diff -r 000000000000 -r bde4ae8d615e os/kernelhwsrv/userlibandfileserver/fileserver/sfat/ram_fat_table.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/os/kernelhwsrv/userlibandfileserver/fileserver/sfat/ram_fat_table.cpp	Fri Jun 15 03:10:57 2012 +0200
@@ -0,0 +1,485 @@
+// 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\sfat\ram_fat_table.cpp
+// FAT16 File Allocation Table classes implementation for the RAM media
+// 
+//
+
+/**
+ @file
+ @internalTechnology
+*/
+
+//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+//!!
+//!! WARNING!! DO NOT edit this file !! '\sfat' component is obsolete and is not being used. '\sfat32'replaces it
+//!!
+//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+
+#include "sl_std.h"
+#include "sl_fatcache.h"
+#include "fat_table.h"
+
+
+//#######################################################################################################################################
+//#     CRamFatTable class implementation 
+//#######################################################################################################################################
+
+/**
+Constructor, the RamFatTable allows disk compression by redirecting the FAT
+
+@param aOwner Owning mount.
+*/
+CRamFatTable::CRamFatTable(CFatMountCB& aOwner)
+             :CFatTable(aOwner)
+    {
+    iFatTablePos=aOwner.FirstFatSector()<<aOwner.SectorSizeLog2();
+    iIndirectionTablePos=iFatTablePos+aOwner.FatSizeInBytes();
+    }
+
+/** factory method */
+CRamFatTable* CRamFatTable::NewL(CFatMountCB& aOwner)
+{
+    __PRINT1(_L("CRamFatTable::NewL() drv:%d"),aOwner.DriveNumber());
+
+    CRamFatTable* pSelf = new (ELeave) CRamFatTable(aOwner);
+
+    CleanupStack::PushL(pSelf);
+    pSelf->InitializeL();
+    CleanupStack::Pop();
+
+    return pSelf;
+}
+
+void CRamFatTable::InitializeL() 
+{
+    CFatTable::InitializeL();
+
+    ASSERT(iMediaAtt & KMediaAttVariableSize);
+
+    iFatTablePos=iOwner->FirstFatSector()<<iOwner->SectorSizeLog2();
+    iIndirectionTablePos=iFatTablePos+iOwner->FatSizeInBytes();
+
+    //-- set RAM disk base
+    TLocalDriveCapsV2 caps;
+    TPckg<TLocalDriveCapsV2> capsPckg(caps);
+    User::LeaveIfError(iOwner->LocalDrive()->Caps(capsPckg));
+  
+    iRamDiskBase = caps.iBaseAddress; 
+}
+
+/**
+    Remount the FAT table. This method call means that the media parameters wasn't changed, 
+    otherwise CFatMountCB::DoReMountL() would reject it. 
+    Just do some re-initialisation work.
+*/
+void CRamFatTable::ReMountL()
+{
+    //-- re-initialise, actually
+    ASSERT(iMediaAtt & KMediaAttVariableSize);
+    ASSERT(FatType() == EFat16);
+
+    iFatTablePos=iOwner->FirstFatSector()<<iOwner->SectorSizeLog2();
+    iIndirectionTablePos=iFatTablePos+iOwner->FatSizeInBytes();
+
+    //-- set RAM disk base
+    TLocalDriveCapsV2 caps;
+    TPckg<TLocalDriveCapsV2> capsPckg(caps);
+    User::LeaveIfError(iOwner->LocalDrive()->Caps(capsPckg));
+  
+    iRamDiskBase = caps.iBaseAddress; 
+}
+
+
+/**
+Return the start address of the Ram Drive
+
+@return start address of the Ram Drive 
+*/
+TUint8 *CRamFatTable::RamDiskBase() const
+    {
+    return(iRamDiskBase);
+    }
+
+
+/**
+Allocate a new cluster number
+
+@return New cluster number
+*/
+TInt CRamFatTable::AllocateClusterNumber()
+    {
+    return(iOwner->MaxClusterNumber()-NumberOfFreeClusters());
+    }
+
+/**
+Write a value to the FAT (indirection table) 
+
+@param aFatIndex Cluster to write to
+@param aValue value to write to Fat
+@leave 
+*/
+void CRamFatTable::WriteL(TUint32 aFatIndex, TUint32 aValue)
+    {
+    //__PRINT(_L("CRamFatTable::WriteL"));
+
+    __ASSERT_ALWAYS(aFatIndex>=2 && (aValue>=2 || aValue==0) && aValue<=0xFFFF,User::Leave(KErrCorrupt));
