// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef ANDROID_WEBVIEW_BROWSER_METRICS_AW_METRICS_SERVICE_CLIENT_H_
#define ANDROID_WEBVIEW_BROWSER_METRICS_AW_METRICS_SERVICE_CLIENT_H_
#include <memory>
#include <string>
#include "android_webview/browser/lifecycle/webview_app_state_observer.h"
#include "base/metrics/field_trial.h"
#include "base/no_destructor.h"
#include "base/sequence_checker.h"
#include "base/time/time.h"
#include "components/embedder_support/android/metrics/android_metrics_service_client.h"
#include "components/metrics/enabled_state_provider.h"
#include "components/metrics/metrics_log_uploader.h"
#include "components/metrics/metrics_service_client.h"
namespace android_webview {
// These values are persisted to logs. Entries should not be renumbered and
// numeric values should never be reused.
// TODO(crbug.com/40651974): remove this when the kInstallDate pref has
// been persisted for one or two milestones. Visible for testing.
enum class BackfillInstallDate {
kValidInstallDatePref = 0,
kCouldNotGetPackageManagerInstallDate = 1,
kPersistedPackageManagerInstallDate = 2,
kMaxValue = kPersistedPackageManagerInstallDate,
};
// The amount of delay before calculating and recording the app data directory
// size, intended for avoiding IO contention when an app is initializing.
//
// Visible for testing.
extern const base::TimeDelta kRecordAppDataDirectorySizeDelay;
// AwMetricsServiceClient is a singleton which manages WebView metrics
// collection.
//
// Metrics should be enabled iff all these conditions are met:
// - The user has not opted out (controlled by GMS).
// - The app has not opted out (controlled by manifest tag).
// - This client is in the 2% sample (controlled by client ID hash).
// The first two are recorded in |user_consent_| and |app_consent_|, which are
// set by SetHaveMetricsConsent(). The last is recorded in |is_in_sample_|.
//
// Metrics are pseudonymously identified by a randomly-generated "client ID".
// WebView stores this in prefs, written to the app's data directory. There's a
// different such directory for each user, for each app, on each device. So the
// ID should be unique per (device, app, user) tuple.
//
// To avoid the appearance that we're doing anything sneaky, the client ID
// should only be created and retained when neither the user nor the app have
// opted out. Otherwise, the presence of the ID could give the impression that
// metrics were being collected.
//
// WebView metrics set up happens like so:
//
// startup
// │
// ├────────────┐
// │ ▼
// │ query GMS for consent
// ▼ │
// Initialize() │
// │ ▼
// │ SetHaveMetricsConsent()
// │ │
// │ ┌──────────┘
// ▼ ▼
// MaybeStartMetrics()
// │
// ▼
// MetricsService::Start()
//
// All the named functions in this diagram happen on the UI thread. Querying GMS
// happens in the background, and the result is posted back to the UI thread, to
// SetHaveMetricsConsent(). Querying GMS is slow, so SetHaveMetricsConsent()
// typically happens after Initialize(), but it may happen before.
//
// Each path sets a flag, |init_finished_| or |set_consent_finished_|, to show
// that path has finished, and then calls MaybeStartMetrics(). When
// MaybeStartMetrics() is called the first time, it sees only one flag is true,
// and does nothing. When MaybeStartMetrics() is called the second time, it
// decides whether to start metrics.
//
// If consent was granted, MaybeStartMetrics() determines sampling by hashing
// the client ID (generating a new ID if there was none). If this client is in
// the sample, it then calls MetricsService::Start(). If consent was not
// granted, MaybeStartMetrics() instead clears the client ID, if any.
class AwMetricsServiceClient : public ::metrics::AndroidMetricsServiceClient,
public WebViewAppStateObserver {
friend class base::NoDestructor<AwMetricsServiceClient>;
public:
// This interface define the tasks that depend on the
// android_webview/browser directory.
class Delegate {
public:
Delegate();
virtual ~Delegate();
// Not copyable or movable
Delegate(const Delegate&) = delete;
Delegate& operator=(const Delegate&) = delete;
Delegate(Delegate&&) = delete;
Delegate& operator=(Delegate&&) = delete;
virtual void RegisterAdditionalMetricsProviders(
metrics::MetricsService* service) = 0;
virtual void AddWebViewAppStateObserver(
WebViewAppStateObserver* observer) = 0;
virtual bool HasAwContentsEverCreated() const = 0;
};
static AwMetricsServiceClient* GetInstance();
static void SetInstance(
std::unique_ptr<AwMetricsServiceClient> aw_metrics_service_client);
static void RegisterMetricsPrefs(PrefRegistrySimple* registry);
explicit AwMetricsServiceClient(std::unique_ptr<Delegate> delegate);
AwMetricsServiceClient(const AwMetricsServiceClient&) = delete;
AwMetricsServiceClient& operator=(const AwMetricsServiceClient&) = delete;
~AwMetricsServiceClient() override;
// metrics::MetricsServiceClient
int32_t GetProduct() override;
// WebViewAppStateObserver
void OnAppStateChanged(WebViewAppStateObserver::State state) override;
// metrics::AndroidMetricsServiceClient:
void OnMetricsStart() override;
void OnMetricsNotStarted() override;
int GetSampleRatePerMille() const override;
int GetPackageNameLimitRatePerMille() override;
void RegisterAdditionalMetricsProviders(
metrics::MetricsService* service) override;
// Gets the embedding app's package name if it's OK to log. Otherwise, this
// returns the empty string.
std::string GetAppPackageNameIfLoggable() override;
// Always returns `true`, indicating to record the package name
bool ShouldRecordPackageName() override;
// - return `true` if client used to be sampled out.
// - return `false` if client used to be in-sampled.
virtual bool ShouldApplyMetricsFiltering() const;
protected:
// Restrict usage of the inherited AndroidMetricsServiceClient::RegisterPrefs,
// RegisterMetricsPrefs should be used instead.
using AndroidMetricsServiceClient::RegisterPrefs;
private:
bool app_in_foreground_ = false;
base::Time time_created_;
std::unique_ptr<Delegate> delegate_;
};
} // namespace android_webview
#endif // ANDROID_WEBVIEW_BROWSER_METRICS_AW_METRICS_SERVICE_CLIENT_H_
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