chrome/browser/safe_browsing/incident_reporting/state_store.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 CHROME_BROWSER_SAFE_BROWSING_INCIDENT_REPORTING_STATE_STORE_H_
   6 #define CHROME_BROWSER_SAFE_BROWSING_INCIDENT_REPORTING_STATE_STORE_H_
   7
   8 #include <string>
   9
  10 #include "base/logging.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/prefs/scoped_user_pref_update.h"
  13
  14 class Profile;
  15
  16 namespace safe_browsing {
  17
  18 enum class IncidentType : int32_t;
  19
  20 // The storage to track which incidents have been reported for a profile. Only
  21 // usable on the UI thread.
  22 class StateStore {
  23  public:
  24   using IncidentDigest = uint32_t;
  25
  26   // The result of state store initialization. Values here are used for UMA so
  27   // they must not be changed.
  28   enum InitializationResult {
  29     PSS_NULL = 0,     // The platform state store was absent or not supported.
  30     PSS_EMPTY = 1,    // The platform state store was empty and the pref wasn't.
  31     PSS_DIFFERS = 2,  // The platform state store differed from the preference.
  32     PSS_MATCHES = 3,  // The platform state store matched the preference.
  33     NUM_INITIALIZATION_RESULTS = 4,
  34   };
  35
  36   // An object through which modifications to a StateStore can be made. Changes
  37   // are visible to the StateStore immediately and are written to persistent
  38   // storage when the instance is destroyed (or shortly thereafter). Only one
  39   // transaction may be live for a given StateStore at a given time. Instances
  40   // are typically created on the stack for immediate use.
  41   class Transaction {
  42    public:
  43     explicit Transaction(StateStore* store);
  44     ~Transaction();
  45
  46     // Marks the described incident as having been reported.
  47     void MarkAsReported(IncidentType type,
  48                         const std::string& key,
  49                         IncidentDigest digest);
  50
  51     // Clears all data associated with an incident type.
  52     void ClearForType(IncidentType type);
  53
  54     // Clears all data in the store.
  55     void ClearAll();
  56
  57    private:
  58     friend class StateStore;
  59
  60     // Returns a writable view on the incidents_sent preference. The act of
  61     // obtaining this view will cause a serialize-and-write operation to be
  62     // scheduled when the transaction terminates. Use the store's
  63     // |incidents_sent_| member directly to simply query the preference.
  64     base::DictionaryValue* GetPrefDict();
  65
  66     // Replaces the contents of the underlying dictionary value.
  67     void ReplacePrefDict(scoped_ptr<base::DictionaryValue> pref_dict);
  68
  69     // The store corresponding to this transaction.
  70     StateStore* store_;
  71
  72     // A ScopedUserPrefUpdate through which changes to the incidents_sent
  73     // preference are made.
  74     scoped_ptr<DictionaryPrefUpdate> pref_update_;
  75
  76     DISALLOW_COPY_AND_ASSIGN(Transaction);
  77   };
  78
  79   explicit StateStore(Profile* profile);
  80   ~StateStore();
  81
  82   // Returns true if the described incident has already been reported.
  83   bool HasBeenReported(IncidentType type,
  84                        const std::string& key,
  85                        IncidentDigest digest);
  86
  87  private:
  88   // Called on load to clear values that are no longer used.
  89   void CleanLegacyValues(Transaction* transaction);
  90
  91   // The profile to which this state corresponds.
  92   Profile* profile_;
  93
  94   // A read-only view on the profile's incidents_sent preference.
  95   const base::DictionaryValue* incidents_sent_;
  96
  97 #if DCHECK_IS_ON()
  98   // True when a Transaction instance is outstanding.
  99   bool has_transaction_;
 100 #endif
 101
 102   DISALLOW_COPY_AND_ASSIGN(StateStore);
 103 };
 104
 105 }  // namespace safe_browsing
 106
 107 #endif  // CHROME_BROWSER_SAFE_BROWSING_INCIDENT_REPORTING_STATE_STORE_H_