+    TUint32 indirectCluster=aFatIndex;
+    TUint32 indirectClusterNewVal=0;
+    ReadIndirectionTable(indirectCluster);
+//  If value in indirection table!=0 we assume we have already written to the indirection table
+//  So just update the FAT table
+    if (indirectCluster!=0 && aValue!=0)
+        {
+        WriteFatTable(aFatIndex,aValue);
+        return;
+        }
+//  If value in indirection table is 0, we haven't written to it yet, though the memory has
+//  already been allocated by the EnlargeL() function
+    if (indirectCluster==0 && aValue!=0) // Assumes memory has already been allocated
+        indirectClusterNewVal=AllocateClusterNumber();
+//  Write aValue into aFaxIndex and indirectClusterNewVal into the corresponding position
+//  in the indirection table    
+    WriteFatTable(aFatIndex,aValue,indirectClusterNewVal);
+    }   
+
+/**
+Read the value of a cluster in the Fat
+
+@param aFatIndex A cluster to read
+@leave 
+@return The cluster value read
+*/
+
+TUint32 CRamFatTable::ReadL(TUint32 aFatIndex) const
+    {
+    __ASSERT_ALWAYS(aFatIndex>=KFatFirstSearchCluster,User::Leave(KErrCorrupt));
+    TUint clusterVal=*(TUint16*)(RamDiskBase()+PosInBytes(aFatIndex)+iFatTablePos);
+    return(clusterVal);
+    }
+
+/**
+Write a value to the FAT and indirection table
+
+@param aFatIndex Cluster number to write to
+@param aFatValue Cluster value for Fat
+@param anIndirectionValue Value for indirection table
+*/
+void CRamFatTable::WriteFatTable(TInt aFatIndex,TInt aFatValue,TInt anIndirectionValue)
+    {
+    TUint8* pos=RamDiskBase()+PosInBytes(aFatIndex);
+    *(TUint16*)(pos+iFatTablePos)=(TUint16)aFatValue;
+    *(TUint16*)(pos+iIndirectionTablePos)=(TUint16)anIndirectionValue;
+    }
+
+/**
+Write to just the fat table
+
+@param aFatIndex Cluster number to write to
+@param aFatValue Cluster value for Fat
+*/
+void CRamFatTable::WriteFatTable(TInt aFatIndex,TInt aFatValue)
+    {
+    *(TUint16*)(RamDiskBase()+PosInBytes(aFatIndex)+iFatTablePos)=(TUint16)aFatValue;
+    }
+
+/**
+Write to just the fat table
+
+@param aFatIndex Cluster number to write to
+@param aFatValue Value for indirection table
+*/
+void CRamFatTable::WriteIndirectionTable(TInt aFatIndex,TInt aFatValue)
+    {
+    *(TUint16*)(RamDiskBase()+PosInBytes(aFatIndex)+iIndirectionTablePos)=(TUint16)aFatValue;
+    }
+
+/**
+Find the real location of aCluster
+
+@param aCluster Cluster to read, contians cluster value upon return
+*/
+void CRamFatTable::ReadIndirectionTable(TUint32& aCluster) const
+    {
+    aCluster=*(TUint16*)(RamDiskBase()+PosInBytes(aCluster)+iIndirectionTablePos);
+    }
+
+/**
+Copy memory in RAM drive area, unlocking required
+
+@param aTrg Pointer to destination location
+@param aSrc Pointer to source location
+@param aLength Length of data to copy
+@return Pointer to end of data copied
+*/
+TUint8* CRamFatTable::MemCopy(TAny* aTrg,const TAny* aSrc,TInt aLength)
+    {
+    TUint8* p=Mem::Copy(aTrg,aSrc,aLength);
+    return(p);
+    }
+
+/**
+    Copy memory with filling the source buffer with zeroes. Target and source buffers can overlap.
+    Used on RAMDrive srinking in order to wipe data from the file that is being deleted.
+    
+    @param   aTrg       pointer to the target address
+    @param   aSrc       pointer to the destination address
+    @param   aLength    how many bytes to copy
+    @return  A pointer to a location aLength bytes beyond aTrg (i.e. the location aTrg+aLength).
+*/
+TUint8* CRamFatTable::MemCopyFillZ(TAny* aTrg, TAny* aSrc,TInt aLength)
+{
+    //-- just copy src to the trg, the memory areas can overlap.
+    TUint8* p=Mem::Copy(aTrg, aSrc, aLength);
+    
+    //-- now zero-fill the source memory area taking into account possible overlap.
