Subject: [PATCH 0/6] worktree: initialize refdb via ref backends

From: Patrick Steinhardt <[email-masked]>
Date: Thu, 28 Dec 2023 10:59:47 +0100

Hi,

when initializing worktrees we manually create the on-disk data
structures required for the ref backend in "worktree.c". This works just
fine right now where we only have a single user-exposed ref backend, but
it will become unwieldy once we have multiple ref backends. This patch
series thus refactors how we initialize worktrees so that we can use
`refs_init_db()` to initialize required files for us.

This patch series conflicts with ps/refstorage-extension. The conflict
can be solved as shown below. I'm happy to defer this patch series
though until the topic has landed on `master` in case this causes
issues.

Patrick

diff --cc setup.c
index f2d55994e2,4712bba6f8..0000000000
--- a/setup.c
+++ b/setup.c
@@@ -1904,7 -1926,23 +1926,8 @@@ void create_reference_database(int ref_
  	struct strbuf err = STRBUF_INIT;
  	int reinit = is_reinit();
  
 -	/*
 -	 * We need to create a "refs" dir in any case so that older versions of
 -	 * Git can tell that this is a repository. This serves two main purposes:
 -	 *
 -	 * - Clients will know to stop walking the parent-directory chain when
 -	 *   detecting the Git repository. Otherwise they may end up detecting
 -	 *   a Git repository in a parent directory instead.
 -	 *
 -	 * - Instead of failing to detect a repository with unknown reference
 -	 *   format altogether, old clients will print an error saying that
 -	 *   they do not understand the reference format extension.
 -	 */
 -	safe_create_dir(git_path("refs"), 1);
 -	adjust_shared_perm(git_path("refs"));
 -
+ 	repo_set_ref_storage_format(the_repository, ref_storage_format);
 -	if (refs_init_db(&err))
 +	if (refs_init_db(get_main_ref_store(the_repository), 0, &err))
  		die("failed to set up refs db: %s", err.buf);
  
  	/*
diff --cc worktree.c
index 085f2cc41a,9702ed0308..0000000000
--- a/worktree.c
+++ b/worktree.c
@@@ -79,7 -75,8 +80,8 @@@ static struct worktree *get_main_worktr
  	return worktree;
  }
  
- struct worktree *get_linked_worktree(const char *id)
 -static struct worktree *get_linked_worktree(const char *id,
 -					    int skip_reading_head)
++struct worktree *get_linked_worktree(const char *id,
++				     int skip_reading_head)
  {
  	struct worktree *worktree = NULL;
  	struct strbuf path = STRBUF_INIT;
diff --git a/builtin/worktree.c b/builtin/worktree.c
index 9d935bee84..558c5537f5 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -502,7 +502,7 @@ static int add_worktree(const char *path, const char *refname,
 	/*
 	 * Set up the ref store of the worktree and create the HEAD reference.
 	 */
-	wt = get_linked_worktree(name);
+	wt = get_linked_worktree(name, 1);
 	if (!wt) {
 		ret = error(_("could not find created worktree '%s'"), name);
 		goto done;
diff --git a/worktree.h b/worktree.h
index 8a75691eac..f14784a2ff 100644
--- a/worktree.h
+++ b/worktree.h
@@ -61,7 +61,8 @@ struct worktree *find_worktree(struct worktree **list,
  * Look up the worktree corresponding to `id`, or NULL of no such worktree
  * exists.
  */
-struct worktree *get_linked_worktree(const char *id);
+struct worktree *get_linked_worktree(const char *id,
+				     int skip_reading_head);
 
 /*
  * Return the worktree corresponding to `path`, or NULL if no such worktree

Patrick Steinhardt (6):
  refs: prepare `refs_init_db()` for initializing worktree refs
  setup: move creation of "refs/" into the files backend
  refs/files: skip creation of "refs/{heads,tags}" for worktrees
  builtin/worktree: move setup of commondir file earlier
  worktree: expose interface to look up worktree by name
  builtin/worktree: create refdb via ref backend

 builtin/worktree.c    | 53 ++++++++++++++++++++-----------------------
 refs.c                |  6 ++---
 refs.h                |  4 +++-
 refs/debug.c          |  4 ++--
 refs/files-backend.c  | 37 +++++++++++++++++++++++++-----
 refs/packed-backend.c |  1 +
 refs/refs-internal.h  |  4 +++-
 setup.c               | 17 +-------------
 worktree.c            | 25 ++++++++++++--------
 worktree.h            | 11 +++++++++
 10 files changed, 94 insertions(+), 68 deletions(-)

base-commit: e79552d19784ee7f4bbce278fe25f93fbda196fa
-- 
2.43.GIT