Re: [PATCH v3 2/3] shallow: offer to prune only non-existing entries
- From
Johannes Schindelin <johannes.schindelin@gmx.de>
- Date
- Oct 24, 2018, 08:01 UTC
- Message-ID
- <nycvar.QRO.7.76.6.1810240941230.4546@tvgsbejvaqbjf.bet>
- In-Reply-To
- <xmqqmur4ovjt.fsf@gitster-ct.c.googlers.com>
Hi Junio & Jonathan,
On Wed, 24 Oct 2018, Junio C Hamano wrote:
Show 6 quoted lines
> Jonathan, do you see any issues with the use of lookup_commit() in > this change wrt lazy clone? I am wondering what happens when the > commit in question is at, an immediate parent of, or an immediate > child of a promisor object. I _think_ this change won't make it > worse for two features in playing together, but thought that it > would be better to double check.
Good point.
Instinctively, I would say that no promised object can be a shallow commit. The entire idea of a shallow commit is that it *is* present, but none of its parents.
Also, I would claim that the shallow feature does not make sense with lazy clones, as lazy clones offer a superset of shallow clone's functionality.
However, I am curious whether there is a better way to check for the presence of a local commit? Do we have an API function for that, that I missed? (I do not really want to parse the commit, after all, just verify that it is not pruned.)
Thanks, Dscho
Show 111 quoted lines
>
> "Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>
> writes:
>
> > From: Johannes Schindelin <johannes.schindelin@gmx.de>
> >
> > The `prune_shallow()` function wants a full reachability check to be
> > completed before it goes to work, to ensure that all unreachable entries
> > are removed from the shallow file.
> >
> > However, in the upcoming patch we do not even want to go that far. We
> > really only need to remove entries corresponding to pruned commits, i.e.
> > to commits that no longer exist.
> >
> > Let's support that use case.
> >
> > Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> > ---
> > builtin/prune.c | 2 +-
> > commit.h | 2 +-
> > shallow.c | 22 +++++++++++++++++-----
> > 3 files changed, 19 insertions(+), 7 deletions(-)
> >
> > diff --git a/builtin/prune.c b/builtin/prune.c
> > index 41230f821..6d6ab6cf1 100644
> > --- a/builtin/prune.c
> > +++ b/builtin/prune.c
> > @@ -161,7 +161,7 @@ int cmd_prune(int argc, const char **argv, const char *prefix)
> > free(s);
> >
> > if (is_repository_shallow(the_repository))
> > - prune_shallow(show_only);
> > + prune_shallow(show_only, 0);
> >
> > return 0;
> > }
> > diff --git a/commit.h b/commit.h
> > index 1d260d62f..ff34447ab 100644
> > --- a/commit.h
> > +++ b/commit.h
> > @@ -249,7 +249,7 @@ extern void assign_shallow_commits_to_refs(struct shallow_info *info,
> > uint32_t **used,
> > int *ref_status);
> > extern int delayed_reachability_test(struct shallow_info *si, int c);
> > -extern void prune_shallow(int show_only);
> > +extern void prune_shallow(int show_only, int quick_prune);
> > extern struct trace_key trace_shallow;
> >
> > extern int interactive_add(int argc, const char **argv, const char *prefix, int patch);
> > diff --git a/shallow.c b/shallow.c
> > index 732e18d54..0a2671bc2 100644
> > --- a/shallow.c
> > +++ b/shallow.c
> > @@ -247,6 +247,7 @@ static void check_shallow_file_for_update(struct repository *r)
> >
> > #define SEEN_ONLY 1
> > #define VERBOSE 2
> > +#define QUICK_PRUNE 4
> >
> > struct write_shallow_data {
> > struct strbuf *out;
> > @@ -261,7 +262,11 @@ static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
> > const char *hex = oid_to_hex(&graft->oid);
> > if (graft->nr_parent != -1)
> > return 0;
> > - if (data->flags & SEEN_ONLY) {
> > + if (data->flags & QUICK_PRUNE) {
> > + struct commit *c = lookup_commit(the_repository, &graft->oid);
> > + if (!c || parse_commit(c))
> > + return 0;
> > + } else if (data->flags & SEEN_ONLY) {
> > struct commit *c = lookup_commit(the_repository, &graft->oid);
> > if (!c || !(c->object.flags & SEEN)) {
> > if (data->flags & VERBOSE)
> > @@ -371,16 +376,23 @@ void advertise_shallow_grafts(int fd)
> >
> > /*
> > * mark_reachable_objects() should have been run prior to this and all
> > - * reachable commits marked as "SEEN".
> > + * reachable commits marked as "SEEN", except when quick_prune is non-zero,
> > + * in which case lines are excised from the shallow file if they refer to
> > + * commits that do not exist (any longer).
> > */
> > -void prune_shallow(int show_only)
> > +void prune_shallow(int show_only, int quick_prune)
> > {
> > struct lock_file shallow_lock = LOCK_INIT;
> > struct strbuf sb = STRBUF_INIT;
> > + unsigned flags = SEEN_ONLY;
> > int fd;
> >
> > + if (quick_prune)
> > + flags |= QUICK_PRUNE;
> > +
> > if (show_only) {
> > - write_shallow_commits_1(&sb, 0, NULL, SEEN_ONLY | VERBOSE);
> > + flags |= VERBOSE;
> > + write_shallow_commits_1(&sb, 0, NULL, flags);
> > strbuf_release(&sb);
> > return;
> > }
> > @@ -388,7 +400,7 @@ void prune_shallow(int show_only)
> > git_path_shallow(the_repository),
> > LOCK_DIE_ON_ERROR);
> > check_shallow_file_for_update(the_repository);
> > - if (write_shallow_commits_1(&sb, 0, NULL, SEEN_ONLY)) {
> > + if (write_shallow_commits_1(&sb, 0, NULL, flags)) {
> > if (write_in_full(fd, sb.buf, sb.len) < 0)
> > die_errno("failed to write to %s",
> > get_lock_file_path(&shallow_lock));
>