Method scalar

src/jrd/blb.cpp:1901–1951

void blb::scalar(thread_db*		tdbb,
				jrd_tra*		transaction,
				const bid*		blob_id,
				USHORT			count,
				const SLONG*	subscripts,
				impure_value*	value)
{
/**************************************
 *
 *      b l b : : s c a l a r
 *
 **************************************
 *
 * Functional description
 *
 **************************************/
	transaction = transaction->getOuter();

	SLONG stuff[IAD_LEN(16) / 4];

	SET_TDBB(tdbb);

	Ods::InternalArrayDesc* array_desc = (Ods::InternalArrayDesc*) stuff;
	blb* blob = get_array(tdbb, transaction, blob_id, array_desc);

	// Get someplace to put data.
	// We need DOUBLE_ALIGNed buffer, that's why some tricks
	HalfStaticArray<double, 64> temp;
	dsc desc = array_desc->iad_rpt[0].iad_desc;
	desc.dsc_address = reinterpret_cast<UCHAR*>(temp.getBuffer((desc.dsc_length / sizeof(double)) +
												(desc.dsc_length % sizeof(double) ? 1 : 0)));

	const SLONG number = SDL_compute_subscript(tdbb->tdbb_status_vector, array_desc, count, subscripts);
	if (number < 0)
	{
		blob->BLB_close(tdbb);
		ERR_punt();
	}

	const SLONG offset = number * array_desc->iad_element_length;
	blob->BLB_lseek(0, offset + (SLONG) array_desc->iad_length);
	blob->BLB_get_segment(tdbb, desc.dsc_address, desc.dsc_length);

	// If we have run out of data, then clear the data buffer.

	if (blob->blb_flags & BLB_eof) {
		memset(desc.dsc_address, 0, (int) desc.dsc_length);
	}
	EVL_make_value(tdbb, &desc, value);
	blob->BLB_close(tdbb);
}


static ArrayField* alloc_array(jrd_tra* transaction, Ods::InternalArrayDesc* proto_desc)