1 // Copyright 2013 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 // Chromium settings and storage represent user-selected preferences and 6 // information and MUST not be extracted, overwritten or modified except 7 // through Chromium defined APIs. 8 9 #ifndef COMPONENTS_WEBDATA_COMMON_WEB_DATABASE_SERVICE_H_ 10 #define COMPONENTS_WEBDATA_COMMON_WEB_DATABASE_SERVICE_H_ 11 12 #include "base/basictypes.h" 13 #include "base/callback_forward.h" 14 #include "base/compiler_specific.h" 15 #include "base/files/file_path.h" 16 #include "base/memory/ref_counted.h" 17 #include "base/memory/ref_counted_delete_on_message_loop.h" 18 #include "base/memory/scoped_ptr.h" 19 #include "base/memory/weak_ptr.h" 20 #include "base/message_loop/message_loop_proxy.h" 21 #include "base/observer_list.h" 22 #include "components/webdata/common/web_data_service_base.h" 23 #include "components/webdata/common/web_database.h" 24 #include "components/webdata/common/webdata_export.h" 25 26 class WebDataServiceBackend; 27 class WebDataRequestManager; 28 29 namespace content { 30 class BrowserContext; 31 } 32 33 namespace tracked_objects { 34 class Location; 35 } 36 37 class WDTypedResult; 38 class WebDataServiceConsumer; 39 40 41 //////////////////////////////////////////////////////////////////////////////// 42 // 43 // WebDatabaseService defines the interface to a generic data repository 44 // responsible for controlling access to the web database (metadata associated 45 // with web pages). 46 // 47 //////////////////////////////////////////////////////////////////////////////// 48 49 class WEBDATA_EXPORT WebDatabaseService 50 : public base::RefCountedDeleteOnMessageLoop<WebDatabaseService> { 51 public: 52 typedef base::Callback<scoped_ptr<WDTypedResult>(WebDatabase*)> ReadTask; 53 typedef base::Callback<WebDatabase::State(WebDatabase*)> WriteTask; 54 55 // Types for managing DB loading callbacks. 56 typedef base::Closure DBLoadedCallback; 57 typedef base::Callback<void(sql::InitStatus)> DBLoadErrorCallback; 58 59 // Takes the path to the WebDatabase file. 60 // WebDatabaseService lives on |ui_thread| and posts tasks to |db_thread|. 61 WebDatabaseService(const base::FilePath& path, 62 const scoped_refptr<base::MessageLoopProxy>& ui_thread, 63 const scoped_refptr<base::MessageLoopProxy>& db_thread); 64 65 // Adds |table| as a WebDatabaseTable that will participate in 66 // managing the database, transferring ownership. All calls to this 67 // method must be made before |LoadDatabase| is called. 68 virtual void AddTable(scoped_ptr<WebDatabaseTable> table); 69 70 // Initializes the web database service. 71 virtual void LoadDatabase(); 72 73 // Unloads the database without actually shutting down the service. This can 74 // be used to temporarily reduce the browser process' memory footprint. 75 virtual void UnloadDatabase(); 76 77 // Unloads database and will not reload. 78 virtual void ShutdownDatabase(); 79 80 // Gets a pointer to the WebDatabase (owned by WebDatabaseService). 81 // TODO(caitkp): remove this method once SyncServices no longer depend on it. 82 virtual WebDatabase* GetDatabaseOnDB() const; 83 84 // Returns a pointer to the WebDataServiceBackend. 85 scoped_refptr<WebDataServiceBackend> GetBackend() const; 86 87 // Schedule an update/write task on the DB thread. 88 virtual void ScheduleDBTask( 89 const tracked_objects::Location& from_here, 90 const WriteTask& task); 91 92 // Schedule a read task on the DB thread. 93 virtual WebDataServiceBase::Handle ScheduleDBTaskWithResult( 94 const tracked_objects::Location& from_here, 95 const ReadTask& task, 96 WebDataServiceConsumer* consumer); 97 98 // Cancel an existing request for a task on the DB thread. 99 // TODO(caitkp): Think about moving the definition of the Handle type to 100 // somewhere else. 101 virtual void CancelRequest(WebDataServiceBase::Handle h); 102 103 // Register a callback to be notified that the database has loaded. Multiple 104 // callbacks may be registered, and each will be called at most once 105 // (following a successful database load), then cleared. 106 // Note: if the database load is already complete, then the callback will NOT 107 // be stored or called. 108 void RegisterDBLoadedCallback(const DBLoadedCallback& callback); 109 110 // Register a callback to be notified that the database has failed to load. 111 // Multiple callbacks may be registered, and each will be called at most once 112 // (following a database load failure), then cleared. 113 // Note: if the database load is already complete, then the callback will NOT 114 // be stored or called. 115 void RegisterDBErrorCallback(const DBLoadErrorCallback& callback); 116 117 bool db_loaded() const { return db_loaded_; }; 118 119 private: 120 class BackendDelegate; 121 friend class BackendDelegate; 122 friend class base::RefCountedDeleteOnMessageLoop<WebDatabaseService>; 123 friend class base::DeleteHelper<WebDatabaseService>; 124 125 typedef std::vector<DBLoadedCallback> LoadedCallbacks; 126 typedef std::vector<DBLoadErrorCallback> ErrorCallbacks; 127 128 virtual ~WebDatabaseService(); 129 130 void OnDatabaseLoadDone(sql::InitStatus status); 131 132 base::FilePath path_; 133 134 // The primary owner is |WebDatabaseService| but is refcounted because 135 // PostTask on DB thread may outlive us. 136 scoped_refptr<WebDataServiceBackend> wds_backend_; 137 138 // All vended weak pointers are invalidated in ShutdownDatabase(). 139 base::WeakPtrFactory<WebDatabaseService> weak_ptr_factory_; 140 141 // Callbacks to be called once the DB has loaded. 142 LoadedCallbacks loaded_callbacks_; 143 144 // Callbacks to be called if the DB has failed to load. 145 ErrorCallbacks error_callbacks_; 146 147 // True if the WebDatabase has loaded. 148 bool db_loaded_; 149 150 scoped_refptr<base::MessageLoopProxy> db_thread_; 151 152 DISALLOW_COPY_AND_ASSIGN(WebDatabaseService); 153 }; 154 155 #endif // COMPONENTS_WEBDATA_COMMON_WEB_DATABASE_SERVICE_H_ 156
