Function binaryheap_replace_first

src/backend/lib/binaryheap.c:203–212

* binaryheap_replace_first * * Replace the topmost element of a non-empty heap, preserving the heap * property. O(1) in the best case, or O(log n) if it must fall back to * sifting the new node down. */

 * sifting the new node down.
 */
void
binaryheap_replace_first(binaryheap *heap, Datum d)
{
	Assert(!binaryheap_empty(heap) && heap->bh_has_heap_property);

	heap->bh_nodes[0] = d;

	if (heap->bh_size > 1)
		sift_down(heap, 0);
}

/*
 * Swap the contents of two nodes.