[RFC] notes: avoid recommitting identical trees

From

Michael J Gruber <git@drmicha.warpmail.net>

Date

Aug 31, 2010, 15:16 UTC

Message-ID

<bc44b3393db4018487bb956d00a12fa73f04ca9e.1283267564.git.git@drmicha.warpmail.net>

In-Reply-To

<4C7CD65F.10509@atlas-elektronik.com>

Change this to avoid unnecessary notes commits.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
---
I can't believe there's no easier way to lookup the sha1 of a tree of a commit
but I didn't find any, and I did not want to employ the diff machinery for diffing
the trees when their sha1 is (should be) known.

 builtin/notes.c |   14 +++++++++-----
 1 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/builtin/notes.c b/builtin/notes.c
index fbc347c..48da228 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -303,11 +303,15 @@ int commit_notes(struct notes_tree *t, const char *msg)
 		hashclr(prev_commit);
 		parent = NULL;
 	}
-	if (commit_tree(buf.buf + 7, tree_sha1, parent, new_commit, NULL))
-		die("Failed to commit notes tree to database");
-
-	/* Update notes ref with new commit */
-	update_ref(buf.buf, t->ref, new_commit, prev_commit, 0, DIE_ON_ERR);
+	if (!parent || parse_commit(parent->item) || parse_tree(parent->item->tree) ||
+		hashcmp(parent->item->tree->object.sha1, tree_sha1)) {
+		/* avoid recommitting the same tree */
+		if (commit_tree(buf.buf + 7, tree_sha1, parent, new_commit, NULL))
+			die("Failed to commit notes tree to database");
+
+		/* Update notes ref with new commit */
+		update_ref(buf.buf, t->ref, new_commit, prev_commit, 0, DIE_ON_ERR);
+	}
 
 	strbuf_release(&buf);
 	return 0;

-- 
1.7.2.2.398.g5af70