Implement UMA log throttling for cellular connections

components/metrics/data_use_tracker.h

Index: components/metrics/data_use_tracker.h
diff --git a/components/metrics/data_use_tracker.h b/components/metrics/data_use_tracker.h
new file mode 100644
index 0000000000000000000000000000000000000000..20d81449eb2eea67100a8a926b2a7713a54f6e3c
--- /dev/null
+++ b/components/metrics/data_use_tracker.h
@@ -0,0 +1,84 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.

[Alexei Svitkine (slow), 2016/03/29 16:29:10]

2016

[gayane -on leave until 09-2017, 2016/03/31 01:38:24]

Done.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_METRICS_DATA_USE_TRACKER_H_
+#define COMPONENTS_METRICS_DATA_USE_TRACKER_H_
+
+#include "base/callback.h"
+#include "base/gtest_prod_util.h"
+#include "base/memory/weak_ptr.h"
+#include "components/prefs/pref_registry_simple.h"
+#include "components/prefs/pref_service.h"
+
+namespace metrics {
+
+class DataUseTracker {
+ public:
+  static void GetForwardingCallback(
+      base::WeakPtr<DataUseTracker> data_use_tracker,
+      base::Callback<void(base::Callback<void(const std::string&, int)>)>
+          reply_callback);
+
+  // Should be called on UI thread
+  static base::Callback<void(const std::string&, int)>
+  GetForwardingCallbackOnUIThread(
+      base::WeakPtr<DataUseTracker> data_use_tracker);

[Alexei Svitkine (slow), 2016/03/29 16:29:10]

This doesn't need to be exposed in the header - so you can make it a free
standing function in the anon namespace.

[gayane -on leave until 09-2017, 2016/03/31 01:38:24]

Done.

+
+  static void RegisterPrefs(PrefRegistrySimple* registry);
+
+  static void RunOnUI(base::Callback<void(const std::string&, int)> callback,
+                      const std::string& service_name,
+                      int message_size);
+
+  bool CanUploadUMALog(int log_bytes);
+
+  base::WeakPtr<DataUseTracker> GetWeakPtr();
+
+  DataUseTracker(PrefService* local_state);
+  ~DataUseTracker();
+
+ private:
+  FRIEND_TEST_ALL_PREFIXES(DataUseTrackerTest, CheckUpdateUsagePref);
+  FRIEND_TEST_ALL_PREFIXES(DataUseTrackerTest, CheckRemoveExpiredEntries);
+  FRIEND_TEST_ALL_PREFIXES(DataUseTrackerTest, CheckComputeTotalDataUse);
+  FRIEND_TEST_ALL_PREFIXES(DataUseTrackerTest, CheckCanUploadUMALog);
+
+  // Updates data usage prefs on UI thread as the request comes from net which
+  // is on IO thread, but Prefservice expects UI thread.
+  void UpdateMetricsUsagePrefsOnUIThread(const std::string& service_name,
+                                         int message_size);
+
+  // Removes entries from the dictionary prefs if they are more than 7 days old.
+  void RemoveExpiredEntries();
+
+  // Updates data usage prefs for a current date with the given message size.
+  void UpdateUsagePref(const std::string& pref_name, int message_size);
+
+  // Returns the current date as a string with a proper formatting.
+  std::string GetCurrentMeasurementDate();
+
+  // Computes data usage according to all the entries in the given dictionary
+  // prefs.
+  int ComputeTotalDataUse(std::string pref_name);
+
+  void RemoveExpiredEntriesForPref(const std::string& pref_name);
+  bool GetUmaQouta(int* qouta);

[Alexei Svitkine (slow), 2016/03/29 16:29:10]

Qouta -> Quota

[gayane -on leave until 09-2017, 2016/03/31 01:38:24]

Done.

+  bool GetUmaRatio(double* ratio);
+
+  // Only for testing.
+  void SetMeasurementDateForTesting(const std::string& date);
+  void SetUmaQoutaForTesting(int uma_qouta);
+  void SetUmaRatioForTesting(double uma_ratio);
+
+  PrefService* local_state_;
+
+  std::string date_for_testing_;
+  int uma_qouta_for_testing_;
+  double uma_ratio_for_testing_;
+
+  base::WeakPtrFactory<DataUseTracker> weak_ptr_factory_;
+};
+
+}  // namespace metrics
+#endif  // COMPONENTS_METRICS_DATA_USE_TRACKER_H_