chrome/browser/extensions/api/storage/syncable_settings_storage.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_API_STORAGE_SYNCABLE_SETTINGS_STORAGE_H_
   6 #define CHROME_BROWSER_EXTENSIONS_API_STORAGE_SYNCABLE_SETTINGS_STORAGE_H_
   7
   8 #include "base/compiler_specific.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/observer_list_threadsafe.h"
  12 #include "base/values.h"
  13 #include "chrome/browser/extensions/api/storage/setting_sync_data.h"
  14 #include "extensions/browser/api/storage/settings_observer.h"
  15 #include "extensions/browser/value_store/value_store.h"
  16 #include "sync/api/sync_change.h"
  17 #include "sync/api/syncable_service.h"
  18
  19 namespace extensions {
  20
  21 class SettingsSyncProcessor;
  22
  23 // Decorates a ValueStore with sync behaviour.
  24 class SyncableSettingsStorage : public ValueStore {
  25  public:
  26   SyncableSettingsStorage(
  27       const scoped_refptr<SettingsObserverList>& observers,
  28       const std::string& extension_id,
  29       // Ownership taken.
  30       ValueStore* delegate,
  31       syncer::ModelType sync_type,
  32       const syncer::SyncableService::StartSyncFlare& flare);
  33
  34   ~SyncableSettingsStorage() override;
  35
  36   // ValueStore implementation.
  37   size_t GetBytesInUse(const std::string& key) override;
  38   size_t GetBytesInUse(const std::vector<std::string>& keys) override;
  39   size_t GetBytesInUse() override;
  40   ReadResult Get(const std::string& key) override;
  41   ReadResult Get(const std::vector<std::string>& keys) override;
  42   ReadResult Get() override;
  43   WriteResult Set(WriteOptions options,
  44                   const std::string& key,
  45                   const base::Value& value) override;
  46   WriteResult Set(WriteOptions options,
  47                   const base::DictionaryValue& values) override;
  48   WriteResult Remove(const std::string& key) override;
  49   WriteResult Remove(const std::vector<std::string>& keys) override;
  50   WriteResult Clear() override;
  51   bool Restore() override;
  52   bool RestoreKey(const std::string& key) override;
  53
  54   // Sync-related methods, analogous to those on SyncableService (handled by
  55   // ExtensionSettings), but with looser guarantees about when the methods
  56   // can be called.
  57
  58   // Must only be called if sync isn't already active.
  59   syncer::SyncError StartSyncing(
  60       const base::DictionaryValue& sync_state,
  61       scoped_ptr<SettingsSyncProcessor> sync_processor);
  62
  63   // May be called at any time (idempotent).
  64   void StopSyncing();
  65
  66   // May be called at any time; changes will be ignored if sync isn't active.
  67   syncer::SyncError ProcessSyncChanges(const SettingSyncDataList& sync_changes);
  68
  69  private:
  70   // Sends the changes from |result| to sync if it's enabled.
  71   void SyncResultIfEnabled(const ValueStore::WriteResult& result);
  72
  73   // Sends all local settings to sync (synced settings assumed to be empty).
  74   syncer::SyncError SendLocalSettingsToSync(
  75       const base::DictionaryValue& settings);
  76
  77   // Overwrites local state with sync state.
  78   syncer::SyncError OverwriteLocalSettingsWithSync(
  79       const base::DictionaryValue& sync_state,
  80       const base::DictionaryValue& settings);
  81
  82   // Called when an Add/Update/Remove comes from sync.  Ownership of Value*s
  83   // are taken.
  84   syncer::SyncError OnSyncAdd(
  85       const std::string& key,
  86       base::Value* new_value,
  87       ValueStoreChangeList* changes);
  88   syncer::SyncError OnSyncUpdate(
  89       const std::string& key,
  90       base::Value* old_value,
  91       base::Value* new_value,
  92       ValueStoreChangeList* changes);
  93   syncer::SyncError OnSyncDelete(
  94       const std::string& key,
  95       base::Value* old_value,
  96       ValueStoreChangeList* changes);
  97
  98   // List of observers to settings changes.
  99   const scoped_refptr<SettingsObserverList> observers_;
 100
 101   // Id of the extension these settings are for.
 102   std::string const extension_id_;
 103
 104   // Storage area to sync.
 105   const scoped_ptr<ValueStore> delegate_;
 106
 107   // Object which sends changes to sync.
 108   scoped_ptr<SettingsSyncProcessor> sync_processor_;
 109
 110   const syncer::ModelType sync_type_;
 111   const syncer::SyncableService::StartSyncFlare flare_;
 112
 113   DISALLOW_COPY_AND_ASSIGN(SyncableSettingsStorage);
 114 };
 115
 116 }  // namespace extensions
 117
 118 #endif  // CHROME_BROWSER_EXTENSIONS_API_STORAGE_SYNCABLE_SETTINGS_STORAGE_H_