extensions/browser/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 EXTENSIONS_BROWSER_API_DECLARATIVE_RULES_CACHE_DELEGATE_H__
   6 #define EXTENSIONS_BROWSER_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 namespace content {
  16 class BrowserContext;
  17 }
  18
  19 namespace extensions {
  20
  21 class RulesRegistry;
  22
  23 // RulesCacheDelegate implements the part of the RulesRegistry which works on
  24 // the UI thread. It should only be used on the UI thread.
  25 // If |log_storage_init_delay| is set, the delay caused by loading and
  26 // registering rules on initialization will be logged with UMA.
  27 class RulesCacheDelegate {
  28  public:
  29
  30   explicit RulesCacheDelegate(bool log_storage_init_delay);
  31
  32   virtual ~RulesCacheDelegate();
  33
  34   // Returns a key for the state store. The associated preference is a boolean
  35   // indicating whether there are some declarative rules stored in the rule
  36   // store.
  37   static std::string GetRulesStoredKey(const std::string& event_name,
  38                                        bool incognito);
  39
  40   // Initialize the storage functionality.
  41   void Init(RulesRegistry* registry);
  42
  43   void WriteToStorage(const std::string& extension_id,
  44                       scoped_ptr<base::Value> value);
  45
  46   base::WeakPtr<RulesCacheDelegate> GetWeakPtr() {
  47     DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  48     return weak_ptr_factory_.GetWeakPtr();
  49   }
  50
  51  private:
  52   FRIEND_TEST_ALL_PREFIXES(RulesRegistryWithCacheTest,
  53                            DeclarativeRulesStored);
  54   FRIEND_TEST_ALL_PREFIXES(RulesRegistryWithCacheTest,
  55                            RulesStoredFlagMultipleRegistries);
  56
  57   static const char kRulesStoredKey[];
  58
  59   // Check if we are done reading all data from storage on startup, and notify
  60   // the RulesRegistry on its thread if so. The notification is delivered
  61   // exactly once.
  62   void CheckIfReady();
  63
  64   // Schedules retrieving rules for already loaded extensions where
  65   // appropriate.
  66   void ReadRulesForInstalledExtensions();
  67
  68   // Read/write a list of rules serialized to Values.
  69   void ReadFromStorage(const std::string& extension_id);
  70   void ReadFromStorageCallback(const std::string& extension_id,
  71                                scoped_ptr<base::Value> value);
  72
  73   // Check the preferences whether the extension with |extension_id| has some
  74   // rules stored on disk. If this information is not in the preferences, true
  75   // is returned as a safe default value.
  76   bool GetDeclarativeRulesStored(const std::string& extension_id) const;
  77   // Modify the preference to |rules_stored|.
  78   void SetDeclarativeRulesStored(const std::string& extension_id,
  79                                  bool rules_stored);
  80
  81   content::BrowserContext* browser_context_;
  82
  83   // The key under which rules are stored.
  84   std::string storage_key_;
  85
  86   // The key under which we store whether the rules have been stored.
  87   std::string rules_stored_key_;
  88
  89   // A set of extension IDs that have rules we are reading from storage.
  90   std::set<std::string> waiting_for_extensions_;
  91
  92   // We measure the time spent on loading rules on init. The result is logged
  93   // with UMA once per each RulesCacheDelegate instance, unless in Incognito.
  94   base::Time storage_init_time_;
  95   bool log_storage_init_delay_;
  96
  97   // Weak pointer to post tasks to the owning rules registry.
  98   base::WeakPtr<RulesRegistry> registry_;
  99
 100   // The thread |registry_| lives on.
 101   content::BrowserThread::ID rules_registry_thread_;
 102
 103   // We notified the RulesRegistry that the rules are loaded.
 104   bool notified_registry_;
 105
 106   // Use this factory to generate weak pointers bound to the UI thread.
 107   base::WeakPtrFactory<RulesCacheDelegate> weak_ptr_factory_;
 108 };
 109
 110 }  // namespace extensions
 111
 112 #endif  // EXTENSIONS_BROWSER_API_DECLARATIVE_RULES_CACHE_DELEGATE_H__