1 /*

     2 * Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of the License "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description:

    15 *

    16 */

    17 //

    18 // tmsmemmap.cpp

    19 //

    20 // Maps a position to mass storage address space

    21 //

    22 

    23 /** @file

    24 @internalTechnology

    25 */

    26 

    27 #include <e32def.h>

    28 #include <e32def_private.h>

    29 #include <e32err.h>

    30 #include <e32debug.h>

    31 

    32 #include "tmsmemmap.h"

    33 #include "debug.h"

    34 

    35 

    36 TMsDataMemMap::TMsDataMemMap()

    37 	{

    38 	__MSFNSLOG

    39     Reset();

    40 	}

    41 

    42 

    43 /**

    44     Checks that the block is within the limits of the media memory address space

    45     and truncates the length if block extends beyond media size.

    46 

    47    @param aPos [IN] Position of start address [OUT] Adjusted position to real

    48    address on media.

    49    @param aLength [IN] Number of bytes [OUT] Number of bytes truncated in case

    50    of block overflow.

    51 

    52    @return TInt KErrNone if block fits. KErrArgument if start position is

    53    greater than the media size. KErrEof if block extends beyond media size.

    54  */

    55 TInt TMsDataMemMap::TranslateDataPos(TInt64& aPos, TInt& aLength) const

    56     {

    57 	__MSFNSLOG

    58     // Map to the actual position on the media

    59     aPos += iDataOffset;

    60 

    61     if (aPos > iSize)

    62         {

    63         return KErrArgument;

    64         }

    65 

    66     TInt64 endPos = aPos + aLength;

    67     if (endPos > iSize)

    68         {

    69         aLength = iSize - aPos;

    70         return KErrEof;

    71         }

    72     return KErrNone;

    73     }

    74 

    75 /**

    76    Checks that the block is within the limits of the media memory address space

    77 

    78    @param aPos [IN] Position of start address [OUT] Adjusted position to real

    79    address on media.

    80    @param aLength Number of bytes.

    81 

    82    @return TInt KErrNone if block fits. KErrArgument if start position is

    83    greater than the media size. KErrEof if block extends beyond media size.

    84  */

    85 TInt TMsDataMemMap::CheckBlockInRange(TInt64& aPos, TInt aLength) const

    86     {

    87 	__MSFNSLOG

    88     // Map to the actual position on the media

    89     aPos += iDataOffset;

    90 

    91     if (aPos > iSize)

    92         {

    93         return KErrArgument;

    94         }

    95 

    96     TInt64 endPos = aPos + aLength;

    97     if (endPos > iSize)

    98         {

    99         __PXYPRINT2(_L("EOF found 0x%lx x%x"), aPos, aLength);

   100         return KErrEof;

   101         }

   102 

   103     return KErrNone;

   104     }