On Thu, Jan 13, 2022 at 01:43:18PM +0100, Ævar Arnfjörð Bjarmason wrote:
>
> On Thu, Jan 13 2022, Patrick Steinhardt wrote:
>
> > [[PGP Signed Part:Undecided]]
> > When deleting loose refs, then we also have to delete the refs in the
> > packed backend. This is done by calling `refs_delete_refs()`, which
> > then uses the packed-backend's logic to delete refs. This doesn't allow
> > us to exercise any control over the reference transaction which is being
> > created in the packed backend, which is required in a subsequent commit.
> >
> > Extract a new function `packed_refs_delete_refs()`, which hosts most of
> > the logic to delete refs except for creating the transaction itself.
> > Like this, we can easily create the transaction in the files backend
> > and thus exert more control over it.
> >
> > Signed-off-by: Patrick Steinhardt <ps@xxxxxx>
> > ---
> > refs/files-backend.c | 12 +++++++++---
> > refs/packed-backend.c | 28 +++++++++++++++++++++-------
> > refs/packed-backend.h | 7 +++++++
> > 3 files changed, 37 insertions(+), 10 deletions(-)
> >
> > diff --git a/refs/files-backend.c b/refs/files-backend.c
> > index 90b671025a..5795e54020 100644
> > --- a/refs/files-backend.c
> > +++ b/refs/files-backend.c
> > @@ -1249,6 +1249,7 @@ static int files_delete_refs(struct ref_store *ref_store, const char *msg,
> > {
> > struct files_ref_store *refs =
> > files_downcast(ref_store, REF_STORE_WRITE, "delete_refs");
> > + struct ref_transaction *transaction = NULL;
>
> nit: "NULL initialization never needed?
> (re: https://lore.kernel.org/git/220113.86bl0gvtq3.gmgdl@xxxxxxxxxxxxxxxxxxx/)
It is needed: if locking the packed-refs file fails we `goto error;` and
try to free the transaction without it having been initialized yet.
> > struct strbuf err = STRBUF_INIT;
> > int i, result = 0;
> >
> > @@ -1258,10 +1259,14 @@ static int files_delete_refs(struct ref_store *ref_store, const char *msg,
> > if (packed_refs_lock(refs->packed_ref_store, 0, &err))
> > goto error;
> >
> > - if (refs_delete_refs(refs->packed_ref_store, msg, refnames, flags)) {
> > - packed_refs_unlock(refs->packed_ref_store);
> > + transaction = ref_store_transaction_begin(refs->packed_ref_store, &err);
> > + if (!transaction)
> > + goto error;
> > +
> > + result = packed_refs_delete_refs(refs->packed_ref_store,
> > + transaction, msg, refnames, flags);
> > + if (result)
> > goto error;
> > - }
> >
> > packed_refs_unlock(refs->packed_ref_store);
> >
> > @@ -1288,6 +1293,7 @@ static int files_delete_refs(struct ref_store *ref_store, const char *msg,
> > else
> > error(_("could not delete references: %s"), err.buf);
> >
> > + ref_transaction_free(transaction);
> > strbuf_release(&err);
> > return -1;
> > }
> > diff --git a/refs/packed-backend.c b/refs/packed-backend.c
> > index 67152c664e..e97d67f932 100644
> > --- a/refs/packed-backend.c
> > +++ b/refs/packed-backend.c
> > @@ -1522,15 +1522,10 @@ static int packed_initial_transaction_commit(struct ref_store *ref_store,
> > static int packed_delete_refs(struct ref_store *ref_store, const char *msg,
> > struct string_list *refnames, unsigned int flags)
> > {
> > - struct packed_ref_store *refs =
> > - packed_downcast(ref_store, REF_STORE_WRITE, "delete_refs");
> > struct strbuf err = STRBUF_INIT;
> > struct ref_transaction *transaction;
> > - struct string_list_item *item;
> > int ret;
> >
> > - (void)refs; /* We need the check above, but don't use the variable */
> > -
> > if (!refnames->nr)
> > return 0;
> >
> > @@ -1544,6 +1539,27 @@ static int packed_delete_refs(struct ref_store *ref_store, const char *msg,
> > if (!transaction)
> > return -1;
> >
> > + ret = packed_refs_delete_refs(ref_store, transaction,
> > + msg, refnames, flags);
> > +
> > + ref_transaction_free(transaction);
> > + return ret;
> > +}
> > +
> > +int packed_refs_delete_refs(struct ref_store *ref_store,
> > + struct ref_transaction *transaction,
> > + const char *msg,
> > + struct string_list *refnames,
> > + unsigned int flags)
> > +{
> > + struct packed_ref_store *refs =
> > + packed_downcast(ref_store, REF_STORE_WRITE, "delete_refs");
> > + struct strbuf err = STRBUF_INIT;
> > + struct string_list_item *item;
> > + int ret;
> > +
> > + (void)(refs); /* We need the check above, but don't use the variable */
> > +
> > for_each_string_list_item(item, refnames) {
> > if (ref_transaction_delete(transaction, item->string, NULL,
> > flags, msg, &err)) {
>
> I see you're just moving this code around, but FWIW we can just do this
> (also in the pre-image):
>
> int packed_refs_delete_refs(...)
> {
> [declare variables]
>
> /* Assert ref store sanity */
> packed_downcast(ref_store, REF_STORE_WRITE, "delete_refs")
>
> [...]
> }
>
> Not sure it's good to change it around just for this mostly-move, just a
> note...
I think this change is trivial enough to make while at it.
Patrick
> > @@ -1554,7 +1570,6 @@ static int packed_delete_refs(struct ref_store *ref_store, const char *msg,
> > }
> >
> > ret = ref_transaction_commit(transaction, &err);
> > -
>
> Stray whitespace change.
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