blob: 907288b59f85a2d8e5969e09ae17580d87429178 [file] [log] [blame]
// Copyright 2019 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/callback_list.h"
#include "base/memory/scoped_refptr.h"
#include "base/no_destructor.h"
#include "base/observer_list.h"
#include "base/observer_list_types.h"
#include "base/sequenced_task_runner.h"
namespace base {
class FilePath;
namespace metrics {
namespace structured {
class EventBase;
// Recorder is a singleton to help communicate with the
// StructuredMetricsProvider. It serves two purposes:
// 1. Begin the initialization of the StructuredMetricsProvider (see class
// comment for more details).
// 2. Add an event for the StructuredMetricsProvider to record.
// The StructuredMetricsProvider is owned by the MetricsService, but it needs to
// be accessible to any part of the codebase, via an EventBase subclass, to
// record events. The StructuredMetricsProvider registers itself as an observer
// of this singleton when recording is enabled, and calls to Record (for
// recording) or ProfileAdded (for initialization) are then forwarded to it.
class Recorder {
class Observer : public base::CheckedObserver {
// Called on a call to Record.
virtual void OnRecord(const EventBase& event) = 0;
// Called on a call to ProfileAdded.
virtual void OnProfileAdded(const base::FilePath& profile_path) = 0;
static Recorder* GetInstance();
// Notifies observers of |event|,
void Record(const EventBase& event);
// Notifies the StructuredMetricsProvider that a profile has been added with
// path |profile_path|. The first call to ProfileAdded initializes the
// provider using the keys stored in |profile_path|, so care should be taken
// to ensure the first call provides a |profile_path| suitable for metrics
// collection.
// TODO( When structured metrics expands beyond Chrome OS,
// investigate whether initialization can be simplified for Chrome.
void ProfileAdded(const base::FilePath& profile_path);
void SetUiTaskRunner(
const scoped_refptr<base::SequencedTaskRunner> ui_task_runner);
friend class base::NoDestructor<Recorder>;
friend class StructuredMetricsProvider;
Recorder(const Recorder&) = delete;
Recorder& operator=(const Recorder&) = delete;
void AddObserver(Observer* observer);
void RemoveObserver(Observer* observer);
scoped_refptr<base::SequencedTaskRunner> ui_task_runner_;
base::ObserverList<Observer> observers_;
} // namespace structured
} // namespace metrics