/*

* Copyright (c) 2004-2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "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: 

* Implementation of the CDesSisDataProvider

*

*/

#include <e32std.h>

#include "dessisdataprovider.h"

#include "sisinstallerrors.h"

using namespace Swi;

EXPORT_C CDesDataProvider* CDesDataProvider::NewL(const TDesC8& aDes)

	{

	CDesDataProvider* self=CDesDataProvider::NewLC(aDes);

	CleanupStack::Pop(self);

	return self;

	}

EXPORT_C CDesDataProvider* CDesDataProvider::NewLC(const TDesC8& aDes)

	{

	CDesDataProvider* self=new(ELeave) CDesDataProvider(aDes);

	CleanupStack::PushL(self);

	return self;	

	}

CDesDataProvider::CDesDataProvider(const TDesC8& aDes)

	: iDes(aDes)

	{

	}

EXPORT_C CDesDataProvider::~CDesDataProvider()

	{

	}

// From MSisDataProvider

EXPORT_C TInt CDesDataProvider::Read(TDes8& aDes)

	{

	return Read(aDes, aDes.MaxSize());

	}

EXPORT_C TInt CDesDataProvider::Read(TDes8& aDes, TInt aLength)

	{

	if (aLength > aDes.MaxSize())

		{		

		return KErrOverflow;

		}

	TInt availableDataLength = 	iDes.Length() - iPos;

	TInt bytesToRead = aLength > availableDataLength ? availableDataLength : aLength;

	aDes.Copy(iDes.Mid(iPos, bytesToRead));

	iPos += bytesToRead;

	return KErrNone;

	}

EXPORT_C TInt CDesDataProvider::Seek(TSeek aMode, TInt64& aPos)

	{

	if (aPos < TInt64(KMinTInt32) || TInt64(KMaxTInt32) < aPos)

		{

		return KErrNotSupported;

		}

	TInt offset = I64INT(aPos);

	switch (aMode)

		{

		case ESeekStart:

			if ((offset < 0) || (offset >= iDes.Length()))

				{

				// Don't truncate offset as ESeekStart doesn't modify aPos

				return KErrArgument;

				}

			iPos = offset;

			break;

		case ESeekCurrent:

			if (offset >= 0)

				{	

				if (offset > (iDes.Length()-iPos))

					{

					iPos = iDes.Length();	

					}

				else

					{

					iPos += offset;

					}

				}

			else

				{

				if ((iPos+offset) < 0)

					{

					iPos = 0;

					}

				else

					{

					iPos += offset;

					}

				}

			// TInt64 has no assignment or construction from TInt32

			aPos = TInt(iPos);

			break;

		case ESeekEnd:

			if (offset > 0)

				{

				return KErrArgument;	

				}

			iPos = iDes.Length()+offset;

			if (iPos < 0)

				{

				iPos = 0;

				}

			aPos = TInt(iPos);

			break;

		case ESeekAddress:

			return KErrNotSupported;

		//Default Clause added as part of DEF100584			

		default:

    		return KErrArgument;

		}

	return KErrNone;

	}