refs: extract out `refs_create_refdir_stubs()`

For Git to recognize a directory as a Git directory, it requires the
directory to contain:

  1. 'HEAD' file
  2. 'objects/' directory
  3. 'refs/' directory

Here, #1 and #3 are part of the reference storage mechanism,
specifically the files backend. Since then, newer backends such as the
reftable backend have moved to using their own path ('reftable/') for
storing references. But to ensure Git still recognizes the directory as
a Git directory, we create stubs.

There are two locations where we create stubs:

- In 'refs/reftable-backend.c' when creating the reftable backend.
- In 'clone.c' before spawning transport helpers.

In a following commit, we'll add another instance. So instead of
repeating the code, let's extract out this code to
`refs_create_refdir_stubs()` and use it.

Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/clone.c b/builtin/clone.c
index cd43bb5aa22a7661cab3e432a37edb574b477b64..697c5bb5cbd677603cd97d8eb60fd6ab84506752 100644 (file)
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -1225,12 +1225,7 @@ int cmd_clone(int argc,
        initialize_repository_version(GIT_HASH_UNKNOWN,
                                      the_repository->ref_storage_format, 1);
 
-       strbuf_addf(&buf, "%s/HEAD", git_dir);
-       write_file(buf.buf, "ref: refs/heads/.invalid");
-
-       strbuf_reset(&buf);
-       strbuf_addf(&buf, "%s/refs", git_dir);
-       safe_create_dir(the_repository, buf.buf, 1);
+       refs_create_refdir_stubs(the_repository, git_dir, NULL);
 
        /*
         * additional config can be injected with -c, make sure it's included

diff --git a/refs.c b/refs.c
index 627b7f8698d044643cfa2397318aebed240c86fe..77b93d655b277360e8c017b4cb43b8645c186b1d 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -2163,6 +2163,29 @@ const char *refs_resolve_ref_unsafe(struct ref_store *refs,
        return NULL;
 }
 
+void refs_create_refdir_stubs(struct repository *repo, const char *refdir,
+                             const char *refs_heads_content)
+{
+       struct strbuf path = STRBUF_INIT;
+
+       strbuf_addf(&path, "%s/HEAD", refdir);
+       write_file(path.buf, "ref: refs/heads/.invalid");
+       adjust_shared_perm(repo, path.buf);
+
+       strbuf_reset(&path);
+       strbuf_addf(&path, "%s/refs", refdir);
+       safe_create_dir(repo, path.buf, 1);
+
+       if (refs_heads_content) {
+               strbuf_reset(&path);
+               strbuf_addf(&path, "%s/refs/heads", refdir);
+               write_file(path.buf, "%s", refs_heads_content);
+               adjust_shared_perm(repo, path.buf);
+       }
+
+       strbuf_release(&path);
+}
+
 /* backend functions */
 int ref_store_create_on_disk(struct ref_store *refs, int flags, struct strbuf *err)
 {

diff --git a/refs.h b/refs.h
index f0abfa1d93633e1bc2cb0aa2e1789935c6431aa5..a35fdc66420a0935d2228297d7988a9a32df90b3 100644 (file)
--- a/refs.h
+++ b/refs.h
@@ -1427,4 +1427,17 @@ void ref_iterator_free(struct ref_iterator *ref_iterator);
 int do_for_each_ref_iterator(struct ref_iterator *iter,
                             each_ref_fn fn, void *cb_data);
 
+/*
+ * Git only recognizes a directory as a repository if it contains:
+ * - HEAD file
+ * - refs/ folder
+ * While it is necessary within the files backend, newer backends may not
+ * follow the same structure. To go around this, we create stubs as necessary.
+ *
+ * If provided with a 'refs_heads_content', we create the 'refs/heads/head' file
+ * with the provided message.
+ */
+void refs_create_refdir_stubs(struct repository *repo, const char *refdir,
+                             const char *refs_heads_content);
+
 #endif /* REFS_H */

diff --git a/refs/reftable-backend.c b/refs/reftable-backend.c
index fe74af73afdb7ab891bfad902e665537d9696d83..d8651fe77945056c0e17a6f3fd350b695ae7234a 100644 (file)
--- a/refs/reftable-backend.c
+++ b/refs/reftable-backend.c
@@ -491,18 +491,8 @@ static int reftable_be_create_on_disk(struct ref_store *ref_store,
        safe_create_dir(the_repository, sb.buf, 1);
        strbuf_reset(&sb);
 
-       strbuf_addf(&sb, "%s/HEAD", refs->base.gitdir);
-       write_file(sb.buf, "ref: refs/heads/.invalid");
-       adjust_shared_perm(the_repository, sb.buf);
-       strbuf_reset(&sb);
-
-       strbuf_addf(&sb, "%s/refs", refs->base.gitdir);
-       safe_create_dir(the_repository, sb.buf, 1);
-       strbuf_reset(&sb);
-
-       strbuf_addf(&sb, "%s/refs/heads", refs->base.gitdir);
-       write_file(sb.buf, "this repository uses the reftable format");
-       adjust_shared_perm(the_repository, sb.buf);
+       refs_create_refdir_stubs(the_repository, refs->base.gitdir,
+                                "this repository uses the reftable format");
 
        strbuf_release(&sb);
        return 0;