// 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:

// Name        : MessageReader.cpp

// Part of     : SigComp / dispatcher

// SigComp message reader

// Version     : 1.0

//

// INCLUDE FILES

#include "MessageReader.h"

#include "Sigcomp.h"

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

CMessageReader::CMessageReader(const TDesC8& aMessage,

                               TBool aStreamBasedProtocol) :

    iMessage(aMessage),

    iStreamBasedProtocol(aStreamBasedProtocol)

    {

    }

TInt CMessageReader::ReadByte(TUint& aByte)

    {

    if (iStreamBasedProtocol)

        {

        if (iQuoteBytes > 0)

            {

            if (iPos < iMessage.Length())

                {

                aByte = iMessage[iPos];

                iPos++;

                iQuoteBytes--;

                return KErrNone;

                }

            else

                {

                return KErrTooBig;

                }

            }

        else

            {

            if (iPos < iMessage.Length())

                {

                aByte = iMessage[iPos];

                iPos++;

                if (aByte == 0xff)

                    {

                    if (iPos < iMessage.Length())

                        {

                        aByte = iMessage[iPos];

                        iPos++;

                        if (aByte <= 0x7f)

                            {

                            iQuoteBytes = aByte;

                            aByte = 0xff;

                            return KErrNone;

                            }

                        else if (aByte == 0xff)

                            {

                            return KErrEof;

                            }

                        else    // aByte: 0x80-0xfe

                            {

                            return CSigComp::EDecompressionFailure;

                            }

                        }

                    else

                        {

                        return KErrTooBig;

                        }

                    }

                else

                    {

                    return KErrNone;

                    }

                }

            else

                {

                return KErrTooBig;

                }

            }

        }

    else

        {

        if (iPos < iMessage.Length())

            {

            aByte = iMessage[iPos];

            iPos++;

            return KErrNone;

            }

        else

            {

            return KErrTooBig;

            }

        }

    }

TInt CMessageReader::ReadBlock(TDes8& aBlock)

    {

    return ReadBlock(aBlock, aBlock.MaxLength());

    }

TInt CMessageReader::ReadBlock(TDes8& aBlock, TInt aLength)

    {

    if (iStreamBasedProtocol)

        {

        aBlock.SetLength(0);

        TInt i;

        TUint byte;

        for (i = 0; i < aLength; i++)

            {

            TInt retval = ReadByte(byte);

            if (retval == KErrNone)

                {

                aBlock.Append(byte);

                }

            else

                {

                return retval;

                }

            }

        return KErrNone;

        }

    else

        {

        TInt len = aLength;

        if ((iPos + len) > iMessage.Length())

            {

            len = iMessage.Length() - iPos;

            }

        aBlock.Copy(iMessage.Mid(iPos, len));

        iPos += len;

        if (len == aLength)

            {

            return KErrNone;

            }

        else

            {

            return KErrTooBig;

            }

        }

    }

TInt CMessageReader::Avail(TInt aLength)

    {

    if (iStreamBasedProtocol)

        {

        TInt quote = iQuoteBytes;

        TInt pos = iPos;

        TInt i;

        TUint byte;

        for (i = 0; i < aLength; i++)

            {

            TInt retval = ReadByte(byte);

            if (retval != KErrNone)

                {

                iQuoteBytes = quote;

                iPos = pos;

                return retval;

                }

            }

        iQuoteBytes = quote;

        iPos = pos;

        return KErrNone;

        }

    else

        {

        if ((iPos + aLength) <= iMessage.Length())

            {

            return KErrNone;

            }

        else

            {

            return KErrTooBig;

            }

        }

    }

TInt CMessageReader::SkipDelimiters(TUint aDelToSkip)

    {

    if (iStreamBasedProtocol)

        {

        TUint i;

        for (i = 0; i < aDelToSkip; i++)

            {

            if (iPos < iMessage.Length())

                {

                if (iMessage[iPos] == 0xff)

                    {

                    if ((iPos+1) < iMessage.Length())

                        {

                        if (iMessage[iPos+1] == 0xff)

                            {

                            iPos += 2;

                            }

                        else

                            {

                            return KErrNone;

                            }

                        }

                    else

                        {

                        return KErrTooBig;

                        }

                    }

                else

                    {

                    return KErrNone;

                    }

                }

            else

                {

                return KErrNone;

                }

            }

        return KErrNone;

        }

    else

        {

        return KErrNone;

        }

    }

TInt CMessageReader::Pos()

    {

    return iPos;

    }