chrome/browser/chromeos/power/power_data_collector.h

   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 #ifndef CHROME_BROWSER_CHROMEOS_POWER_POWER_DATA_COLLECTOR_H_
   6 #define CHROME_BROWSER_CHROMEOS_POWER_POWER_DATA_COLLECTOR_H_
   7
   8 #include <deque>
   9
  10 #include "base/basictypes.h"
  11 #include "base/compiler_specific.h"
  12 #include "base/time/time.h"
  13 #include "chrome/browser/chromeos/power/cpu_data_collector.h"
  14 #include "chromeos/chromeos_export.h"
  15 #include "chromeos/dbus/power_manager_client.h"
  16
  17 namespace power_manager {
  18 class PowerSupplyProperties;
  19 }
  20
  21 namespace chromeos {
  22
  23 // A class which starts collecting power metrics, like the battery charge, as
  24 // soon as it is initialized via Initialize().
  25 //
  26 // This class is implemented as a global singleton, initialized after
  27 // DBusThreadManager which it depends on.
  28 class CHROMEOS_EXPORT PowerDataCollector : public PowerManagerClient::Observer {
  29  public:
  30   struct PowerSupplySample {
  31     PowerSupplySample();
  32
  33     // Time when the sample was captured. We use base::Time instead of
  34     // base::TimeTicks because the latter does not advance when the system is
  35     // suspended.
  36     base::Time time;
  37
  38     // True if connected to external power at the time of the sample.
  39     bool external_power;
  40
  41     // The battery charge as a percentage of full charge in range [0.0, 100.00].
  42     double battery_percent;
  43
  44     // The battery discharge rate in W. Positive if the battery is being
  45     // discharged and negative if it's being charged.
  46     double battery_discharge_rate;
  47   };
  48
  49   struct SystemResumedSample {
  50     SystemResumedSample();
  51
  52     // Time when the system resumed.
  53     base::Time time;
  54
  55     // The duration for which the system was in sleep/suspend state.
  56     base::TimeDelta sleep_duration;
  57   };
  58
  59   const std::deque<PowerSupplySample>& power_supply_data() const {
  60     return power_supply_data_;
  61   }
  62
  63   const std::deque<SystemResumedSample>& system_resumed_data() const {
  64     return system_resumed_data_;
  65   }
  66
  67   const CpuDataCollector& cpu_data_collector() const {
  68     return cpu_data_collector_;
  69   }
  70
  71   // Can be called only after DBusThreadManager is initialized.
  72   static void Initialize();
  73
  74   // Same as Initialize, but does not start the CpuDataCollector.
  75   static void InitializeForTesting();
  76
  77   // Can be called only if initialized via Initialize, and before
  78   // DBusThreadManager is destroyed.
  79   static void Shutdown();
  80
  81   // Returns the global instance of PowerDataCollector.
  82   static PowerDataCollector* Get();
  83
  84   // PowerManagerClient::Observer implementation:
  85   void PowerChanged(const power_manager::PowerSupplyProperties& prop) override;
  86   void SuspendDone(const base::TimeDelta& sleep_duration) override;
  87
  88   // Only those power data samples which fall within the last
  89   // |kSampleTimeLimitSec| are stored in memory.
  90   static const int kSampleTimeLimitSec;
  91
  92  private:
  93   explicit PowerDataCollector(const bool start_cpu_data_collector);
  94
  95   ~PowerDataCollector() override;
  96
  97   std::deque<PowerSupplySample> power_supply_data_;
  98   std::deque<SystemResumedSample> system_resumed_data_;
  99   CpuDataCollector cpu_data_collector_;
 100
 101   DISALLOW_COPY_AND_ASSIGN(PowerDataCollector);
 102 };
 103
 104 // Adds |sample| to |sample_deque|.
 105 // It dumps samples |PowerDataCollector::kSampleTimeLimitSec| or more older than
 106 // |sample|.
 107 template <typename SampleType>
 108 void AddSample(std::deque<SampleType>* sample_queue, const SampleType& sample) {
 109   while (!sample_queue->empty()) {
 110     const SampleType& first = sample_queue->front();
 111     if (sample.time - first.time >
 112         base::TimeDelta::FromSeconds(PowerDataCollector::kSampleTimeLimitSec)) {
 113       sample_queue->pop_front();
 114     } else {
 115       break;
 116     }
 117   }
 118   sample_queue->push_back(sample);
 119 }
 120
 121 }  // namespace chromeos
 122
 123 #endif  // CHROME_BROWSER_CHROMEOS_POWER_POWER_DATA_COLLECTOR_H_