1 /*
2  * Copyright (C) 2008, 2009, 2010 Apple Inc. All Rights Reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #ifndef StorageAreaSync_h
27 #define StorageAreaSync_h
28 
29 #if ENABLE(DOM_STORAGE)
30 
31 #include "SQLiteDatabase.h"
32 #include "Timer.h"
33 #include <wtf/HashMap.h>
34 #include <wtf/text/StringHash.h>
35 
36 namespace WebCore {
37 
38     class Frame;
39     class StorageAreaImpl;
40     class StorageSyncManager;
41 
42     class StorageAreaSync : public RefCounted<StorageAreaSync> {
43     public:
44         static PassRefPtr<StorageAreaSync> create(PassRefPtr<StorageSyncManager>, PassRefPtr<StorageAreaImpl>, const String& databaseIdentifier);
45         ~StorageAreaSync();
46 
47         void scheduleFinalSync();
48         void blockUntilImportComplete();
49 
50         void scheduleItemForSync(const String& key, const String& value);
51         void scheduleClear();
52         void scheduleCloseDatabase();
53 
54         void scheduleSync();
55 
56     private:
57         StorageAreaSync(PassRefPtr<StorageSyncManager>, PassRefPtr<StorageAreaImpl>, const String& databaseIdentifier);
58 
59         void dispatchStorageEvent(const String& key, const String& oldValue, const String& newValue, Frame* sourceFrame);
60 
61         Timer<StorageAreaSync> m_syncTimer;
62         HashMap<String, String> m_changedItems;
63         bool m_itemsCleared;
64 
65         bool m_finalSyncScheduled;
66 
67         RefPtr<StorageAreaImpl> m_storageArea;
68         RefPtr<StorageSyncManager> m_syncManager;
69 
70         // The database handle will only ever be opened and used on the background thread.
71         SQLiteDatabase m_database;
72 
73     // The following members are subject to thread synchronization issues.
74     public:
75         // Called from the background thread
76         void performImport();
77         void performSync();
78         void deleteEmptyDatabase();
79 
80     private:
81         enum OpenDatabaseParamType {
82           CreateIfNonExistent,
83           SkipIfNonExistent
84         };
85 
86         void syncTimerFired(Timer<StorageAreaSync>*);
87         void openDatabase(OpenDatabaseParamType openingStrategy);
88         void sync(bool clearItems, const HashMap<String, String>& items);
89 
90         const String m_databaseIdentifier;
91 
92         Mutex m_syncLock;
93         HashMap<String, String> m_itemsPendingSync;
94         bool m_clearItemsWhileSyncing;
95         bool m_syncScheduled;
96         bool m_syncInProgress;
97         bool m_databaseOpenFailed;
98 
99         bool m_syncCloseDatabase;
100 
101         mutable Mutex m_importLock;
102         mutable ThreadCondition m_importCondition;
103         mutable bool m_importComplete;
104         void markImported();
105     };
106 
107 } // namespace WebCore
108 
109 #endif // ENABLE(DOM_STORAGE)
110 
111 #endif // StorageAreaSync_h
112