Function evlReplace

src/jrd/SysFunction.cpp:6223–6378

dsc* evlReplace(thread_db* tdbb, const SysFunction*, const NestValueArray& args,
	impure_value* impure)
{
	fb_assert(args.getCount() == 3);

	Request* request = tdbb->getRequest();
	dsc* values[3];	// 0 = searched, 1 = find, 2 = replacement
	const dsc* firstBlob = NULL;

	for (int i = 0; i < 3; ++i)
	{
		values[i] = EVL_expr(tdbb, request, args[i]);
		if (request->req_flags & req_null)	// return NULL if values[i] is NULL
			return NULL;

		if (!firstBlob && values[i]->isBlob())
			firstBlob = values[i];
	}

	const USHORT ttype = values[0]->getTextType();
	TextType* tt = INTL_texttype_lookup(tdbb, ttype);
	CharSet* cs = tt->getCharSet();
	const UCHAR canonicalWidth = tt->getCanonicalWidth();

	MoveBuffer buffers[3];
	UCHAR* addresses[3];
	ULONG lengths[3];

	for (int i = 0; i < 3; ++i)
	{
		if (values[i]->isBlob())
		{
			// values[i] is a blob
			blb* blob = blb::open(tdbb, tdbb->getRequest()->req_transaction,
				reinterpret_cast<bid*>(values[i]->dsc_address));

			addresses[i] = buffers[i].getBuffer(blob->blb_length);
			lengths[i] = blob->BLB_get_data(tdbb, addresses[i], blob->blb_length, true);
		}
		else
			lengths[i] = MOV_make_string2(tdbb, values[i], ttype, &addresses[i], buffers[i]);
	}

	if (lengths[1] == 0)
		return values[0];

	HalfStaticArray<UCHAR, BUFFER_SMALL> canonicals[2];	// searched, find
	for (int i = 0; i < 2; ++i)
	{
		canonicals[i].getBuffer(lengths[i] / cs->minBytesPerChar() * canonicalWidth);
		canonicals[i].resize(tt->canonical(lengths[i], addresses[i],
			canonicals[i].getCount(), canonicals[i].begin()) * canonicalWidth);
	}

	blb* newBlob = NULL;

	// make descriptor for return value
	if (!firstBlob)