/*

* Copyright (c) 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 "MemSpyDriverStreamReaderImp.h"

CMemSpyMemStreamReader::CMemSpyMemStreamReader( const TDesC8& aData )

    {

    iCurrent = aData.Ptr();

    iMax = iCurrent + aData.Length();

    }

void CMemSpyMemStreamReader::ConstructL()

    {

    }

TInt32 CMemSpyMemStreamReader::ReadInt32L()

    {

    TInt32 ret = 0;

    //

    const TInt size = sizeof( TInt32 );

    IsAvailableL( size );

    Mem::Copy( (TAny*) &ret, iCurrent, size );

    IncrementPos( size );

    //

    return ret;

    }

TUint32 CMemSpyMemStreamReader::ReadUint32L()

    {

    TUint32 ret = 0;

    //

    const TInt size = sizeof( TUint32 );

    IsAvailableL( size );

    Mem::Copy( (TAny*) &ret, iCurrent, size );

    IncrementPos( size );

    //

    return ret;

    }

void CMemSpyMemStreamReader::ReadL( TDes8& aDes )

    {

    const TInt length = ReadInt32L();

    // Need to check the remaining text is actually present...

    IsAvailableL( length );

    // Now read into client descriptor

    aDes.SetLength( length );

    if  ( length > 0 ) 

        {

        TUint8* dest = const_cast< TUint8* >( aDes.Ptr() );

        Mem::Copy( dest, iCurrent, length );

        }

    //

    IncrementPos( length );

    }

void CMemSpyMemStreamReader::ReadL( TDes16& aDes )

    {

    // The kernel driver only ever writes narrow descriptors.

    // However, we can expand them to be UCS2

    const TInt length = ReadInt32L();

    // Need to check the remaining text is actually present...

    IsAvailableL( length );

    // Set final length in descriptor

    aDes.SetLength( length );

    // Read each char

    TUint16* dest = const_cast< TUint16* >( aDes.Ptr() );

    for( TInt i=0; i<length; i++ )

        {

        *dest++ = *iCurrent++;

        }

    }

void CMemSpyMemStreamReader::IsAvailableL( TInt aRequired ) const

    {

    const TUint8* endPos = iCurrent + aRequired;

    if  ( endPos > iMax )

        {

        User::Leave( KErrOverflow );

        }

    }

void CMemSpyMemStreamReader::IncrementPos( TInt aAmount )

    {

    iCurrent += aAmount;

    }