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#include "config.h"
27#include "IDBTransactionCoordinator.h"
28
29#if ENABLE(INDEXED_DATABASE)
30
31#include "IDBDatabaseBackendImpl.h"
32#include "IDBObjectStoreBackendInterface.h"
33#include "IDBTransactionBackendImpl.h"
34#include "ScriptExecutionContext.h"
35
36namespace WebCore {
37
38PassRefPtr<IDBTransactionCoordinator> IDBTransactionCoordinator::create()
39{
40    return adoptRef(new IDBTransactionCoordinator());
41}
42
43IDBTransactionCoordinator::IDBTransactionCoordinator()
44{
45}
46
47IDBTransactionCoordinator::~IDBTransactionCoordinator()
48{
49}
50
51void IDBTransactionCoordinator::didCreateTransaction(IDBTransactionBackendImpl* transaction)
52{
53    ASSERT(!m_transactions.contains(transaction));
54    m_transactions.add(transaction, transaction);
55}
56
57void IDBTransactionCoordinator::didStartTransaction(IDBTransactionBackendImpl* transaction)
58{
59    ASSERT(m_transactions.contains(transaction));
60
61    m_startedTransactions.add(transaction);
62    processStartedTransactions();
63}
64
65void IDBTransactionCoordinator::didFinishTransaction(IDBTransactionBackendImpl* transaction)
66{
67    ASSERT(m_transactions.contains(transaction));
68
69    if (m_startedTransactions.contains(transaction)) {
70        ASSERT(!m_runningTransactions.contains(transaction));
71        m_startedTransactions.remove(transaction);
72    } else if (m_runningTransactions.contains(transaction))
73        m_runningTransactions.remove(transaction);
74
75    m_transactions.remove(transaction);
76
77    processStartedTransactions();
78}
79
80#ifndef NDEBUG
81// Verifies internal consistiency while returning whether anything is found.
82bool IDBTransactionCoordinator::isActive(IDBTransactionBackendImpl* transaction)
83{
84    bool found = false;
85    if (m_startedTransactions.contains(transaction))
86        found = true;
87    if (m_runningTransactions.contains(transaction)) {
88        ASSERT(!found);
89        found = true;
90    }
91    ASSERT(found == m_transactions.contains(transaction));
92    return found;
93}
94#endif
95
96void IDBTransactionCoordinator::processStartedTransactions()
97{
98    // FIXME: For now, we only allow one transaction to run at a time.
99    if (!m_runningTransactions.isEmpty())
100        return;
101
102    if (m_startedTransactions.isEmpty())
103        return;
104
105    IDBTransactionBackendImpl* transaction = *m_startedTransactions.begin();
106    m_startedTransactions.remove(transaction);
107    m_runningTransactions.add(transaction);
108    transaction->run();
109}
110
111};
112
113#endif // ENABLE(INDEXED_DATABASE)
114