maria-developers team mailing list archive

[Sergey Petrunia <sergey@xxxxxxxxxxx>]

On Thu, Apr 12, 2018 at 07:45:37PM +0200, Sergei Golubchik wrote:
> Hi, Sergey!
> 
> Forgot to mention it in my first reply, sorry
> 
> On Apr 12, Sergey Petrunia wrote:
> > > diff --git a/sql/item.h b/sql/item.h
> > > index 9574bdc63bf..e391e7810c4 100644
> > > --- a/sql/item.h
> > > +++ b/sql/item.h
> > > @@ -2023,6 +2023,7 @@ class Item: public Value_source,
> > >    {
> > >      marker &= ~EXTRACTION_MASK;
> > >    }
> > > +  virtual TABLE *rowid_table() const { return 0; }
> > 
> > I am concerned about this approach bloating class Item's vtable. 
> > 
> > There is (and likely will ever be) only one class with a different 
> > implementation, the check for this is made only in one place - why not
> > check Item's type() or functype(), etc?
> 
> I know, I don't like this either. But the alternative was
> 
>    if (item->type() == FUNC_ITEM &&
>        ((Item_func*)item)->functype() == ROWID_FUNC &&
>        ((Item_temptable_rowid*)item)->table == tbl)
>     ...
> 
> that is, I need to compare both item->type() and item_func->functype().
> So I thought it'd be better to add a method.
> 
> I can revert back to type()/functype() comparison, if you prefer that.
>
I would prefer that, if several checks are needed a short static/inline
function will be more readable...

BR
 Sergei
-- 
Sergei Petrunia, Software Developer
MariaDB Corporation | Skype: sergefp | Blog: http://s.petrunia.net/blog