// 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:

//

#ifndef __QOS_EXTENSION_H__

#define __QOS_EXTENSION_H__

/**

 * @file qos_extension.h 

 * This file defines the base class for QoS extensions that can be added to CQoSParameters.

 */

#include <e32std.h>

#include <in_sock.h>

//#include <networking/qosparameters.h>

/**

 * Base class for extension policies.

 *

 * @publishedPartner

 * @released

 */

class CExtensionBase : public CBase

{

public:

    IMPORT_C CExtensionBase();

    IMPORT_C ~CExtensionBase();

    /** 

    Extension must implement this function to allow qoslib to create 

    extensions.

    @publishedPartner

    @released

    @capability NetworkServices Restrict QoS operations in similar way as 

    normal socket operations.

    @leave If no memory is available.

    @return A pointer to extension object. 

    */

    virtual CExtensionBase* CreateL()=0;

    /** 

    Gets the type of the extension. 

    @publishedPartner

    @released

    @capability NetworkServices Restrict QoS operations in similar way as 

    normal socket operations.

    @return Extension type. 

    */

    inline TInt Type() const { return iType; }

    /** 

    Gets the extension data in a descriptor.

    The extension must implement this function to allow qoslib to fetch the 

    extension data.  

    @publishedPartner

    @released

    @capability NetworkServices Restrict QoS operations in similar way as 

    normal socket operations.

    @return Extension data. 

    */

    virtual TDesC8& Data()=0;

    /**

    Parses the extension data received as a parameter.

    The extension must implement this function to allow qoslib give the 

    extension data to the extension object.  

    @publishedPartner

    @released

    @capability NetworkServices Restrict QoS operations in similar way as 

    normal socket operations.

    @param aData Extension data.

    @return KErrNone, if aData contains a valid extension; otherwise, error 

    code. 

    */

    virtual TInt ParseMessage(const TDesC8& aData)=0;

    /**

    Copies aExtension into this object.

    The extension must implement this function to allow copying of 

    extensions.  

    @publishedPartner

    @released

    @capability NetworkServices Restrict QoS operations in similar way as 

    normal socket operations.

    @param aExtension Extension data.

    @return KErrNone, if copying succeeded; otherwise, error code. 

    */

    virtual TInt Copy(const CExtensionBase& aExtension)=0;

public:

    TSglQueLink iLink; //iLink needs to be accessible for setting offset!

protected:

    /** The extension type. */

    TInt iType;

    /** Buffer for extension data. */

    HBufC8* iData; 

    /** Pointer to next item in an extension queue. */

};

/** A typedef for a queue of extensions. */

typedef TSglQue<CExtensionBase> TQoSExtensionQueue;

/** A typedef for an iterator to a queue of extensions. */

typedef TSglQueIter<CExtensionBase> TQoSExtensionQueueIter;

#endif