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 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

 /* 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 http://mozilla.org/MPL/2.0/. */

 #include <mozilla/Hal.h>

 #include <dbus/dbus-glib.h>

 #include <dbus/dbus-glib-lowlevel.h>

 #include <mozilla/dom/battery/Constants.h>

 #include "nsAutoRef.h"

 /*

  * Helper that manages the destruction of glib objects as soon as they leave

  * the current scope.

  *

  * We are specializing nsAutoRef class.

  */

 template <>

 class nsAutoRefTraits<GHashTable> : public nsPointerRefTraits<GHashTable>

 {

 public:

   static void Release(GHashTable* ptr) { g_hash_table_unref(ptr); }

 };

 using namespace mozilla::dom::battery;

 namespace mozilla {

 namespace hal_impl {

 /**

  * This is the declaration of UPowerClient class. This class is listening and

  * communicating to upower daemon through DBus.

  * There is no header file because this class shouldn't be public.

  */

 class UPowerClient

 {

 public:

   static UPowerClient* GetInstance();

   void BeginListening();

   void StopListening();

   double GetLevel();

   bool   IsCharging();

   double GetRemainingTime();

   ~UPowerClient();

 private:

   UPowerClient();

   enum States {

     eState_Unknown = 0,

     eState_Charging,

     eState_Discharging,

     eState_Empty,

     eState_FullyCharged,

     eState_PendingCharge,

     eState_PendingDischarge

   };

   /**

    * Update the currently tracked device.

    * @return whether everything went ok.

    */

   void UpdateTrackedDeviceSync();

   /**

    * Returns a hash table with the properties of aDevice.

    * Note: the caller has to unref the hash table.

    */

   GHashTable* GetDevicePropertiesSync(DBusGProxy* aProxy);

   void GetDevicePropertiesAsync(DBusGProxy* aProxy);

   static void GetDevicePropertiesCallback(DBusGProxy* aProxy,

                                           DBusGProxyCall* aCall,

                                           void* aData);

   /**

    * Using the device properties (aHashTable), this method updates the member

    * variable storing the values we care about.

    */

   void UpdateSavedInfo(GHashTable* aHashTable);

   /**

    * Callback used by 'DeviceChanged' signal.

    */

   static void DeviceChanged(DBusGProxy* aProxy, const gchar* aObjectPath,

                             UPowerClient* aListener);

   /**

    * Callback called when mDBusConnection gets a signal.

    */

   static DBusHandlerResult ConnectionSignalFilter(DBusConnection* aConnection,

                                                   DBusMessage* aMessage,

                                                   void* aData);

   // The DBus connection object.

   DBusGConnection* mDBusConnection;

   // The DBus proxy object to upower.

   DBusGProxy* mUPowerProxy;

   // The path of the tracked device.

   gchar* mTrackedDevice;

   // The DBusGProxy for the tracked device.

   DBusGProxy* mTrackedDeviceProxy;

   double mLevel;

   bool mCharging;

   double mRemainingTime;

   static UPowerClient* sInstance;

   static const guint sDeviceTypeBattery = 2;

   static const guint64 kUPowerUnknownRemainingTime = 0;

 };

 /*

  * Implementation of mozilla::hal_impl::EnableBatteryNotifications,

  *                   mozilla::hal_impl::DisableBatteryNotifications,

  *               and mozilla::hal_impl::GetCurrentBatteryInformation.

  */

 void

 EnableBatteryNotifications()

 {

   UPowerClient::GetInstance()->BeginListening();

 }

 void

 DisableBatteryNotifications()

 {

   UPowerClient::GetInstance()->StopListening();

 }

 void

 GetCurrentBatteryInformation(hal::BatteryInformation* aBatteryInfo)

 {

   UPowerClient* upowerClient = UPowerClient::GetInstance();

   aBatteryInfo->level() = upowerClient->GetLevel();

   aBatteryInfo->charging() = upowerClient->IsCharging();

   aBatteryInfo->remainingTime() = upowerClient->GetRemainingTime();

 }

 /*

  * Following is the implementation of UPowerClient.

  */

 UPowerClient* UPowerClient::sInstance = nullptr;

 /* static */ UPowerClient*

 UPowerClient::GetInstance()

 {

   if (!sInstance) {

     sInstance = new UPowerClient();

   }

   return sInstance;

 }

 UPowerClient::UPowerClient()

   : mDBusConnection(nullptr)

   , mUPowerProxy(nullptr)

   , mTrackedDevice(nullptr)

   , mTrackedDeviceProxy(nullptr)

   , mLevel(kDefaultLevel)

   , mCharging(kDefaultCharging)

   , mRemainingTime(kDefaultRemainingTime)

 {

 }

 UPowerClient::~UPowerClient()

 {

   NS_ASSERTION(!mDBusConnection && !mUPowerProxy && !mTrackedDevice && !mTrackedDeviceProxy,

                "The observers have not been correctly removed! "

                "(StopListening should have been called)");

 }

 void

 UPowerClient::BeginListening()

