os/kernelhwsrv/userlibandfileserver/fileserver/smassstorage/massstorageutil.cpp
author sl@SLION-WIN7.fritz.box
Fri, 15 Jun 2012 03:10:57 +0200
changeset 0 bde4ae8d615e
permissions -rw-r--r--
First public contribution.
     1 // Copyright (c) 2004-2009 Nokia Corporation and/or its subsidiary(-ies).
     2 // All rights reserved.
     3 // This component and the accompanying materials are made available
     4 // under the terms of the License "Eclipse Public License v1.0"
     5 // which accompanies this distribution, and is available
     6 // at the URL "http://www.eclipse.org/legal/epl-v10.html".
     7 //
     8 // Initial Contributors:
     9 // Nokia Corporation - initial contribution.
    10 //
    11 // Contributors:
    12 //
    13 // Description:
    14 // Utility functions for the Mass Storage file system.
    15 // 
    16 //
    17 
    18 /**
    19  @file
    20  @internalTechnology
    21 */
    22 
    23 #include <e32std.h>
    24 #include <e32std_private.h>
    25 
    26 /**
    27 Returns ETrue if aNum is a power of two
    28 */
    29 GLDEF_C TBool IsPowerOfTwo(TInt aNum)
    30 	{
    31 
    32 	if (aNum==0)
    33 		return(EFalse);
    34 
    35 	while(aNum)
    36 		{
    37 		if (aNum & 0x01)
    38 			{
    39 			if (aNum>>1) 
    40 				return EFalse;
    41 			break;
    42 			}
    43 		aNum>>=1;
    44 		}
    45 	return ETrue;
    46 	}
    47 
    48 /**
    49 Returns the position of the highest bit in aNum or -1 if aNum == 0
    50 */
    51 GLDEF_C TInt Log2(TInt aNum)
    52 	{
    53 
    54 	TInt res=-1;
    55 	while(aNum)
    56 		{
    57 		res++;
    58 		aNum>>=1;
    59 		}
    60 	return(res);
    61 	}
    62