We really only need to keep a handful of properties up-to-date for each upower device. Given that upower requires us to refetch all properties with GetAll whenever it signals that it's changed, we really don't need to keep bus proxies alive for each device.

Removing the autogenerated proxy code and just using a couple of the direct GDBusConnection API calls cuts out some unnecessary overhead according to health-check. See the before & after profile logs attached to the ticket. Fixes: https://bugs.launchpad.net/bugs/1221871.

Approved by Lars Uebernickel, PS Jenkins bot.

3 files changed, 128 insertions, 778 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index 92117fc..be746db 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -27,31 +27,12 @@ EXTRA_DIST += org.freedesktop.UPower.xml
 
 ###
 ###
-
-upower_device_dbus_sources = \
-  dbus-upower-device.c \
-  dbus-upower-device.h
-
-$(upower_device_dbus_sources): org.freedesktop.UPower.Device.xml
-	$(AM_V_GEN) gdbus-codegen \
-	  --c-namespace Dbus \
-	  --interface-prefix org.freedesktop.UPower \
-	  --generate-c-code dbus-upower-device \
-          $^
-
-BUILT_SOURCES += $(upower_device_dbus_sources)
-CLEANFILES += $(upower_device_dbus_sources)
-EXTRA_DIST += org.freedesktop.UPower.Device.xml
-
-###
-###
 ###
 
 noinst_LIBRARIES = libindicatorpower-upower.a libindicatorpower-service.a
 
 libindicatorpower_upower_a_SOURCES = \
   $(upower_dbus_sources) \
-  $(upower_device_dbus_sources) \
   device-provider-upower.c \
   device-provider-upower.h
 
diff --git a/src/device-provider-upower.c b/src/device-provider-upower.c
index 1b1b7bd..7c12beb 100644
--- a/src/device-provider-upower.c
+++ b/src/device-provider-upower.c
@@ -20,7 +20,6 @@
 #include "config.h"
 
 #include "dbus-upower.h"
-#include "dbus-upower-device.h"
 #include "device.h"
 #include "device-provider.h"
 #include "device-provider-upower.h"
@@ -34,6 +33,8 @@
 
 struct _IndicatorPowerDeviceProviderUPowerPriv
 {
+  GDBusConnection * bus;
+
   DbusUPower * upower_proxy;
   GHashTable * devices; /* dbus object path --> IndicatorPowerDevice */
   GCancellable * cancellable;
@@ -65,6 +66,12 @@ G_DEFINE_TYPE_WITH_CODE (
 ****  UPOWER DBUS
 ***/
 
+struct device_get_all_data
+{
+  char * path;
+  IndicatorPowerDeviceProviderUPower * self;
+};
+
 static void
 emit_devices_changed (IndicatorPowerDeviceProviderUPower * self)
 {
@@ -72,65 +79,97 @@ emit_devices_changed (IndicatorPowerDeviceProviderUPower * self)
 }
 
 static void
-on_upower_device_proxy_ready (GObject * o, GAsyncResult * res, gpointer gself)
+on_device_properties_ready (GObject * o, GAsyncResult * res, gpointer gdata)
 {
-  GError * err;
-  DbusDevice * tmp;
+  GError * error;
+  GVariant * response;
+  struct device_get_all_data * data = gdata;
 
