1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/os/kernelhwsrv/kernel/eka/debug/crashMonitor/src/scmchksum.cpp Fri Jun 15 03:10:57 2012 +0200
1.3 @@ -0,0 +1,168 @@
1.4 +// Copyright (c) 2008-2009 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 +// e32\debug\crashMonitor\src\scmchksum.cpp
1.18 +//
1.19 +//
1.20 +
1.21 +/**
1.22 + @file
1.23 + @internalTechnology
1.24 +*/
1.25 +
1.26 +#include <scmdatatypes.h>
1.27 +
1.28 +namespace Debug
1.29 + {
1.30 + /**
1.31 + * Constructor
1.32 + */
1.33 + TScmChecksum::TScmChecksum()
1.34 + : iLength(0)
1.35 + , iSum(0)
1.36 + , iZeroCount(0)
1.37 + {
1.38 + }
1.39 +
1.40 + /**
1.41 + * ChecksumBlock - calculate checksum values for given data
1.42 + * @param aData - the data to checksum
1.43 + * @param aLen - the length of the data to checksum
1.44 + * @return void
1.45 + */
1.46 + void TScmChecksum::ChecksumBlock(const TUint8* aData, TUint aLen)
1.47 + {
1.48 + /**
1.49 + *
1.50 + * Note there is Symbian CRC implementation to be found in the following
1.51 + * \src\cedar\generic\tools\e32tools\elf2e32\source\checksum.h
1.52 + * \src\cedar\generic\tools\e32tools\elf2e32\source\checksum.cpp
1.53 + * this however may be no good to us
1.54 + * as we need to produce a single checksum even though the entire data may be
1.55 + * read in different size blocks - and the entire data may not be available
1.56 + * (the comm port requirement is for read only )
1.57 + * If we do however want to use the CRC then this is the place to insert the code
1.58 + */
1.59 + if(!aData)
1.60 + {
1.61 + return;
1.62 + }
1.63 +
1.64 + for(TUint i=0;i<aLen;i++)
1.65 + {
1.66 + TUint8 val = *(aData+i);
1.67 +
1.68 + iLength++;
1.69 + if(val == 0)
1.70 + {
1.71 + iZeroCount++;
1.72 + }
1.73 + else
1.74 + {
1.75 + iSum += val;
1.76 + }
1.77 + }
1.78 + }
1.79 +
1.80 + /**
1.81 + * ChecksumBlock - calculate checksum values for given data
1.82 + * @param aData - descriptor containing the data to checksum
1.83 + * @return void
1.84 + */
1.85 + void TScmChecksum::ChecksumBlock(const TDesC8& aDes)
1.86 + {
1.87 + ChecksumBlock(aDes.Ptr(), aDes.Length());
1.88 + }
1.89 +
1.90 + /**
1.91 + * ChecksumBlock - operator ==
1.92 + * @param aOther - the TScmChecksum to compare too
1.93 + * @return ETrue is objects match - otherwise EFalse
1.94 + */
1.95 + TBool TScmChecksum::operator == (const TScmChecksum& aOther) const
1.96 + {
1.97 + return (iLength == aOther.iLength && iSum == aOther.iSum && iZeroCount == aOther.iZeroCount);
1.98 + }
1.99 +
1.100 + /**
1.101 + * ChecksumBlock - operator !=
1.102 + * @param aOther - the TScmChecksum to compare too
1.103 + * @return EFalse if objects match - otherwise ETrue
1.104 + */
1.105 + TBool TScmChecksum::operator != (const TScmChecksum& aOther) const
1.106 + {
1.107 + return !(*this == aOther);
1.108 + }
1.109 +
1.110 + /**
1.111 + * GetSize
1.112 + * @return size of this object when streamed in bytes
1.113 + */
1.114 + TInt TScmChecksum::GetSize() const
1.115 + {
1.116 + return 12;
1.117 + }
1.118 +
1.119 + /**
1.120 + * Serialize - writes this object to the supplied byte stream
1.121 + * @param aItem - aWriter - the TByteStreamWriter that will be written to
1.122 + * @return One of the OS wide codes
1.123 + */
1.124 + TInt TScmChecksum::Serialize(TByteStreamWriter& aWriter)
1.125 + {
1.126 + TInt startPos = aWriter.CurrentPosition();
1.127 + aWriter.WriteInt(iLength);
1.128 + aWriter.WriteInt(iSum);
1.129 + aWriter.WriteInt(iZeroCount);
1.130 + TInt sizeWritten = aWriter.CurrentPosition() - startPos;
1.131 + if(sizeWritten != GetSize())
1.132 + {
1.133 + // error between actual size & real size in data
1.134 + CLTRACE("TScmChecksum serialization size error");
1.135 + return KErrCorrupt;
1.136 + }
1.137 + return KErrNone;
1.138 + }
1.139 +
1.140 +
1.141 + /**
1.142 + * Deserialize - read this objects state from the supplied byte stream
1.143 + * @param aItem - aReader - the TByteStreamReader that will be read from
1.144 + * @return One of the OS wide codes
1.145 + */
1.146 + TInt TScmChecksum::Deserialize(TByteStreamReader& aReader)
1.147 + {
1.148 + TInt startPos = aReader.CurrentPosition();
1.149 + // do we need a version check here - will it change ?
1.150 + iLength = aReader.ReadInt();
1.151 + iSum = aReader.ReadInt();
1.152 + iZeroCount = aReader.ReadInt();
1.153 +
1.154 + TInt sizeRead = aReader.CurrentPosition() - startPos;
1.155 + if(sizeRead != GetSize())
1.156 + {
1.157 + // error between actual size & real size in data
1.158 + CLTRACE("TScmChecksum Deserialization size error");
1.159 + return KErrCorrupt;
1.160 + }
1.161 + return KErrCorrupt;
1.162 + }
1.163 +
1.164 +
1.165 + void TScmChecksum::Reset()
1.166 + {
1.167 + iLength = iSum = iZeroCount = 0;
1.168 + }
1.169 + }
1.170 +//eof
1.171 +