Hi Sergei!

On Wed, Dec 4, 2019 at 10:10 PM Sergei Golubchik <serg@mariadb.org> wrote:

...
> + Lex_cstring *strdup_root(MEM_ROOT &mem_root)

The way you use it, it looks like you really need a constructor, not
a strdup.

On second thought, it can't be a constructor because it can fail with allocation error.

But it's better to be from the other side:

bool Lex_cstring::strdup(MEM_ROOT *mem_root, const Lex_cstring &src)

{

// allocate and deep-copy from src to this

}

I'd really like to use such utility methods instead of C variants like thd_make_lex_string(). For plugins we can have strdup() method accepting THD * and compiled inside server (non-inline):

bool Lex_cstring::strdup(THD *thd, const Lex_cstring &src)

{

strdup(thd->mem_root, src);

}

We better go away from this C service layer of thd_*() functions between server and plugins and use class methods instead. We can't use THD directly though, because we don't want it compiled in plugins. So we compile non-inline methods in server that are used in plugin.

All the best,

Aleksey Midenkov
@midenok