Re: [PATCH v4 4/4] sha1_name: minimize OID comparisons during disambiguation
- From
Jeff King <peff@peff.net>
- Date
- Oct 9, 2017, 13:49 UTC
- Message-ID
- <20171009134933.vmba67adelqbkx4y@sigill.intra.peff.net>
- In-Reply-To
- <20171008184942.69444-5-dstolee@microsoft.com>
On Sun, Oct 08, 2017 at 02:49:42PM -0400, Derrick Stolee wrote:
Show 16 quoted lines
> @@ -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...
Show 10 quoted lines
> + /*
> + * 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