[vlc-devel] [PATCH] opengl: vlc_list_reverse_foreach

[Hugo Beauzée-Luyssen]

On Thu, Sep 19, 2019, at 4:34 PM, Thomas Guillem wrote:
> Hello,
> 
> The commit title doesn't correspond to the patch.
> I guess it should be "list: add vlc_list_reverse_foreach"
> 
> Best,
> Thomas
> 
> On Thu, Sep 19, 2019, at 16:29, Maxime ... wrote:
> > ---
> >  include/vlc_list.h | 38 ++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 38 insertions(+)
> > 
> > diff --git a/include/vlc_list.h b/include/vlc_list.h
> > index 45263cc789..ea40b8544d 100644
> > --- a/include/vlc_list.h
> > +++ b/include/vlc_list.h
> > @@ -216,6 +216,14 @@ struct vlc_list_it vlc_list_it_start(const struct 
> > vlc_list *head)
> >      return (struct vlc_list_it){ head, first, first->next };
> >  }
> >  
> > +static inline
> > +struct vlc_list_it vlc_list_it_reverse_start(const struct vlc_list 
> > *head)
> > +{
> > +    struct vlc_list *first = head->prev;
> > +
> > +    return (struct vlc_list_it){ head, first, first->prev };
> > +}
> > +
> >  static inline bool vlc_list_it_continue(const struct vlc_list_it 
> > *restrict it)
> >  {
> >      return it->current != it->head;
> > @@ -229,6 +237,14 @@ static inline void vlc_list_it_next(struct 
> > vlc_list_it *restrict it)
> >      it->next = next->next;
> >  }
> >  
> > +static inline void vlc_list_it_prev(struct vlc_list_it *restrict it)
> > +{
> > +    struct vlc_list *next = it->next;
> > +
> > +    it->current = next;
> > +    it->next = next->prev;
> > +}
> > +
> >  #define vlc_list_entry_aligned_size(p) \
> >      ((sizeof (*(p)) + sizeof (max_align_t) - 1) / sizeof (max_align_t))
> >  
> > @@ -263,6 +279,28 @@ static inline void vlc_list_it_next(struct 
> > vlc_list_it *restrict it)
> >                                         pos, member), true); \
> >           vlc_list_it_next(&(vlc_list_it_##pos)))
> >  
> > +/**
> > + * List iteration macro.
> > + *
> > + * This macro iterates over all elements (excluding the head) of a 
> > list,
> > + * in reversed order from the first to the last.
> > + *
> > + * For each iteration, it sets the cursor variable to the current 
> > element.
> > + *
> > + * \param pos Cursor pointer variable identifier.
> > + * \param head Head pointer of the list to iterate [IN].
> > + * \param member Identifier of the member of the data type
> > + *               serving as list node.
> > + * \note It it safe to delete the current item while iterating.
> > + * It is however <b>not</b> safe to delete another item.
> > + */
> > +#define vlc_list_reverse_foreach(pos, head, member) \
> > +    for (struct vlc_list_it vlc_list_it_##pos = 
> > vlc_list_it_reverse_start(head); \
> > +         vlc_list_it_continue(&(vlc_list_it_##pos)) \
> > +          && ((pos) = vlc_list_entry_p((vlc_list_it_##pos).current, \
> > +                                       pos, member), true); \
> > +         vlc_list_it_prev(&(vlc_list_it_##pos)))
> > +
> >  /**
> >   * Converts a list node pointer to an element pointer.
> >   *

Hi,

This probably deserves a test as well :)

Regards, 

-- 
  Hugo Beauzée-Luyssen
  hugo at beauzee.fr