-  err = NULL;
-  tmp = dbus_device_proxy_new_for_bus_finish (res, &err);
-  if (err != NULL)
+  error = NULL;
+  response = g_dbus_connection_call_finish (G_DBUS_CONNECTION(o), res, &error);
+  if (error != NULL)
     {
-      g_warning ("Unable to get UPower Device Proxy: %s", err->message);
-      g_error_free (err);
+      if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+        g_warning ("Error getting properties for UPower device '%s': %s",
+                   data->path, error->message);
+
+      g_error_free (error);
     }
   else
     {
-      /* use this proxy's properties to update our own IndicatorPowerDevice */
-
+      guint32 kind = 0;
+      guint32 state = 0;
+      gdouble percentage = 0;
+      gint64 time_to_empty = 0;
+      gint64 time_to_full = 0;
+      time_t time;
       IndicatorPowerDevice * device;
-      IndicatorPowerDeviceProviderUPower * self;
-      priv_t * p;
-
-      self = INDICATOR_POWER_DEVICE_PROVIDER_UPOWER (gself);
-      p = self->priv;
-
-      const guint kind = dbus_device_get_type_ (tmp);
-      const gdouble percentage = dbus_device_get_percentage (tmp);
-      const guint state = dbus_device_get_state (tmp);
-      const gint64 time_to_empty = dbus_device_get_time_to_empty (tmp);
-      const gint64 time_to_full = dbus_device_get_time_to_full (tmp);
-      const time_t time = time_to_empty ? time_to_empty : time_to_full;
-      const char * path = g_dbus_proxy_get_object_path (G_DBUS_PROXY (tmp));
-
-      device = indicator_power_device_new (path,
-                                           kind,
-                                           percentage,
-                                           state,
-                                           time);
-
-      g_hash_table_insert (p->devices,
-                           g_strdup (path),
-                           g_object_ref (device));
-
-      emit_devices_changed (self);
-
-      g_object_unref (device);
-      g_object_unref (tmp);
+      IndicatorPowerDeviceProviderUPowerPriv * p = data->self->priv;
+      GVariant * dict = g_variant_get_child_value (response, 0);
+
+      g_variant_lookup (dict, "Type", "u", &kind);
+      g_variant_lookup (dict, "State", "u", &state);
+      g_variant_lookup (dict, "Percentage", "d", &percentage);
+      g_variant_lookup (dict, "TimeToEmpty", "x", &time_to_empty);
+      g_variant_lookup (dict, "TimeToFull", "x", &time_to_full);
+      time = time_to_empty ? time_to_empty : time_to_full;
+
+      if ((device = g_hash_table_lookup (p->devices, data->path)))
+        {
+          g_object_set (device, INDICATOR_POWER_DEVICE_KIND, (gint)kind,
+                                INDICATOR_POWER_DEVICE_STATE, (gint)state,
+                                INDICATOR_POWER_DEVICE_OBJECT_PATH, data->path,
+                                INDICATOR_POWER_DEVICE_PERCENTAGE, percentage,
+                                INDICATOR_POWER_DEVICE_TIME, (guint64)time,
+                                NULL);
+        }
+      else
+        {
+          device = indicator_power_device_new (data->path,
+                                               kind,
+                                               percentage,
+                                               state,
+                                               time);
+
+          g_hash_table_insert (p->devices,
+                               g_strdup (data->path),
+                               g_object_ref (device));
+
+          g_object_unref (device);
+        }
+
+      emit_devices_changed (data->self);
+      g_variant_unref (dict);
+      g_variant_unref (response);
     }
+
+  g_free (data->path);
+  g_slice_free (struct device_get_all_data, data);
 }
 
 static void
 update_device_from_object_path (IndicatorPowerDeviceProviderUPower * self,
                                 const char                         * path)
 {
-  dbus_device_proxy_new_for_bus (G_BUS_TYPE_SYSTEM,
-                                 G_DBUS_PROXY_FLAGS_NONE,
-                                 BUS_NAME,
-                                 path,
-                                 self->priv->cancellable,
-                                 on_upower_device_proxy_ready,
-                                 self);
+  priv_t * p = self->priv;
+  struct device_get_all_data * data;
+
+  data = g_slice_new (struct device_get_all_data);
+  data->path = g_strdup (path);
+  data->self = self;
+
+  g_dbus_connection_call (p->bus,
+                          BUS_NAME,
+                          path,
+                          "org.freedesktop.DBus.Properties",
+                          "GetAll",
+                          g_variant_new ("(s)", "org.freedesktop.UPower.Device"),
+                          G_VARIANT_TYPE("(a{sv})"),
+                          G_DBUS_CALL_FLAGS_NO_AUTO_START,
+                          -1, /* default timeout */
+                          p->cancellable,
+                          on_device_properties_ready,
+                          data);
 }
 
