Source/WebCore/Modules/webdatabase/SQLTransactionCoordinator.h

/*
 * Copyright (C) 2009 Google Inc. All rights reserved.
 * Copyright (C) 2013 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include <wtf/Deque.h>
#include <wtf/HashMap.h>
#include <wtf/HashSet.h>
#include <wtf/RefPtr.h>
#include <wtf/text/StringHash.h>

namespace WebCore {

class SQLTransaction;

class SQLTransactionCoordinator {
    WTF_MAKE_NONCOPYABLE(SQLTransactionCoordinator); WTF_MAKE_FAST_ALLOCATED;
public:
    SQLTransactionCoordinator();
    void acquireLock(SQLTransaction&);
    void releaseLock(SQLTransaction&);
    void shutdown();
private:
    typedef Deque<RefPtr<SQLTransaction>> TransactionsQueue;
    struct CoordinationInfo {
        TransactionsQueue pendingTransactions;
        HashSet<RefPtr<SQLTransaction>> activeReadTransactions;
        RefPtr<SQLTransaction> activeWriteTransaction;
    };
    // Maps database names to information about pending transactions
    typedef HashMap<String, CoordinationInfo> CoordinationInfoMap;
    CoordinationInfoMap m_coordinationInfoMap;
    bool m_isShuttingDown;

    void processPendingTransactions(CoordinationInfo&);
};

} // namespace WebCore