odb: move reparenting logic into respective subsystems

The primary object database source may be initialized with a relative
path. When the process changes its current working directory we thus
have to update this path and have it point to the same path, but
relative to the new working directory.

This logic is handled in the object database layer. It consists of three
steps:

  1. We undo any potential temporary object directory, which are used
     for transactions. This is done so that we don't end up modifying
     the temporary object database source that got applied for the
     transaction.

  2. We then iterate through the non-transactional sources and reparent
     their respective paths.

  3. We reapply the temporary object directory, but update its path.

All of this logic is heavily tied to how the object database source
handles paths in the first place. It's an internal implementation
detail, and as sources may not even use an on-disk path at all it is not
a mechanism that applies to all potential sources.

Refactor the code so that the logic to reparent the sources is hosted by
the "files" source and the temporary object directory subsystems,
respectively. This logic is easier to reason about, but it also ensures
that this logic is handled at the correct level.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 19 insertions, 23 deletions

diff --git a/tmp-objdir.c b/tmp-objdir.c
index 9f5a1788cd..e436eed07e 100644
--- a/tmp-objdir.c
+++ b/tmp-objdir.c
@@ -36,6 +36,21 @@ static void tmp_objdir_free(struct tmp_objdir *t)
 	free(t);
 }
 
+static void tmp_objdir_reparent(const char *name UNUSED,
+				const char *old_cwd,
+				const char *new_cwd,
+				void *cb_data)
+{
+	struct tmp_objdir *t = cb_data;
+	char *path;
+
+	path = reparent_relative_path(old_cwd, new_cwd,
+				      t->path.buf);
+	strbuf_reset(&t->path);
+	strbuf_addstr(&t->path, path);
+	free(path);
+}
+
 int tmp_objdir_destroy(struct tmp_objdir *t)
 {
 	int err;
@@ -51,6 +66,7 @@ int tmp_objdir_destroy(struct tmp_objdir *t)
 
 	err = remove_dir_recursively(&t->path, 0);
 
+	chdir_notify_unregister(NULL, tmp_objdir_reparent, t);
 	tmp_objdir_free(t);
 
 	return err;
@@ -137,6 +153,9 @@ struct tmp_objdir *tmp_objdir_create(struct repository *r,
 	strbuf_addf(&t->path, "%s/tmp_objdir-%s-XXXXXX",
 		    repo_get_object_directory(r), prefix);
 
+	if (!is_absolute_path(t->path.buf))
+		chdir_notify_register(NULL, tmp_objdir_reparent, t);
+
 	if (!mkdtemp(t->path.buf)) {
 		/* free, not destroy, as we never touched the filesystem */
 		tmp_objdir_free(t);
@@ -315,26 +334,3 @@ void tmp_objdir_replace_primary_odb(struct tmp_objdir *t, int will_destroy)
 							  t->path.buf, will_destroy);
 	t->will_destroy = will_destroy;
 }
-
-struct tmp_objdir *tmp_objdir_unapply_primary_odb(void)
-{
-	if (!the_tmp_objdir || !the_tmp_objdir->prev_source)
-		return NULL;
-
-	odb_restore_primary_source(the_tmp_objdir->repo->objects,
-				   the_tmp_objdir->prev_source, the_tmp_objdir->path.buf);
-	the_tmp_objdir->prev_source = NULL;
-	return the_tmp_objdir;
-}
-
-void tmp_objdir_reapply_primary_odb(struct tmp_objdir *t, const char *old_cwd,
-		const char *new_cwd)
-{
-	char *path;
-
-	path = reparent_relative_path(old_cwd, new_cwd, t->path.buf);
-	strbuf_reset(&t->path);
-	strbuf_addstr(&t->path, path);
-	free(path);
-	tmp_objdir_replace_primary_odb(t, t->will_destroy);
-}