From 781d93067d3ab8b448a4c8989a6e3cac17009061 Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Fri, 3 Jul 2015 09:51:57 -0700 Subject: [PATCH] index-pack: fix allocation of sorted_by_pos array MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When c6458e60 (index-pack: kill union delta_base to save memory, 2015-04-18) attempted to reduce the memory footprint of index-pack, one of the key thing it did was to keep track of ref-deltas and ofs-deltas separately. In fix_unresolved_deltas(), however it forgot that it now wants to look only at ref deltas in one place. The code allocated an array for nr_unresolved, which is sum of number of ref- and ofs-deltas minus nr_resolved, which may be larger or smaller than the number ref-deltas. Depending on nr_resolved, this was either under or over allocating. Also, the old code before this change had to use 'i' and 'n' because some of the things we see in the (old) deltas[] array we scanned with 'i' would not make it into the sorted_by_pos[] array in the old world order, but now because you have only ref delta in a separate ref_deltas[] array, they increment lock&step. We no longer need separate variables. And most importantly, we shouldn't pass the nr_unresolved parameter, as this number does not play a role in the working of this helper function. Helped-by: Nguyễn Thái Ngọc Duy Signed-off-by: Junio C Hamano --- builtin/index-pack.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/builtin/index-pack.c b/builtin/index-pack.c index 3ed53e3c9b..fa13e20094 100644 --- a/builtin/index-pack.c +++ b/builtin/index-pack.c @@ -1223,7 +1223,7 @@ static void resolve_deltas(void) * - append objects to convert thin pack to full pack if required * - write the final 20-byte SHA-1 */ -static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved); +static void fix_unresolved_deltas(struct sha1file *f); static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1) { if (nr_ref_deltas + nr_ofs_deltas == nr_resolved_deltas) { @@ -1245,7 +1245,7 @@ static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned cha memset(objects + nr_objects + 1, 0, nr_unresolved * sizeof(*objects)); f = sha1fd(output_fd, curr_pack); - fix_unresolved_deltas(f, nr_unresolved); + fix_unresolved_deltas(f); strbuf_addf(&msg, _("completed with %d local objects"), nr_objects - nr_objects_initial); stop_progress_msg(&progress, msg.buf); @@ -1328,10 +1328,10 @@ static int delta_pos_compare(const void *_a, const void *_b) return a->obj_no - b->obj_no; } -static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved) +static void fix_unresolved_deltas(struct sha1file *f) { struct ref_delta_entry **sorted_by_pos; - int i, n = 0; + int i; /* * Since many unresolved deltas may well be themselves base objects @@ -1343,12 +1343,12 @@ static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved) * before deltas depending on them, a good heuristic is to start * resolving deltas in the same order as their position in the pack. */ - sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos)); + sorted_by_pos = xmalloc(nr_ref_deltas * sizeof(*sorted_by_pos)); for (i = 0; i < nr_ref_deltas; i++) - sorted_by_pos[n++] = &ref_deltas[i]; - qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare); + sorted_by_pos[i] = &ref_deltas[i]; + qsort(sorted_by_pos, nr_ref_deltas, sizeof(*sorted_by_pos), delta_pos_compare); - for (i = 0; i < n; i++) { + for (i = 0; i < nr_ref_deltas; i++) { struct ref_delta_entry *d = sorted_by_pos[i]; enum object_type type; struct base_data *base_obj = alloc_base_data();