[chromeos/about:power] Collect cpuidle and cpufreq stats

chrome/browser/chromeos/power/cpu_data_collector.h

+// Copyright 2014 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 CHROME_BROWSER_CHROMEOS_POWER_CPU_DATA_COLLECTOR_H_
+#define CHROME_BROWSER_CHROMEOS_POWER_CPU_DATA_COLLECTOR_H_
+
+#include <deque>
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/timer/timer.h"
+
+namespace chromeos {
+
+class CpuDataCollector {
+ public:
+  struct IdleSample {
+    base::Time time;
+    std::map<std::string, double> state_occupancy_percent;
+  };
+
+  struct FreqSample {
+    base::Time time;
+    std::map<int, double> freq_occupancy_percent;
+  };
+
+  typedef std::deque<IdleSample> IdleSampleDeque;
+  typedef std::deque<FreqSample> FreqSampleDeque;
+
+  // Returns a vector whose elements correspond to a deque of idle state

[Daniel Erat, 2014/01/30 15:47:51]

nit: move these descriptions down to the point where the members are defined --
accessors usually don't have any comments in chrome

+  // occupancy percentage of each CPU in the system. The deque at index <i>
+  // in the vector corresponds to CPU<i>.
+  const std::vector<IdleSampleDeque>& cpu_idle_state_data() const {
+    return cpu_idle_state_data_;
+  }
+
+  // Returns a vector whose elements correspond to a deque of frequency state
+  // occupancy percentage of each CPU in the system. The deque at index <i>
+  // in the vector corresponds to CPU<i>.
+  const std::vector<FreqSampleDeque>& cpu_freq_state_data() const {
+    return cpu_freq_state_data_;
+  }
+
+  CpuDataCollector();
+
+  void Start();
+
+  void Lock();
+  void Unlock();
+
+ private:
+  void PostCollectSample();
+
+  void CollectSample();
+
+  base::RepeatingTimer<CpuDataCollector> timer_;
+  std::vector<IdleSampleDeque> cpu_idle_state_data_;
+  std::vector<FreqSampleDeque> cpu_freq_state_data_;
+
+  DISALLOW_COPY_AND_ASSIGN(CpuDataCollector);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_POWER_CPU_DATA_COLLECTOR_H_