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   // Starts syncing this storage area. Must only be called if sync isn't
  59   // already active.
  60   // |sync_state| is the current state of the extension settings in sync.
  61   // |sync_processor| is used to write out any changes.
  62   // Returns any error when trying to sync, or an empty error on success.
  63   syncer::SyncError StartSyncing(
  64       scoped_ptr<base::DictionaryValue> sync_state,
  65       scoped_ptr<SettingsSyncProcessor> sync_processor);
  66
  67   // Stops syncing this storage area. May be called at any time (idempotent).
  68   void StopSyncing();
  69
  70   // Pushes a list of sync changes into this storage area. May be called at any
  71   // time, changes will be ignored if sync isn't active.
  72   // Returns any error when trying to sync, or an empty error on success.
  73   syncer::SyncError ProcessSyncChanges(
  74       scoped_ptr<SettingSyncDataList> sync_changes);
  75
  76  private:
  77   // Sends the changes from |result| to sync if it's enabled.
  78   void SyncResultIfEnabled(const ValueStore::WriteResult& result);
  79
  80   // Sends all local settings to sync. This assumes that there are no settings
  81   // in sync yet.
  82   // Returns any error when trying to sync, or an empty error on success.
  83   syncer::SyncError SendLocalSettingsToSync(
  84       scoped_ptr<base::DictionaryValue> local_state);
  85
  86   // Overwrites local state with sync state.
  87   // Returns any error when trying to sync, or an empty error on success.
  88   syncer::SyncError OverwriteLocalSettingsWithSync(
  89       scoped_ptr<base::DictionaryValue> sync_state,
  90       scoped_ptr<base::DictionaryValue> local_state);
  91
  92   // Called when an Add/Update/Remove comes from sync. Ownership of Value*s
  93   // are taken.
  94   syncer::SyncError OnSyncAdd(
  95       const std::string& key,
  96       base::Value* new_value,
  97       ValueStoreChangeList* changes);
  98   syncer::SyncError OnSyncUpdate(
  99       const std::string& key,
 100       base::Value* old_value,
 101       base::Value* new_value,
 102       ValueStoreChangeList* changes);
 103   syncer::SyncError OnSyncDelete(
 104       const std::string& key,
 105       base::Value* old_value,
 106       ValueStoreChangeList* changes);
 107
 108   // List of observers to settings changes.
 109   const scoped_refptr<SettingsObserverList> observers_;
 110
 111   // Id of the extension these settings are for.
 112   std::string const extension_id_;
 113
 114   // Storage area to sync.
 115   const scoped_ptr<ValueStore> delegate_;
 116
 117   // Object which sends changes to sync.
 118   scoped_ptr<SettingsSyncProcessor> sync_processor_;
 119
 120   const syncer::ModelType sync_type_;
 121   const syncer::SyncableService::StartSyncFlare flare_;
 122
 123   DISALLOW_COPY_AND_ASSIGN(SyncableSettingsStorage);
 124 };
 125
 126 }  // namespace extensions
 127
 128 #endif  // CHROME_BROWSER_EXTENSIONS_API_STORAGE_SYNCABLE_SETTINGS_STORAGE_H_