1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/os/kernelhwsrv/userlibandfileserver/fileserver/sfat32/sl_cache.inl	Fri Jun 15 03:10:57 2012 +0200
     1.3 @@ -0,0 +1,106 @@
     1.4 +// Copyright (c) 1996-2009 Nokia Corporation and/or its subsidiary(-ies).
     1.5 +// All rights reserved.
     1.6 +// This component and the accompanying materials are made available
     1.7 +// under the terms of the License "Eclipse Public License v1.0"
     1.8 +// which accompanies this distribution, and is available
     1.9 +// at the URL "http://www.eclipse.org/legal/epl-v10.html".
    1.10 +//
    1.11 +// Initial Contributors:
    1.12 +// Nokia Corporation - initial contribution.
    1.13 +//
    1.14 +// Contributors:
    1.15 +//
    1.16 +// Description:
    1.17 +// f32\sfat32\inc\sl_cache.inl
    1.18 +// 
    1.19 +//
    1.20 +
    1.21 +/**
    1.22 + @file
    1.23 + @internalTechnology
    1.24 +*/
    1.25 +
    1.26 +#ifndef SL_CACHE_INL
    1.27 +#define SL_CACHE_INL
    1.28 +
    1.29 +
    1.30 +/**
    1.31 +    @param  aPos media linear position
    1.32 +    @return ETrue if the aPos belongs to this page
    1.33 +*/
    1.34 +TBool CWTCachePage::PosCached(TInt64 aPos) const
    1.35 +    {
    1.36 +    return (iValid && aPos >= iStartPos && aPos < iStartPos+PageSize());
    1.37 +    }
    1.38 +
    1.39 +
    1.40 +/**
    1.41 +    Calculate data position within cache page relatively to the page beginning.
    1.42 +    @param  aPos media linear position
    1.43 +    @return data offset from the beginning of the page
    1.44 +*/
    1.45 +TUint32 CWTCachePage::PosInCachePage(TInt64 aPos) const 
    1.46 +    { 
    1.47 +    return ((TUint32)aPos - (TUint32)iStartPos) & (PageSize()-1);
    1.48 +    }
    1.49 +
    1.50 +/**
    1.51 +    Obtain pointer to the data in the cache page by media inear position
    1.52 +    @param  aPos media linear position
    1.53 +    @return pointer to the data in page buffer
    1.54 +*/
    1.55 +TUint8* CWTCachePage::PtrInCachePage(TInt64 aPos) const 
    1.56 +    { 
    1.57 +    return (TUint8*)iData.Ptr() + PosInCachePage(aPos);
    1.58 +    }
    1.59 +
    1.60 +/**
    1.61 +    @return cache page size in bytes
    1.62 +*/
    1.63 +TUint32 CWTCachePage::PageSize() const 
    1.64 +    {
    1.65 +    return iData.Size();
    1.66 +    }  
    1.67 +
    1.68 +//---------------------------------------------------------------------------------------------------------------------------------
    1.69 +
    1.70 +
    1.71 +/**
    1.72 +    Just helper method to calculate cache page start position by given media pos.
    1.73 +    @param  aPos media linear position
    1.74 +    @return rounded-down and aligned position that is the beginning of the cache page
    1.75 +*/
    1.76 +TInt64  CMediaWTCache::CalcPageStartPos(TInt64 aPos) const 
    1.77 +    { 
    1.78 +    ASSERT(aPos >= iCacheBasePos);
    1.79 +    return (((aPos - iCacheBasePos) >> iPageSizeLog2) << iPageSizeLog2) + iCacheBasePos;
    1.80 +    }
    1.81 +
    1.82 +/**
    1.83 +    @return cache page size
    1.84 +*/
    1.85 +TUint32 CMediaWTCache::PageSize() const 
    1.86 +    {
    1.87 +    return 1<<iPageSizeLog2;
    1.88 +    }
    1.89 +
    1.90 +
    1.91 +/**
    1.92 +    Set cache base position at aBasePos
    1.93 +    @param  aBasePos  base position of the cache pages. Affects pages alignment.
    1.94 +*/
    1.95 +void CMediaWTCache::SetCacheBasePos(TInt64 aBasePos)
    1.96 +    {
    1.97 +    iCacheBasePos = aBasePos;
    1.98 +    }
    1.99 +
   1.100 +
   1.101 +
   1.102 +//---------------------------------------------------------------------------------------------------------------------------------
   1.103 +
   1.104 +
   1.105 +#endif //SL_CACHE_INL
   1.106 +
   1.107 +
   1.108 +
   1.109 +