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/*
* Copyright (C) 2010 Google 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:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS 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 APPLE OR ITS 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.
*/
#ifndef IDBTransactionCoordinator_h
#define IDBTransactionCoordinator_h
#if ENABLE(INDEXED_DATABASE)
#include "DOMStringList.h"
#include "IDBTransactionBackendInterface.h"
#include <wtf/ListHashSet.h>
#include <wtf/RefPtr.h>
namespace WebCore {
class IDBTransactionBackendImpl;
class IDBTransactionCallbacks;
class IDBDatabaseBackendImpl;
// This class manages transactions as follows. Requests for new transactions are
// always satisfied and the new transaction is placed in a queue.
// Transactions are not actually started until the first operation is issued.
// Each transaction executes in a separate thread and is committed automatically
// when there are no more operations issued in its context.
// When starting, a transaction will attempt to lock all the object stores in its
// scope. If this does not happen within a given timeout, an exception is raised.
// The Coordinator maintains a pool of threads. If there are no threads available
// the next transaction in the queue will have to wait until a thread becomes
// available.
// Transactions are executed in the order the were created.
class IDBTransactionCoordinator : public RefCounted<IDBTransactionCoordinator> {
public:
static PassRefPtr<IDBTransactionCoordinator> create() { return adoptRef(new IDBTransactionCoordinator()); }
virtual ~IDBTransactionCoordinator();
PassRefPtr<IDBTransactionBackendInterface> createTransaction(DOMStringList* objectStores, unsigned short mode, unsigned long timeout, IDBDatabaseBackendImpl*);
// Called by transactions as they start and finish.
void didStartTransaction(IDBTransactionBackendImpl*);
void didFinishTransaction(IDBTransactionBackendImpl*);
private:
IDBTransactionCoordinator();
void processStartedTransactions();
// This map owns all transactions known to the coordinator.
HashMap<int, RefPtr<IDBTransactionBackendImpl> > m_transactions;
// Transactions in different states are grouped below.
ListHashSet<IDBTransactionBackendImpl* > m_startedTransactions;
HashSet<IDBTransactionBackendImpl* > m_runningTransactions;
int m_nextID;
};
} // namespace WebCore
#endif // ENABLE(INDEXED_DATABASE)
#endif // IDBTransactionCoordinator_h
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