109 lines
3.5 KiB
C
109 lines
3.5 KiB
C
|
// Copyright 2014 The Chromium Authors
|
||
|
|
// Use of this source code is governed by a BSD-style license that can be
|
||
|
|
// found in the LICENSE file.
|
||
|
|
|
||
|
|
#ifndef COMPONENTS_METRICS_DAILY_EVENT_H_
|
||
|
|
#define COMPONENTS_METRICS_DAILY_EVENT_H_
|
||
|
|
|
||
|
|
#include <memory>
|
||
|
|
#include <string>
|
||
|
|
#include <vector>
|
||
|
|
|
||
|
|
#include "base/memory/raw_ptr.h"
|
||
|
|
#include "base/time/time.h"
|
||
|
|
|
||
|
|
class PrefRegistrySimple;
|
||
|
|
class PrefService;
|
||
|
|
|
||
|
|
namespace metrics {
|
||
|
|
|
||
|
|
// DailyEvent is used for throttling an event to about once per day, even if
|
||
|
|
// the program is restarted more frequently. It is based on local machine
|
||
|
|
// time, so it could be fired more often if the clock is changed.
|
||
|
|
//
|
||
|
|
// The service using the DailyEvent should first provide all of the Observers
|
||
|
|
// for the interval, and then arrange for CheckInterval() to be called
|
||
|
|
// periodically to test if the event should be fired.
|
||
|
|
class DailyEvent {
|
||
|
|
public:
|
||
|
|
// Different reasons that Observer::OnDailyEvent() is called.
|
||
|
|
// This enum is used for histograms and must not be renumbered.
|
||
|
|
enum class IntervalType {
|
||
|
|
FIRST_RUN,
|
||
|
|
DAY_ELAPSED,
|
||
|
|
CLOCK_CHANGED,
|
||
|
|
kMaxValue = CLOCK_CHANGED,
|
||
|
|
};
|
||
|
|
|
||
|
|
// Observer receives notifications from a DailyEvent.
|
||
|
|
// Observers must be added before the DailyEvent begins checking time,
|
||
|
|
// and will be owned by the DailyEvent.
|
||
|
|
class Observer {
|
||
|
|
public:
|
||
|
|
Observer();
|
||
|
|
|
||
|
|
Observer(const Observer&) = delete;
|
||
|
|
Observer& operator=(const Observer&) = delete;
|
||
|
|
|
||
|
|
virtual ~Observer();
|
||
|
|
|
||
|
|
// Called when the daily event is fired.
|
||
|
|
virtual void OnDailyEvent(IntervalType type) = 0;
|
||
|
|
};
|
||
|
|
|
||
|
|
// Constructs DailyEvent monitor which stores the time it last fired in the
|
||
|
|
// preference |pref_name|. |pref_name| should be registered by calling
|
||
|
|
// RegisterPref before using this object.
|
||
|
|
// Caller is responsible for ensuring that |pref_service| and |pref_name|
|
||
|
|
// outlive the DailyEvent.
|
||
|
|
// |histogram_name| is the name of the UMA metric which record when this
|
||
|
|
// interval fires, and should be registered in histograms.xml. If
|
||
|
|
// |histogram_name| is empty - interval fires are not recorded.
|
||
|
|
DailyEvent(PrefService* pref_service,
|
||
|
|
const char* pref_name,
|
||
|
|
const std::string& histogram_name);
|
||
|
|
|
||
|
|
DailyEvent(const DailyEvent&) = delete;
|
||
|
|
DailyEvent& operator=(const DailyEvent&) = delete;
|
||
|
|
|
||
|
|
~DailyEvent();
|
||
|
|
|
||
|
|
// Adds a observer to be notified when a day elapses. All observers should
|
||
|
|
// be registered before the the DailyEvent starts checking time.
|
||
|
|
void AddObserver(std::unique_ptr<Observer> observer);
|
||
|
|
|
||
|
|
// Checks if a day has elapsed. If it has, OnDailyEvent will be called on
|
||
|
|
// all observers.
|
||
|
|
void CheckInterval();
|
||
|
|
|
||
|
|
// Registers the preference used by this interval.
|
||
|
|
static void RegisterPref(PrefRegistrySimple* registry,
|
||
|
|
const std::string& pref_name);
|
||
|
|
|
||
|
|
private:
|
||
|
|
// Handles an interval elapsing because of |type|.
|
||
|
|
void OnInterval(base::Time now, IntervalType type);
|
||
|
|
|
||
|
|
// A weak pointer to the PrefService object to read and write preferences
|
||
|
|
// from. Calling code should ensure this object continues to exist for the
|
||
|
|
// lifetime of the DailyEvent object.
|
||
|
|
raw_ptr<PrefService> pref_service_;
|
||
|
|
|
||
|
|
// The name of the preference to store the last fired time in.
|
||
|
|
// Calling code should ensure this outlives the DailyEvent.
|
||
|
|
const char* pref_name_;
|
||
|
|
|
||
|
|
// The name of the histogram to record intervals.
|
||
|
|
std::string histogram_name_;
|
||
|
|
|
||
|
|
// A list of observers.
|
||
|
|
std::vector<std::unique_ptr<Observer>> observers_;
|
||
|
|
|
||
|
|
// The time that the daily event was last fired.
|
||
|
|
base::Time last_fired_;
|
||
|
|
};
|
||
|
|
|
||
|
|
} // namespace metrics
|
||
|
|
|
||
|
|
#endif // COMPONENTS_METRICS_DAILY_EVENT_H_
|