Method WindowStream

src/jrd/recsrc/WindowedStream.cpp:459–546

Note that we can have NULL order here, in case of window function with shouldCallWinPass returning true, with partition, and without order. Example: ROW_NUMBER() OVER (PARTITION BY N).

// Note that we can have NULL order here, in case of window function with shouldCallWinPass
// returning true, with partition, and without order. Example: ROW_NUMBER() OVER (PARTITION BY N).
WindowedStream::WindowStream::WindowStream(thread_db* tdbb, CompilerScratch* csb, StreamType stream,
			const NestValueArray* group, BaseBufferedStream* next,
			SortNode* order, MapNode* windowMap,
			FrameExtent* frameExtent,
			Exclusion exclusion)
	: BaseAggWinStream(tdbb, csb, stream, group, NULL, false, next),
	  m_order(order),
	  m_windowMap(windowMap),
	  m_frameExtent(frameExtent),
	  m_arithNodes(csb->csb_pool),
	  m_aggSources(csb->csb_pool),
	  m_aggTargets(csb->csb_pool),
	  m_winPassSources(csb->csb_pool),
	  m_winPassTargets(csb->csb_pool),
	  m_exclusion(exclusion),
	  m_invariantOffsets(0)
{
	// Separate nodes that requires the winPass call.

	const NestConst<ValueExprNode>* const sourceEnd = m_windowMap->sourceList.end();

	for (const NestConst<ValueExprNode>* source = m_windowMap->sourceList.begin(),
			*target = m_windowMap->targetList.begin();
		 source != sourceEnd;
		 ++source, ++target)
	{
		const AggNode* aggNode = nodeAs<AggNode>(*source);

		if (aggNode)
		{
			unsigned capabilities = aggNode->getCapabilities();

			if (capabilities & AggNode::CAP_WANTS_AGG_CALLS)
			{
				m_aggSources.add(*source);
				m_aggTargets.add(*target);
			}

			if (capabilities & AggNode::CAP_WANTS_WIN_PASS_CALL)
			{
				m_winPassSources.add(*source);
				m_winPassTargets.add(*target);
			}
		}
	}

	m_arithNodes.resize(2);

	if (m_order)
	{
		dsc dummyDesc;

		for (unsigned i = 0; i < 2; ++i)
		{
			Frame* frame = i == 0 ?
				m_frameExtent->frame1 : m_frameExtent->frame2;

			if (m_frameExtent->unit == FrameExtent::Unit::RANGE && frame->value)