diff -r 000000000000 -r bde4ae8d615e os/persistentdata/persistentstorage/store/pcstore/src/checkeduid.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/os/persistentdata/persistentstorage/store/pcstore/src/checkeduid.cpp Fri Jun 15 03:10:57 2012 +0200 @@ -0,0 +1,341 @@ +// Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies). +// All rights reserved. +// This component and the accompanying materials are made available +// under the terms of "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: +// + + +#include +#include +#include +#include +#include +#include "pcstoreconst.h" + +namespace PCStore +{ +const TUint crcTab[256] = + { + 0x0000,0x1021,0x2042,0x3063,0x4084,0x50a5,0x60c6,0x70e7,0x8108,0x9129,0xa14a, + 0xb16b,0xc18c,0xd1ad,0xe1ce,0xf1ef,0x1231,0x0210,0x3273,0x2252,0x52b5,0x4294, + 0x72f7,0x62d6,0x9339,0x8318,0xb37b,0xa35a,0xd3bd,0xc39c,0xf3ff,0xe3de,0x2462, + 0x3443,0x0420,0x1401,0x64e6,0x74c7,0x44a4,0x5485,0xa56a,0xb54b,0x8528,0x9509, + 0xe5ee,0xf5cf,0xc5ac,0xd58d,0x3653,0x2672,0x1611,0x0630,0x76d7,0x66f6,0x5695, + 0x46b4,0xb75b,0xa77a,0x9719,0x8738,0xf7df,0xe7fe,0xd79d,0xc7bc,0x48c4,0x58e5, + 0x6886,0x78a7,0x0840,0x1861,0x2802,0x3823,0xc9cc,0xd9ed,0xe98e,0xf9af,0x8948, + 0x9969,0xa90a,0xb92b,0x5af5,0x4ad4,0x7ab7,0x6a96,0x1a71,0x0a50,0x3a33,0x2a12, + 0xdbfd,0xcbdc,0xfbbf,0xeb9e,0x9b79,0x8b58,0xbb3b,0xab1a,0x6ca6,0x7c87,0x4ce4, + 0x5cc5,0x2c22,0x3c03,0x0c60,0x1c41,0xedae,0xfd8f,0xcdec,0xddcd,0xad2a,0xbd0b, + 0x8d68,0x9d49,0x7e97,0x6eb6,0x5ed5,0x4ef4,0x3e13,0x2e32,0x1e51,0x0e70,0xff9f, + 0xefbe,0xdfdd,0xcffc,0xbf1b,0xaf3a,0x9f59,0x8f78,0x9188,0x81a9,0xb1ca,0xa1eb, + 0xd10c,0xc12d,0xf14e,0xe16f,0x1080,0x00a1,0x30c2,0x20e3,0x5004,0x4025,0x7046, + 0x6067,0x83b9,0x9398,0xa3fb,0xb3da,0xc33d,0xd31c,0xe37f,0xf35e,0x02b1,0x1290, + 0x22f3,0x32d2,0x4235,0x5214,0x6277,0x7256,0xb5ea,0xa5cb,0x95a8,0x8589,0xf56e, + 0xe54f,0xd52c,0xc50d,0x34e2,0x24c3,0x14a0,0x0481,0x7466,0x6447,0x5424,0x4405, + 0xa7db,0xb7fa,0x8799,0x97b8,0xe75f,0xf77e,0xc71d,0xd73c,0x26d3,0x36f2,0x0691, + 0x16b0,0x6657,0x7676,0x4615,0x5634,0xd94c,0xc96d,0xf90e,0xe92f,0x99c8,0x89e9, + 0xb98a,0xa9ab,0x5844,0x4865,0x7806,0x6827,0x18c0,0x08e1,0x3882,0x28a3,0xcb7d, + 0xdb5c,0xeb3f,0xfb1e,0x8bf9,0x9bd8,0xabbb,0xbb9a,0x4a75,0x5a54,0x6a37,0x7a16, + 0x0af1,0x1ad0,0x2ab3,0x3a92,0xfd2e,0xed0f,0xdd6c,0xcd4d,0xbdaa,0xad8b,0x9de8, + 0x8dc9,0x7c26,0x6c07,0x5c64,0x4c45,0x3ca2,0x2c83,0x1ce0,0x0cc1,0xef1f,0xff3e, + 0xcf5d,0xdf7c,0xaf9b,0xbfba,0x8fd9,0x9ff8,0x6e17,0x7e36,0x4e55,0x5e74,0x2e93, + 0x3eb2,0x0ed1,0x1ef0 + }; + +/** +Performs a CCITT CRC checksum on the specified data. + +On return from this function, the referenced 16 bit integer contains the checksum. + +@param aCrc A reference to a 16 bit integer to contain the checksum. +@param aPtr A pointer to the start of the data to be checksum. +@param aLength The length of the data to be checksum. +*/ +void Crc(TUint16& aCrc,const void* aPtr,TInt aLength) + { + const TUint8* pB=static_cast(aPtr); + const TUint8* pE=pB+aLength; + TUint