/*

* Copyright (c) 2005-2009 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          : MSigCompController.h

* Part of       : ConnectionMgr

* Version       : SIP/4.0 

*

*/

/**

 @internalComponent

*/

#ifndef __MSIGCOMPCONTROLLER_H__

#define __MSIGCOMPCONTROLLER_H__

#include <in_sock.h>

class CSIPRequest;

class CSIPResponse;

class TSIPTransportParams;

/**

 * Interface class for sigcomp controller

 */

class MSigCompController 

	{

	public:

    /**

     * Destructor.

	 */

    virtual ~MSigCompController () { };

    /**

     * Checks if signalling compression is installed.

     *

     * @returns ETrue if installed, EFalse otherwise.

	 */

    virtual TBool IsSupported () const = 0;

    /**

     * After calling this function Connection Mgr always uses

     * signalling compression for requests sent with compartmentId

     * returned by this function.      

     * Multiple users can share a compression to one host:

     * In sending phase remote inetaddr and compartmentid are mapped together.

     * If some other compartmentid has already same remote destination address

     * mapped with it, ids share the same compartment.

     *

     * @returns compartmentId

	 */

    virtual TUint32 CreateCompartmentL (TUint32 aIapId) = 0;

    /**

     * Removes compression for passed compartmentId.

     * If no compression for the host was found, the function silently returns.

	 */

    virtual void RemoveCompartment (TUint32 aCompartmentId) = 0;

	/**

	 * The function encodes the Request and compresses 

	 * it if there is compartment matching compartmentId. After calling

	 * this function, next-hop address is mapped with compartmentId.

	 * Leaves with a system wide error if encoding or compressing fails.

	 * 

	 * @param aTransportParams contains compartmentId and iapId

	 *

	 * @param aRequest a request to encode and compress	

	 *			

	 * @param aAddress	A remote destination address

	 *					

	 * @returns encoded data, the ownership is transferred

	 */

	virtual CBufBase* EncodeL (const TSIPTransportParams& aTransportParams,

	                           CSIPRequest& aRequest,

                               const TInetAddr& aAddress,

							   TBool aStreambasedProtocol,

							   TBool& aCompressed) = 0;

	/**

	 * The function encodes the Response and compresses 

     * it if there is compartment matching compartmentId. After calling

	 * this function, next-hop address is mapped with compartmentId.

	 * Leaves with a system wide error if encoding or compressing fails.

	 * 

	 * @param aTransportParams contains compartmentId and iapId

	 *

	 * @param aResponse a response to encode and compress	

	 *				

	 * @param aAddress	A remote destination address					

	 * 

	 * @returns encoded data, the ownership is transferred

	 */

	virtual CBufBase* EncodeL (const TSIPTransportParams& aTransportParams,

	                           CSIPResponse& aResponse,

                               const TInetAddr& aAddress,

							   TBool aStreambasedProtocol,

							   TBool& aCompressed) = 0;

	/**

	 * Checks if the message contains the delimeter indicating SigComp

	 * message end. This function must be used only with stream-based

	 * transports, otherwise it will always return EFalse.

	 *

	 * @pre IsSigCompMsg()==ETrue

	 *

	 * @returns ETrue is the SigComp message is complete, EFalse otherwise

	 */

	virtual TBool IsCompleteSigCompMessageL (const TDesC8& aMessage) const = 0;

	/**

	 * Checks if the first byte contains bit pattern indicating the start

	 * of the SigComp message. Function examines only the first byte.

	 *

	 * @returns ETrue if the first byte indicates the start of the SigComp message,

	 *          EFalse otherwise

	 */

	virtual TBool IsSigCompMsg (const TDesC8& aMessage) const = 0;

  	/**

	 * Decompress the message; leaves on failure. 

	 * Leaves with a system wide error decompressing fails.

	 * The function expects the client to provide complete SigComp message.

	 *

	 * @pre IsSigCompMsg()==ETrue

	 * 

	 * @param aMessage a message to decompress. The message must start with SigComp specific

	 *                 delimeter and end with SigComp specific delimeter

	 *

	 * @param aBytesConsumed on return will contain the number of bytes consumed by the decompression

	 *                       from the original message 

	 * @returns decompressed message, the ownership is transferred

	 */

	virtual CBufBase* DecompressL (const TDesC8& aMessage,

                                   TUint& aBytesConsumed,

                                   TBool aIsStreamBased) = 0;

	/**

	 * The function returns count of compartments

	 *

	 * @returns count of compartments

	 */

	virtual TInt CompartmentCount () = 0;

	/**

     * If the compartment has been previously used for decompressing,

     * resets the compartment. If not, deletes the compartment. 

     *

     * @param aCompartmentId the IAP for which the sending failed

     *

     */

	virtual void SendFailedL (TUint32 aCompartmentId) = 0;

	/**

	 * Allows the state of the decompressed message to be saved; leaves on failure.

	 * 

	 * @param aAddress	A remote destination address					

	 * @param aIapId	A iap id

	 */

	virtual void AllowL(const TInetAddr& aAddress, TUint32 aIapId) = 0;

	/**

	 * Denies the state of the message to be saved.

	 */

	virtual void Deny() = 0;

    };

#endif // end of __MSIGCOMPCONTROLLER_H__