Am 08.02.2017 um 07:22 schrieb Duy Nguyen:
On Wed, Feb 8, 2017 at 5:04 AM, René Scharfe <l....@web.de> wrote:
Pass the match member of the first pathspec item directly to
read_directory() instead of using common_prefix() to duplicate it first,
thus avoiding memory duplication, strlen(3) and free(3).
How about killing common_prefix()? There are two other callers in
ls-files.c and commit.c and it looks safe to do (but I didn't look
very hard).
I would like that, but it doesn't look like it's worth it. I have a
patch series for making overlay_tree_on_cache() take pointer+length, but
it's surprisingly long and bloats the code. Duplicating a small piece
of memory once per command doesn't look so bad in comparison.
(The payoff for avoiding an allocation is higher for library functions
like fill_directory().)
But while working on that I found two opportunities for improvement in
prune_cache(). I'll send patches shortly.
There's a subtle difference. Before the patch, prefix[prefix_len] is
NUL. After the patch, it's not always true. If some code (incorrectly)
depends on that, this patch exposes it. I had a look inside
read_directory() though and it looks like no such code exists. So, all
good.
Thanks for checking.
NB: The code before 966de302 (dir: convert fill_directory to use the
pathspec struct interface, committed 2017-01-04) made the same
assumption, i.e. that NUL is not needed.
René
