chrome/browser/extensions/api/declarative/rules_cache_delegate.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_EXTENSIONS_API_DECLARATIVE_RULES_CACHE_DELEGATE_H__
   6 #define CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_RULES_CACHE_DELEGATE_H__
   7
   8 #include <set>
   9 #include <string>
  10
  11 #include "base/gtest_prod_util.h"
  12 #include "base/values.h"
  13 #include "content/public/browser/browser_thread.h"
  14
  15 class Profile;
  16
  17 namespace extensions {
  18
  19 class RulesRegistry;
  20
  21 // RulesCacheDelegate implements the part of the RulesRegistry which works on
  22 // the UI thread. It should only be used on the UI thread.
  23 // If |log_storage_init_delay| is set, the delay caused by loading and
  24 // registering rules on initialization will be logged with UMA.
  25 class RulesCacheDelegate {
  26  public:
  27
  28   explicit RulesCacheDelegate(bool log_storage_init_delay);
  29
  30   virtual ~RulesCacheDelegate();
  31
  32   // Returns a key for the state store. The associated preference is a boolean
  33   // indicating whether there are some declarative rules stored in the rule
  34   // store.
  35   static std::string GetRulesStoredKey(const std::string& event_name,
  36                                        bool incognito);
  37
  38   // Initialize the storage functionality.
  39   void Init(RulesRegistry* registry);
  40
  41   void WriteToStorage(const std::string& extension_id,
  42                       scoped_ptr<base::Value> value);
  43
  44   base::WeakPtr<RulesCacheDelegate> GetWeakPtr() {
  45     DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  46     return weak_ptr_factory_.GetWeakPtr();
  47   }
  48
  49  private:
  50   FRIEND_TEST_ALL_PREFIXES(RulesRegistryWithCacheTest,
  51                            DeclarativeRulesStored);
  52   FRIEND_TEST_ALL_PREFIXES(RulesRegistryWithCacheTest,
  53                            RulesStoredFlagMultipleRegistries);
  54
  55   static const char kRulesStoredKey[];
  56
  57   // Check if we are done reading all data from storage on startup, and notify
  58   // the RulesRegistry on its thread if so. The notification is delivered
  59   // exactly once.
  60   void CheckIfReady();
  61
  62   // Schedules retrieving rules for already loaded extensions where
  63   // appropriate.
  64   void ReadRulesForInstalledExtensions();
  65
  66   // Read/write a list of rules serialized to Values.
  67   void ReadFromStorage(const std::string& extension_id);
  68   void ReadFromStorageCallback(const std::string& extension_id,
  69                                scoped_ptr<base::Value> value);
  70
  71   // Check the preferences whether the extension with |extension_id| has some
  72   // rules stored on disk. If this information is not in the preferences, true
  73   // is returned as a safe default value.
  74   bool GetDeclarativeRulesStored(const std::string& extension_id) const;
  75   // Modify the preference to |rules_stored|.
  76   void SetDeclarativeRulesStored(const std::string& extension_id,
  77                                  bool rules_stored);
  78
  79   Profile* profile_;
  80
  81   // The key under which rules are stored.
  82   std::string storage_key_;
  83
  84   // The key under which we store whether the rules have been stored.
  85   std::string rules_stored_key_;
  86
  87   // A set of extension IDs that have rules we are reading from storage.
  88   std::set<std::string> waiting_for_extensions_;
  89
  90   // We measure the time spent on loading rules on init. The result is logged
  91   // with UMA once per each RulesCacheDelegate instance, unless in Incognito.
  92   base::Time storage_init_time_;
  93   bool log_storage_init_delay_;
  94
  95   // Weak pointer to post tasks to the owning rules registry.
  96   base::WeakPtr<RulesRegistry> registry_;
  97
  98   // The thread |registry_| lives on.
  99   content::BrowserThread::ID rules_registry_thread_;
 100
 101   // We notified the RulesRegistry that the rules are loaded.
 102   bool notified_registry_;
 103
 104   // Use this factory to generate weak pointers bound to the UI thread.
 105   base::WeakPtrFactory<RulesCacheDelegate> weak_ptr_factory_;
 106 };
 107
 108 }  // namespace extensions
 109
 110 #endif  // CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_RULES_CACHE_DELEGATE_H__