Function evlRight

src/jrd/SysFunction.cpp:6484–6534

dsc* evlRight(thread_db* tdbb, const SysFunction*, const NestValueArray& args,
	impure_value* impure)
{
	fb_assert(args.getCount() == 2);

	Request* request = tdbb->getRequest();

	const dsc* value = EVL_expr(tdbb, request, args[0]);
	if (request->req_flags & req_null)	// return NULL if value is NULL
		return NULL;

	const dsc* len = EVL_expr(tdbb, request, args[1]);
	if (request->req_flags & req_null)	// return NULL if len is NULL
		return NULL;

	CharSet* charSet = INTL_charset_lookup(tdbb, value->getCharSet());
	SLONG start;

	if (value->isBlob())
	{
		blb* blob = blb::open(tdbb, tdbb->getRequest()->req_transaction,
			reinterpret_cast<bid*>(value->dsc_address));

		if (charSet->isMultiByte())
		{
			HalfStaticArray<UCHAR, BUFFER_LARGE> buffer;
			SLONG length = blob->BLB_get_data(tdbb, buffer.getBuffer(blob->blb_length),
				blob->blb_length, false);
			start = charSet->length(length, buffer.begin(), true);
		}
		else
			start = blob->blb_length / charSet->maxBytesPerChar();

		blob->BLB_close(tdbb);
	}
	else
	{
		MoveBuffer temp;
		UCHAR* p;
		start = MOV_make_string2(tdbb, value, value->getTextType(), &p, temp);
		start = charSet->length(start, p, true);
	}

	start -= MOV_get_long(tdbb, len, 0);
	start = MAX(0, start);

	dsc startDsc;
	startDsc.makeLong(0, &start);

	return SubstringNode::perform(tdbb, impure, value, &startDsc, len);
}


dsc* evlRound(thread_db* tdbb, const SysFunction* function, const NestValueArray& args,