1/*
2 * Copyright (C) 2010 Google 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 *
8 * 1.  Redistributions of source code must retain the above copyright
9 *     notice, this list of conditions and the following disclaimer.
10 * 2.  Redistributions in binary form must reproduce the above copyright
11 *     notice, this list of conditions and the following disclaimer in the
12 *     documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
16 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
17 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
18 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
19 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
20 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
21 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef IDBTransactionCoordinator_h
27#define IDBTransactionCoordinator_h
28
29#if ENABLE(INDEXED_DATABASE)
30
31#include <wtf/HashMap.h>
32#include <wtf/ListHashSet.h>
33#include <wtf/RefPtr.h>
34
35namespace WebCore {
36
37class IDBTransactionBackendImpl;
38class IDBDatabaseBackendImpl;
39
40// Transactions are executed in the order the were created.
41class IDBTransactionCoordinator {
42public:
43    static PassOwnPtr<IDBTransactionCoordinator> create();
44    virtual ~IDBTransactionCoordinator();
45
46    // Called by transactions as they start and finish.
47    void didCreateTransaction(IDBTransactionBackendImpl*);
48    void didStartTransaction(IDBTransactionBackendImpl*);
49    void didFinishTransaction(IDBTransactionBackendImpl*);
50
51#ifndef NDEBUG
52    bool isActive(IDBTransactionBackendImpl*);
53#endif
54
55private:
56    IDBTransactionCoordinator();
57
58    void processStartedTransactions();
59    bool canRunTransaction(IDBTransactionBackendImpl*);
60
61    // This is just an efficient way to keep references to all transactions.
62    HashMap<IDBTransactionBackendImpl*, RefPtr<IDBTransactionBackendImpl> > m_transactions;
63    // Transactions in different states are grouped below.
64    ListHashSet<IDBTransactionBackendImpl*> m_queuedTransactions;
65    HashSet<IDBTransactionBackendImpl*> m_startedTransactions;
66};
67
68} // namespace WebCore
69
70#endif // ENABLE(INDEXED_DATABASE)
71
72#endif // IDBTransactionCoordinator_h
73