 /*
@@ -273,7 +312,7 @@ on_upower_proxy_ready (GObject        * source G_GNUC_UNUSED,
   DbusUPower * proxy;
 
   err = NULL;
-  proxy = dbus_upower_proxy_new_for_bus_finish (res, &err);
+  proxy = dbus_upower_proxy_new_finish (res, &err);
   if (err != NULL)
     {
       g_warning ("Unable to get UPower proxy: %s", err->message);
@@ -304,6 +343,42 @@ on_upower_proxy_ready (GObject        * source G_GNUC_UNUSED,
     }
 }
 
+static void
+on_bus_ready (GObject * source_object G_GNUC_UNUSED,
+              GAsyncResult * res,
+              gpointer gself)
+{
+  GError * error;
+  GDBusConnection * tmp;
+
+  error = NULL;
+  tmp = g_bus_get_finish (res, &error);
+  if (error != NULL)
+    {
+      if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+        g_warning ("Error acquiring bus: %s", error->message);
+      g_error_free (error);
+    }
+  else
+    {
+      IndicatorPowerDeviceProviderUPower * self;
+      priv_t * p;
+
+      self = INDICATOR_POWER_DEVICE_PROVIDER_UPOWER (gself);
+      p = self->priv;
+
+      p->bus = tmp;
+
+      dbus_upower_proxy_new (p->bus,
+                             G_DBUS_PROXY_FLAGS_GET_INVALIDATED_PROPERTIES,
+                             BUS_NAME,
+                             BUS_PATH,
+                             p->cancellable,
+                             on_upower_proxy_ready,
+                             self);
+    }
+}
+
 /***
 ****  IndicatorPowerDeviceProvider virtual functions
 ***/
@@ -357,6 +432,8 @@ my_dispose (GObject * o)
 
   g_hash_table_remove_all (p->devices);
 
+  g_clear_object (&p->bus);
+
   G_OBJECT_CLASS (indicator_power_device_provider_upower_parent_class)->dispose (o);
 }
 
@@ -420,13 +497,10 @@ indicator_power_device_provider_upower_init (IndicatorPowerDeviceProviderUPower
                                            g_free,
                                            NULL);
 
-  dbus_upower_proxy_new_for_bus (G_BUS_TYPE_SYSTEM,
-                                 G_DBUS_PROXY_FLAGS_GET_INVALIDATED_PROPERTIES,
-                                 BUS_NAME,
-                                 BUS_PATH,
-                                 p->cancellable,
-                                 on_upower_proxy_ready,
-                                 self);
+  g_bus_get (G_BUS_TYPE_SYSTEM,
+             p->cancellable,
+             on_bus_ready,
+             self);
 }
 
