blob: 317e64e76934e71e7e153286b348cee103fbafaf [file] [log] [blame]
// Copyright 2018 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.
#include <memory>
#include "base/memory/scoped_refptr.h"
#include "base/single_thread_task_runner.h"
#include "base/task/cancelable_task_tracker.h"
#include "base/time/clock.h"
#include "base/time/default_clock.h"
#include "base/timer/timer.h"
#include "components/history/core/browser/history_service.h"
#include "components/keyed_service/core/keyed_service.h"
#include "components/prefs/pref_registry_simple.h"
#include "components/prefs/pref_service.h"
// Emits domain mixing metrics based on the Google search activity of the user.
// The implementation schedules repeating tasks to compute the metrics when
// needed (at most once every day). The metrics are computed in the background
// and their computation is delayed at least a couple of seconds after the
// emitter is created to ensure browser startup performance is not affected.
// See for more details on
// what domain mixing metrics are and how they are computed.
class GoogleSearchDomainMixingMetricsEmitter : public KeyedService {
// Preference field holding the last time at which domain mixing metrics for
// Google searches were computed, as a base::Time object. See
// for more details on what
// domain mixing metrics are and how they are computed.
static const char kLastMetricsTime[];
PrefService* prefs,
history::HistoryService* history_service);
~GoogleSearchDomainMixingMetricsEmitter() override;
// Registers the preference fields used for computing Google search domain
// mixing metrics.
static void RegisterProfilePrefs(PrefRegistrySimple* registry);
// Starts the emitter. The implementation will schedule a background task to
// run the next time domain mixing metrics will need to be computed, and at
// least a few seconds after Start() is called if metrics need to be computed
// now. This delay is meant to ensure that browser startup performance is not
// affected.
void Start();
// Overrides the default clock for testing purposes.
void SetClockForTesting(std::unique_ptr<base::Clock> clock);
// Overrides the default timer for testing purposes.
void SetTimerForTesting(std::unique_ptr<base::RepeatingTimer> timer);
// Overrides the UI thread task runner for testing purposes.
void SetUIThreadTaskRunnerForTesting(
scoped_refptr<base::SingleThreadTaskRunner> ui_thread_task_runner);
// Emits metrics for active days since the last one for which metrics were
// computed.
void EmitMetrics();
// KeyedService:
void Shutdown() override;
PrefService* const prefs_; // Not owned.
history::HistoryService* const history_service_; // Not owned.
std::unique_ptr<base::Clock> clock_ = std::make_unique<base::DefaultClock>();
// Timer used to compute domain mixing metrics daily if the emitter is
// long-lived.
std::unique_ptr<base::RepeatingTimer> timer_ =
base::CancelableTaskTracker task_tracker_;
scoped_refptr<base::SingleThreadTaskRunner> ui_thread_task_runner_;