Method compare

src/common/TextType.cpp:247–319

SSHORT TextType::compare(ULONG len1, const UCHAR* str1, ULONG len2, const UCHAR* str2)
{
	INTL_BOOL error = false;

	if (tt->texttype_fn_compare)
		return (*tt->texttype_fn_compare)(tt, len1, str1, len2, str2, &error);

	const UCHAR* space = getCharSet()->getSpace();
	BYTE spaceLength = getCharSet()->getSpaceLength();
	Firebird::HalfStaticArray<UCHAR, BUFFER_SMALL> utf16Str1;
	Firebird::HalfStaticArray<UCHAR, BUFFER_SMALL> utf16Str2;
	UCHAR utf16Space[sizeof(ULONG)];

	if (getCharSet()->isMultiByte())
	{
		// convert str1 to UTF-16
		ULONG utf16Length = getCharSet()->getConvToUnicode().convertLength(len1);

		len1 = getCharSet()->getConvToUnicode().convert(len1, str1,
					utf16Length, utf16Str1.getBuffer(utf16Length));
		str1 = utf16Str1.begin();

		// convert str2 to UTF-16
		utf16Length = getCharSet()->getConvToUnicode().convertLength(len2);

		len2 = getCharSet()->getConvToUnicode().convert(len2, str2,
					utf16Length, utf16Str2.getBuffer(utf16Length));
		str2 = utf16Str2.begin();

		// convert charset space to UTF-16
		spaceLength =
			getCharSet()->getConvToUnicode().convert(spaceLength, space, sizeof(utf16Space), utf16Space);
		fb_assert(spaceLength == 2);	// space character can't be surrogate for default compare
		space = utf16Space;
	}

	if (tt->texttype_pad_option)
	{
		const UCHAR* pad;

		for (pad = str1 + len1 - spaceLength; pad >= str1; pad -= spaceLength)
		{
			if (memcmp(pad, space, spaceLength) != 0)
				break;
		}

		len1 = pad - str1 + spaceLength;

		for (pad = str2 + len2 - spaceLength; pad >= str2; pad -= spaceLength)
		{
			if (memcmp(pad, space, spaceLength) != 0)
				break;
		}

		len2 = pad - str2 + spaceLength;
	}

	if (getCharSet()->isMultiByte())