 /***
diff --git a/src/org.freedesktop.UPower.Device.xml b/src/org.freedesktop.UPower.Device.xml
deleted file mode 100644
index 7c9a65b..0000000
--- a/src/org.freedesktop.UPower.Device.xml
+++ /dev/null
@@ -1,705 +0,0 @@
-<!DOCTYPE node PUBLIC
-"-//freedesktop//DTD D-BUS Object Introspection 1.0//EN"
-"http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd" [
-  <!ENTITY ERROR_GENERAL "org.freedesktop.UPower.Device.GeneralError">
-]>
-<node name="/" xmlns:doc="http://www.freedesktop.org/dbus/1.0/doc.dtd">
-  <interface name="org.freedesktop.UPower.Device">
-    <doc:doc>
-      <doc:description>
-        <doc:para>
-          Objects implementing this interface are usually discovered through
-          the <doc:tt>org.freedesktop.UPower</doc:tt> interface on
-          the <doc:tt>/org/freedesktop/UPower</doc:tt> object on
-          the D-Bus system bus service with the well-known
-          name <doc:tt>org.freedesktop.UPower</doc:tt> using
-          the
-          <doc:ref type="method" to="Power.EnumerateDevices">EnumerateDevices</doc:ref>
-          method.
-        </doc:para>
-        <doc:para>
-          <doc:example language="shell" title="simple example">
-            <doc:code>
-$ dbus-send --print-reply \
-            --system \
-            --dest=org.freedesktop.UPower \
-            /org/freedesktop/UPower/devices/battery_BAT0 \
-            org.freedesktop.DBus.Properties.GetAll \
-            string:org.freedesktop.UPower.Device
-
-method return sender=:1.386 -> dest=:1.477 reply_serial=2
-   array [
-      dict entry(
-         string "native-path"
-         variant             string "/sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:01/PNP0C09:00/PNP0C0A:00/power_supply/BAT0"
-      )
-      dict entry(
-         string "vendor"
-         variant             string "SONY"
-      )
-      dict entry(
-         string "model"
-         variant             string "42T4568"
-      )
-      dict entry(
-         string "serial"
-         variant             string "4179"
-      )
-      dict entry(
-         string "update-time"
-         variant             uint64 1226417875
-      )
-      dict entry(
-         string "type"
-         variant             uint 2
-      )
-      dict entry(
-         string "power-supply"
-         variant             boolean true
-      )
-      dict entry(
-         string "has-history"
-         variant             boolean true
-      )
-      dict entry(
-         string "has-statistics"
-         variant             boolean true
-      )
-      dict entry(
-         string "online"
-         variant             boolean false
-      )
-      dict entry(
-         string "energy"
-         variant             double 72.85
-      )
-      dict entry(
-         string "energy-empty"
-         variant             double 0
-      )
-      dict entry(
-         string "energy-full"
-         variant             double 74.55
-      )
-      dict entry(
-         string "energy-full-design"
-         variant             double 74.88
-      )
-      dict entry(
-         string "energy-rate"
-         variant             double 0
-      )
-      dict entry(
-         string "voltage"
-         variant             double 16.415
-      )
-      dict entry(
-         string "time-to-empty"
-         variant             int64 0
-      )
-      dict entry(
-         string "time-to-full"
-         variant             int64 0
-      )
-      dict entry(
-         string "percentage"
-         variant             double 97.7197
-      )
-      dict entry(
-         string "is-present"
-         variant             boolean true
-      )
-      dict entry(
-         string "state"
-         variant             uint 3
-      )
-      dict entry(
-         string "is-rechargeable"
-         variant             boolean true
-      )
-      dict entry(
-         string "capacity"
-         variant             double 100
-      )
-      dict entry(
-         string "technology"
-         variant             uint 1
-      )
-   ]
-            </doc:code>
-          </doc:example>
-        </doc:para>
-        <doc:para>
-          Unless otherwise noted, an empty string or the value 0 in a
-          property on this interface means not set.
-        </doc:para>
-      </doc:description>
-    </doc:doc>
-
-
-    <!-- ************************************************************ -->
-    <method name="Refresh">
-      <annotation name="org.freedesktop.DBus.GLib.Async" value=""/>
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            Refreshes the data collected from the power source.
-          </doc:para>
-        </doc:description>
-        <doc:permission>Callers need the org.freedesktop.upower.refresh-power-source authorization</doc:permission>
-        <doc:errors>
-          <doc:error name="&ERROR_GENERAL;">if an error occured while refreshing</doc:error>
-        </doc:errors>
-      </doc:doc>
-    </method>
-
-    <!-- ************************************************************ -->
-    <signal name="Changed">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            Some value on the power source changed.
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </signal>
-
-    <!-- ************************************************************ -->
-    <method name="GetHistory">
-      <annotation name="org.freedesktop.DBus.GLib.Async" value=""/>
-      <arg name="type" direction="in" type="s">
-        <doc:doc><doc:summary>The type of history.
-        Valid types are <doc:tt>rate</doc:tt> or <doc:tt>charge</doc:tt>.</doc:summary></doc:doc>
-      </arg>
-      <arg name="timespan" direction="in" type="u">
