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      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_SETTINGS_BACKEND_H_
      6 #define CHROME_BROWSER_EXTENSIONS_API_STORAGE_SETTINGS_BACKEND_H_
      7 
      8 #include <map>
      9 #include <set>
     10 #include <string>
     11 
     12 #include "base/compiler_specific.h"
     13 #include "base/files/file_path.h"
     14 #include "base/memory/linked_ptr.h"
     15 #include "base/memory/ref_counted.h"
     16 #include "base/memory/scoped_ptr.h"
     17 #include "chrome/browser/extensions/api/storage/settings_observer.h"
     18 #include "chrome/browser/extensions/api/storage/settings_storage_factory.h"
     19 #include "chrome/browser/extensions/api/storage/settings_storage_quota_enforcer.h"
     20 #include "sync/api/syncable_service.h"
     21 
     22 namespace syncer {
     23 class SyncErrorFactory;
     24 }
     25 
     26 namespace extensions {
     27 
     28 class SettingsSyncProcessor;
     29 class SyncableSettingsStorage;
     30 
     31 // Manages ValueStore objects for extensions, including routing
     32 // changes from sync to them.
     33 // Lives entirely on the FILE thread.
     34 class SettingsBackend : public syncer::SyncableService {
     35  public:
     36   // |storage_factory| is use to create leveldb storage areas.
     37   // |base_path| is the base of the extension settings directory, so the
     38   // databases will be at base_path/extension_id.
     39   // |observers| is the list of observers to settings changes.
     40   SettingsBackend(
     41       const scoped_refptr<SettingsStorageFactory>& storage_factory,
     42       const base::FilePath& base_path,
     43       syncer::ModelType sync_type,
     44       const syncer::SyncableService::StartSyncFlare& flare,
     45       const SettingsStorageQuotaEnforcer::Limits& quota,
     46       const scoped_refptr<SettingsObserverList>& observers);
     47 
     48   virtual ~SettingsBackend();
     49 
     50   // Gets a weak reference to the storage area for |extension_id|.
     51   // Must be run on the FILE thread.
     52   ValueStore* GetStorage(const std::string& extension_id) const;
     53 
     54   // Deletes all setting data for an extension. Call on the FILE thread.
     55   void DeleteStorage(const std::string& extension_id);
     56 
     57   // syncer::SyncableService implementation.
     58   virtual syncer::SyncDataList GetAllSyncData(
     59       syncer::ModelType type) const OVERRIDE;
     60   virtual syncer::SyncMergeResult MergeDataAndStartSyncing(
     61       syncer::ModelType type,
     62       const syncer::SyncDataList& initial_sync_data,
     63       scoped_ptr<syncer::SyncChangeProcessor> sync_processor,
     64       scoped_ptr<syncer::SyncErrorFactory> sync_error_factory) OVERRIDE;
     65   virtual syncer::SyncError ProcessSyncChanges(
     66       const tracked_objects::Location& from_here,
     67       const syncer::SyncChangeList& change_list) OVERRIDE;
     68   virtual void StopSyncing(syncer::ModelType type) OVERRIDE;
     69 
     70  private:
     71   // Gets a weak reference to the storage area for a given extension,
     72   // initializing sync with some initial data if sync enabled.
     73   SyncableSettingsStorage* GetOrCreateStorageWithSyncData(
     74       const std::string& extension_id,
     75       const base::DictionaryValue& sync_data) const;
     76 
     77   // Gets all extension IDs known to extension settings.  This may not be all
     78   // installed extensions.
     79   std::set<std::string> GetKnownExtensionIDs() const;
     80 
     81   // Creates a new SettingsSyncProcessor for an extension.
     82   scoped_ptr<SettingsSyncProcessor> CreateSettingsSyncProcessor(
     83       const std::string& extension_id) const;
     84 
     85   // The Factory to use for creating leveldb storage areas.
     86   const scoped_refptr<SettingsStorageFactory> storage_factory_;
     87 
     88   // The base file path to create any leveldb databases at.
     89   const base::FilePath base_path_;
     90 
     91   // Quota limits (see SettingsStorageQuotaEnforcer).
     92   const SettingsStorageQuotaEnforcer::Limits quota_;
     93 
     94   // The list of observers to settings changes.
     95   const scoped_refptr<SettingsObserverList> observers_;
     96 
     97   // A cache of ValueStore objects that have already been created.
     98   // Ensure that there is only ever one created per extension.
     99   typedef std::map<std::string, linked_ptr<SyncableSettingsStorage> >
    100       StorageObjMap;
    101   mutable StorageObjMap storage_objs_;
    102 
    103   // Current sync model type. Either EXTENSION_SETTINGS or APP_SETTINGS.
    104   syncer::ModelType sync_type_;
    105 
    106   // Current sync processor, if any.
    107   scoped_ptr<syncer::SyncChangeProcessor> sync_processor_;
    108 
    109   // Current sync error handler if any.
    110   scoped_ptr<syncer::SyncErrorFactory> sync_error_factory_;
    111 
    112   syncer::SyncableService::StartSyncFlare flare_;
    113 
    114   DISALLOW_COPY_AND_ASSIGN(SettingsBackend);
    115 };
    116 
    117 }  // namespace extensions
    118 
    119 #endif  // CHROME_BROWSER_EXTENSIONS_API_STORAGE_SETTINGS_BACKEND_H_
    120