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 #ifndef COMPONENTS_WEBDATA_COMMON_WEB_DATA_SERVICE_BACKEND_H_ 6 #define COMPONENTS_WEBDATA_COMMON_WEB_DATA_SERVICE_BACKEND_H_ 7 8 #include "base/basictypes.h" 9 #include "base/callback_forward.h" 10 #include "base/compiler_specific.h" 11 #include "base/files/file_path.h" 12 #include "base/memory/ref_counted.h" 13 #include "base/memory/ref_counted_delete_on_message_loop.h" 14 #include "base/memory/scoped_ptr.h" 15 #include "base/memory/scoped_vector.h" 16 #include "components/webdata/common/web_database_service.h" 17 #include "components/webdata/common/webdata_export.h" 18 19 class WebDatabase; 20 class WebDatabaseTable; 21 class WebDataRequest; 22 class WebDataRequestManager; 23 24 namespace tracked_objects { 25 class Location; 26 } 27 28 // WebDataServiceBackend handles all database tasks posted by 29 // WebDatabaseService. It is refcounted to allow asynchronous destruction on the 30 // DB thread. 31 32 // TODO(caitkp): Rename this class to WebDatabaseBackend. 33 34 class WEBDATA_EXPORT WebDataServiceBackend 35 : public base::RefCountedDeleteOnMessageLoop<WebDataServiceBackend> { 36 public: 37 class Delegate { 38 public: ~Delegate()39 virtual ~Delegate() {} 40 41 // Invoked when the backend has finished loading the db. 42 virtual void DBLoaded(sql::InitStatus status) = 0; 43 }; 44 45 WebDataServiceBackend(const base::FilePath& path, 46 Delegate* delegate, 47 const scoped_refptr<base::MessageLoopProxy>& db_thread); 48 49 // Must call only before InitDatabaseWithCallback. 50 void AddTable(scoped_ptr<WebDatabaseTable> table); 51 52 // Initializes the database and notifies caller via callback when complete. 53 // Callback is called synchronously. 54 void InitDatabase(); 55 56 // Opens the database file from the profile path if an init has not yet been 57 // attempted. Separated from the constructor to ease construction/destruction 58 // of this object on one thread but database access on the DB thread. Returns 59 // the status of the database. 60 sql::InitStatus LoadDatabaseIfNecessary(); 61 62 // Shuts down the database. 63 void ShutdownDatabase(); 64 65 // Task wrappers to update requests and and notify |request_manager_|. These 66 // are used in cases where the request is being made from the UI thread and an 67 // asyncronous callback is required to notify the client of |request|'s 68 // completion. 69 void DBWriteTaskWrapper( 70 const WebDatabaseService::WriteTask& task, 71 scoped_ptr<WebDataRequest> request); 72 void DBReadTaskWrapper( 73 const WebDatabaseService::ReadTask& task, 74 scoped_ptr<WebDataRequest> request); 75 76 // Task runners to run database tasks. 77 void ExecuteWriteTask(const WebDatabaseService::WriteTask& task); 78 scoped_ptr<WDTypedResult> ExecuteReadTask( 79 const WebDatabaseService::ReadTask& task); 80 request_manager()81 const scoped_refptr<WebDataRequestManager>& request_manager() { 82 return request_manager_; 83 } 84 database()85 WebDatabase* database() { return db_.get(); } 86 87 protected: 88 friend class base::RefCountedDeleteOnMessageLoop<WebDataServiceBackend>; 89 friend class base::DeleteHelper<WebDataServiceBackend>; 90 91 virtual ~WebDataServiceBackend(); 92 93 private: 94 // Commit the current transaction. 95 void Commit(); 96 97 // Path to database file. 98 base::FilePath db_path_; 99 100 // The tables that participate in managing the database. These are 101 // owned here but other than that this class does nothing with 102 // them. Their initialization is in whatever factory creates 103 // WebDatabaseService, and lookup by type is provided by the 104 // WebDatabase class. The tables need to be owned by this refcounted 105 // object, or they themselves would need to be refcounted. Owning 106 // them here rather than having WebDatabase own them makes for 107 // easier unit testing of WebDatabase. 108 ScopedVector<WebDatabaseTable> tables_; 109 110 scoped_ptr<WebDatabase> db_; 111 112 // Keeps track of all pending requests made to the db. 113 scoped_refptr<WebDataRequestManager> request_manager_; 114 115 // State of database initialization. Used to prevent the executing of tasks 116 // before the db is ready. 117 sql::InitStatus init_status_; 118 119 // True if an attempt has been made to load the database (even if the attempt 120 // fails), used to avoid continually trying to reinit if the db init fails. 121 bool init_complete_; 122 123 // Delegate. See the class definition above for more information. 124 scoped_ptr<Delegate> delegate_; 125 126 DISALLOW_COPY_AND_ASSIGN(WebDataServiceBackend); 127 }; 128 129 #endif // COMPONENTS_WEBDATA_COMMON_WEB_DATA_SERVICE_BACKEND_H_ 130