crc=aCrc; + while (pB>8)^*pB++)&0xff]; + } + aCrc=(TUint16)crc; + } + + +/** +Generate a checksum for the object of TCheckedUid. + +@param aPtr The pointer to the TCheckedUid. +@return The resulted checksum for the TCheckedUid. +*/ +TUint checkSum(const void *aPtr) + { + const TUint8* pB=static_cast(aPtr); + const TUint8* pE=pB+(KMaxCheckedUid*sizeof(TUid)); + TUint8 buf[(KMaxCheckedUid*sizeof(TUid))>>1]; + TUint8* pT=(&buf[0]); + while (pB>1); + return(crc); + } + +/** +Constructor that creates a zero-valued UID type. +*/ +TUidType::TUidType() + { + memset(this,0,sizeof(TUidType)); + } + + +/** +Constructor that creates a UID type and sets the UID1 component +to the specified value. + +The UID2 and UID3 components are set to KNullUid. + +@param aUid1 Value for UID1. +*/ +TUidType::TUidType(TUid aUid1) + { + memset(this,0,sizeof(TUidType)); + iUid[0]=aUid1; + } + + +/** +Constructor that creates a UID type and sets the UID1 and UID2 components +to the specified values. + +The UID3 component is set to KNullUid. + +@param aUid1 Value for UID1. +@param aUid2 Value for UID2. +*/ +TUidType::TUidType(TUid aUid1, TUid aUid2) + { + iUid[0]=aUid1; + iUid[1]=aUid2; + iUid[2]=KNullUid; + } + +/** +Constructor that creates a UID type and sets all three UID components +to the specified values. + +@param aUid1 Value for UID1. +@param aUid2 Value for UID2. +@param aUid3 Value for UID3. +*/ +TUidType::TUidType(TUid aUid1, TUid aUid2, TUid aUid3) + { + iUid[0]=aUid1; + iUid[1]=aUid2; + iUid[2]=aUid3; + } + + +/** +Compares this UID type for inequality with the specified UID type. + +@param aUidType The UID type to be compared. +@return TRUE, if any component UID is not equal to the corresponding component +UID in the specified UID type; FALSE otherwise. +*/ +TBool TUidType::operator !=(const TUidType& aUidType) const + { + return(!(*this==aUidType)); + } + +/** +Compares this UID type for equality with the specified UID type. + +@param aUidType The reference to the UID type to be compared. +@return TRUE, if each component UID is equal to the corresponding component +UID in the specified UID type; FALSE, otherwise. +*/ +TBool TUidType::operator ==(const TUidType& aUidType) const + { + return(iUid[0]==aUidType.iUid[0] && + iUid[1]==aUidType.iUid[1] && + iUid[2]==aUidType.iUid[2]); + } + + +/** +Gets the most derived UID. + +Taking the three UID components as a hierarchy with UID1 being the most general, +UID2 being more specific than UID1 and UID3 being more specific than UID2, +then the function returns: + +UID3, if UID3 is not KNullUid. +UID2, if UID2 is not KNullUid. +UID1, otherwise + +@return The most derived UID. +*/ +TUid TUidType::MostDerived() const + { + if (iUid[2]!=KNullUid) + { + return(iUid[2]); + } + if (iUid[1]!