[PATCH] mktree: do not check type of remote objects
- From
- Richard Oliver <roliver@roku.com>
- Date
- Jun 21, 2022, 13:59 UTC
- Message-ID
- <748f39a9-65aa-2110-cf92-7ddf81b5f507@roku.com>
- In-Reply-To
- <xmqqy1xwtsds.fsf@gitster.g>
On 16/06/2022 18:44, Junio C Hamano wrote:
Show 31 quoted lines
> This patch would be a good first cut as a starting point, but we > probably can do better by doing oid_object_info_extended() call with > OBJECT_INFO_SKIP_FETCH_OBJECT bit (and probably QUICK bit, too) set, > with the current code structure. > > And when we do so, the title would not match the purpose of the > change. The verification was disabled with "--missing" all along > and that is not what we are changing. What we will be fixing is the > wasteful implementation. > > mktree: do not check types of remote objects > > With 31c8221a (mktree: validate entry type in input, 2009-05-14), we > called the sha1_object_info() API to obtain the type information, > but allowed the call to silently fail when the object was missing > locally, so that we can sanity-check the types opportunistically > when the object did exist. > > The implementation is understandable because back then there was no > lazy/on-demand downloading of individual objects from the promisor > remotes that causes a long delay and materializes the object, hence > defeating the point of using "--missing". The design is hurting us > now. > > We could bypass the opportunistic type/mode consistency check > altogether when "--missing" is given, but instead, use the > oid_object_info_extended() API and tell it that we are only > interested in objects that locally exist and are immediately > available by passing OBJECT_INFO_SKIP_FETCH_OBJECT bit to it. That > way, we will still retain the cheap and opportunistic sanity check > for local objects.
I've prepared a patch below as per your suggestion.
As a side note, do you think we need to re-work some uses of the word 'missing' in the documentation? Some uses of the word, such as in mktree, predate the concept of promisor remotes. The partial-clone.txt documentation differentiates between missing "due to a partial clone or fetch" and missing "due to repository corruption". Would making such a distinction elsewhere be useful?
Cheers, Richard
-- >8 -- Subject: [PATCH] mktree: do not check type of remote objects
With 31c8221a (mktree: validate entry type in input, 2009-05-14), we called the sha1_object_info() API to obtain the type information, but allowed the call to silently fail when the object was missing locally, so that we can sanity-check the types opportunistically when the object did exist.
The implementation is understandable because back then there was no lazy/on-demand downloading of individual objects from the promisor remotes that causes a long delay and materializes the object, hence defeating the point of using "--missing". The design is hurting us now.
We could bypass the opportunistic type/mode consistency check altogether when "--missing" is given, but instead, use the oid_object_info_extended() API and tell it that we are only interested in objects that locally exist and are immediately available by passing OBJECT_INFO_SKIP_FETCH_OBJECT bit to it. That way, we will still retain the cheap and opportunistic sanity check for local objects.
Signed-off-by: Richard Oliver <roliver@roku.com> --- builtin/mktree.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/builtin/mktree.c b/builtin/mktree.c index 902edba6d2..cfadb52670 100644 --- a/builtin/mktree.c +++ b/builtin/mktree.c @@ -116,8 +116,15 @@ static void mktree_line(char *buf, int nul_term_line, int allow_missing) path, ptr, type_name(mode_type)); } - /* Check the type of object identified by sha1 */ - obj_type = oid_object_info(the_repository, &oid, NULL); + /* Check the type of object identified by oid without fetching objects */ + struct object_info oi = OBJECT_INFO_INIT; + oi.typep = &obj_type; + if (oid_object_info_extended(the_repository, &oid, &oi, + OBJECT_INFO_LOOKUP_REPLACE | + OBJECT_INFO_QUICK | + OBJECT_INFO_SKIP_FETCH_OBJECT) < 0) + obj_type = -1; + if (obj_type < 0) { if (allow_missing) { ; /* no problem - missing objects are presumed to be of the right type */
-- 2.36.1.467.g4f6db706e6.dirty