chrome/browser/policy/cloud/cloud_policy_invalidator.h

   1 // Copyright 2013 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 CHROME_BROWSER_POLICY_CLOUD_CLOUD_POLICY_INVALIDATOR_H_
   6 #define CHROME_BROWSER_POLICY_CLOUD_CLOUD_POLICY_INVALIDATOR_H_
   7
   8 #include <string>
   9
  10 #include "base/basictypes.h"
  11 #include "base/callback.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/memory/weak_ptr.h"
  15 #include "base/threading/thread_checker.h"
  16 #include "components/policy/core/common/cloud/cloud_policy_core.h"
  17 #include "components/policy/core/common/cloud/cloud_policy_store.h"
  18 #include "google/cacheinvalidation/include/types.h"
  19 #include "sync/internal_api/public/base/invalidation.h"
  20 #include "sync/notifier/invalidation_handler.h"
  21
  22 namespace base {
  23 class SequencedTaskRunner;
  24 }
  25
  26 namespace invalidation {
  27 class InvalidationService;
  28 }
  29
  30 namespace policy {
  31
  32 // Listens for and provides policy invalidations.
  33 class CloudPolicyInvalidator : public syncer::InvalidationHandler,
  34                                public CloudPolicyCore::Observer,
  35                                public CloudPolicyStore::Observer {
  36  public:
  37   // The number of minutes to delay a policy refresh after receiving an
  38   // invalidation with no payload.
  39   static const int kMissingPayloadDelay;
  40
  41   // The default, min and max values for max_fetch_delay_.
  42   static const int kMaxFetchDelayDefault;
  43   static const int kMaxFetchDelayMin;
  44   static const int kMaxFetchDelayMax;
  45
  46   // |core| is the cloud policy core which connects the various policy objects.
  47   // It must remain valid until Shutdown is called.
  48   // |task_runner| is used for scheduling delayed tasks. It must post tasks to
  49   // the main policy thread.
  50   CloudPolicyInvalidator(
  51       CloudPolicyCore* core,
  52       const scoped_refptr<base::SequencedTaskRunner>& task_runner);
  53   virtual ~CloudPolicyInvalidator();
  54
  55   // Initializes the invalidator. No invalidations will be generated before this
  56   // method is called. This method must only be called once.
  57   // |invalidation_service| is the invalidation service to use and must remain
  58   // valid until Shutdown is called.
  59   void Initialize(invalidation::InvalidationService* invalidation_service);
  60
  61   // Shuts down and disables invalidations. It must be called before the object
  62   // is destroyed.
  63   void Shutdown();
  64
  65   // Whether the invalidator currently has the ability to receive invalidations.
  66   bool invalidations_enabled() {
  67     return invalidations_enabled_;
  68   }
  69
  70   // syncer::InvalidationHandler:
  71   virtual void OnInvalidatorStateChange(
  72       syncer::InvalidatorState state) OVERRIDE;
  73   virtual void OnIncomingInvalidation(
  74       const syncer::ObjectIdInvalidationMap& invalidation_map) OVERRIDE;
  75
  76   // CloudPolicyCore::Observer:
  77   virtual void OnCoreConnected(CloudPolicyCore* core) OVERRIDE;
  78   virtual void OnRefreshSchedulerStarted(CloudPolicyCore* core) OVERRIDE;
  79   virtual void OnCoreDisconnecting(CloudPolicyCore* core) OVERRIDE;
  80
  81   // CloudPolicyStore::Observer:
  82   virtual void OnStoreLoaded(CloudPolicyStore* store) OVERRIDE;
  83   virtual void OnStoreError(CloudPolicyStore* store) OVERRIDE;
  84
  85  private:
  86   // Handle an invalidation to the policy.
  87   void HandleInvalidation(const syncer::Invalidation& invalidation);
  88
  89   // Update object registration with the invalidation service based on the
  90   // given policy data.
  91   void UpdateRegistration(const enterprise_management::PolicyData* policy);
  92
  93   // Registers the given object with the invalidation service.