+    TUint8* pSrc = static_cast<TUint8*>(aSrc);
+    TUint8* pTrg = static_cast<TUint8*>(aTrg);
+    
+    TUint8* pZFill = NULL; //-- pointer to the beginning of zerofilled area
+    TInt    zFillLen = 0;  //-- a number of bytes to zero-fill
+    
+    if(aTrg < aSrc)
+    {
+        if(pTrg+aLength < pSrc)
+        {//-- target and source areas do not overlap
+         pZFill = pSrc;
+         zFillLen = aLength;
+        }
+        else
+        {//-- target and source areas overlap, try not to corrupt the target area
+         zFillLen = pSrc-pTrg;
+         pZFill = pTrg+aLength;
+        }
+    }
+    else
+    {
+        if(pSrc+aLength < pTrg)
+        {//-- target and source areas do not overlap
+         pZFill = pSrc;
+         zFillLen = aLength;
+        }
+        else
+        {//-- target and source areas overlap, try not to corrupt the target area
+         zFillLen = pSrc+aLength-pTrg;
+         pZFill = pSrc;
+        }
+    }
+
+    Mem::FillZ(pZFill, zFillLen);
+
+    return(p);
+}
+
+/**
+    Zero fill RAM area corresponding to the cluster number aCluster
+    @param  aCluster a cluster number to be zero-filled
+*/
+void CRamFatTable::ZeroFillCluster(TInt aCluster)
+{
+        TLinAddr clusterPos= I64LOW(DataPositionInBytes(aCluster));
+        Mem::FillZ(iRamDiskBase+clusterPos, 1<< iOwner->ClusterSizeLog2());     
+    }
+
+
+/**
+Return the location of a Cluster in the data section of the media
+
+@param aCluster to find location of
+@return Byte offset of the cluster data 
+*/
+TInt64 CRamFatTable::DataPositionInBytes(TUint32 aCluster) const
+    {
+    //__PRINT(_L("CRamFatTable::DataPositionInBytes"));
+    ReadIndirectionTable(aCluster);
+    return(aCluster<<iOwner->ClusterSizeLog2());
+    }
+
+/**
+Allocate and mark as EOF a single cluster as close as possible to aNearestCluster,
+calls base class implementation but must Enlarge the RAM drive first. Allocated cluster RAM area will be zero-filled.
+
+@param  aNearestCluster Cluster the new cluster should be nearest to
+@leave  System wide error codes
+@return The cluster number allocated
+*/
+TUint32 CRamFatTable::AllocateSingleClusterL(TUint32 aNearestCluster)
+    {
+    __PRINT(_L("CRamFatTable::AllocateSingleClusterL"));
+    iOwner->EnlargeL(1<<iOwner->ClusterSizeLog2()); //  First enlarge the RAM drive
+    TInt fileAllocated=CFatTable::AllocateSingleClusterL(aNearestCluster); //   Now update the free cluster and fat/fit
+    ZeroFillCluster(fileAllocated);  //-- zero-fill allocated cluster 
+    return(fileAllocated);
+    }   
+
+
+/**
+    Extend a file or directory cluster chain, enlarging RAM drive first. Allocated clusters are zero-filled.
+    Leaves if there are no free clusters (the disk is full).
+    Note that method now doesn't call CFatTable::ExtendClusterListL() from its base class, be careful making changes there.
+
+    @param aNumber      number of clusters to allocate
+    @param aCluster     starting cluster number / ending cluster number after
+    @leave              KErrDiskFull + system wide error codes
+*/
+void CRamFatTable::ExtendClusterListL(TUint32 aNumber,TInt& aCluster)
+    {
+    __PRINT(_L("CRamFatTable::ExtendClusterListL"));
+    __ASSERT_DEBUG(aNumber>0,Fault(EFatBadParameter));
+    
+    iOwner->EnlargeL(aNumber<<iOwner->ClusterSizeLog2());
+
+    while(aNumber && GetNextClusterL(aCluster))
+        aNumber--;
+
+    if(!aNumber)
+        return;
+
+    if (NumberOfFreeClusters() < aNumber)
+        {
+        __PRINT(_L("CRamFatTable::ExtendClusterListL - leaving KErrDirFull"));
+        User::Leave(KErrDiskFull);
+        }
+
+    while (aNumber--)
+        {
+        const TInt freeCluster=FindClosestFreeClusterL(aCluster);
+
+        WriteFatEntryEofL(freeCluster); //  Must write EOF for FindClosestFreeCluster to work again
+        DecrementFreeClusterCount(1);
+        WriteL(aCluster,freeCluster);
+        aCluster=freeCluster;
+        ZeroFillCluster(freeCluster); //-- zero fill just allocated cluster (RAM area)
+        }
+
+    SetFreeClusterHint(aCluster); 
+  
+    }
+
+/**
