Re: [PATCH v3 07/18] rerere: stop looping unnecessarily
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Jul 24, 2015, 20:06 UTC
- Message-ID
- <xmqq380dmiau.fsf@gitster.dls.corp.google.com>
- In-Reply-To
- <1437171880-21590-8-git-send-email-gitster@pobox.com>
Junio C Hamano <gitster@pobox.com> writes:
Show 39 quoted lines
> handle_cache() loops 3 times starting from an index entry that is
> unmerged, while ignoring an entry for a path that is different from
> what we are looking for.
>
> As the index is sorted, once we see a different path, we know we saw
> all stages for the path we are interested in. Just loop while we
> see the same path and then break, instead of continuing for 3 times.
>
> Signed-off-by: Junio C Hamano <gitster@pobox.com>
> ---
> rerere.c | 17 +++++++----------
> 1 file changed, 7 insertions(+), 10 deletions(-)
>
> diff --git a/rerere.c b/rerere.c
> index 4c45f55..7b1419c 100644
> --- a/rerere.c
> +++ b/rerere.c
> @@ -329,24 +329,21 @@ static int handle_cache(const char *path, unsigned char *sha1, const char *outpu
> return -1;
> pos = -pos - 1;
>
> - for (i = 0; i < 3; i++) {
> + while (pos < active_nr) {
> enum object_type type;
> unsigned long size;
> - int j;
>
> - if (active_nr <= pos)
> - break;
> ce = active_cache[pos++];
> if (ce_namelen(ce) != len || memcmp(ce->name, path, len))
> - continue;
> - j = ce_stage(ce) - 1;
> - mmfile[j].ptr = read_sha1_file(ce->sha1, &type, &size);
> - mmfile[j].size = size;
> + break;
> + i = ce_stage(ce) - 1;
> + mmfile[i].ptr = read_sha1_file(ce->sha1, &type, &size);
> + mmfile[i].size = size;If the conflicted index has multiple stage #1 entries, this will leak what was previously read. As the array is initialized to NULLs, perhaps
i = ce_stage(ce) - 1;
if (!mmfile[i].ptr) {
mmfile[i].ptr = read_sha1_file(ce->sha1, &type, &size);
mmfile[i].size = size;
}should be sufficient. This does change the semantics, in that we used to use the last stage #1 entry as the common ancestor when doing the plain-vanilla three-way merge, but with the leak fix, we will use the first stage #1 entry. But it does not change it in any meaningful way---we are using only one of multiple stage #1 entries arbitrarily picked either way.
Show 10 quoted lines
> }
> - for (i = 0; i < 3; i++) {
> + for (i = 0; i < 3; i++)
> if (!mmfile[i].ptr && !mmfile[i].size)
> mmfile[i].ptr = xstrdup("");
> - }
> +
> /*
> * NEEDSWORK: handle conflicts from merges with
> * merge.renormalize set, too