy = dbus_g_proxy_new_for_name(
 203       mDBusConnection, "org.freedesktop.UPower", "/org/freedesktop/UPower",
 204       "org.freedesktop.UPower");
 205
 206   UpdateTrackedDeviceSync();
 207
 208   /*
 209    * TODO: we should probably listen to DeviceAdded and DeviceRemoved signals.
 210    * If we do that, we would have to disconnect from those in StopListening.
 211    * It's not yet implemented because it requires testing hot plugging and
 212    * removal of a battery.
 213    */
 214   dbus_g_proxy_add_signal(mUPowerProxy, "DeviceChanged", G_TYPE_STRING,
 215                           G_TYPE_INVALID);
 216   dbus_g_proxy_connect_signal(mUPowerProxy, "DeviceChanged",
 217                               G_CALLBACK(DeviceChanged), this, nullptr);
 218 }
 219
 220 void UPowerClient::StopListening() {
 221   // If mDBusConnection isn't initialized, that means we are not really
 222   // listening.
 223   if (!mDBusConnection) {
 224     return;
 225   }
 226
 227   dbus_connection_remove_filter(
 228       dbus_g_connection_get_connection(mDBusConnection), ConnectionSignalFilter,
 229       this);
 230
 231   dbus_g_proxy_disconnect_signal(mUPowerProxy, "DeviceChanged",
 232                                  G_CALLBACK(DeviceChanged), this);
 233
 234   g_free(mTrackedDevice);
 235   mTrackedDevice = nullptr;
 236
 237   if (mTrackedDeviceProxy) {
 238     dbus_g_proxy_disconnect_signal(mTrackedDeviceProxy, "PropertiesChanged",
 239                                    G_CALLBACK(PropertiesChanged), this);
 240
 241     g_object_unref(mTrackedDeviceProxy);
 242     mTrackedDeviceProxy = nullptr;
 243   }
 244
 245   g_object_unref(mUPowerProxy);
 246   mUPowerProxy = nullptr;
 247
 248   dbus_g_connection_unref(mDBusConnection);
 249   mDBusConnection = nullptr;
 250
 251   // We should now show the default values, not the latest we got.
 252   mLevel = kDefaultLevel;
 253   mCharging = kDefaultCharging;
 254   mRemainingTime = kDefaultRemainingTime;
 255 }
 256
 257 void UPowerClient::UpdateTrackedDeviceSync() {
 258   GType typeGPtrArray =
 259       dbus_g_type_get_collection("GPtrArray", DBUS_TYPE_G_OBJECT_PATH);
 260   GPtrArray* devices = nullptr;
 261   GError* error = nullptr;
 262
 263   // Reset the current tracked device:
 264   g_free(mTrackedDevice);
 265   mTrackedDevice = nullptr;
 266
 267   // Reset the current tracked device proxy:
 268   if (mTrackedDeviceProxy) {
 269     dbus_g_proxy_disconnect_signal(mTrackedDeviceProxy, "PropertiesChanged",
 270                                    G_CALLBACK(PropertiesChanged), this);
 271
 272     g_object_unref(mTrackedDeviceProxy);
 273     mTrackedDeviceProxy = nullptr;
 274   }
 275
 276   // If that fails, that likely means upower isn't installed.
 277   if (!dbus_g_proxy_call(mUPowerProxy, "EnumerateDevices", &error,
 278                          G_TYPE_INVALID, typeGPtrArray, &devices,
 279                          G_TYPE_INVALID)) {
 280     HAL_LOG("Error: %s\n", error->message);
 281     g_error_free(error);
 282     return;
 283   }
 284
 285   /*
 286    * We are looking for the first device that is a battery.
 287    * TODO: we could try to combine more than one battery.
