Method transformString

src/dsql/Parser.cpp:131–189

Transform strings (or substrings) prefixed with introducer (_charset) to ASCII equivalent.

// Transform strings (or substrings) prefixed with introducer (_charset) to ASCII equivalent.
void Parser::transformString(const char* start, unsigned length, string& dest)
{
	const static char HEX_DIGITS[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
		'A', 'B', 'C', 'D', 'E', 'F'};

	const unsigned fromBegin = start - lex.start;
	HalfStaticArray<char, 256> buffer;
	const char* pos = start;

	// We need only the "introduced" strings, in the bounds of "start" and "length" and in "pos"
	// order. Let collect them.

	SortedArray<StrMark> introducedMarks;

	GenericMap<NonPooled<IntlString*, StrMark> >::ConstAccessor accessor(&strMarks);
	for (bool found = accessor.getFirst(); found; found = accessor.getNext())
	{
		const StrMark& mark = accessor.current()->second;
		if (mark.introduced && mark.pos >= fromBegin && mark.pos < fromBegin + length)
			introducedMarks.add(mark);
	}

	for (FB_SIZE_T i = 0; i < introducedMarks.getCount(); ++i)
	{
		const StrMark& mark = introducedMarks[i];

		const char* s = lex.start + mark.pos;
		buffer.add(pos, s - pos);

		if (!isspace(UCHAR(pos[s - pos - 1])))
			buffer.add(' ');	// fix _charset'' becoming invalid syntax _charsetX''

		const FB_SIZE_T count = buffer.getCount();
		const FB_SIZE_T newSize = count + 2 + mark.str->getString().length() * 2 + 1;
		buffer.grow(newSize);
		char* p = buffer.begin() + count;

		*p++ = 'X';
		*p++ = '\'';

		const char* s2 = mark.str->getString().c_str();

		for (const char* end = s2 + mark.str->getString().length(); s2 < end; ++s2)
		{
			*p++ = HEX_DIGITS[UCHAR(*s2) >> 4];
			*p++ = HEX_DIGITS[UCHAR(*s2) & 0xF];
		}

		*p = '\'';
		fb_assert(p < buffer.begin() + newSize);

		pos = s + mark.length;
	}

	fb_assert(start + length - pos >= 0);
	buffer.add(pos, start + length - pos);

	dest.assign(buffer.begin(), MIN(string::max_length(), buffer.getCount()));