/*

* Copyright (c) 2006 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:  Implementation of CHttpCacheFileWriteHandler

*

*/

#ifndef CHTTPCACHEFILEWRITEHANDLER_H

#define CHTTPCACHEFILEWRITEHANDLER_H

//  INCLUDES

#include <e32base.h>

#include <f32file.h>

#include "HttpCacheHandler.h"

#include "HttpCacheEntry.h"

#include "MemoryManager.h"

// CONSTANTS

// MACROS

// DATA TYPES

// FUNCTION PROTOTYPES

class CAsyncFileWriter;

class CHttpCacheWriteTimeout;

// FORWARD DECLARATIONS

// CLASS DECLARATION

/**

*

*  @lib

*  @since 5.0

*/

NONSHARABLE_CLASS(CHttpCacheFileWriteHandler) : public CActive, public MMemoryCollector, public MHttpCacheEntryDeleteObserver

    {

    public:  // Constructors and destructor

        /**

        * Two-phased constructor.

        * @since 5.0

        * @param

        * @param

        * @return CacheFileWriteHandler object.

        */

        static CHttpCacheFileWriteHandler* NewL(CHttpCacheHandler* aManager, CHttpCacheStreamHandler* aStreamHandler, RFs& aRfs, const THttpCachePostponeParameters& aParams);

        /**

        * Destructor.

        */

        virtual ~CHttpCacheFileWriteHandler();

    public: // From MMemoryCollector

        /**

        * Collect free memory, this function is called when allocation from

        * System heap fails

        * @since 3.1

        * @param amount of memory needs to be collected

        * @return amount of memory collected

        */

        virtual TUint Collect(TUint aRequired);

        /**

        * restore the entity controlled memory collector when there is enough memory

        * System heap fails

        * @since 3.1

        * @param

        * @return

        */

        virtual void Restore();

        /**

        * Priority of this collector, 0 - lowest, 10 - highest;

        * the lower the priority, the earlier this collector is executed.

        * @since 3.1

        * @param

        * @return

        */

        virtual TOOMPriority Priority();

        /**

         *

         * @since 7.1

         * @param

         * @return

         */

        TBool IsCacheEntryPostponed(const CHttpCacheEntry* aEntry);

    public: // from MHttpCacheEntryDeleteObserver

        virtual void EntryDeleted(CHttpCacheEntry *aEntry); 

    public: // new functions

        enum TAddStatus {

            EAddedOk,

            EBodySmallerThanThreshold,

            ENotEnoughFreeMemory,

            ECheckReturn

        };

        /**

         * Add a cache entry to write out when possible

         *

         */

        TInt AddEntry(TAddStatus& aAddStatus, CHttpCacheEntry *aEntry);

        /**

         * Remove a stream entry from the list

         */

        CHttpCacheEntry* RemoveEntry(CHttpCacheEntry *aEntry);

        /**

         * Remove all stream entries from the list

         */

        void RemoveAll();

        /**

         * Emergency method if memory is short - write everything

         * to disk *now* and wait for it. Or maybe just dump it all

         * and delete the headers...

         */

        void DumpAllObjects();

        /**

         * Signal called by the timer callback to indicate that we

         * should begin writing out the cached data.

         */

        void BeginWriting();

    private:

        /**

        * Construct.

        * @since 5.0

        * @param

        * @param

        * @return CacheFileWriteHandler object.

        */

        CHttpCacheFileWriteHandler(CHttpCacheHandler* aHandler, CHttpCacheStreamHandler* aStreamHandler, RFs& aRfs);

        /**

        * By default Symbian 2nd phase constructor is private.

        */

        void ConstructL(const THttpCachePostponeParameters& aParams);

        /**

         * from CActive

         */

        void DoCancel();

        /**

         * from CActive

         */

        void RunL();

        void ContinueFlushing();

        void OutputQueueContentToDebug();

        // sort by size function for arrays of CHttpCacheEntry objects.

        static TInt CompareHttpCacheEntrySize( const CHttpCacheEntry& aFirst, const CHttpCacheEntry& aSecond );

        void CollectMemory( TUint aRequired );

        /**

         * Callback function for timer to activate writing.

         */

        static TInt WriteTimeout(TAny* aParam);

    private:    // Data

        CHttpCacheHandler*                  iCacheHandler;

        CHttpCacheStreamHandler*            iCacheStreamHandler;

        TInt                                iFreeRamThreshold;

        TInt                                iImmediateWriteThreshold;

        TBool                               iLowMemoryState;

        RFs                                 iFs;

        CHttpCacheWriteTimeout*             iWaitTimer;

        // objects in this array are not owned.

        RPointerArray<CHttpCacheEntry>      iObjectQueue;

        // contains a pointer to the object that flush was called for

        CHttpCacheEntry*                    iObjectFlushing;

    };

#endif      // CHttpCacheFileWriteHandler_H

// End of File