Method WindowedStream

src/jrd/recsrc/WindowedStream.cpp:208–358

// ------------------------------

WindowedStream::WindowedStream(thread_db* tdbb, Optimizer* opt,
			ObjectsArray<WindowSourceNode::Window>& windows, RecordSource* next)
	: RecordSource(opt->getCompilerScratch()),
	  m_joinedStream(nullptr)
{
	const auto csb = opt->getCompilerScratch();

	m_next = FB_NEW_POOL(csb->csb_pool) BufferedStream(csb, next);
	m_impure = csb->allocImpure<Impure>();
	m_cardinality = next->getCardinality();

	// Process the unpartioned and unordered map, if existent.

	for (auto& window : windows)
	{
		// While here, verify not supported functions/clauses.

		if (window.order || window.frameExtent->unit == FrameExtent::Unit::ROWS)
		{
			for (const auto& source : window.map->sourceList)
			{
				if (const auto aggNode = nodeAs<AggNode>(source))
				{
					const char* arg = nullptr;

					if (aggNode->distinct)
						arg = "DISTINCT";
					else if (!(aggNode->getCapabilities() & AggNode::CAP_SUPPORTS_WINDOW_FRAME))
						arg = aggNode->aggInfo.name;

					if (arg)
					{
						string msg;
						msg.printf("%s is not supported in windows with ORDER BY or frame by ROWS clauses", arg);

						status_exception::raise(
							Arg::Gds(isc_wish_list) <<
							Arg::Gds(isc_random) << msg);
					}
				}
			}
		}

		if (!window.group && !window.order)
		{
			if (!m_joinedStream)
			{
				m_joinedStream = FB_NEW_POOL(csb->csb_pool) WindowStream(tdbb, csb, window.stream,
					nullptr, FB_NEW_POOL(csb->csb_pool) BufferedStreamWindow(csb, m_next),
					nullptr, window.map, window.frameExtent, window.exclusion);
			}
			else
			{
				m_joinedStream = FB_NEW_POOL(csb->csb_pool) WindowStream(tdbb, csb, window.stream,
					nullptr, FB_NEW_POOL(csb->csb_pool) BufferedStream(csb, m_joinedStream),
					nullptr, window.map, window.frameExtent, window.exclusion);
			}