/*

* Copyright (c) 2006-2008 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:  

*

*/

#ifndef M_NCDDATABASESTORAGE_H

#define M_NCDDATABASESTORAGE_H

#include <e32base.h>

#include <d32dbms.h>

class MNcdDatabaseStorage;

class MNcdStorageItem;

class RNcdDatabaseItems;

/**

 * Interface for database storages

 * @ Improve comments

 */

class MNcdDatabaseStorage

{

public:

    /**

     * Database size information

     */

    typedef RDbDatabase::TSize TNcdDatabaseSize;

public: 

    /**

     * Returns ponter to storage item. If storage item doesn't exist

     * it is created. Ownerhip of the storage item is not transferred

     * to caller.

     */

    virtual MNcdStorageItem* StorageItemL( const TDesC& aUid, TInt aType ) = 0;

    /**

     * Gets all storage items from storage. This method doens't create

     * new items to storage but returns all items being currently stored

     * to it.

     *

     * @param aItems An array where to storage items will be added.

     */

    virtual void StorageItemsL( RPointerArray<MNcdStorageItem>& aItems ) = 0;

    virtual void RemoveItemsL( 

        const RArray<RNcdDatabaseItems>& aDoNotRemoveItems ) = 0;

    /**

     * Begins transaction into storage.

     */

    virtual void Begin() = 0;

    /**

     * Commits changes to storage.

     */

    virtual void CommitL() = 0;

    /**

     * Discards changes and restores storage to state it was before

     * transaction was started.

     */

    virtual void Rollback() = 0;

    /**

     * Ensures that given storage item exists in storage.

     *

     * NOTE: It is possible that storage item is created and exists

     * but it is not stored to storage.

     *

     * @param aStorageItem The item to be checked

     * @return Boolean value indicating whether the item exsists in

     * storage.

     */

    virtual TBool ItemExistsInStorageL( MNcdStorageItem& aStorageItem ) = 0;

    /**

     * Ensures that given storage item exists in storage.

     *

     * NOTE: It is possible that storage item is created and exists

     * but it is not stored to storage.

     *

     * @param aUid Uid of the item to be checked

     * @param aType Type of the item to be checked

     * @return Boolean value indicating whether the item exsists in

     * storage.

     */

    virtual TBool ItemExistsInStorageL( const TDesC& aUid, TInt aType ) = 0;

    /**

     * Storage UID getter

     * @return Storage UID

     */

    virtual const TDesC& Uid() const = 0;

    /**

     * Database size getter

     */

    virtual TNcdDatabaseSize Size() const = 0;

    /**

     * Commits and compacts the db

     */

    virtual void Compact() = 0;

protected:

    virtual ~MNcdDatabaseStorage()

        {

        }

};

#endif // M_NCDDATABASESTORAGE_H