[PATCH v3 04/10] refs/files: support symbolic and root refs in initial transaction
- From
Patrick Steinhardt <ps@pks.im>
- Date
- Nov 25, 2024, 06:27 UTC
- Message-ID
- <20241125-pks-refs-optimize-migrations-v3-4-17bc85e33ad7@pks.im>
- In-Reply-To
- <20241125-pks-refs-optimize-migrations-v3-0-17bc85e33ad7@pks.im>
The "files" backend has implemented special logic when committing the first transactions in an otherwise empty ref store: instead of writing all refs as separate loose files, it instead knows to write them all into a "packed-refs" file directly. This is significantly more efficient than having to write each of the refs as separate "loose" ref.
The only user of this optimization is git-clone(1), which only uses this mechanism to write regular refs. Consequently, the implementation does not know how to handle both symbolic and root refs. While fine in the context of git-clone(1), this keeps us from using the mechanism in more cases.
Adapt the logic to also support symbolic and root refs by using a second transaction that we use for all of the refs that need to be written as loose refs.
Signed-off-by: Patrick Steinhardt <ps@pks.im> --- refs/files-backend.c | 44 ++++++++++++++++++++++++++++++++++---------- 1 file changed, 34 insertions(+), 10 deletions(-)
diff --git a/refs/files-backend.c b/refs/files-backend.c index 3ed18475a72aa4798d15b2912c37b4caabd47aac..116d4259697b20583cb2db34ed47025e8781cd42 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -2995,6 +2995,7 @@ static int files_transaction_finish_initial(struct files_ref_store *refs, int ret = 0; struct string_list affected_refnames = STRING_LIST_INIT_NODUP; struct ref_transaction *packed_transaction = NULL; + struct ref_transaction *loose_transaction = NULL; assert(err); @@ -3040,6 +3041,7 @@ static int files_transaction_finish_initial(struct files_ref_store *refs, if ((update->flags & REF_HAVE_OLD) && !is_null_oid(&update->old_oid)) BUG("initial ref transaction with old_sha1 set"); + if (refs_verify_refname_available(&refs->base, update->refname, &affected_refnames, NULL, err)) { @@ -3048,26 +3050,48 @@ static int files_transaction_finish_initial(struct files_ref_store *refs, } /* - * Add a reference creation for this reference to the - * packed-refs transaction: + * packed-refs don't support symbolic refs and root refs, so we + * have to queue these references via the loose transaction. */ - ref_transaction_add_update(packed_transaction, update->refname, - update->flags & ~REF_HAVE_OLD, - &update->new_oid, &update->old_oid, - NULL, NULL, NULL); + if (update->new_target || is_root_ref(update->refname)) { + if (!loose_transaction) { + loose_transaction = ref_store_transaction_begin(&refs->base, 0, err); + if (!loose_transaction) { + ret = TRANSACTION_GENERIC_ERROR; + goto cleanup; + } + } + + ref_transaction_add_update(loose_transaction, update->refname, + update->flags & ~REF_HAVE_OLD, + update->new_target ? NULL : &update->new_oid, NULL, + update->new_target, NULL, NULL); + } else { + ref_transaction_add_update(packed_transaction, update->refname, + update->flags & ~REF_HAVE_OLD, + &update->new_oid, &update->old_oid, + NULL, NULL, NULL); + } } - if (packed_refs_lock(refs->packed_ref_store, 0, err)) { + if (packed_refs_lock(refs->packed_ref_store, 0, err) || + ref_transaction_commit(packed_transaction, err)) { ret = TRANSACTION_GENERIC_ERROR; goto cleanup; } + packed_refs_unlock(refs->packed_ref_store); - if (ref_transaction_commit(packed_transaction, err)) { - ret = TRANSACTION_GENERIC_ERROR; + if (loose_transaction) { + if (ref_transaction_prepare(loose_transaction, err) || + ref_transaction_commit(loose_transaction, err)) { + ret = TRANSACTION_GENERIC_ERROR; + goto cleanup; + } } - packed_refs_unlock(refs->packed_ref_store); cleanup: + if (loose_transaction) + ref_transaction_free(loose_transaction); if (packed_transaction) ref_transaction_free(packed_transaction); transaction->state = REF_TRANSACTION_CLOSED;
-- 2.47.0.274.g962d0b743d.dirty