/*

* Copyright (c) 2007-2008 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:  

*

*/

#include "hnxmlmodelcache.h"

#include "hnglobals.h"

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TUint32 HBufCHashCache( HBufC* const &  aBuf )

    {

    return DefaultHash::Des16(*aBuf);

    }

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TBool HBufCIdentCache( HBufC* const & aL, HBufC* const & aR )

    {

    return DefaultIdentity::Des16(*aL, *aR);

    }

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CHnXmlModelCache::CHnXmlModelCache() : iDocuments( &HBufCHashCache, 

        &HBufCIdentCache )

    {

    }

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void CHnXmlModelCache::ConstructL()

	{

	}

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void CHnXmlModelCache::RemoveUnused()

    {

    // remove unnecessary (oldest and unused) xml cached documents

    if(iDocuments.Count() > KXmlModelCacheMaxLength)

        {

        HBufC *suiteToRemove = iOrder[0];

        RXmlEngDocument* document = iDocuments.Find( suiteToRemove );

        document->Close();

        iDocuments.Remove(suiteToRemove);

        iOrder.Remove(0);

        delete suiteToRemove;

        }

    }

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TInt CHnXmlModelCache::AddL( const TDesC& aSuiteName, RXmlEngDocument& aDocument ) 

    {

    HBufC* key = aSuiteName.AllocLC();

    iDocuments.InsertL( key, aDocument );

    CleanupStack::Pop( key );

    iOrder.AppendL( key );

    RemoveUnused();

    return KErrNone;

    }

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TBool CHnXmlModelCache::IsCachedL( const TDesC& aSuiteName )

    {

    HBufC* buf = aSuiteName.AllocLC();

    const RXmlEngDocument* res = iDocuments.Find( buf );

    CleanupStack::PopAndDestroy( buf );

    if ( res )

        return ETrue;

    else

        return EFalse;

    }

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void CHnXmlModelCache::MoveToTopL( const TDesC & aSuiteName )

    {

    TInt pos( KErrNotFound );

    for ( TInt i(0); i < iOrder.Count(); i++ )

        {

        if ( !iOrder[i]->Compare( aSuiteName ) )

            {

            pos = i;

            break;

            }

        }

    // if document was found and is not the latest in the array 

    if ( pos != KErrNotFound && ( pos != iOrder.Count() - 1 ) )

        {

        HBufC *tmp = iOrder[ pos ];

        iOrder.Remove( pos );

        iOrder.AppendL( tmp );

        }

    }

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void CHnXmlModelCache::GetL( const TDesC& aSuiteName,

        RXmlEngDocument& aDocument )

    {

    HBufC* buf = aSuiteName.AllocLC();

    const RXmlEngDocument* res = iDocuments.Find( buf );

    MoveToTopL( aSuiteName );

    if ( res )

        {

        aDocument = *res;

        }

    CleanupStack::PopAndDestroy( buf );

    }

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CHnXmlModelCache* CHnXmlModelCache::NewLC()

    {

    CHnXmlModelCache* self = new (ELeave) CHnXmlModelCache();

    CleanupStack::PushL( self );

    self->ConstructL();

    return self;

    }

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CHnXmlModelCache* CHnXmlModelCache::NewL()

    {

    CHnXmlModelCache* self = CHnXmlModelCache::NewLC();

    CleanupStack::Pop( self );

    return self;

    }

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void CHnXmlModelCache::Reset()

    {

    THashMapIter<HBufC*, RXmlEngDocument> iter( iDocuments );

    while ( HBufC* const * ptr = iter.NextKey() )

        {

        RXmlEngDocument* currentDocument = iter.CurrentValue();

        currentDocument->Close();

        delete *ptr;

        }

    iDocuments.Close();

    // Names have already been destroyed when destroying iDocuments so

    // it is not necessay to destroy elements of the iOrder array. 

    iOrder.Close(); 

    }

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CHnXmlModelCache::~CHnXmlModelCache()

    {

    Reset();

    }