Function reorderqueue_push

src/backend/executor/nodeIndexscan.c:461–490

* Helper function to push a tuple to the reorder queue. */

 * Helper function to push a tuple to the reorder queue.
 */
static void
reorderqueue_push(IndexScanState *node, TupleTableSlot *slot,
				  Datum *orderbyvals, bool *orderbynulls)
{
	IndexScanDesc scandesc = node->iss_ScanDesc;
	EState	   *estate = node->ss.ps.state;
	MemoryContext oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
	ReorderTuple *rt;
	int			i;

	rt = (ReorderTuple *) palloc(sizeof(ReorderTuple));
	rt->htup = ExecCopySlotHeapTuple(slot);
	rt->orderbyvals =
		(Datum *) palloc(sizeof(Datum) * scandesc->numberOfOrderBys);
	rt->orderbynulls =
		(bool *) palloc(sizeof(bool) * scandesc->numberOfOrderBys);
	for (i = 0; i < node->iss_NumOrderByKeys; i++)
	{
		if (!orderbynulls[i])
			rt->orderbyvals[i] = datumCopy(orderbyvals[i],
										   node->iss_OrderByTypByVals[i],
										   node->iss_OrderByTypLens[i]);
		else
			rt->orderbyvals[i] = (Datum) 0;
		rt->orderbynulls[i] = orderbynulls[i];
	}
	pairingheap_add(node->iss_ReorderQueue, &rt->ph_node);

	MemoryContextSwitchTo(oldContext);
}

/*
 * Helper function to pop the next tuple from the reorder queue.