 {

   GError* error = nullptr;

   mDBusConnection = dbus_g_bus_get(DBUS_BUS_SYSTEM, &error);

   if (!mDBusConnection) {

     g_printerr("Failed to open connection to bus: %s\n", error->message);

     g_error_free(error);

     return;

   }

   DBusConnection* dbusConnection =

     dbus_g_connection_get_connection(mDBusConnection);

   // Make sure we do not exit the entire program if DBus connection get lost.

   dbus_connection_set_exit_on_disconnect(dbusConnection, false);

   // Listening to signals the DBus connection is going to get so we will know

   // when it is lost and we will be able to disconnect cleanly.

   dbus_connection_add_filter(dbusConnection, ConnectionSignalFilter, this,

                              nullptr);

   mUPowerProxy = dbus_g_proxy_new_for_name(mDBusConnection,

                                            "org.freedesktop.UPower",

                                            "/org/freedesktop/UPower",

                                            "org.freedesktop.UPower");

   UpdateTrackedDeviceSync();

   /*

    * TODO: we should probably listen to DeviceAdded and DeviceRemoved signals.

    * If we do that, we would have to disconnect from those in StopListening.

    * It's not yet implemented because it requires testing hot plugging and

    * removal of a battery.

    */

   dbus_g_proxy_add_signal(mUPowerProxy, "DeviceChanged", G_TYPE_STRING,

                           G_TYPE_INVALID);

   dbus_g_proxy_connect_signal(mUPowerProxy, "DeviceChanged",

                               G_CALLBACK (DeviceChanged), this, nullptr);

 }

 void

 UPowerClient::StopListening()

 {

   // If mDBusConnection isn't initialized, that means we are not really listening.

   if (!mDBusConnection) {

     return;

   }

   dbus_connection_remove_filter(

       dbus_g_connection_get_connection(mDBusConnection),

       ConnectionSignalFilter, this);

   dbus_g_proxy_disconnect_signal(mUPowerProxy, "DeviceChanged",

                                  G_CALLBACK (DeviceChanged), this);

   g_free(mTrackedDevice);

   mTrackedDevice = nullptr;

   if (mTrackedDeviceProxy) {

     g_object_unref(mTrackedDeviceProxy);

     mTrackedDeviceProxy = nullptr;

   }

   g_object_unref(mUPowerProxy);

   mUPowerProxy = nullptr;

   dbus_g_connection_unref(mDBusConnection);

   mDBusConnection = nullptr;

   // We should now show the default values, not the latest we got.

   mLevel = kDefaultLevel;

   mCharging = kDefaultCharging;

   mRemainingTime = kDefaultRemainingTime;

 }

 void

 UPowerClient::UpdateTrackedDeviceSync()

 {

   GType typeGPtrArray = dbus_g_type_get_collection("GPtrArray",

                                                    DBUS_TYPE_G_OBJECT_PATH);

   GPtrArray* devices = nullptr;

   GError* error = nullptr;

   // Reset the current tracked device:

   g_free(mTrackedDevice);

   mTrackedDevice = nullptr;

   // Reset the current tracked device proxy:

   if (mTrackedDeviceProxy) {

     g_object_unref(mTrackedDeviceProxy);

     mTrackedDeviceProxy = nullptr;

   }

   // If that fails, that likely means upower isn't installed.

   if (!dbus_g_proxy_call(mUPowerProxy, "EnumerateDevices", &error, G_TYPE_INVALID,

                          typeGPtrArray, &devices, G_TYPE_INVALID)) {

     g_printerr ("Error: %s\n", error->message);

     g_error_free(error);

     return;

   }

   /*

    * We are looking for the first device that is a battery.

    * TODO: we could try to combine more than one battery.

    */

   for (guint i=0; i<devices->len; ++i) {

     gchar* devicePath = static_cast<gchar*>(g_ptr_array_index(devices, i));

     DBusGProxy* proxy = dbus_g_proxy_new_from_proxy(mUPowerProxy,

                                                     "org.freedesktop.DBus.Properties",

                                                     devicePath);

     nsAutoRef<GHashTable> hashTable(GetDevicePropertiesSync(proxy));

     if (g_value_get_uint(static_cast<const GValue*>(g_hash_table_lookup(hashTable, "Type"))) == sDeviceTypeBattery) {

       UpdateSavedInfo(hashTable);

       mTrackedDevice = devicePath;

       mTrackedDeviceProxy = proxy;

       break;

     }

     g_object_unref(proxy);

     g_free(devicePath);

   }

   g_ptr_array_free(devices, true);

 }

 /* static */ void

 UPowerClient::DeviceChanged(DBusGProxy* aProxy, const gchar* aObjectPath, UPowerClient* aListener)

 {

   if (!aListener->mTrackedDevice) {

     return;

   }

 #if GLIB_MAJOR_VERSION >= 2 && GLIB_MINOR_VERSION >= 16

   if (g_strcmp0(aObjectPath, aListener->mTrackedDevice)) {

 #else

   if (g_ascii_strcasecmp(aObjectPath, aListener->mTrackedDevice)) {

 #endif

     return;

   }

   aListener->GetDevicePropertiesAsync(aListener->mTrackedDeviceProxy);

 }

 /* static */ DBusHandlerResult

 UPowerClient::ConnectionSignalFilter(DBusConnection* aConnection,

                                      DBusMessage* aMessage, void* aData)

 {

   if (dbus_message_is_signal(aMessage, DBUS_INTERFACE_LOCAL, "Disconnected")) {

     static_cast<UPowerClient*>(aData)->StopListening();

     // We do not return DBUS_HANDLER_RESULT_HANDLED here because the connection

     // might be shared and some other filters might want to do something.

