kernel
/
git
mirror of https://git.kernel.org/pub/scm/git/git.git
1
0
Fork 0
Code Releases Activity

builtin/clone: defer setup of the object database 

When cloning a repository we defer initialization of the reference
database. This is because we don't yet know all details required for us
to initialize the refdb in the first place. Most importantly, what we
are missing is information about the object hash.

We don't do the same thing for the object database yet, but here we
essentially have the same problem. While the "files" database does not
need any information about the object format at creation time, alternate
backends are likely to require that information so that they can
properly set up their data structures.

Besides this forward-looking future proofing though, we also have a
second use case for deferring initialization of the object database,
namely alternates. When initializing the object database we do not yet
know whether we'll need alternates or not because this depends on the
repository we're about to clone from. If it is a local repository and
the user has passed "--refernce{,-if-able}", then we will end up writing
alternates into the object database.

The ugly part though is that we cannot determine where the repository is
getting cloned from before it has been initialized. While we of course
already have access to the user-provided URI, that URI can be very well
rewritten via "url.<base>.insteadOf". We can of course read the global-
and system-level configuration to resolve it. But we explicitly resolve
the URI a second time after we have initialized the repository because
it can happen that we copy a ".git/config" over from our templates, and
that file may cause us to rewrite the path.

In a subsequent commit though we'll start to write alternates as part of
the repository initialization, so we'll need to have the URI properly
resolved before we can initialize the object database. This is ugly, but
as mentioned above it makes sense for us to defer its initialization
anyway so that we also know about the object hash already.

Introduce a new flag that makes `init_db()` skip initializing the object
database. Expose `create_object_database()` and make use of it after we
have resolved the URI.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
jch
Patrick Steinhardt 2026-08-31 12:02:05 +02:00 committed by Junio C Hamano
parent 02e44450dd
commit ef8fb7fd96
3 changed files with 23 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
builtin/clone.c
View File

@ -1184,11 +1184,14 @@ int cmd_clone(int argc,
* database. We do not yet know about the object format of the
* repository, and reference backends may persist that information into
* their on-disk data structures.
*
* Furthermore, we skip initializing the object database so that we can
* first resolve potential alternates before creating it.
*/
init_db(the_repository, git_dir, real_git_dir, work_tree, option_template,
GIT_HASH_UNKNOWN, ref_storage_format, NULL,
do_not_override_repo_unix_permissions,
INIT_DB_QUIET | INIT_DB_SKIP_REFDB);
INIT_DB_QUIET | INIT_DB_SKIP_REFDB | INIT_DB_SKIP_ODB);

if (real_git_dir) {
free((char *)git_dir);
@ -1311,9 +1314,6 @@ int cmd_clone(int argc,
strbuf_reset(&key);
}

if (option_required_reference.nr || option_optional_reference.nr)
setup_reference();

remote = remote_get_early(remote_name);

if (!option_rev)
@ -1342,6 +1342,10 @@ int cmd_clone(int argc,
if (option_local > 0 && !is_local)
warning(_("--local is ignored"));

create_object_database(the_repository);
if (option_required_reference.nr || option_optional_reference.nr)
setup_reference();

transport = transport_get(remote, path ? path : remote->url.v[0]);
transport_set_verbosity(transport, option_verbosity, option_progress);
transport->family = family;

8
setup.c
View File

@ -2647,7 +2647,7 @@ static int create_default_files(struct repository *repo,
return reinit;
}

static void create_object_database(struct repository *repo)
void create_object_database(struct repository *repo)
{
/*
* Create the "objects" directory in the common directory. This is done
@ -2829,7 +2829,8 @@ int init_db(struct repository *repo,
const char *template_dir, int hash,
enum ref_storage_format ref_storage_format,
const char *initial_branch,
int init_shared_repository, unsigned int flags)
int init_shared_repository,
enum init_db_flags flags)
{
int reinit;
int exist_ok = flags & INIT_DB_EXIST_OK;
@ -2903,7 +2904,8 @@ int init_db(struct repository *repo,

if (!(flags & INIT_DB_SKIP_REFDB))
create_reference_database(repo, initial_branch, flags & INIT_DB_QUIET);
create_object_database(repo);
if (!(flags & INIT_DB_SKIP_ODB))
create_object_database(repo);

startup_info->have_repository = 1;


15
setup.h
View File

@ -256,9 +256,12 @@ int apply_repository_format(struct repository *repo,

const char *get_template_dir(const char *option_template);

#define INIT_DB_QUIET (1 << 0)
#define INIT_DB_EXIST_OK (1 << 1)
#define INIT_DB_SKIP_REFDB (1 << 2)
enum init_db_flags {
INIT_DB_QUIET = (1 << 0),
INIT_DB_EXIST_OK = (1 << 1),
INIT_DB_SKIP_REFDB = (1 << 2),
INIT_DB_SKIP_ODB = (1 << 3),
};

int init_db(struct repository *repo,
const char *git_dir,
@ -266,13 +269,15 @@ int init_db(struct repository *repo,
const char *worktree,
const char *template_dir, int hash_algo,
enum ref_storage_format ref_storage_format,
const char *initial_branch, int init_shared_repository,
unsigned int flags);
const char *initial_branch,
int init_shared_repository,
enum init_db_flags flags);
void initialize_repository_version(struct repository *repo,
int hash_algo,
enum ref_storage_format ref_storage_format,
int reinit);
void create_reference_database(struct repository *repo, const char *initial_branch, int quiet);
void create_object_database(struct repository *repo);

/*
* NOTE NOTE NOTE!!