Like in the previous patch for compat/qsort_s.c, remove the optimization
of using an on-stack buffer to avoid small allocations. This ensures
maximum alignment for the array elements and simplifies the code a bit.
The performance impact for the current callers is unlikely to be
noticeable:
* compat/mingw.c::make_environment_block() uses ALLOC_ARRAY and
ALLOC_GROW several times already, so another allocation of up to 1KB
should not matter much.
* diffcore-rename.c::diffcore_rename_extended() is called once per diff
or twice per merge, and those require allocations for each object and
more already.
* merge-ort.c::detect_and_process_renames() is called once per merge.
It's responsible for the two per-merge diffcore_rename_extended()
calls mentioned above as well, though. So this is possibly the most
impacted caller. Per-object allocations are likely to dwarf the
additional small allocations in git_stable_qsort(), though.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `qsort()` function is not guaranteed to be stable, i.e. it does not
promise to maintain the order of items it is told to consider equal. In
contrast, the `git_sort()` function we carry in `compat/qsort.c` _is_
stable, by virtue of implementing a merge sort algorithm.
In preparation for using a stable sort in Git's rename detection, move
the stable sort into `libgit.a` so that it is compiled in
unconditionally, and rename it to `git_stable_qsort()`.
Note: this also makes the hack obsolete that was introduced in
fe21c6b285 (mingw: reencode environment variables on the fly (UTF-16
<-> UTF-8), 2018-10-30), where we included `compat/qsort.c` directly in
`compat/mingw.c` to use the stable sort.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
