Re: [Emacs-diffs] /srv/bzr/emacs/trunk r109131: Return more descriptive data from Fgarbage_collect.

[Dmitry Antipov]

On 07/18/2012 10:33 AM, Stefan Monnier wrote:

> That's not regular enough.  Every entry in the list should have the
> same shape (NAME SIZE USED FREE).  For buffers, (buffers SIZE USED) is OK
> because that's like having FREE set to nil, but for strings (STRING
> INTERNAL-SIZE USED-STRINGS USED-STRING-BYTES FREE-STRING) is not good,
> we want instead to have 2 entries:
>
>    (strings SIZE USED FREE)
> and
>    (string-bytes 1 USED FREE)

IIUC, FREE is always between 0 and SBLOCK_BYTES after compacting sblocks,
so I don't see too much sense here.

> same for vectors, where we need one entry for vectors and another for
> vector slots (and BTW, please keep it vector slots rather than vector
> bytes: the SIZE part is there specifically so that code that requires
> byte counts can do the conversion later).

IMHO counting vector slots is poor idea because:
 1) vectors are of different length, so, having just a number of vector
    slots, we don't know how much of struct vectorlike_header we have
    (and they eats memory too);
 2) this doesn't count extra space beyond Lisp_Objects in pseudovectors
    and doesn't count space used by bool vectors.

Dmitry