-        <doc:doc><doc:summary>The amount of data to return in seconds, or 0 for all.</doc:summary></doc:doc>
-      </arg>
-      <arg name="resolution" direction="in" type="u">
-        <doc:doc>
-          <doc:summary>
-            The approximate number of points to return.
-            A higher resolution is more accurate, at the expense of plotting speed.
-          </doc:summary>
-        </doc:doc>
-      </arg>
-      <arg name="data" direction="out" type="a(udu)">
-        <doc:doc><doc:summary>
-            The history data for the power device, if the device supports history.
-            Data is ordered from the earliest in time, to the newest data point.
-            Each element contains the following members:
-            <doc:list>
-              <doc:item>
-                <doc:term>time</doc:term>
-                <doc:definition>
-                  The time value in seconds from the <doc:tt>gettimeofday()</doc:tt> method.
-                </doc:definition>
-              </doc:item>
-              <doc:item>
-                <doc:term>value</doc:term>
-                <doc:definition>
-                  The data value, for instance the rate in W or the charge in %.
-                </doc:definition>
-              </doc:item>
-              <doc:item>
-                <doc:term>state</doc:term>
-                <doc:definition>
-                  The state of the device, for instance <doc:tt>charging</doc:tt> or
-                  <doc:tt>discharging</doc:tt>.
-                </doc:definition>
-              </doc:item>
-            </doc:list>
-        </doc:summary></doc:doc>
-      </arg>
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            Gets history for the power device that is persistent across reboots.
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </method>
-
-    <!-- ************************************************************ -->
-    <method name="GetStatistics">
-      <annotation name="org.freedesktop.DBus.GLib.Async" value=""/>
-      <arg name="type" direction="in" type="s">
-        <doc:doc><doc:summary>The mode for the statistics.
-        Valid types are <doc:tt>charging</doc:tt> or <doc:tt>discharging</doc:tt>.</doc:summary></doc:doc>
-      </arg>
-      <arg name="data" direction="out" type="a(dd)">
-        <doc:doc><doc:summary>
-            The statistics data for the power device.
-            Each element contains the following members:
-            <doc:list>
-              <doc:item>
-                <doc:term>value</doc:term>
-                <doc:definition>
-                  The value of the percentage point, usually in seconds
-                </doc:definition>
-              </doc:item>
-              <doc:item>
-                <doc:term>accuracy</doc:term>
-                <doc:definition>
-                  The accuracy of the prediction in percent.
-                </doc:definition>
-              </doc:item>
-            </doc:list>
-        </doc:summary></doc:doc>
-      </arg>
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            Gets statistics for the power device that may be interesting
-            to show on a graph in the session.
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </method>
-
-    <!-- ************************************************************ -->
-    <property name="NativePath" type="s" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            OS specific native path of the power source. On Linux this
-            is the sysfs path, for
-            example <doc:tt>/sys/devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT0</doc:tt>. Is
-            blank if the device is being driven by a user space
-            driver.
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="Vendor" type="s" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            Name of the vendor of the battery.
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="Model" type="s" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            Name of the model of this battery.
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="Serial" type="s" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            Unique serial number of the battery.
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="UpdateTime" type="t" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            The point in time (seconds since the Epoch Jan 1, 1970
-            0:00 UTC) that data was read from the power source.
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="Type" type="u" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            Type of power source.
-          </doc:para>
-          <doc:list>
-            <doc:item>
-              <doc:term>0</doc:term><doc:definition>Unknown</doc:definition>
-            </doc:item>
-            <doc:item>
-              <doc:term>1</doc:term><doc:definition>Line Power</doc:definition>
-            </doc:item>
-            <doc:item>
-              <doc:term>2</doc:term><doc:definition>Battery</doc:definition>
-            </doc:item>
-            <doc:item>
-              <doc:term>3</doc:term><doc:definition>Ups</doc:definition>
-            </doc:item>
-            <doc:item>
-              <doc:term>4</doc:term><doc:definition>Monitor</doc:definition>
-            </doc:item>
-            <doc:item>
-              <doc:term>5</doc:term><doc:definition>Mouse</doc:definition>
-            </doc:item>
-            <doc:item>
-              <doc:term>6</doc:term><doc:definition>Keyboard</doc:definition>
-            </doc:item>
-            <doc:item>
