/*
 * Copyright (C) 2008, 2009, 2010 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:
 * 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 INC. ``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 INC. 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.
 */

#ifndef StorageAreaSync_h
#define StorageAreaSync_h

#if ENABLE(DOM_STORAGE)

#include "SQLiteDatabase.h"
#include "Timer.h"
#include <wtf/HashMap.h>
#include <wtf/text/StringHash.h>

namespace WebCore {

    class Frame;
    class StorageAreaImpl;
    class StorageSyncManager;

    class StorageAreaSync : public RefCounted<StorageAreaSync> {
    public:
        static PassRefPtr<StorageAreaSync> create(PassRefPtr<StorageSyncManager>, PassRefPtr<StorageAreaImpl>, const String& databaseIdentifier);
        ~StorageAreaSync();

        void scheduleFinalSync();
        void blockUntilImportComplete();

        void scheduleItemForSync(const String& key, const String& value);
        void scheduleClear();
        void scheduleCloseDatabase();

        void scheduleSync();

    private:
        StorageAreaSync(PassRefPtr<StorageSyncManager>, PassRefPtr<StorageAreaImpl>, const String& databaseIdentifier);

        void dispatchStorageEvent(const String& key, const String& oldValue, const String& newValue, Frame* sourceFrame);

        Timer<StorageAreaSync> m_syncTimer;
        HashMap<String, String> m_changedItems;
        bool m_itemsCleared;

        bool m_finalSyncScheduled;

        RefPtr<StorageAreaImpl> m_storageArea;
        RefPtr<StorageSyncManager> m_syncManager;

        // The database handle will only ever be opened and used on the background thread.
        SQLiteDatabase m_database;

    // The following members are subject to thread synchronization issues.
    public:
        // Called from the background thread
        void performImport();
        void performSync();
        void deleteEmptyDatabase();

    private:
        enum OpenDatabaseParamType {
          CreateIfNonExistent,
          SkipIfNonExistent
        };

        void syncTimerFired(Timer<StorageAreaSync>*);
        void openDatabase(OpenDatabaseParamType openingStrategy);
        void sync(bool clearItems, const HashMap<String, String>& items);

        const String m_databaseIdentifier;

        Mutex m_syncLock;
        HashMap<String, String> m_itemsPendingSync;
        bool m_clearItemsWhileSyncing;
        bool m_syncScheduled;
        bool m_syncInProgress;
        bool m_databaseOpenFailed;
        
        bool m_syncCloseDatabase;

        mutable Mutex m_importLock;
        mutable ThreadCondition m_importCondition;
        mutable bool m_importComplete;
        void markImported();
        void migrateItemTableIfNeeded();
    };

} // namespace WebCore

#endif // ENABLE(DOM_STORAGE)

#endif // StorageAreaSync_h
