// 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)

 	{

 	}