/*

* Copyright (c) 2007 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:    Ring buffer for storing packets from source.*

*/

#ifndef _CCRPACKETBUFFER_H

#define _CCRPACKETBUFFER_H

// INCLUDES

#include "MCRPacketSource.h"

#include "CCRPacketSinkBase.h"

#include <e32base.h>

#include <e32cmn.h>

// CONSTANTS

const TInt KStreamTypeBytePoint( 0 );

const TInt KStreamTypeBytesLength( 1 );

// MACROS

// None

// DATA TYPES

// None

// FORWARD DECLARATIONS

class CCRPacketSinkBase;

// CLASS DECLARATION

/**

*  Ring buffer where to store RTP packets.

*

*  @lib CommonRecordingEngine.lib

*  @since Series 60 3.0

*/

class CCRPacketBuffer : public CBase

    {

public: // Constructors and destructors

    /** 

    * Allocation method for buffer. 

    * @param aMaxPackets a maximum packets count in buffer.

    * @return buffer id.

    */

    static CCRPacketBuffer* NewL( const TInt aMaxPackets );

    /**

    * De-allocation method.

    */

    ~CCRPacketBuffer();

public: // New methods

    /**

    * Method for setting sink for buffer

    * @since Series 60 3.0

    * @param aSink is the sink to set

    * @return KErrNone if ok, otherwise system-wide error codes.

    */       

    TInt AddSink( CCRPacketSinkBase* aSink );

    /**

    * Method for adding a packet to buf. Succeeds always.

    * If memory allocation fails this silently fails.

    * @since Series 60 3.0

    * @param aStream a type of packet.

    * @param aHeader a pointer to packet header.

    * @param aPacket a pointer to packet payload.

    * @return none

    */

    void AddPacket( const MCRPacketSource::TCRPacketStreamId& aStream,

                    const TDesC8& aHeader,

                    const TDesC8& aPacket );

    /**

    * Method for adding a packet to buf.

    * If memory allocation fails this silently fails.

    * @since Series 60 3.0

    * @param aStream a type of packet.

    * @param aPacket is pointer to data that will be stored to buf.

    * @return none

    */

    void AddPacket( const MCRPacketSource::TCRPacketStreamId& aStream,

                    const TDesC8& aPacket );

    /**

    * Setter for buffer's flow control mode.

    * @since Series 60 3.0

    * @param aState a state to set.

    * @return none

    */

    void ContinousStream( const TBool aState );

    /**

    * Getter for buffer's flow control mode.

    * @since Series 60 3.0

    * @return true if continous stream,

              false if needs flow control.

    */

    TBool ContinousStream();

    /**

    * Setter for buffer's flow control state.

    * @since Series 60 3.0

    * @param aState a state to set.

    * @return none

    */

    void MoreComing( const TBool aState );

    /**

    * Getter for buffer's flow control state.

    * @since Series 60 3.0

    * @return more coming state.

    */

    TBool MoreComing();

    /**

    * Getter for stream of next packet.

    * @since Series 60 3.0

    * @param aId a id of requester.

    * @param a stream of the packet.

    * @return a book keeping index of sink.

    */

    TInt GetStream( const CCRStreamingSession::TCRSinkId& aId,

        		    MCRPacketSource::TCRPacketStreamId& aStreamId );

    /**

     * Getter for stream of packet in given offset.

     * @since Series 60 3.0

     * @param aId a id of requester.

     * @param a stream of the packet.

     * @return a book keeping index of sink.

     */

     TInt GetStream( const CCRStreamingSession::TCRSinkId& aId,

                     const TInt aOffset,

                     MCRPacketSource::TCRPacketStreamId& aStreamId );

    /**

    * Method for taking packet from a buffer.

    * @since Series 60 3.0

    * @param aId a id of requester.

    * @param aReturnedData is pointer where the data is read.

    *        NULL if nothing found.

    * @return none.

    */

    void GetPacket( const CCRStreamingSession::TCRSinkId& aId,

                    TPtr8& aReturnedData );

    /**

    * Method for taking packet from a buffer.

    * @since Series 60 3.0

    * @param aBookKeeping a book keeping index.

    * @param aReturnedData is pointer where the data is read.

    *        NULL if nothing found.

    * @return none.

