Function _downheap

mysys/queues.c:272–318

#ifndef OLD_VERSION

void _downheap(register QUEUE *queue, uint idx)
{
  uchar *element;
  uint elements,half_queue,offset_to_key, next_index;
  my_bool first= TRUE;
  uint start_idx= idx;

  offset_to_key=queue->offset_to_key;
  element=queue->root[idx];
  half_queue=(elements=queue->elements) >> 1;

  while (idx <= half_queue)
  {
    next_index=idx+idx;
    if (next_index < elements &&
	(queue->compare(queue->first_cmp_arg,
			queue->root[next_index]+offset_to_key,
			queue->root[next_index+1]+offset_to_key) *
	 queue->max_at_top) > 0)
      next_index++;
    if (first && 
        (((queue->compare(queue->first_cmp_arg,
                          queue->root[next_index]+offset_to_key,
                          element+offset_to_key) * queue->max_at_top) >= 0)))
    {
      queue->root[idx]= element;
      return;
    }
    queue->root[idx]=queue->root[next_index];
    idx=next_index;
    first= FALSE;
  }

  next_index= idx >> 1;
  while (next_index > start_idx)
  {
    if ((queue->compare(queue->first_cmp_arg,
                       queue->root[next_index]+offset_to_key,
                       element+offset_to_key) *
         queue->max_at_top) < 0)
      break;
    queue->root[idx]=queue->root[next_index];
    idx=next_index;
    next_index= idx >> 1;
  }
  queue->root[idx]=element;
}

#else
  /*