/*

 * Copyright (c) 1997-2009 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: 

 * Little-Endian converter

 *

 */

 #include <e32std.h>

 #include <convdata.h>

 #include "unicode.h"

 #define ARRAY_LENGTH(aArray) (sizeof(aArray)/sizeof((aArray)[0]))

 GLREF_D const SCnvConversionData unicodeConversionDataLittle=

 	{

 	SCnvConversionData::EFixedLittleEndian,

 		{

 		ARRAY_LENGTH(unicodeVariableByteDataRanges),

 		unicodeVariableByteDataRanges

 		},

 		{

 		ARRAY_LENGTH(unicodeTounicodeDataRanges),

 		unicodeTounicodeDataRanges

 		},

 		{

 		ARRAY_LENGTH(unicodeTounicodeDataRanges),

 		unicodeTounicodeDataRanges

 		},

 	NULL,

 	NULL

 	};

 GLREF_C void IsCharacterSetUnicodeLittle(TInt& aConfidenceLevel, const TDesC8& aSample)

 	{

 	TInt sampleLength = aSample.Length();

 	aConfidenceLevel =70;

 	if (sampleLength < 2)

 		return;

 	if (aSample[0]==0xff)

 		{

 		// The first byte is a possible ByteOrderMark

 		// Try matching the next character 

 		if(aSample[1]==0xfe)

 			{

 			// the byte order mark could be 0xFEFF or 0xFFFE depending on 

 			// endianness of the sample text.

 			aConfidenceLevel=100;

 			}

 		}

 	for (TInt i = 0; i < sampleLength-1; ++i)

 		{

 		if (aSample[i] == 0x0d)

  			{

  			if (aSample[i+1] == 0x0a)

  				{

  				// reduce the confidence level

  				aConfidenceLevel -= 25;

  				}

  			}

 		}

 	// if not 100% confident already, check if most odd bytes zero 

 	#define MAX_SAMPLE_LENGTH 2048

 	if ( aConfidenceLevel < 100 )

 		{	

 		TInt repeat=0;

 		// only check the first MAX_SAMPLE_LENGTH if big sample

 		TInt length =( sampleLength > MAX_SAMPLE_LENGTH ? MAX_SAMPLE_LENGTH : sampleLength);

 		// start from 1 and check the odd bytes

 		for (TInt i = 1; i < length-1; i+=2)

 			{

 			if (aSample[i] == 0x0) 

 				repeat ++;

 			}

 		// if more than 80% odd bytes zero, then this IS little Endian

 		if ( (repeat * 100) /  (length * 5) >= 8)

 			aConfidenceLevel  = 100;

 		}

 	aConfidenceLevel =(aConfidenceLevel >0)? ((aConfidenceLevel > 100)? 100: aConfidenceLevel): 0;

 	}