   }

   return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;

 }

 GHashTable*

 UPowerClient::GetDevicePropertiesSync(DBusGProxy* aProxy)

 {

   GError* error = nullptr;

   GHashTable* hashTable = nullptr;

   GType typeGHashTable = dbus_g_type_get_map("GHashTable", G_TYPE_STRING,

                                             G_TYPE_VALUE);

   if (!dbus_g_proxy_call(aProxy, "GetAll", &error, G_TYPE_STRING,

                          "org.freedesktop.UPower.Device", G_TYPE_INVALID,

                          typeGHashTable, &hashTable, G_TYPE_INVALID)) {

     g_printerr("Error: %s\n", error->message);

     g_error_free(error);

     return nullptr;

   }

   return hashTable;

 }

 /* static */ void

 UPowerClient::GetDevicePropertiesCallback(DBusGProxy* aProxy,

                                           DBusGProxyCall* aCall, void* aData)

 {

   GError* error = nullptr;

   GHashTable* hashTable = nullptr;

   GType typeGHashTable = dbus_g_type_get_map("GHashTable", G_TYPE_STRING,

                                              G_TYPE_VALUE);

   if (!dbus_g_proxy_end_call(aProxy, aCall, &error, typeGHashTable,

                              &hashTable, G_TYPE_INVALID)) {

     g_printerr("Error: %s\n", error->message);

     g_error_free(error);

   } else {

     sInstance->UpdateSavedInfo(hashTable);

     hal::NotifyBatteryChange(hal::BatteryInformation(sInstance->mLevel,

                                                      sInstance->mCharging,

                                                      sInstance->mRemainingTime));

     g_hash_table_unref(hashTable);

   }

 }

 void

 UPowerClient::GetDevicePropertiesAsync(DBusGProxy* aProxy)

 {

   dbus_g_proxy_begin_call(aProxy, "GetAll", GetDevicePropertiesCallback, nullptr,

                           nullptr, G_TYPE_STRING,

                           "org.freedesktop.UPower.Device", G_TYPE_INVALID);

 }

 void

 UPowerClient::UpdateSavedInfo(GHashTable* aHashTable)

 {

   bool isFull = false;

   /*

    * State values are confusing...

    * First of all, after looking at upower sources (0.9.13), it seems that

    * PendingDischarge and PendingCharge are not used.

    * In addition, FullyCharged and Empty states are not clear because we do not

    * know if the battery is actually charging or not. Those values come directly

    * from sysfs (in the Linux kernel) which have four states: "Empty", "Full",

    * "Charging" and "Discharging". In sysfs, "Empty" and "Full" are also only

    * related to the level, not to the charging state.

    * In this code, we are going to assume that Full means charging and Empty

    * means discharging because if that is not the case, the state should not

    * last a long time (actually, it should disappear at the following update).

    * It might be even very hard to see real cases where the state is Empty and

    * the battery is charging or the state is Full and the battery is discharging

    * given that plugging/unplugging the battery should have an impact on the

    * level.

    */

   switch (g_value_get_uint(static_cast<const GValue*>(g_hash_table_lookup(aHashTable, "State")))) {

     case eState_Unknown:

       mCharging = kDefaultCharging;

       break;

     case eState_FullyCharged:

       isFull = true;

     case eState_Charging:

     case eState_PendingCharge:

       mCharging = true;

       break;

     case eState_Discharging:

     case eState_Empty:

     case eState_PendingDischarge:

       mCharging = false;

       break;

   }

   /*

    * The battery level might be very close to 100% (like 99.xxxx%) without

    * increasing. It seems that upower sets the battery state as 'full' in that

    * case so we should trust it and not even try to get the value.

    */

   if (isFull) {

     mLevel = 1.0;

   } else {

     mLevel = g_value_get_double(static_cast<const GValue*>(g_hash_table_lookup(aHashTable, "Percentage")))*0.01;

   }

   if (isFull) {

     mRemainingTime = 0;

   } else {

     mRemainingTime = mCharging ? g_value_get_int64(static_cast<const GValue*>(g_hash_table_lookup(aHashTable, "TimeToFull")))

                                : g_value_get_int64(static_cast<const GValue*>(g_hash_table_lookup(aHashTable, "TimeToEmpty")));

     if (mRemainingTime == kUPowerUnknownRemainingTime) {

       mRemainingTime = kUnknownRemainingTime;

     }

   }

 }

 double

 UPowerClient::GetLevel()

 {

   return mLevel;

 }

 bool

 UPowerClient::IsCharging()

 {

   return mCharging;

 }

 double

 UPowerClient::GetRemainingTime()

 {

   return mRemainingTime;

 }

 } // namespace hal_impl

 } // namespace mozilla