chrome/browser/extensions/state_store.h

   1 // Copyright (c) 2012 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_STATE_STORE_H_
   6 #define CHROME_BROWSER_EXTENSIONS_STATE_STORE_H_
   7
   8 #include <set>
   9 #include <string>
  10
  11 #include "base/files/file_path.h"
  12 #include "base/memory/weak_ptr.h"
  13 #include "chrome/browser/value_store/value_store_frontend.h"
  14 #include "content/public/browser/notification_observer.h"
  15 #include "content/public/browser/notification_registrar.h"
  16
  17 class Profile;
  18
  19 namespace extensions {
  20
  21 // A storage area for per-extension state that needs to be persisted to disk.
  22 class StateStore
  23     : public base::SupportsWeakPtr<StateStore>,
  24       public content::NotificationObserver {
  25  public:
  26   typedef ValueStoreFrontend::ReadCallback ReadCallback;
  27
  28   // If |deferred_load| is true, we won't load the database until the first
  29   // page has been loaded.
  30   StateStore(Profile* profile, const base::FilePath& db_path,
  31              bool deferred_load);
  32   // This variant is useful for testing (using a mock ValueStore).
  33   StateStore(Profile* profile, scoped_ptr<ValueStore> store);
  34   virtual ~StateStore();
  35
  36   // Register a key for removal upon extension install/uninstall. We remove
  37   // for install to reset state when an extension upgrades.
  38   void RegisterKey(const std::string& key);
  39
  40   // Get the value associated with the given extension and key, and pass
  41   // it to |callback| asynchronously.
  42   void GetExtensionValue(const std::string& extension_id,
  43                          const std::string& key,
  44                          ReadCallback callback);
  45
  46   // Sets a value for a given extension and key.
  47   void SetExtensionValue(const std::string& extension_id,
  48                          const std::string& key,
  49                          scoped_ptr<base::Value> value);
  50
  51   // Removes a value for a given extension and key.
  52   void RemoveExtensionValue(const std::string& extension_id,
  53                             const std::string& key);
  54
  55  private:
  56   class DelayedTaskQueue;
  57
  58   // content::NotificationObserver
  59   virtual void Observe(int type,
  60                        const content::NotificationSource& source,
  61                        const content::NotificationDetails& details) OVERRIDE;
  62
  63   void Init();
  64
  65   // Removes all keys registered for the given extension.
  66   void RemoveKeysForExtension(const std::string& extension_id);
  67
  68   // Path to our database, on disk. Empty during testing.
  69   base::FilePath db_path_;
  70
  71   // The store that holds our key/values.
  72   ValueStoreFrontend store_;
  73
  74   // List of all known keys. They will be cleared for each extension when it is
  75   // (un)installed.
  76   std::set<std::string> registered_keys_;
  77
  78   // Keeps track of tasks we have delayed while starting up.
  79   scoped_ptr<DelayedTaskQueue> task_queue_;
  80
  81   content::NotificationRegistrar registrar_;
  82 };
  83
  84 }  // namespace extensions
  85
  86 #endif  // CHROME_BROWSER_EXTENSIONS_STATE_STORE_H_