components/rappor/rappor_service.h

   1 // Copyright 2014 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_RAPPOR_RAPPOR_SERVICE_H_
   6 #define COMPONENTS_RAPPOR_RAPPOR_SERVICE_H_
   7
   8 #include <map>
   9 #include <string>
  10
  11 #include "base/basictypes.h"
  12 #include "base/macros.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/timer/timer.h"
  15 #include "components/metrics/daily_event.h"
  16 #include "components/rappor/rappor_parameters.h"
  17
  18 class PrefRegistrySimple;
  19 class PrefService;
  20
  21 namespace net {
  22 class URLRequestContextGetter;
  23 }
  24
  25 namespace rappor {
  26
  27 class LogUploader;
  28 class RapporMetric;
  29 class RapporReports;
  30
  31 // The type of data stored in a metric.
  32 enum RapporType {
  33   // For sampling the eTLD+1 of a URL.
  34   ETLD_PLUS_ONE_RAPPOR_TYPE = 0,
  35   COARSE_RAPPOR_TYPE,
  36   NUM_RAPPOR_TYPES
  37 };
  38
  39 // This class provides an interface for recording samples for rappor metrics,
  40 // and periodically generates and uploads reports based on the collected data.
  41 class RapporService {
  42  public:
  43   // Constructs a RapporService.
  44   // Calling code is responsible for ensuring that the lifetime of
  45   // |pref_service| is longer than the lifetime of RapporService.
  46   explicit RapporService(PrefService* pref_service);
  47   virtual ~RapporService();
  48
  49   // Add an observer for collecting daily metrics.
  50   void AddDailyObserver(scoped_ptr<metrics::DailyEvent::Observer> observer);
  51
  52   // Starts the periodic generation of reports and upload attempts.
  53   // |metrics enabled| should be true if UMA users have opted in.
  54   void Start(net::URLRequestContextGetter* context,
  55              bool metrics_enabled);
  56
  57   // Records a sample of the rappor metric specified by |metric_name|.
  58   // Creates and initializes the metric, if it doesn't yet exist.
  59   void RecordSample(const std::string& metric_name,
  60                     RapporType type,
  61                     const std::string& sample);
  62
  63   // Registers the names of all of the preferences used by RapporService in the
  64   // provided PrefRegistry. This should be called before calling Start().
  65   static void RegisterPrefs(PrefRegistrySimple* registry);
  66
  67  protected:
  68   // Initializes the state of the RapporService.
  69   void Initialize(int32_t cohort,
  70                   const std::string& secret,
  71                   const ReportingLevel& reporting_level);
  72
  73   // Retrieves the cohort number this client was assigned to, generating it if
  74   // doesn't already exist. The cohort should be persistent.
  75   int32_t LoadCohort();
  76
  77   // Retrieves the value for secret_ from preferences, generating it if doesn't
  78   // already exist. The secret should be persistent, so that additional bits
  79   // from the client do not get exposed over time.
  80   std::string LoadSecret();
  81
  82   // Logs all of the collected metrics to the reports proto message and clears
  83   // the internal map. Exposed for tests. Returns true if any metrics were
  84   // recorded.
  85   bool ExportMetrics(RapporReports* reports);
  86
  87   // Records a sample of the rappor metric specified by |parameters|.
  88   // Creates and initializes the metric, if it doesn't yet exist.
  89   // Exposed for tests.
  90   void RecordSampleInternal(const std::string& metric_name,
  91                             const RapporParameters& parameters,
  92                             const std::string& sample);
  93
  94  private:
  95   // Check if the service has been started successfully.
  96   bool IsInitialized() const;
  97
  98   // Called whenever the logging interval elapses to generate a new log of
  99   // reports and pass it to the uploader.
 100   void OnLogInterval();
 101
 102   // Finds a metric in the metrics_map_, creating it if it doesn't already
 103   // exist.
 104   RapporMetric* LookUpMetric(const std::string& metric_name,
 105                              const RapporParameters& parameters);
 106
 107   // A weak pointer to the PrefService used to read and write preferences.
 108   PrefService* pref_service_;
 109
 110   // Client-side secret used to generate fake bits.
 111   std::string secret_;
 112
 113   // The cohort this client is assigned to. -1 is uninitialized.
 114   int32_t cohort_;
 115
 116   // Timer which schedules calls to OnLogInterval().
 117   base::OneShotTimer<RapporService> log_rotation_timer_;
 118
 119   // A daily event for collecting metrics once a day.
 120   metrics::DailyEvent daily_event_;
 121
 122   // A private LogUploader instance for sending reports to the server.
 123   scoped_ptr<LogUploader> uploader_;
 124
 125   // What reporting level of metrics are being reported.
 126   ReportingLevel reporting_level_;
 127
 128   // We keep all registered metrics in a map, from name to metric.
 129   // The map owns the metrics it contains.
 130   std::map<std::string, RapporMetric*> metrics_map_;
 131
 132   DISALLOW_COPY_AND_ASSIGN(RapporService);
 133 };
 134
 135 }  // namespace rappor
 136
 137 #endif  // COMPONENTS_RAPPOR_RAPPOR_SERVICE_H_