[PATCH v4 05/14] refs: expose peeled object ID via the iterator
- From
Patrick Steinhardt <ps@pks.im>
- Date
- Oct 23, 2025, 07:16 UTC
- Message-ID
- <20251023-b4-pks-ref-filter-skip-parsing-objects-v4-5-2be68ce82c9a@pks.im>
- In-Reply-To
- <20251023-b4-pks-ref-filter-skip-parsing-objects-v4-0-2be68ce82c9a@pks.im>
Both the "files" and "reftable" backend are able to store peeled values for tags in the respective formats. This allows for a more efficient lookup of the target object of such a tag without having to manually peel via the object database.
The infrastructure to access these peeled object IDs is somewhat funky though. When iterating through objects, we store a pointer reference to the current iterator in a global variable. The callbacks invoked by that iterator are then expected to call `peel_iterated_oid()`, which checks whether the globally-stored iterator's current reference refers to the one handed into that function. If so, we ask the iterator to peel the object, otherwise we manually peel the object via the object database. Depending on global state like this is somewhat weird and also quite fragile.
Introduce a new `struct reference::peeled_oid` field that can be populated by the reference backends. This field can be accessed via a new function `reference_get_peeled_oid()` that either uses that value, if set, or alternatively peels via the ODB. With this change we don't have to rely on global state anymore, but make the peeled object ID available to the callback functions directly.
Adjust trivial callers that already have a `struct reference` available. Remaining callers will be adjusted in subsequent commits.
Signed-off-by: Patrick Steinhardt <ps@pks.im> --- builtin/describe.c | 2 +- builtin/gc.c | 2 +- builtin/pack-objects.c | 7 ++++--- commit-graph.c | 2 +- ls-refs.c | 2 +- midx-write.c | 2 +- pseudo-merge.c | 2 +- refs.c | 12 ++++++++++++ refs.h | 19 +++++++++++++++++++ refs/packed-backend.c | 1 + refs/reftable-backend.c | 5 +++++ repack-midx.c | 2 +- 12 files changed, 48 insertions(+), 10 deletions(-)
diff --git a/builtin/describe.c b/builtin/describe.c index 79545350443..443546aaac9 100644 --- a/builtin/describe.c +++ b/builtin/describe.c @@ -208,7 +208,7 @@ static int get_name(const struct reference *ref, void *cb_data UNUSED) } /* Is it annotated? */ - if (!peel_iterated_oid(the_repository, ref->oid, &peeled)) { + if (!reference_get_peeled_oid(the_repository, ref, &peeled)) { is_annotated = !oideq(ref->oid, &peeled); } else { oidcpy(&peeled, ref->oid); diff --git a/builtin/gc.c b/builtin/gc.c index 9de5de175f6..f0cf20d4238 100644 --- a/builtin/gc.c +++ b/builtin/gc.c @@ -1109,7 +1109,7 @@ static int dfs_on_ref(const struct reference *ref, void *cb_data) struct commit_list *stack = NULL; struct commit *commit; - if (!peel_iterated_oid(the_repository, ref->oid, &peeled)) + if (!reference_get_peeled_oid(the_repository, ref, &peeled)) maybe_peeled = &peeled; if (odb_read_object_info(the_repository->objects, maybe_peeled, NULL) != OBJ_COMMIT) return 0; diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c index 39633a0158e..1613fecb669 100644 --- a/builtin/pack-objects.c +++ b/builtin/pack-objects.c @@ -838,7 +838,7 @@ static int mark_tagged(const struct reference *ref, void *cb_data UNUSED) if (entry) entry->tagged = 1; - if (!peel_iterated_oid(the_repository, ref->oid, &peeled)) { + if (!reference_get_peeled_oid(the_repository, ref, &peeled)) { entry = packlist_find(&to_pack, &peeled); if (entry) entry->tagged = 1; @@ -3309,7 +3309,8 @@ static int add_ref_tag(const struct reference *ref, void *cb_data UNUSED) { struct object_id peeled; - if (!peel_iterated_oid(the_repository, ref->oid, &peeled) && obj_is_packed(&peeled)) + if (!reference_get_peeled_oid(the_repository, ref, &peeled) && + obj_is_packed(&peeled)) add_tag_chain(ref->oid); return 0; } @@ -4537,7 +4538,7 @@ static int mark_bitmap_preferred_tip(const struct reference *ref, void *data UNU struct object_id peeled; struct object *object; - if (!peel_iterated_oid(the_repository, ref->oid, &peeled)) + if (!reference_get_peeled_oid(the_repository, ref, &peeled)) maybe_peeled = &peeled; object = parse_object_or_die(the_repository, maybe_peeled, ref->name); diff --git a/commit-graph.c b/commit-graph.c index f91af416259..80be2ff2c39 100644 --- a/commit-graph.c +++ b/commit-graph.c @@ -1857,7 +1857,7 @@ static int add_ref_to_set(const struct reference *ref, void *cb_data) struct object_id peeled; struct refs_cb_data *data = (struct refs_cb_data *)cb_data; - if (!peel_iterated_oid(data->repo, ref->oid, &peeled)) + if (!reference_get_peeled_oid(data->repo, ref, &peeled)) maybe_peeled = &peeled; if (odb_read_object_info(data->repo->objects, maybe_peeled, NULL) == OBJ_COMMIT) oidset_insert(data->commits, maybe_peeled); diff --git a/ls-refs.c b/ls-refs.c index 64d02723691..8641281b86c 100644 --- a/ls-refs.c +++ b/ls-refs.c @@ -110,7 +110,7 @@ static int send_ref(const struct reference *ref, void *cb_data) if (data->peel && ref->oid) { struct object_id peeled; - if (!peel_iterated_oid(the_repository, ref->oid, &peeled)) + if (!reference_get_peeled_oid(the_repository, ref, &peeled)) strbuf_addf(&data->buf, " peeled:%s", oid_to_hex(&peeled)); } diff --git a/midx-write.c b/midx-write.c index f4dd875747a..23e61cb0001 100644 --- a/midx-write.c +++ b/midx-write.c @@ -709,7 +709,7 @@ static int add_ref_to_pending(const struct reference *ref, void *cb_data) return 0; } - if (!peel_iterated_oid(revs->repo, ref->oid, &peeled)) + if (!reference_get_peeled_oid(revs->repo, ref, &peeled)) maybe_peeled = &peeled; object = parse_object_or_die(revs->repo, maybe_peeled, ref->name); diff --git a/pseudo-merge.c b/pseudo-merge.c index 0abd51b42c1..a2d5bd85f95 100644 --- a/pseudo-merge.c +++ b/pseudo-merge.c @@ -230,7 +230,7 @@ static int find_pseudo_merge_group_for_ref(const struct reference *ref, void *_d uint32_t i; int has_bitmap; - if (!peel_iterated_oid(the_repository, ref->oid, &peeled)) + if (!reference_get_peeled_oid(the_repository, ref, &peeled)) maybe_peeled = &peeled; c = lookup_commit(the_repository, maybe_peeled); diff --git a/refs.c b/refs.c index f96cf43b128..1b1551f9814 100644 --- a/refs.c +++ b/refs.c @@ -2334,6 +2334,18 @@ int peel_iterated_oid(struct repository *r, const struct object_id *base, struct return peel_object(r, base, peeled) ? -1 : 0; } +int reference_get_peeled_oid(struct repository *repo, + const struct reference *ref, + struct object_id *peeled_oid) +{ + if (ref->peeled_oid) { + oidcpy(peeled_oid, ref->peeled_oid); + return 0; + } + + return peel_object(repo, ref->oid, peeled_oid) ? -1 : 0; +} + int refs_update_symref(struct ref_store *refs, const char *ref, const char *target, const char *logmsg) { diff --git a/refs.h b/refs.h index 4f0a685714f..886ed2c0f43 100644 --- a/refs.h +++ b/refs.h @@ -371,10 +371,29 @@ struct reference { */ const struct object_id *oid; + /* + * An optional peeled object ID. This field _may_ be set for tags in + * case the peeled value is present in the backend. Please refer to + * `reference_get_peeled_oid()`. + */ + const struct object_id *peeled_oid; + /* A bitfield of `enum reference_status` flags. */ unsigned flags; }; +/* + * Peel the tag to a non-tag commit. If present, this uses the peeled object ID + * exposed by the reference backend. Otherwise, the object is peeled via the + * object database, which is less efficient. + * + * Return `0` if the reference could be peeled, a negative error code + * otherwise. + */ +int reference_get_peeled_oid(struct repository *repo, + const struct reference *ref, + struct object_id *peeled_oid); + /* * The signature for the callback function for the for_each_*() * functions below. The memory pointed to by the `struct reference` diff --git a/refs/packed-backend.c b/refs/packed-backend.c index 711e07f8326..1fefefd54ed 100644 --- a/refs/packed-backend.c +++ b/refs/packed-backend.c @@ -963,6 +963,7 @@ static int next_record(struct packed_ref_iterator *iter) iter->base.ref.flags &= ~REF_KNOWS_PEELED; } else { iter->base.ref.flags |= REF_KNOWS_PEELED; + iter->base.ref.peeled_oid = &iter->peeled; } } else { oidclr(&iter->peeled, iter->repo->hash_algo); diff --git a/refs/reftable-backend.c b/refs/reftable-backend.c index 728886eafd3..e214e120d77 100644 --- a/refs/reftable-backend.c +++ b/refs/reftable-backend.c @@ -547,6 +547,7 @@ struct reftable_ref_iterator { struct reftable_iterator iter; struct reftable_ref_record ref; struct object_id oid; + struct object_id peeled_oid; char *prefix; size_t prefix_len; @@ -671,6 +672,8 @@ static int reftable_ref_iterator_advance(struct ref_iterator *ref_iterator) case REFTABLE_REF_VAL2: oidread(&iter->oid, iter->ref.value.val2.value, refs->base.repo->hash_algo); + oidread(&iter->peeled_oid, iter->ref.value.val2.target_value, + refs->base.repo->hash_algo); break; case REFTABLE_REF_SYMREF: referent = refs_resolve_ref_unsafe(&iter->refs->base, @@ -708,6 +711,8 @@ static int reftable_ref_iterator_advance(struct ref_iterator *ref_iterator) iter->base.ref.name = iter->ref.refname; iter->base.ref.target = referent; iter->base.ref.oid = &iter->oid; + if (iter->ref.value_type == REFTABLE_REF_VAL2) + iter->base.ref.peeled_oid = &iter->peeled_oid; iter->base.ref.flags = flags; break; diff --git a/repack-midx.c b/repack-midx.c index 349f7e20b53..74bdfa3a6e9 100644 --- a/repack-midx.c +++ b/repack-midx.c @@ -22,7 +22,7 @@ static int midx_snapshot_ref_one(const struct reference *ref, void *_data) const struct object_id *maybe_peeled = ref->oid; struct object_id peeled; - if (!peel_iterated_oid(data->repo, ref->oid, &peeled)) + if (!reference_get_peeled_oid(data->repo, ref, &peeled)) maybe_peeled = &peeled; if (oidset_insert(&data->seen, maybe_peeled))
-- 2.51.1.930.gacf6e81ea2.dirty