efdcd1de90c9cc3079a03554a0993e0041e99871
[WebKit-https.git] / WebCore / storage / SQLTransactionCoordinator.cpp
1 /*
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11  * copyright notice, this list of conditions and the following disclaimer
12  * in the documentation and/or other materials provided with the
13  * distribution.
14  *     * Neither the name of Google Inc. nor the names of its
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16  * this software without specific prior written permission.
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19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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30
31 #include "config.h"
32 #include "SQLTransactionCoordinator.h"
33
34 #if ENABLE(DATABASE)
35
36 #include "CString.h"
37 #include "Database.h"
38 #include "SQLTransaction.h"
39 #include <wtf/Deque.h>
40 #include <wtf/HashMap.h>
41 #include <wtf/HashSet.h>
42 #include <wtf/RefPtr.h>
43
44 namespace WebCore {
45
46 static String getDatabaseIdentifier(SQLTransaction* transaction)
47 {
48     Database* database = transaction->database();
49     ASSERT(database);
50     return database->stringIdentifier();
51 }
52
53 void SQLTransactionCoordinator::processPendingTransactions(CoordinationInfo& info)
54 {
55     if (info.activeWriteTransaction || info.pendingTransactions.isEmpty())
56         return;
57
58     RefPtr<SQLTransaction> firstPendingTransaction = info.pendingTransactions.first();
59     if (firstPendingTransaction->isReadOnly()) {
60         do {
61             firstPendingTransaction = info.pendingTransactions.first();
62             info.pendingTransactions.removeFirst();
63             info.activeReadTransactions.add(firstPendingTransaction);
64             firstPendingTransaction->lockAcquired();
65         } while (!info.pendingTransactions.isEmpty() && info.pendingTransactions.first()->isReadOnly());
66     } else if (info.activeReadTransactions.isEmpty()) {
67         info.pendingTransactions.removeFirst();
68         info.activeWriteTransaction = firstPendingTransaction;
69         firstPendingTransaction->lockAcquired();
70     }
71 }
72
73 void SQLTransactionCoordinator::acquireLock(SQLTransaction* transaction)
74 {
75     String dbIdentifier = getDatabaseIdentifier(transaction);
76
77     CoordinationInfoMap::iterator coordinationInfoIterator = m_coordinationInfoMap.find(dbIdentifier);
78     if (coordinationInfoIterator == m_coordinationInfoMap.end()) {
79         // No pending transactions for this DB
80         coordinationInfoIterator = m_coordinationInfoMap.add(dbIdentifier, CoordinationInfo()).first;
81     }
82
83     CoordinationInfo& info = coordinationInfoIterator->second;
84     info.pendingTransactions.append(transaction);
85     processPendingTransactions(info);
86 }
87
88 void SQLTransactionCoordinator::releaseLock(SQLTransaction* transaction)
89 {
90     if (m_coordinationInfoMap.isEmpty())
91         return;
92
93     String dbIdentifier = getDatabaseIdentifier(transaction);
94
95     CoordinationInfoMap::iterator coordinationInfoIterator = m_coordinationInfoMap.find(dbIdentifier);
96     ASSERT(coordinationInfoIterator != m_coordinationInfoMap.end());
97     CoordinationInfo& info = coordinationInfoIterator->second;
98
99     if (transaction->isReadOnly()) {
100         ASSERT(info.activeReadTransactions.contains(transaction));
101         info.activeReadTransactions.remove(transaction);
102     } else {
103         ASSERT(info.activeWriteTransaction == transaction);
104         info.activeWriteTransaction = 0;
105     }
106
107     processPendingTransactions(info);
108 }
109
110 void SQLTransactionCoordinator::shutdown()
111 {
112     // Clean up all pending transactions for all databases
113     m_coordinationInfoMap.clear();
114 }
115
116 } // namespace WebCore
117
118 #endif // ENABLE(DATABASE)