Re: [PATCH v4 4/4] sha1_name: minimize OID comparisons during disambiguation
From: Jeff King <hidden>
Date: 2017-10-09 13:49:42
On Sun, Oct 08, 2017 at 02:49:42PM -0400, Derrick Stolee wrote:
quoted hunk ↗ jump to hunk
@@ -505,6 +506,65 @@ static int extend_abbrev_len(const struct object_id *oid, void *cb_data) return 0; } +static void find_abbrev_len_for_pack(struct packed_git *p, + struct min_abbrev_data *mad) +{ + int match = 0; + uint32_t num, last, first = 0; + struct object_id oid; + + open_pack_index(p); + num = p->num_objects; + last = num; + while (first < last) {[...]
Your cover letter lists: * Silently skip packfiles that fail to open with open_pack_index() as a change from the previous version. But this looks the same as the last round. I think this _does_ end up skipping such packfiles because p->num_objects will be zero. Is it worth having a comment to that effect (or even just an early return) to make it clear that the situation is intentional? Although...
+ /*
+ * first is now the position in the packfile where we would insert
+ * mad->hash if it does not exist (or the position of mad->hash if
+ * it does exist). Hence, we consider a maximum of three objects
+ * nearby for the abbreviation length.
+ */
+ mad->init_len = 0;
+ if (!match) {
+ nth_packed_object_oid(&oid, p, first);
+ extend_abbrev_len(&oid, mad);If we have zero objects in the pack, what would nth_packed_object_oid() be returning here? So I actually think we do want an early return, not just when open_packed_index() fails, but also when p->num_objects is zero. -Peff