On Wed, Jun 15, 2022 at 10:18 AM Taylor Blau <me@xxxxxxxxxxxx> wrote:
>
> [+cc Stolee]
>
> On Tue, Jun 14, 2022 at 03:25:13PM +0800, Haiyng Tan wrote:
> > I think it's caused by using lazy-fetch in
> > deref_without_lazy_fetch_extended(). In lookup_commit_in_graph(),
> > lazy-fetch is initiated by repo_has_object_file() used. has_object()
> > should be used, it's no-lazy-fetch.
>
> Hmm. Are there cases where lookup_commit_in_graph() is expected to
> lazily fetch missing objects from promisor remotes? If so, then this
> wouldn't quite work. If not, then this seems like an appropriate fix to
> me.
>
> Thanks,
> Taylor
We can see the use of has_object() in RelNotes/2.29.0.txt[1]：
* A new helper function has_object() has been introduced to make it
easier to mark object existence checks that do and don't want to
trigger lazy fetches, and a few such checks are converted using it.
Let's see the difference between has_object() and repo_has_object_file():
int has_object(struct repository *r, const struct object_id *oid,
unsigned flags)
{
int quick = !(flags & HAS_OBJECT_RECHECK_PACKED);
unsigned object_info_flags = OBJECT_INFO_SKIP_FETCH_OBJECT |
(quick ? OBJECT_INFO_QUICK : 0);
if (!startup_info->have_repository)
return 0;
return oid_object_info_extended(r, oid, NULL, object_info_flags) >= 0;
}
int repo_has_object_file_with_flags(struct repository *r,
const struct object_id *oid, int flags)
{
if (!startup_info->have_repository)
return 0;
return oid_object_info_extended(r, oid, NULL, flags) >= 0;
}
int repo_has_object_file(struct repository *r,
const struct object_id *oid)
{
return repo_has_object_file_with_flags(r, oid, 0);
}
Now we kown that has_object() add OBJECT_INFO_SKIP_FETCH_OBJECT to skip
fetch object.
I found that Ævar Arnfjörð Bjarmason added deref_without_lazy_fetch()
4 weeks ago[2]:
static struct commit *deref_without_lazy_fetch(const struct object_id *oid,
int mark_tags_complete)
{
enum object_type type;
unsigned flags = OBJECT_INFO_SKIP_FETCH_OBJECT | OBJECT_INFO_QUICK;
return deref_without_lazy_fetch_extended(oid, mark_tags_complete,
&type, flags);
}
But oi_flags is only used by oid_object_info_extended() and is missed by
lookup_commit_in_graph():
static struct commit *deref_without_lazy_fetch_extended(const struct object_id *oid,
int mark_tags_complete,
enum object_type *type,
unsigned int oi_flags)
{
struct object_info info = { .typep = type };
struct commit *commit;
commit = lookup_commit_in_graph(the_repository, oid);
if (commit)
return commit;
while (1) {
if (oid_object_info_extended(the_repository, oid, &info,
oi_flags))
So, an appropriate fix can be that let lookup_commit_in_graph() pickup
oi_flags and pass it to oid_object_info_extended(), then the fetching
loop will be prevent by the given flag OBJECT_INFO_SKIP_FETCH_OBJECT.
1. https://github.com/git/git/blob/master/Documentation/RelNotes/2.29.0.txt
2. https://lore.kernel.org/git/2a563b5f18cc9c42cb71a9547344a5435f6bc058.1652731865.git.gitgitgadget@xxxxxxxxx/
Thanks
-Han Xin
Han Xin (2):
commit-graph.c: add "flags" to lookup_commit_in_graph()
fetch-pack.c: pass "oi_flags" to lookup_commit_in_graph()
builtin/fetch.c | 4 ++-
commit-graph.c | 5 ++--
commit-graph.h | 3 +-
fetch-pack.c | 10 +++----
revision.c | 2 +-
t/t5583-fetch-with-commit-graph.sh | 47 ++++++++++++++++++++++++++++++
upload-pack.c | 5 ++--
7 files changed, 64 insertions(+), 12 deletions(-)
create mode 100644 t/t5583-fetch-with-commit-graph.sh
--
2.36.1
