sync/notifier/registration_manager.h

   1 // Copyright 2012 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 // A class that manages the registration of types for server-issued
   6 // notifications.
   7
   8 #ifndef SYNC_NOTIFIER_REGISTRATION_MANAGER_H_
   9 #define SYNC_NOTIFIER_REGISTRATION_MANAGER_H_
  10
  11 #include <map>
  12
  13 #include "base/basictypes.h"
  14 #include "base/threading/non_thread_safe.h"
  15 #include "base/time/time.h"
  16 #include "base/timer/timer.h"
  17 // For invalidation::InvalidationListener::RegistrationState.
  18 #include "google/cacheinvalidation/include/invalidation-listener.h"
  19 #include "google/cacheinvalidation/include/types.h"
  20 #include "sync/base/sync_export.h"
  21 #include "sync/notifier/invalidation_util.h"
  22
  23 namespace syncer {
  24
  25 using ::invalidation::InvalidationListener;
  26
  27 // Manages the details of registering types for invalidation.
  28 // Implements exponential backoff for repeated registration attempts
  29 // to the invalidation client.
  30 //
  31 // TODO(akalin): Consolidate exponential backoff code.  Other
  32 // implementations include the syncer thread (both versions) and XMPP
  33 // retries.  The most sophisticated one is URLRequestThrottler; making
  34 // that generic should work for everyone.
  35 class SYNC_EXPORT_PRIVATE RegistrationManager : public base::NonThreadSafe {
  36  public:
  37   // Constants for exponential backoff (used by tests).
  38   static const int kInitialRegistrationDelaySeconds;
  39   static const int kRegistrationDelayExponent;
  40   static const double kRegistrationDelayMaxJitter;
  41   static const int kMinRegistrationDelaySeconds;
  42   static const int kMaxRegistrationDelaySeconds;
  43
  44   // Types used by testing functions.
  45   struct PendingRegistrationInfo {
  46     PendingRegistrationInfo();
  47
  48     // Last time a registration request was actually sent.
  49     base::Time last_registration_request;
  50     // Time the registration was attempted.
  51     base::Time registration_attempt;
  52     // The calculated delay of the pending registration (which may be
  53     // negative).
  54     base::TimeDelta delay;
  55     // The delay of the timer, which should be max(delay, 0).
  56     base::TimeDelta actual_delay;
  57   };
  58   // Map of object IDs with pending registrations to info about the
  59   // pending registration.
  60   typedef std::map<invalidation::ObjectId,
  61                    PendingRegistrationInfo,
  62                    ObjectIdLessThan>
  63       PendingRegistrationMap;
  64
  65   // Does not take ownership of |invalidation_client_|.
  66   explicit RegistrationManager(
  67       invalidation::InvalidationClient* invalidation_client);
  68
  69   virtual ~RegistrationManager();
  70
  71   // Registers all object IDs included in the given set (that are not
  72   // already disabled) and unregisters all other object IDs. The return value is
  73   // the set of IDs that was unregistered.
  74   ObjectIdSet UpdateRegisteredIds(const ObjectIdSet& ids);
  75
  76   // Marks the registration for the |id| lost and re-registers
  77   // it (unless it's disabled).
  78   void MarkRegistrationLost(const invalidation::ObjectId& id);
  79
  80   // Marks registrations lost for all enabled object IDs and re-registers them.
  81   void MarkAllRegistrationsLost();
  82
  83   // Marks the registration for the |id| permanently lost and blocks any future
  84   // registration attempts.
  85   void DisableId(const invalidation::ObjectId& id);
  86
  87   // Calculate exponential backoff.  |jitter| must be Uniform[-1.0, 1.0].
  88   static double CalculateBackoff(double retry_interval,
  89                                  double initial_retry_interval,
  90                                  double min_retry_interval,
  91                                  double max_retry_interval,
  92                                  double backoff_exponent,
  93                                  double jitter,
  94                                  double max_jitter);
  95
  96   // The functions below should only be used in tests.
  97
  98   // Gets all currently registered ids.
  99   ObjectIdSet GetRegisteredIdsForTest() const;
 100
 101   // Gets all pending registrations and their next min delays.
 102   PendingRegistrationMap GetPendingRegistrationsForTest() const;
 103
 104   // Run pending registrations immediately.
 105   void FirePendingRegistrationsForTest();
 106
 107  protected:
 108   // Overrideable for testing purposes.
 109   virtual double GetJitter();
 110
 111  private:
 112   struct RegistrationStatus {
 113     RegistrationStatus(const invalidation::ObjectId& id,
 114                        RegistrationManager* manager);
 115     ~RegistrationStatus();
 116
 117     // Calls registration_manager->DoRegister(model_type). (needed by
 118     // |registration_timer|).  Should only be called if |enabled| is
 119     // true.
 120     void DoRegister();
 121
 122     // Sets |enabled| to false and resets other variables.
 123     void Disable();
 124
 125     // The object for which this is the status.
 126     const invalidation::ObjectId id;
 127     // The parent registration manager.
 128     RegistrationManager* const registration_manager;
 129
 130     // Whether this data type should be registered.  Set to false if
 131     // we get a non-transient registration failure.
 132     bool enabled;
 133     // The current registration state.
 134     InvalidationListener::RegistrationState state;
 135     // When we last sent a registration request.
 136     base::Time last_registration_request;
 137     // When we last tried to register.
 138     base::Time last_registration_attempt;
 139     // The calculated delay of any pending registration (which may be
 140     // negative).
 141     base::TimeDelta delay;
 142     // The minimum time to wait until any next registration attempt.
 143     // Increased after each consecutive failure.
 144     base::TimeDelta next_delay;
 145     // The actual timer for registration.
 146     base::OneShotTimer<RegistrationStatus> registration_timer;
 147
 148     DISALLOW_COPY_AND_ASSIGN(RegistrationStatus);
 149   };
 150   typedef std::map<invalidation::ObjectId,
 151                    RegistrationStatus*,
 152                    ObjectIdLessThan>
 153       RegistrationStatusMap;
 154
 155   // Does nothing if the given id is disabled.  Otherwise, if
 156   // |is_retry| is not set, registers the given type immediately and
 157   // resets all backoff parameters.  If |is_retry| is set, registers
 158   // the given type at some point in the future and increases the
 159   // delay until the next retry.
 160   void TryRegisterId(const invalidation::ObjectId& id,
 161                      bool is_retry);
 162
 163   // Registers the given id, which must be valid, immediately.
 164   // Updates |last_registration| in the appropriate
 165   // RegistrationStatus.  Should only be called by
 166   // RegistrationStatus::DoRegister().
 167   void DoRegisterId(const invalidation::ObjectId& id);
 168
 169   // Unregisters the given object ID.
 170   void UnregisterId(const invalidation::ObjectId& id);
 171
 172   // Gets all currently registered ids.
 173   ObjectIdSet GetRegisteredIds() const;
 174
 175   // Returns true iff the given object ID is registered.
 176   bool IsIdRegistered(const invalidation::ObjectId& id) const;
 177
 178   RegistrationStatusMap registration_statuses_;
 179   // Weak pointer.
 180   invalidation::InvalidationClient* invalidation_client_;
 181
 182   DISALLOW_COPY_AND_ASSIGN(RegistrationManager);
 183 };
 184
 185 }  // namespace syncer
 186
 187 #endif  // SYNC_NOTIFIER_REGISTRATION_MANAGER_H_