android_webview/browser/metrics/aw_metrics_service_client.h - chromium/src - Git at Google

 // 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 "android_webview/common/metrics/app_package_name_logging_rule.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 {

 namespace prefs {
 extern const char kMetricsAppPackageNameLoggingRule[];
 extern const char kAppPackageNameLoggingRuleLastUpdateTime[];
 }  // namespace prefs

 // These values are persisted to logs. Entries should not be renumbered and
 // numeric values should never be reused.
 // TODO(https://crbug.com/1012025): 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.
 //
 // Similarly, when
 // `android_webview::features::kWebViewAppsPackageNamesAllowlist` is enabled,
 // WebView will try to lookup the embedding app's package name in a list of apps
 // whose package names are allowed to be recorded. This operation takes place on
 // a background thread. The result of the lookup is then posted back on the UI
 // thread and SetAppPackageNameLoggingRule() will be called. Unlike user's
 // consent, the metrics service doesn't currently block on the allowlist lookup
 // result. If the result isn't present at the moment of creating a metrics log,
 // it assumes that the app package name isn't allowed to be logged.

 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;
   };

   // An enum to track the status of AppPackageNameLoggingRule used in
   // ShouldRecordPackageName. These values are persisted to logs. Entries should
   // not be renumbered and numeric values should never be reused.
   enum class AppPackageNameLoggingRuleStatus {
     kNotLoadedNoCache = 0,
     kNotLoadedUseCache = 1,
     kNewVersionFailedNoCache = 2,
     kNewVersionFailedUseCache = 3,
     kNewVersionLoaded = 4,
     kSameVersionAsCache = 5,
     kMaxValue = kSameVersionAsCache,
   };

   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;

   // If `android_webview::features::kWebViewAppsPackageNamesAllowlist` is
   // enabled:
   // - It returns `true` if the app is in the list of allowed apps.
   // - It returns `false` if the app isn't in the allowlist or if the lookup
   //   operation fails or hasn't finished yet.
   //
   // If the feature isn't enabled, the default sampling behaviour in
   // `::metrics::AndroidMetricsServiceClient::ShouldRecordPackageName` is used.
   bool ShouldRecordPackageName() override;

   // Sets that the embedding app's package name is allowed to be recorded in
   // UMA logs. This is determened by looking up the app package name in a
   // dynamically downloaded allowlist of apps see
   // `AwAppsPackageNamesAllowlistComponentLoaderPolicy`.
   //
   // `record` If it has a null value, then it will be ignored and the cached
   //          record will be used if any.
   void SetAppPackageNameLoggingRule(
       absl::optional<AppPackageNameLoggingRule> record);

   // Get the cached record of the app package names allowlist set by
   // `SetAppPackageNameLoggingRule` if any.
   absl::optional<AppPackageNameLoggingRule>
   GetCachedAppPackageNameLoggingRule();

   // The last time the apps package name allowlist was queried from the
   // component update service, regardless if it was successful or not.
   base::Time GetAppPackageNameLoggingRuleLastUpdateTime() const;
   void SetAppPackageNameLoggingRuleLastUpdateTime(base::Time update_time);

   // If `android_webview::features::kWebViewMetricsFiltering` is
   // enabled:
   // - return `true` if client used to be sampled out.
   // - return `false` if client used to be in-sampled.
   //
   // If the feature isn't enabled, return false.
   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_;

   absl::optional<AppPackageNameLoggingRule> cached_package_name_record_;
   AppPackageNameLoggingRuleStatus package_name_record_status_ =
       AppPackageNameLoggingRuleStatus::kNotLoadedNoCache;
 };

 }  // namespace android_webview

 #endif  // ANDROID_WEBVIEW_BROWSER_METRICS_AW_METRICS_SERVICE_CLIENT_H_
	// 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 "android_webview/common/metrics/app_package_name_logging_rule.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 {

	namespace prefs {
	extern const char kMetricsAppPackageNameLoggingRule[];
	extern const char kAppPackageNameLoggingRuleLastUpdateTime[];
	} // namespace prefs

	// These values are persisted to logs. Entries should not be renumbered and
	// numeric values should never be reused.
	// TODO(https://crbug.com/1012025): 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.
	//
	// Similarly, when
	// `android_webview::features::kWebViewAppsPackageNamesAllowlist` is enabled,
	// WebView will try to lookup the embedding app's package name in a list of apps
	// whose package names are allowed to be recorded. This operation takes place on
	// a background thread. The result of the lookup is then posted back on the UI
	// thread and SetAppPackageNameLoggingRule() will be called. Unlike user's
	// consent, the metrics service doesn't currently block on the allowlist lookup
	// result. If the result isn't present at the moment of creating a metrics log,
	// it assumes that the app package name isn't allowed to be logged.

	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;
	};

	// An enum to track the status of AppPackageNameLoggingRule used in
	// ShouldRecordPackageName. These values are persisted to logs. Entries should
	// not be renumbered and numeric values should never be reused.
	enum class AppPackageNameLoggingRuleStatus {
	kNotLoadedNoCache = 0,
	kNotLoadedUseCache = 1,
	kNewVersionFailedNoCache = 2,
	kNewVersionFailedUseCache = 3,
	kNewVersionLoaded = 4,
	kSameVersionAsCache = 5,
	kMaxValue = kSameVersionAsCache,
	};

	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;

	// If `android_webview::features::kWebViewAppsPackageNamesAllowlist` is
	// enabled:
	// - It returns `true` if the app is in the list of allowed apps.
	// - It returns `false` if the app isn't in the allowlist or if the lookup
	// operation fails or hasn't finished yet.
	//
	// If the feature isn't enabled, the default sampling behaviour in
	// `::metrics::AndroidMetricsServiceClient::ShouldRecordPackageName` is used.
	bool ShouldRecordPackageName() override;

	// Sets that the embedding app's package name is allowed to be recorded in
	// UMA logs. This is determened by looking up the app package name in a
	// dynamically downloaded allowlist of apps see
	// `AwAppsPackageNamesAllowlistComponentLoaderPolicy`.
	//
	// `record` If it has a null value, then it will be ignored and the cached
	// record will be used if any.
	void SetAppPackageNameLoggingRule(
	absl::optional<AppPackageNameLoggingRule> record);

	// Get the cached record of the app package names allowlist set by
	// `SetAppPackageNameLoggingRule` if any.
	absl::optional<AppPackageNameLoggingRule>
	GetCachedAppPackageNameLoggingRule();

	// The last time the apps package name allowlist was queried from the
	// component update service, regardless if it was successful or not.
	base::Time GetAppPackageNameLoggingRuleLastUpdateTime() const;
	void SetAppPackageNameLoggingRuleLastUpdateTime(base::Time update_time);

	// If `android_webview::features::kWebViewMetricsFiltering` is
	// enabled:
	// - return `true` if client used to be sampled out.
	// - return `false` if client used to be in-sampled.
	//
	// If the feature isn't enabled, return false.
	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_;

	absl::optional<AppPackageNameLoggingRule> cached_package_name_record_;
	AppPackageNameLoggingRuleStatus package_name_record_status_ =
	AppPackageNameLoggingRuleStatus::kNotLoadedNoCache;
	};

	} // namespace android_webview

	#endif // ANDROID_WEBVIEW_BROWSER_METRICS_AW_METRICS_SERVICE_CLIENT_H_