Symaptic: os/kernelhwsrv/kernel/eka/debug/crashMonitor/src/scmchksum.cpp@260cb5ec6c19

     1 // Copyright (c) 2008-2009 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 // e32\debug\crashMonitor\src\scmchksum.cpp

    15 //

    16 //

    18 /**

    19  @file

    20  @internalTechnology

    21 */

    23 #include <scmdatatypes.h>

    25 namespace Debug

    26 	{

    27 	/**

    28 	 * Constructor

    29 	 */

    30 	TScmChecksum::TScmChecksum()

    31 	: iLength(0)

    32 	, iSum(0)

    33 	, iZeroCount(0)

    34 		{

    35 		}

    37 	/**

    38 	 * ChecksumBlock - calculate checksum values for given data

    39 	 * @param aData - the data to checksum

    40 	 * @param aLen - the length of the data to checksum

    41 	 * @return void

    42 	 */

    43 	void TScmChecksum::ChecksumBlock(const TUint8* aData, TUint aLen)

    44 		{

    45 		/**

    46 		 *

    47 		 * Note there is Symbian CRC implementation to be found in the following

    48 		 * \src\cedar\generic\tools\e32tools\elf2e32\source\checksum.h

    49 		 * \src\cedar\generic\tools\e32tools\elf2e32\source\checksum.cpp

    50 		 * this however may be no good to us

    51 		 * as we need to produce a single checksum even though the entire data may be

    52 		 * read in different size blocks - and the entire data may not be available

    53 		 * (the comm port requirement is for read only )

    54 		 * If we do however want to use the CRC then this is the place to insert the code

    55 		 */

    56 		if(!aData)

    57 			{

    58 			return;

    59 			}

    61 		for(TUint i=0;i<aLen;i++)

    62 			{

    63 			TUint8 val = *(aData+i);

    65 			iLength++;

    66 			if(val == 0)

    67 				{

    68 				iZeroCount++;

    69 				}

    70 			else

    71 				{

    72 				iSum += val;

    73 				}

    74 			}

    75 		}

    77 	/**

    78 	 * ChecksumBlock - calculate checksum values for given data

    79 	 * @param aData - descriptor containing the data to checksum

    80 	 * @return void

    81 	 */

    82 	void TScmChecksum::ChecksumBlock(const TDesC8& aDes)

    83 		{

    84 		ChecksumBlock(aDes.Ptr(), aDes.Length());

    85 		}

    87 	/**

    88 	 * ChecksumBlock - operator ==

    89 	 * @param aOther - the TScmChecksum to compare too

    90 	 * @return ETrue is objects match - otherwise EFalse

    91 	 */

    92 	TBool TScmChecksum::operator == (const TScmChecksum& aOther) const

    93 		{

    94 		return (iLength == aOther.iLength && iSum == aOther.iSum && iZeroCount == aOther.iZeroCount);

    95 		}

    97 	/**

    98 	 * ChecksumBlock - operator !=

    99 	 * @param aOther - the TScmChecksum to compare too

   100 	 * @return EFalse if objects match - otherwise ETrue

   101 	 */

   102 	TBool TScmChecksum::operator != (const TScmChecksum& aOther) const

   103 		{

   104 		return !(*this == aOther);

   105 		}

   107 	/**

   108 	 * GetSize

   109 	 * @return size of this object when streamed in bytes

   110 	 */

   111 	TInt TScmChecksum::GetSize() const

   112  		{

   113  		return 12;

   114  		}

   116 	/**

   117 	 * Serialize - writes this object to the supplied byte stream

   118 	 * @param aItem -  aWriter - the TByteStreamWriter that will be written to

   119 	 * @return One of the OS wide codes

   120 	 */

   121 	TInt TScmChecksum::Serialize(TByteStreamWriter& aWriter)

   122 		{

   123 		TInt startPos = aWriter.CurrentPosition();

   124 		aWriter.WriteInt(iLength);

   125 		aWriter.WriteInt(iSum);

   126 		aWriter.WriteInt(iZeroCount);

   127 		TInt sizeWritten = aWriter.CurrentPosition() - startPos;

   128 		if(sizeWritten != GetSize())

   129 			{

   130 			// error between actual size & real size in data

   131 			CLTRACE("TScmChecksum serialization size error");

   132 			return KErrCorrupt;

   133 			}

   134 		return KErrNone;

   135 		}

   138 	/**

   139 	 * Deserialize - read this objects state from the supplied byte stream

   140 	 * @param aItem -  aReader - the TByteStreamReader that will be read from

   141 	 * @return One of the OS wide codes

   142 	 */

   143 	TInt TScmChecksum::Deserialize(TByteStreamReader& aReader)

   144 		{

   145 		TInt startPos = aReader.CurrentPosition();

   146 		// do we need a version check here - will it change ?

   147 		iLength = aReader.ReadInt();

   148 		iSum = aReader.ReadInt();

   149 		iZeroCount = aReader.ReadInt();

   151 		TInt sizeRead = aReader.CurrentPosition() - startPos;

   152 		if(sizeRead != GetSize())

   153 			{

   154 			// error between actual size & real size in data

   155 			CLTRACE("TScmChecksum Deserialization size error");

   156 			return KErrCorrupt;

   157 			}

   158 		return KErrCorrupt;

   159 		}

   162 	void TScmChecksum::Reset()

   163 		{

   164 		iLength = iSum = iZeroCount = 0;

   165 		}

   166 	}

   167 //eof

author	sl
	Tue, 10 Jun 2014 14:32:02 +0200
changeset 1	260cb5ec6c19
permissions	-rw-r--r--