[chromeos] New PowerManagerClient observer to collect power data.

The observer currently only collects power supply data. This CL
should be treated as the first in a series to address the
marked issue.

BUG=312956

Review URL: https://codereview.chromium.org/101963004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241445 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 205 insertions, 0 deletions

diff --git a/chromeos/chromeos.gyp b/chromeos/chromeos.gyp
index 635c705..3d74363 100644
--- a/chromeos/chromeos.gyp
+++ b/chromeos/chromeos.gyp
@@ -320,6 +320,8 @@
         'network/shill_property_util.h',
         'network/dhcp_proxy_script_fetcher_chromeos.cc',
         'network/dhcp_proxy_script_fetcher_chromeos.h',
+        'power/power_data_collector.cc',
+        'power/power_data_collector.h',
         'process_proxy/process_output_watcher.cc',
         'process_proxy/process_output_watcher.h',
         'process_proxy/process_proxy.cc',
@@ -515,6 +517,7 @@
         'network/onc/onc_validator_unittest.cc',
         'network/shill_property_handler_unittest.cc',
         'network/shill_property_util_unittest.cc',
+        'power/power_data_collector_unittest.cc',
         'process_proxy/process_output_watcher_unittest.cc',
         'process_proxy/process_proxy_unittest.cc',
         'system/name_value_pairs_parser_unittest.cc',
diff --git a/chromeos/power/power_data_collector.cc b/chromeos/power/power_data_collector.cc
new file mode 100644
index 0000000..cc84e5c
--- /dev/null
+++ b/chromeos/power/power_data_collector.cc
@@ -0,0 +1,70 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chromeos/power/power_data_collector.h"
+
+#include "base/logging.h"
+#include "chromeos/dbus/dbus_thread_manager.h"
+#include "chromeos/dbus/power_manager/power_supply_properties.pb.h"
+
+namespace chromeos {
+
+namespace {
+
+// The global PowerDataCollector instance.
+PowerDataCollector* g_power_data_collector = NULL;
+
+}  // namespace
+
+// static
+void PowerDataCollector::Initialize() {
+  // Check that power data collector is initialized only after the
+  // DBusThreadManager is initialized.
+  CHECK(DBusThreadManager::Get());
+  CHECK(g_power_data_collector == NULL);
+  g_power_data_collector = new PowerDataCollector();
+}
+
+// static
+void PowerDataCollector::Shutdown() {
+  // Shutdown only if initialized.
+  CHECK(g_power_data_collector);
+  delete g_power_data_collector;
+  g_power_data_collector = NULL;
+}
+
+// static
+PowerDataCollector* PowerDataCollector::Get() {
+  CHECK(g_power_data_collector);
+  return g_power_data_collector;
+}
+
+void PowerDataCollector::PowerChanged(
+    const power_manager::PowerSupplyProperties& prop) {
+  PowerSupplySnapshot snapshot;
+  snapshot.time = base::TimeTicks::Now();
+  snapshot.external_power = (prop.external_power() !=
+      power_manager::PowerSupplyProperties::DISCONNECTED);
+  snapshot.battery_percent = prop.battery_percent();
+
+  power_supply_data_.push_back(snapshot);
+}
+
+PowerDataCollector::PowerDataCollector() {
+  DBusThreadManager::Get()->GetPowerManagerClient()->AddObserver(this);
+}
+
+PowerDataCollector::~PowerDataCollector() {
+  DBusThreadManager* dbus_manager = DBusThreadManager::Get();
+  CHECK(dbus_manager);
+  dbus_manager->GetPowerManagerClient()->RemoveObserver(this);
+}
+
+PowerDataCollector::PowerSupplySnapshot::PowerSupplySnapshot()
+    : time(base::TimeTicks::Now()),
+      external_power(false),
+      battery_percent(0) {
+}
+
+}  // namespace chromeos
diff --git a/chromeos/power/power_data_collector.h b/chromeos/power/power_data_collector.h
new file mode 100644
index 0000000..581faa0
--- /dev/null
+++ b/chromeos/power/power_data_collector.h
@@ -0,0 +1,72 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROMEOS_POWER_POWER_DATA_COLLECTOR_H_
+#define CHROMEOS_POWER_POWER_DATA_COLLECTOR_H_
+
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/time/time.h"
+#include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/power_manager_client.h"
