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 COMPONENTS_WEBDATA_COMMON_WEB_DATA_SERVICE_BASE_H_ 6 #define COMPONENTS_WEBDATA_COMMON_WEB_DATA_SERVICE_BASE_H_ 7 8 #include "base/callback.h" 9 #include "base/files/file_path.h" 10 #include "base/memory/ref_counted.h" 11 #include "base/memory/ref_counted_delete_on_message_loop.h" 12 #include "base/memory/scoped_ptr.h" 13 #include "components/webdata/common/webdata_export.h" 14 #include "sql/init_status.h" 15 16 class WebDatabase; 17 class WebDatabaseService; 18 class WebDatabaseTable; 19 20 namespace base { 21 class Thread; 22 } 23 24 // Base for WebDataService class hierarchy. 25 // WebDataServiceBase is destroyed on the UI thread. 26 class WEBDATA_EXPORT WebDataServiceBase 27 : public base::RefCountedDeleteOnMessageLoop<WebDataServiceBase> { 28 public: 29 // All requests return an opaque handle of the following type. 30 typedef int Handle; 31 32 // Users of this class may provide a callback to handle errors 33 // (e.g. by showing a UI). The callback is called only on error, and 34 // takes a single parameter, the sql::InitStatus value from trying 35 // to open the database. 36 // TODO(joi): Should we combine this with WebDatabaseService::InitCallback? 37 typedef base::Callback<void(sql::InitStatus)> ProfileErrorCallback; 38 39 typedef base::Closure DBLoadedCallback; 40 41 // |callback| will only be invoked on error, and only if 42 // |callback.is_null()| evaluates to false. 43 // 44 // The ownership of |wdbs| is shared, with the primary owner being the 45 // WebDataServiceWrapper, and secondary owners being subclasses of 46 // WebDataServiceBase, which receive |wdbs| upon construction. The 47 // WebDataServiceWrapper handles the initializing and shutting down and of 48 // the |wdbs| object. 49 // WebDataServiceBase is destroyed on |ui_thread|. 50 WebDataServiceBase(scoped_refptr<WebDatabaseService> wdbs, 51 const ProfileErrorCallback& callback, 52 const scoped_refptr<base::MessageLoopProxy>& ui_thread); 53 54 // Cancel any pending request. You need to call this method if your 55 // WebDataServiceConsumer is about to be deleted. 56 virtual void CancelRequest(Handle h); 57 58 // Shutdown the web data service. The service can no longer be used after this 59 // call. 60 virtual void ShutdownOnUIThread(); 61 62 // Initializes the web data service. 63 virtual void Init(); 64 65 // Unloads the database without actually shutting down the service. This can 66 // be used to temporarily reduce the browser process' memory footprint. 67 void UnloadDatabase(); 68 69 // Unloads the database permanently and shuts down service. 70 void ShutdownDatabase(); 71 72 // Register a callback to be notified that the database has loaded. Multiple 73 // callbacks may be registered, and each will be called at most once 74 // (following a successful database load), then cleared. 75 // Note: if the database load is already complete, then the callback will NOT 76 // be stored or called. 77 virtual void RegisterDBLoadedCallback(const DBLoadedCallback& callback); 78 79 // Returns true if the database load has completetd successfully, and 80 // ShutdownOnUIThread has not yet been called. 81 virtual bool IsDatabaseLoaded(); 82 83 // Returns a pointer to the DB (used by SyncableServices). May return NULL if 84 // the database is not loaded or otherwise unavailable. Must be called on 85 // DBThread. 86 virtual WebDatabase* GetDatabase(); 87 88 protected: 89 friend class base::RefCountedDeleteOnMessageLoop<WebDataServiceBase>; 90 friend class base::DeleteHelper<WebDataServiceBase>; 91 92 virtual ~WebDataServiceBase(); 93 94 // Our database service. 95 scoped_refptr<WebDatabaseService> wdbs_; 96 97 private: 98 ProfileErrorCallback profile_error_callback_; 99 100 DISALLOW_COPY_AND_ASSIGN(WebDataServiceBase); 101 }; 102 103 #endif // COMPONENTS_WEBDATA_COMMON_WEB_DATA_SERVICE_BASE_H_ 104