+Mark a chain of clusters as free in the FAT. Shrinks the RAM drive once the
+clusters are free 
+
+@param aCluster Start cluster of cluster chain to free
+@leave System wide error codes
+*/
+void CRamFatTable::FreeClusterListL(TUint32 aCluster)
+    {
+    __PRINT1(_L("CRamFatTable::FreeClusterListL aCluster=%d"),aCluster);
+    if (aCluster==0)
+        return; // File has no cluster allocated
+
+    const TInt clusterShift=iOwner->ClusterSizeLog2();
+    TInt startCluster=aCluster;
+    TInt endCluster=0;
+    TInt totalFreed=0;
+    TLinAddr srcEnd=0;
+
+    while(endCluster!=EOF_16Bit)
+        {
+        TInt num=CountContiguousClustersL(startCluster,endCluster,KMaxTInt);
+        if (GetNextClusterL(endCluster)==EFalse || endCluster==0)
+            endCluster=EOF_16Bit;   // endCluster==0 -> file contained FAT loop
+
+    //  Real position in bytes of the start cluster in the data area
+        TLinAddr startClusterPos= I64LOW(DataPositionInBytes(startCluster));
+    //  Sliding value when more than one block is freed
+        TLinAddr trg=startClusterPos-(totalFreed<<clusterShift);
+        __PRINT1(_L("trg=0x%x"),trg);
+
+    //  Beginning of data area to move
+        TLinAddr srcStart=startClusterPos+(num<<clusterShift);
+        __PRINT1(_L("srcStart=0x%x"),srcStart);
+    //  Position of next part of cluster chain or position of end of ram drive
+        if (endCluster==EOF_16Bit)  //  Last cluster is the end of the chain
+            {
+        
+    
+        //  Fixed to use the genuine RAM drive size rather than the number
+        //  of free clusters - though they *should* be the same
+        //  It avoids the problem of iFreeClusters getting out of sync with 
+        //  the RAM drive size but doesn't solve the issue of why it can happen...
+            
+            srcEnd=I64LOW(iOwner->Size());
+            __PRINT1(_L("srcEnd=0x%x"),srcEnd);
+            }
+        else                        //  Just move up to the next part of the chain
+            srcEnd=I64LOW(DataPositionInBytes(endCluster));
+
+        //-- Copy (srcEnd-srcStart) bytes from iRamDiskBase+srcStart onto iRamDiskBase+trg
+        //-- zero-filling free space to avoid leaving something important there
+        ASSERT(srcEnd >= srcStart);
+        if(srcEnd-srcStart > 0)
+            { 
+            MemCopyFillZ(iRamDiskBase+trg,iRamDiskBase+srcStart,srcEnd-srcStart);
+            }    
+        else
+            {//-- we are freeing the cluster chain at the end of the RAMdrive; Nothing to copy to the drive space that has become free,
+             //-- but nevertheless zero fill this space.
+            Mem::FillZ(iRamDiskBase+trg, num<<clusterShift);
+            }    
+        
+        totalFreed+=num;
+        startCluster=endCluster;
+        UpdateIndirectionTable(srcStart>>clusterShift,srcEnd>>clusterShift,totalFreed);
+        }
+    TInt bytesFreed=totalFreed<<clusterShift;
+    
+//  First free the cluster list
+    CFatTable::FreeClusterListL(aCluster);
+//  Now reduce the size of the RAM drive
+    iOwner->ReduceSizeL(srcEnd-bytesFreed,bytesFreed);
+    }
+
+/**
+Shift any clusters between aStart and anEnd backwards by aClusterShift
+
+@param aStart Start of shift region
+@param anEnd End of shift region
+@param aClusterShift amount to shift cluster by
+*/
+void CRamFatTable::UpdateIndirectionTable(TUint32 aStart,TUint32 anEnd,TInt aClusterShift)
+    {
+    __PRINT(_L("CRamFatTable::UpdateIndirectionTable"));
+#if defined(__WINS__)
+    TUint32 count=iOwner->MaxClusterNumber();
+    while (count--)
+        {
+        TUint32 cluster=count;
+        ReadIndirectionTable(cluster);
+        if (cluster>=aStart && cluster<anEnd)
+            WriteIndirectionTable(count,cluster-aClusterShift);
+        }
+#else
+    TUint16* table=(TUint16*)(RamDiskBase()+iIndirectionTablePos);
+    TUint16* entry=table+iOwner->MaxClusterNumber();
+    while (entry>table)
+        {
+        TUint32 cluster=*--entry;
+        if (cluster<aStart)
+            continue;
+        if (cluster<anEnd)
+            *entry=TUint16(cluster-aClusterShift);
+        }
+#endif
+    }
+
+
+
+
+
+