-              <doc:term>7</doc:term><doc:definition>Pda</doc:definition>
-            </doc:item>
-            <doc:item>
-              <doc:term>8</doc:term><doc:definition>Phone</doc:definition>
-            </doc:item>
-          </doc:list>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="PowerSupply" type="b" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            If the power device is used to supply the system.
-            This would be set TRUE for laptop batteries and UPS devices,
-            but set FALSE for wireless mice or PDAs.
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="HasHistory" type="b" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            If the power device has history.
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="HasStatistics" type="b" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            If the power device has statistics.
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="Online" type="b" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            Whether power is currently being provided through line power.
-            This property is only valid if the property
-            <doc:ref type="property" to="Source:Type">type</doc:ref>
-            has the value "line-power".
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="Energy" type="d" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            Amount of energy (measured in Wh) currently available in
-            the power source.
-          </doc:para><doc:para>
-            This property is only valid if the property
-            <doc:ref type="property" to="Source:Type">type</doc:ref>
-            has the value "battery".
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="EnergyEmpty" type="d" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            Amount of energy (measured in Wh) in the power source when
-            it's considered to be empty.
-          </doc:para><doc:para>
-            This property is only valid if the property
-            <doc:ref type="property" to="Source:Type">type</doc:ref>
-            has the value "battery".
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="EnergyFull" type="d" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            Amount of energy (measured in Wh) in the power source when
-            it's considered full.
-          </doc:para><doc:para>
-            This property is only valid if the property
-            <doc:ref type="property" to="Source:Type">type</doc:ref>
-            has the value "battery".
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="EnergyFullDesign" type="d" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            Amount of energy (measured in Wh) the power source is
-            designed to hold when it's considered full.
-          </doc:para><doc:para>
-            This property is only valid if the property
-            <doc:ref type="property" to="Source:Type">type</doc:ref>
-            has the value "battery".
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="EnergyRate" type="d" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            Amount of energy being drained from the source, measured
-            in W. If positive, the source is being discharged, if
-            negative it's being charged.
-          </doc:para><doc:para>
-            This property is only valid if the property
-            <doc:ref type="property" to="Source:Type">type</doc:ref>
-            has the value "battery".
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="Voltage" type="d" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            Voltage in the Cell or being recorded by the meter.
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="TimeToEmpty" type="x" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            Number of seconds until the power source is considered empty.
-            Is set to 0 if unknown.
-          </doc:para><doc:para>
-            This property is only valid if the property
-            <doc:ref type="property" to="Source:Type">type</doc:ref>
-            has the value "battery".
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="TimeToFull" type="x" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            Number of seconds until the power source is considered full.
-            Is set to 0 if unknown.
-          </doc:para><doc:para>
-            This property is only valid if the property
-            <doc:ref type="property" to="Source:Type">type</doc:ref>
-            has the value "battery".
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="Percentage" type="d" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            The amount of energy left in the power source expressed as
-            a percentage between 0 and 100. Typically this is the same as
-            (<doc:ref type="property" to="Source:Energy">energy</doc:ref> -
-            <doc:ref type="property" to="Source:EnergyEmpty">energy-empty</doc:ref>) /
-            (<doc:ref type="property" to="Source:EnergyFull">energy-full</doc:ref> -
-            <doc:ref type="property" to="Source:EnergyEmpty">energy-empty</doc:ref>).
-            However, some primitive power sources are capable of only
-            reporting percentages and in this case the energy-*
-            properties will be unset while this property is set.
-          </doc:para><doc:para>
-            This property is only valid if the property
-            <doc:ref type="property" to="Source:Type">type</doc:ref>
-            has the value "battery".