+
+namespace power_manager {
+class PowerSupplyProperties;
+}
+
+namespace chromeos {
+
+// A class which starts collecting power metrics, like the battery charge, as
+// soon as it is initialized via Initialize().
+//
+// This class is implemented as a global singleton, initialized after
+// DBusThreadManager which it depends on.
+class CHROMEOS_EXPORT PowerDataCollector : public PowerManagerClient::Observer {
+ public:
+  struct PowerSupplySnapshot {
+    PowerSupplySnapshot();
+
+    // Time when the snapshot was captured.
+    base::TimeTicks time;
+
+    // True if connected to external power at the time of the snapshot.
+    bool external_power;
+
+    // The battery charge as a percentage of full charge in range [0.0, 100.00].
+    double battery_percent;
+  };
+
+  const std::vector<PowerSupplySnapshot>& power_supply_data() const {
+    return power_supply_data_;
+  }
+
+  // Can be called only after DBusThreadManager is initialized.
+  static void Initialize();
+
+  // Can be called only if initialized via Initialize, and before
+  // DBusThreadManager is destroyed.
+  static void Shutdown();
+
+  // Returns the global instance of PowerDataCollector.
+  static PowerDataCollector* Get();
+
+  // PowerManagerClient::Observer implementation:
+  virtual void PowerChanged(
+      const power_manager::PowerSupplyProperties& prop) OVERRIDE;
+
+ private:
+  PowerDataCollector();
+
+  virtual ~PowerDataCollector();
+
+  std::vector<PowerSupplySnapshot> power_supply_data_;
+
+  DISALLOW_COPY_AND_ASSIGN(PowerDataCollector);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROMEOS_POWER_POWER_DATA_COLLECTOR_H_
diff --git a/chromeos/power/power_data_collector_unittest.cc b/chromeos/power/power_data_collector_unittest.cc
new file mode 100644
index 0000000..a04a4d8
--- /dev/null
+++ b/chromeos/power/power_data_collector_unittest.cc
@@ -0,0 +1,60 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chromeos/power/power_data_collector.h"
+#include "chromeos/dbus/dbus_thread_manager.h"
+#include "chromeos/dbus/fake_dbus_thread_manager.h"
+#include "chromeos/dbus/power_manager/power_supply_properties.pb.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace chromeos {
+
+class PowerDataCollectorTest : public testing::Test {
+ public:
+  PowerDataCollectorTest() : power_data_collector_(NULL) {}
+  virtual ~PowerDataCollectorTest() {}
+
+  virtual void SetUp() OVERRIDE {
+    FakeDBusThreadManager* fake_dbus_thread_manager = new FakeDBusThreadManager;
+    fake_dbus_thread_manager->SetFakeClients();
+    DBusThreadManager::InitializeForTesting(fake_dbus_thread_manager);
+    PowerDataCollector::Initialize();
+    power_data_collector_ = PowerDataCollector::Get();
+  }
+
+  virtual void TearDown() OVERRIDE {
+    PowerDataCollector::Shutdown();
+    DBusThreadManager::Shutdown();
+    power_data_collector_ = NULL;
+  }
+
+ protected:
+  PowerDataCollector* power_data_collector_;
+};
+
+TEST_F(PowerDataCollectorTest, PowerChanged) {
+  power_manager::PowerSupplyProperties prop1, prop2;
+
+  prop1.set_external_power(power_manager::PowerSupplyProperties::DISCONNECTED);
+  prop1.set_battery_percent(20.00);
+
+  power_data_collector_->PowerChanged(prop1);
+  const std::vector<PowerDataCollector::PowerSupplySnapshot>& data1 =
+      power_data_collector_->power_supply_data();
+  ASSERT_EQ(static_cast<size_t>(1), data1.size());
+  EXPECT_DOUBLE_EQ(prop1.battery_percent(), data1[0].battery_percent);
+  EXPECT_FALSE(data1[0].external_power);
+
+  prop2.set_external_power(power_manager::PowerSupplyProperties::AC);
+  prop2.set_battery_percent(100.00);
+
+  power_data_collector_->PowerChanged(prop2);
+  const std::vector<PowerDataCollector::PowerSupplySnapshot>& data2 =
+      power_data_collector_->power_supply_data();
+  ASSERT_EQ(static_cast<size_t>(2), data2.size());
+  EXPECT_DOUBLE_EQ(prop2.battery_percent(), data1[1].battery_percent);
+  EXPECT_TRUE(data2[1].external_power);
+}
+
+}  // namespace chromeos