 288    */
 289   for (guint i = 0; i < devices->len; ++i) {
 290     gchar* devicePath = static_cast<gchar*>(g_ptr_array_index(devices, i));
 291
 292     DBusGProxy* proxy = dbus_g_proxy_new_from_proxy(
 293         mUPowerProxy, "org.freedesktop.DBus.Properties", devicePath);
 294
 295     nsAutoRef<GHashTable> hashTable(GetDevicePropertiesSync(proxy));
 296
 297     if (g_value_get_uint(static_cast<const GValue*>(
 298             g_hash_table_lookup(hashTable, "Type"))) == sDeviceTypeBattery) {
 299       UpdateSavedInfo(hashTable);
 300       mTrackedDevice = devicePath;
 301       mTrackedDeviceProxy = proxy;
 302       break;
 303     }
 304
 305     g_object_unref(proxy);
 306     g_free(devicePath);
 307   }
 308
 309   if (mTrackedDeviceProxy) {
 310     dbus_g_proxy_add_signal(
 311         mTrackedDeviceProxy, "PropertiesChanged", G_TYPE_STRING,
 312         dbus_g_type_get_map("GHashTable", G_TYPE_STRING, G_TYPE_VALUE),
 313         G_TYPE_STRV, G_TYPE_INVALID);
 314     dbus_g_proxy_connect_signal(mTrackedDeviceProxy, "PropertiesChanged",
 315                                 G_CALLBACK(PropertiesChanged), this, nullptr);
 316   }
 317
 318   g_ptr_array_free(devices, true);
 319 }
 320
 321 /* static */
 322 void UPowerClient::DeviceChanged(DBusGProxy* aProxy, const gchar* aObjectPath,
 323                                  UPowerClient* aListener) {
 324   if (!aListener->mTrackedDevice) {
 325     return;
 326   }
 327
 328 #if GLIB_MAJOR_VERSION >= 2 && GLIB_MINOR_VERSION >= 16
 329   if (g_strcmp0(aObjectPath, aListener->mTrackedDevice)) {
 330 #else
 331   if (g_ascii_strcasecmp(aObjectPath, aListener->mTrackedDevice)) {
 332 #endif
 333     return;
 334   }
 335
 336   aListener->GetDevicePropertiesAsync(aListener->mTrackedDeviceProxy);
 337 }
 338
 339 /* static */
 340 void UPowerClient::PropertiesChanged(DBusGProxy* aProxy, const gchar*,
 341                                      GHashTable*, char**,
 342                                      UPowerClient* aListener) {
 343   aListener->GetDevicePropertiesAsync(aListener->mTrackedDeviceProxy);
 344 }
 345
 346 /* static */
 347 DBusHandlerResult UPowerClient::ConnectionSignalFilter(
 348     DBusConnection* aConnection, DBusMessage* aMessage, void* aData) {
 349   if (dbus_message_is_signal(aMessage, DBUS_INTERFACE_LOCAL, "Disconnected")) {
 350     static_cast<UPowerClient*>(aData)->StopListening();
 351     // We do not return DBUS_HANDLER_RESULT_HANDLED here because the connection
 352     // might be shared and some other filters might want to do something.
 353   }
 354
 355   return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 356 }
 357
 358 GHashTable* UPowerClient::GetDevicePropertiesSync(DBusGProxy* aProxy) {
 359   GError* error = nullptr;
 360   GHashTable* hashTable = nullptr;
 361   GType typeGHashTable =
 362       dbus_g_type_get_map("GHashTable", G_TYPE_STRING, G_TYPE_VALUE);
 363   if (!dbus_g_proxy_call(aProxy, "GetAll", &error, G_TYPE_STRING,
 364                          "org.freedesktop.UPower.Device", G_TYPE_INVALID,
 365                          typeGHashTable, &hashTable, G_TYPE_INVALID)) {
 366     HAL_LOG("Error: %s\n", error->message);
 367     g_error_free(error);
 368     return nullptr;
 369   }
 370
 371   return hashTable;
 372 }
 373
 374 /* static */
 375 void UPowerClient::GetDevicePropertiesCallback(DBusGProxy* aProxy,
 376                                                DBusGProxyCall* aCall,
 377                                                void* aData) {
 378   GError* error = nullptr;
 379   GHashTable* hashTable = nullptr;
 380   GType typeGHashTable =
 381       dbus_g_type_get_map("GHashTable", G_TYPE_STRING, G_TYPE_VALUE);
 382   if (!dbus_g_proxy_end_call(aProxy, aCall, &error, typeGHashTable, &hashTable,
 383                              G_TYPE_INVALID)) {
 384     HAL_LOG("Error: %s\n", error->message);
 385     g_error_free(error);
 386   } else {
 387     sInstance->UpdateSavedInfo(hashTable);
 388     hal::NotifyBatteryChange(hal::BatteryInformation(
 389         sInstance->mLevel, sInstance->mCharging, sInstance->mRemainingTime));
 390     g_hash_table_unref(hashTable);
 391   }
 392 }
 393
 394 void UPowerClient::GetDevicePropertiesAsync(DBusGProxy* aProxy) {
 395   dbus_g_proxy_begin_call(aProxy, "GetAll", GetDevicePropertiesCallback,
 396                           nullptr, nullptr, G_TYPE_STRING,
 397                           "org.freedesktop.UPower.Device", G_TYPE_INVALID);
 398 }
 399
 400 void UPowerClient::UpdateSavedInfo(GHashTable* aHashTable) {
 401   bool isFull = false;
 402
 403   /*
 404    * State values are confusing...
