maria-developers team mailing list archive

[Sergei Golubchik <serg@xxxxxxxxxxx>]

Hi, Sergey!

On Mar 03, Sergey Vojtovich wrote:
> > > === modified file 'sql/mdl.cc'
> > > --- a/sql/mdl.cc	2014-02-14 12:25:41 +0000
> > > +++ b/sql/mdl.cc	2014-02-20 07:25:33 +0000
> > > @@ -760,13 +760,22 @@ void MDL_map::init()
> > >  }
> > >  
> > >  
> > > +my_hash_value_type mdl_hash_function(const CHARSET_INFO *cs,
> > > +                                     const uchar *key, size_t length)
> > > +{
> > > +  return *((my_hash_value_type*) (key - offsetof(MDL_key, m_ptr) +
> > > +                                        offsetof(MDL_key, m_hash_value))) +
> > > +                                       key[0];
> > 
> > I'd prefer to avoid pointer and offset juggling. Because you use a
> > custom hash function anyway, you can directly pass MDL_key as your
> > "key", then here you can use ((MDL_key*)key)->hash_value()
> I'd prefer to avoid it too. But there is hashcmp() function which is called
> when there are many records in a hash bucket. It does my_strnncoll() and
> MDL_key as it is now is not good for strnncoll.

But hashcmp() uses HASH::get_key() callback to get the key.
You can use it to return MDL_key::m_ptr

Regards,
Sergei