[PATCH v2 2/6] odb: make backend-specific fields optional
From: Patrick Steinhardt <hidden>
Date: 2026-07-02 12:02:10
Subsystem:
the rest · Maintainer:
Linus Torvalds
The `struct object_info` carries two pieces of information
about how an object was looked up:
- The `whence` enum identifying the backend.
- The backend-tagged union `u` exposing backend-specific details
(currently only the packed-source case, which records the owning
pack, offset and packed object type).
The union is populated unconditionally, even though most callers don't
care about provenance at all.
Split the backend-specific union out into a new public type, `struct
object_info_source`, and make the object info structure carry it via
just another opt-in request pointer. As with all the other requestable
information, callers that need source info allocate a `struct
object_info_source` on the stack and point `sourcep` at it; callers that
don't care about it simply leave the field as a `NULL` pointer. Adapt
callers accordingly.
Note that the `whence` enum is strictly-speaking also backend-specific
information, so it would be another good candidate to be moved into the
`struct object_info_source`. For now though it is left alone, as it will
be replaced by a `struct odb_source` pointer in a subsequent commit.
Signed-off-by: Patrick Steinhardt <redacted>
---
builtin/cat-file.c | 8 +++++--
builtin/index-pack.c | 8 +++++--
builtin/pack-objects.c | 15 +++++++++----
odb.c | 3 ++-
odb.h | 60 +++++++++++++++++++++++++++++++++-----------------
packfile.c | 33 ++++++++++++++-------------
reachable.c | 5 ++++-
7 files changed, 87 insertions(+), 45 deletions(-)
diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index 8726485f1f..adc626ce30 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c@@ -835,7 +835,8 @@ static int batch_one_object_oi(const struct object_id *oid, { struct for_each_object_payload *payload = _payload; if (oi && oi->whence == OI_PACKED) - return payload->callback(oid, oi->u.packed.pack, oi->u.packed.offset, + return payload->callback(oid, oi->sourcep->u.packed.pack, + oi->sourcep->u.packed.offset, payload->payload); return payload->callback(oid, NULL, 0, payload->payload); }
@@ -906,7 +907,10 @@ static void batch_each_object(struct batch_options *opt, &payload, flags); } } else { - struct object_info oi = { 0 }; + struct object_info_source oi_source; + struct object_info oi = { + .sourcep = &oi_source, + }; for (source = the_repository->objects->sources; source; source = source->next) { struct odb_source_files *files = odb_source_files_downcast(source);
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index f396658468..77af26db8f 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c@@ -1825,11 +1825,15 @@ static void repack_local_links(void) oidset_iter_init(&outgoing_links, &iter); while ((oid = oidset_iter_next(&iter))) { - struct object_info info = OBJECT_INFO_INIT; + struct object_info_source info_source; + struct object_info info = { + .sourcep = &info_source, + }; + if (odb_read_object_info_extended(the_repository->objects, oid, &info, 0)) /* Missing; assume it is a promisor object */ continue; - if (info.whence == OI_PACKED && info.u.packed.pack->pack_promisor) + if (info.whence == OI_PACKED && info_source.u.packed.pack->pack_promisor) continue; if (!cmd.args.nr) {
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 620d9ce085..9deb37e9e8 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c@@ -4491,8 +4491,9 @@ static int add_object_in_unpacked_pack(const struct object_id *oid, void *data UNUSED) { if (cruft) { - add_cruft_object_entry(oid, OBJ_NONE, oi->u.packed.pack, - oi->u.packed.offset, NULL, *oi->mtimep); + add_cruft_object_entry(oid, OBJ_NONE, oi->sourcep->u.packed.pack, + oi->sourcep->u.packed.offset, NULL, + *oi->mtimep); } else { add_object_entry(oid, OBJ_NONE, "", 0); }
@@ -4509,8 +4510,10 @@ static void add_objects_in_unpacked_packs(void) ODB_FOR_EACH_OBJECT_SKIP_IN_CORE_KEPT_PACKS | ODB_FOR_EACH_OBJECT_SKIP_ON_DISK_KEPT_PACKS, }; + struct object_info_source oi_source; struct object_info oi = { .mtimep = &mtime, + .sourcep = &oi_source, }; odb_prepare_alternates(to_pack.repo->objects);
