// Copyright (c) 1996-2009 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:

// f32\sfat32\inc\sl_cache.inl

// 

//

/**

 @file

 @internalTechnology

*/

#ifndef SL_CACHE_INL

#define SL_CACHE_INL

/**

    @param  aPos media linear position

    @return ETrue if the aPos belongs to this page

*/

TBool CWTCachePage::PosCached(TInt64 aPos) const

    {

    return (iValid && aPos >= iStartPos && aPos < iStartPos+PageSize());

    }

/**

    Calculate data position within cache page relatively to the page beginning.

    @param  aPos media linear position

    @return data offset from the beginning of the page

*/

TUint32 CWTCachePage::PosInCachePage(TInt64 aPos) const 

    { 

    return ((TUint32)aPos - (TUint32)iStartPos) & (PageSize()-1);

    }

/**

    Obtain pointer to the data in the cache page by media inear position

    @param  aPos media linear position

    @return pointer to the data in page buffer

*/

TUint8* CWTCachePage::PtrInCachePage(TInt64 aPos) const 

    { 

    return (TUint8*)iData.Ptr() + PosInCachePage(aPos);

    }

/**

    @return cache page size in bytes

*/

TUint32 CWTCachePage::PageSize() const 

    {

    return iData.Size();

    }  

//---------------------------------------------------------------------------------------------------------------------------------

/**

    Just helper method to calculate cache page start position by given media pos.

    @param  aPos media linear position

    @return rounded-down and aligned position that is the beginning of the cache page

*/

TInt64  CMediaWTCache::CalcPageStartPos(TInt64 aPos) const 

    { 

    ASSERT(aPos >= iCacheBasePos);

    return (((aPos - iCacheBasePos) >> iPageSizeLog2) << iPageSizeLog2) + iCacheBasePos;

    }

/**

    @return cache page size

*/

TUint32 CMediaWTCache::PageSize() const 

    {

    return 1<<iPageSizeLog2;

    }

/**

    Set cache base position at aBasePos

    @param  aBasePos  base position of the cache pages. Affects pages alignment.

*/

void CMediaWTCache::SetCacheBasePos(TInt64 aBasePos)

    {

    iCacheBasePos = aBasePos;

    }

//---------------------------------------------------------------------------------------------------------------------------------

#endif //SL_CACHE_INL