=KNullUid) + { + return(iUid[1]); + } + return(iUid[0]); + } + +/** +Gets the UID component as identified by the specified index. + +@param aIndex Index value indicating which UID component to return. + 0 specifies UID1, + 1 specifies UID2, + 2 specifies UID3. + +aIndex must be between 0 and 2. + +@return The reference to the required UID component. +*/ +const TUid& TUidType::operator[](TInt aIndex) const + { + assert(aIndex >= 0 && aIndex <= 2); + return(iUid[aIndex]); + } + +/** +Tests the object for a valid (non-KNullUid) UID type. + +@return TRUE, if at least one of the component UIDs is not KNullUid; FALSE, +if all component UIDs are KNullUid. +*/ +TBool TUidType::IsValid() const + { + return(MostDerived()!=KNullUid); + } + + +/** +Default constructor. + +Initialises the object to binary zeroes. +*/ +TCheckedUid::TCheckedUid() + { + memset(this,0, sizeof(TCheckedUid)); + } + + +/** +Constructor taking an existing Uid type. + +The constructor calculates a checksum. + +@param aUidType The reference to a Uid type to be packaged. +*/ +TCheckedUid::TCheckedUid(const TUidType& aUidType) + { + Set(aUidType); + } + + +/** +Constructor taking an existing TCheckedUid object encapsulated within +a descriptor. + +The checksum is recalculated and must match the checksum value passed in the +encapsulated TCheckedUid object, otherwise the content of this object is reset +to binary zeroes. + +aDes should be an 8-bit descriptor which holds the contents of a TCheckedUid object. + +@param aDes The reference to an 8-bit descriptor containing an existing TCheckedUid +object. +*/ +TCheckedUid::TCheckedUid(const CDes8& aDes) + { + Set(aDes); + } + +/** +Sets the specified Uid type to be packaged, and recalculates the checksum. + +@param aUidType The reference to a Uid type to be set. +*/ +void TCheckedUid::Set(const TUidType& aUidType) + { + iType = aUidType; + iCheck = Check(); + } + +/** +Sets an existing TCheckedUid object encapsulated within a descriptor. + +The checksum is recalculated and must match the checksum value passed in the +encapsulated TCheckedUid object, otherwise the content of this object is reset +to binary zeroes. + +aDes should be an 8-bit descriptor which holds the contents of a TCheckedUid object. + +@param aDes The reference to a descriptor containing an existing TCheckedUid object. +*/ +void TCheckedUid::Set(const CDes8& aDes) + { + assert(aDes.Length() == sizeof(TCheckedUid)); + memcpy(this,aDes.Ptr(),sizeof(TCheckedUid)); + if (iCheck!=Check()) + { + memset(this,0,sizeof(TCheckedUid)); + } + } + +/** +Gets a descriptor to represent this object's data. + +@return The descriptor for this object's data. The descriptor's length +is the same as the length of a TCheckedUid object. +*/ +CDes8 TCheckedUid::Des() const + { + return(CDes8 (reinterpret_cast(this),sizeof(TCheckedUid))); + } + +/** +Gets the Uid type contained in this object. + +@return The Uid type. +*/ +const TUidType& TCheckedUid::UidType() const + { + return(iType); + } + +/** +Calculates the checksum of the UIDs. + +@return The checksum. +*/ +TUint TCheckedUid::Check() const + { + return((checkSum((reinterpret_cast(const_cast(this)))+1)<<16)|checkSum(this)); + } +}