/*

* Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "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: 

*

*/

/**

 @file

 @internalTechnology

*/

#include "filecompare.h"

#include "cryptospi/cryptospidef.h"

#include <e32std.h>

#include <e32def.h>

#include <f32file.h>

const TInt KCompareBlockSize = 0xff;

//const TInt KCompareEqual = 0;

const TInt KCompareGreaterThan = 1;

const TInt KCompareLessThan = -1;

// a simple utility class to compare 2 files, returns

TInt TFileCompare::CompareL(TPtrC aFile1Path, TPtrC aFile2Path)

	{

	// assume is all well, compare always 

	TInt retVal = 0;

	RFs 	rFs;

	RFile	file1;

	RFile	file2;

	User::LeaveIfError(rFs.Connect());

	CleanupClosePushL(rFs);

	User::LeaveIfError(file1.Open(rFs, aFile1Path, EFileRead));

	CleanupClosePushL(file1);

	User::LeaveIfError(file2.Open(rFs, aFile2Path, EFileRead));

	CleanupClosePushL(file2);

	TInt file1Size;

	file1.Size(file1Size); 

	TInt file2Size;

	file2.Size(file2Size);

	// bail out if the sizes of the 2 files are different

	if(file1Size == file2Size)

		{

		TBuf8<KCompareBlockSize> tempBuf1;

		TBuf8<KCompareBlockSize> tempBuf2;

		TInt compareBlockSize;

		TInt loopCount;

		if(file1Size > KCompareBlockSize)

		{

			compareBlockSize = KCompareBlockSize;

			loopCount = file1Size / compareBlockSize;

		}

		else

		{

			loopCount = 1;

			compareBlockSize = file1Size;

		}

		// read through the files comparing each block

		for(TInt i = 0; i < loopCount; i++)

			{

			file1.Read(tempBuf1, compareBlockSize);

			file2.Read(tempBuf2, compareBlockSize);

			// remember, 0 is return value for a successful comparison

			retVal = tempBuf1.Compare(tempBuf2);

			if( retVal != 0 )

				{

				//if files fail to match, break out of the loop

				break;

				}		

			}

		}

	else

		{

		if(file1Size > file2Size)

			retVal = KCompareGreaterThan;

		else

			retVal = KCompareLessThan;

		}

	CleanupStack::PopAndDestroy(&file2);

	CleanupStack::PopAndDestroy(&file1);

	CleanupStack::PopAndDestroy(&rFs);

	return retVal;		

	}