[PATCH v6 13/32] refs: add methods to init refs db

[David Turner <dturner@twopensource.com>]

Alternate refs backends might not need the refs/heads directory and so
on, so we make ref db initialization part of the backend.

Signed-off-by: David Turner <dturner@twopensource.com>
---
 builtin/init-db.c    | 20 ++++++++++----------
 refs.c               |  5 +++++
 refs.h               |  2 ++
 refs/files-backend.c | 16 ++++++++++++++++
 refs/refs-internal.h |  2 ++
 5 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/builtin/init-db.c b/builtin/init-db.c
index 07229d6..0c8f4ac 100644
--- a/builtin/init-db.c
+++ b/builtin/init-db.c
@@ -177,13 +177,7 @@ static int create_default_files(const char *template_path)
 	char junk[2];
 	int reinit;
 	int filemode;
-
-	/*
-	 * Create .git/refs/{heads,tags}
-	 */
-	safe_create_dir(git_path_buf(&buf, "refs"), 1);
-	safe_create_dir(git_path_buf(&buf, "refs/heads"), 1);
-	safe_create_dir(git_path_buf(&buf, "refs/tags"), 1);
+	struct strbuf err = STRBUF_INIT;
 
 	/* Just look for `init.templatedir` */
 	git_config(git_init_db_config, NULL);
@@ -207,12 +201,18 @@ static int create_default_files(const char *template_path)
 	 */
 	if (shared_repository) {
 		adjust_shared_perm(get_git_dir());
-		adjust_shared_perm(git_path_buf(&buf, "refs"));
-		adjust_shared_perm(git_path_buf(&buf, "refs/heads"));
-		adjust_shared_perm(git_path_buf(&buf, "refs/tags"));
 	}
 
 	/*
+	 * We need to create a "refs" dir in any case so that older
+	 * versions of git can tell that this is a repository.
+	 */
+	safe_create_dir(git_path("refs"), 1);
+
+	if (refs_init_db(shared_repository, &err))
+		die("failed to set up refs db: %s", err.buf);
+
+	/*
 	 * Create the default symlink from ".git/HEAD" to the "master"
 	 * branch, if it does not exist yet.
 	 */
diff --git a/refs.c b/refs.c
index 21b103c..baf83ac 100644
--- a/refs.c
+++ b/refs.c
@@ -1316,6 +1316,11 @@ const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
 }
 
 /* backend functions */
+int refs_init_db(int shared, struct strbuf *err)
+{
+	return the_refs_backend->init_db(shared, err);
+}
+
 int ref_transaction_commit(struct ref_transaction *transaction,
 			   struct strbuf *err)
 {
diff --git a/refs.h b/refs.h
index 5bc3fbc..feff82e 100644
--- a/refs.h
+++ b/refs.h
@@ -66,6 +66,8 @@ extern int ref_exists(const char *refname);
 
 extern int is_branch(const char *refname);
 
+extern int refs_init_db(int shared, struct strbuf *err);
+
 /*
  * If refname is a non-symbolic reference that refers to a tag object,
  * and the tag can be (recursively) dereferenced to a non-tag object,
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 6b15a2e..67ba4c2 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -3424,9 +3424,25 @@ static int files_reflog_expire(const char *refname, const unsigned char *sha1,
 	return -1;
 }
 
+static int files_init_db(int shared, struct strbuf *err)
+{
+	/*
+	 * Create .git/refs/{heads,tags}
+	 */
+	safe_create_dir(git_path("refs/heads"), 1);
+	safe_create_dir(git_path("refs/tags"), 1);
+	if (shared) {
+		adjust_shared_perm(git_path("refs"));
+		adjust_shared_perm(git_path("refs/heads"));
+		adjust_shared_perm(git_path("refs/tags"));
+	}
+	return 0;
+}
+
 struct ref_storage_be refs_be_files = {
 	NULL,
 	"files",
+	files_init_db,
 	files_transaction_commit,
 	files_initial_transaction_commit,
 
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index beef457..dfd0326 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -211,6 +211,7 @@ int do_for_each_per_worktree_ref(const char *submodule, const char *base,
 				 void *cb_data);
 
 /* refs backends */
+typedef int ref_init_db_fn(int shared, struct strbuf *err);
 typedef int ref_transaction_commit_fn(struct ref_transaction *transaction,
 				      struct strbuf *err);
 
@@ -255,6 +256,7 @@ typedef int do_for_each_ref_fn(const char *submodule, const char *base,
 struct ref_storage_be {
 	struct ref_storage_be *next;
 	const char *name;
+	ref_init_db_fn *init_db;
 	ref_transaction_commit_fn *transaction_commit;
 	ref_transaction_commit_fn *initial_transaction_commit;
 
-- 
2.4.2.767.g62658d5-twtrsrc