1 // Copyright 2019 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef COMPONENTS_METRICS_DEMOGRAPHICS_USER_DEMOGRAPHICS_H_
6 #define COMPONENTS_METRICS_DEMOGRAPHICS_USER_DEMOGRAPHICS_H_
7 
8 #include "base/time/time.h"
9 #include "third_party/metrics_proto/user_demographics.pb.h"
10 
11 class PrefService;
12 
13 namespace user_prefs {
14 class PrefRegistrySyncable;
15 }  // namespace user_prefs
16 
17 namespace metrics {
18 
19 // Default value for user gender when no value has been set.
20 constexpr int kUserDemographicsGenderDefaultValue = -1;
21 
22 // Default value for user gender enum when no value has been set.
23 constexpr UserDemographicsProto_Gender kUserDemographicGenderDefaultEnumValue =
24     UserDemographicsProto_Gender_Gender_MIN;
25 
26 // Default value for user gender when no value has been set.
27 constexpr int kUserDemographicsBirthYearDefaultValue = -1;
28 
29 // Default value for birth year offset when no value has been set. Set to a
30 // really high value that |kUserDemographicsBirthYearNoiseOffsetRange| will
31 // never go over.
32 constexpr int kUserDemographicsBirthYearNoiseOffsetDefaultValue = 100;
33 
34 // Boundary of the +/- range in years within witch to randomly pick an offset to
35 // add to the user birth year. This adds noise to the birth year to not allow
36 // someone to accurately know a user's age. Possible offsets range from -2 to 2.
37 constexpr int kUserDemographicsBirthYearNoiseOffsetRange = 2;
38 
39 // Minimal user age in years to provide demographics for.
40 constexpr int kUserDemographicsMinAgeInYears = 20;
41 
42 // Max user age to provide demopgrahics for.
43 constexpr int kUserDemographicsMaxAgeInYears = 85;
44 
45 // Syncable preference names, exposed publicly for testing.
46 extern const char kSyncDemographicsPrefName[];
47 extern const char kSyncDemographicsBirthYearOffsetPrefName[];
48 
49 // These are not prefs, they are paths inside of kSyncDemographics.
50 extern const char kSyncDemographicsBirthYearPath[];
51 extern const char kSyncDemographicsGenderPath[];
52 
53 // Container of user demographics.
54 struct UserDemographics {
55   int birth_year = 0;
56   UserDemographicsProto_Gender gender = UserDemographicsProto::Gender_MIN;
57 };
58 
59 // Represents the status of providing user demographics (noised birth year and
60 // gender) that are logged to UMA. Entries of the enum should not be renumbered
61 // and numeric values should never be reused. Please keep in sync with
62 // "UserDemographicsStatus" in src/tools/metrics/histograms/enums.xml.  There
63 // should only be one entry representing demographic data that is ineligible to
64 // be provided. A finer grained division of kIneligibleDemographicsData (e.g.,
65 // INVALID_BIRTH_YEAR) might help inferring categories of demographics that
66 // should not be exposed to protect privacy.
67 enum class UserDemographicsStatus {
68   // Could get the user's noised birth year and gender.
69   kSuccess = 0,
70   // Sync is not enabled.
71   kSyncNotEnabled = 1,
72   // User's birth year and gender are ineligible to be provided either because
73   // some of them don't exist (missing data) or some of them are not eligible to
74   // be provided.
75   kIneligibleDemographicsData = 2,
76   // Could not get the time needed to compute the user's age.
77   kCannotGetTime = 3,
78   // There is more than one Profile for the Chrome browser. This entry is used
79   // by the DemographicMetricsProvider client.
80   kMoreThanOneProfile = 4,
81   // There is no sync service available for the loaded Profile. This entry is
82   // used by the DemographicMetricsProvider client.
83   kNoSyncService = 5,
84   // Upper boundary of the enum that is needed for the histogram.
85   kMaxValue = kNoSyncService
86 };
87 
88 // Container and handler for data related to the retrieval of user demographics.
89 // Holds either valid demographics data or an error code.
90 class UserDemographicsResult {
91  public:
92   // Builds a UserDemographicsResult that contains user demographics and has a
93   // UserDemographicsStatus::kSuccess status.
94   static UserDemographicsResult ForValue(UserDemographics value);
95 
96   // Builds a UserDemographicsResult that does not have user demographics (only
97   // default values) and has a status other than
98   // UserDemographicsStatus::kSuccess.
99   static UserDemographicsResult ForStatus(UserDemographicsStatus status);
100 
101   // Determines whether demographics could be successfully retrieved.
102   bool IsSuccess() const;
103 
104   // Gets the status of the result.
105   UserDemographicsStatus status() const;
106 
107   // Gets the value of the result which will contain data when status() is
108   // UserDemographicsStatus::kSuccess.
109   const UserDemographics& value() const;
110 
111  private:
112   UserDemographicsResult(UserDemographics value, UserDemographicsStatus status);
113 
114   UserDemographics value_;
115   UserDemographicsStatus status_ = UserDemographicsStatus::kMaxValue;
116 };
117 
118 // Registers the profile preferences that are needed to persist demographics
119 // information exposed via GetUserNoisedBirthYearAndGenderFromPrefs().
120 void RegisterDemographicsProfilePrefs(
121     user_prefs::PrefRegistrySyncable* registry);
122 
123 // Clears the profile's demographics-related preferences containing user data.
124 // This excludes the internal bith year offset.
125 void ClearDemographicsPrefs(PrefService* pref_service);
126 
127 // Gets the synced user’s noised birth year and gender from preferences, see doc
128 // of metrics::DemographicMetricsProvider in
129 // components/metrics/demographic_metrics_provider.h for more details. Returns
130 // an error status with an empty value when the user's birth year or gender
131 // cannot be provided. You need to provide an accurate |now| time that
132 // represents the current time.
133 UserDemographicsResult GetUserNoisedBirthYearAndGenderFromPrefs(
134     base::Time now,
135     PrefService* pref_service);
136 
137 }  // namespace metrics
138 
139 #endif  // COMPONENTS_METRICS_DEMOGRAPHICS_USER_DEMOGRAPHICS_H_
140