components/password_manager/core/browser/facet_manager.h

   1 // Copyright 2015 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_PASSWORD_MANAGER_CORE_BROWSER_FACET_MANAGER_H_
   6 #define COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_FACET_MANAGER_H_
   7
   8 #include <set>
   9 #include <vector>
  10
  11 #include "base/macros.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "base/time/time.h"
  14 #include "components/password_manager/core/browser/affiliation_service.h"
  15 #include "components/password_manager/core/browser/affiliation_utils.h"
  16
  17 namespace base {
  18 class Clock;
  19 class TaskRunner;
  20 }  // namespace base
  21
  22 namespace password_manager {
  23
  24 class FacetManagerHost;
  25
  26 // Encapsulates the state and logic required for handling affiliation requests
  27 // concerning a single facet. The AffiliationBackend owns one instance for each
  28 // facet that requires attention, and it itself implements the FacetManagerHost
  29 // interface to provide shared functionality needed by all FacetManagers.
  30 class FacetManager {
  31  public:
  32   using StrategyOnCacheMiss = AffiliationService::StrategyOnCacheMiss;
  33
  34   // Both the |backend| and |clock| must outlive this object.
  35   FacetManager(const FacetURI& facet_uri,
  36                FacetManagerHost* backend,
  37                base::Clock* clock);
  38   ~FacetManager();
  39
  40   // Facet-specific implementations for methods in AffiliationService of the
  41   // same name. See documentation in affiliation_service.h for details:
  42   void GetAffiliations(
  43       StrategyOnCacheMiss cache_miss_strategy,
  44       const AffiliationService::ResultCallback& callback,
  45       const scoped_refptr<base::TaskRunner>& callback_task_runner);
  46   void Prefetch(const base::Time& keep_fresh_until);
  47   void CancelPrefetch(const base::Time& keep_fresh_until);
  48
  49   // Called when |affiliation| information regarding this facet has just been
  50   // fetched from the Affiliation API.
  51   void OnFetchSucceeded(const AffiliatedFacetsWithUpdateTime& affiliation);
  52
  53   // Called by the backend when the time specified in RequestNotificationAtTime
  54   // has come to pass, so that |this| can perform delayed administrative tasks.
  55   void NotifyAtRequestedTime();
  56
  57   // Returns whether this instance has becomes redundant, that is, it has no
  58   // more meaningful state than a newly created instance would have.
  59   bool CanBeDiscarded() const;
  60
  61   // Returns whether or not cached data for this facet can be discarded without
  62   // harm when trimming the database.
  63   bool CanCachedDataBeDiscarded() const;
  64
  65   // Returns whether or not affiliation information relating to this facet needs
  66   // to be fetched right now.
  67   bool DoesRequireFetch() const;
  68
  69   // The members below are made public for the sake of tests.
  70
  71   // Returns whether or not cached data for this facet is fresh (not stale).
  72   bool IsCachedDataFresh() const;
  73
  74   // Returns whether or not cached data for this facet is near-stale or stale.
  75   bool IsCachedDataNearStale() const;
  76
  77   // The duration after which cached affiliation data is considered near-stale.
  78   static const int kCacheSoftExpiryInHours;
  79
  80   // The duration after which cached affiliation data is considered stale.
  81   static const int kCacheHardExpiryInHours;
  82
  83  private:
  84   struct RequestInfo;
  85
  86   // Returns the time when the cached data for this facet will become stale.
  87   // The data is considered stale with the returned time value inclusive.
  88   base::Time GetCacheHardExpiryTime() const;
  89
  90   // Returns the time when cached data for this facet becomes near-stale.
  91   // The data is considered near-stale with the returned time value inclusive.
  92   base::Time GetCacheSoftExpiryTime() const;
  93
  94   // Returns the maximum of |keep_fresh_thresholds_|, or the NULL time if the
  95   // set is empty.
  96   base::Time GetMaximumKeepFreshUntilThreshold() const;
  97
  98   // Returns the next time affiliation data for this facet needs to be fetched
  99   // due to active prefetch requests, or base::Time::Max() if not at all.
 100   base::Time GetNextRequiredFetchTimeDueToPrefetch() const;
 101
 102   // Posts the callback of the request described by |request_info| with success.
 103   static void ServeRequestWithSuccess(const RequestInfo& request_info,
 104                                       const AffiliatedFacets& affiliation);
 105
 106   // Posts the callback of the request described by |request_info| with failure.
 107   static void ServeRequestWithFailure(const RequestInfo& request_info);
 108
 109   FacetURI facet_uri_;
 110   FacetManagerHost* backend_;
 111   base::Clock* clock_;
 112
 113   // The last time affiliation information was fetched for this facet, i.e. the
 114   // freshness of the data in the cache. If there is no corresponding data in
 115   // the database, this will contain the NULL time. Otherwise, the update time
 116   // in the database should match this value; it is stored to reduce disk I/O.
 117   base::Time last_update_time_;
 118
 119   // Contains information about the GetAffiliations() requests that are waiting
 120   // for the result of looking up this facet.
 121   std::vector<RequestInfo> pending_requests_;
 122
 123   // Keeps track of |keep_fresh_until| thresholds corresponding to Prefetch()
 124   // requests for this facet. Affiliation information for this facet must be
 125   // kept fresh by periodic refetches until at least the maximum time in this
 126   // set (exclusive).
 127   //
 128   // This is not a single timestamp but rather a multiset so that cancellation
 129   // of individual prefetches can be supported even if there are two requests
 130   // with the same |keep_fresh_until| threshold.
 131   std::multiset<base::Time> keep_fresh_until_thresholds_;
 132
 133   DISALLOW_COPY_AND_ASSIGN(FacetManager);
 134 };
 135
 136 }  // namespace password_manager
 137 #endif  // COMPONENTS_PASSWORD_MANAGER_CORE_BROWSER_FACET_MANAGER_H_