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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_API_WEBDATA_WEB_DATA_SERVICE_BASE_H_ | |
6 #define CHROME_BROWSER_API_WEBDATA_WEB_DATA_SERVICE_BASE_H_ | |
7 | |
8 #include "base/callback_forward.h" | |
9 #include "base/files/file_path.h" | |
10 #include "base/memory/ref_counted.h" | |
11 #include "base/memory/scoped_ptr.h" | |
12 #include "base/supports_user_data.h" | |
13 #include "content/public/browser/browser_thread.h" | |
14 #include "content/public/browser/notification_source.h" | |
15 #include "sql/init_status.h" | |
16 | |
17 class WebDatabase; | |
18 class WebDatabaseService; | |
19 class WebDatabaseTable; | |
20 | |
21 namespace base { | |
22 class Thread; | |
23 } | |
24 | |
25 // Base for WebDataService class hierarchy. | |
26 class WebDataServiceBase | |
27 : public base::RefCountedThreadSafe<WebDataServiceBase, | |
28 content::BrowserThread::DeleteOnUIThread> { | |
29 public: | |
30 // All requests return an opaque handle of the following type. | |
31 typedef int Handle; | |
32 | |
33 // Users of this class may provide a callback to handle errors | |
34 // (e.g. by showing a UI). The callback is called only on error, and | |
35 // takes a single parameter, the sql::InitStatus value from trying | |
36 // to open the database. | |
37 // TODO(joi): Should we combine this with WebDatabaseService::InitCallback? | |
38 typedef base::Callback<void(sql::InitStatus)> ProfileErrorCallback; | |
39 | |
40 // |callback| will only be invoked on error, and only if | |
41 // |callback.is_null()| evaluates to false. | |
42 // | |
43 // The ownership of |wdbs| is shared, with the primary owner being the | |
44 // WebDataServiceWrapper, and secondary owners being subclasses of | |
45 // WebDataServiceBase, which receive |wdbs| upon construction. The | |
46 // WebDataServiceWrapper handles the initializing and shutting down and of | |
47 // the |wdbs| object. | |
48 WebDataServiceBase(scoped_refptr<WebDatabaseService> wdbs, | |
49 const ProfileErrorCallback& callback); | |
50 | |
51 // Cancel any pending request. You need to call this method if your | |
52 // WebDataServiceConsumer is about to be deleted. | |
53 virtual void CancelRequest(Handle h); | |
54 | |
55 // Returns the notification source for this service. This may use a | |
56 // pointer other than this object's |this| pointer. | |
57 virtual content::NotificationSource GetNotificationSource(); | |
58 | |
59 // Shutdown the web data service. The service can no longer be used after this | |
60 // call. | |
61 virtual void ShutdownOnUIThread(); | |
62 | |
63 // Initializes the web data service. | |
64 virtual void Init(); | |
65 | |
66 // Unloads the database without actually shutting down the service. This can | |
67 // be used to temporarily reduce the browser process' memory footprint. | |
68 void UnloadDatabase(); | |
69 | |
70 // Unloads the database permanently and shuts down service. | |
71 void ShutdownDatabase(); | |
72 | |
73 // Returns true if the database load has completetd successfully, and | |
74 // ShutdownOnUIThread has not yet been called. | |
75 virtual bool IsDatabaseLoaded(); | |
76 | |
77 // Returns a pointer to the DB (used by SyncableServices). May return NULL if | |
78 // the database is not loaded or otherwise unavailable. Must be called on | |
79 // DBThread. | |
80 virtual WebDatabase* GetDatabase(); | |
81 | |
82 // Returns a SupportsUserData objects that may be used to store data | |
83 // owned by the DB thread on this object. Should be called only from | |
84 // the DB thread, and will be destroyed on the DB thread soon after | |
85 // |ShutdownOnUIThread()| is called. | |
86 base::SupportsUserData* GetDBUserData(); | |
87 | |
88 protected: | |
89 virtual ~WebDataServiceBase(); | |
90 virtual void ShutdownOnDBThread(); | |
91 | |
92 // Our database service. | |
93 scoped_refptr<WebDatabaseService> wdbs_; | |
94 | |
95 // True if we've received a notification that the WebDatabase has loaded. | |
96 bool db_loaded_; | |
97 | |
98 private: | |
99 friend struct content::BrowserThread::DeleteOnThread< | |
100 content::BrowserThread::UI>; | |
101 friend class base::DeleteHelper<WebDataServiceBase>; | |
102 | |
103 ProfileErrorCallback profile_error_callback_; | |
104 | |
105 // This makes the destructor public, and thus allows us to aggregate | |
106 // SupportsUserData. It is private by default to prevent incorrect | |
107 // usage in class hierarchies where it is inherited by | |
108 // reference-counted objects. | |
109 class SupportsUserDataAggregatable : public base::SupportsUserData { | |
110 public: | |
111 SupportsUserDataAggregatable() {} | |
112 virtual ~SupportsUserDataAggregatable() {} | |
113 private: | |
114 DISALLOW_COPY_AND_ASSIGN(SupportsUserDataAggregatable); | |
115 }; | |
116 | |
117 // Storage for user data to be accessed only on the DB thread. May | |
118 // be used e.g. for SyncableService subclasses that need to be owned | |
119 // by this object. Is created on first call to |GetDBUserData()|. | |
120 scoped_ptr<SupportsUserDataAggregatable> db_thread_user_data_; | |
121 | |
122 // Called after database is successfully loaded. By default this function does | |
123 // nothing. Subclasses can override to support notification. | |
124 virtual void NotifyDatabaseLoadedOnUIThread(); | |
125 | |
126 void DBInitFailed(sql::InitStatus sql_status); | |
127 void DBInitSucceeded(); | |
128 void DatabaseInitOnDB(sql::InitStatus status); | |
129 }; | |
130 | |
131 #endif // CHROME_BROWSER_API_WEBDATA_WEB_DATA_SERVICE_BASE_H_ | |
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