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="IsPresent" type="b" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            If the power source is present in the bay.
-            This field is required as some batteries are hot-removable, for example
-            expensive UPS and most laptop batteries.
-          </doc:para><doc:para>
-            This property is only valid if the property
-            <doc:ref type="property" to="Source:Type">type</doc:ref>
-            has the value "battery".
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="State" type="u" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            The battery power state.
-          </doc:para>
-          <doc:list>
-            <doc:item>
-              <doc:term>0</doc:term><doc:definition>Unknown</doc:definition>
-            </doc:item>
-            <doc:item>
-              <doc:term>1</doc:term><doc:definition>Charging</doc:definition>
-            </doc:item>
-            <doc:item>
-              <doc:term>2</doc:term><doc:definition>Discharging</doc:definition>
-            </doc:item>
-            <doc:item>
-              <doc:term>3</doc:term><doc:definition>Empty</doc:definition>
-            </doc:item>
-            <doc:item>
-              <doc:term>4</doc:term><doc:definition>Fully charged</doc:definition>
-            </doc:item>
-            <doc:item>
-              <doc:term>5</doc:term><doc:definition>Pending charge</doc:definition>
-            </doc:item>
-            <doc:item>
-              <doc:term>6</doc:term><doc:definition>Pending discharge</doc:definition>
-            </doc:item>
-          </doc:list>
-          <doc:para>
-            This property is only valid if the property
-            <doc:ref type="property" to="Source:Type">type</doc:ref>
-            has the value "battery".
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="IsRechargeable" type="b" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            If the power source is rechargeable.
-          </doc:para><doc:para>
-            This property is only valid if the property
-            <doc:ref type="property" to="Source:Type">type</doc:ref>
-            has the value "battery".
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="Capacity" type="d" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            The capacity of the power source expressed as a percentage between 0 and 100.
-            The capacity of the battery will reduce with age.
-            A capacity value less than 75% is usually a sign that you should renew your battery.
-            Typically this value is the same as
-            (<doc:ref type="property" to="Source:FullDesign">full-design</doc:ref> /
-            <doc:ref type="property" to="Source:Full">full</doc:ref>) * 100.
-            However, some primitive power sources are not capable reporting capacity
-            and in this case the capacity property will be unset.
-          </doc:para><doc:para>
-            This property is only valid if the property
-            <doc:ref type="property" to="Source:Type">type</doc:ref>
-            has the value "battery".
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="Technology" type="u" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            Technology used in the battery:
-          </doc:para>
-          <doc:list>
-            <doc:item>
-              <doc:term>0</doc:term><doc:definition>Unknown</doc:definition>
-            </doc:item>
-            <doc:item>
-              <doc:term>1</doc:term><doc:definition>Lithium ion</doc:definition>
-            </doc:item>
-            <doc:item>
-              <doc:term>2</doc:term><doc:definition>Lithium polymer</doc:definition>
-            </doc:item>
-            <doc:item>
-              <doc:term>3</doc:term><doc:definition>Lithium iron phosphate</doc:definition>
-            </doc:item>
-            <doc:item>
-              <doc:term>4</doc:term><doc:definition>Lead acid</doc:definition>
-            </doc:item>
-            <doc:item>
-              <doc:term>5</doc:term><doc:definition>Nickel cadmium</doc:definition>
-            </doc:item>
-            <doc:item>
-              <doc:term>6</doc:term><doc:definition>Nickel metal hydride</doc:definition>
-            </doc:item>
-          </doc:list>
-          <doc:para>
-            This property is only valid if the property
-            <doc:ref type="property" to="Source:Type">type</doc:ref>
-            has the value "battery".
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="RecallNotice" type="b" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            If the device may have been recalled by the vendor due to a suspected
-            fault.
-            This key does not imply the device is faulty, only that it approximatly
-            matches the description from the vendor of units that were recalled.
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="RecallVendor" type="s" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            The vendor that is handling the hardware recall.
-          </doc:para>
-          <doc:para>
-            This property is only valid if the property recall-notice is true.
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-    <property name="RecallUrl" type="s" access="read">
-      <doc:doc>
-        <doc:description>
-          <doc:para>
-            The URL to visit about the hardware recall.
-          </doc:para>
-          <doc:para>
-            This property is only valid if the property recall-notice is true.
-          </doc:para>
-        </doc:description>
-      </doc:doc>
-    </property>
-
-  </interface>
-
-</node>