// Copyright (c) 2003-2009 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:

//

#include "ShiftedFileStore.h"

/**

@internalComponent

CShiftedFileStore::OpenLC(RFs& aFs, const TDesC& aName, TUint aFileMode, TUint aFileOffset) method.

CFileStore::OpenL(RFs& aFs,const TDesC& aName,TUint aFileMode,const TFileStoreFactoryFunction aFactory[])

method was used as an origin for the method's source code.

*/

CShiftedFileStore* CShiftedFileStore::OpenLC(RFs& aFs, const TDesC& aName, TUint aFileMode, TUint aFileOffset)

	{

	RFile file;

	User::LeaveIfError(file.Open(aFs, aName, aFileMode));

	CShiftedFileStore* store = FromL(file, aFileOffset);

	CleanupStack::PushL(store);

	return store;

	}

/**

@internalComponent

CShiftedFileStore::FromL(RFile& aFile, TUint aFileOffset) method.

CFileStore::FromL(RFile& aFile,TFileStoreFactoryFunction aFunction) method was used as an origin

for the method's source code. The only difference is that RFileBuf::Attach is called with possibly

non-zero offset. The original implementation always calls RFileBuf::Attach with zero offset.

*/

CShiftedFileStore* CShiftedFileStore::FromL(RFile& aFile, TUint aFileOffset)

	{

	if (static_cast<TInt>(aFileOffset) < 0)

		User::Leave(KErrArgument);

	RFileBuf buf;

	buf.Attach(aFile, static_cast <TInt> (aFileOffset));

	buf.PushL();

	RReadStream stream(&buf);

	TCheckedUid chk;

	stream >> chk;

	CFileStore* store = (*KDirectFileStoreFactoryFunction)(buf, chk.UidType());

	if(store == NULL)

		User::Leave(KErrNotSupported);

	//CleanupStack::Pop(2) is called, because:

	//1) buf.PushL() - actually MStreamBuf::PushL() is called and it pushes buf 

	//                 into CleanupStack.

	//1) CFileStore* store = (*KDirectFileStoreFactoryFunction)(buf, chk.UidType()) -

	//                 FileStoreFactory::DirectLC() is called.

	CleanupStack::Pop(2);

	return static_cast <CShiftedFileStore*> (store);

	}

/**

@internalComponent

Constructor. Prevents compiler warnings.

Actually, CShiftedFileStore instance is newer created. CFileStore or CDirectFileStore

instance is created and downcasted to CShiftedFileStore. It is possible to do that:

CShiftedFileStore doesn't have data members at all.

*/

CShiftedFileStore::CShiftedFileStore(RFile& aFile) :

	CDirectFileStore(aFile)

	{

	}