 405    * First of all, after looking at upower sources (0.9.13), it seems that
 406    * PendingDischarge and PendingCharge are not used.
 407    * In addition, FullyCharged and Empty states are not clear because we do not
 408    * know if the battery is actually charging or not. Those values come directly
 409    * from sysfs (in the Linux kernel) which have four states: "Empty", "Full",
 410    * "Charging" and "Discharging". In sysfs, "Empty" and "Full" are also only
 411    * related to the level, not to the charging state.
 412    * In this code, we are going to assume that Full means charging and Empty
 413    * means discharging because if that is not the case, the state should not
 414    * last a long time (actually, it should disappear at the following update).
 415    * It might be even very hard to see real cases where the state is Empty and
 416    * the battery is charging or the state is Full and the battery is discharging
 417    * given that plugging/unplugging the battery should have an impact on the
 418    * level.
 419    */
 420   switch (g_value_get_uint(
 421       static_cast<const GValue*>(g_hash_table_lookup(aHashTable, "State")))) {
 422     case eState_Unknown:
 423       mCharging = kDefaultCharging;
 424       break;
 425     case eState_FullyCharged:
 426       isFull = true;
 427       [[fallthrough]];
 428     case eState_Charging:
 429     case eState_PendingCharge:
 430       mCharging = true;
 431       break;
 432     case eState_Discharging:
 433     case eState_Empty:
 434     case eState_PendingDischarge:
 435       mCharging = false;
 436       break;
 437   }
 438
 439   /*
 440    * The battery level might be very close to 100% (like 99%) without
 441    * increasing. It seems that upower sets the battery state as 'full' in that
 442    * case so we should trust it and not even try to get the value.
 443    */
 444   if (isFull) {
 445     mLevel = 1.0;
 446   } else {
 447     mLevel = round(g_value_get_double(static_cast<const GValue*>(
 448                  g_hash_table_lookup(aHashTable, "Percentage")))) *
 449              0.01;
 450   }
 451
 452   if (isFull) {
 453     mRemainingTime = 0;
 454   } else {
 455     mRemainingTime = mCharging
 456                          ? g_value_get_int64(static_cast<const GValue*>(
 457                                g_hash_table_lookup(aHashTable, "TimeToFull")))
 458                          : g_value_get_int64(static_cast<const GValue*>(
 459                                g_hash_table_lookup(aHashTable, "TimeToEmpty")));
 460
 461     if (mRemainingTime == kUPowerUnknownRemainingTime) {
 462       mRemainingTime = kUnknownRemainingTime;
 463     }
 464   }
 465 }
 466
 467 double UPowerClient::GetLevel() { return mLevel; }
 468
 469 bool UPowerClient::IsCharging() { return mCharging; }
 470
 471 double UPowerClient::GetRemainingTime() { return mRemainingTime; }
 472
 473 }  // namespace hal_impl
 474 }  // namespace mozilla