Method aggPass

src/dsql/AggNodes.cpp:381–436

}

bool AggNode::aggPass(thread_db* tdbb, Request* request) const
{
	dsc* desc = NULL;

	if (arg)
	{
		desc = EVL_expr(tdbb, request, arg);
		if (request->req_flags & req_null)
			return false;

		if (distinct)
		{
			fb_assert(asb);

			// "Put" the value to sort.
			impure_agg_sort* asbImpure = request->getImpure<impure_agg_sort>(asb->impure);
			UCHAR* data;
			asbImpure->iasb_sort->put(tdbb, reinterpret_cast<ULONG**>(&data));

			MOVE_CLEAR(data, asb->length);

			if (asb->intl)
			{
				// Convert to an international byte array.
				dsc to;
				to.dsc_dtype = dtype_text;
				to.dsc_flags = 0;
				to.dsc_sub_type = 0;
				to.dsc_scale = 0;
				to.dsc_ttype() = ttype_sort_key;
				to.dsc_length = asb->keyItems[0].getSkdLength();
				to.dsc_address = data;
				INTL_string_to_key(tdbb, INTL_TEXT_TO_INDEX(desc->getTextType()),
					desc, &to, INTL_KEY_UNIQUE);
			}

			dsc toDesc = asb->desc;
			toDesc.dsc_address = data +
				(asb->intl ? asb->keyItems[1].getSkdOffset() : 0);
			MOV_move(tdbb, desc, &toDesc);

			// dimitr:	Here we add a monotonically increasing value to the sort record.
			// 			It allows the record to look more random than it was originally.
			//			This helps the quick sort algorithm to avoid the worst-case of
			//			all equal values (see CORE-214).

			ULONG* const pDummy = reinterpret_cast<ULONG*>(data + asb->length - sizeof(ULONG));
			*pDummy = asbImpure->iasb_dummy++;

			return true;
		}
	}

	aggPass(tdbb, request, desc);
	return true;
}

void AggNode::aggFinish(thread_db* /*tdbb*/, Request* request) const