  94   void Register(int64 timestamp, const invalidation::ObjectId& object_id);
  95
  96   // Unregisters the current object with the invalidation service.
  97   void Unregister();
  98
  99   // Update |max_fetch_delay_| based on the given policy map.
 100   void UpdateMaxFetchDelay(const PolicyMap& policy_map);
 101   void set_max_fetch_delay(int delay);
 102
 103   // Updates invalidations_enabled_ and calls the invalidation handler if the
 104   // value changed.
 105   void UpdateInvalidationsEnabled();
 106
 107   // Refresh the policy.
 108   // |is_missing_payload| is set to true if the callback is being invoked in
 109   // response to an invalidation with a missing payload.
 110   void RefreshPolicy(bool is_missing_payload);
 111
 112   // Acknowledge the latest invalidation.
 113   void AcknowledgeInvalidation();
 114
 115   // Determines if the given policy is different from the policy passed in the
 116   // previous call.
 117   bool IsPolicyChanged(const enterprise_management::PolicyData* policy);
 118
 119   // Get the kMetricPolicyRefresh histogram metric which should be incremented
 120   // when a policy is stored.
 121   int GetPolicyRefreshMetric(bool policy_changed);
 122
 123   // The state of the object.
 124   enum State {
 125     UNINITIALIZED,
 126     STOPPED,
 127     STARTED,
 128     SHUT_DOWN
 129   };
 130   State state_;
 131
 132   // The cloud policy core.
 133   CloudPolicyCore* core_;
 134
 135   // Schedules delayed tasks.
 136   const scoped_refptr<base::SequencedTaskRunner> task_runner_;
 137
 138   // The invalidation service.
 139   invalidation::InvalidationService* invalidation_service_;
 140
 141   // Whether the invalidator currently has the ability to receive invalidations.
 142   // This is true if the invalidation service is enabled and the invalidator
 143   // has registered for a policy object.
 144   bool invalidations_enabled_;
 145
 146   // Whether the invalidation service is currently enabled.
 147   bool invalidation_service_enabled_;
 148
 149   // The timestamp of the PolicyData at which this object registered for policy
 150   // invalidations. Set to zero if the object has not registered yet.
 151   int64 registered_timestamp_;
 152
 153   // The object id representing the policy in the invalidation service.
 154   invalidation::ObjectId object_id_;
 155
 156   // Whether the policy is current invalid. This is set to true when an
 157   // invalidation is received and reset when the policy fetched due to the
 158   // invalidation is stored.
 159   bool invalid_;
 160
 161   // The version of the latest invalidation received. This is compared to
 162   // the invalidation version of policy stored to determine when the
 163   // invalidated policy is up-to-date.
 164   int64 invalidation_version_;
 165
 166   // The number of invalidations with unknown version received. Since such
 167   // invalidations do not provide a version number, this count is used to set
 168   // invalidation_version_ when such invalidations occur.
 169   int unknown_version_invalidation_count_;
 170
 171   // The most up to date invalidation.
 172   scoped_ptr<syncer::Invalidation> invalidation_;
 173
 174   // WeakPtrFactory used to create callbacks to this object.
 175   base::WeakPtrFactory<CloudPolicyInvalidator> weak_factory_;
 176
 177   // The maximum random delay, in ms, between receiving an invalidation and
 178   // fetching the new policy.
 179   int max_fetch_delay_;
 180
 181   // The hash value of the current policy. This is used to determine if a new
 182   // policy is different from the current one.
 183   uint32 policy_hash_value_;
 184
 185   // A thread checker to make sure that callbacks are invoked on the correct
 186   // thread.
 187   base::ThreadChecker thread_checker_;
 188
 189   DISALLOW_COPY_AND_ASSIGN(CloudPolicyInvalidator);
 190 };
 191
 192 }  // namespace policy
 193
 194 #endif  // CHROME_BROWSER_POLICY_CLOUD_CLOUD_POLICY_INVALIDATOR_H_