/*

* Copyright (c) 2003 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 RUnicodeFile.

*      

*

*/

// INCLUDE FILES

#include "UnicodeFile.h"

// CONSTANTS

/// Little-endian Unicode file header.

LOCAL_D const TUint16 KLittleEndianUnicodeHeader = 0xFEFF;

// ================= MEMBER FUNCTIONS =======================

// ---------------------------------------------------------

// RUnicodeFile::Open

// ---------------------------------------------------------

//

TInt RUnicodeFile::Open( RFs& aFs, const TDesC& aName, TUint aFileMode )

    {

    if( aFileMode & EFileWrite )

        {

        // This supports only read access.

        User::Leave( KErrNotSupported );

        }

    TInt err = iFile.Open( aFs, aName, aFileMode );

    if ( !err )

        {

        // Check Unicode endianness.

        TUint c = 0;

        TRAPD( err, c = GetCharL() );

        if( !err )

            {

            if ( c != KLittleEndianUnicodeHeader )

                {

                err = KErrNotSupported;

                }

            }

        }

    if( err )

        {

        iFile.Close();

        }

    return err;

    }

// ---------------------------------------------------------

// RUnicodeFile::Replace

// ---------------------------------------------------------

//

TInt RUnicodeFile::ReplaceL( RFs& aFs, const TDesC& aName, TUint aFileMode )

    {

    if( aFileMode & EFileRead )

        {

        // This supports only write access.

        User::Leave( KErrNotSupported );

        }

    TInt err = iFile.Replace( aFs, aName, aFileMode );

    if ( !err )

        {

        // Write Unicode header.

        err = iFile.Write( TPtrC8( (TUint8*)&KLittleEndianUnicodeHeader, 2 ) );

        }

    if( err )

        {

        iFile.Close();

        }

    return err;

    }

// ---------------------------------------------------------

// RUnicodeFile::Close

// ---------------------------------------------------------

//

void RUnicodeFile::Close()

    {

    iFile.Close();

    }

// ---------------------------------------------------------

// RUnicodeFile::GetCharL

// ---------------------------------------------------------

//

TUint RUnicodeFile::GetCharL()

    {

    TUint c = 0;

    TPtr8 ptr( (TUint8*)(&c), 2 );

    User::LeaveIfError( iFile.Read( ptr, 2 ) );

    if( ptr.Length() == 0 )

        {

        // Nothing is read, successfully: this must be EOF.

        c = 0;

        }

    else if( ptr.Length() == 1 )

        {

        // Odd number of bytes in Unicode file?

        User::Leave( KErrCorrupt );

        }

    return c;

    }

// ---------------------------------------------------------

// RUnicodeFile::Write

// ---------------------------------------------------------

//

TInt RUnicodeFile::Write( const TDesC16& aDes )

    {

    return iFile.Write ( TPtrC8( (const TUint8*)aDes.Ptr(), aDes.Size() ) );

    }