On 18/02/17 00:06, brian m. carlson wrote:
> There are places in the code where we would like to provide a struct
> object_id *, yet read the hash directly from the pack. Provide an
> nth_packed_object_oid function that is similar to the
> nth_packed_object_sha1 function.
>
> In order to avoid a potentially invalid cast, nth_packed_object_oid
> provides a variable into which to store the value, which it returns on
> success; on error, it returns NULL, as nth_packed_object_sha1 does.
>
> Signed-off-by: brian m. carlson <sandals@xxxxxxxxxxxxxxxxxxxx>
> ---
> cache.h | 6 ++++++
> sha1_file.c | 17 ++++++++++++++---
> 2 files changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/cache.h b/cache.h
> index e03a672d15..4f3bfc5ee7 100644
> --- a/cache.h
> +++ b/cache.h
> @@ -1608,6 +1608,12 @@ extern void check_pack_index_ptr(const struct packed_git *p, const void *ptr);
> * error.
> */
> extern const unsigned char *nth_packed_object_sha1(struct packed_git *, uint32_t n);
> +/*
> + * Like nth_packed_object_oid, but write the data into the object specified by
^^^
... Like nth_packed_object_sha1, but ...
Having said that, if the intent is to eventually replace that function with
the new nth_packed_object_oid(), then it is probably not a good idea to
describe this function in terms of the function it will obsolete. ;-)
ATB,
Ramsay Jones
> + * the the first argument. Returns the first argument on success, and NULL on
> + * error.
> + */
> +extern const struct object_id *nth_packed_object_oid(struct object_id *, struct packed_git *, uint32_t n);
>
> /*
> * Return the offset of the nth object within the specified packfile.
> diff --git a/sha1_file.c b/sha1_file.c
> index ec957db5e1..777b8e8eae 100644
> --- a/sha1_file.c
> +++ b/sha1_file.c
> @@ -2628,6 +2628,17 @@ const unsigned char *nth_packed_object_sha1(struct packed_git *p,
> }
> }
>
> +const struct object_id *nth_packed_object_oid(struct object_id *oid,
> + struct packed_git *p,
> + uint32_t n)
> +{
> + const unsigned char *hash = nth_packed_object_sha1(p, n);
> + if (!hash)
> + return NULL;
> + hashcpy(oid->hash, hash);
> + return oid;
> +}
> +
> void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
> {
> const unsigned char *ptr = vptr;
> @@ -3788,13 +3799,13 @@ static int for_each_object_in_pack(struct packed_git *p, each_packed_object_fn c
> int r = 0;
>
> for (i = 0; i < p->num_objects; i++) {
> - const unsigned char *sha1 = nth_packed_object_sha1(p, i);
> + struct object_id oid;
>
> - if (!sha1)
> + if (!nth_packed_object_oid(&oid, p, i))
> return error("unable to get sha1 of object %u in %s",
> i, p->pack_name);
>
> - r = cb(sha1, p, i, data);
> + r = cb(oid.hash, p, i, data);
> if (r)
> break;
> }
>