    */

    void GetPacket( const TInt aBookKeeping,

                    TPtr8& aReturnedData );

    /**

    * Method for peeking at a packet in particular offset. This does not

    * set the packet to be removed from the buffer.

    * 

    * @since S60 v3.0

    * @param aId a id of requester.

    * @param aReturnedData is pointer where the data is read.

    *        NULL if nothing found.

    * @param aOffset offset of the packet to be peeked. If zero, the next

    *        packet in the buffer is peeked.

    */

    void PeekPacket( const CCRStreamingSession::TCRSinkId& aId,

                     TPtr8& aReturnedData,

                     const TInt aOffset );

    /**

    * Method for peeking at a packet in particular offset. This does not

    * set the packet to be removed from the buffer.

    * 

    * @since S60 v3.0

    * @param aBookKeeping a book keeping index.

    * @param aReturnedData is pointer where the data is read.

    *        NULL if nothing found.

    * @param aOffset offset of the packet to be peeked. If zero, the next

    *        packet in the buffer is peeked.

    */

    void PeekPacket( const TInt aBookKeeping,

                     TPtr8& aReturnedData, 

                     const TInt aOffset );

    /**

    * Method for asking how much packets there are in buf for certain sink.

    * @since Series 60 3.0

    * @param aId a id of requester.

    * @return number of packets in buffer.

    */       

    TInt PacketsCount( const CCRStreamingSession::TCRSinkId& aId ); 

    /**

    * Method for asking how much packets there are in buf in any sink.

    * @since Series 60 3.0

    * @param none.

    * @return minimum number of packets in buffer.

    */       

    TInt PacketsMinCount(); 

    /**

    * Method for removing a sink.

    * @since Series 60 3.0

    * @param aSink is the sink to delete

    * @return number of sinks remaining

    */       

    TInt RemoveSink( CCRPacketSinkBase* aSink );

    /**

    * Method for handle buffer wrapping.

    * @since Series 60 3.0

    * @return None.

    */       

    void HandleBufferSize();

    /**

    * Method for handle buffer size adjust.

    * @since Series 60 3.0

    * @return None.

    */       

    void AdjustBuffer();

    /**

    * Method for handle buffer resetting.

    * @since Series 60 3.0

    * @return None.

    */       

    void ResetBuffer();

private: // Constructors and destructor

    /**

    * Second pat of construction 

    */

    void ConstructL();

    /**

    * Default constructor is private.

    * @param aMaxPackets a maximum packets count in buffer.

    */

    CCRPacketBuffer( const TInt aMaxPackets );

private: // New methods

    /**

    * Method for handling maximum packets in buffer.

    * @since Series 60 3.0

    * @param none.

    * @return none.

    */

    void VerifyRoom();

    /**

    * Method for taking book keeping index from sink id.

    * @since Series 60 3.0

    * @param aId a id of requester.

    * @return a book keeping index of sink.

    */

    TInt GetBookKeeping( const CCRStreamingSession::TCRSinkId& aId );

    /**

    * Method for taking book keeping index from sink id.

    * @since Series 60 3.0

    * @param aBookKeeping a book keeping index.

    * @return an buffer index base on sink.

    */

    TInt GetBufferIndex( const TInt aBookKeeping );

    /**

    * Method for update book keeping of the packets.

    * @since Series 60 3.0

    * @param aDataLength a data length of packet.

    * @return None.

    */       

    void PacketToBookKeeping();

private: // Data types

    // Book keeping array

    class SBookKeeping 

        {

    public: // Data

        /**

        * Sink id.

        */

        CCRStreamingSession::TCRSinkId iId;

        /**

        * Buffer index.

        */

        TInt iIndex;

        };

private: // Data

    /**

    * Maximum memory usage.

    */

    const TInt iMaxPackets;

    /**

    * Flow control mode.

    */

    TBool iContinousStream;

    /**

    * Flow control state.

    */

    TBool iMoreComing;

    /**

    * Buffer to keep packets.

    */

    RPointerArray<HBufC8> iBuffer;

    /**

    * Keeps track of point of each user.

    */

    RArray<SBookKeeping> iBookKeeping; 

    /**

    * Zero or more packet sinks that are fed via this buffer.

    */

    RPointerArray<CCRPacketSinkBase> iSinkArray;

    };

#endif // _CCRPACKETBUFFER_H