Re: embedded list v2

Excerpts from Andres Freund's message of jue jun 28 16:03:26 -0400 2012:
>
> On Thursday, June 28, 2012 09:47:05 PM Alvaro Herrera wrote:
> > Excerpts from Andres Freund's message of jue jun 28 14:20:59 -0400 2012:
> > > Looks good now?
> >
> > The one thing I dislike about this code is the names you've chosen. I
> > mean, ilist_s_stuff and ilist_d_stuff. I mean, why not just Slist_foo
> > and Dlist_bar, say? As far as I can tell, you've chosen the "i" prefix
> > because it's "integrated" or "inline", but this seems to me a rather
> > irrelevant implementation detail that's of little use to the callers.
> Well, its not irrelevant because you actually need to change the contained
> structs to use it. I find that a pretty relevant distinction.

Sure, at that point it is relevant. Once you're past that, there's no
point. I mean, you would look up how it's used in the header comment of
the implementation, and then just refer to the API.

> > Also, I don't find so great an idea to have everything in a single file.
> > Is there anything wrong with separating singly and doubly linked lists
> > each to its own file? Other than you not liking it, I mean. As a
> > person who spends some time trying to untangle header dependencies, I
> > would appreciate keeping stuff as lean as possible. However, since
> > nobody else seems to have commented on this, maybe it's just me.
> Robert had the same comment, its not just you...
>
> It would mean duplicating the ugliness around the conditional inlining, the
> comment explaining how to use the stuff (because its basically used the same
> way for single and double linked lists), you would need to #define
> ilist_container twice or have a third file....
> Just seems to much overhead for ~100 lines (the single linked list
> implementation).

Well, then don't duplicate a comment -- create a README.lists and
refer to it in the comments. Not sure about the ilist_container stuff,
but in principle I don't have a problem with having a file with a single
#define that's included by two other headers.

> What I wonder is how hard it would be to remove catcache.h's structs into the
> implementation. Thats the reason why the old and new list implementation
> currently is included all over the backend...

Yeah, catcache.h is a pretty ugly beast. I'm sure there are ways to behead it.

--
Álvaro Herrera <alvherre(at)commandprompt(dot)com>
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