third_party/WebKit/Source/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:
 *
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 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
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 * in the documentation and/or other materials provided with the
 * distribution.
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 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#ifndef SQLTransactionCoordinator_h
#define SQLTransactionCoordinator_h

#include "platform/heap/Handle.h"
#include "wtf/Deque.h"
#include "wtf/HashMap.h"
#include "wtf/HashSet.h"
#include "wtf/text/StringHash.h"

namespace blink {

class SQLTransactionBackend;

class SQLTransactionCoordinator : public GarbageCollected<SQLTransactionCoordinator> {
    WTF_MAKE_NONCOPYABLE(SQLTransactionCoordinator);
public:
    SQLTransactionCoordinator();
    DECLARE_TRACE();
    void acquireLock(SQLTransactionBackend*);
    void releaseLock(SQLTransactionBackend*);
    void shutdown();

private:
    typedef HeapDeque<Member<SQLTransactionBackend>> TransactionsQueue;
    struct CoordinationInfo {
        DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();
    public:
        TransactionsQueue pendingTransactions;
        HeapHashSet<Member<SQLTransactionBackend>> activeReadTransactions;
        Member<SQLTransactionBackend> activeWriteTransaction;

        DEFINE_INLINE_TRACE()
        {
            visitor->trace(pendingTransactions);
            visitor->trace(activeReadTransactions);
            visitor->trace(activeWriteTransaction);
        }
    };
    // Maps database names to information about pending transactions
    typedef HeapHashMap<String, CoordinationInfo> CoordinationInfoHeapMap;
    CoordinationInfoHeapMap m_coordinationInfoMap;
    bool m_isShuttingDown;

    void processPendingTransactions(CoordinationInfo&);
};

} // namespace blink

#endif // SQLTransactionCoordinator_h