/** @file

* Copyright (c) 2005-2006 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:  CUpnpHttpFileTransferReader is a class responsible for 

*                   asynchronous reading from socket owned by CUpnpTcpSession.

*

*/

#ifndef C_CUPNPHTTPFILETRANSFERREADER_H

#define C_CUPNPHTTPFILETRANSFERREADER_H

#include <e32base.h>

#include <in_sock.h>

#include "upnpnotifytimer.h"

//constants

static const TInt KMaxRetryErrors = 5;

static const TInt KRetryWaitTime = 1000000;

static const TInt KTwoSec = 2000000;

static const TInt KOneSec = 1000000;

//FORWARD DECLARATIONS

class CUpnpTcpSession;

class CUpnpHttpFileTransferBuffer;

class CUpnpHttpFileAccess;

/**

 *  CUpnpHttpFileTransferReader is responsible for asynchronous reading.

 *  Reader starta reading in asynchronous mode. Issues reading and then waits 

 *  for the operation to be completed. When it is completed then received

 *  data is forwarded to upper layer - CUpnpTcpSession and the new read 

 *  operation is issues. This continues in loop until the Cancel() is invoked

 *  or object is destroyed.

 *  @lib DLNAWebServer.lib

 *  @since Series60 3.2

 */

NONSHARABLE_CLASS (CUpnpHttpFileTransferReader) : public CActive, MUpnpNotifyTimerObserver

    {

public:

    /**

    * CUpnpHttpFileTransferReader factory method.

    * @since Series60 3.2

    * @param aSession session that runs and supervises reader.

    * @param aSocket socket from which data will be read.

    * @param aPriority priority with which the reader will be working.

    * @param aReadPortion - size of the buffer to read from the socket

    * @param aBufferSize - the buffer size

    * @return new CUpnpHttpFileTransferReader object's instance.

    */

    static CUpnpHttpFileTransferReader* NewL( CUpnpTcpSession& aSession,

                                        RSocket& aSocket,

                                        TThreadPriority aPriority,                                        

                                        TInt aReadPortion,

                                        TInt aBufferSize);

    /**

    * Virtual destructor.

    * @since Series60 3.2

    */                             

    virtual ~CUpnpHttpFileTransferReader();

    /**

    * Appends first portion of data to the buffer.

    * @since Series60 3.2

    */    

    void AppendL(const TDesC8& aBeginning);

    /**

    * Calculates the buffer size as exponent of 2

    * and proper for read portions

    * @since Series60 3.2

    */    

    static TInt CalculateBufferSize(TInt aReadPortion, TInt aBufferSize);            

    /**

    * Starts reading in asynchronous mode.

    * @since Series60 3.2

    */

    virtual void StartL();

    /**

    * Cancel the timers

    * @since Series60 3.2

    */

    void CancelTimers();

    /**

    * Resets some member values to start reading data

    * @since Series60 3.2

    */

    virtual void Reset();

    /**

    * Checks if the reader is started meaning in use

    * @since Series60 3.2

    * @return TBool

    */

    TBool Activated();

    /**

    * Sets the state of the reader to activated

    * @since Series60 3.2    

    * @param state - ETrue/EFalse

    */

    void SetActivated(TBool aValue);

protected: // Functions from CActive

    /**

    * Cancels issued reading request.

    * Standard active object function

    * @since Series60 3.2

    */

    void DoCancel();

     /**

    * Function called when the read request is finished.

    * Standard active object function

    * @since Series60 3.2

    */

    virtual void RunL();

    /**

    * Trap RunL leaves

    * Standard active object function

    * @since Series60 3.2

    */

    TInt RunError( TInt aError );

	// Constructors and destructors

    /**

    * CUpnpHttpFileTransferReader constructor.

    * @since Series60 3.2

    * @param aSession session that runs and supervises reader.

    * @param aSocket socket from which data will be read.

    * @param aPriority priority with which the reader will be working.

    * @param aReadPortion - size of the buffer to read from the socket

    * @param aBufferSize - the buffer size

    */

    CUpnpHttpFileTransferReader( CUpnpTcpSession& aSession,

                           RSocket& aSocket,

                           TThreadPriority aPriority,

                           TInt aReadPortion,

                           TInt aBufferSize);

protected: // New functions

    /**

    * Issues reading in asynchronous mode.

    * @since Series60 3.2

    */

    void IssueRead();

    /**

    * Callback function for timer expirations.

    * @since Series60 2.6

    * @param aTimer Timer that has expired.

    **/

	void TimerEventL( CUpnpNotifyTimer* /*aTimer*/ );

    /**

    * Starts the cancel timer.

    * @since Series60 3.2

    */

    void StartCancelTimer();

	/**

    * Base constructor to be used also in derived classes.

    * @since Series60 3.2

    */

    void BaseConstructL();

    /**

    * Initiates the buffer

    * @since Series60 3.2      

    */

    void InitiateBufferL();

	/**

    * Remaing number of bytes to read.

    * @since Series60 3.2    

    * @return TInt

    */

    virtual TInt ReadBufferSize();   

    /**

    * Handles buffer of data

    * @since Series60 3.2    

    * @return TBool

    */

    virtual TBool HandleL();   

    /**

    * Handles leave from RunL

    * @since Series60 3.2    

    * @param aError

    */

    void HandleError();   

    /**

    * Finish the session

    * @since Series60 3.2

    */

    virtual void Finish();  

    /**

    * Reads from socket

    * @since Series60 3.2    

    */

    virtual void ReadFromSocket();

    /**

    * Remaing number of bytes to read.

    * @since Series60 3.2    

    * @return TInt

    */

    virtual TInt RemainingBytes();

    /**

    * Returns bytes to be read unless FIN received, then returns 0

    * @since Series60 3.2    

    * @return TInt

    */

    TInt TcpFinFoundRemainingBytes();

    /**

    * Returns how many bytes will still fit into the buffer

    * @since Series60 3.2    

    * @return TInt

    */

    TInt AvailableSpace();

    /**

    * If content length is less than single buffer size

    * transaction is completed and session is closed

    * @since Series60 3.2    

    * @return TInt

    */    

    void HandleOneBufferShortTransferL();

protected: // Data

    //Socket from which the data will be read, not owned.    

    RSocket& iSocket;   

    // Reference to session that owns this reader.   

    CUpnpTcpSession& iSession;

    //Pointer that points to receiving buffer.

    TPtr8 iReceivePtr;       

    // Buffer that is used to receive data to session.   

    RBuf8 iCacheBuffer;

    // Read buffer size

    TInt iReadBufferSize;

    //size of buffered data

    TInt iBufferSize;  	

    //processing has finished

    TInt iIsFinished;

    //whether upload reader is activated

    TBool iIsActivated;

    /**

    * Timer used for retry process.

    */

    CUpnpNotifyTimer *iRetryTimer;

    /**

    * Timer used for cancel reciving process.

    */

    CUpnpNotifyTimer *iCancelTimer;

    /**

    * Variable indicating when the cancel was called from cancel timer.

    */

    TBool iCancelFromTimer;

    /**

    * Count of reading errors.

    */

    TInt iRetryErrorCount;

    //length of data read from socket

    TSockXfrLength iLen;

    };

#endif // C_CUPNPHTTPFILETRANSFERREADER_H

// End Of File