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
  17 class PrefRegistrySimple;
  18 class PrefService;
  19
  20 namespace net {
  21 class URLRequestContextGetter;
  22 }
  23
  24 namespace rappor {
  25
  26 class LogUploader;
  27 class RapporMetric;
  28 class RapporReports;
  29 struct RapporParameters;
  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   NUM_RAPPOR_TYPES
  36 };
  37
  38 // This class provides an interface for recording samples for rappor metrics,
  39 // and periodically generates and uploads reports based on the collected data.
  40 class RapporService {
  41  public:
  42   // Constructs a RapporService.
  43   // Calling code is responsible for ensuring that the lifetime of
  44   // |pref_service| is longer than the lifetime of RapporService.
  45   explicit RapporService(PrefService* pref_service);
  46   virtual ~RapporService();
  47
  48   // Add an observer for collecting daily metrics.
  49   void AddDailyObserver(scoped_ptr<metrics::DailyEvent::Observer> observer);
  50
  51   // Starts the periodic generation of reports and upload attempts.
  52   void Start(net::URLRequestContextGetter* context,
  53              bool metrics_enabled);
  54
  55   // Records a sample of the rappor metric specified by |metric_name|.
  56   // Creates and initializes the metric, if it doesn't yet exist.
  57   void RecordSample(const std::string& metric_name,
  58                     RapporType type,
  59                     const std::string& sample);
  60
  61   // Sets the cohort value. For use by tests only.
  62   void SetCohortForTesting(uint32_t cohort) { cohort_ = cohort; }
  63
  64   // Sets the secret value. For use by tests only.
  65   void SetSecretForTesting(const std::string& secret) { secret_ = secret; }
  66
  67   // Registers the names of all of the preferences used by RapporService in the
  68   // provided PrefRegistry. This should be called before calling Start().
  69   static void RegisterPrefs(PrefRegistrySimple* registry);
  70
  71  protected:
  72   // Retrieves the cohort number this client was assigned to, generating it if
  73   // doesn't already exist. The cohort should be persistent.
  74   void LoadCohort();
  75
  76   // Retrieves the value for secret_ from preferences, generating it if doesn't
  77   // already exist. The secret should be persistent, so that additional bits
  78   // from the client do not get exposed over time.
  79   void LoadSecret();
  80
  81   // Logs all of the collected metrics to the reports proto message and clears
  82   // the internal map. Exposed for tests. Returns true if any metrics were
  83   // recorded.
  84   bool ExportMetrics(RapporReports* reports);
  85
  86   // Records a sample of the rappor metric specified by |parameters|.
  87   // Creates and initializes the metric, if it doesn't yet exist.
  88   // Exposed for tests.
  89   void RecordSampleInternal(const std::string& metric_name,
  90                             const RapporParameters& parameters,
  91                             const std::string& sample);
  92
  93  private:
  94   // Check if the service has been started successfully.
  95   bool IsInitialized() const;
  96
  97   // Called whenever the logging interval elapses to generate a new log of
  98   // reports and pass it to the uploader.
  99   void OnLogInterval();
 100
 101   // Finds a metric in the metrics_map_, creating it if it doesn't already
 102   // exist.
 103   RapporMetric* LookUpMetric(const std::string& metric_name,
 104                              const RapporParameters& parameters);
 105
 106   // A weak pointer to the PrefService used to read and write preferences.
 107   PrefService* pref_service_;
 108
 109   // Client-side secret used to generate fake bits.
 110   std::string secret_;
 111
 112   // The cohort this client is assigned to. -1 is uninitialized.
 113   int32_t cohort_;
 114
 115   // Timer which schedules calls to OnLogInterval().
 116   base::OneShotTimer<RapporService> log_rotation_timer_;
 117
 118   // A daily event for collecting metrics once a day.
 119   metrics::DailyEvent daily_event_;
 120
 121   // A private LogUploader instance for sending reports to the server.
 122   scoped_ptr<LogUploader> uploader_;
 123
 124   // We keep all registered metrics in a map, from name to metric.
 125   // The map owns the metrics it contains.
 126   std::map<std::string, RapporMetric*> metrics_map_;
 127
 128   DISALLOW_COPY_AND_ASSIGN(RapporService);
 129 };
 130
 131 }  // namespace rappor
 132
 133 #endif  // COMPONENTS_RAPPOR_RAPPOR_SERVICE_H_