components/webdata/common/web_database_service.h

   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 WebDatabaseBackend;
  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 and shuts down the service.
  74   virtual void ShutdownDatabase();
  75
  76   // Gets a pointer to the WebDatabase (owned by WebDatabaseService).
  77   // TODO(caitkp): remove this method once SyncServices no longer depend on it.
  78   virtual WebDatabase* GetDatabaseOnDB() const;
  79
  80   // Returns a pointer to the WebDatabaseBackend.
  81   scoped_refptr<WebDatabaseBackend> GetBackend() const;
  82
  83   // Schedule an update/write task on the DB thread.
  84   virtual void ScheduleDBTask(
  85       const tracked_objects::Location& from_here,
  86       const WriteTask& task);
  87
  88   // Schedule a read task on the DB thread.
  89   virtual WebDataServiceBase::Handle ScheduleDBTaskWithResult(
  90       const tracked_objects::Location& from_here,
  91       const ReadTask& task,
  92       WebDataServiceConsumer* consumer);
  93
  94   // Cancel an existing request for a task on the DB thread.
  95   // TODO(caitkp): Think about moving the definition of the Handle type to
  96   // somewhere else.
  97   virtual void CancelRequest(WebDataServiceBase::Handle h);
  98
  99   // Register a callback to be notified that the database has loaded. Multiple
 100   // callbacks may be registered, and each will be called at most once
 101   // (following a successful database load), then cleared.
 102   // Note: if the database load is already complete, then the callback will NOT
 103   // be stored or called.
 104   void RegisterDBLoadedCallback(const DBLoadedCallback& callback);
 105
 106   // Register a callback to be notified that the database has failed to load.
 107   // Multiple callbacks may be registered, and each will be called at most once
 108   // (following a database load failure), then cleared.
 109   // Note: if the database load is already complete, then the callback will NOT
 110   // be stored or called.
 111   void RegisterDBErrorCallback(const DBLoadErrorCallback& callback);
 112
 113   bool db_loaded() const { return db_loaded_; };
 114
 115  private:
 116   class BackendDelegate;
 117   friend class BackendDelegate;
 118   friend class base::RefCountedDeleteOnMessageLoop<WebDatabaseService>;
 119   friend class base::DeleteHelper<WebDatabaseService>;
 120
 121   typedef std::vector<DBLoadedCallback> LoadedCallbacks;
 122   typedef std::vector<DBLoadErrorCallback> ErrorCallbacks;
 123
 124   virtual ~WebDatabaseService();
 125
 126   void OnDatabaseLoadDone(sql::InitStatus status);
 127
 128   base::FilePath path_;
 129
 130   // The primary owner is |WebDatabaseService| but is refcounted because
 131   // PostTask on DB thread may outlive us.
 132   scoped_refptr<WebDatabaseBackend> web_db_backend_;
 133
 134   // Callbacks to be called once the DB has loaded.
 135   LoadedCallbacks loaded_callbacks_;
 136
 137   // Callbacks to be called if the DB has failed to load.
 138   ErrorCallbacks error_callbacks_;
 139
 140   // True if the WebDatabase has loaded.
 141   bool db_loaded_;
 142
 143   scoped_refptr<base::MessageLoopProxy> db_thread_;
 144
 145   // All vended weak pointers are invalidated in ShutdownDatabase().
 146   base::WeakPtrFactory<WebDatabaseService> weak_ptr_factory_;
 147
 148   DISALLOW_COPY_AND_ASSIGN(WebDatabaseService);
 149 };
 150
 151 #endif  // COMPONENTS_WEBDATA_COMMON_WEB_DATABASE_SERVICE_H_