Implement a persistent storage aggregation counter class.

metrics_daemon.h

 // Copyright (c) 2010 The Chromium OS 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 METRICS_DAEMON_H_
 #define METRICS_DAEMON_H_
 
 #include <dbus/dbus.h>
 #include <glib.h>
 
+#include <base/scoped_ptr.h>
+#include <base/time.h>
+#include <gtest/gtest_prod.h>  // for FRIEND_TEST
+
 #include "metrics_library.h"
 
-#include <gtest/gtest_prod.h>  // for FRIEND_TEST
-#include <base/time.h>
+namespace chromeos_metrics { class TaggedCounterInterface; }
 
 class MetricsDaemon {
 
  public:
-  MetricsDaemon()
-      : daily_use_record_file_(NULL),
-        network_state_(kUnknownNetworkState),
-        power_state_(kUnknownPowerState),
-        session_state_(kUnknownSessionState),
-        user_active_(false),
-        daily_use_day_last_(0),
-        usemon_interval_(0),
-        usemon_source_(NULL) {}
-  ~MetricsDaemon() {}
+  MetricsDaemon();
+  ~MetricsDaemon();
 
   // Initializes.
   void Init(bool testing, MetricsLibraryInterface* metrics_lib);
 
   // Does all the work. If |run_as_daemon| is true, daemonizes by
   // forking.
   void Run(bool run_as_daemon);
 
  private:
   friend class MetricsDaemonTest;
-  FRIEND_TEST(MetricsDaemonTest, LogDailyUseRecordBadFileLocation);
-  FRIEND_TEST(MetricsDaemonTest, LogDailyUseRecordOnLogin);
-  FRIEND_TEST(MetricsDaemonTest, LogDailyUseRecordRoundDown);
-  FRIEND_TEST(MetricsDaemonTest, LogDailyUseRecordRoundUp);
+  FRIEND_TEST(MetricsDaemonTest, DailyUseReporter);
   FRIEND_TEST(MetricsDaemonTest, LookupNetworkState);
   FRIEND_TEST(MetricsDaemonTest, LookupPowerState);
   FRIEND_TEST(MetricsDaemonTest, LookupScreenSaverState);
   FRIEND_TEST(MetricsDaemonTest, LookupSessionState);
   FRIEND_TEST(MetricsDaemonTest, MessageFilter);
   FRIEND_TEST(MetricsDaemonTest, NetStateChangedSimpleDrop);
   FRIEND_TEST(MetricsDaemonTest, NetStateChangedSuspend);
   FRIEND_TEST(MetricsDaemonTest, PowerStateChanged);
   FRIEND_TEST(MetricsDaemonTest, ScreenSaverStateChanged);
   FRIEND_TEST(MetricsDaemonTest, SendMetric);
   FRIEND_TEST(MetricsDaemonTest, SessionStateChanged);
-  FRIEND_TEST(MetricsDaemonTest, SetUserActiveStateSendOnLogin);
-  FRIEND_TEST(MetricsDaemonTest, SetUserActiveStateSendOnMonitor);
+  FRIEND_TEST(MetricsDaemonTest, SetUserActiveState);
   FRIEND_TEST(MetricsDaemonTest, SetUserActiveStateTimeJump);
 
   // The network states (see network_states.h).
   enum NetworkState {
     kUnknownNetworkState = -1, // Initial/unknown network state.
 #define STATE(name, capname) kNetworkState ## capname,
 #include "network_states.h"
     kNumberNetworkStates
   };
 
@@ skipping 105 matching lines @@
 
   // Unschedules a scheduled use monitor, if any.
   void UnscheduleUseMonitor();
 
   // Sends a regular (exponential) histogram sample to Chrome for
   // transport to UMA. See MetricsLibrary::SendToUMA in
   // metrics_library.h for a description of the arguments.
   void SendMetric(const std::string& name, int sample,
                   int min, int max, int nbuckets);
 
+  static void DailyUseReporter(void* data, int tag, int count);
+
   // Test mode.
   bool testing_;
 
   // The metrics library handle.
   MetricsLibraryInterface* metrics_lib_;
 
-  const char* daily_use_record_file_;
-
   // Current network state.
   NetworkState network_state_;
 
   // Timestamps last network state update.  This timestamp is used to
   // sample the time from the network going online to going offline so
   // TimeTicks ensures a monotonically increasing TimeDelta.
   base::TimeTicks network_state_last_;
 
   // Current power state.
   PowerState power_state_;
 
   // Current user session state.
   SessionState session_state_;
 
   // Is the user currently active: power is on, user session has
   // started, screen is not locked.
   bool user_active_;
 
   // Timestamps last user active update.  Active use time is
   // aggregated each day before sending to UMA so using time since the
   // epoch as the timestamp.
   base::Time user_active_last_;
 
-  // Last stored daily use day (since the epoch).
-  int daily_use_day_last_;
+  scoped_ptr<chromeos_metrics::TaggedCounterInterface> daily_use_;
 
   // Sleep period until the next daily usage aggregation performed by
   // the daily use monitor (see ScheduleUseMonitor).
   int usemon_interval_;
 
   // Scheduled daily use monitor source (see ScheduleUseMonitor).
   GSource* usemon_source_;
 };
 
 #endif  // METRICS_DAEMON_H_