Function append_node

sql/item_xmlfunc.cc:2615–2632

static bool
append_node(String *str, MY_XML_NODE *node)
{
  /*
   If "str" doesn't have space for a new node,
   it will allocate two times more space that it has had so far.
   (2*len+512) is a heuristic value,
   which gave the best performance during tests.
   The ideas behind this formula are:
   - It allows to have a very small number of reallocs:
     about 10 reallocs on a 1Mb-long XML value.
   - At the same time, it avoids excessive memory use.
  */
  if (str->reserve(sizeof(MY_XML_NODE), 2 * str->length() + 512))
    return TRUE;
  str->q_append((const char*) node, sizeof(MY_XML_NODE));
  return FALSE;
}


/*