@@ -5000,10 +5003,14 @@ static int option_parse_cruft_expiration(const struct option *opt UNUSED, static int is_not_in_promisor_pack_obj(struct object *obj, void *data UNUSED) { - struct object_info info = OBJECT_INFO_INIT; + struct object_info_source info_source; + struct object_info info = { + .sourcep = &info_source, + }; + if (odb_read_object_info_extended(the_repository->objects, &obj->oid, &info, 0)) BUG("should_include_obj should only be called on existing objects"); - return info.whence != OI_PACKED || !info.u.packed.pack->pack_promisor; + return info.whence != OI_PACKED || !info_source.u.packed.pack->pack_promisor; } static int is_not_in_promisor_pack(struct commit *commit, void *data) {
diff --git a/odb.c b/odb.c
index 7d555be09f..99f4e7551c 100644
--- a/odb.c
+++ b/odb.c@@ -692,7 +692,8 @@ static int oid_object_info_convert(struct repository *r, } } input_oi->whence = new_oi.whence; - input_oi->u = new_oi.u; + if (input_oi->sourcep) + *input_oi->sourcep = *new_oi.sourcep; return ret; }
diff --git a/odb.h b/odb.h
index 3834a0dcbf..770900289a 100644
--- a/odb.h
+++ b/odb.h@@ -248,6 +248,38 @@ int odb_pretend_object(struct object_database *odb, void *buf, size_t len, enum object_type type, struct object_id *oid); +/* + * Object information that can be used to uniquely identify an object and learn + * more about how exactly it is stored. + */ +struct object_info_source { + /* + * Backend-specific information about the specific object. This can be + * used for example to uniquely identify a given object in case it + * exists multiple times. + */ + union { + /* + * struct { + * ... Nothing to expose in this case + * } cached; + * struct { + * ... Nothing to expose in this case + * } loose; + */ + struct { + struct packed_git *pack; + off_t offset; + enum packed_object_type { + PACKED_OBJECT_TYPE_UNKNOWN, + PACKED_OBJECT_TYPE_FULL, + PACKED_OBJECT_TYPE_OFS_DELTA, + PACKED_OBJECT_TYPE_REF_DELTA, + } type; + } packed; + } u; +}; + struct object_info { /* Request */ enum object_type *typep;
@@ -269,32 +301,20 @@ struct object_info { */ time_t *mtimep; + /* + * Backend-specific information that tells the caller where exactly an + * object was looked up from. This information should help disambiguate + * object lookups in case the same object exists in multiple sources, + * or multiple times in the same source. + */ + struct object_info_source *sourcep; + /* Response */ enum { OI_CACHED, OI_LOOSE, OI_PACKED, } whence; - union { - /* - * struct { - * ... Nothing to expose in this case - * } cached; - * struct { - * ... Nothing to expose in this case - * } loose; - */ - struct { - struct packed_git *pack; - off_t offset; - enum packed_object_type { - PACKED_OBJECT_TYPE_UNKNOWN, - PACKED_OBJECT_TYPE_FULL, - PACKED_OBJECT_TYPE_OFS_DELTA, - PACKED_OBJECT_TYPE_REF_DELTA, - } type; - } packed; - } u; }; /*
diff --git a/packfile.c b/packfile.c
index 2b741d7a76..688c410b35 100644
--- a/packfile.c
+++ b/packfile.c@@ -1422,22 +1422,25 @@ int packed_object_info_with_index_pos(struct odb_source_packed *source UNUSED, } oi->whence = OI_PACKED; - oi->u.packed.offset = obj_offset; - oi->u.packed.pack = p; - switch (type) { - case OBJ_NONE: - oi->u.packed.type = PACKED_OBJECT_TYPE_UNKNOWN; - break; - case OBJ_REF_DELTA: - oi->u.packed.type = PACKED_OBJECT_TYPE_REF_DELTA; - break; - case OBJ_OFS_DELTA: - oi->u.packed.type = PACKED_OBJECT_TYPE_OFS_DELTA; - break; - default: - oi->u.packed.type = PACKED_OBJECT_TYPE_FULL; - break; + if (oi->sourcep) { + oi->sourcep->u.packed.offset = obj_offset; + oi->sourcep->u.packed.pack = p; + + switch (type) { + case OBJ_NONE: + oi->sourcep->u.packed.type = PACKED_OBJECT_TYPE_UNKNOWN; + break; + case OBJ_REF_DELTA: + oi->sourcep->u.packed.type = PACKED_OBJECT_TYPE_REF_DELTA; + break; + case OBJ_OFS_DELTA: + oi->sourcep->u.packed.type = PACKED_OBJECT_TYPE_OFS_DELTA; + break; + default: + oi->sourcep->u.packed.type = PACKED_OBJECT_TYPE_FULL; + break; + } } ret = 0;
diff --git a/reachable.c b/reachable.c
index 101cfc2727..2fc5b82d62 100644
--- a/reachable.c
+++ b/reachable.c@@ -235,7 +235,8 @@ static int add_recent_object(const struct object_id *oid, add_pending_object(data->revs, obj, ""); if (data->cb) { if (oi->whence == OI_PACKED) - data->cb(obj, oi->u.packed.pack, oi->u.packed.offset, *oi->mtimep); + data->cb(obj, oi->sourcep->u.packed.pack, + oi->sourcep->u.packed.offset, *oi->mtimep); else data->cb(obj, NULL, 0, *oi->mtimep); }
@@ -252,9 +253,11 @@ int add_unseen_recent_objects_to_traversal(struct rev_info *revs, unsigned flags; enum object_type type; time_t mtime; + struct object_info_source oi_source; struct object_info oi = { .mtimep = &mtime, .typep = &type, + .sourcep = &oi_source, }; int r;
--
2.55.0.795.g602f6c329a.dirty